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Sample records for dentin surface micromorphology

  1. Comparative scanning electron microscopic study of the effect of different dental conditioners on dentin micromorphology

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    Alexandre Henrique Susin

    2008-04-01

    Full Text Available This study evaluated comparatively by scanning electron microscopy (SEM the effect of different dental conditioners on dentin micromorphology, when used according to the same protocol. Forty dentin sticks were obtained from 20 caries-free third human molars and were assigned to 4 groups corresponding to 3 conditioners (phosphoric acid 37%, Clearfil SE Bond and iBond and an untreated control group. After application of the conditioners, the specimens were immersed in 50% ethanol solution during 10 s, chemically fixed and dehydrated to prepare them to SEM analysis. In the control group, dentin surface was completely covered by smear layer and all dentinal tubules were occluded. In the phosphoric acid-etched group, dentin surface was completely clean and presented exposed dentinal tubule openings; this was the only group in which the tubules exhibited the funnel-shaped aspect. In the groups conditioned with Clearfil SE Bond primer and iBond, which are less acidic than phosphoric acid, tubule openings were occluded or partially occluded, though smear layer removal was observed. SE Bond was more efficient in removing the smear layer than iBond. In the Clearfil SE Bond group, the cuff-like aspect of peritubular dentin was more evident. It may be concluded all tested conditioners were able to change dentin morphology. However, it cannot be stated that the agent aggressiveness was the only cause of the micromorphological alterations because a single morphological pattern was not established for each group, but rather an association of different aspects, according to the aggressiveness of the tested conditioner.

  2. Interfacial micromorphological differences in hybrid layer formation between water- and solvent-based dentin bonding systems.

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    Gregoire, Geneviève L; Akon, Bernadette A; Millas, Arlette

    2002-06-01

    Many dentin bonding systems of different compositions, and in particular containing different solvents, have been introduced to the market. Their effect on the quality of the interface requires clarification by means of comparative trials. This study investigated micromorphological differences in hybrid layer formation with a variety of commercially available water- or solvent-based dentin bonding products and their recommended compomers. Five bonding systems were used on groups of 10 teeth each as follows: group I, acetone-based system used with 36% phosphoric acid; group II, a different acetone-based system containing nano-sized particles for filler loading and used with a non-rinsing conditioner containing maleic acid; group III, the acetone-based system of group II used with 36% phosphoric acid (the only difference in the treatment for groups II and III was the acid etching system); group IV, a mixed-solvent-based system (water/ethanol) used with 37% phosphoric acid; and group V, a water-based system used with 37% phosphoric acid. Each bonding system was covered with the recommended compomer. Class I occlusal preparations were made in extracted teeth and restored with one of the above systems. Five specimens of each group were studied with optical microscopy after staining. Scanning electron microscopy was used to examine the interface of the bonding system/dentin of the other 5 teeth in each group. The optical microscopy measurements were made with a 10 x 10 reticle. A micron mark with scale was used for the scanning electron microscope. All measurements were made in microm. The following criteria were used to define a good interface: absence of voids between the different parts of the interface, uniformity of the hybrid layer, good opening of the tubuli orifices, and tag adherence to the tubuli walls. Morphological differences were found at the interface depending on dentin treatment and adhesive composition. The acetone-containing systems were associated

  3. Micromorphological characterization of adhesive interface of sound dentin and total-etch and self-etch adhesives.

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    Drobac, Milan; Stojanac, Igor; Ramić, Bojana; Premović, Milica; Petrović, Ljubomir

    2015-01-01

    The ultimate goal in restorative dentistry has always been to achieve strong and permanent bond between the dental tissues and filling materials. It is not easy to achieve this task because the bonding process is different for enamel and dentin-dentin is more humid and more organic than enamel. It is moisture and organic nature of dentin that make this hard tissue very complex to achieve adhesive bond. One of the first and most widely used tools for examining the adhesive bond between hard dental tissues and composite restorative materials is scanning electron microscopy. The aim of this study was scanning electron microscopy analyzes the interfacial micro morphology of total-etch and self-etch adhesives. Micro morphological characteristics of interface between total-etch adhesive (Prime & Bond NT) in combination with the corresponding composite (Ceram X Mono) were compared with those of self-etching adhesive (AdheSE One) in, combination with the corresponding composite (Tetric EvoCeram). The specimens were observed under 1000 x magnification of scanning electron microscopy (JEOL, JSM-6460 Low Vacuum). Measurement of the thickness of the hybrid layer of the examined com posite systems was performed with the software of the device used (NIH Image Analyser). Micromorphological analysis of interface showed that the hybrid layer in sound dentin was well formed, its average thickness being 2.68 microm, with a large number of resin tags and a large amount of lateral branches for specimens with a composite system Prime & Bond NT-Ceram X Mono. However, the specimens' with composite systems Adhese One-Tetric EvoCeram did not show the presence of hybrid layer and the resin tags were poorly represented. The results of this study suggest that total-etch adhesives bond better with sound dentin than self-etch adhesive.

  4. Micromorphology of leaf surface of Coelogyne Lindl. species (Orchidaceae Juss. in greenhouse conditions

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    Alexander G. Gyrenko

    2013-04-01

    Full Text Available The micromorphological characteristics of both adaxial and abaxial leaf surfaces of the plants of five Coelogyne Lindl. species (C. assamicaLinden & Rchb.f., C. brachyptera Rchb.f., C. cumingii Lindl., C. fimbriataLindl., C. lentiginosaLindl. under glasshouse conditions have been described.

  5. Tensile bond strength of hydroxyethyl methacrylate dentin bonding agent on dentin surface at various drying techniques

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    Kun Ismiyatin

    2010-06-01

    Full Text Available Background: There are several dentin surface drying techniques to provide a perfect resin penetration on dentin. There are two techniques which will be compared in this study. The first technique was by rubbing dentin surface gently using cotton pellet twice, this technique is called blot dry technique. The second technique is by air blowing dentin surface for one second and continued by rubbing dentin surface gently using moist cotton. Purpose: This experiment was aimed to examine the best dentin surface drying techniques after 37% phosphoric acid etching to obtain the optimum tensile bond strength between hydroxyethyl methacrylate (HEMA and dentin surface. Method: Bovine teeth was prepared flat to obtain the dentin surface and than was etched using 37% phosphoric acid for 15 seconds. After etching the dentin was cleaned using 20 cc plain water and dried with blot dry techniques (group I, or dried with air blow for one second (group II, or dried with air blow for one second, and continued with rubbing gently using moist cotton pellet (group III, and without any drying as control group (group IV. After these drying, the dentin surfaces were applied with resin dentin bonding agent and put into plunger facing the composite mould. The antagonist plunger was filled with composite resin. After 24 hours, therefore bond strength was measured using Autograph. Result: Data obtained was analyzed using One-Way ANOVA with 95% confidence level and continued with LSD test on p≤0.05. The result showed that the highest tensile bond strength was on group I, while the lowest on group IV. Group II and IV, III and IV, II and III did not show signigicant difference (p>0.05. Conclusion: Dentin surface drying techniques through gentle rubbing using cotton pellet twice (blot dry technique gave the greatest tensile bond strength.Latar belakang masalah: Tehnik pengeringan permukaan dentin agar resin dapat penetrasi dengan sempurna adalah dengan cara pengusapan secara

  6. Water evaporation from substrate tooth surface during dentin treatments.

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    Kusunoki, Mizuho; Itoh, Kazuo; Gokan, Yuka; Nagai, Yoshitaka; Tani, Chihiro; Hisamitsu, Hisashi

    2011-01-01

    The purpose of this study was to evaluate changes in the quantity of water evaporation from tooth surfaces. The amount of water evaporation was measured using Multi probe adapter MPA5 and Tewameter TM300 (Courage+Khazaka Electric GmbH, Köln, Germany) after acid etching and GM priming of enamel; and after EDTA conditioning and GM priming of dentin. The results indicated that the amount of water evaporation from the enamel surface was significantly less than that from the dentin. Acid etching did not affect the water evaporation from enamel, though GM priming significantly decreased the evaporation (83.48 ± 15.14% of that before priming). The evaporation from dentin was significantly increased by EDTA conditioning (131.38 ± 42.08% of that before conditioning) and significantly reduced by GM priming (80.26 ± 7.43% of that before priming). It was concluded that dentin priming reduced water evaporation from the dentin surface.

  7. Chemical treatment of the intra-canal dentin surface: a new approach to modify dentin hydrophobicity

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    Cesar GAITAN-FONSECA

    2013-01-01

    Full Text Available Objective This study evaluated the hydrophobicity of dentin surfaces that were modified through chemical silanization with octadecyltrichlorosilane (OTS. Material and Methods An in vitro experimental study was performed using 40 human permanent incisors that were divided into the following two groups: non-silanized and silanized. The specimens were pretreated and chemically modified with OTS. After the chemical modification, the dentin hydrophobicity was examined using a water contact angle measurement (WCA. The effectiveness of the modification of hydrophobicity was verified by the fluid permeability test (FPT. Results and Conclusions Statistically significant differences were found in the values of WCA and FPT between the two groups. After silanization, the hydrophobic intraradicular dentin surface exhibited in vitro properties that limit fluid penetration into the sealed root canal. This chemical treatment is a new approach for improving the sealing of the root canal system.

  8. EFFECT OF SURFACE CONDTIONINGON BOND STRENGTH TO ENAMEL AND DENTIN

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    M MOUSAVINASAB

    2002-09-01

    Full Text Available Introduction. Compoglass is a trade mark of dental compomers and because of its partially resinus structure, surface conditioning of dental surfaces is needed for a better bonding process. In this study, the effect of enamel and dentin conditioning procedure on shear bond strength (SBS of compoglass to tooth surfaces was studied. Methods. four groups each one including 11 sound premolars were chosen and their surfaces were prepared as following groups: group1, unconitioned dentin; group 2, dentin conditioning with phosphoric acid 35%; group 3, dentin conditioning with polyacrylic acid 20% group 4, unconditioning enamel; group 5, enamel conditioning with phosphoric acid 35%; and group 6, enamel conditioning with polyacrylic acid 20%. Compoglass was bonded to prepared surfaces and after fixation of the samples in acrylic molds, all samples were tested under shear force of instron testing machine at a rate of 1 mm/min speed. Results. The mean SBS obtained in these 6 groups were 6.207, 8.057, 10.146, 25.939 and 11.827 mpa. the mode of fracture also studied using a streomicroscope. Statistical analysis of the results showed that the maximum SBS obtained in group 5 and the lowest SBS about 6.207 mpa obtained in group 1. Despite increase in SBS group 2 and 3, there was no statistical differncies between group 1, 2 and 3. Discussion. Based on results of this study, conditioning of enamel and dentin surface due to improve SBS is recommeneded.

  9. In-Vitro Comparative Study of In-office and Home Bleaching Agents on Surface Micro-morphology of Enamel.

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    Fatima, Nazish

    2016-01-01

    To evaluate the effect of home-use bleaching agent containing 16% Carbamide Peroxide (CP) and in-office bleaching agent with 38% Hydrogen Peroxide (HP) on surface micro-morphology of enamel. An experimental study. The discs were prepared at Material Engineering Department of NED University of Engineering and Technology, Karachi, and surface morphology was analyzed at Centralized Science Laboratory of Karachi University, Pakistan. Duration of study was one year from January to December 2012. Forty five sound human third molar crowns, extracted for periodontal reason, were included in the study. Longitudinal sections were made using diamond disks (0.2 mm) under water lubrication to obtain enamel slabs measuring (3 mm x 3 mm). The slabs were embedded in polystyrene resin by using 2.0 cm diameter PVC molds, leaving the outer enamel surface uncovered by the resin. Ninety dental enamel slabs were prepared. The slabs were then randomly divided into 3 groups. Each group contained thirty specimens (n=30). Group 1 was kept in artificial saliva at 37°C in incubator (Memart, Germany) during whole experiment. Group 2 was treated with power whitening gel (White Smile 2011, Germany). Group 3 was treated with tooth whitening pen (White Smile 2011, Germany). The most central region or the region that was most representative of the entire surface area was used. The SEM (Jeol-Japan-JSM6380A, JAPAN) micrographs were examined to determine the type of surface presented. The enamel changes were classified as no or mild alteration, moderate alteration and severe altered surface. Regarding micro-morphology, the enamel surface of control groups showed smooth surface in general with some scattered clear scratches due to the polishing procedure. The specimens bleached in group 2 and group 3, represented areas of mild erosion. Bleaching with 38% Hydrogen Peroxide (HP) and 16% Carbamide Peroxide (CP) resulted in mild changes in surface micro-morphology of enamel.

  10. In-Vitro Comparative Study of In-office and Home Bleaching Agents on Surface Micro-morphology of Enamel

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    Fatima, N.

    2016-01-01

    Objective: To evaluate the effect of home-use bleaching agent containing 16 percent Carbamide Peroxide (CP) and in-office bleaching agent with 38 percentage Hydrogen Peroxide (HP) on surface micro-morphology of enamel. Study Design: An experimental study. Place and Duration of Study: The discs were prepared at Material Engineering Department of NED University of Engineering and Technology, Karachi, and surface morphology was analyzed at Centralized Science Laboratory of Karachi University, Pakistan. Duration of study was one year from January to December 2012. Methodology: Forty five sound human third molar crowns, extracted for periodontal reason, were included in the study. Longitudinal sections were made using diamond disks (0.2 mm) under water lubrication to obtain enamel slabs measuring (3 mm x 3 mm). The slabs were embedded in polystyrene resin by using 2.0 cm diameter PVC molds, leaving the outer enamel surface uncovered by the resin. Ninety dental enamel slabs were prepared. The slabs were then randomly divided into 3 groups. Each group contained thirty specimens (n=30). Group 1 was kept in artificial saliva at 37 degree C in incubator (Memart, Germany) during whole experiment. Group 2 was treated with power whitening gel (White Smile 2011, Germany). Group 3 was treated with tooth whitening pen (White Smile 2011, Germany). The most central region or the region that was most representative of the entire surface area was used. The SEM (Jeol-Japan-JSM6380A, JAPAN) micrographs were examined to determine the type of surface presented. The enamel changes were classified as no or mild alteration, moderate alteration and severe altered surface. Results: Regarding micro-morphology, the enamel surface of control groups showed smooth surface in general with some scattered clear scratches due to the polishing procedure. The specimens bleached in group 2 and group 3, represented areas of mild erosion. Conclusion: Bleaching with 38 percentage Hydrogen Peroxide (HP) and

  11. Morphological Analysis of Dentin Surface after Conditioning with Two Different methods: Chemical and Mechanical.

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    Rafael, Caroline Freitas; Quinelato, Valquíria; Morsch, Carolina Schaffer; DeDeus, Gustavo; Reis, Claudia Mendonca

    2016-01-01

    Alternative pretreatment strategies of dentin and adhesionare constantly being developed and studied with the goal of improving the adhesion of resin restorative materials with this tissue. The objectives of the present study were to evaluate the ability of airborne-particle abrasion (APA) with aluminum oxide on dentin to remove the smear layer and the effects produced on the dentin microstructure. The phosphoric acid (PA) was used for a comparison. For that, 20 human third molars were randomly allocated into two experimental groups, according to the dentin pretreatment method used: G1 (N = 10) - PA, G2 (N = 10) -APA. For dentin surface analyses, an environmental scanning electron microscope (ESEM) was employed to observe dentin surfaces before and after the procedures. Before pretreatment, the specimens of both groups were smear covered. After pretreatment, the G1 images revealed dentin tubule orifices opened, enlarged and some erosive effects. (G2) exposed tubule orifices without enlargement, but crack-like alterations were observed on the surfaces. In this way, APA with aluminum oxide was able to remove the smear layer. The influences of the dentin roughness on adhesion and the consequences on dentin integrity and hardness need further investigations. A good conditioning of the dentin before cementation is necessary in order to obtain a satisfactory rehabilitation in adhesive dentistry. So, it is necessary to know all methods to do it.

  12. Influences of the cold atmospheric plasma jet treatment on the properties of the demineralized dentin surfaces

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    Xiaoming, ZHU; Heng, GUO; Jianfeng, ZHOU; Xiaofei, ZHANG; Jian, CHEN; Jing, LI; Heping, LI; Jianguo, TAN

    2018-04-01

    Improvement of the bonding strength and durability between the dentin surface and the composite resin is a challenging job in dentistry. In this paper, a radio-frequency atmospheric-pressure glow discharge (RF-APGD) plasma jet is employed for the treatment of the acid-etched dentin surfaces used for the composite restoration. The properties of the plasma treated dentin surfaces and the resin-dentin interfaces are analyzed using the x-ray photoemission spectroscopy, contact angle goniometer, scanning electron microscope and microtensile tester. The experimental results show that, due to the abundant chemically reactive species existing in the RF-APGD plasma jet under a stable and low energy input operating mode, the contact angle of the plasma-treated dentin surfaces decreases to a stable level with the increase of the atomic percentage of oxygen in the specimens; the formation of the long resin tags in the scattered clusters and the hybrid layers at the resin-dentin interfaces significantly improve the bonding strength and durability. These results indicate that the RF-APGD plasma jet is an effective tool for modifying the chemical properties of the dentin surfaces, and for improving the immediate bonding strength and the durability of the resin-dentin bonding in dentistry.

  13. Micromorphological study (ultrastructure of lamina surface, seeds, ultrasculpture of pollen grains of Gladiolus L. species (Iridaceae Juss. of Ukrainian flora

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    Zhygalova Svitlana L.

    2014-12-01

    Full Text Available Micro-morphological characteristics of the four Gladiolus L. species of the Ukrainian flora (G. imbricatus L., G. italicus Mill., G. palustris Gaudin and G. tenuis M. Bieb. as regards leaves, seeds and pollens are presented with this investigation in a detailed way. An examination of the surface structure of the leaves, seeds and pollen grains of the Gladiolus species indicates that the characteristics of the ultrastructure of leaves and of pollen grains are not diagnostic for distinguishing species, but they could be important at genus level (leaves: features such as being amphistomatic, having the same quantity of immersed stomata on both surfaces and having a high stomata index, the presence and localisation of papillae, the shape of epidermal cells; pollen grains: monosulcate type with two operculums. However, the type of surface ultrastructure of the seed coat is a diagnostic feature as at genus level so for species. It can be mentioned that propose the use of features such as the shape and position of the cicatricle, the type of cuticle, the shape and boundaries of cells of testa, and the anticlinal cell walls as diagnostic features at genera level. The shape of seeds, the presence and disposition of wing, the level of the periclinal cell walls of the seed coat and types of relief are additional diagnostic features for distinguishing of Gladiolus species.

  14. Effect of enhanced UV-B radiation of adaxial leaf surface micromorphology and epicuticular wax biosynthesis of sugar maple

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    Gordon, D.C.; Percy, K.E.; Riding, R.T.

    1998-01-01

    Sugar maple (Acer saccharum [Marsh.]) seedlings were exposed to UV-B BE ranging from 0.61 kJ m -2 d -1 to 12.48 kJ m -2 d -1 . Increasing UV-B intensity was associated with changes in micromorphological characteristics of the adaxial leaf surface. In vivo incorporation of [1- 14 C] acetate into sugar maple adaxial leaf surface epicuticular wax indicated (p<0.05) a UV-B sensitivity threshold at or near 6.2 kJ m -2 d -1 . Exposure to dosages greater than 6.2 kJ m -2 d -1 resulted in a significant (p<0.05) decrease in wax biosynthesis. The proportion of [1- 14 C] acetate incorporated into each of the different epicuticular wax classes changed with increasing UV-B. Incorporation of [1- 14 C] acetate into alkyl esters decreased while incorporation into alkanes increased with increasing UV-B dose. The effects of enhanced UV-B dose recorded in this experiment may have implications for cuticle function. (author)

  15. Adhesive sealing of dentin surfaces in vitro: A review

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    Abu-Nawareg, Manar M; Zidan, Ahmed Z; Zhou, Jianfeng; Agee, Kelli; Chiba, Ayaka; Tagami, Jungi; Pashley, David H

    2016-01-01

    Purpose The purpose of this review is to describe the evolution of the use of dental adhesives to form a tight seal of freshly prepared dentin to protect the pulp from bacterial products, during the time between crown preparation and final cementum of full crowns. The evolution of these “immediate dentin sealants” follows the evolution of dental adhesives, in general. That is, they began with multiple-step, etch-and-rinse adhesives, and then switched to the use of simplified adhesives. Methods Literature was reviewed for evidence that bacteria or bacterial products diffusing across dentin can irritate pulpal tissues before and after smear layer removal. Smear layers can be solubilized by plaque organisms within 7–10 days if they are directly exposed to oral fluids. It is likely that smear layers covered by temporary restorations may last more than one month. As long as smear layers remain in place, they can partially seal dentin. Thus, many in vitro studies evaluating the sealing ability of adhesive resins use smear layer-covered dentin as a reference condition. Surprisingly, many adhesives do not seal dentin as well as do smear layers. Results Both in vitro and in vivo studies show that resin-covered dentin allows dentinal fluid to cross polymerized resins. The use of simplified single bottle adhesives to seal dentin was a step backwards. Currently, most authorities use either 3-step adhesives such as Scotchbond Multi-Purposea or OptiBond FLb or two-step self-etching primer adhesives, such as Clearfil SEc, Unifil Bondd or AdheSEe, respectfully. PMID:26846037

  16. Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration

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    Ritts, Andy Charles; Li, Hao; Yu, Qingsong; Xu, Changqi; Yao, Xiaomei; Hong, Liang; Wang, Yong

    2010-01-01

    The objective of this study is to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces for composite restoration. Extracted unerupted human third molars were used by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated by using a non-thermal atmospheric argon plasma brush for various durations. The molecular changes of the dentin surfaces were analyzed using FTIR/ATR and an increase in carbonyl groups on dentin surfaces was detected with plasma treated dentin. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were applied as directed. To evaluate the dentin/composite interfacial bonding, the teeth thus prepared were sectioned into micro-bars as the specimens for tensile test. Student Newman Keuls tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s plasma treatment. However, the bonding strength to plasma treated inner dentin did not show any improvement. It was found that plasma treatment of peripheral dentin surface up to 100 s gave an increase in interfacial bonding strength, while a prolong plasma treatment of dentin surfaces, e.g., 5 min treatments, showed a decrease in interfacial bonding strength. PMID:20831586

  17. Effect of Collagen Matrix Saturation on the Surface Free Energy of Dentin using Different Agents.

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    de Almeida, Leopoldina de Fátima Dantas; Souza, Samilly Evangelista; Sampaio, Aline Araújo; Cavalcanti, Yuri Wanderley; da Silva, Wander José; Del Bel Cur, Altair A; Hebling, Josimeri

    2015-07-01

    The surface free energy of conditioned-dentin is one of the factors that interfere with monomeric infiltration of the interfibrillar spaces. Saturation of the tooth matrix with different substances may modulate this energy and, consequently, the wettability of the dentin. To evaluate the influence of different substances used to saturate conditioned-dentin on surface free energy (SFE) of this substrate. Dentin blocks (4 × 7 × 1 mm, n = 6/ group), obtained from the roots of bovine incisors, were etched using phosphoric acid for 15 seconds, rinsed and gently dried. The surfaces were treated for 60 seconds with: ultra-purified water (H20-control); ethanol (EtOH), acetone (ACT), chlorhexidine (CHX), ethylenediaminetetraacetic acid (EDTA); or sodium hypochlorite (NaOCl). The tooth surfaces were once again dried with absorbent paper and prepared for SFE evaluation using three standards: water, formamide and bromonaphthalene. Analysis of variance (ANOVA) and Dunnet's tests (a = 0.05) were applied to the data. Ethylenediaminetetraacetic acid was the only substance that caused a change to the contact angle for the standards water and formamide, while only EtOH influenced the angles formed between formamide and the dentin surface. None of the substances exerted a significant effect for bromonaphtha-lene. In comparison to the control, only EDTA and NaOCl altered both polar components of the SFE. Total SFE was increased by saturation of the collagen matrix by EDTA and reduced when NaOCl was used. Saturation of the collagen matrix by EDTA and EtOH changed the surface free energy of the dentin. In addition, the use of NaOCl negatively interfered with the properties evaluated. The increase of surface free energy and wettability of the dentin surface would allow higher penetration of the the adhesive system, which would be of importance to the clinical success of resin-dentin union.

  18. The effect of dentine surface preparation and reduced application time of adhesive on bonding strength.

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    Saikaew, Pipop; Chowdhury, A F M Almas; Fukuyama, Mai; Kakuda, Shinichi; Carvalho, Ricardo M; Sano, Hidehiko

    2016-04-01

    This study evaluated the effects of surface preparation and the application time of adhesives on the resin-dentine bond strengths with universal adhesives. Sixty molars were cut to exposed mid-coronal dentine and divided into 12 groups (n=5) based on three factors; (1) adhesive: G-Premio Bond (GP, GC Corp., Tokyo, Japan), Clearfil Universal Bond (CU, Kuraray Noritake Dental Inc., Okayama, Japan) and Scotchbond Universal Adhesive (SB, 3M ESPE, St. Paul, MN, USA); (2) smear layer preparation: SiC paper ground dentine or bur-cut dentine; (3) application time: shortened time or as manufacturer's instruction. Fifteen resin-dentine sticks per group were processed for microtensile bond strength test (μTBS) according to non-trimming technique (1mm(2)) after storage in distilled water (37 °C) for 24h. Data were analyzed by three-way ANOVA and Dunnett T3 tests (α=0.05). Fractured surfaces were observed under scanning electron microscope (SEM). Another 12 teeth were prepared and cut into slices for SEM examination of bonded interfaces. μTBS were higher when bonded to SiC-ground dentine according to manufacturer's instruction. Bonding to bur-cut dentine resulted in significantly lower μTBS (padhesive resin interface. This was more pronounced when adhesives were bonded with a reduced application time and on bur cut dentine. The performance of universal adhesives can be compromised on bur cut dentine and when applied with a reduced application time. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Ultrastructural investigation of root canal dentine surface after application of active ultrasonic method

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    Mitić Aleksandar

    2008-01-01

    Full Text Available INTRODUCTION The basic work principle of all ultrasonic techniques is the piezoelectric effect of producing high frequency ultrasounds of small length, which are transmitted over the endodontic extensions or canal instruments into the root canal. When in contact with the tissue, ultrasonic vibrations are converted into mechanical oscillations. Ultrasonic waves and the obtained oscillations along with the synergic effect of irrigation bring about the elimination of smear layer from the root canal walls. OBJECTIVE The aim of the study was to ultrastucturally examine the effect of smear layer removal from the walls of canals by the application of the active ultrasonic method without irrigation, that is by the application of ultrasound and irrigation using distilled water and 2.5% NaOCl. METHOD The investigation comprised 35 single-canal, extracted human teeth. After removal of the root canal content, experimental samples were divided into three groups. According to the procedure required, the first group was treated by ultrasound without irrigation; the second one by ultrasound with irrigation using distilled water; and the third group was treated by ultrasound and irrigation using 2.5% NaOCl solution. The control samples were treated by machine rotating instruments (Pro-File and were rinsed by distilled water. RESULTS The obtained results showed that the ultrasonic treatment of the root canal without irrigation did not remove the smear layer. The dentine canals are masked, and big dentine particles are scattered on the intertubular dentine. The ultrasonic treatment by using irrigation with distilled water provides cleaner dentine walls and open dentine tubules but with smaller particles on the intertubular dentine. The ultrasound treatment by using irrigation with 2.5% NaOCl solution provides a clean intertubular dentine surface without a smear layer and clearly open dentine tubules. CONCLUSION Instrumentation of the root canal by application of

  20. Effect of Enamel and Dentin Surface Treatment on the Self-Adhesive Resin Cement Bond Strength.

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    Mushashe, Amanda Mahmmad; Gonzaga, Carla Castiglia; Cunha, Leonardo Fernandes da; Furuse, Adilson Yoshio; Moro, Alexandre; Correr, Gisele Maria

    2016-01-01

    The aim of this study was to evaluate the effect of enamel and dentin surface treatment on the micro-shear bond strength of self-adhesive cement. Seventy-two extracted third molars had their crowns embedded in acrylic resin and worn to obtain a flat enamel or dentin surface. The enamel and dentin specimens were randomly assigned to 8 groups (n=12) that were based on surface treatment (11.5% polyacrylic acid solution or no treatment), substrate condition (wet or dry) and storage period (1 day or 90 days), and treated accordingly. Cylinders (1 × 1 mm) were fabricated using self-adhesive resin cement (RelyX U200) following the manufacturer's instructions. The specimens were stored in distilled water at 37 °C for either 1 day or 90 days and subjected to micro-shear bond strength test (EMIC DL 2000 at 0.5 mm/min). After this, the failure type of the specimens was determined. Data were subjected to statistical analysis (a=0.05). According to the results, the 11.5% polyacrylic acid application decreased the bond strength in both enamel and dentin samples. The moist groups showed higher bond strength than the dry ones, regardless of the substrate and surface treatment. Storage period did not influence bond strength. In conclusion, surface treatment with 11.5% polyacrylic acid and absence of moisture decreased the bond strength of the resin-cement (RelyU200), regardless of the storage period.

  1. Effect of LASER Irradiation on the Shear Bond Strength of Zirconia Ceramic Surface to Dentin

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    Sima Shahabi

    2012-09-01

    Full Text Available Background and Aims: Reliable bonding between tooth substrate and zirconia-based ceramic restorations is always of great importance. The laser might be useful for treatment of ceramic surfaces. The aim of the present study was to investigate the effect of laser irradiation on the shear bond strength of zirconia ceramic surface to dentin. Materials and Methods: In this experimental in vitro study, 40 Cercon zirconia ceramic blocks were fabricated. The surface treatment was performed using sandblasting with 50-micrometer Al2O3, CO2 laser, or Nd:YAG laser in each test groups. After that, the specimens were cemented to human dentin with resin cement. The shear bond strength of ceramics to dentin was determined and failure mode of each specimen was analyzed by stereo-microscope and SEM investigations. The data were statistically analyzed by one-way analysis of variance and Tukey multiple comparisons. The surface morphology of one specimen from each group was investigated under SEM. Results: The mean shear bond strength of zirconia ceramic to dentin was 7.79±3.03, 9.85±4.69, 14.92±4.48 MPa for CO2 irradiated, Nd:YAG irradiated, and sandblasted specimens, respectively. Significant differences were noted between CO2 (P=0.001 and Nd:YAG laser (P=0.017 irradiated specimens with sandblasted specimens. No significant differences were observed between two laser methods (P=0.47. The mode of bond failure was predominantly adhesive in test groups (CO2 irradiated specimens: 75%, Nd:YAG irradiated: 66.7%, and sandblasting: 41.7%. Conclusion: Under the limitations of the present study, surface treatment of zirconia ceramics using CO2 and Nd:YAG lasers was not able to produce adequate bond strength with dentin surfaces in comparison to sandblasting technique. Therefore, the use of lasers with the mentioned parameters may not be recommended for the surface treatment of Cercon ceramics.

  2. Bonding of the Polymer Polyetheretherketone (PEEK) to Human Dentin: Effect of Surface Treatments.

    Science.gov (United States)

    Rocha, Regina Furbino Villefort; Anami, Lilian Costa; Campos, Tiago Moreira Bastos; Melo, Renata Marques de; Souza, Rodrigo Othávio de Assunção E; Bottino, Marco Antonio

    2016-01-01

    Polyetheretherketone (PEEK) is a material suitable for frameworks of fixed dental prostheses. The effect of different surface treatments on the bond strength of PEEK bonded to human dentin was evaluated. One hundred PEEK cylinders (3 mm×3 mm) were divided into five groups according to surface treatment: silica coating, sandblasting with 45 μm Al2O3 particles, etching with 98% sulfuric acid for 5, 30 and for 60 s. These cylinders were luted with resin cement onto 50 human molars. First, each tooth was embedded in epoxy resin and the buccal dentin surface was exposed. Then, two delimited dentin areas (Æ:3 mm) per tooth were etched with 35% phosphoric acid and bonded with a two-step self-priming adhesive system. After the luting procedure the specimens were stored in water (24 h/37 °C). Shear bond strength (SBS) was tested using a universal testing machine (crosshead speed 0.5 mm/min; load cell 50 kgf) and failure types were assessed. Stress data (MPa) were analyzed using the Kruskal-Wallis test. Comparison of the proportions of different failure types was performed using the Bonferroni method (pPEEK, resin cement and dentin.

  3. Bond strength of resin modified glass ionomer cement to primary dentin after cutting with different bur types and dentin conditioning

    Directory of Open Access Journals (Sweden)

    Rebeca Di Nicoló

    2007-10-01

    Full Text Available The aim of this in vitro study was to evaluate the effect of different bur types and acid etching protocols on the shear bond strength (SBS of a resin modified glass ionomer cement (RM-GIC to primary dentin. Forty-eight clinically sound human primary molars were selected and randomly assigned to four groups (n=12. In G1, the lingual surface of the teeth was cut with a carbide bur until a 2.0-mm-diameter dentin area was exposed, followed by the application of RM-GIC (Vitremer - 3M/ESPE prepared according to the manufacturer's instructions. The specimens of G2, received the same treatment of G1, however the dentin was conditioned with phosphoric acid. In groups G3 and G4 the same procedures of G1 and G2 were conducted respectively, nevertheless dentin cutting was made with a diamond bur. The specimens were stored in distilled water at 37ºC for 24h, and then tested in a universal testing machine. SBS. data were submitted to 2-way ANOVA (= 5% and indicated that SBS values of RM-GIC bonded to primary dentin cut with different burs were not statistically different, but the specimens that were conditioned with phosphoric acid presented SBS values significantly higher that those without conditioning. To observe micromorphologic characteristics of the effects of dentin surface cut by diamond or carbide rotary instruments and conditioners treatment, some specimens were examined by scanning electron microscopy. Smear layer was present in all specimens regardless of the type of rotary instrument used for dentin cutting, and specimens etched with phosphoric acid presented more effective removal of smear layer. It was concluded that SBS of a RM-GIC to primary dentin was affected by the acid conditioning but the bur type had no influence.

  4. Influence of temporary cement contamination on the surface free energy and dentine bond strength of self-adhesive cements.

    Science.gov (United States)

    Takimoto, Masayuki; Ishii, Ryo; Iino, Masayoshi; Shimizu, Yusuke; Tsujimoto, Akimasa; Takamizawa, Toshiki; Ando, Susumu; Miyazaki, Masashi

    2012-02-01

    The surface free energy and dentine bond strength of self-adhesive cements were examined after the removal of temporary cements. The labial dentine surfaces of bovine mandibular incisors were wet ground with #600-grit SiC paper. Acrylic resin blocks were luted to the prepared dentine surfaces using HY Bond Temporary Cement Hard (HY), IP Temp Cement (IP), Fuji TEMP (FT) or Freegenol Temporary Cement (TC), and stored for 1 week. After removal of the temporary cements with an ultrasonic tip, the contact angle values of five specimens per test group were determined for the three test liquids, and the surface-energy parameters of the dentine surfaces were calculated. The dentine bond strengths of the self-adhesive cements were measured after removal of the temporary cements in a shear mode at a crosshead speed of 1.0mm/min. The data were subjected to one-way analysis of variance (ANOVA) followed by Tukey's HSD test. For all surfaces, the value of the estimated surface tension component γ(S)(d) (dispersion) was relatively constant at 41.7-43.3 mJm(-2). After removal of the temporary cements, the value of the γ(S)(h) (hydrogen-bonding) component decreased, particularly with FT and TC. The dentine bond strength of the self-adhesive cements was significantly higher for those without temporary cement contamination (8.2-10.6 MPa) than for those with temporary cement contamination (4.3-7.1 MPa). The γ(S) values decreased due to the decrease of γ(S)(h) values for the temporary cement-contaminated dentine. Contamination with temporary cements led to lower dentine bond strength. The presence of temporary cement interferes with the bonding performance of self-adhesive cements to dentine. Care should be taken in the methods of removal of temporary cement when using self-adhesive cements. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Shear bond strength of two bonding systems on dentin surfaces prepared with Er:YAG laser

    International Nuclear Information System (INIS)

    Dall'Magro, Eduardo

    2001-01-01

    The purpose of this study was to examine the shear bond strength of two bonding dentin systems, one 'one step' (Single Bond - 3M) and one 'self-etching' (Prompt-L-ESPE), when applied on dentin surfaces prepared with Er:YAG laser (2,94μm) that underwent ar not, acid etched. Forty one human molars just extracted were selected and after the cut with diamond disc and included in acrylic resin, resulting in 81 specimens (hemi crowns). After, the specimens were divided in one group treated with sand paper and another two groups treated with Er:YAG laser with 200 mJ and 250 mJ of energy and 2 Hz of frequency. Next, the prepared surfaces received three treatments with following application: 1) acid + Single Bond + Z 250 resin, 2) prompt-L-Pop + Z 250 resin, and 3) acid without, Single Bond + Z 250 resin. The Z 250 resin was applied and photopolymerized in increments on a Teflon matrix that belonged to an apparatus called 'Assembly Apparatus' machine producing cylinders of 3,5 mm of diameter and 5 mm of height. After these specimens were submitted to thermo cycling during 1 minute the 55 deg C and during 1 minute with 5 deg C with a total of 500 cycles for specimen, and the measures of shear bond strength were abstained using EMIC model DL 2000 rehearsed machine, with speed of 0,5 mm/min, measuring the final rupture tension (Mpa). The results showed an statistic superiority of 5% of probability level in dentin flattened with sandpaper and with laser using 200 mJ of energy with aspect to the ones flattened with laser using 250 mJ of energy. It was observed that using 'Single Bond' bonding dentin system the marks were statistically superior at 5% of probability with reference to the use of the Prompt-L-Pop adhesive system. So, it was concluded that Er:YAG Laser with 200 mJ of energy produced similar dentin cavity prepare than sandpaper and Single Bond seemed the best bonding agent system between restorative material and dentin. (author)

  6. In Vitro assessment of dentin erosion after immersion in acidic beverages: surface profile analysis and energy-dispersive X-ray fluorescence spectrometry study

    OpenAIRE

    Caneppele, Taciana Marco Ferraz; Jeronymo, Raffaela Di Iorio; Di Nicoló, Rebeca; Araújo, Maria Amélia Máximo de; Soares, Luís Eduardo Silva

    2012-01-01

    The aim of this study was to investigate the effects of some acidic drinks on dentin erosion, using methods of surface profile (SP) analysis and energy-dispersive X-ray fluorescence spectrometry (EDXRF). One hundred standardized dentin slabs obtained from bovine incisor roots were used. Dentin slabs measuring 5x5 mm were ground flat, polished and half of each specimen surface was protected with nail polish. For 60 min, the dentin surfaces were immersed in 50 mL of 5 different drinks (Gatorade...

  7. Bond strength of resin cement to dentin and to surface-treated posts of titanium alloy, glass fiber, and zirconia

    DEFF Research Database (Denmark)

    Sahafi, Alireza; Peutzfeldt, Anne; Asmussen, Erik

    2003-01-01

    PURPOSE: To determine the effect of surface treatments on bond strength of two resin cements (ParaPost Cement and Panavia F) to posts of titanium alloy (ParaPost XH), glass fiber (ParaPost Fiber White), and zirconia (Cerapost), and to dentin. MATERIALS AND METHODS: After embedding, planar surfaces...... of posts (n = 9 to 14) and human dentin (n = 10) were obtained by grinding. The posts received one of three surface treatments: 1. roughening (sandblasting, hydrofluoric acid etching), 2. application of primer (Alloy Primer, Metalprimer II, silane), or 3. roughening followed by application of primer...

  8. Changing of micromorphology of silicon-on-sapphire epitaxial layer surface at irradiation by subthreshold energy X-radiation

    CERN Document Server

    Kiselev, A N; Skupov, V D; Filatov, D O

    2001-01-01

    The morphology of silicon-on-sapphire epitaxial layer surface after pulse irradiation by the X-rays with the energy of <= 140 keV is studied. The study on the irradiated material surface is carried out by the methods of the atomic force microscopy and ellipsometry. The average roughness value after irradiation constitutes 7 nm. The change in the films surface microrelief occurs due to reconstruction of their dislocation structure under the action of elastic waves, originating in the X radiation

  9. The Effect of Hydrofluoric Acid Etching Duration on the Surface Micromorphology, Roughness, and Wettability of Dental Ceramics

    Science.gov (United States)

    Ramakrishnaiah, Ravikumar; Alkheraif, Abdulaziz A.; Divakar, Darshan Devang; Matinlinna, Jukka P.; Vallittu, Pekka K.

    2016-01-01

    The current laboratory study is evaluating the effect of hydrofluoric acid etching duration on the surface characteristics of five silica-based glass ceramics. Changes in the pore pattern, crystal structure, roughness, and wettability were compared and evaluated. Seventy-five rectangularly shaped specimens were cut from each material (IPS e-max™, Dentsply Celtra™, Vita Suprinity™, Vita mark II™, and Vita Suprinity FC™); the sectioned samples were finished, polished, and ultrasonically cleaned. Specimens were randomly assigned into study groups: control (no etching) and four experimental groups (20, 40, 80 and 160 s of etching). The etched surfaces’ microstructure including crystal structure, pore pattern, pore depth, and pore width was studied under a scanning electron microscope, and the surface roughness and wettability were analyzed using a non-contact surface profilometer and a contact angle measuring device, respectively. The results were statistically analyzed using one-way analysis of variance (ANOVA) and the post hoc Tukey’s test. The results showed a significant change in the pore number, pore pattern, crystal structure, surface roughness, and wettability with increased etching duration. Etching for a short time resulted in small pores, and etching for longer times resulted in wider, irregular grooves. A significant increase in the surface roughness and wettability was observed with an increase in the etching duration. The findings also suggested a strong association between the surface roughness and wettability. PMID:27240353

  10. Effect of different surface treatments on adhesion of In-Ceram Zirconia to enamel and dentin substrates.

    Science.gov (United States)

    Saker, Samah; Ibrahim, Fatma; Ozcan, Mutlu

    2013-08-01

    Resin bonding of In-Ceram Zirconia (ICZ) ceramics is still a challenge, especially for minimally invasive applications. This study evaluated the adhesion of ICZ to enamel and dentin after different surface treatments of the ceramic. ICZ ceramic specimens (diameter: 6 mm; thickness: 2 mm) (N = 100) were fabricated following the manufacturer's instructions and randomly assigned to 5 groups (n = 20), according to the surface treatment methods applied. The groups were as follows: group C: no treatment; group SB: sandblasting; group SCS-S: CoJet+silane; group SCS-P: CoJet+Alloy Primer; group GE-S: glaze+ hydrofluoric acid etching (9.6%) for 60 s+silane. Each group was randomly divided into two subgroups to be bonded to either enamel or dentin (n = 10 per group) using MDP-based resin cement (Panavia F2.0). All the specimens were subjected to thermocycling (5000x, 5°C-55°C). The specimens were mounted in a universal testing machine and tensile force was applied to the ceramic/cement interface until failure occurred (1 mm/min). After evaluating all the debonded specimens under SEM, the failure types were defined as either "adhesive" with no cement left on the ceramic surface (score 0) or "mixed" with less than 1/2 of the cement left adhered to the surface with no cohesive failure of the substrate (score 1). The data were statistically evaluated using 2-way ANOVA and Tukey's tests (α = 0.05). The highest tensile bond strength for the enamel surfaces was obtained in group GE-S (18.1 ± 2 MPa) and the lowest in group SB (7.1 ± 1.4 MPa). Regarding dentin, group CSC-P showed the highest (12 ± 1.3 MPa) and SB the lowest tensile bond strength (5.7 ± 0.4 MPa). Groups SB, CSC-S, CSC-P, and GE-S did not show significant differences between the different surface treatments on either enamel or dentin surfaces (p enamel and dentin substrates (p enamel substrates, exclusively adhesive failures from ICZ (score 0) were found, on dentin exclusively mixed failures were observed (score

  11. Modification of dentin surface to enamel-like structure: A potential strategy for improving dentin bonding durability, desensitizing and self-repairing

    Directory of Open Access Journals (Sweden)

    Hongye Yang

    2014-01-01

    Full Text Available Introduction: Current theories of dentin bonding are based on the concept of "hybrid layer". However, the histological complexity of dentin, as well as the vulnerability of the hybrid layer, goes against the long-term effect of dentin bonding. At the same time, post-operative sensitivity is more likely to occur after traditional adhesive restoration. The Hypothesis: Compared to dentin bonding, enamel bonding exhibits a more optimal immediate and long-term performance, owing to its higher degree of mineralization, well-arranged enamel crystals and the porous structure after etching. Moreover, "enamel hypersensitivity" is never going to happen due to the lack of tubules existing in dentin. In light of this phenomenon, we brought up the concept and the proposal method to form an "enamel-like" dentin, simulating enamel structure to achieve satisfying durability of dentin bonding and obtain good performance for preventing post-operative sensitivity. With the application of mesoporous silicon bi-directionally binding to hydroxyapatite of dentin itself and hydroxyapatite nanorods synthetized in vitro, we may be able to form an enamel-like "functional layer" via ion-regulating self-assembly. Evaluation of Hypothesis: This paper explains how to achieve dentin enamel-like modification by chemical methods, especially, details the strategies and possible mechanisms of the hypothesis. Validation of the hypothesis is more likely to eliminate the adverse effect of dentinal fluid, improve long-term performance of dentin bonding, offer strategies for desensitizing treatment and self-repairing carious-affected dentin, and furthermore, provide the possibility to introduce new theories of dentin bonding.

  12. Effect of a 5000 ppm fluoride toothpaste and a 250 ppm fluoride mouth rinse on the demineralisation of dentin surfaces.

    Science.gov (United States)

    Bizhang, Mozhgan; Chun, Yong-Hee P; Winterfeld, Mai-Trinh; Altenburger, Markus J; Raab, Wolfgang H M; Zimmer, Stefan

    2009-07-23

    The purpose of this study was to test the null hypothesis that there is no difference between the effect of (1) a 5000 ppm fluoride toothpaste, and (2) a 250 ppm fluoride mouth rinse on demineralized human dentin surfaces, against the alternative hypothesis of a difference. Dentin specimens were obtained from the cervical regions of 45 extracted human third molars. Half the surface of each specimen was sealed with a self-etching adhesive system and served as the reference surface. The dentin specimens were randomly assigned to one of the three groups, 5000 ppm fluoride toothpaste (Duraphat), 250 ppm fluoride mouth rinse (Meridol) and distilled water (negative control).An intraoral appliance was made for one volunteer. In each test cycle, 15 specimens were inserted in the appliance and worn for 24 hours a day, over a period of three weeks.Once daily, the appliance was immersed in the agent being tested; either toothpaste slurry, mouth rinse or distilled water for 60 seconds.Demineralization was assessed in terms of lesion depth (microm) and mineral loss (vol. % x microm) by transversal microradiography. Data analysis was accomplished using Kolmogorov-Smirnov test and ANOVA (SPSS 12.0).Statistically significant differences for mineral loss and lesion depth were found between the toothpaste and the mouth rinse as well as between the toothpaste and the control group, but not between the mouth rinse and the control group. Within the limitations of this study, the results suggest that treatment of demineralised dentin with a toothpaste containing 5000 ppm fluoride may considerably reduce mineral loss and lesion depth on exposed dentin.

  13. Regulation of Reactionary Dentine Formation.

    Science.gov (United States)

    Neves, V C M; Sharpe, P T

    2018-04-01

    During the treatment of dental caries that has not penetrated the tooth pulp, maintenance of as much unaffected dentine as possible is a major goal during the physical removal of decayed mineral. Damage to dentine leads to release of fossilized factors (transforming growth factor-β [TGF-β] and bone morphogenic protein [BMP]) in the dentine that are believed to stimulate odontoblasts to secrete new "tertiary" dentine (reactionary dentine). This is formed on the pulpal surface of existing dentine and rethickens the dentine. We have previously shown that activation of Wnt/β-catenin signaling is pivotal for tooth repair in exposed pulp injury, and the pathway can be activated by small-molecule GSK-3 antagonists, resulting in enhanced reparative dentine formation. Here, we use a nonexposed pulp injury model to investigate the mechanisms of reactionary dentine formation in vivo, using small molecules to modulate the Wnt/β-catenin, TGF-β, and BMP pathways. We found that a local increase of Wnt activation at the injury site enhances reactionary dentine secretion. In addition, inhibition of TGF-β, BMP, or Wnt pathways does not impede reactionary dentine formation, although inhibition of TGF-β and/or BMP signaling does result in more disorganized, nontubular reactionary dentine. This suggests that Wnt/β-catenin signaling plays no major role in the formation of reactionary dentine, but in common with reparative dentine formation, exogenous elevation of Wnt/β-catenin signaling can enhance tertiary dentine formation. Release of latent TGF-β or BMPs from dentine is not required for the deposition of mineral to form reactionary dentine but does play a role in its organization.

  14. Microtensile bond strength of etch-and-rinse and self-etching adhesives to intrapulpal dentin after endodontic irrigation and setting of root canal sealer.

    Science.gov (United States)

    Wattanawongpitak, Nipaporn; Nakajima, Masatoshi; Ikeda, Masaomi; Foxton, Richard M; Tagami, Junji

    2009-02-01

    To evaluate the effect of endodontic irrigation regimens and calcium hydroxide root canal sealer (Sealapex) on the microtensile bond strengths (muTBS) of dual-curing resin composite (Clearfil DC Core Automix) to the intrapulpal dentin. Forty standardized coronal-half root canal dentin specimens obtained from human premolars were divided into 4 groups: group A, no treatment (control); group B, Sealapex; group C, NaOCl/Sealapex; group D, EDTA/NaOCl/Sealapex. After 7 days of storage in 100% relative humidity, Sealapex was removed. Dentin surfaces were bonded with adhesives, either etch-and-rinse (Single Bond) or self-etching (Clearfil SE Bond), and built up with resin composite. The bonded specimens were trimmed into an hourglass shape with a 1-mm2 cross-sectional area for microtensile testing (n = 20). The muTBS to intrapulpal dentin was analyzed using two-way ANOVA and Dunnett's TC test. Two teeth of each group were prepared for micromorphological analysis of dentin surface. The root canal sealer with or without endodontic irrigation significantly affected the bond strengths of resin composite to intrapulpal dentin compared with the control group (p 0.05). The dentin surface was covered with a mud-like material after sealer application for 7 days. The root canal sealer reduced the muTBS of dual-curing resin composite with etch-and-rinse and self-etching adhesive systems to intrapulpal dentin. Treatment with EDTA followed by NaOCI prior to obturation caused an additional reduction in muTBS of both adhesive systems to intrapulpal dentin.

  15. Effects of air polishing and an amino acid buffered hypochlorite solution to dentin surfaces and periodontal ligament cell survival, attachment, and spreading.

    Science.gov (United States)

    Schmidlin, Patrick R; Fujioka-Kobayashi, Masako; Mueller, Heinz-Dieter; Sculean, Anton; Lussi, Adrian; Miron, Richard J

    2017-06-01

    The aim of this study is to examine morphological changes of dentin surfaces following air polishing or amino acid buffered hypochlorite solution application and to assess their influence on periodontal ligament (PDL) cell survival, attachment, and spreading to dentin discs in vitro. Bovine dentin discs were treated with either (i) Classic, (ii) Plus, or (iii) Perio powder (EMS). Furthermore, Perisolv® a hypochlorite solution buffered with various amino acids was investigated. Untreated dentin discs served as controls. Morphological changes to dentin discs were assessed using scanning electron microscopy (SEM). Human PDL cells were seeded onto the respectively treated discs, and samples were then investigated for PDL cell survival, attachment, and spreading using a live/dead assay, adhesion assay, and SEM imaging, respectively. Both control and Perisolv®-rinsed dentin discs demonstrated smooth surfaces at low and high magnifications. The Classic powders demonstrated the thickest coating followed by the Powder Plus. The Perio powder demonstrated marked alterations of dentin discs by revealing the potential to open dentinal tubules even before rinsing. Seeding of PDL cells demonstrated an almost 100 % survival rate on all samples demonstrating very high biocompatibility for all materials. Significantly higher PDL cell numbers were observed on samples treated with the Perio powder and the Perisolv® solution (approximately 40 % more cells; p air polishing or application with Perisolv®. Future in vitro and animal testing is necessary to further characterize the beneficial effects of either system in a clinical setting. The use of air polishing or application with Perisolv amino acid buffered hypochlorite solution was effective in treating root surfaces and allowed for near 100 % PDL cell survival, attachment, and spreading onto all root surfaces.

  16. Leaf micromorphology of some Phyllanthus L. species (Phyllanthaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Solihani, N. S., E-mail: noorsolihani@gmail.com; Noraini, T., E-mail: norainitalip@gmail.com [School of Environmental and Natural Resource Sciences Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Azahana, A., E-mail: bell-azahana@yahoo.com [Department of Plant Science, Kulliyyah of Science, International Islamic University Malaysia, Kuantan Campus, Kuantan, Pahang (Malaysia); Nordahlia, A. S., E-mail: nordahlia@frim.gov.my [Forest Research Institute of Malaysia, 52109 Kepong, Selangor (Malaysia)

    2015-09-25

    Comparative leaf micromorphological study was conducted of five chosen Phyllanthus L. (Phyllanthaceae) species, namely P. acidus L., P. elegans Wall. ex Müll. Arg., P. emblica L., P. urinaria L. and P. pulcher Wall. ex Müll. Arg. The objective of this study is to identify the leaf micromorphological characteristics that can be used in species identification. The procedures involve examination under scanning electron microscope. Findings of this study have demonstrated variations in the leaf micromorphological characteristics such as in the types of waxes present on adaxial and abaxial epidermis surfaces, in the stomata and types of trichome. Common character present in all species studied are the presence of a thin film layer and buttress-like waxes on epidermal leaf surfaces. Diagnostics characters found in this study are the presence of papilla in P. elegens, amphistomatic stomata in P. urinaria and flaky waxes in P. pulcher. The result of this study has shown that leaf micromorphological characters have some taxonomic significance and can be used in identification of species in the genus Phyllanthus.

  17. Periodontal ligament stem/progenitor cells with protein-releasing scaffolds for cementum formation and integration on dentin surface.

    Science.gov (United States)

    Cho, Hankyu; Tarafder, Solaiman; Fogge, Michael; Kao, Kristy; Lee, Chang H

    2016-11-01

    Purpose/Aim: Cementogenesis is a critical step in periodontal tissue regeneration given the essential role of cementum in anchoring teeth to the alveolar bone. This study is designed to achieve integrated cementum formation on the root surfaces of human teeth using growth factor-releasing scaffolds with periodontal ligament stem/progenitor cells (PDLSCs). Human PDLSCs were sorted by CD146 expression, and characterized using CFU-F assay and induced multi-lineage differentiation. Polycaprolactone scaffolds were fabricated using 3D printing, embedded with poly(lactic-co-glycolic acids) (PLGA) microspheres encapsulating connective tissue growth factor (CTGF), bone morphogenetic protein-2 (BMP-2), or bone morphogenetic protein-7 (BMP-7). After removing cementum on human tooth roots, PDLSC-seeded scaffolds were placed on the exposed dentin surface. After 6-week culture with cementogenic/osteogenic medium, cementum formation and integration were evaluated by histomorphometric analysis, immunofluorescence, and qRT-PCR. Periodontal ligament (PDL) cells sorted by CD146 and single-cell clones show a superior clonogenecity and multipotency as compared with heterogeneous populations. After 6 weeks, all the growth factor-delivered groups showed resurfacing of dentin with a newly formed cementum-like layer as compared with control. BMP-2 and BMP-7 showed de novo formation of tissue layers significantly thicker than all the other groups, whereas CTGF and BMP-7 resulted in significantly improved integration on the dentin surface. The de novo mineralized tissue layer seen in BMP-7-treated samples expressed cementum matrix protein 1 (CEMP1). Consistently, BMP-7 showed a significant increase in CEMP1 mRNA expression. Our findings represent important progress in stem cell-based cementum regeneration as an essential part of periodontium regeneration.

  18. Micromorphological studies on petals of spiraea l. species (rosaceae) from pakistan

    International Nuclear Information System (INIS)

    Omer, S.A.

    2017-01-01

    Epidermal micromorphology of petals of 10 species of Spiraea L. of the family Rosaceae from Pakistan has been examined with Scanning Electron Microscope (SEM). Micromorphological attributes observed in petals and their reliability as a taxonomic marker is discussed. The epidermal cells exhibit definite geometrical patterns, where cell wall boundaries are more or less elevated and cell surface generally marked with striae. Stomata are completely absent. (author)

  19. Morphological Alterations of the Surfaces of Enamel and Dentin of Deciduous Teeth Irradiated with Nd:YAG, C0(2)and Diode Lasers

    OpenAIRE

    Souza, Mónica Rodrigues de; Watanabe, Ii-Sei; Azevedo, Luciane H; Tanji, Edgar Y

    2009-01-01

    In this work, we studied the effects of C0(2), Nd:YAG and diode lasers on the enamel and dentin of deciduous human teeth. After the irradiations, the samples were duly prepared and set up on metallic bases, covered with gold and examined in the scanning electron microscope. The results showed that the irradiation with the C0(2) mode locked laser with 1.0 W power caused melting and irregularities with small cavities on the surface of the enamel. The irradiated area on the dentin surface appear...

  20. Features of micromorphological structure of medicinal hyssop

    Directory of Open Access Journals (Sweden)

    Lyudmyla A. Kotyuk

    2016-06-01

    Full Text Available Micromorphological peculiarities of the structure of vegetative and generative organs of Hyssopus officinalis were analyzed. The epidermis of H. officinalis reveals diacyctic stomata and external outgrowths: glandular and covering trichomes, as well as peltate essential oil glands. Capitate and bent indumentary (covering trichomes occur on the stem, while on the leaves peltate glands, conical and bent uni- and multicellular trichomes were observed. On the calyx, in the midrib region, there are peltate glands while the ribs are densely covered with indumentary and glandular trichomes. The corolla’s adaxial surface is covered with long indumentary trichomes, with sparse peltate glands occurring on the margins. The highest density of essential oil peltate glands is found on the adaxial surface of the calyx upper lip (15.8±2.54 pcs./mm2 and on the leaf abaxial surface (13.6±2.40 pcs./mm2. Glands with the largest diameter (47.82±2.82 μm are located on the leaf adaxial surface.

  1. Evaluating the effect of dentin surface pretreatment on the static contact angle of a drop of a bonding agent: an in vitro study

    Directory of Open Access Journals (Sweden)

    Mehrdad Barekatain

    2016-03-01

    Full Text Available Introduction: The aim of this study was to investigate the effect of dentinal pretreatment on the static contact angle of a bonding agent as a measure of dentin surface wettability. Materials &Methods: Twenty mid-coronal dentin surfaces were prepared and randomly allocated to four groups (n=5 according to the priming solutions. All segments were etched with 35% phosphoric acid gel for 15 s, rinsed for 30 s and dried. Each group was rehydrated with 10 µL of distilled water, 0.2 % chlorhexidine, 70% ethanol and 5.25% Sodium Hypochlorite respectively and the excess solution was removed after 60 sec using an absorbent paper. Using a micro syringe, a droplet of the Adper Single Bond 2 was placed on each prepared surface. Then the profile and the static contact angle of the droplet were analyzed with a video-based optical contact angle measuring system. The statistical analysis was performed using One-way ANOVA and Dunnett’s t tests (p<0.05. Results: There was a statistically significant difference between the water and sodium hypochlorite groups which indicates the negative effect sodium hypochlorite may have on dentinal surface energy. (p=0.013. The differences between the water and ethanol groups (p=0.168 and between the water and chlorhexidine groups (p=0.665 were not significant. Conclusion: The use of 5.25% sodium hypochlorite as a priming solution in bonding procedure is not recommended. There is no improvement in dentinal surface wettability by using 70% ethanol or 0.2% chlorhexidine instead of water and the recommendation for use of any of the two should be based on other long-term or short-term effects they may have on the bonding procedure.

  2. Buffering action of human dentin in vitro.

    Science.gov (United States)

    Camps, J; Pashley, D H

    2000-01-01

    The purpose of this study was to determine the relative contributions of the mineral and organic phases of dentin to its total buffering capacity and to compare the buffering abilities of normal and caries-affected dentin for acids used in adhesive dentistry. Disks of normal and caries-affected human coronal dentin 0.6 mm thick were prepared. Fifty microL of various acids were applied to the surface of mineralized or completely demineralized dentin for varying lengths of time. They were collected from the surface and combined with water rinses to permit titration of the total amount of acid applied, the amount recovered, the total amount that was taken up by the dentin, and the amount that diffused across dentin into 1 mL of water. Equal volumes of acids were applied to mineralized or demineralized dentin powder or hydroxyapatite powder. About 88% to 90% of applied acid was recovered from the surface; only 10% to 12% of the acid was taken up by dentin. Of the H+ that was taken up, only 1% to 2% actually diffused across 0.6 mm of dentin. Increasing the application time of 37% phosphoric acid did not increase the amount of H+ that diffused across dentin. Increasing the concentration of phosphoric acid from 10% to 65% produced only slight increases in H+ diffusion across dentin. There was no difference in the buffering capacity of normal vs caries-affected dentin disks. Almost all of the buffering capacity of dentin is due to its mineral phase. The high buffering capacity of dentin and the high reactivity of H+ insure that little H+ diffuses through dentin more than 0.6 mm thick.

  3. Influence of multi-wavelength laser irradiation of enamel and dentin surfaces at 0.355, 2.94, and 9.4 μm on surface morphology, permeability, and acid resistance.

    Science.gov (United States)

    Chang, Nai-Yuan N; Jew, Jamison M; Simon, Jacob C; Chen, Kenneth H; Lee, Robert C; Fried, William A; Cho, Jinny; Darling, Cynthia L; Fried, Daniel

    2017-12-01

    Ultraviolet (UV) and infrared (IR) lasers can be used to specifically target protein, water, and mineral, respectively, in dental hard tissues to produce varying changes in surface morphology, permeability, reflectivity, and acid resistance. The purpose of this study was to explore the influence of laser irradiation and topical fluoride application on the surface morphology, permeability, reflectivity, and acid resistance of enamel and dentin to shed light on the mechanism of interaction and develop more effective treatments. Twelve bovine enamel surfaces and twelve bovine dentin surfaces were irradiated with various combinations of lasers operating at 0.355 (Freq.-tripled Nd:YAG (UV) laser), 2.94 (Er:YAG laser), and 9.4 μm (CO 2 laser), and surfaces were exposed to an acidulated phosphate fluoride gel and an acid challenge. Changes in the surface morphology, acid resistance, and permeability were measured using digital microscopy, polarized light microscopy, near-IR reflectance, fluorescence, polarization sensitive-optical coherence tomography (PS-OCT), and surface dehydration rate measurements. Different laser treatments dramatically influenced the surface morphology and permeability of both enamel and dentin. CO 2 laser irradiation melted tooth surfaces. Er:YAG and UV lasers, while not melting tooth surfaces, showed markedly different surface roughness. Er:YAG irradiation led to significantly rougher enamel and dentin surfaces and led to higher permeability. There were significant differences in acid resistance among the various treatment groups. Surface dehydration measurements showed significant changes in permeability after laser treatments, application of fluoride and after exposure to demineralization. CO 2 laser irradiation was most effective in inhibiting demineralization on enamel while topical fluoride was most effective for dentin surfaces. Lasers Surg. Med. 49:913-927, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  4. Micromorphology of pelletized soil conditioners

    Science.gov (United States)

    Hirsch, Florian; Dietrich, Nils; Knoop, Christine; Raab, Thomas

    2017-04-01

    Soil conditioners produced by anaerobic digestion and subsequent composting of organic household waste, bear the potential to improve unproductive farmland together with a reduced input risk of unwanted pollutants into the soils. Within the VeNGA project (http://www.biogas-network.de/venga), soil conditioners from anaerobically digested organic household waste are tested for their potential to increase plant growth in glasshouse and field experiments. Because the production techniques of these soil conditioners may influence their physical and chemical behaviour in the soil, two different techniques for pelletizing the soil conditioners where applied. We present findings from a pot experiment with cereal that has been sampled after two months for micromorphological analyses. We visualize the decomposition and the physical behaviour of the soil conditioners. Pellets produced in an agglomeration mixer result in dense balls, that are only slightly decomposed after the trial. But the soil conditioners created under pressure in a screw extruder are rich in voids and have the potential of retaining more soil water.

  5. Adhesion of Porphyromonas gingivalis and Tannerella forsythia to dentin and titanium with sandblasted and acid etched surface coated with serum and serum proteins - An in vitro study.

    Science.gov (United States)

    Eick, Sigrun; Kindblom, Christian; Mizgalska, Danuta; Magdoń, Anna; Jurczyk, Karolina; Sculean, Anton; Stavropoulos, Andreas

    2017-03-01

    To evaluate the adhesion of selected bacterial strains incl. expression of important virulence factors at dentin and titanium SLA surfaces coated with layers of serum proteins. Dentin- and moderately rough SLA titanium-discs were coated overnight with human serum, or IgG, or human serum albumin (HSA). Thereafter, Porphyromonas gingivalis, Tannerella forsythia, or a six-species mixture were added for 4h and 24h. The number of adhered bacteria (colony forming units; CFU) was determined. Arg-gingipain activity of P. gingivalis and mRNA expressions of P. gingivalis and T. forsythia proteases and T. forsythia protease inhibitor were measured. Coating specimens never resulted in differences exceeding 1.1 log10 CFU, comparing to controls, irrespective the substrate. Counts of T. forsythia were statistically significantly higher at titanium than dentin, the difference was up to 3.7 log10 CFU after 24h (p=0.002). No statistically significant variation regarding adhesion of the mixed culture was detected between surfaces or among coatings. Arg-gingipain activity of P. gingivalis was associated with log10 CFU but not with the surface or the coating. Titanium negatively influenced mRNA expression of T. forsythia protease inhibitor at 24h (p=0.026 uncoated, p=0.009 with serum). The present findings indicate that: a) single bacterial species (T. forsythia) can adhere more readily to titanium SLA than to dentin, b) low expression of T. forsythia protease inhibitor may influence the virulence of the species on titanium SLA surfaces in comparison with teeth, and c) surface properties (e.g. material and/or protein layers) do not appear to significantly influence multi-species adhesion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Macromorphological and micromorphological studies of four selected passiflora species in peninsular malaysia

    International Nuclear Information System (INIS)

    Veeramohan, R.; Haron, N.W.

    2015-01-01

    Taxonomic studies of four selected Passiflora species; Passiflora edulis Sims (Passion fruit), Passiflora coccinea Aubl. (Scarlet passion flower), Passiflora foetida L. (Stinking passion flower) and Passiflora incarnata L. (Fragrant passion flower) were carried out to distinguish their morphological characteristics. Macromorphological characters on the leaves, flowers and fruits of all four Passiflora species were observed under a binocular microscope and they varied characteristically in terms of colour, texture and shape of flowers, leaves and fruits. Jeol JSM-7500F Scanning Electron Microscope was used to observe the micromorphological characters such as stomata, trichomes, and leaf surface indumentum of each Passiflora species. Micromorphologically, each species varied in types and sizes of stomata, epidermal. (author)

  7. Effect of surface treatments on the flexural properties and adhesion of glass fiber-reinforced composite post to self-adhesive luting agent and radicular dentin.

    Science.gov (United States)

    Elnaghy, Amr M; Elsaka, Shaymaa E

    2016-01-01

    This study evaluated the effect of different surface treatments on the flexural properties and adhesion of glass fiber post to self-adhesive luting agent and radicular dentin. Seventy-five single-rooted human teeth were prepared to receive a glass fiber post (Reblida). The posts were divided into five groups according to the surface treatment: Gr C (control; no treatment), Gr S (silanization for 60 s), Gr AP (airborne-particle abrasion), Gr HF (etching with 9 % hydrofluoric acid for 1 min), and Gr M10 (etching with CH2Cl2 for 10 min). Dual-cure self-adhesive luting agent (Rely X Unicem) was applied to each group for testing the adhesion using micropush-out test. Failure types were examined with stereomicroscope and surface morphology of the posts was characterized using a scanning electron microscopy (SEM). Flexural properties of posts were assessed using a three-point bending test. Data were analyzed using ANOVA and Tukey's HSD test. Statistical significance was set at the 0.05 probability level. Groups treated with M10 showed significantly higher bond strength than those obtained with other surface treatments (P C > S > AP > HF. Most failure modes were adhesive type of failures between dentin and luting agent (48.2%). SEM analysis revealed that the fiber post surfaces were modified after surface treatments. The surface treatments did not compromise the flexural properties of fiber posts. Application of M10 to the fiber post surfaces enhanced the adhesion to self-adhesive luting agent and radicular dentin.

  8. Effects of different surface treatments on bond strength of an indirect composite to bovine dentin

    Directory of Open Access Journals (Sweden)

    Laiza Tatiana Poskus

    2015-01-01

    Conclusions: Sandblasting was a safe surface treatment for the indirect composite, increasing the BS values. Hydrofluoric acid applied after sandblasting damaged the BS values and should not be recommended while ethanol and H2O2, when applied after sandblasting, were effective in increasing BS values.

  9. Femtosecond laser ablation of dentin

    International Nuclear Information System (INIS)

    Alves, S; Vilar, R; Oliveira, V

    2012-01-01

    The surface morphology, structure and composition of human dentin treated with a femtosecond infrared laser (pulse duration 500 fs, wavelength 1030 nm, fluences ranging from 1 to 3 J cm -2 ) was studied by scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The average dentin ablation threshold under these conditions was 0.6 ± 0.2 J cm -2 and the ablation rate achieved in the range 1 to 2 µm/pulse for an average fluence of 3 J cm -2 . The ablation surfaces present an irregular and rugged appearance, with no significant traces of melting, deformation, cracking or carbonization. The smear layer was entirely removed by the laser treatment. For fluences only slightly higher than the ablation threshold the morphology of the laser-treated surfaces was very similar to the dentin fracture surfaces and the dentinal tubules remained open. For higher fluences, the surface was more porous and the dentin structure was partially concealed by ablation debris and a few resolidified droplets. Independently on the laser processing parameters and laser processing method used no sub-superficial cracking was observed. The dentin constitution and chemical composition was not significantly modified by the laser treatment in the processing parameter range used. In particular, the organic matter is not preferentially removed from the surface and no traces of high temperature phosphates, such as the β-tricalcium phosphate, were observed. The achieved results are compatible with an electrostatic ablation mechanism. In conclusion, the high beam quality and short pulse duration of the ultrafast laser used should allow the accurate preparation of cavities, with negligible damage of the underlying material. (paper)

  10. A review: Biodegradation of resin–dentin bonds

    Directory of Open Access Journals (Sweden)

    Masanori Hashimoto

    2011-02-01

    Full Text Available Resin–dentin bonding was first achieved through mechanical hybridization between resin and collagen fibrils using a functional monomer containing resin system. In the last decade, new adhesive resin systems were frequently released onto the market within a short-period of time. Before and after commercialization, the bond integrity has been tested by bond tests, and leakage evaluation by researchers, but it is very difficult for clinicians to obtain a comprehensive, up-to-date understanding of their nature and degradation. Although newly developed adhesive resins have attempted to improve the bond strength at least in the first 24 h after bonding, the long-term durability of the bonds has not yet been established analytically. However, numerous recent studies have shown micromorphological evidence of biodegradation of resin–dentin bonds, due to hydrolysis of the resin and collagen fibrils within the bonds. This review mainly summarizes the most recent work in biodegradation of resin–dentin bonds based on micromorphological analyses of data obtained by scanning and transmission electron microscopy.

  11. Comparative labellar micromorphology of Zygopetalinae (Orchidaceae).

    Science.gov (United States)

    Davies, Kevin L; Stpiczynska, Malgorzata

    2011-10-01

    Molecular evidence indicates that the Neotropical sub-tribe Zygopetalinae is sister to Maxillariinae. Most members of the latter sub-tribe have deceit pollination strategies, but some species produce rewards such as nectar, pseudopollen, resin and wax, and are pollinated by a range of pollinators that include stingless bees (Meliponini), wasps and hummingbirds. By contrast, relatively little is known about the pollination of Zygopetalinae species. However, some are pollinated by fragrance-gathering, male euglossine bees or employ nectar deceit strategies. The aim of this study is to describe the labellar micromorphology of Zygopetalinae and to compare it with that of Maxillariinae sensu lato (s.l.) as part of an ongoing project to record the range of labellar characters found within the tribe Maxillarieae, and to assess whether these characters represent synapomorphies or homoplasies resulting from similar pollination pressures. The labella of 31 species of Zygopetalinae, including Cryptarrhena R. Br. and representatives of the Zygopetalum, Huntleya and Warrea clades, were examined using light microscopy and scanning electron microscopy, and the range of labellar characters was recorded. These characters were subsequently compared with those of Maxillariinae s.l. which formed the subject of our previous investigations. The labellar micromorphology of Zygopetalinae is less diverse than that of Maxillariinae and does not reflect the currently accepted phylogeny of the former sub-tribe based on molecular studies. Instead, the relative uniformity in labellar micromorphology of Zygopetalinae is probably due to homoplasies resulting from similar pollinator pressures. Labellar trichomes are relatively uncommon in Zygopetalinae, but occur in certain members of both the Zygopetalum and Huntleya clades. Trichomes are unbranched, uniseriate and multicellular with rounded apices, or unbranched and unicellular, with tapering, pointed and flexuose apices. Hitherto, unicellular

  12. Micromorphology and histochemical traits of staminal osmophores in Asphodelus aestivus Brot. flower

    OpenAIRE

    Elżbieta Weryszko-Chmielewska; Mirosława Chwil; Thomas Sawidis

    2012-01-01

    The conducted studies pertained to micromorphology of the surface of epidermis cells and histological traits of staminal filaments of Asphodelus aestivus Brot. flowers. The structure of the filaments was analyzed in a light microscope (LM) using various histochemical techniques. The morphology of the surface of the epidermis of filaments was observed in scanning electron microscope (SEM). Filaments Asphodelus aestivus accrete together with the basal part of the abaxial surface with the leaves...

  13. Microshear bonding effectiveness of different dentin regions

    Directory of Open Access Journals (Sweden)

    Anelise F Montagner

    2015-01-01

    Full Text Available Aim: The aim of this in vitro study was to evaluate the influence of dentin surfaces with different tubule orientation on bond strength of a multimode adhesive system. Materials and Methods: Twenty human molars were selected and prepared in different ways in order to produce different dentin regions. The teeth were randomized (n = 5 according to the application modes of a multimode adhesive system (etch-and-rinse and self-etching and to the dentin region (occlusal and proximal - 1.5 mm depth from dentinoenamel junction. Cylindrical restorations were performed on dentin with a starch tube. The samples remained immersed in distilled water for 24 h and the microshear bond strength (μSBS test was performed. The μSBS values were expressed in MPa and analyzed with ANOVA and Tukey′s test (P < 0.05. Results: There was no significant difference in the bond strength values between the application modes of the adhesive system (P = 0.19; however, the dentin regions (P < 0.05 significantly affected the μSBS. The proximal dentin presented higher bond strength values than occlusal dentin. Conclusion: The dentin surfaces with different tubule orientation influenced the bonding effectiveness of the adhesive system tested.

  14. MICROMORPHOLOGICAL AND CHEMICAL ASPECTS OF SOME LICHENIZED FUNGI SPECIES

    Directory of Open Access Journals (Sweden)

    PÎNDARU DIANA-MIHAELA

    2012-12-01

    Full Text Available At present, lichenized fungi are used in biomonitoring studies of air quality, being good receptors in the climate change. This paper aims to investigate surface micromorphology of Xanthoria parietina and Phaeophyscia orbicularis species (Lecanoromycetes, Ascomycota. The study also includes the investigation of selected chemical parameters as pH and conductivity of the lichenized fungi samples collected from various locations in the Iaşi County (Romania. Measurements of the pH provide information on the degree of pollution in the location of interest. Bark trees pH was also investigated in order to see if our matrix substrate influences the pH of the interest lichenized fungi samples.

  15. Peritubular dentin lacks piezoelectricity.

    Science.gov (United States)

    Habelitz, S; Rodriguez, B J; Marshall, S J; Marshall, G W; Kalinin, S V; Gruverman, A

    2007-09-01

    Dentin is a mesenchymal tissue, and, as such, is based on a collagenous matrix that is reinforced by apatite mineral. Collagen fibrils show piezoelectricity, a phenomenon that is used by piezoresponse force microscopy (PFM) to obtain high-resolution images. We applied PFM to image human dentin with 10-nm resolution, and to test the hypothesis that zones of piezoactivity, indicating the presence of collagen fibrils, can be distinguished in dentin. Piezoelectricity was observed by PFM in the dentin intertubular matrix, while the peritubular dentin remained without response. High-resolution imaging of chemically treated intertubular dentin attributed the piezoelectric effect to individual collagen fibrils that differed in the signal strength, depending on the fibril orientation. This study supports the hypothesis that peritubular dentin is a non-collagenous tissue and is thus an exception among mineralized tissues that derive from the mesenchyme.

  16. Micromorphology of cactus-pear (Opuntia ficus-indica (L.) Mill) cladodes based on scanning microscopies.

    Science.gov (United States)

    Ben Salem-Fnayou, Asma; Zemni, Hassène; Nefzaoui, Ali; Ghorbel, Abdelwahed

    2014-01-01

    Cladode ultrastructural features of two prickly and two spineless Opuntia ficus-indica cultivars were examined using environmental scanning electron and atomic force microscopies. Observations focused on cladode as well as spine and glochid surface micromorphologies. Prickly cultivars were characterized by abundant cracked epicuticular wax deposits covering the cladode surface, with an amorphous structure as observed by AFM, while less abundant waxy plates were observed by ESEM on spineless cultivar cladodes. Further AFM observations allowed a rough granular and crystalloid epicuticular wax structure to be distinguished in spineless cultivars. Regarding spine micromorphology, prickly cultivars had strong persistent spines, observed by ESEM as a compact arrangement of oblong epidermal cells with a rough granular structure. However, deciduous spines in spineless cultivars had a broken transversely fissured epidermis covering a parallel arrangement of fibres. Through AFM, the deciduous spine surface presented an irregular hilly and smooth microrelief while persistent spines exhibited rough helical filamentous prints. ESEM and AFM studies of cladode surfaces from prickly and spineless cactus pear cultivars revealed valuable micro-morphological details that ought to be extended to a large number of O. ficus-indica cultivars. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Use of poly (amidoamine dendrimer for dentinal tubule occlusion: a preliminary study.

    Directory of Open Access Journals (Sweden)

    Tianda Wang

    Full Text Available The occlusion of dentinal tubules is an effective method to alleviate the symptoms caused by dentin hypersensitivity, a significant health problem in dentistry and daily life. The in situ mineralization within dentinal tubules is a promising treatment for dentin hypersensitivity as it induces the formation of mineral on the sensitive regions and occludes the dentinal tubules. This study was carried out to evaluate the in vitro effect of a whole generation poly(amidoamine (PAMAM dendrimer (G3.0 on dentinal tubule occlusion by inducing mineralization within dentinal tubules. Dentin discs were treated with PAMAM dendrimers using two methods, followed by the in vitro characterization using Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR, X-ray diffraction (XRD, Field emission scanning electron microscopy (FE-SEM and Energy-Dispersive X-ray Spectroscopy (EDS. These results showed that G3.0 PAMAM dendrimers coated on dentin surface and infiltrated in dentinal tubules could induce hydroxyapatite formation and resulted in effective dentinal tubule occlusion. Moreover, crosslinked PAMAM dendrimers could induce the remineralization of demineralized dentin and thus had the potential in dentinal tubule occlusion. In this in vitro study, dentinal tubules occlusion could be achieved by using PAMAM dendrimers. This could lead to the development of a new therapeutic technique for the treatment of dentin hypersensitivity.

  18. Influence of Immediate Dentin Sealing on the Shear Bond Strength of Pressed Ceramic Luted to Dentin with Self-Etch Resin Cement

    Directory of Open Access Journals (Sweden)

    Robert Dalby

    2012-01-01

    Full Text Available Objectives. To examine the effect of immediate dentin sealing (IDS, with dentin bonding agents (DBAs applied to freshly cut dentin, on the shear bond strength of etched pressed ceramic luted to dentin with RelyX Unicem (RXU cement. Method. Eighty extracted noncarious third molars were ground flat to expose the occlusal dentin surfaces. The teeth were randomly allocated to five groups (A to E of sixteen teeth each. Groups A to D were allocated a dentin bonding agent (Optibond FL, One Coat Bond, Single Bond, or Go! that was applied to the dentin surface to mimic the clinical procedure of IDS. These specimen groups then had etched glass ceramic discs (Authentic luted to the sealed dentin surface using RXU. Group E (control had etched glass ceramic discs luted to the dentin surface (without a dentin bonding agent using RXU following the manufacturer’s instructions. All specimens were stored for one week in distilled water at room temperature and then shear stressed at a constant cross-head speed of 1 mm per minute until failure. Statistical analysis was performed by ANOVA followed by post hoc Tukey HSD method (0.05 in the SBS between the test groups (A–D or the control (group E. Conclusion. IDS using the dentin bonding agents tested does not statistically (>0.05 affect the shear bond strength of etched pressed ceramic luted to dentin with RXU when compared to the control.

  19. The effect of propolis fluoride on caries dentine activity

    Science.gov (United States)

    Darwita, Risqa Rina; Soekanto, Sri Angky; Finisha, Andanali Rhukul; Wahyuni, Hardiati Nur; Andiani, Salsabila Ghina

    2018-02-01

    This research was conducted to analyze the effect of propolis fluoride on the occurrence of arrested caries dentine surface. The design of the study was a clinical trial experimental. The respondent were primary school students aged 6-8 years, from primary school in Kukusan, Depok, West Java, Indonesia. They were screened of dental examination and the total number of 296 children with an age range of 6-8 year old were included in the study. All students who had dentin caries were get dental treatment with propolis fluoride topical application in dentin caries surface. After one month, two months and four months all students who were got propolis fluoride topical application in dentin caries surface were controlled. All data were analyzed by Wilcoxon test. The total number of dentinal decay of 296 student was 1740 surfaces indicated to Flolis topical application. After one, two and three months of Flolis application, all arrested of dentinal decay was evaluated, the result of evaluation from the second month to the third month evaluation was found that the arrested dentinal caries surfaces were decreased significantly at 29.36% (pcaries surface from the first month to the third month was decreased significantly at 38.62% (pcaries, and their ability to arrest dental caries was significantly different. Flolis was found to be effective in arresting dentinal caries surface until three months application, and should be repeated after 3 months of Flolis application.

  20. Morphological and micromorphological characteristics of Desmodium fruits (Leguminosae: Papilionoideae

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    Daiane M. Freitas

    2014-12-01

    Full Text Available The genus Desmodium is represented in Santa Catarina State, Brazil, by 13 species, all with lomentaceous fruits. Shape, size and isthmus margin of loments vary, while the surface is glabrous, or covered by trichomes of different types. Morphological diversity of trichomes becomes particularly relevant to taxonomic description. The trichome types present on the surface of Desmodium fruits provide data for the identification and classification of species in the State. To assess this, three fruits of each species were collected and deposited at two herbaria, HBR and FLOR, in Santa Catarina, Brazil. Some rehydrated samples were examined using light microscopy (LM; and some sections were exposed to the following histochemical reagents: Sudan III for oils and Thionine for mucilage. The structural aspects of trichomes can be classified into uni- or multicel- lular and may still be simple, i.e., nonglandular or glandular. Using scanning electron microscopy (SEM, five types of trichomes were identified and analyzed among the Desmodium species studied: uncinate, uniseriate, globose multicellular, globose unicellular and subulate. Characteristics, such as loment margin and article form, glabrescent or pillous indument, trichome type, with or without papillous epidermal cells and epicuticular striations, showed relevant diagnostic value. An identification key was developed for Desmodium species from Santa Catarina State, Brazil, based on macro and micromorphological characters of the fruit.

  1. Dentine microhardness after different methods for detection and removal of carious dentine tissue

    Directory of Open Access Journals (Sweden)

    Fernanda Brandão Mollica

    2012-08-01

    Full Text Available There are several methods for identifying carious dentinal tissue aiming to avoid removal of healthy dentinal tissue. OBJECTIVES: The purpose of this study was to test different methods for the detection of carious dentinal tissue regarding the amount of carious tissue removed and the remaining dentin microhardness after caries removal. MATERIAL AND METHODS: The dentin surfaces of 20 bovine teeth were exposed and half of the surface was protected with nail polish. Cariogenic challenge was performed by immersion in a demineralizing solution for 14 days. After transverse cross-section of the crown, the specimens were divided into four groups (n=10, according to the method used to identify and remove the carious tissue: "Papacárie", Caries-detector dye, DIAGNOdent and Tactile method. After caries removal, the cross-sectional surface was included in acrylic resin and polished. In a microhardness tester, the removed dentin thickness and the Vickers microhardness of the following regions were evaluated: remaining dentin after caries removal and superficial and deep healthy dentin. RESULTS: ANOVA and Tukey's test (α=0.05 were performed, except for DIAGNOdent, which did not detect the presence of caries. Results for removed dentin thickness were: "Papacárie" (424.7±105.0; a, Caries-detector dye (370.5±78.3; ab, Tactile method (322.8±51.5; bc. Results for the remaining dentin microhardness were: "Papacárie" (42.2±10.5; bc, Caries-detector dye (44.6±11.8; abc, Tactile method (24.3±9.0; d. CONCLUSIONS: DIAGNOdent did not detect the presence of carious tissue; Tactile method and "Papacárie" resulted in the least and the most dentinal thickness removal, respectively; Tactile method differed significantly from "Papacárie" and Caries-detector dye in terms of the remaining dentin microhardness, and Tactile method was the one which presented the lowest microhardness values.

  2. Micromorphology of glandular structures in Echium vulgare L. flowers

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    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The micromorphology of selected elements of Echium vulgare L. flowers was investigated, with special attention to the structure of the nectaries and the stigma of the pistil as well as types of trichomes occurring on the surface of the calyx. The nectary had the shape of an uneven disc located around the lower region of the four-parted ovary of the pistil. The glandular cells formed a tier with a height of 330 μm and a radial width of 144 μm. Nectar was secreted onto the nectary surface through anomocytic stomata located at the level of other epidermal cells. Most of the stomata were open, with a different dimension of the pore. Their largest number was observed at the base of the nectary, and 462 stomata were noted on the whole surface of the nectary. The cuticle on the surface of the guard cells formed fine, circular striae. The subsidiary cells formed striated cuticular ornamentation, with the striae arranged radially in the direction of the stoma, whereas on the surface of other epidermal cells the striae formed an arrangement with different directions. The epidermis on the surface of the stigma formed regularly arranged papillae with a fan-shaped, expanded upper part which had corrugated outer walls, whereas the base of the cell formed a widened small column. The epidermis of the abaxial part of the calyx was covered by numerous non-glandular trichomes of different length which were made up of one or several cells. The glandular trichomes in the epidermis of the calyx grew with smaller density compared to the protective trichomes, and they were composed of a 1-2-celled stalk and a glandular head.

  3. Riverbed Micromorphology of the Yangtze River Estuary, China

    Directory of Open Access Journals (Sweden)

    Shuaihu Wu

    2016-05-01

    Full Text Available Dunes are present in nearly all fluvial channels and are vital in understanding sediment transport, deposition, and flow conditions during floods of rivers and estuaries. This information is pertinent for helping developing management practices to reduce risks in river transportation and engineering. Although a few recent studies have investigated the micromorphology of a portion of the Yangtze River estuary in China, our understanding of dune development in this large estuary is incomplete. It is also poorly understood how the development and characteristics of these dunes have been associated with human activities in the upper reach of the Yangtze River and two large-scale engineering projects in the estuarine zone. This study analyzed the feature in micromorphology of the entire Yangtze River estuary bed over the past three years and assessed the morphological response of the dunes to recent human activities. In 2012, 2014, and 2015, multi-beam bathymetric measurements were conducted on the channel surface of the Yangtze River estuary. The images were analyzed to characterize the subaqueous dunes and detect their changes over time. Bottom sediment samples were collected for grain size analysis to assess the physical properties of the dunes. We found that dunes in the Yangtze River estuary can be classified in four major classes: very large dunes, large dunes, medium dunes, and small dunes. Large dunes were predominant, amounting to 51.5%. There was a large area of dunes developed in the middle and upper reaches of the Yangtze River estuary and in the Hengsha Passage. A small area of dunes was observed for the first time in the turbidity maximum zone of the Yangtze River estuary. These dunes varied from 0.12 to 3.12 m in height with a wide range of wavelength from 2.83 to 127.89 m, yielding a range in height to wavelength of 0.003–0.136. Sharp leeside slope angles suggest that the steep slopes of asymmetrical dunes in the middle and upper

  4. Effect of Nanofiller Addition to an Experimental Dentin Adhesive on Microtensile Bond Strength to Human Dentin

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    SH. Kasraei

    2009-06-01

    Full Text Available Objective: The purpose of the study was to evaluate the influence of adding nanofiller particles to a dentin bonding agent on resin-dentin bond strength.Materials and Methods: Fifty-four human intact premolar teeth were divided in to 6 groups of nine. The teeth were ground on occlusal surfaces and polished with 320 and then 600 grit silicon carbide papers. An experimental bonding system based on acetone/alcoholsolvent was provided with filler contents of 0.0, 0.5, 1.0, 2.5, 5.0, and 10.0 weight percent fumed silica nanofiller. After dentin surface etching, rinsing and blot drying, the experimentalbonding agents were applied to dentin surface. A composite resin was, then,bonded to the dentin on the bonding agent. The specimens were thermocycled for 500 cycles and sectioned in stick form. After two week of storage in distilled water, resin-dentin microtensile bond strength of the specimens was measured. Data were analyzed by one way ANOVA and DunnettT3 tests.Results: Bond strength to dentin was significantly affected by the filler level. Minimum and maximum resin-microtensile bond strength was in the experimental bonding agent with no filler (5.88 MPa and with filler level of 1.0 weight percent (15.15 MPa, respectively,and decreased with the increase of filler content down to 8.95 MPa for the filler level of 10.0 weight percent.Conclusion: Filler content seems to be one of the important factors influencing the bond strength of dental adhesives. Maximum dentin bond strength was obtained with 1% silanized nanofiller silica added to experimental adhesive system.

  5. Shear bond strength of two bonding systems on dentin surfaces prepared with Er:YAG laser; Resistencia de uniao ao cisalhamento de dois sistemas adesivos em superficies dentinarias preparadas com laser de Er:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Magro, Eduardo

    2001-07-01

    The purpose of this study was to examine the shear bond strength of two bonding dentin systems, one 'one step' (Single Bond - 3M) and one 'self-etching' (Prompt-L-ESPE), when applied on dentin surfaces prepared with Er:YAG laser (2,94{mu}m) that underwent ar not, acid etched. Forty one human molars just extracted were selected and after the cut with diamond disc and included in acrylic resin, resulting in 81 specimens (hemi crowns). After, the specimens were divided in one group treated with sand paper and another two groups treated with Er:YAG laser with 200 mJ and 250 mJ of energy and 2 Hz of frequency. Next, the prepared surfaces received three treatments with following application: 1) acid + Single Bond + Z 250 resin, 2) prompt-L-Pop + Z 250 resin, and 3) acid without, Single Bond + Z 250 resin. The Z 250 resin was applied and photopolymerized in increments on a Teflon matrix that belonged to an apparatus called 'Assembly Apparatus' machine producing cylinders of 3,5 mm of diameter and 5 mm of height. After these specimens were submitted to thermo cycling during 1 minute the 55 deg C and during 1 minute with 5 deg C with a total of 500 cycles for specimen, and the measures of shear bond strength were abstained using EMIC model DL 2000 rehearsed machine, with speed of 0,5 mm/min, measuring the final rupture tension (Mpa). The results showed an statistic superiority of 5% of probability level in dentin flattened with sandpaper and with laser using 200 mJ of energy with aspect to the ones flattened with laser using 250 mJ of energy. It was observed that using 'Single Bond' bonding dentin system the marks were statistically superior at 5% of probability with reference to the use of the Prompt-L-Pop adhesive system. So, it was concluded that Er:YAG Laser with 200 mJ of energy produced similar dentin cavity prepare than sandpaper and Single Bond seemed the best bonding agent system between restorative material and dentin

  6. Superficial roughness on composite surface, composite enamel and composite dentin junctions after different finishing and polishing procedures. Part I: roughness after treatments with tungsten carbide vs diamond burs.

    Science.gov (United States)

    Ferraris, Federico; Conti, Alessandro

    2014-01-01

    The aim of this study is to investigate different instruments for finishing composite restorations, as well as examining different surfaces and interfaces of the same restoration. The null hypothesis is represented by the fact that there are no significant differences on roughness of composite restorations finishing between tungsten carbide and diamond burs, furthermore the null hypothesis is that there are no significant differences on roughness between finishing on composite surfaces (C), compositeenamel (CE) and composite-dentin (CD) interfaces. The study was performed on 28 teeth, and class V cavities were prepared on the extracted teeth. Restorations were done in Filtek XTE nanofilled composite (3M Espe) in a standardized method, to then be finished. A comparison was made in the phase 1 between tungsten carbide burs (16 blades), diamond burs (46 μm), with a similar shape by the same manufacturer (Komet). Each surface received 5 bur applications. Consequently, an analysis with a profilometer was performed. Phase 2 involved further confrontation of ulterior finishing with ultrafine tungsten carbide burs (30 blades) and with extra and ultrafine diamond burs (25 and 8 μm) (the same shape as previously mentioned). A second analysis was then performed with a profilometer. All measurements were taken on C surfaces, CE and CD interfaces. Statistical analyses were carried out with c2 test (a = 0.05). The finishing procedures with fine grit or toothing burs gave a better smoothness with tungsten carbide burs compared to diamond burs. While with the ultrafine grit no significant differences were noted between tungsten carbide and diamond burs on the CE and CD interfaces, the diamond bur left less superficial roughness on the C surfaces. With regards to the superficial roughness of the different areas of restoration, it can be concluded that: minor roughness was detected on C surfaces, while the CD interface had the most superficial roughness, regardless of whether the

  7. Carabelli's trait revisited: an examination of mesiolingual features at the enamel-dentine junction and enamel surface of Pan and Homo sapiens upper molars.

    Science.gov (United States)

    Ortiz, Alejandra; Skinner, Matthew M; Bailey, Shara E; Hublin, Jean-Jacques

    2012-10-01

    Carabelli's trait is a morphological feature that frequently occurs on the mesiolingual aspect of Homo sapiens upper molars. Similar structures also referred to as Carabelli's trait have been reported in apes and fossil hominins. However, the morphological development and homology of these mesiolingual structures among hominoids are poorly understood. In this study, we employ micro-computed tomography to image the enamel-dentine junction (EDJ) and outer enamel surface (OES) of Pan (n = 48) and H. sapiens (n = 52) upper molars. We investigate the developmental origin of mesiolingual features in these taxa and establish the relative contribution of the EDJ and enamel cap to feature expression. Results demonstrate that mesiolingual features of H. sapiens molars develop at the EDJ and are similarly expressed at the OES. Morphological variation at both surfaces in this taxon can satisfactorily be assessed using standards for Carabelli's trait developed by the Arizona State University Dental Anthropology System (ASUDAS). Relative to H. sapiens, Pan has an even greater degree of correspondence in feature expression between the EDJ and OES. Morphological manifestations in Pan molars are not necessarily limited to the protocone and are best characterized by a lingual cingulum that cannot be captured by the ASUDAS. Cusp-like structures, similar to those seen in marked Carabelli's trait expressions in H. sapiens, were not found in Pan. This study provides a foundation for further analyses on the evolutionary history of mesiolingual dental traits within the hominoid lineage. It also highlights the wealth of morphological data that can be obtained at the EDJ for understanding tooth development and for characterizing tooth crown variation in worn fossil teeth. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Remineralizing Efficacy of Fluorohydroxyapatite Gel on Artificial Dentinal Caries Lesion

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    Qianqian Wang

    2015-01-01

    Full Text Available The aim was to evaluate the remineralizing efficacy of fluorohydroxyapatite (FHA gel on artificial dentinal caries lesion in vitro. Artificial carious lesions were made on occlusal cavities of teeth by exposing the dentin surface to a demineralizing solution. Each cavity was capped with a 3 mm thick FHA gel for 4 weeks. After the FHA gel was removed, the surface morphology and structure of the dentin were characterized by scanning electron microscopy (SEM, energy-dispersive X-ray spectroscopy (EDX, X-ray diffraction (XRD, and Fourier transform infrared spectroscopy (FT-IR. The dentin mineral density (DMD was measured by micro-computed tomography (Micro-CT. A layer of dense and orderly hexagonal crystal structure, with average diameter of 1 μm and thickness of 4~5 μm, could be observed on dentin surface. These crystals exhibited elemental peaks for calcium, phosphorus, carbon, and oxygen and characteristic peaks of hydroxyapatite (HA and fluorapatite (FA via XRD and FT-IR. The DMD of dentin surface layer significantly increased after it was capped with FHA gel (P<0.05. In the present study, the FHA gel could rapidly construct apatite on the artificial dentin caries surface and significantly increase the mineral density, which suggests that FHA gel might be a proper IPT material with remineralizing function.

  9. Dentin and pulp sense cold stimulus.

    Science.gov (United States)

    Tokuda, Masayuki; Tatsuyama, Shoko; Fujisawa, Mari; Morimoto-Yamashita, Yoko; Kawakami, Yoshiko; Shibukawa, Yoshiyuki; Torii, Mistuso

    2015-05-01

    Dentin hypersensitivity is a common symptom, and recent convergent evidences have reported transient receptor potential (TRP) channels in odontoblasts act as mechanical and thermal molecular sensor, which detect stimulation applied on the exposed dentin surface, to drive multiple odontoblastic cellular functions, such as sensory transduction and/or dentin formation. In the present study, we confirmed expression of TRP melastatin subfamily member-8 (TRPM8) channels in primary cultured cells derived from human dental pulp cells (HPCs) and mouse odontoblast-lineage cells (OLCs) as well as in dentin matrix protein-1 (DMP-1) and dentin sialoprotein (DSP) positive acutely isolated rat odontoblasts from dental pulp tissue slice culture by immunohistochemical analyses. In addition, we detected TRPM8 channel expression on HPCs and OLCs by RT-PCR and Western blotting analyses. These results indicated that both odontoblasts and dental pulp cells express TRPM8 channels in rat, mouse and human, and therefore we hypothesize they may contribute as cold sensor in tooth. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Effects of endodontic tri-antibiotic paste on bond strengths of dentin adhesives to coronal dentin

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    Parvin Mirzakoucheki

    2015-05-01

    Full Text Available Objectives The aim of this study was to evaluate the effects of tri-antibiotic paste (TAP on microtensile bond strengths (MTBS of dental adhesives to dentin. Materials and Methods Sixty extracted molars had their occlusal surfaces flattened to expose dentin. They were divided into two groups, i.e., control group with no dentin treatment and experimental group with dentin treatment with TAP. After 10 days, specimens were bonded using self-etch (Filtek P90 adhesive or etch-and-rinse (Adper Single Bond Plus adhesives and restored with composite resin. Teeth were sectioned into beams, and the specimens were subjected to MTBS test. Data were analyzed using two-way ANOVA and post hoc Tukey tests. Results There was a statistically significant interaction between dentin treatment and adhesive on MTBS to coronal dentin (p = 0.003. Despite a trend towards worse MTBS being noticed in the experimental groups, TAP application showed no significant effect on MTBS (p = 0.064. Conclusions The etch-and-rinse adhesive Adper Single Bond Plus presented higher mean bond strengths than the self-etch adhesive Filtek P90, irrespective of the group. The superior bond performance for Adper Single Bond when compared to Filtek P90 adhesive was confirmed by a fewer number of adhesive failures. The influence of TAP in bond strength is insignificant.

  11. Effects of in-office bleaching on human enamel and dentin. Morphological and mineral changes.

    Science.gov (United States)

    Llena, Carmen; Esteve, Irene; Forner, Leopoldo

    2018-05-01

    The effects of HP-based products upon dental enamel and dentin are inconclusive. To evaluate changes in micromorphology and composition of calcium (Ca) and phosphate (P) in enamel and dentin after the application of 37.5% hydrogen peroxide (HP) and 35% carbamide peroxide (CP) METHODS: Crowns of 20 human teeth were divided in two halves. One half was used as control specimen and the other as experimental specimen. The control specimens were kept in artificial saliva, and the experimental specimens were divided into four groups (n=5 each): group 1 (enamel HP for 45min); group 2 (dentin HP for 45min); group 3 (enamel CP for 90min); and group 4 (dentin CP for 90min). The morphological changes were evaluated using confocal laser scanning microscopy (CLSM), while the changes in the composition of Ca and P were assessed using environmental scanning electron microscopy combined with a microanalysis system (ESEM+EDX). The results within each group and between groups were compared using the Wilcoxon test and Mann-Whitney U-test, respectively (p0.05). When bleaching products with a neutral pH are used in clinical practice, both, the concentration and the application time should be taken into account in order to avoid possible structural and mineral changes in enamel and dentin. Copyright © 2018 Elsevier GmbH. All rights reserved.

  12. Prevention of root caries with dentin adhesives.

    Science.gov (United States)

    Grogono, A L; Mayo, J A

    1994-04-01

    This in vitro investigation determined the feasibility of using dentin adhesives to protect root surfaces against caries. The roots of 22 recently extracted human teeth were all painted with a protective lacquer leaving two unprotected small windows. On each specimen, one window (control) was left untreated and the other window (experimental) was treated using a dentin adhesive (Scotchbond Multi-Purpose). The roots were then immersed in an in vitro acetate/calcium/phosphate demineralization model at pH 4.3. After 70 days, the samples were removed and sectioned through the windows. The undecalcified ground sections were examined under transmitted and polarized light. Lesions characteristic of natural root caries were seen in the untreated control windows. No such lesions were apparent in the experimental windows. The results of this preliminary study suggest that dentin adhesives may provide protection against root caries.

  13. Foliar micromorphology of Lippia javanica (Burm.F) Spreng ...

    African Journals Online (AJOL)

    Background: Lippia javanica (Burm.F.) Spreng is an aromatic indigenous South African plant with culinary and medicinal values. This study investigated the foliar morphology and elemental composition of the plant because not much data concerning the anatomical and micro-morphological features can be found in ...

  14. In vivo remineralization of dentin using an agarose hydrogel biomimetic mineralization system

    Science.gov (United States)

    Han, Min; Li, Quan-Li; Cao, Ying; Fang, Hui; Xia, Rong; Zhang, Zhi-Hong

    2017-02-01

    A novel agarose hydrogel biomimetic mineralization system loaded with calcium and phosphate was used to remineralize dentin and induce the oriented densely parallel packed HA layer on defective dentin surface in vivo in a rabbit model. Firstly, the enamel of the labial surface of rabbits’ incisor was removed and the dentin was exposed to oral environment. Secondly, the hydrogel biomimetic mineralization system was applied to the exposed dentin surface by using a custom tray. Finally, the teeth were extracted and evaluated by scanning electron microscopy, X-ray diffraction, and nanoindentation test after a certain time of mineralization intervals. The regenerated tissue on the dentin surface was composed of highly organised HA crystals. Densely packed along the c axis, these newly precipitated HA crystals were perpendicular to the underlying dental surface with a tight bond. The demineralized dentin was remineralized and dentinal tubules were occluded by the grown HA crystals. The nanohardness and elastic modulus of the regenerated tissue were similar to natural dentin. The results indicated a potential clinical use for repairing dentin-exposed related diseases, such as erosion, wear, and dentin hypersensitivity.

  15. Effects of hydrogen peroxide bleaching strips on tooth surface color, surface microhardness, surface and subsurface ultrastructure, and microchemical (Raman spectroscopic) composition.

    Science.gov (United States)

    Duschner, Heinz; Götz, Hermann; White, Donald J; Kozak, Kathleen M; Zoladz, James R

    2006-01-01

    This study examined the effects of hydrogen peroxide tooth bleaching strips on the surface hardness and morphology of enamel and the ultrastructure and chemical composition of enamel and dentin in vitro. Sound human molars were ground and polished to prepare a uniform substrate for bleaching treatments. A cycling treatment methodology was employed which alternated ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching treatments included commercial Crest Whitestrips bleaching strips, which utilize hydrogen peroxide in a gel as the in situ bleaching source at 6.0 and 6.5% concentrations of H2O2. Control treatments included an untreated group. Crest Whitestrips bleaching included treatment exposures simulating 2x the recommended clinical exposures (28 hours bleaching). Surface color measurements were taken prior to and following bleaching to ensure tooth bleaching activity. The effects of bleach on physical properties of enamel were assessed with microhardness measures. Ultrastructural effects were classified by surface and subsurface confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) techniques. In addition, the effects of bleaching on tooth microchemical composition was studied in different tooth regions by coincident assessment of Raman spectroscopic signature. Color assessments confirmed significant ex vivo tooth bleaching by Whitestrips. Surface microhardness and SEM measures revealed no deleterious effects on the enamel surfaces. CLSM micromorphological assessments supported the safety of hydrogen peroxide bleaching strips both on surface and subsurface enamel, DEJ, and dentin ultrastructure. Raman spectroscopy analysis demonstrated no obvious effects of bleaching treatments on the microchemical composition of enamel and dentin. These results confirm that tooth bleaching with hydrogen peroxide whitening strips does not produce changes in surface

  16. Optothermal transfer simulation in laser-irradiated human dentin.

    Science.gov (United States)

    Moriyama, Eduardo H; Zangaro, Renato A; Lobo, Paulo D C; Villaverde, Antonio Balbin; Pacheco, Marcos T; Watanabe, Ii-Sei; Vitkin, Alex

    2003-04-01

    Laser technology has been studied as a potential replacement to the conventional dental drill. However, to prevent pulpal cell damage, information related to the safety parameters using high-power lasers in oral mineralized tissues is needed. In this study, the heat distribution profiles at the surface and subsurface regions of human dentine samples irradiated with a Nd:YAG laser were simulated using Crank-Nicolson's finite difference method for different laser energies and pulse durations. Heat distribution throughout the dentin layer, from the external dentin surface to the pulp chamber wall, were calculated in each case, to investigate the details of pulsed laser-hard dental tissue interactions. The results showed that the final temperature at the pulp chamber wall and at the dentin surface are strongly dependent on the pulse duration, exposure time, and the energy contained in each pulse.

  17. Micromorphological and Chemical Approaches to Understand Changes in Ecological Functions of Metal-Impacted Soils under Various Land Uses

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    J. A. Acosta

    2011-01-01

    Full Text Available We investigated the changes in faunal activities as measures of the ecological functions of soils impacted by potentially toxic metals (PTMs under urban, industrial, agricultural, and natural uses. Concentrations and distributions of Zn, Cd, Pb, Cu, Mn, and Fe were estimated by sequential chemical extractions, while relicts and present faunal activities were studied by micromorphological analyses. Urban and natural lands were contaminated with Pb, Cd, and Zn. Microarthropods and fungi are observed to be active in the litter decomposition in natural, agricultural and urban lands which indicates that total concentration of PTMs in soils is not a good indicator to evaluate the limitations of PTMs to fauna activity. Metals immobilization on carbonates and Fe/Mn oxides, and fertilizations reduced the negative effects of metals on faunal activity. Micromorphological analyses showed the impacts of metal on soil ecological functions in industrial site, where the surface soils are devoid of any evidence of faunal activity; likely due to high proportion of Pb and Zn in organic components. Therefore, the impacts of metals in soil fauna activities, hence ecological functions of soils, are best evaluated by the knowledge of metal partitioning on solid phases in combination with observations of fauna activities using micromorphological techniques.

  18. Amalgam shear bond strength to dentin using different bonding agents.

    Science.gov (United States)

    Vargas, M A; Denehy, G E; Ratananakin, T

    1994-01-01

    This study evaluated the shear bond strength of amalgam to dentin using five different bonding agents: Amalgambond Plus, Optibond, Imperva Dual, All-Bond 2, and Clearfil Liner Bond. Flat dentin surfaces obtained by grinding the occlusal portion of 50 human third molars were used for this study. To contain the amalgam on the tooth surface, cylindrical plastic molds were placed on the dentin and secured with sticky wax. The bonding agents were then applied according to the manufacturers' instructions or light activated and Tytin amalgam was condensed into the plastic molds. The samples were thermocycled and shear bond strengths were determined using an Instron Universal Testing Machine. Analysis by one-way ANOVA indicated significant difference between the five groups (P < 0.05). The bond strength of amalgam to dentin was significantly higher with Amalgambond Plus using the High-Performance Additive than with the other four bonding agents.

  19. Analysis of anatomical and micromorphological characteristics of Iva xanthifolia nutt.

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    Krstić Lana N.

    2007-01-01

    Full Text Available Iva xanthifolia is a North American weed species, which was introduced and naturalized in Europe. Anatomical and micromorphological characteristics of this species were investigated, in order to get better knowledge of its biology, which could help in development of strategies for prevention of its spreading. Detailed descriptions of lamina, petiole, stem and inflorescence axis anatomical structures were given, together with micromorphological characteristics of epidermis and indumentum of lamina, petiole, stem, inflorescence axis, involucre and fruit. All vegetative organs had mesomorphic structure, with some xeromorphic adaptations. Mechanical tissue was well developed, which gave those plants additional strength and resistance. Trichomes were the most numerous on lamina and in the region of inflorescence, while rare on petiole and stem epidermis and their distribution varied according to plant organ.

  20. Association between Severity of Tooth Wear and Dentinal Hypersensitivity

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    Ashok Ayer

    2016-11-01

    Full Text Available Background & Objectives: Tooth wear (attrition, abrasion, erosion, and abfraction is perceived globally as ever increasing problem. Several outcome of the tooth wear are hypersensitivity, esthetic problems, functional impairment, annoyance to the patient, and fracture of the tooth. Among these, the measurable and more commonly reported outcome is hypersensitivity to stimuli. Although dentin hypersensitivity is a common clinical condition and is generally reported by the patient after experiencing a sharp, short pain caused by one of the several different external stimuli, it is often inadequately understood. None of the scientific literature available till date attempted to establish the relationship between tooth wear and dentin hypersensitivity which could be a key factor in monitoring those patients.  The aim of the study was to estimate the association between severity of teeth wear and sensitivity in the patients with reported dentinal hypersensitivity.Materials & Methods: Fifty patients with dentin hypersensitivity were investigated for tooth wear. Tooth wear measured using exact tooth wear index and level of sensitivity to stimuli was recorded using a numerical rating scale. Results: Enamel wear at cervical region of teeth showed a positive correlation (p=.010, similarly, dentin wear at cervical region of teeth showed positive correlation and significant association (p<.001 with dentinal hypersensitivity.Conclusion: The observation supports a significant association between severities of tooth surface wear and dentinal hypersensitivity.

  1. Characterization of Dentine to Assess Bond Strength of Dental Composites

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    Saad Liaqat

    2015-04-01

    Full Text Available This study was performed to develop alternating dentine adhesion models that could help in the evaluation of a self-bonding dental composite. For this purpose dentine from human and ivory was characterized chemically and microscopically before and after acid etching using Raman and SEM. Mechanical properties of dentine were determined using 3 point bend test. Composite bonding to dentine, with and without use of acid pre-treatment and/or the adhesive, were assessed using a shear bond test. Furthermore, micro gap formation after restoration of 3 mm diameter cavities in dentine was assessed by SEM. Initial hydroxyapatite level in ivory was half that in human dentine. Surface hydroxyapatites decreased by approximately half with every 23 s of acid etch. The human dentine strength (56 MPa was approximately double that of ivory, while the modulus was almost comparable to that of ivory. With adhesive use, average shear bond strengths were 30 and 26 MPa with and without acid etching. With no adhesive, average bond strength was 6 MPa for conventional composites. This, however, increased to 14 MPa with a commercial flowable “self–bonding” composite or upon addition of low levels of an acidic monomer to the experimental composite. The acidic monomer additionally reduced micro-gap formation with the experimental composite. Improved bonding and mechanical properties should reduce composite failures due to recurrent caries or fracture respectively.

  2. Dentin Hypersensitivity: Recent Concepts in Management

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    Vijay Mantri

    2011-01-01

    Full Text Available Tooth sensitivity is a very common clinical presentation which can cause considerable concern for patients. Dentin hypersensitivity (DH is characterized by short sharp pain arising from exposed dentin in response to stimuli. The most widely accepted theory of how the pain occurs is Brannstrom′s hydrodynamic theory, fluid movement within the dentinal tubules. The condition generally involves the facial surfaces of teeth near the cervical aspect and is very common in premolars and canines. This condition is frequently encountered by dentists, periodontists, hygienists and dental therapists. Some dental professionals lack confidence in treating DH. The management of this condition requires a good understanding of the complexity of the problem, as well as the variety of treatments available. This review considers the etiopathogenesis, incidence, diagnosis, prevention and management of dentinal hypersensitivity. DH is diagnosed after elimination of other possible causes of the pain. Any treatment plan for DH should include identifying and eliminating predisposing etiologic factors. Professionals should appreciate the role causative factors play in localizing and initiating hypersensitive lesions. It is important to identify these factors so that prevention can be included in the treatment plan. Treatments can be self-administered by the patient at home or be applied by a dental professional in the dental office. At-home methods tend to be simple and inexpensive and can treat simultaneously generalized DH affecting many teeth Desensitizing treatment should be delivered systematically, beginning with prevention and at-home treatments. The latter may be supplemented with in-office modalities.

  3. Efficacy of Modified Bioactive Glass for Dentin Remineralization and Obstruction of Dentinal Tubules

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    Mahshid Saffarpour

    2017-10-01

    Full Text Available Objectives: This study assessed the efficacy of modified bioactive glass (MBG for dentin remineralization and obstruction of dentinal tubules.Materials and Methods: Thirty-six dentin discs were made from 20 third molars and were stored in 12% lactic acid solution for two weeks to induce demineralization. The samples were divided into three groups (n=12: 1- BG, 2- BG modified with 5% strontium (Sr and 3- BG modified with 10% Sr. After applying the BG, the samples were stored in artificial saliva for 7, 14 and 21 days. Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR, X-ray Diffraction (XRD analysis, Scanning Electron Microscopy (SEM, and Energy-Dispersive X-ray (EDX analysis were used to assess remineralization. Also, 6 dentin discs were divided into three groups of BG, BG modified with 5% Sr and BG modified with 10% Sr, to examine tubular occlusion. The discs were etched using 0.5M of EDTA for two minutes and were stored in artificial saliva for 7 days. Changes in dentin surface morphology were evaluated under SEM.Results: Group 3 showed high rates of remineralization at days 7 and 14, although the rate decreased at day 21. Group 2 exhibited high rates of remineralization at days 7, 14 and 21. Dentinal tubules were partially occluded by BG and BG modified with 5% Sr, while they were almost completely obstructed after the use of BG modified with 10% Sr.Conclusions: Strontium increases remineralization. Addition of 10% Sr to BG enhances apatite formation; however, the apatite dissolves over time. Addition of 5% Sr to BG stabilizes the apatite lattice and increases the remineralization.

  4. Temperature rise produced by different light-curing units through dentin.

    Science.gov (United States)

    Yazici, A Rüya; Müftü, Ali; Kugel, Gerard

    2007-11-01

    This study investigated the temperature rise caused by different light curing units and the temperature increase in dentin of different thicknesses. Dentin discs of 1.0 and 2.0 mm thicknesses were prepared from extracted human mandibular molars. Temperatures were recorded directly at the surface of the light guide tip, under dentin discs with different thicknesses, and through a sandwich composed of 2 mm thick cured composite and dentin using a K-type thermocouple. The curing units used were two quartz-tungsten-halogen lights (Spectrum and Elipar Trilight-ET) and a light-emitting diode (LED). The highest temperature rise was observed under a Mylar strip using ET standard mode. Under 1 and 2 mm thick dentin barriers, the lowest temperature rise was measured for the LED curing light. Significant differences in temperature rise existed among all curing units except between the Spectrum and ET exponential modes under a 1 mm thick dentin barrier with cured composite. Temperature rises were insignificant between the Spectrum and ET exponential modes and between two modes of Trilight when the same experimental setup was used under a 2 mm thick dentin barrier. For all curing units, temperature elevation through 2 mm of dentin was less than for 1 mm of dentin thickness. The ET standard mode produced the highest and the LED produced the lowest temperature rise for all tested conditions. The thickness of dentin and light-curing unit might affect temperature transmission.

  5. Micromorphological characteristics of sandy forest soils recently impacted by wildfires in Russia

    Science.gov (United States)

    Maksimova, Ekaterina; Abakumov, Evgeny

    2017-04-01

    Two fire-affected soils were studied using micromorphological methods. The objective of the paper is to assess and compare fire effects on the micropedological organisation of soils in a forest-steppe zone of central Russia (Volga Basin, Togliatti city). Samples were collected in the green zone of Togliatti city. The results showed that both soils were rich in quartz and feldspar. Mica was highly present in soils affected by surface fires, while calcium carbonates were identified in the soils affected by crown fires. The type of plasma is humus-clay, but the soil assemblage is plasma-silt with a prevalence of silt. Angular and subangular grains are the most dominant soil particulates. No evidence of intensive weathering was detected. There was a decrease in the porosity of soils affected by fires as a consequence of soil pores filled with ash and charcoal.

  6. Bonding stability of adhesive systems to eroded dentin

    Directory of Open Access Journals (Sweden)

    Janaina Barros CRUZ

    2015-01-01

    Full Text Available This in vitro study evaluated the immediate and 6 months microshear bond strength (µSBS of different adhesive systems to sound and eroded dentin. Sixty bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces. Specimens were randomly allocated into two groups: sound dentin (immersion in artificial saliva and eroded dentin (erosive challenge following a pH cycling model comprising 4 ×/day Sprite Light® drink for 10 days. Then, specimens were reassigned according to the adhesive system: etch-and-rinse adhesive (Adper Single Bond, two-step self-etch system (Clearfil SE Bond, or one-step self-etch adhesive (Adper Easy One. Polyethylene tubes with an internal diameter of 0.76 mm were placed over pre-treated dentin and filled with resin composite (Z250. Half of the specimens were evaluated by the µSBS test after 24 h, and the other half 6 months later, after water storage at 37°C. Failure mode was evaluated using a stereomicroscope (400×. Data were analyzed by three-way repeated measures analysis of variance and Tukey’s post hoc tests (α = 0.05. After 6 months of water aging, marked reductions in µSBS values were observed, irrespective of the substrate. The µSBS values for eroded dentin were lower than those obtained for sound dentin. No difference in bonding effectiveness was observed among adhesive systems. For all groups, adhesive/mixed failure was observed. In conclusion, eroded dentin compromises the bonding quality of adhesive systems over time.

  7. Bond strength of compomers to dentin using acidic primers.

    Science.gov (United States)

    Tate, W H; You, C; Powers, J M

    1999-10-01

    To determine the in vitro bond strengths of seven compomer/bonding agent restorative systems to human dentin. Seven compomer/bonding agents were bonded to human dentin, stored in water at 37 degrees C for 24 hours, and debonded in tension. Bonding conditions were with and without phosphoric acid etching, with and without the use of combined primer/bonding agents, and under moist and wet bond interfaces. Without phosphoric acid etching, F2000/F2000 Compomer Primer/Adhesive and F2000/Single Bond Dental Adhesive System were less sensitive to dentin wetness. With moist dentin, bond strengths of Dyract/Prime & Bond 2.1, Dyract AP/Prime & Bond 2.1, Hytac/OSB light-curing, one-component bonding agent, F2000/Single Bond, and Freedom/STAE single component light-cured dentin/enamel adhesive system, were improved with phosphoric acid etching. Also, with moist dentin, the bond strength of F2000/F2000 Compomer Primer/Adhesive in the 3M Clicker dispensing system was higher without phosphoric acid etching, whereas bonds of Compoglass/Syntac Single-component were not affected by phosphoric acid etching. Bonding did not occur without primer/bonding agent, regardless of surface condition or use of phosphoric acid etching.

  8. A comparative microleakage evaluation of three different base materials in Class I cavity in deciduous molars in sandwich technique using dye penetration and dentin surface interface by scanning electron microscope

    Directory of Open Access Journals (Sweden)

    Babita Niranjan

    2016-01-01

    Full Text Available Introduction: A major objective in restorative dentistry is the control of marginal leakage, which may occur because of dimensional changes or lack of adaptation of restorative material to the cavity preparation. Numerous techniques have been advocated to overcome polymerization shrinkage in composite restorations. Aim and Objectives: This study investigated microleakage of three different bases under composite resin in sandwich technique using dye penetration and dentin surface interface using scanning electron microscope (SEM. Materials and Methods: Sixty extracted deciduous molars were stored in distilled water and Class I cavities with a width of about one-fourth of intercuspal distance and a depth of 0.5-1 mm below the dentino-enamel junction was prepared without bevels. In Group 1 - glass ionomer cement (GIC; Group 2 - mineral trioxide aggregate (MTA; Group 3 - Biodentine™ was placed as a base under composite. Teeth were longitudinally sectioned in two halves, through the centers of the restoration, immersed in 2% methylene blue and microleakage was evaluated under stereomicroscope and surface interface between base and dentin was evaluated under SEM. Results:Under the condition of in vitro study, less microleakage and less internal gaps were seen in Biodentine™ (0.00 ± 0.00 and 4.00 ± 1.59 group than MTA (0.00 ± 0.00 and 6.08 ± 1.82 and GIC (25.25 ± 6.57 and 14.73 ± 3.72, respectively and showed very strong positive correlation between microleakage and internal gaps. Conclusion: Biodentine™ exhibits superior marginal sealing ability as well as marginal adaptation under composite resin as compared to MTA and GIC.

  9. Shear bond strengths of three glass ionomer cements to enamel and dentine

    NARCIS (Netherlands)

    Carvalho, T.S.; van Amerongen, W.E.; de Gee, A.; Bönecker, M.; Sampaio, F.C.

    2011-01-01

    Objectives: The shear bond strength of three glass ionomer cements (GIC) to enamel and dentine was evaluated. Study Design: Sound permanent human molars (n=12) were grinded perpendicular to their axial axes, exposing smooth, flat enamel and dentine surfaces. The teeth were embedded in resin and

  10. Micromorphology of modern tills in southwestern Spitsbergen – insights into depositional and post-depositional processes

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    Skolasińska Katarzyna

    2016-12-01

    Full Text Available Textural properties and microstructures are commonly used properties in the analysis of Pleistocene and older glacial deposits. However, contemporary glacial deposits are seldom studied, particularly in the context of post-depositional changes. This paper presents the results of a micromorphological study of recently deposited tills in the marginal zones of Hansbreen and Torellbreen, glaciers in southwestern Spitsbergen. The main objectives of this study were to compare modern tills deposited in subglacial and supraglacial conditions, as well as tills that were freshly released from ice with those laid down several decades ago. The investigated tills are primarily composed of large clasts of metamorphic rocks and represent coarse-grained, matrix-supported diamictons. The tills reveal several characteristic features for ductile (e.g. turbate structures and brittle (e.g. lineations, microshears deformations, which have been considered to be indicative of subglacial conditions. In supraglacial tills, the same structures are common as in the subglacial deposits, which points to the preservation of the primary features, though the sediment was transferred up to the glacier surface due to basal ice layer deformation and redeposited as slumps, or to formation of similar structures due to short-distance sediment re-deposition by mass flows. This study revealed that it might not be possible to distinguish subglacial and supraglacial tills on the basis of micromorphology if the latter are derived from a subglacial position. The only noted difference was the presence of iron oxide cementation zones and carbonate dissolution features in supraglacial tills. These features were found in tills that were deposited at least a few years ago and are interpreted to be induced by early post-depositional processes involving porewater/sediment interactions.

  11. Experimental resin cements containing bioactive fillers reduce matrix metalloproteinase-mediated dentin collagen degradation.

    Science.gov (United States)

    Osorio, Raquel; Yamauti, Monica; Sauro, Salvatore; Watson, Thimoty F; Toledano, Manuel

    2012-09-01

    Collagen dentin matrix may represent a suitable scaffold to be remineralized in the presence of bioactive materials. The purpose of this study was to determine if experimental resin cements containing bioactive fillers may modulate matrix metalloproteinase-mediated collagen degradation of etched dentin. Human dentin beams demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (Sylc; OSspray Ltd, London, UK), and (3) resin with β-tricalcium phosphate-modified calcium silicate cement (HCAT-β) particles. The filler/resin ratio was 40/60 wt%. The specimens were stored in artificial saliva, and the determination of C-terminal telopeptide (ICTP) was performed by radioimmunoassay after 24 hours, 1 week, and 4 weeks. Scanning electron microscopic analysis of dentin surfaces after 4 weeks of storage was also executed. Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced the MMP activity in demineralized dentin. Resin-containing Bioglass 45S5 particles exerted higher and more stable protection of collagen at all tested dentin states and time points. HCAT-β induced collagen protection from MMPs only in EDTA-treated specimens. Dentin remineralization was achieved when dentin was infiltrated with the resin cements containing bioactive fillers. MMP degradation of dentin collagen is strongly reduced in resin-infiltrated dentin. The inclusion of Bioglass 45S5 particles exerted an additional protection of collagen during dentin remineralization. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Effect of a novel bioactive glass-ceramic on dentinal tubule occlusion: an in vitro study.

    Science.gov (United States)

    Zhong, Y; Liu, J; Li, X; Yin, W; He, T; Hu, D; Liao, Y; Yao, X; Wang, Y

    2015-03-01

    This in vitro study aimed to assess the ability and efficacy of HX-BGC, a novel bioactive glass-ceramic (SiO2-P2 O5-CaO-Na2 O-SrO), to reduce dentine tubule permeability. Dentine discs from human third molars were etched and randomly allocated into five groups: Group 1--distilled water; Group 2--Sensodyne Repair toothpaste (containing NovaMin®); Group 3--HX-BGC toothpaste (containing 7.5% HX-BGC); Group 4--control toothpaste (without HX-BGC); and Group 5--HX-BGC powder. Specimens were treated daily by brushing with an electric toothbrush for 20 seconds. Between daily treatments (7 days total), specimens were immersed in artificial saliva for 24 hours. Dentine permeability was measured at baseline, after the first treatment, after the first 24-hour immersion in artificial saliva and at the end of day 7. Dentine morphology and surface deposits were observed by scanning electron microscopy after one day and 7 days of treatment, respectively. Sensodyne Repair and bioactive glass-ceramic toothpaste significantly and immediately lowered dentine permeability. The HX-BGC powder group showed the highest reduction in dentine permeability after 7 days of treatment. The novel bioactive glass-ceramic material HX-BGC is effective in reducing dentine permeability by occluding open dentine tubules, indicating that HX-BGC may be a potential treatment for dentine hypersensitivity. © 2015 Australian Dental Association.

  13. Effect of Structure, Composition, and Micromorphology on the Hydrophobic Property of F-DLC Film

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    Aihua Jiang

    2013-01-01

    Full Text Available Fluorinated diamond-like carbon (F-DLC films were prepared by radio frequency plasma-enhanced chemical vapor deposition technique with CF4 and CH4 as source gases under different deposition conditions. The chemical bonding structure and composition of the films were detected by Raman, Fourier transform infrared absorption spectrometry (FTIR, and X-ray photoelectron spectroscopy (XPS characterization. The micromorphology and surface roughness of the film were observed and analyzed by atomic force microscopy (AFM. The results indicated that all the prepared films presented a diamond-like carbon structure. The relative content of fluorine in the films increased, containing more CF2 groups. The ratio of hybrid structure sp3/sp2 decreased. The surface roughness of the films increased when the gas flow ratio R (R = CF4/[CH4 + CF4] or the deposition power increased. The contact angle of water with the surface of the F-DLC film was measured with a static drop-contact angle/surface tension measuring instrument. The hydrophobic property of the F-DLC films was found to be dependent on the sp2 structure, fluorine content, and surface roughness of the films. The contact angle increased when the relative content of fluorine in the films and sp2 content increased, whereas the contact angle first increased and then decreased with the surface roughness.

  14. Influence of two different template removal methods on the micromorphology, crystal structure, and photocatalytic activity of hollow CdS nanospheres

    International Nuclear Information System (INIS)

    Wang, Han; Jin, Tingting; Zheng, Xing; Jiang, Bo; Zhu, Chaosheng; Yuan, Xiangdong; Zheng, Jingtang; Wu, Mingbo

    2016-01-01

    Hollow cadmium sulfide (CdS) nanospheres of about 260 nm average diameters and about 30 nm shell thickness can be easily synthesized via a sonochemical process, in which polystyrene (PS) nanoparticles were employed as templates. In order to remove the PS templates, both etching and calcination were applied in this paper. The influence of the two different template removal methods on the surface micromorphology, crystal structure, and photocatalytic activity of hollow CdS nanospheres was carefully performed a comparative study. Results of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray, FT-IR, thermogravimetric analysis, Brunauer–Emmett–Teller, diffused reflectance spectra, and decolorization experiments showed that the different template removal methods exhibited a significant influence on the surface micromorphology, crystal structure, and photocatalytic activity of hollow CdS nanospheres. The CdS hollow nanospheres as-prepared by etching had pure cubic sphalerite structure, higher –OH content, less defects and exhibited good photocatalytic activity for rhodamine-B, Methylene Blue and methyl orange under UV–vis light irradiation. However, CdS hollow nanospheres obtained by calcination with a hexagonal crystal structure, less –OH content, more defects have shown worse photocatalytic activity. This indicated that surface micromorphology and crystalline phase were mainly factors influencing photocatalytic activity of hollow CdS nanospheres.

  15. Influence of two different template removal methods on the micromorphology, crystal structure, and photocatalytic activity of hollow CdS nanospheres

    Science.gov (United States)

    Wang, Han; Jin, Tingting; Zheng, Xing; Jiang, Bo; Zhu, Chaosheng; Yuan, Xiangdong; Zheng, Jingtang; Wu, Mingbo

    2016-11-01

    Hollow cadmium sulfide (CdS) nanospheres of about 260 nm average diameters and about 30 nm shell thickness can be easily synthesized via a sonochemical process, in which polystyrene (PS) nanoparticles were employed as templates. In order to remove the PS templates, both etching and calcination were applied in this paper. The influence of the two different template removal methods on the surface micromorphology, crystal structure, and photocatalytic activity of hollow CdS nanospheres was carefully performed a comparative study. Results of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray, FT-IR, thermogravimetric analysis, Brunauer-Emmett-Teller, diffused reflectance spectra, and decolorization experiments showed that the different template removal methods exhibited a significant influence on the surface micromorphology, crystal structure, and photocatalytic activity of hollow CdS nanospheres. The CdS hollow nanospheres as-prepared by etching had pure cubic sphalerite structure, higher -OH content, less defects and exhibited good photocatalytic activity for rhodamine-B, Methylene Blue and methyl orange under UV-vis light irradiation. However, CdS hollow nanospheres obtained by calcination with a hexagonal crystal structure, less -OH content, more defects have shown worse photocatalytic activity. This indicated that surface micromorphology and crystalline phase were mainly factors influencing photocatalytic activity of hollow CdS nanospheres.

  16. Influence of two different template removal methods on the micromorphology, crystal structure, and photocatalytic activity of hollow CdS nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Han; Jin, Tingting [China University of Petroleum, State Key Laboratory of Heavy Oil Processing (China); Zheng, Xing, E-mail: znhk113@163.com [Beijing ZNHK Science and Technology Development Co., Ltd. (China); Jiang, Bo; Zhu, Chaosheng [China University of Petroleum, State Key Laboratory of Heavy Oil Processing (China); Yuan, Xiangdong [Baotou Light Industry and Vocational Technical College (China); Zheng, Jingtang, E-mail: jtzheng03@163.com; Wu, Mingbo [China University of Petroleum, State Key Laboratory of Heavy Oil Processing (China)

    2016-11-15

    Hollow cadmium sulfide (CdS) nanospheres of about 260 nm average diameters and about 30 nm shell thickness can be easily synthesized via a sonochemical process, in which polystyrene (PS) nanoparticles were employed as templates. In order to remove the PS templates, both etching and calcination were applied in this paper. The influence of the two different template removal methods on the surface micromorphology, crystal structure, and photocatalytic activity of hollow CdS nanospheres was carefully performed a comparative study. Results of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray, FT-IR, thermogravimetric analysis, Brunauer–Emmett–Teller, diffused reflectance spectra, and decolorization experiments showed that the different template removal methods exhibited a significant influence on the surface micromorphology, crystal structure, and photocatalytic activity of hollow CdS nanospheres. The CdS hollow nanospheres as-prepared by etching had pure cubic sphalerite structure, higher –OH content, less defects and exhibited good photocatalytic activity for rhodamine-B, Methylene Blue and methyl orange under UV–vis light irradiation. However, CdS hollow nanospheres obtained by calcination with a hexagonal crystal structure, less –OH content, more defects have shown worse photocatalytic activity. This indicated that surface micromorphology and crystalline phase were mainly factors influencing photocatalytic activity of hollow CdS nanospheres.

  17. Effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin.

    Science.gov (United States)

    Singh, Payal; Nagpal, Rajni; Singh, Udai Pratap

    2017-08-01

    This in vitro study evaluated the effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin. Flat coronal dentin surfaces were prepared in 120 extracted human molars. Teeth were randomly divided into 5 groups ( n = 24) according to 5 different surface pre-treatments: No pre-treatment (control); 1M carbodiimide (EDC); 0.1% epigallocatechin-3-gallate (EGCG); 2% minocycline (MI); 10% sodium ascorbate (SA). After surface pre-treatment, adhesive (Adper Single Bond 2 [SB], 3M ESPE) was applied. Composite was applied into transparent plastic tubes (2.5 mm in diameter), which was placed over the bonded dentin surface. From each group, 10 samples were subjected to shear bond strength (SBS) evaluation at 24 hours (immediate) and remaining 10 samples were tested after 6 months (delayed). Additionally, 4 samples per group were subjected to scanning electron microscopic analysis for observation of resin-dentin interface. The data were statistically analysed with Shaperio‑Wilk W test, 2-way analysis of variance (ANOVA), and post hoc Tukey's test. At 24 hours, SBS of all surface pre-treatment groups were comparable with the control group, with significant differences found between EDC and SA groups only ( p = 0.009). After 6 months storage, EDC, EGCG, and MI pre-treatments preserved the resin-dentin bond strength with no significant fall. Dentin pre-treatment with all the dentin biomodifiers except SA resulted in significant preservation of resin-dentin bond over 6 months storage period, without negatively affecting the immediate bond strength of the etch and rinse adhesive tested.

  18. Effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin

    Directory of Open Access Journals (Sweden)

    Payal Singh

    2017-07-01

    Full Text Available Objectives This in vitro study evaluated the effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin. Materials and Methods Flat coronal dentin surfaces were prepared in 120 extracted human molars. Teeth were randomly divided into 5 groups (n = 24 according to 5 different surface pre-treatments: No pre-treatment (control; 1M carbodiimide (EDC; 0.1% epigallocatechin-3-gallate (EGCG; 2% minocycline (MI; 10% sodium ascorbate (SA. After surface pre-treatment, adhesive (Adper Single Bond 2 [SB], 3M ESPE was applied. Composite was applied into transparent plastic tubes (2.5 mm in diameter, which was placed over the bonded dentin surface. From each group, 10 samples were subjected to shear bond strength (SBS evaluation at 24 hours (immediate and remaining 10 samples were tested after 6 months (delayed. Additionally, 4 samples per group were subjected to scanning electron microscopic analysis for observation of resin-dentin interface. The data were statistically analysed with Shaperio‑Wilk W test, 2-way analysis of variance (ANOVA, and post hoc Tukey's test. Results At 24 hours, SBS of all surface pre-treatment groups were comparable with the control group, with significant differences found between EDC and SA groups only (p = 0.009. After 6 months storage, EDC, EGCG, and MI pre-treatments preserved the resin-dentin bond strength with no significant fall. Conclusions Dentin pre-treatment with all the dentin biomodifiers except SA resulted in significant preservation of resin-dentin bond over 6 months storage period, without negatively affecting the immediate bond strength of the etch and rinse adhesive tested.

  19. Shear Bond Strength of Composite to Nd-YAG Lased Dentin with and without Dye

    Directory of Open Access Journals (Sweden)

    H. Kermanshah

    2004-06-01

    Full Text Available Statement of Problem: The achievement of a good and durable dentin/composite resin bond is an important task in restorative dentistry. The application of acid conditioners and dentin bonding agents is an accepted method to enhance this bond strength. Pretreating of dentin surface by laser irradiation seems to be a supplemental way to obtain better results,since lased dentin is more roughened and has a widest surface area to interact with acidconditioner.Purpose: In this study, the effect of dentin surface pretreating by Nd-YAG laser on dentin/composite shear bond strength was examined. Moreover, the effect of Chinese ink as a surface energy absorber on this value was investigated.Methods and Materials: Thirty-nine freshly extracted human teeth without dentinal caries were collected and their occlusal dentins were exposed using a diamond disk. The collected samples were divided into three identical groups. The dentin surface of the first group was lased by an Nd-YAG pulsed laser (100 mJ, 20 Hz through a 320 mm fiber optic in a swiping movement. In the second group, 10% solution of Chinese ink was applied on the dentinal surface before lasing. The samples of the third group were not lased at all. Thedentinal surface prepared by 35% phosphoric acid and Scotchbond MP primer and adhesive. Then, composite resin was cured on dentinal surface. After incubation, in water at 37°C for 24 hours, the samples were tested by Digital Tritest ELE machine.Results: The values of bond strength were 20.83±3.96 MPa, 17.83±3.63 MPa and 19.38±4.88 MPa for the lased, unlased and dye-enhanced groups, respectively. The results were not significant by ANOVA test (a=0.05. Although in the Weiboul modulus, the lased group offered better bond strength.Conclusion: Further studies are required to determine whether chemical as well as physical alterations to the dentin surface are induced by laser etching, and whether these influence the performance of the range of dentin

  20. The effect of air thinning on dentin adhesive bond strength.

    Science.gov (United States)

    Hilton, T J; Schwartz, R S

    1995-01-01

    The purpose of this study was to determine if air thinning three dentin adhesives would affect bond strength to dentin. Ninety human molars were mounted in acrylic and the occlusal surfaces ground to expose a flat dentin surface. Thirty teeth were randomly assigned to one of the following dentin bonding agent/composite combinations: A) Universal Bond 3/TPH (Caulk), B) All-Bond 2/Bis-Fil-P (Bisco), and C) Scotchbond Multi-Purpose/Z-100 (3m). The primers were applied following the manufacturers' instructions. The adhesives were applied by two methods. A thin layer of adhesive was applied with a brush to 15 specimens in each group and light cured. Adhesive was brushed on to the remaining 15 teeth in the group, air thinned for 3 seconds, and then polymerized. The appropriate composite was applied in 2 mm increments and light cured utilizing a 5 mm-in-diameter split Teflon mold. Following 3 months of water storage, all groups were shear tested to failure on an Instron Universal Testing Machine. Bond strength was significantly higher in all groups when the dentin bonding agent was painted on without being air thinned. Scotchbond Multi-Purpose had significantly higher bond strength than All-Bond 2, which had significantly higher bond strength than Universal Bond 3.

  1. Functional remineralization of carious dentin

    Science.gov (United States)

    Pugach, Megan Kardon

    A primary goal of dental tissue engineering is the biological reconstruction of tooth substrate destroyed by caries or other diseases affecting tooth mineralization. Traditionally, dentists treat caries by using invasive techniques to remove the diseased dental tissue and restore the lesion, ideally preventing further progression of decay. Success in strategies associated with remineralization of enamel and root caries have contributed to the less invasive prospect of remineralization of dentinal carious lesions. The central hypothesis of this dissertation is that carious dentin lesions can be remineralized if the lesions contain residual mineral. Caries Detector (CD) stained zones (pink, light pink, transparent and normal) of arrested carious dentin lesions were characterized according to microstructure by atomic force microscopy (AFM) imaging, mineral content by digital transverse microradiography, and nanomechanical properties by AFM-based nanoindentation. CD-stained and unstained zones had significantly different microstructure, mineral content and nanomechanical properties. Furthermore, the most demineralized carious zone contained residual mineral. To obtain reproducible, standardized dentin caries lesions, we characterized the lesions from an artificial carious dentin lesion model using a 0.05M acetate demineralization buffer. The artificial caries-like lesions produced by the buffer had similar mineral content and nanomechanical properties in the stained and unstained zones as natural dentin lesions. Both natural and artificial lesions had significant correlations between mineral content and nanomechanical properties. Mineral crystallite size and shape was examined by small angle x-ray scattering. Both natural and artificial carious dentin had different mineral sizes than normal dentin. Collagen in natural and artificial carious dentin lesions was examined by trichrome stain, AFM high-resolution imaging, and UV resonance Raman spectroscopy, to determine if

  2. Polymer Nanocarriers for Dentin Adhesion

    Science.gov (United States)

    Osorio, R.; Osorio, E.; Medina-Castillo, A.L.; Toledano, M.

    2014-01-01

    To obtain more durable adhesion to dentin, and to protect collagen fibrils of the dentin matrix from degradation, calcium- and phosphate-releasing particles have been incorporated into the dental adhesive procedure. The aim of the present study was to incorporate zinc-loaded polymeric nanocarriers into a dental adhesive system to facilitate inhibition of matrix metalloproteinases (MMPs)-mediated collagen degradation and to provide calcium ions for mineral deposition within the resin-dentin bonded interface. PolymP-nActive nanoparticles (nanoMyP) were zinc-loaded through 30-minute ZnCl2 immersion and tested for bioactivity by means of 7 days’ immersion in simulated body fluid solution (the Kokubo test). Zinc-loading and calcium phosphate depositions were examined by scanning and transmission electron microscopy, elemental analysis, and x-ray diffraction. Nanoparticles in ethanol solution infiltrated into phosphoric-acid-etched human dentin and Single Bond (3M/ESPE) were applied to determine whether the nanoparticles interfered with bonding. Debonded sticks were analyzed by scanning electron microscopy. A metalloproteinase collagen degradation assay was also performed in resin-infiltrated dentin with and without nanoparticles, measuring C-terminal telopeptide of type I collagen (ICTP) concentration in supernatants, after 4 wk of immersion in artificial saliva. Numerical data were analyzed by analysis of variance (ANOVA) and Student-Newman-Keuls multiple comparisons tests (p calcium regardless of zinc incorporation. Nanoparticles failed to infiltrate demineralized intertubular dentin and remained on top of the hybrid layer, without altering bond strength. Calcium and phosphorus were found covering nanoparticles at the hybrid layer, after 24 h. Nanoparticle application in etched dentin also reduced MMP-mediated collagen degradation. Tested nanoparticles may be incorporated into dental adhesive systems to provide the appropriate environment in which dentin MMP

  3. Effect of Dentin Wetness on the Bond Strength of Universal Adhesives

    Directory of Open Access Journals (Sweden)

    An-Na Choi

    2017-10-01

    Full Text Available The effects of dentin wetness on the bond strength and adhesive interface morphology of universal adhesives have been investigated using micro-tensile bond strength (μTBS testing and confocal laser scanning microscopy (CLSM. Seventy-two human third molars were wet ground to expose flat dentin surfaces. They were divided into three groups according to the air-drying time of the dentin surfaces: 0 (without air drying, 5, and 10 s. The dentin surfaces were then treated with three universal adhesives: G-Premio Bond, Single Bond Universal, and All-Bond Universal in self-etch or etch-and-rinse mode. After composite build up, a μTBS test was performed. One additional tooth was prepared for each group by staining the adhesives with 0.01 wt % of Rhodamine B fluorescent dye for CLSM analysis. The data were analyzed statistically using ANOVA and Tukey’s post hoc tests (α = 0.05. Two-way ANOVA showed significant differences among the adhesive systems and dentin moisture conditions. An interaction effect was also observed (p < 0.05. One-way ANOVA showed that All-Bond Universal was the only material influenced by the wetness of the dentin surfaces. Wetness of the dentin surface is a factor influencing the micro-tensile bond strength of universal adhesives.

  4. Micromorphological Studies of the Loranthaceae, Phragmanthera capitata (Sprengel Balle

    Directory of Open Access Journals (Sweden)

    Franklin Uangbaoje Ohikhena

    2017-01-01

    Full Text Available Phragmanthera capitata (Sprengel Balle is a mistletoe of the Loranthaceae family that has been explored for its therapeutic properties in folklore for ages. However, there had been an alarming increase in misidentification of species in this family. This may be due in part to the lack of species taxonomic information. Hence, this study wishes to highlight the range of micromorphological features which could complement the information database of this species. Scanning electron, light, and energy dispersive X-ray (EDX microscopies were used for this study. The result revealed a paracytic type of stomata with mean abaxial and adaxial density of 225.42±3.67 mm2 and 137.21±5.65 mm2, respectively, and mean guard cell length of 26.45±0.02 μm. Oval-shaped lenticels with a mean length of 34.29±0.26 μm were observed. They were arranged in parallel on the epidermal cells of the abaxial midrib. Densely packed stellate trichomes were revealed on the abaxial epidermis with a density of 63.32±3.70 mm2. Tracheary elements, which are tightly packed with granules believed to be proteins, were observed in the cross sections of the twig. Deposits chiefly composed of silicon, aluminium, potassium, and iron were recorded in the EDX analysis. This study revealed detailed descriptive micromorphological structures which could serve as a source of information and reference for the taxonomic description of P. capitata.

  5. Penetration pattern of rhodamine dyes into enamel and dentin: confocal laser microscopy observation.

    Science.gov (United States)

    Kwon, S R; Wertz, P W; Li, Y; Chan, D C N

    2012-02-01

    Enamel and dentin are susceptible to extrinsic and intrinsic stains. The purposes of this study were to determine the penetration pattern of Rhodamine B and dextran-conjugated Rhodamine B into the enamel and dentin as observed by confocal laser microscopy and to relate it to the penetration pattern of hydrogen peroxide commonly used as an active ingredient in tooth-whitening agents and high-molecular-weight staining molecules. Eighteen recently extracted human maxillary anterior teeth were used. Teeth were cleaned and painted with nail varnish except for the crown area above the cemento-enamel junction (CEJ). The painted teeth were then immersed in Rhodamine B and dextran-conjugated Rhodamine B (70 000 MW) for 4, 7, 10 and 15 days. Teeth were sliced to 3 mm thickness in transverse plane and mounted on a glass slide just prior to observation with confocal laser microscopy. Rhodamine B and dextran-conjugated Rhodamine B readily penetrated into the enamel and dentin when exposed for 4 and 7 days, respectively. Rhodamine B penetrated along the interprismatic spaces of the enamel into the dentin. The penetration was accentuated in sections with existing crack lines in the enamel. Rhodamine B was readily absorbed into the dentinal tubules at the dentino-enamel junction and continued to penetrate through the dentin via the dentinal tubules into the pre-dentin. Within the limitations of this study, it is concluded that Rhodamine B and dextran-conjugated Rhodamine B when applied to the external surface of the tooth readily penetrate into the enamel and dentin via the interprismatic spaces in the enamel and dentinal tubules in the dentin, suggesting that stain molecules and bleaching agents possibly exhibit similar penetration pathways. © 2011 The Authors. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  6. Enamel and dentin bond strength following gaseous ozone application.

    Science.gov (United States)

    Cadenaro, Milena; Delise, Chiara; Antoniollo, Francesca; Navarra, Ottavia Chiara; Di Lenarda, Roberto; Breschi, Lorenzo

    2009-08-01

    To evaluate the effects of gaseous ozone application on enamel and dentin bond strength produced by two self-etching adhesive systems. The shear bond strength test was conducted to assess adhesion on enamel (protocol 1), while the microtensile bond strength test was performed on dentin (protocol 2). Protocol 1: 96 bovine incisors were randomly divided into 4 groups, and enamel surfaces were bonded in accordance with the following treatments: (1E) ozone + Clearfil Protect Bond; (2E) Clearfil Protect Bond (control); (3E) ozone + Xeno III; (4E) Xeno III (control). Ozone gas was applied for 80 s. Shear bond strength was measured with a universal testing machine. Protocol 2: 40 noncarious human molars were selected. Middle/deep dentin was exposed and bonded in accordance with the following treatments: (1D) ozone+Clearfil Protect Bond; (2D) Clearfil Protect Bond (control); (3D) ozone+Xeno III (4D) Xeno III (control). Four-mm-thick buildups were built on the adhesives, then specimens were sectioned in accordance with the nontrimming technique. Specimens were stressed until failure occurred, and failure modes were analyzed. Shear bond and microtensile bond strength data were analyzed using two-way ANOVA and Tukey's post-hoc test. No statistical differences were found between ozone treated specimens and controls, neither on enamel nor on dentin irrespective of the tested adhesive. Clearfil Protect Bond showed higher bond strength to enamel than Xeno III, irrespective of the ozone treatment (p enamel and dentin bond strength.

  7. Effect of sonic application mode on the resin-dentin bond strength and dentin permeability of self-etching systems.

    Science.gov (United States)

    Mena-Serrano, Alexandra; Costa, Thays Regina Ferreira da; Patzlaff, Rafael Tiago; Loguercio, Alessandro Dourado; Reis, Alessandra

    2014-10-01

    To compare manual and sonic adhesive application modes in terms of the permeability and microtensile bond strength of a self-etching adhesive applied in the one-step or two-step protocol. Self-etching All Bond SE (Bisco) was applied as a one- or a two-step adhesive under manual or sonic vibration modes on flat occlusal dentin surfaces of 64 human molars. Half of the teeth were used to measure the hydraulic conductance of dentin at 200 cm H₂O hydrostatic pressure for 5 min immediately after the adhesive application. In the other half, composite buildups (Opallis) were constructed incrementally to create resin-dentin sticks with a cross-sectional area of 0.8 mm² to be tested in tension (0.5 mm/min) immediately after restoration placement. Data were analyzed using a two-way ANOVA and Tukey's test (α = 0.05). The fluid conductance of dentin was significantly reduced by the sonic vibration mode for both adhesives, but no effect on the bond strength values was observed for either adhesive. The sonic application mode at an oscillating frequency of 170 Hz can reduce the fluid conductance of the one- and two-step All Bond SE adhesive when applied on dentin.

  8. Dentin Permeability of Carious Primary Teeth

    African Journals Online (AJOL)

    primary dental pulp make it difficult to determine which modality offers the best ... The most common pathology of the dentine is dental caries. ... to evaluate dentine permeability is to calculate its hydraulic conductance (Lp) using fluid filtration ...

  9. Papain-based gel for biochemical caries removal: influence on microtensile bond strength to dentin

    Directory of Open Access Journals (Sweden)

    Evandro Piva

    2008-12-01

    Full Text Available This study investigated the influence of a papain-based gel (Papacárie for chemo-mechanical caries removal on bond strength to dentin. Human molars were assigned to the following groups: Group 1: sound teeth were flattened to expose dentin; Group 2: after flattening of surfaces, the papain-based gel was applied on the sound dentin; Group 3: overlying enamel from carious teeth was removed and mechanical excavation of dentin was conducted; Group 4: chemo-mechanical excavation of carious dentin was conducted using the papain-based gel. The Prime&Bond NT or Clearfil SE Bond adhesive systems were used for restorative procedures. A microtensile bond strength test was performed, and the modes of failure were determined under SEM. The data were submitted to two-way ANOVA and Tukey's test (p < 0.05. No significant differences were observed between the sound dentin groups. For both excavation methods, Clearfil presented a significantly higher bond strength than Prime&Bond NT. Also, for Clearfil, the mechanically excavated samples disclosed a significantly higher bond strength than the chemo-mechanically ones. For Prime&Bond NT, no significant differences were detected between the excavation methods. Predominance of mixed failures for the sound substrate and of adhesive failures for the carious dentin one was detected. The bond strength to carious dentin of the self-etching system was negatively affected by chemo-mechanical excavation using the papain-based gel.

  10. Eroded dentin does not jeopardize the bond strength of adhesive restorative materials

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    Janaina Barros Cruz

    2012-08-01

    Full Text Available This in vitro study evaluated the bond strength of adhesive restorative materials to sound and eroded dentin. Thirty-six bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces. Specimens were randomly allocated in 2 groups: sound dentin (immersion in artificial saliva and eroded dentin (pH cycling model - 3× / cola drink for 7 days. Specimens were then reassigned according to restorative material: glass ionomer cement (KetacTM Molar Easy Mix, resin-modified glass ionomer cement (VitremerTM or adhesive system with resin composite (Adper Single Bond 2 + Filtek Z250. Polyethylene tubes with an internal diameter of 0.76 mm were placed over the dentin and filled with the material. The microshear bond test was performed after 24 h of water storage at 37ºC. The failure mode was evaluated using a stereomicroscope (400×. Bond strength data were analyzed with two-way ANOVA and Tukey's post hoc tests (α = 0.05. Eroded dentin showed bond strength values similar to those for sound dentin for all materials. The adhesive system showed the highest bond strength values, regardless of the substrate (p < 0.0001. For all groups, the adhesive/mixed failure prevailed. In conclusion, adhesive materials may be used in eroded dentin without jeopardizing the bonding quality. It is preferable to use an etch-and-rinse adhesive system because it shows the highest bond strength values compared with the glass ionomer cements tested.

  11. Physicochemical Properties, Micromorphology and Clay Mineralogy of Soils Affected by Geological Formations, Geomorphology and Climate

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    A. Bayat

    2017-01-01

    Full Text Available Introduction: Soil genesis and development in arid and semi-arid areas are strongly affected by geological formations and geomorphic surfaces. Various morphological, physical, and geochemical soil properties at different geomorphic positions are usually attributed to different soil forming factors including parent material and climate. Due to variations in climate, geological formations (Quaternary, Neogene and Cretaceous and geomorphology, the aim of the present research was the study of genesis, development, clay mineralogy, and micromorphology of soils affected by climate, geology and geomorphology in Bardsir area, Kerman Province. Materials and Methods: The study area, 25000 ha, starts from Bardsir and extends to Khanesorkh elevations close to Sirjan city. The climate of the area is warm and semi-arid with mean annual temperature and precipitation of 14.9 °C and 199 mm, respectively. Soil moisture and temperature regimes of the area are aridic and mesic due to 1:2500000 map, provided by Soil and Water Research Institute. Moving to west and southwest, soil moisture regime of the area changes to xeric with increasing elevation. Using topography and geology maps (1:100000 together with Google Earth images, geomorphic surfaces and geologic formations of the area were investigated. Mantled pediment (pedons 1, 3, 7, and 8, rock pediment (pedon 2, semi-stable alluvial plain (pedon 6, unstable alluvial plain (pedon 5, piedmont plain (pedons 9 and 11, intermediate surface of alluvial plain and pediment (pedon 4, and old river terrace (pedon 10 are among geomorphic surfaces investigated in the area. Mantled pediment is composed of young Quaternary sediments and Cretaceous marls. Rock pediments are mainly formed by Cretaceous marls. Quaternary formations are dominant in alluvial plains. Alluvial terraces and intermediate surface of alluvial plain and pediment are dominated by Neogene conglomerates. Siltstone, sandstone, and Neogene marls together with

  12. Improved reactive nanoparticles to treat dentin hypersensitivity.

    Science.gov (United States)

    Toledano-Osorio, Manuel; Osorio, Estrella; Aguilera, Fátima S; Luis Medina-Castillo, Antonio; Toledano, Manuel; Osorio, Raquel

    2018-05-01

    The aim of this study was to evaluate the effectiveness of different nanoparticles-based solutions for dentin permeability reduction and to determine the viscoelastic performance of cervical dentin after their application. Four experimental nanoparticle solutions based on zinc, calcium or doxycycline-loaded polymeric nanoparticles (NPs) were applied on citric acid etched dentin, to facilitate the occlusion and the reduction of the fluid flow at the dentinal tubules. After 24 h and 7 d of storage, cervical dentin was evaluated for fluid filtration. Field emission scanning electron microscopy, energy dispersive analysis, AFM and Nano-DMA analysis were also performed. Complex, storage, loss modulus and tan delta (δ) were assessed. Doxycycline-loaded NPs impaired tubule occlusion and fluid flow reduction trough dentin. Tubules were 100% occluded in dentin treated with calcium-loaded NPs or zinc-loaded NPs, analyzed at 7 d. Dentin treated with both zinc-NPs and calcium-NPs attained the highest reduction of dentinal fluid flow. Moreover, when treating dentin with zinc-NPs, complex modulus values attained at intertubular and peritubular dentin were higher than those obtained after applying calcium-NPs. Zinc-NPs are then supposed to fasten active dentin remodeling, with increased maturity and high mechanical properties. Zinc-based nanoparticles are then proposed for effective dentin remineralization and tubular occlusion. Further research to finally prove for clinical benefits in patients with dentin hypersensitivity using Zn-doped nanoparticles is encouraged. Erosion from acids provokes dentin hypersensitivity (DH) which presents with intense pain of short duration. Open dentinal tubules and demineralization favor DH. Nanogels based on Ca-nanoparticles and Zn-nanoparticles produced an efficient reduction of fluid flow. Dentinal tubules were filled by precipitation of induced calcium-phosphate deposits. When treating dentin with Zn-nanoparticles, complex modulus

  13. The effect of Er:YAG laser irradiation on the bond stability of self-etch adhesives at different dentin depths.

    Science.gov (United States)

    Karadas, Muhammet; Çağlar, İpek

    2017-07-01

    The aim of this study was to evaluate the effect of Er:YAG laser irradiation on the micro-shear bond strength of self-etch adhesives to the superficial dentin and the deep dentin before and after thermocycling. Superficial dentin and deep dentin surfaces were prepared by flattening of the occlusal surfaces of extracted human third molars. The deep or superficial dentin specimens were randomized into three groups according to the following surface treatments: group I (control group), group II (Er:YAG laser; 1.2 W), and group III (Er:YAG laser; 0.5 W). Clearfil SE Bond or Clearfil S 3 Bond was applied to each group's dentin surfaces. After construction of the composite blocks on the dentin surface, the micro-shear bond testing of each adhesive was performed at 24 h or after 15,000 thermal cycles. The data were analyzed using a univariate analysis of variance and Tukey's test (p  0.05). However, deep-dentin specimens irradiated with laser showed significantly higher bond strengths than did control specimens after thermocycling (p adhesives may be altered by the dentin depth. Regardless of the applied surface treatment, deep dentin showed significant bond degradation.

  14. Evaluation of inactivation of intracanal antiseptics by dentin, demineralized dentin, dentin matrix and mineral component of dentin

    Directory of Open Access Journals (Sweden)

    Razmi H

    2007-01-01

    Full Text Available Background and Aim: Many studies have shown that microorganisms are the main cause of pulpal diseases and the main purpose of root canal therapy is their elimination from the root canal system. Antiseptic agents are used to reduce bacteria but their antibacterial activities differ from in vivo to in vitro studies and might be inactivated by dentin and its components in root canal space. This study was designed to investigate the effect of dentin on antibacterial activity of different antimicrobial agents. Materials and Methods: In this experimental study, two antibacterial agents (sodium hypochlorite and chlorhexidine with different concentrations were used in four experimental groups: Group 1: dentin, Group 2: demineralized dentin with EDTA, Group 3: dentin matrix and Group 4: dentin mineral component. The species used in this study was Entrococcus faecalis. Different concentration of agents were added to mixture of each experimental group and bacteria. At the baseline and after one and 24 hours, samples were collected and cultured. After incubation period, colonies were counted. Data were analyzed by Tukey test with p<0.05 as the limit of significance. Results: 2% and 0.2% chlorhexidine, and 5% sodium hypochlorite solutions at the three studied times eliminated Entrococcus faecalis completely. 1% sodium hypochlorite eliminated all bacteria in 1h and 24 hs. Statistical analysis showed significant differences between experimental and control groups (P<0.05. Sodium 1% hypochlorite at time 0, could reduce bacteria significantly (P<0.05 but didn’t eliminate them completely. Conclusion: Inactivation of intracanal antiseptics was not observed in this study. As elimination of bacteria occurred, application of these antibacterial agents are recommended in endodontic treatment. Further investigations on other antibacterial agents, other concentrations and shorter time intervals are recommended.

  15. In Vitro Study of Dentin Hypersensitivity Treated by 980-nm Diode Laser.

    Science.gov (United States)

    Liu, Ying; Gao, Jie; Gao, Yan; Xu, Shuaimei; Zhan, Xueling; Wu, Buling

    2013-01-01

    To investigate the ultrastructural changes of dentin irradiated with 980-nm diode laser under different parameters and to observe the morphological alterations of odontoblasts and pulp tissue to determine the safety parameters of 980-nm diode laser in the treatment of dentin hypersensitivity (DH). Twenty extracted human third molars were selected to prepare dentin discs. Each dentin disc was divided into four areas and was irradiated by 980-nm diode laser under different parameters: Group A: control group, 0 J/cm(2); Group B: 2 W/CW (continuous mode), 166 J/cm(2); Group C: 3W/CW, 250 J/cm(2); and Group D: 4W/CW, 333 J/cm(2). Ten additional extracted human third molars were selected to prepare dentin discs. Each dentin disc was divided into two areas and was irradiated by 980-nm diode laser: Group E: control group, 0 J/cm(2); and Group F: 2.0 W/CW, 166 J/cm(2). The morphological alterations of the dentin surfaces and odontoblasts were examined with scanning electron microscopy (SEM), and the morphological alterations of the dental pulp tissue irradiated by laser were observed with an upright microscope. The study demonstrated that dentinal tubules can be entirely blocked after irradiation by 980-nm diode laser, regardless of the parameter setting. Diode laser with settings of 2.0 W and 980-nm sealed exposed dentin tubules effectively, and no significant morphological alterations of the pulp and odontoblasts were observed after irradiation. Irradiation with 980-nm diode laser could be effective for routine clinical treatment of DH, and 2.0W/CW (166 J/cm(2)) was a suitable energy parameter due to its rapid sealing of the exposed dentin tubules and its safety to the odontoblasts and pulp tissue.

  16. In Vitro Study of Dentin Hypersensitivity Treated by 980-nm Diode Laser

    Science.gov (United States)

    Liu, Ying; Gao, Jie; Gao, Yan; XU, Shuaimei; Zhan, Xueling; Wu, Buling

    2013-01-01

    Introduction: To investigate the ultrastructural changes of dentin irradiated with 980-nm diode laser under different parameters and to observe the morphological alterations of odontoblasts and pulp tissue to determine the safety parameters of 980-nm diode laser in the treatment of dentin hypersensitivity (DH). Methods: Twenty extracted human third molars were selected to prepare dentin discs. Each dentin disc was divided into four areas and was irradiated by 980-nm diode laser under different parameters: Group A: control group, 0 J/cm2; Group B: 2 W/CW (continuous mode), 166 J/cm2; Group C: 3W/CW, 250 J/cm2; and Group D: 4W/CW, 333 J/cm2. Ten additional extracted human third molars were selected to prepare dentin discs. Each dentin disc was divided into two areas and was irradiated by 980-nm diode laser: Group E: control group, 0 J/cm2; and Group F: 2.0 W/CW, 166 J/cm2. The morphological alterations of the dentin surfaces and odontoblasts were examined with scanning electron microscopy (SEM), and the morphological alterations of the dental pulp tissue irradiated by laser were observed with an upright microscope. Results: The study demonstrated that dentinal tubules can be entirely blocked after irradiation by 980-nm diode laser, regardless of the parameter setting. Diode laser with settings of 2.0 W and 980-nm sealed exposed dentin tubules effectively, and no significant morphological alterations of the pulp and odontoblasts were observed after irradiation. Conclusions: Irradiation with 980-nm diode laser could be effective for routine clinical treatment of DH, and 2.0W/CW (166 J/cm2) was a suitable energy parameter due to its rapid sealing of the exposed dentin tubules and its safety to the odontoblasts and pulp tissue. PMID:25606318

  17. Characterization of the elastic and viscoelastic properties of dentin by a nanoindentation creep test.

    Science.gov (United States)

    Chuang, Shu-Fen; Lin, Shih-Yun; Wei, Pal-Jen; Han, Chang-Fu; Lin, Jen-Fin; Chang, Hsien-Chang

    2015-07-16

    Dentin is the main supporting structure of teeth, but its mechanical properties may be adversely affected by pathological demineralization. The purposes of this study were to develop a quantitative approach to characterize the viscoelastic properties of dentin after de- and re-mineralization, and to examine the elastic properties using a nanoindentation creep test. Dentin specimens were prepared to receive both micro- and nano-indentation tests at wet and dry states. These tests were repeatedly performed after demineralization (1% citric acid for 3 days) and remineralization (artificial saliva immersion for 28 days). The nanoindentation test was executed in a creep mode, and the resulting displacement-time responses were disintegrated into primary (transient) and secondary (viscous) creep. The structural changes and mineral densities of dentin were also examined under SEM and microCT, respectively. The results showed that demineralization removed superficial minerals of dentin to the depth of 400 μm, and affected its micro- and nano-hardness, especially in the hydrate state. Remineralization only repaired the minerals at the surface layer, and partially recovered the nanohardness. Both the primary the secondary creep increased in the demineralized dentin, while the hydration further enhanced creep deformation of untreated and remineralized dentin. Remineralization reduced the primary creep of dentin, but did not effectively increase the viscosity. In conclusion, water plasticization increases the transient and viscous creep strains of demineralized dentin and reduces load sustainability. The nanoindentation creep test is capable of analyzing the elastic and viscoelastic properties of dentin, and reveals crucial information about creep responses. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Zinc-Containing Restorations Create Amorphous Biogenic Apatite at the Carious Dentin Interface: A X-Ray Diffraction (XRD) Crystal Lattice Analysis.

    Science.gov (United States)

    Toledano, Manuel; Aguilera, Fátima S; López-López, Modesto T; Osorio, Estrella; Toledano-Osorio, Manuel; Osorio, Raquel

    2016-10-01

    The aim of this research was to assess the ability of amalgam restorations to induce amorphous mineral precipitation at the caries-affected dentin substrate. Sound and caries-affected dentin surfaces were subjected to both Zn-free and Zn-containing dental amalgam restorations. Specimens were submitted to thermocycling (100,000 cycles/5°C-55°C, 3 months). Dentin surfaces were studied by atomic force microscopy (nanoroughness), X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive analysis, for physical and morphological surface characterization. Zn-containing amalgam placement reduced crystallinity, crystallite size, and grain size of calcium phosphate crystallites at the dentin surface. Both microstrain and nanoroughness were augmented in caries-affected dentin restored with Zn-containing amalgams. Caries-affected dentin showed the shortest mineral crystallites (11.04 nm), when Zn-containing amalgams were used for restorations, probably leading to a decrease of mechanical properties which might favor crack propagation and deformation. Sound dentin restored with Zn-free amalgams exhibited a substantial increase in length of grain particles (12.44 nm) embedded into dentin crystallites. Zn-containing amalgam placement creates dentin mineralization and the resultant mineral was amorphous in nature. Amorphous calcium phosphate provides a local ion-rich environment, which is considered favorable for in situ generation of prenucleation clusters, promotong further dentin remineralization.

  19. Effect of desensitizing toothpastes on dentin

    Directory of Open Access Journals (Sweden)

    Shelon Cristina Souza Pinto

    2012-10-01

    Full Text Available The objective of this study was to analyze the effects of toothbrushing with desensitizing toothpastes on dentin permeability and dentinal tubule occlusion. Fifty rats provided two hundred incisor teeth divided into five groups: DW, brushed with distilled water (control; FT, brushed with fluoride toothpaste; SCT, brushed with strontium chloride toothpaste; PCT, brushed with potassium citrate toothpaste; and PNT, brushed with potassium nitrate toothpaste. Cavities were prepared to expose the dentinal tubules, and the incisor teeth were brushed using the experimental agents. After each treatment, Evans blue dye solution was applied to the teeth. Dentin permeability was analyzed using scanning electron microscopy and energy-dispersive X-rays (EDX. There were significant differences (p < 0.0001, ANOVA among the groups regarding dentin permeability, number of dentinal tubules, diameter of dentinal tubules, and opened tubular area. In the SCT, PCT and PNT groups, opened and partially occluded tubules, deposits, and a few smear layers were observed. In the DW and FT groups, most of the dentinal tubules were open, with no deposits or smear layers on the dentin. EDX revealed peaks of calcium and phosphorus in all of the groups, as well as traces of strontium in the SCT group and of potassium in the PCT and PNT groups. Desensitizing toothpaste decreased dentin permeability, although it produced only partial dentin tubule occlusion.

  20. Temperature changes across CO2-lased dentin during multiple exposures

    Science.gov (United States)

    Zakariasen, Kenneth L.; Barron, Joseph R.; Boran, Thomas L.

    1990-06-01

    The literature increasingly indicates that lasers will have a multitude of applications for dental hard tissue procedures, e.g. preventive therapy, caries removal, laser etching and endodontic therapy. However, it is critical that such laser therapies avoid the production of heat levels which will be damaging to the surrounding vital tissues, such as the dental pulp and periodontal tissues. Our preliminary research on temperature changes across C02 lased dentin indicated that for single preventive therapeutic exposures (1.2 W., 0. 1 sec., 1.0 mm focal spot) the mean temperature rise across 350 j.tm of dentin was 0.57 0C while across 1000 .tm of dentin the mean rise was only 0.18 °C. Further research utilizing multiple preventive therapeutic exposures (1.2 W., 0. 1 sec., 1.0 mm focal spot, 3 x 1.0 sec. intervals) showed mean temperature elevations of 1.56 0C across 350 m of dentin and 0.66 O across 1000 xm of dentin. While these temperature elevations, which would be associated with preventive therapy, are very low and would be biologically acceptable, it must be noted that exposures of higher intensities are required to fuse enamel and porcelain, or remove decay. This current research investigates temperature elevations which occuT during C02 lasing utilizing the following exposure parameters: 8.0 W., 1.0 mm focal spot, 0.1 sec. exposures, 2 or 4 exposures per site pulsed 1.0 sec. apart. Three dentin thicknesses were utilized, i.e. 1000 jim, 1500 p.tm and 2000 .tm. Four sections of each thickness were utilized with four exposure sites per specimen (2 with 2 exposures, 2 with 4 exposures). All dentin sections were prepared from non-carious third molars using a hard tissue microtome. A thermistor was placed on the dentin surface opposite each lased site and temperature changes were recorded for approximately 50 sec. following lasing. Mean temperature elevations ranged from a high of 3.07 C for the 1000 xm section utilizing four exposures to a low of 0.37 0C for the

  1. Systematic studies of Australian stipoid grasses (Austrostipa based on micro-morphological and molecular characteristics

    Directory of Open Access Journals (Sweden)

    BETTY MAULIYA BUSTAM

    2010-01-01

    Full Text Available Bustam BM (2010 Systematic studies of Australian stipoid grasses (Austrostipa based on micro-morphological and molecular characteristics. Biodiversitas 11: 9-14. This research is one of many studies on stipoid grasses organized by the International Stipeae Working Group (ISWG. This research tested the subgeneric classification of Austrostipa proposed by Jacobs and Everett (1996 and tested how informative the micro morphological characters used. Data were collected from herbarium specimens of 36 species (33 species of Austrostipa, two species of Hesperostipa and one species of Anemanthele at Royal Botanic Gardens, Sydney. Twenty eight micro morphological characters were used. The data were collected from both adaxial and abaxial surfaces of leaves, and from the lemma epidermis using a scanning electron microscope (SEM. ISWG provided the molecular data. Parsimony analysis and a distance method (Unweighteic Pair Group with Arithmatic Mean: UPGMA were used to analyze mico morphological and molecular data separately. Only UPGMA analysis was used to analyze the combined data. The results support the monophyly of Austrostipa. However, there is a little support for the subgeneric classification of Austrostipa proposed by Jacobs and Everett (1996, other than for the consistent recognition of Falcatae. The characters for comparisons between genera are too homoplasious at this level and do not contain enough information for analyses at subgeneric level, a problem apparently shared with the DNA sequences.

  2. Micromorphology and ultrastructure of the floral nectaries of Polemonium caeruleum L. (Polemoniaceae).

    Science.gov (United States)

    Chwil, Mirosława; Chwil, Stanisław

    2012-10-01

    The Polemoniaceae family forms flowers diverse in the terms of pollination methods and nectar types. The micromorphology of the nectary surface and the tissue structures as well as the ultrastructure of the cells of the floral nectaries in Polemonium caeruleum L. were examined using light, scanning and transmission electron microscopy. A bowl-shaped nectary, detached from the ovary, grows at its base. Its contour shows folds with depressions in the places where the stamens grow, forming five-lobed disc (synapomorphic character). Nectar is secreted through modified anomocytic stomata, which are formed in the epidermis covering the tip and the lateral wall of the projection located between the staminal filaments. The undulate nectary consists of a single-layered epidermis and three to nine layers of parenchymal cells. The cells of the nectary contain a dense cytoplasm, numerous plastids with an osmophilic stroma and starch grains, well-developed endoplasmic reticulum, as well as a large number of mitochondria interacting with the Golgi bodies. The ultrastructure of nectary cells indicates the granulocrine secretion mechanism and diversified transport of nectar.

  3. COHESIVE STRENGTH OF DENTIN RESISTÊNCIA COESIVA DA DENTINA

    Directory of Open Access Journals (Sweden)

    Flávio Fernando DEMARCO

    1997-07-01

    Full Text Available The bond strength of dentin adhesives to dentin has increased after each generation. Although dentin substratum is part of the bonding process, little importance has been given to measure dentin cohesive strength. The aim of this study was to evaluate the cohesive strength of dentin in human canines. Seventeen non carious canines were selected. All of them had been extracted for more than one year. The teeth were ground until dentin square samples with approximately 2 X 2 mm were obtained. They were embedded in acrylic resin and subjected to shear stress, in a Wolpert Machine, at a crosshead speed of 0.5 mm/min. The mean cohesive strength of dentin in shear mode was 33.95 (+-9.72 MPa. The fracture surfaces were observed under a X40 magnification. A finite element analysis was performed to observe the stress distribution as related to the shear test. The failure pattern was compatible with the shear test and also with the stress distribution in the finite element analysisA resistência de união dos adesivos dentinários tem sido aumentada com o desenvolvimento de cada nova geração. Pouca importância tem sido dada à resistência coesiva da dentina. A proposta deste estudo foi avaliar a resistência coesiva da dentina. Dezessete caninos humanos hígidos, os quais tinham sido extraídos há mais de um ano, foram usados. Os dentes foram desgastados até a obtenção de corpos-de-prova em dentina, de formato quadrangular, com tamanho aproximado de 2 X 2 mm. Os dentes foram incluídos em resina acrílica e, então, submetidos ao teste de cisalhamento em uma máquina de ensaios universais Wolpert, com uma velocidade de 0,5 mm/min. A resistência coesiva média da dentina no teste de cisalhamento foi de 33,95 (+- 9,72 MPa. O tipo de fratura foi analisado com um aumento de 40X. Foi realizada uma análise com elemento finito, para observar a distribuição do estresse relacionada com o teste de cisalhamento. O padrão de fratura encontrado foi compat

  4. Treatment of dentin with stannous fluoride - SEM and electron microprobe study

    International Nuclear Information System (INIS)

    Ellingsen, J.E.; Roella, G.

    1987-01-01

    The effect of SnF 2 -treatment of dentin surfaces was investigated by means of scanning electron microscopy (SEM) and electron microprobe analysis. Human dentin was treated with aqueous SnF 2 solutions of concentrations varying from 1 to 10%. The treatment periods lasted for 1, 5, 10 or 60 min. Both tin and fluoride were identified on the surfaces. The concentration varied depending on the extensiveness of the treatment. Immersion in 1 M KOH for 15 h removed both tin and fluoride from the surfaces. This reaction was not observed after immersion in H 2 O for the same time period. Examination of the SnF 2 -treated dentin surfaces showed a dense layer of globular particles and in addition some larger particles. The dentinal tubules were totally covered even after the treatment with the lowest concentration of SnF 2 . Deposition of tin- and fluoride-containing globules on dentin surfaces may be of clinical interest. This layer may have importance both for the caries resistance of dentin and for hypersensitivity reactions. (author)

  5. Dentin-cement Interfacial Interaction

    Science.gov (United States)

    Atmeh, A.R.; Chong, E.Z.; Richard, G.; Festy, F.; Watson, T.F.

    2012-01-01

    The interfacial properties of a new calcium-silicate-based coronal restorative material (Biodentine™) and a glass-ionomer cement (GIC) with dentin have been studied by confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), micro-Raman spectroscopy, and two-photon auto-fluorescence and second-harmonic-generation (SHG) imaging. Results indicate the formation of tag-like structures alongside an interfacial layer called the “mineral infiltration zone”, where the alkaline caustic effect of the calcium silicate cement’s hydration products degrades the collagenous component of the interfacial dentin. This degradation leads to the formation of a porous structure which facilitates the permeation of high concentrations of Ca2+, OH-, and CO32- ions, leading to increased mineralization in this region. Comparison of the dentin-restorative interfaces shows that there is a dentin-mineral infiltration with the Biodentine, whereas polyacrylic and tartaric acids and their salts characterize the penetration of the GIC. A new type of interfacial interaction, “the mineral infiltration zone”, is suggested for these calcium-silicate-based cements. PMID:22436906

  6. Micromorphology and histochemical traits of staminal osmophores in Asphodelus aestivus Brot. flower

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The conducted studies pertained to micromorphology of the surface of epidermis cells and histological traits of staminal filaments of Asphodelus aestivus Brot. flowers. The structure of the filaments was analyzed in a light microscope (LM using various histochemical techniques. The morphology of the surface of the epidermis of filaments was observed in scanning electron microscope (SEM. Filaments Asphodelus aestivus accrete together with the basal part of the abaxial surface with the leaves of perianth. Their lower, wider, and flattened part surrounds the ovary. The epidermis of the staminal osmophores creates papilliose cells and unicellular hairs of various sizes. In the uppermost part of these structures, round marks in the cuticle layer after the emission of discharge were observed with the SEM. The outside, convex wall of the isodiametric cells of the epidermis, papillae and hairs was significantly thicker from the remaining walls. It was covered with cuticle of different ornamentation. The cells that created papillae and hairs had a large, centrally located vacuole and a thin layer of cytoplasm with numerous small vacuoles as well as large, often lobed nuclei. In the protoplasts of these cells the presence of plastids and lipid droplets was noted. During the time of secretion of elicitor between the wall and cuticle of the epidermis cells, convex bubbles were formed, in which the secreted substance was accumulated. At the end of secretion, on the surface of papillae, hairs and other cells of the epidermis, irregularly protruding cuticle was observed. It was noted that the composition of staminal osmophores in the flowers of Asphodelus aestivus includes papillae, hairs and cells of the epidermis that do not form papillae.

  7. The effect of endodontic regeneration medicaments on mechanical properties of radicular dentin

    Science.gov (United States)

    Yassen, Ghaeth H.

    Endodontic regeneration treatment of necrotic immature teeth has gained popularity in recent years. The approach suggests a biological alternative to induce a continuous root development. In this project, three in vitro experiments were conducted to investigate the effect of three medicaments used in endodontic regeneration on mechanical properties and chemical structure of radicular dentin. In the first experiment, we investigated longitudinally the effect of medicaments on the indentation properties of the root canal surface of immature teeth using a novel BioDent reference point indenter. A significant difference in the majority of indentation parameters between all groups was found after one-week and one-month application of medicaments (p double antibiotic paste (DAP) > control > calcium hydroxide [Ca(OH)2]. The four-week exposure of dentin to TAP and DAP caused 43% and 31% increase in total indentation distance outcome, respectively. In the second experiment, we investigated longitudinally the effect of medicaments on the chemical structure of immature radicular dentin by measuring the phosphate/amide I ratios of dentin using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy. Phosphate/amide I ratios were significantly different between the four groups after one week, two weeks and four week application of medicaments (p untreated dentin > DAP-treated dentin > TAP-treated dentin. In the third experiment, we investigated longitudinally the effect of medicaments on root fracture resistance and microhardness of radicular dentin. For the microhardness, the two-way interaction between group and time was significant (pmedicaments caused significant decrease in fracture resistance ranging between 19%-30% after three month application compared to one week application. The three medicaments used in endodontic regeneration caused significant change in the chemical integrity of the superficial radicular dentin and significantly affected the indentation

  8. Irradiation of root cervical dentin by using the Nd:YAG laser in vitro study and scanning electron microscopy

    International Nuclear Information System (INIS)

    Britto, Cynthia Tannure Coelho

    2003-01-01

    The dentin hypersensitivity occurs as a result of the dentine exposition to the oral environment, due to loss or removal of enamel or cementum, or both. The hypersensitivity can persist, unless the sealing of the dentin tubules be carried out. Several treatments have been considered, but with less satisfactory and only temporary results. Among these treatments we can cite methods that promote the mechanical occlusion by deposition of substances inside of tubules, by topic application. Nowadays, among the treatments studied, there is the use of lasers, which leads to better clinical efficiency by promoting fusion and re-solidification of the dentin surface, obliterating total or partially the dentin tubules. This in-vitro study was carried out in order to evaluate the efficiency of the Nd:YAG laser in promoting the fusion and re-solidification of the dentin surface, and to evaluate parameters of irradiation typically used, comparing results using photoinitiator with those without it. By observation of the dentin surface, using Scanning Electron Microscopy, it was found extensive areas of fusion and re-solidification, in those groups with photoinitiator, being this technique an efficient resource in the treatment of the dentin hypersensitivity. (author)

  9. Influence of laser etching on enamel and dentin bond strength of Silorane System Adhesive.

    Science.gov (United States)

    Ustunkol, Ildem; Yazici, A Ruya; Gorucu, Jale; Dayangac, Berrin

    2015-02-01

    The aim of this in vitro study was to evaluate the shear bond strength (SBS) of Silorane System Adhesive to enamel and dentin surfaces that had been etched with different procedures. Ninety freshly extracted human third molars were used for the study. After the teeth were embedded with buccal surfaces facing up, they were randomly divided into two groups. In group I, specimens were polished with a 600-grit silicon carbide (SiC) paper to obtain flat exposed enamel. In group II, the overlying enamel layer was removed and exposed dentin surfaces were polished with a 600-grit SiC paper. Then, the teeth in each group were randomly divided into three subgroups according to etching procedures: etched with erbium, chromium:yttrium-scandium-gallium-garnet laser (a), etched with 35% phosphoric acid (b), and non-etched (c, control). Silorane System Adhesive was used to bond silorane restorative to both enamel and dentin. After 24-h storage in distilled water at room temperature, a SBS test was performed using a universal testing machine at a crosshead speed of 1 mm/min. The data were analyzed using two-way ANOVA and Bonferroni tests (p enamel and dentin (p > 0.05). The SBS of self-etch adhesive to dentin was not statistically different from enamel (p > 0.05). Phosphoric acid treatment seems the most promising surface treatment for increasing the enamel and dentin bond strength of Silorane System Adhesive.

  10. Influence of previous acid etching on bond strength of universal adhesives to enamel and dentin.

    Science.gov (United States)

    Torres, Carlos Rocha Gomes; Zanatta, Rayssa Ferreira; Silva, Tatiane Josefa; Huhtala, Maria Filomena Rocha Lima; Borges, Alessandra Bühler

    2017-01-01

    The objective of this study was to evaluate the effect of acid pretreatment on the bond strength of composite resin bonded to enamel and dentin with 2 different universal self-etching adhesives. The null hypothesis was that the acid treatment performed prior to adhesive application would not significantly change the bond strength to enamel or dentin for either universal adhesive tested. A sample of 112 bovine incisors were selected and embedded in acrylic resin. Half were ground until a flat enamel surface was obtained, and the other half were polished until a 6 × 6-mm area of dentin was exposed, resulting into 2 groups (n = 56). The enamel and dentin groups were divided into 2 subgroups according to the adhesive system applied: Futurabond U or Scotchbond Universal. Each of these subgroups was divided into 2 additional subgroups (n = 14); 1 subgroup received phosphoric acid pretreatment, and 1 subgroup did not. The bond strength was assessed with a microtensile test. Data from enamel and dentin specimens were analyzed separately using 1-way analysis of variance. The acid pretreatment did not significantly change the bond strength of the adhesives tested, either to enamel (P = 0.4161) or to dentin (P = 0.4857). The acid etching pretreatment did not affect the bond strength to dentin and enamel when the tested universal multipurpose adhesive systems were used.

  11. Microstructure and wettability of root canal dentine and root canal filling materials after different chemical irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Antonijevic, Djordje; Milovanovic, Petar [Laboratory for Anthropology, Institute for Anatomy, Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Brajkovic, Denis [Department of Dentistry, Faculty of Medical Sciences, University of Kragujevac, Kragujevac (Serbia); Ilic, Dragan [Department of Restorative Medicine, School of Dental Medicine, University of Belgrade, Belgrade (Serbia); Hahn, Michael; Amling, Michael [Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Lottestr. 55A, 22529 Hamburg (Germany); Rakocevic, Zlatko [Laboratory for Atomic Physics, Institute for Nuclear Science “Vinca”, University of Belgrade, Belgrade (Serbia); Djuric, Marija [Laboratory for Anthropology, Institute for Anatomy, Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Busse, Björn, E-mail: b.busse@uke.uni-hamburg.de [Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Lottestr. 55A, 22529 Hamburg (Germany)

    2015-11-15

    Graphical abstract: - Highlights: • Different irrigation solutions and disinfectants were used for treatment of root canal dentine and gutta-percha points. • Materials surface characteristics were assessed using quantitative backscattered electron imaging, reference point indentation, and contact angle analyzer. • The most significant differences in mineralization, indentation, and adhesive outcomes were observed after ethylenediaminetetraacetic acid treatment. • Irrigation solutions confer to superior sealing ability of endodontic filling materials. • Micromechanical characteristics of dentine after irrigation are considerable reduced. - Abstract: The objective of this study was to determine the effects of various irrigation solutions on root canal dentine and gutta-percha surface properties. In addition, the effects of disinfectant chemicals on the wettability and surface morphological properties of the filling materials were evaluated. Ethylenediaminetetraacetic acid (EDTA), citric acid, and ozone were employed as irrigation solutions for dentine and gutta-percha treatment. Thereafter, the samples’ microstructure, degree of mineralization, and mechanical properties were assessed by means of quantitative backscattered electron imaging (qBEI) and reference point indentation (RPI). A contact angle analyzer was used to measure adhesion on the tested materials. Here, EDTA had the most significant affect on both the mechanical properties and the adhesive behavior of dentine. Citric acid did not affect dentine wettability, whereas the indentation properties and the mineralization were reduced. Similar effects were observed when ozone was used. The dentinal tubules were significantly widened in citric acid compared to the ozone group. EDTA causes considerable micromechanical surface alteration of dentine and gutta-percha, but represents the best option in clinical cases where a high adhesiveness of the filling materials is desired.

  12. Dentin bond strength and degree of conversion evaluation of experimental self-etch adhesive systems

    OpenAIRE

    Yazdi, Fatemeh-Maleknejad; Moosavi, Horieh; Atai, Mohammad; Zeynali, Mahsa

    2015-01-01

    Background The aim of this study was to investigate the effect of different concentrations of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) monomer in one-step self-etch experimental adhesives on dentinal microshear bond strength (?SBS), their degree of conversion and bonded micro structure. Material and Methods Composite resin cylinders (Clearfil AP-X) were bonded on human sound molar dentinal surfaces by using five experimental one-step self-etching adhesives (1-SEAs) containing 0% ...

  13. Microstructure and wettability of root canal dentine and root canal filling materials after different chemical irrigation

    International Nuclear Information System (INIS)

    Antonijevic, Djordje; Milovanovic, Petar; Brajkovic, Denis; Ilic, Dragan; Hahn, Michael; Amling, Michael; Rakocevic, Zlatko; Djuric, Marija; Busse, Björn

    2015-01-01

    Graphical abstract: - Highlights: • Different irrigation solutions and disinfectants were used for treatment of root canal dentine and gutta-percha points. • Materials surface characteristics were assessed using quantitative backscattered electron imaging, reference point indentation, and contact angle analyzer. • The most significant differences in mineralization, indentation, and adhesive outcomes were observed after ethylenediaminetetraacetic acid treatment. • Irrigation solutions confer to superior sealing ability of endodontic filling materials. • Micromechanical characteristics of dentine after irrigation are considerable reduced. - Abstract: The objective of this study was to determine the effects of various irrigation solutions on root canal dentine and gutta-percha surface properties. In addition, the effects of disinfectant chemicals on the wettability and surface morphological properties of the filling materials were evaluated. Ethylenediaminetetraacetic acid (EDTA), citric acid, and ozone were employed as irrigation solutions for dentine and gutta-percha treatment. Thereafter, the samples’ microstructure, degree of mineralization, and mechanical properties were assessed by means of quantitative backscattered electron imaging (qBEI) and reference point indentation (RPI). A contact angle analyzer was used to measure adhesion on the tested materials. Here, EDTA had the most significant affect on both the mechanical properties and the adhesive behavior of dentine. Citric acid did not affect dentine wettability, whereas the indentation properties and the mineralization were reduced. Similar effects were observed when ozone was used. The dentinal tubules were significantly widened in citric acid compared to the ozone group. EDTA causes considerable micromechanical surface alteration of dentine and gutta-percha, but represents the best option in clinical cases where a high adhesiveness of the filling materials is desired.

  14. Shear bond strength after dentin bleaching with 10% carbamide peroxide agents

    OpenAIRE

    Basting, Roberta Tarkany; Freitas, Patrícia Moreira de; Pimenta, Luiz André Freire; Serra, Mônica Campos

    2004-01-01

    This in vitro study evaluated the shear bond strength (SBS) of dentin treated with two 10% carbamide peroxide bleaching agents 15 days after bleaching and storage in artificial saliva. Dentin fragments were randomly divided into 3 groups (n = 20) for the treatment with the two different bleaching agents (Rembrandt 10% or Opalescence 10%) or with a placebo agent, applied to the tooth surface for 8 hours a day. During the remaining time, the specimens were stored in artificial saliva. After 42 ...

  15. Anatomical and micromorphological characteristics of the seed coat of field pea (Pisum sativum L. genotypes in relation to cracks and damage of seeds

    Directory of Open Access Journals (Sweden)

    Lazarević Jelena

    2017-01-01

    Full Text Available In this paper, we present the morphological characteristics of the seed and micromorphological, anatomical and chemical characteristics of the seed coat of pea (Pisum sativum L. genotypes, Jezero, Javor and NS Junior. Our aim was to investigate whether these genotypes can be differentiated based on seed coat morphoanatomical characteristics, depending on the harvest treatment. The observations and measurements of seed coat cross-sections were performed using light microscopy. The seed coat surface was observed using SEM. A tuberculate seed coat surface characterized all examined pea genotypes, and the average diameter of the tubercle was about 12 μm. Statistical and laboratory analyses revealed that major damage was the most frequent defect type as the result of mechanized harvest in all the examined genotypes. Genotype NS Junior had the shortest seed length (6.1 mm. Micromorphological analysis revealed that the seed surface was tuberculate in all genotypes. The genotype Jezero had the highest number of tubercle ribs (11.0 and a significantly higher proportion of parenchyma tissue (50.6%, while NS Junior was characterized by the greatest share of macrosclereids (49.8%. The highest number of osteosclereids (832/mm2 was counted in genotype Javor. In addition, genotype NS Junior stands out due to the highest percentage of crude fiber (62.75 g/100g in the seed coat. There was a marked difference among the studied genotypes with regard to the seed coat morphoanatomical characteristics, which is confirmed by the results of multivariate discriminant analysis (MDA. These results suggested that the morphological, micromorphological and anatomical characteristics of the seed might have an impact on the seed coat damage level at harvest. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 31024 and Grant no. 173002

  16. Effects of endodontic post surface treatment, dentin conditioning, and artificial aging on the retention of glass fiber-reinforced composite resin posts.

    Science.gov (United States)

    Albashaireh, Zakereyya S; Ghazal, Muhamad; Kern, Matthias

    2010-01-01

    Several post surface treatments with or without the application of a bonding agent have been recommended to improve the bond strength of resin cements to posts. A regimen that produces the maximum bond strength of glass fiber-reinforced composite resin posts has not been verified. The purpose of this study was to evaluate the influence of post surface conditioning methods and artificial aging on the retention and microleakage of adhesively luted glass fiber-reinforced composite resin posts. Seventy-two endodontically treated single-rooted teeth were prepared for glass fiber-reinforced composite resin posts. The posts were submitted to 3 different surface treatments (n=24), including no treatment, etching with phosphoric acid, and airborne-particle abrasion. Subgroups of the posts (n=8) were then allocated for 3 different experimental conditions: no artificial aging, no bonding agent; no artificial aging, bonding agent; or artificial aging, bonding agent. The posts were luted with resin cement (Calibra). Post retention was measured in tension at a crosshead speed of 2 mm/min. The posts assigned for microleakage investigation were placed in fuchsin dye for 72 hours. The dislodged posts and the post spaces were examined microscopically to evaluate the mode of failure and explore the microleakage. Data were analyzed by 2-way ANOVA followed by Tukey HSD test (alpha=.05). The mean (SD) retention values for test groups ranged from 269 (63.8) to 349 (52.2) N. The retention values of the airborne-particle-abrasion group were significantly higher than those of the acidic-treatment and no-treatment groups. The application of bonding agent on the post surface produced no significant influence on retention. The mean retention values after artificial aging were significantly higher than without artificial aging. Microscopic evaluation demonstrated that the failure mode was primarily mixed. Treating the surface of the posts with phosphoric acid for 15 seconds before cementation

  17. MORPHOLOGICAL AND MICROMORPHOLOGICAL INVESTIGATIONS REGARDING THE LEAVES OF SEVERAL ROSA L. SPECIES

    Directory of Open Access Journals (Sweden)

    Lidia ADUMITRESEI

    2016-12-01

    Full Text Available Multicellular secretory glands are present on Rosa L. species, at least on the stipellae edge; some of them have a larger number and different particularities. The researches have been made on leaves of the following species: Rosa agrestis, R. x damascena, R. multibracteata, R. pimpinellifolia and R. rubiginosa. Micromorphological studies emphasized a large number of cells which forming both terminal secretory part and foot, even though their dimensions are small. These researches highlight the micromorphological aspect of these glands, tector hairs and epicuticular wax. All of them were examined through scanning electron microscopy method.

  18. From micromorphology to palaeoenvironment: The MIS 10 to MIS 5 record in Paudorf (Lower Austria)

    DEFF Research Database (Denmark)

    Sprafke, Tobias; Thiel, Christine; Terhorst, Birgit

    2014-01-01

    The loess-palaeosol sequence (LPS) in Paudorf, Lower Austria is characterised by varying dust sedimentation rates, re-deposition with admixture of local rock fragments, erosion and pedogenic overprinting. Detailed semi-quantitative micromorphological analyses reveal the complex genesis of the pal......The loess-palaeosol sequence (LPS) in Paudorf, Lower Austria is characterised by varying dust sedimentation rates, re-deposition with admixture of local rock fragments, erosion and pedogenic overprinting. Detailed semi-quantitative micromorphological analyses reveal the complex genesis...

  19. Hereditary dentine disorders: dentinogenesis imperfecta and dentine dysplasia

    Directory of Open Access Journals (Sweden)

    MacKie Iain

    2008-11-01

    Full Text Available Abstract The hereditary dentine disorders, dentinogenesis imperfecta (DGI and dentine dysplasia (DD, comprise a group of autosomal dominant genetic conditions characterised by abnormal dentine structure affecting either the primary or both the primary and secondary dentitions. DGI is reported to have an incidence of 1 in 6,000 to 1 in 8,000, whereas that of DD type 1 is 1 in 100,000. Clinically, the teeth are discoloured and show structural defects such as bulbous crowns and small pulp chambers radiographically. The underlying defect of mineralisation often results in shearing of the overlying enamel leaving exposed weakened dentine which is prone to wear. Currently, three sub-types of DGI and two sub-types of DD are recognised but this categorisation may change when other causative mutations are found. DGI type I is inherited with osteogenesis imperfecta and recent genetic studies have shown that mutations in the genes encoding collagen type 1, COL1A1 and COL1A2, underlie this condition. All other forms of DGI and DD, except DD-1, appear to result from mutations in the gene encoding dentine sialophosphoprotein (DSPP, suggesting that these conditions are allelic. Diagnosis is based on family history, pedigree construction and detailed clinical examination, while genetic diagnosis may become useful in the future once sufficient disease-causing mutations have been discovered. Differential diagnoses include hypocalcified forms of amelogenesis imperfecta, congenital erythropoietic porphyria, conditions leading to early tooth loss (Kostmann's disease, cyclic neutropenia, Chediak-Hegashi syndrome, histiocytosis X, Papillon-Lefevre syndrome, permanent teeth discolouration due to tetracyclines, Vitamin D-dependent and vitamin D-resistant rickets. Treatment involves removal of sources of infection or pain, improvement of aesthetics and protection of the posterior teeth from wear. Beginning in infancy, treatment usually continues into adulthood with a

  20. Spine micromorphology of normal and hyperhydric Mammillaria gracilis Pfeiff. (Cactaceae) shoots.

    Science.gov (United States)

    Peharec, P; Posilović, H; Balen, B; Krsnik-Rasol, M

    2010-07-01

    Artificial conditions of tissue culture affect growth and physiology of crassulacean acid metabolism plants which often results in formation of hyperhydric shoots. In in vitro conditions Mammillaria gracilis Pfeiff. (Cactaceae) growth switches from organized to unorganized way, producing a habituated organogenic callus which simultaneously regenerates morphologically normal as well as altered hyperhydric shoots. In this study, influence of tissue culture conditions on morphology of cactus spines of normal and hyperhydric shoots was investigated. Spines of pot-grown Mammillaria plants and of in vitro regenerated shoots were examined with stereo microscope and scanning electron microscope. The pot-grown plants had 16-17 spines per areole. In vitro grown normal shoots, even though they kept typical shoot morphology, had lower number of spines (11-12) and altered spine morphology. This difference was even more pronounced in spine number (six to seven) and morphology of the hyperhydric shoots. Scanning electron microscopy analysis revealed remarkable differences in micromorphology of spine surface between pot-grown and in vitro grown shoots. Spines of in vitro grown normal shoots showed numerous long trichomes, which were more elongated on spines of the hyperhydric shoots; the corresponding structures on spine surface of pot-grown plants were noticed only as small protrusions. Scanning electron microscopy morphometric studies showed that the spines of pot-grown plants were significantly longer compared to the spines of shoots grown in tissue culture. Moreover, transverse section shape varies from elliptical in pot-grown plants to circular in normal and hyperhydric shoots grown in vitro. Cluster and correspondence analyses performed on the scanning electron microscope obtained results suggest great variability among spines of pot-grown plants. Spines of in vitro grown normal and hyperhydric shoots showed low level of morphological variation among themselves despite the

  1. The micromorphology of the blesbuck louse Damalinia (Damalinia crenelata as observed under the scanning electron microscope

    Directory of Open Access Journals (Sweden)

    M.L. Turner

    2003-12-01

    Full Text Available The blesbuck is an important game animal on many game farms and reserves in South Africa. Damalinia crenelata, a biting louse, host-specific to the blesbuck, feed upon epidermal debris of this antelope, leading to severe skin irritation and dermatitis. Symptomatic scratching by the host aggravates these conditions. High infestations may lead to decreased population numbers. Live lice were collected from a blesbuck in the Rietvlei Nature Reserve and prepared for selectron microscopic investigation. Micrographs were recorded. The SEM investigation revealed several micromorphological features not previously described in D. crenelata. Besides the obvious anatomical differences in the reproductive organs of the male and female, several other differences were noted. The antennal flagellae showed morphological differences as well as certain features on the ventral surfaces of the head. Dorsally the forehead was markedly emarginated and showed an acute invagination (clypeo labral suture in the pulvinal area. The ventral surface of the head clearly demonstrated the structures of the preantennal regions such as ventral carina, pulvinus, labrum, mandibles and clypeus. The epipharynx appeared as an underlying extension of the labrum. The rims of the clypeus were more raised and thickened in the female than in that of the male. The mandibles were not notched and were noted to be angular in shape. The three segments of each of the antennae of the male were thicker and more robust than than those of the female. This could suggest sexual dimorphism in this species. The sensilla basoconica comprised 10 pegs. Pit organs were seen within the pore organs. The prothorax and mesothorax were clearly distinguished. The abdominal segments showed six pairs of spiracles. The male andfemale terminalia were confirmed to be strongly sexually dimorphic. The three pairs oflegs each terminated in a single, long and slender, claw.

  2. Separate whitening effects on enamel and dentin after fourteen days.

    Science.gov (United States)

    Kugel, Gerard; Petkevis, Jason; Gurgan, Sevil; Doherty, Eileen

    2007-01-01

    The purpose of this study was to investigate the mechanism of action of a bleaching agent, as it relates to enamel and dentin. Twenty-six extracted human molar teeth were sectioned at the cemento-enamel junction and were randomly assigned to two groups. L*a*b* readings were taken with a spectrophotometer: on buccal surfaces of the crown, at enamel and dentin. The teeth were exposed to carbamide peroxide or placebo gel and L*a*b* scores were again recorded to determine color changes. Treatments were compared using ancova test with baseline color as the covariate. Relative to placebo, buccal surfaces exhibited the greatest Deltab* and DeltaL* color change. On buccal surfaces, the adjusted mean (SE) treatment differences were -7.8 (1.00) for Deltab* and 5.7 (0.97) for DeltaL, with groups differing significantly (p enamel surfaces, treatment differences were -3.6 (0.61) for Deltab* and 4.6 (0.80) for DeltaL* (p tooth crowns exposed to carbamide peroxide 15% was because of the color change in enamel. As compared to enamel, dentin was less affected after 14 days.

  3. Fracture toughness of dentin/resin-composite adhesive interfaces.

    Science.gov (United States)

    Tam, L E; Pilliar, R M

    1993-05-01

    The reliability and validity of tensile and shear bond strength determinations of dentin-bonded interfaces have been questioned. The fracture toughness value (KIC) reflects the ability of a material to resist crack initiation and unstable propagation. When applied to an adhesive interface, it should account for both interfacial bond strength and inherent defects at or near the interface, and should therefore be more appropriate for characterization of interface fracture resistance. This study introduced a fracture toughness test for the assessment of dentin/resin-composite bonded interfaces. The miniature short-rod specimen geometry was used for fracture toughness testing. Each specimen contained a tooth slice, sectioned from a bovine incisor, to form the bonded interface. The fracture toughness of an enamel-bonded interface was assessed in addition to the dentin-bonded interfaces. Tensile bond strength specimens were also prepared from the dentin surfaces of the cut bovine incisors. A minimum of ten specimens was fabricated for each group of materials tested. After the specimens were aged for 24 h in distilled water at 37 degrees C, the specimens were loaded to failure in an Instron universal testing machine. There were significant differences (p adhesives tested. Generally, both the fracture toughness and tensile bond strength measurements were highest for AllBond 2, intermediate for 3M MultiPurpose, and lowest for Scotchbond 2. Scanning electron microscopy of the fractured specimen halves confirmed that crack propagation occurred along the bond interface during the fracture toughness test. It was therefore concluded that the mini-short-rod fracture toughness test provided a valid method for characterization of the fracture resistance of the dentin-resin composite interface.

  4. The use of acetone to enhance the infiltration of HA nanoparticles into a demineralized dentin collagen matrix.

    Science.gov (United States)

    Besinis, Alexandros; van Noort, Richard; Martin, Nicolas

    2016-03-01

    This study investigates the role of acetone, as a carrier for nano-hydroxyapatite (nano-HA) in solution, to enhance the infiltration of fully demineralized dentin with HA nanoparticles (NPs). Dentin specimens were fully demineralized and subsequently infiltrated with two types of water-based nano-HA solutions (one containing acetone and one without). Characterization of the dentin surfaces and nano-HA particles was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The surface wettability and infiltration capacity of the nano-HA solutions were quantified by means of contact angle measurements and energy dispersive X-ray spectroscopy (EDS), respectively. Contact angle measurements were taken at baseline and repeated at regular intervals to assess the effect of acetone. The P and Ca levels of infiltrated dentin specimens were measured and compared to sound dentin and non-infiltrated controls. The presence of acetone resulted in an eight-fold decrease in the contact angles of the nano-HA solutions recorded on the surface of demineralized dentin compared to nano-HA solutions without acetone (one-way ANOVA, pacetone. Infiltration of demineralized dentin with the nano-HA solution containing acetone restored the lost mineral content by 50%, whereas the mean mineralization values for P and Ca in dentin treated with the acetone-free nano-HA solution were less than 6%. Acetone was shown to act as a vehicle to enhance the capacity to infiltrate demineralized dentin with HA NPs. The successful infiltration of dentin collagen with HA NPs provides a suitable scaffold, whereby the infiltrated HA NPs have the potential to act as seeds that may initiate heterogenous mineral growth when exposed to an appropriate mineral-rich environment. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. A study of seed micromorphology in the genus Ophrys (Orchidaceae

    Directory of Open Access Journals (Sweden)

    Galán Cela, Pablo

    2014-12-01

    Full Text Available Seed micromorphology of 19 taxa of the genus Ophrys have been studied using SEM and light microscope. Quantitative data (length and width of seed and embryo, number of testa cells along the longitudinal axis, volume of seed and embryo, and percentage of free air space, as well as qualitative characters (seed shape, features of the anticlinal and periclinal walls, ornamentation and colour were analysed. All the seeds are fusiform, with an asymmetrical basal pole, the periclinal walls of the medial cells have parallel and transverse to slanting ridges, and raised anticlinal walls. Statistical analyses show two large clusters according to the volumes of seed and embryo. Our results support the monophyly of the genus and their recent diversification, however, seed features are not congruent with the recognition of sections and groups within Ophrys.Se ha estudiado la micromorfología de semillas de 19 taxones del género Ophrys mediante el empleo de microscopio óptico y electrónico de barrido. Se han analizado datos cuantitativos (longitud y anchura de la semilla y del embrión, número de células en la testa a lo largo del eje longitudinal, volumen de la semilla y del embrión, y porcentaje de espacio aéreo libre y cualitativos (morfología de la semilla, características de sus paredes anticlinales y periclinales, ornamentación y color. Todas las semillas analizadas son fusiformes, con polo basal asimétrico, ornamentación de las paredes periclinales formada por costillas paralelas y transversales a oblicuas, y paredes anticlinales prominentes. Los análisis estadísticos revelan dos grandes cluster según los valores de los volúmenes de la semilla y el embrión. Nuestros resultados apoyan la monofilia del género y su reciente diversificación, sin embargo, los caracteres micromorfológicos de las semillas no son congruentes con el reconocimiento de secciones y grupos dentro del género Ophrys.

  6. Effect of glutaraldehyde and ferric sulfate on shear bond strength of adhesives to primary dentin

    Directory of Open Access Journals (Sweden)

    Prabhakar A

    2008-12-01

    Full Text Available Aim: The present study was undertaken to evaluate the effect of alternative pulpotomy agents such as glutaraldehyde and ferric sulfate on the shear bond strength of self-etch adhesive systems to dentin of primary teeth. Materials and Methods: Eighty human primary molar teeth were sectioned in a mesiodistal direction and divided into experimental and control groups. Lingual dentin specimens in experimental groups were treated with glutaraldehyde and ferric sulfate. Buccal surfaces soaked in water served as control group. Each group was then divided into two groups based on the adhesive system used: Clearfil SE Bond and Adper Prompt L-Pop. A teflon mold was used to build the composite (Filtek Z-250 cylinders on the dentinal surface of all the specimens. Shear bond strength was tested for all the specimens with an Instron Universal Testing Machine. The failure mode analysis was performed with a Scanning Electron Microscope (SEM. Results: The results revealed that glutaraldehyde and ferric sulfate significantly reduced the shear bond strength of the tested adhesive systems to primary dentin. Clearfil SE Bond showed much higher shear bond strength than Adper Prompt L Pop to primary dentin. SEM analysis revealed a predominant cohesive failure mode for both adhesive systems. Conclusion: This study revealed that the pulpotomy medicaments glutaraldehyde and ferric sulfate adversely affected the bonding of self-etch adhesive systems to primary dentin.

  7. Effect of hydrostatic pressure on regional bond strengths of compomers to dentine.

    Science.gov (United States)

    Zheng, L; Pereira, P N; Somphone, P; Nikaido, T; Tagami, J

    2000-09-01

    The aim of this study was to evaluate the effect of hydrostatic pressure on the regional bond strengths of compomers to dentine. Thirty freshly extracted molars were ground flat to expose the dentine and randomly divided into two groups for bonding: no hydrostatic pressure and hydrostatic pressure of 15cm H(2)O. Xeno CF, Dyract AP and F 2000 were applied to dentine surfaces pretreated by the respective bonding systems following the manufactures' instructions, and then restored with Clearfil AP-X. After 24h storage in water, the teeth were sectioned into 0.7-mm thick slabs and visually divided into three regional subgroups: the region communicating with the pulp through dentinal tubules (pulp horn); the region between the pulp horns (center); and the region between the pulp horn and DEJ (periphery). The specimens were trimmed to a cross-sectional area of 1mm(2) and subjected to the micro-tensile bond test. The data were analyzed by one- and three-way ANOVA, and Fisher's PLSD (p0.05). However, hydrostatic pressure significantly decreased the bond strength of F 2000 to all regions (phydrostatic pressure (p>0.05). For Dyract AP and F 2000, the fracture modes were affected by hydrostatic pressure, while, for Xeno CF, there were no significant differences between the fracture modes with non- or positive hydrostatic pressure. Simulated pulpal pressure of 15cm H(2)O had a greater influence on the bond strengths of compomers to dentine than did dentine regions. Therefore, when measuring the bond strengths of compomers to dentine under the simulated in vivo conditions, the wetness of the dentine surface, as well as the intrinsic properties of each material should be seriously considered.

  8. Grinding efficiency of abutment tooth with both dentin and core composite resin on axial plane.

    Science.gov (United States)

    Miho, Otoaki; Sato, Toru; Matsukubo, Takashi

    2015-01-01

    The purpose of this study was to evaluate grinding efficiency in abutment teeth comprising both dentin and core composite resin in the axial plane. Grinding was performed over 5 runs at two loads (0.5 or 0.25 N) and two feed rates (1 or 2 mm/sec). The grinding surface was observed with a 3-D laser microscope. Tomographic images of the grinding surfaces captured perpendicular to the feed direction were also analyzed. Using a non-ground surface as a reference, areas comprising only dentin, both dentin and core composite resin, or only core composite resin were analyzed to determine the angle of the grinding surface. Composite resins were subjected to the Vickers hardness test and scanning electron microscopy. Data were statistically analyzed using a one-way analysis of variance and multiple comparison tests. Multiple regression analysis was performed for load, feed rate, and Vickers hardness of the build-up material depending on number of runs. When grinding was performed at a constant load and feed rate, a greater grinding angle was observed in areas comprising both dentin and composite resin or only composite resin than in areas consisting of dentin alone. A correlation was found between machinability and load or feed rate in areas comprising both dentin and composite resin or composite resin alone, with a particularly high correlation being observed between machinability and load. These results suggest that great caution should be exercised in a clinical setting when the boundary between the dentin and composite resin is to be ground, as the angle of the grinding surface changes when the rotating diamond point begins grinding the composite resin.

  9. Taxonomic significance of leaf micromorphology in some selected taxa of Acanthaceae (Peninsular Malaysia)

    Science.gov (United States)

    Nurul-Aini, C. A. C.; Noraini, T.; Latiff, A.; Amirul-Aiman, A. J.; Ruzi, A. R.; Idris, S.

    2014-09-01

    Comparative leaf micromorphology study was conducted in eight taxa of Acanthaceae from Peninsular Malaysia. Eight chosen taxa were Acanthus ebracteatus Vahl, A. ilicifolius L., A. volubilis Wall, A. montanus T. Anderson, Andrographis paniculata (Burm.f.) Wall. ex Nees, Asystasia gangetica subsp. micrantha (Nees) Ensermu, Chroesthes longifolia (Wight) B. Hansen and Peristrophe roxburghiana (Schult.) Bremek. The objective of this study was to identify the leaf micromorphological characteristics that can be used in species identification and also as supportive data in classification. The procedures involved such as dehydration, critical point drying, gold coated and examination under scanning electron microscope. Findings in this study have demonstrated the similarities and variations in leaf micromorphological characteristics such as in type of epicuticular waxes, cuticular ornamentations, stomata characteristics and in the presence of trichomes. Six types of epicuticular waxes and five types of trichomes were observed. Variations in cuticular ornamentations and stomata structure can be used to differentiate species. One diagnostic character was found and proven to be very useful to identify Acanthus via the presence of simple trichomes (short-conicle like). In conclusion, the results of this study have shown that leaf micromorphological characteristics have taxonomic significance that can be useful in classifications and identification especially at species level.

  10. Contribution of micromorphology to the taxonomy of Abrus (Leguminosae–Papilionoideae)

    NARCIS (Netherlands)

    Teixeira, G.; Adélia Diniz, M.

    2003-01-01

    Despite the various taxonomic revisions of Abrus Adans., species and infraspecific delimitation are not always clear. In those revisions very little reference is made to micromorphological characters, in particular to those of the compound leaves, in spite of the stability of some of those

  11. Leaf micromorphology of four medicinal ferns species in Tasik Chini, Pahang

    Energy Technology Data Exchange (ETDEWEB)

    Nurnida, M. K., E-mail: nurnidakamal@gmail.com; Noraini, T.; Ruzi, A. R.; Idris, S. [School of Environmental and Natural Resource Sciences Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    A leaf micromorphology study was conducted on four selected medicinal ferns species in Tasik Chini, Pahang. The four chosen species were Adiantum latifolium Lam., Lygodium flexuosum (L.) Sw., Lygodium microphyllum (Cav.) R. Br. and Tectaria singaporeana (Wall.) Ching. The objective of this study is to identify the leaf micromorphological characteristics that can be used as supportive scientific data especially in authentification of medicinal ferns species. The procedures involved such as dehydration, critical point drying, gold coated and examination under scanning electron microscope. Results in this study have shown some similarities and variations in the leaf micromorphological characteristics such as presence of cuticular striation, type of epicuticular waxes, structural feature of stomata and also in the presence or absence and type of trichomes. Four types of epicuticular waxes and only one type of trichome were observed, that were specific for some species. As a conclusion, the results of this study definitely proven that leaf micromorphology can be used for species authentification and might useful as preliminary scientific data for future references and further study.

  12. Micromorphology and systematic distribution of pit membrane thickenings in Oleaceae: Tori and pseudo-tori

    NARCIS (Netherlands)

    Rabaey, D.; Huysmans, S.; Lens, F.; Smets, E.; Jansen, S.

    2008-01-01

    Recent studies on the functional significance of pit membranes in water conducting cells have renewed general interest in their micromorphology. At least two types of pit membrane thickenings have been described in angiosperm families, i.e. genuine tori and pseudo-tori. This study explores the

  13. Ranunculus polyrhizos as a new record for Iran, with ecological and micromorphological evidence

    Directory of Open Access Journals (Sweden)

    Mahmoud Bidarlord

    2016-10-01

    Full Text Available Ranunculus polyrhizos is reported as a new noteworthy record for the flora of Iran. This species was collected from alpine dry gravelly slope in Talesh Mountains. Taxonomic remarks and notes geographical distribution and habitat for this species are provided. Moreover nectar scale, pollen and achene micromorphological characters of the species are added and compared with related species.

  14. Microtensile Bond Strength and Micromorphology of Bur-cut Enamel Using Five Adhesive Systems.

    Science.gov (United States)

    Vinagre, Alexandra; Ramos, João; Messias, Ana; Marques, Fernando; Caramelo, Francisco; Mata, António

    2015-04-01

    This study compared the microtensile bond strengths (μTBS) of two etch-and-rinse (ER) (OptiBond FL [OBFL]; Prime & Bond NT [PBNT]) and three self-etching (SE) (Clearfil SE Bond [CSEB]; Xeno III [XIII]; Xeno V+ [XV+]) adhesives systems to bur-prepared human enamel considering active (AA) and passive (PA) application of the self-etching systems. Ninety-six enamel surfaces were prepared with a medium-grit diamond bur and randomly allocated into 8 groups to receive adhesive restorations: G1: OBFL; G2: PBNT; G3: CSEB/PA; G4: CSEB/ AA; G5: XIII/PA; G6: XIII/AA; G7: XV+/PA; G8: XV+/AA. After composite buildup, samples were sectioned to obtain a total of 279 bonded sticks (1 mm2) that were submitted to microtensile testing (μTBS; 0.5 mm/min) after 24-h water storage (37°C). Etching patterns and adhesive interfacial ultramorphology were also evaluated with confocal laser scanning (CLSM) and scanning electron microscopy (SEM). Data was analyzed with one-way ANOVA (α = 0.05). Weibull probabilistic distribution was also determined. Regarding μTBS, both adhesive system and application mode yielded statistically significant differences (p systems together with CSEB/AA and XIII/PA recorded the highest and statistically similar bond strength results. XV+ presented very low bond strength values, regardless of the application mode. Among self-etching adhesives, CSEB produced significantly higher μTBS values when applied actively. Qualitative evaluation by SEM and CLSM revealed substantial differences between groups both in adhesive interfaces and enamel conditioning patterns. ER and SE adhesive systems presented distinctive bond strengths to bur-cut enamel. The application mode effect was adhesive dependent. Active application improved etching patterns and resin interfaces micromorphology.

  15. Micropropagation, Micromorphological Studies, and In Vitro Flowering in Rungia pectinata L.

    Science.gov (United States)

    Shekhawat, Mahipal S; Manokari, M; Ravindran, C P

    2016-01-01

    A tissue culture protocol was developed for an important medicinal plant Rungia pectinata L. in the present study. Nodal shoots were used as explants and surface-sterilized with 0.1% HgCl2 solution. Murashige and Skoog (MS) medium was used to establish the cultures of R. pectinata. The bud break was reported on MS medium supplemented with 1.0 mg L(-1) 6-benzylaminopurine (BAP). About 98% response was observed with this media combination and maximum 3.2 shoots per explant with 4.3 cm length were recorded. The shoots were further multiplied using MS medium augmented with 0.5 mg L(-1) each of BAP and kinetin (Kin) + 0.1 mg L(-1) indole-3 acetic acid (IAA). Maximum 13.2 shoots per explant with 5.2 cm length were observed. All the shoots were rooted (4.9 roots per shoot with 3.5 cm length) on half strength MS medium fortified with 2.0 mg L(-1) indole-3 butyric acid (IBA). In vitro flowering was induced from the shoots on half strength MS medium supplemented with same concentrations and combinations of growth regulators used for shoot multiplication under 12/12 hr light/dark photoperiod. The plantlets were hardened in the greenhouse for two months and finally transferred to the field. The foliar micromorphological studies revealed the developmental changes in stomata, vein density, and trichomes during the culture of shoots under in vitro conditions.

  16. Micropropagation, Micromorphological Studies, and In Vitro Flowering in Rungia pectinata L.

    Directory of Open Access Journals (Sweden)

    Mahipal S. Shekhawat

    2016-01-01

    Full Text Available A tissue culture protocol was developed for an important medicinal plant Rungia pectinata L. in the present study. Nodal shoots were used as explants and surface-sterilized with 0.1% HgCl2 solution. Murashige and Skoog (MS medium was used to establish the cultures of R. pectinata. The bud break was reported on MS medium supplemented with 1.0 mg L−1 6-benzylaminopurine (BAP. About 98% response was observed with this media combination and maximum 3.2 shoots per explant with 4.3 cm length were recorded. The shoots were further multiplied using MS medium augmented with 0.5 mg L−1 each of BAP and kinetin (Kin + 0.1 mg L−1 indole-3 acetic acid (IAA. Maximum 13.2 shoots per explant with 5.2 cm length were observed. All the shoots were rooted (4.9 roots per shoot with 3.5 cm length on half strength MS medium fortified with 2.0 mg L−1 indole-3 butyric acid (IBA. In vitro flowering was induced from the shoots on half strength MS medium supplemented with same concentrations and combinations of growth regulators used for shoot multiplication under 12/12 hr light/dark photoperiod. The plantlets were hardened in the greenhouse for two months and finally transferred to the field. The foliar micromorphological studies revealed the developmental changes in stomata, vein density, and trichomes during the culture of shoots under in vitro conditions.

  17. Pedogenic calcretes from Coimbatore area, Tamil Nadu: Micromorphology, geochemistry and palaeoclimate significance

    International Nuclear Information System (INIS)

    Hema, A.; Navin, S.

    2004-06-01

    In this paper we present geochemistry and micromorphology (petrography and SEM data) study of Quaternary calcretes formed in association with the vertisol and hardpan calcretes-dolocretes formed on bedrock occurring in Coimbatore area, Tamil Nadu. Coimbatore receives an annual average rainfall of 400-500 mm year -1 . Understanding the formation of calcretes is important as this region falls in the rain shadow region receiving both the south west as well as northeast monsoon. In the study area the calcretes formed within the vertisols representing the Bk horizon occur as thick profiles (∼3m) in the foothill zone while the laminar hardpan calcretes are found in the topographic lows on the bedrock (0.80-1m). Calcretes occurring in association with the vertisols are powdery calcrete, nodular calcrete and rhizoliths with 95.22% to 64.5% of CaCO 3 . Nficromorphology study (thin section and SEM study) of the calcretes in vertisols show the occurrence of features such as alveolar septal structures, calcified filaments, coated grains, spherulites, calcified root cells and calcispheres that indicate the biogenic origin of the calcretes, mainly induced by plant root related microbial activity. They consist of quartzose sand grains cemented by fine crystalline, glaebular, grain-coating and pore-filling micrite. Micro fabrics of hardpan calcretes with detritus hosts show evidence of replacement, displacement and shrinkage, indicating that the calcretes formed under relatively ad conditions. These characteristics reflect that the calcretes formed in a relatively near-surface environment with relatively high rates of evaporation. Development of the calcretes in the vertisol profiles took place in phases of soil formation, erosion and reworking. The relationships between these processes caused the formation of different accrete profiles in the foothill region. (author)

  18. Micromorphology of the floral nectary of red horse chestnut (Aesculus ×carnea Hayne

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2014-04-01

    Full Text Available In Europe Aesculus ×carnea Hayne is planted in cities as an avenue tree. Compared to A. hippocastanum L., it is more drought resistant, but less resistant to low temperatures. A. ×carnea is a lower tree than A. hippocastanum and develops a smaller corolla. It produces dark green, shiny and crinkled leaves. Its flowers have different colours, from bright pink to carmine red. The nectary glands secrete nectar abundantly. Due to the long corolla tube, nectar is difficult to reach for bees. The aim of this study was to investigate the topography and micromorphology of the nectaries of A. ×carnea using scanning electron microscopy. The study shows that the nectary gland of red horse chestnut forms an incomplete ring around the base of the staminal filaments, surrounding only four stamens out of the seven that occur in the flower. Three stamens are outside the nectary. In its widest place, the nectary diameter reaches 2.7 mm. Three expanded portions of the gland can bee seen in the marginal part of the nectary, adjoining the petals. The part of the nectary adjacent to the filaments forms a convex protrusion with a wavy appearance (shape, which results from the vicinity of the filaments. Nectar is secreted through numerous stomata located beneath the convex part of the nectary. The stoma length is 21.7 μm, while the width 23.3 μm. In the material examined, most stomata had open pores. Secretion was observed in many places. The stomata were surrounded by 6-7 guard cells; this allows them to be classified as the cyclocytic type. The cells of the stomatal complex were raised above the surface of the other epidermal cells. The walls of the guard cells and of the adjacent epidermal cells were covered by a cuticle with irregular striation.

  19. Unicystic ameloblastoma with the presence of dentin

    Directory of Open Access Journals (Sweden)

    Sivapathasundharam B

    2007-01-01

    Full Text Available We present a case of unicystic ameloblastoma of the posterior mandible in a 28 year-old female, histologically showing luminal and intramural plexiform epithelial proliferation with typical dentin in the connective tissue capsule. The characteristics of hard tissue formation in ameloblastomas reported in existing literature and the possible origin of the dentin mass seen in our case are discussed.

  20. Raman spectra of human dentin mineral

    NARCIS (Netherlands)

    Tsuda, H; Ruben, J; Arends, J

    Human dentin mineral has been investigated by using micro-Raman spectroscopy. Fluorescence and thermal problems were largely avoided by preparing dentin samples by grinding and ultrasonic agitation in acetone. The Raman spectral features were consistent with those of impure hydroxyapatite containing

  1. Mathematical simulation of the thermal diffusion in dentine irradiated with Nd:YAG laser using finite difference method

    Science.gov (United States)

    Moriyama, Eduardo H.; Zangaro, Renato A.; Lobo, Paulo D. d. C.; Villaverde, Antonio G. J. B.; Watanabe-Sei, Ii; Pacheco, Marcos T. T.; Otsuka, Daniel K.

    2002-06-01

    Thermal damage in dental pulp during Nd:YAG laser irradiation have been studied by several researchers; but due to dentin inhomogeneous structure, laser interaction with dentin in the hypersensitivity treatment are not fully understood. In this work, heat distribution profile on human dentine samples irradiated with Nd:YAG laser was simulated at surface and subjacent layers. Calculations were carried out using the Crank-Nicolson's finite difference method. Sixteen dentin samples with 1,5 mm of thickness were evenly distributed into four groups and irradiated with Nd:YAG laser pulses, according to the following scheme: (I) 1 pulse of 900 mJ, (II) 2 pulses of 450 mJ, (III) 3 pulses of 300 mJ, (IV) 6 pulses of 150 mJ; corresponding to a total laser energy of 900 mJ. The pulse interval was 300ms, the pulse duration of 900 ms and irradiated surface area of 0,005 mm2. Laser induced morphological changes in dentin were observed for all the irradiated samples. The heat distribution throughout the dentin layer, from the external dentin surface to the pulpal chamber wall, was calculated for each case, in order to obtain further information about the pulsed Nd:YAG laser-oral hard tissue interaction. The simulation showed significant differences in the final temperature at the pulpal chamber, depending on the exposition time and the energy contained in the laser pulse.

  2. In vivo effect of a self-etching primer on dentin.

    Science.gov (United States)

    Milia, E; Lallai, M R; García-Godoy, F

    1999-08-01

    To determine the ultrastructural aspects of the dentin collagen area in the cavity preparation floor produced in vivo after phosphoric acid acid-etching or after using Clearfil Liner Bond 2 self-etching primer (LB2 Primer). Twenty-four non-carious third molars scheduled for extraction from young adult patients (16-30 years old) were used. Conventional Class I cavities (+/- 2 mm deep) were prepared on the occlusal surfaces of all teeth using a cylindrical diamond bur on a high-speed handpiece with copious water spray. To avoid dehydration of the dentin, the smear layer-covered dentin was briefly air-dried for 2 seconds. Cavities were assigned at random to the following groups: Group A: Dentin etched for 15 seconds with 34% phosphoric acid, rinsed for 20 seconds and then briefly air-dried for 2 seconds with oil-free compressed air leaving the surfaces slightly moist. Group B: LB2 Primer was applied to the cavity surfaces for 30 seconds and then briefly air-dried to remove the solvent. Group C: The untreated dentin smear layer was used as a control. In all three groups, the cavities were filled incrementally with a resin-based composite (APX), light curing every increment for 40 seconds. After 30 minutes, the teeth were extracted atraumatically and the samples immediately prepared for evaluation with the transmission electron microscope. The use of a self-etching primer did not produce significant morphological changes in the moist dentin substrate. Adverse morphological conditions where observed when there was an excess water on the dentin surface. Phosphoric acid altered the collagen more severely than the self-etching primer.

  3. Ions-modified nanoparticles affect functional remineralization and energy dissipation through the resin-dentin interface.

    Science.gov (United States)

    Toledano, Manuel; Osorio, Raquel; Osorio, Estrella; Medina-Castillo, Antonio Luis; Toledano-Osorio, Manuel; Aguilera, Fátima S

    2017-04-01

    The aim of this study was to evaluate changes in the mechanical and chemical behavior, and bonding ability at dentin interfaces infiltrated with polymeric nanoparticlesstandard deviations and modes of failure are (NPs) prior to resin application. Dentin surfaces were treated with 37% phosphoric acid followed by application of an ethanol suspension of NPs, Zn-NPs or Ca-NPs followed by the application of an adhesive, Single Bond (SB). Bonded interfaces were stored for 24h, submitted to microtensile bond strength test, and evaluated by scanning electron microscopy. After 24h and 21 d of storage, the whole resin-dentin interface adhesive was evaluated using a Nano-DMA. Complex modulus, storage modulus and tan delta (δ) were assessed. AFM imaging and Raman analysis were performed. Bond strength was not affected by NPs infiltration. After 21 d of storage, tan δ generally decreased at Zn-NPs/resin-dentin interface, and augmented when Ca-NPs or non-doped NPs were used. When both Zn-NPs and Ca-NPs were employed, the storage modulus and complex modulus decreased, though both moduli increased at the adhesive and at peritubular dentin after Zn-NPs infiltration. The phosphate and the carbonate peaks, and carbonate substitution, augmented more at interfaces promoted with Ca-NPs than with Zn-NPs after 21 d of storage, but crystallinity did not differ at created interfaces with both ions-doped NPs. Crosslinking of collagen and the secondary structure of collagen improved with Zn-NPs resin-dentin infiltration. Ca-NPs-resin dentin infiltration produced a favorable dissipation of energy with minimal stress concentration trough the crystalline remineralized resin-dentin interface, causing minor damage at this structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Effect of theobromine-containing toothpaste on dentin tubule occlusion in situ.

    Science.gov (United States)

    Amaechi, Bennett T; Mathews, Sapna M; Mensinkai, Poornima K

    2015-01-01

    Dentin hypersensitivity (DH) is treated by either occlusion of dentin tubules or nerve desensitization. This in situ study compared dentin tubules occlusion by theobromine-containing dentifrices with (Theodent-classic-F®, TCF) and without (Theodent-classic®, TC) fluoride with 1,500 ppm fluoride toothpaste, Colgate®-Regular (Fluoride) and Novamin®-containing toothpaste, Sensodyne®-5000-Nupro (Novamin®). Each subject wore four intraoral appliances bearing dentin blocks while using one of four test dentifrices (n = 20/dentifrice) twice daily for 7 days. The four appliances were removed successively after 1, 2, 3, and 7 days. Treated blocks and their control (untreated) blocks were examined with scanning electron microscopy (SEM). Effects were compared statistically (ANOVA/Tukey's) based on percentage of surface area covered by deposited precipitate layer (%DPL) and percentage of fully open (%FOT), partially occluded (%POT), and completely occluded (%COT) tubules in each block calculated relative to the number of tubules in their control blocks. SEM observation indicated an increased %COT and %DPL over time. After 1 and 2 days, %COT was comparable with TC and TCF, and significantly (p Theobromine-containing toothpastes with and without fluoride have equal potential in occluding dentin tubules within a shorter time period than Novamin®-containing toothpaste; however, the three demonstrated equal potential after 1 week, but not the fluoride toothpaste. Theobromine-containing toothpaste promoted dentin tubule occlusion thus shows potential to relief DH.

  5. Risk of initial and moderate caries lesions in primary teeth to progress to dentine cavitation

    DEFF Research Database (Denmark)

    Guedes, Renata S; Piovesan, Chaiana; Floriano, Isabela

    2016-01-01

    AIM: To investigate the risk of sound surfaces, and initial and moderate caries lesions to progress to dentine cavitation in preschool children. DESIGN: A cohort study was designed with 639 children (12-59 months old) who had been examined by visual inspection during a survey in 2010. After 2 years......, 469 children were re-examined regarding the presence of dentine cavitations. The probability of progression was calculated for sound and carious (initial and moderate lesions) surfaces. Relative risk of progression and 95% confidence intervals for each condition compared with sound surfaces were...

  6. Shear bond strength of a new one-bottle dentin adhesive.

    Science.gov (United States)

    Swift, E J; Bayne, S C

    1997-08-01

    To test the shear bond strength of a new adhesive, 3M Single Bond, to dentin surfaces containing different degrees of moisture. Two commercially available one-bottle adhesives (Prime & Bond, One-Step) and a conventional three-step system (Scotchbond Multi-Purpose Plus) were included for comparison. 120 bovine teeth were embedded in acrylic and the labial surfaces were polished to 600 grit to create standardized dentin surfaces for testing. Resin composite was bonded to dentin using a gelatin capsule technique. Four adhesive systems were evaluated with three different degrees of surface moisture (moist, wet, and overwet). Shear bond strengths of adhesives to dentin were determined using a universal testing machine and analyzed by ANOVA and Tukey's post hoc tests. Single Bond had mean shear bond strengths of 19.2, 23.2 and 20.3 MPa to moist, wet, and overwet dentin, respectively. Bond strengths of the three-component system Scotchbond Multi-Purpose Plus ranged from 23.1 to 25.3 MPa, but were not significantly higher than the values for Single Bond. Prime & Bond had bond strengths similar to those of Single Bond, but One-Step had significantly lower bond strengths (P < 0.05) in the wet and overwet conditions.

  7. In vitro dentin permeability after application of Gluma® desensitizer as aqueous solution or aqueous fumed silica dispersion

    Directory of Open Access Journals (Sweden)

    Hiroshi Ishihata

    2011-04-01

    Full Text Available OBJECTIVES: To assess and to compare the effects of Gluma® Desensitizer (GDL with an experimental glutaraldehyde and HEMA containing fumed silica dispersion (GDG on dentin permeability using a chemiluminous tracer penetration test. MATERIAL AND METHODS: Twenty disc-shaped dentin specimens were dissected from extracted human third molars. The dentin specimens were mounted in a split chamber device for determination of permeability under liquid pressure using a photochemical method. Ten specimens were randomly selected and allocated to the evaluation groups Gluma® Desensitizer as aqueous solution and glutaraldehyde/HEMA as fumed silica dispersion, respectively. Dentin disc permeability was determined at two pressure levels after removal of smear with EDTA, after albumin soaking, and after application of the desensitizing agents. Two desensitizer-treated and rinsed specimens of each group were examined by scanning electron microscopy (SEM for surface remnants. RESULTS: Comparatively large standard deviations of the mean EDTA reference and albumin soaked samples permeability values refected the differences of the dentin substrates. The mean chemiluminescence values of specimen treated with GDL and GDG, respectively, were signifcantly reduced after topical application of the desensitizing agents on albumin-soaked dentin. The effects of GDL and GDG on permeability were not signifcantly different. Treated specimens showed no surface remnants after rinsing. CONCLUSIONS: The experimental desensitizer gel formulation reduced dentin permeability as effectively as the original Gluma® Desensitizer solution.

  8. Pulpal progenitors and dentin repair.

    Science.gov (United States)

    Harichane, Y; Hirata, A; Dimitrova-Nakov, S; Granja, I; Goldberg, A; Kellermann, O; Poliard, A

    2011-07-01

    Mesenchymal stem cells are present in the dental pulp. They have been shown to contribute to dentin-like tissue formation in vitro and to participate in bone repair after a mandibular lesion. However, their capacity to contribute efficiently to reparative dentin formation after pulp lesion has never been explored. After pulp exposure, we have identified proliferative cells within 3 zones. In the crown, zone I is near the cavity, and zone II corresponds to the isthmus between the mesial and central pulp. In the root, zone III, near the apex, at a distance from the inflammatory site, contains mitotic stromal cells which may represent a source of progenitor cells. Stem-cell-based strategies are promising treatments for tissue injury in dentistry. Our experiments focused on (1) location of stem cells induced to leave their quiescent state early after pulp injury and (2) implantation of pulp progenitors, a substitute for classic endodontic treatments, paving the way for pulp stem-cell-based therapies.

  9. Infra-red and Raman spectroscopic studies of infected and affected dentine

    International Nuclear Information System (INIS)

    Aminzadeh, A.; Aminzadeh, A.; Khosravy, K.

    2002-01-01

    Diagnosis of infected and affected dentine is an important factor in clinical restorative treatment of dentine. In this study, the IR and Raman spectra of the sound dentine, infected dentine and affected dentine are reported. The structure of infected dentine and affected dentine has been compared with the sound dentine and hydroxyapatite. It is shown while the infected dentine has lost its structure, the affected dentine has more or less a structure similar to the sound dentine. The molecular structure of collagen remains unchanged in both infected and affected dentine

  10. Effects of different peracetic acid formulations on post space radicular dentin.

    Science.gov (United States)

    Belizário, Lauriê Garcia; Kuga, Milton Carlos; Castro-Núñez, Gabriela Mariana; Escalante-Otárola, Wilfredo Gustavo; Só, Marcus Vinicius Reis; Pereira, Jefferson Ricardo

    2018-01-05

    The optimal irrigating solution with antimicrobial and dentin cleansing properties for post space preparation for fiber posts is unclear. Peracetic acid is one option but is available in various chemical formulations that require evaluation. The purpose of this in vitro study was to evaluate dentin surface cleanliness based on the presence of a smear layer and the number of open dentin tubules. It also investigates the chemical composition of residues after canal irrigation with a 1% peracetic acid solution (PA) at low or high concentration of hydrogen peroxide during the preparation of intracanal fiber posts. After filling the root canals of 40 mandibular incisors, a rotary instrument was used for intracanal preparation to place fiber posts. The teeth were divided into 4 groups (n=10) according to the post space irrigation protocol as follows: CG (control): distilled water; NA (NaOCl): 2.5% sodium hypochlorite; LH: PA with low concentration of hydrogen peroxide; and HH: PA with high concentrations of hydrogen peroxide. After irrigation, the teeth were sectioned, and the intracanal dentin surface was subjected to analysis using energy dispersive spectroscopy to evaluate chemical composition and to scanning electron microscopy (×500) to evaluate the presence of the smear layer. The number of open dentin tubules was measured by scanning electron microscopy analysis (×2000) using photo-editing software. ANOVA and the Tukey test (α=.05) were used to evaluate the data, except for the presence of a smear layer, for which the Kruskal-Wallis and Dunn tests were used (α=.05). The highest concentrations of oxygen in the dentin residues were detected in LH and HH (P.05). NA had a higher concentration of chlorine (P.05), except for HH, which also had a larger number of open dentin tubules than CG and NA (P<.05). PA 1% with a low concentration of hydrogen peroxide yielded a lower amount of smear layer and a larger number of open dentin tubules in the dentin of the post

  11. Effect of Dentin Wetness on the Bond Strength of Universal Adhesives

    Science.gov (United States)

    Lee, Ji-Hye; Son, Sung-Ae; Jung, Kyoung-Hwa; Kwon, Yong Hoon

    2017-01-01

    The effects of dentin wetness on the bond strength and adhesive interface morphology of universal adhesives have been investigated using micro-tensile bond strength (μTBS) testing and confocal laser scanning microscopy (CLSM). Seventy-two human third molars were wet ground to expose flat dentin surfaces. They were divided into three groups according to the air-drying time of the dentin surfaces: 0 (without air drying), 5, and 10 s. The dentin surfaces were then treated with three universal adhesives: G-Premio Bond, Single Bond Universal, and All-Bond Universal in self-etch or etch-and-rinse mode. After composite build up, a μTBS test was performed. One additional tooth was prepared for each group by staining the adhesives with 0.01 wt % of Rhodamine B fluorescent dye for CLSM analysis. The data were analyzed statistically using ANOVA and Tukey’s post hoc tests (α = 0.05). Two-way ANOVA showed significant differences among the adhesive systems and dentin moisture conditions. An interaction effect was also observed (p adhesives. PMID:29068404

  12. Adhesive permeability affects coupling of resin cements that utilise self-etching primers to dentine.

    Science.gov (United States)

    Carvalho, R M; Pegoraro, T A; Tay, F R; Pegoraro, L F; Silva, N R F A; Pashley, D H

    2004-01-01

    To examine the effects of an experimental bonding technique that reduces the permeability of the adhesive layer on the coupling of resin cements to dentine. Extracted human third molars had their mid to deep dentin surface exposed flat by transversally sectioning the crowns. Resin composite overlays were constructed and cemented to the surfaces using either Panavia F (Kuraray) or Bistite II DC (Tokuyama) resin cements mediated by their respective one-step or two-step self-etch adhesives. Experimental groups were prepared in the same way, except that the additional layer of a low-viscosity bonding resin (LVBR, Scotchbond Multi-Purpose Plus, 3M ESPE) was placed on the bonded dentine surface before luting the overlays with the respective resin cements. The bonded assemblies were stored for 24 h in water at 37 degrees C and subsequently prepared for microtensile bond strength testing. Beams of approximately 0.8 mm(2) were tested in tension at 0.5 mm/min in a universal tester. Fractured surfaces were examined under scanning electron microscopy (SEM). Additional specimens were prepared and examined with TEM using a silver nitrate-staining technique. Two-way ANOVA showed significant interactions between materials and bonding protocols (p0.05). SEM observation of the fractured surfaces in Panavia F showed rosette-like features that were exclusive for specimens bonded according to manufacturer's directions. Such features corresponded well with the ultrastructure of the interfaces that showed more nanoleakage associated with the more permeable adhesive interface. The application of the additional layer of the LVBR reduced the amount of silver impregnation for both adhesives suggesting that reduced permeability of the adhesives resulted in improved coupling of the resin cements to dentin. Placement of an intermediate layer of a LVBR between the bonded dentine surface and the resin cements resulted in improved coupling of Panavia F to dentine.

  13. Bond strength and microleakage of current dentin adhesives.

    Science.gov (United States)

    Fortin, D; Swift, E J; Denehy, G E; Reinhardt, J W

    1994-07-01

    The purpose of this in vitro study was to evaluate shear bond strengths and microleakage of seven current-generation dentin adhesive systems. Standard box-type Class V cavity preparations were made at the cemento-enamel junction on the buccal surfaces of eighty extracted human molars. These preparations were restored using a microfill composite following application of either All-Bond 2 (Bisco), Clearfil Liner Bond (Kuraray), Gluma 2000 (Miles), Imperva Bond (Shofu), OptiBond (Kerr), Prisma Universal Bond 3 (Caulk), Scotchbond Multi-Purpose (3M), or Scotchbond Dual-Cure (3M) (control). Lingual dentin of these same teeth was exposed and polished to 600-grit. Adhesives were applied and composite was bonded to the dentin using a gelatin capsule technique. Specimens were thermocycled 500 times. Shear bond strengths were determined using a universal testing machine, and microleakage was evaluated using a standard silver nitrate staining technique. Clearfill Liner Bond and OptiBond, adhesive systems that include low-viscosity, low-modulus intermediate resins, had the highest shear bond strengths (13.3 +/- 2.3 MPa and 12.9 +/- 1.5 MPa, respectively). Along with Prisma Universal Bond 3, they also had the least microleakage at dentin margins of Class V restorations. No statistically significant correlation between shear bond strength and microleakage was observed in this study. Adhesive systems that include a low-viscosity intermediate resin produced the high bond strengths and low microleakage. Similarly, two materials with bond strengths in the intermediate range had significantly increased microleakage, and one material with a bond strength in the low end of the spectrum exhibited microleakage that was statistically greater. Thus, despite the lack of statistical correlation, there were observable trends.

  14. Effects of fluoridated milk on root dentin remineralization.

    Directory of Open Access Journals (Sweden)

    Wolfgang H Arnold

    Full Text Available The prevalence of root caries is increasing with greater life expectancy and number of retained teeth. Therefore, new preventive strategies should be developed to reduce the prevalence of root caries. The aim of this study was to investigate the effects of fluoridated milk on the remineralization of root dentin and to compare these effects to those of sodium fluoride (NaF application without milk.Thirty extracted human molars were divided into 6 groups, and the root cementum was removed from each tooth. The dentin surface was demineralized and then incubated with one of the following six solutions: Sodium chloride NaCl, artificial saliva, milk, milk+2.5 ppm fluoride, milk+10 ppm fluoride and artificial saliva+10 ppm fluoride. Serial sections were cut through the lesions and investigated with polarized light microscopy and quantitative morphometry, scanning electron microscopy (SEM and energy-dispersive X-ray spectroscopy (EDS. The data were statistically evaluated using a one-way ANOVA for multiple comparisons.The depth of the lesion decreased with increasing fluoride concentration and was the smallest after incubation with artificial saliva+10 ppm fluoride. SEM analysis revealed a clearly demarcated superficial remineralized zone after incubation with milk+2.5 ppm fluoride, milk+10 ppm fluoride and artificial saliva+10 ppm fluoride. Ca content in this zone increased with increasing fluoride content and was highest after artificial saliva+10 ppm fluoride incubation. In the artificial saliva+10 ppm fluoride group, an additional crystalline layer was present on top of the lesion that contained elevated levels of F and Ca.Incubation of root dentin with fluoridated milk showed a clear effect on root dentin remineralization, and incubation with NaF dissolved in artificial saliva demonstrated a stronger effect.

  15. Influence of dentinal regions on bond strengths of different adhesive systems.

    Science.gov (United States)

    Ozer, F; Unlü, N; Sengun, A

    2003-06-01

    This in vitro study assessed comparatively the shear bond strengths of three composite resins, 3M Valux Plus (3MVP), Herculite (H), Clearfil AP-X (CAP-X), a polyacid modified composite resin Dyract (D), and a resin modified glass-ionomer materials Vitremer (V), to cervical and buccal dentine regions of extracted human molar teeth. Four different bonding systems, 3M ScotchBond Multipurpose (SB), Clearfil Liner Bond 2 (LB2), Opti Bond (OB), and Prime & Bond 2.1 (PB 2.1) were used with the manufacturer's respective composite and compomer materials. One hundred freshly extracted mandibular molar teeth were selected for this study. Flat buccal dentine surfaces were created on 50 teeth and cylindrical rods of the five materials were bonded to the dentine surfaces. For assessment of cervical bond strengths, the materials were bonded to mesial and distal enamel bordered occlusal dentinal surfaces of the remaining 50 teeth. The five groups of restorative procedures were applied as follows; Group 1: SB + 3MVP, Group 2: LB2 + CAP-X, Group 3: OB + H, Group 4: PB2.1 + D, Group 5: Vitremer primer (VP) VP + V. Each restorative procedure thus had 20 specimens (10 buccal + 10 cervical). After 24 h of water storage (37 degrees C), the specimens were tested on a Universal Testing machine in shear with a cross head speed of 0.5 mm min-1. The bond strength values were calculated in MPa and the results were evaluated statistically using Kruskal-Wallis one-way/anova and Mann-Whitney U-tests. It was found that the bond strengths of SB + 3MVP, LB2 + CAP-X and VP + V to buccal dentine surfaces were significantly stronger (P 0.05). Vitremer was found the least successful adhesive material in terms of shear bond strength on both buccal and occluso-cervical dentine surfaces.

  16. Shear bond strength of composite to deep dentin after treatment with two different collagen cross-linking agents at varying time intervals.

    Science.gov (United States)

    Srinivasulu, S; Vidhya, S; Sujatha, M; Mahalaxmi, S

    2012-01-01

    This in vitro study evaluated the shear bond strength of composite resin to deep dentin using a total etch adhesive after treatment with two collagen cross-linking agents at varying time intervals. Thirty freshly extracted human maxillary central incisors were sectioned longitudinally into equal mesial and distal halves (n=60). The proximal deep dentin was exposed, maintaining a remaining dentin thickness (RDT) of approximately 1 mm. The specimens were randomly divided into three groups based on the surface treatment of dentin prior to bonding as follows: group I (n=12, control): no prior dentin surface treatment; group II (n=24): dentin surface pretreated with 10% sodium ascorbate; and group III (n=24): dentin surface pretreated with 6.5% proanthocyanidin. Groups II and III were further subdivided into two subgroups of 12 specimens each, based on the pretreatment time of five minutes (subgroup A) and 10 minutes (subgroup B). Shear bond strength of the specimens was tested with a universal testing machine, and the data were statistically analyzed. Significantly higher shear bond strength to deep dentin was observed in teeth treated with 10% sodium ascorbate (group II) and 6.5% proanthocyanidin (group III) compared to the control group (group I). Among the collagen cross-linkers used, specimens treated with proanthocyanidin showed significantly higher shear bond strength values than those treated with sodium ascorbate. No significant difference was observed between the five-minute and 10-minute pretreatment times in groups II and III. It can be concluded that dentin surface pretreatment with both 10% sodium ascorbate and 6.5% proanthocyanidin resulted in significant improvement in bond strength of resin composite to deep dentin.

  17. Investigationof Clay Mineralogy, Micromorphology and Evolution of Soils in Bajestan Playa

    Directory of Open Access Journals (Sweden)

    Mohammad Ghasemzadeh Ganjehie

    2017-03-01

    Full Text Available Introduction: Playa is one of the most important landscapes in arid regions which covers about 1% of the world's total land area. Study of playas is important from different points of view especially pedology, sedimentology, mineralogy, environmental geology, groundwater and surface water chemistry. More than 60 playas have been identified in Iran. Considering the fact that playas and surrounding landforms are important archive of landscape evolution and paleoenvironmental variations, it seems that less attention has been paid to them so far. Soils are known as indicators of the landscapes evolution. Previous studies in arid regions of Iran imply different periods of deposition and soil formation in playa and alluvial fans or pediments. Bajestan playa is one of the known playa in northeastern Iran, and the largest clay flat exists in this playa. There is no information on the soils and their evolution in Bajestan playa. The objective of this study were to 1 identify the soils in different landforms along a transect from alluvial fan to clay in Bajestan playa 2 determine the morphological, micromorphological and mineralogical characteristics of these soils 3 determine the periods of soil and landform evolution and 4 comparison of soils evolution of the study area to other arid regions of Iran. Material and Methods: The study area of approximately 20000 hectares is located in southeastern of KhorasanRazavi province. The climate of the study area is hot and dry with mean annual temperature and rainfall of 17.3 °C and 193 mm, respectively. Soil moisture regime is aridic with subdivisions of weak aridic and soil temperature regime is thermic. Firstly, landforms and geomorphic surfaces of the study area were recognized based on Google Earth images interpretations and field observations. Four main landforms were recognized in the study area. The landforms from north to the south of the study area were alluvial fan, intermediate alluvial fan- clay flat

  18. Calcretized Ferricretes Around the Jaisalmer Area, Thar Desert, India: Their Chemistry, Mineralogy, Micromorphology and Genesis

    OpenAIRE

    TIWARI, DESIKAN RAMAKRISHNAN & KRISHNA CHANDRA

    2006-01-01

    Ferricrete, an iron duricrust, caps Tertiary and Mesozoic rocks around Jaisalmer in the Indian desert. These ferricretes are associated with two distinct present-day landforms. The upper unit is a high-level dissected, rocky structural plain and the lower one a colluvial flat with soft ferricrete gravels. This study pertains to the first situation wherein field observations, micromorphological features and regolith chemistry suggest an in situ origin for the ferricretes, as in the case of the...

  19. Replica of human dentin treated with different desensitizing agents: a methodological SEM study in vitro

    Directory of Open Access Journals (Sweden)

    Pereira Jose Carlos

    2002-01-01

    Full Text Available This is a preliminary study to determine a methodological sequence in vitro which may allow the reproduction of dentin for SEM analysis, after the use of different desensitizing agents. Dentin discs obtained from extracted human third molars were etched with 6% citric acid, an artificial smear layer was created and the surface dentin discs were divided into four quadrants. Quadrants 2, 3 and 4 of each disc were conditioned with 6% citric acid. The desensitizing agents (Oxa-Gel®, Gluma Desensitizer and an experimental agent were applied to quadrants 3 and 4. To evaluate the acid resistance of the treatment, quadrant 4 was etched again with 6% citric acid. An impression was then taken with Aquasil ULV. After a setting period of 6 min, each disc was removed from the impression and stored in a moist-free environment for 24 h at 37ºC. After that time, a low-viscosity epoxy resin (Araltec GY 1109 BR was poured into the impression and cured for 24 h. All specimens were metal-coated for SEM analysis. Comparison of the photomicrographs of dentin discs with their respective impressions and resin replicas showed that this technique can reproduce the characteristics of the dentin surface treated with desensitizing agents.

  20. Comparison of shear bond strength of amalgam bonded to primary and permanent dentin

    Directory of Open Access Journals (Sweden)

    Mahdi S

    2008-06-01

    Full Text Available Amalgam′s non-adhesive characteristics necessitate cavity preparations incorporating retentive features, which often require the removal of non-carious tooth structure. Use of adhesives beneath amalgam restorations, would be helpful to overcome this disadvantage. This study was undertaken to compare the mean shear bond strength of amalgam bonded to primary and permanent dentin, to evaluate the efficacy of amalgam adhesives in pediatric dentistry.27 primary and 28 permanent posterior teeth with intact buccal or lingual surfaces were grounded to expose dentin and wet-polished with 400-grit silicone carbide paper. Scotchbond Multi Purpose Plus adhesive system was applied to the dentin surfaces and light cured. Amalgam was condensed onto the treated dentin through a plastic mold.shear bond strength testing was done using an Instron Universal testing machine, at a crosshead speed of 0.5 mm/min.The data were analyzed by independent samples t-test The difference among the two groups was not statistically significant (p>0.05 Bonded amalgam showed the same level of bond strength to primary and permanent dentin; so, application of amalgam bonding agents in pediatric dentistry can be recommended.

  1. Machinability of some dentin simulating materials.

    Science.gov (United States)

    Möllersten, L

    1985-01-01

    Machinability in low speed drilling was investigated for pure aluminium, Frasaco teeth, ivory, plexiglass and human dentin. The investigation was performed in order to find a suitable test material for drilling experiments using paralleling instruments. A material simulating human dentin in terms of cuttability at low drilling speeds was sought. Tests were performed using a specially designed apparatus. Holes to a depth of 2 mm were drilled with a twist drill using a constant feeding force. The time required was registered. The machinability of the materials tested was determined by direct comparison of the drilling times. As regards cuttability, first aluminium and then ivory were found to resemble human dentin most closely. By comparing drilling time variances the homogeneity of the materials tested was estimated. Aluminium, Frasaco teeth and plexiglass demonstrated better homogeneity than ivory and human dentin.

  2. Adhesion to pulp chamber dentin: Effect of ethanol-wet bonding technique and proanthocyanidins application

    Directory of Open Access Journals (Sweden)

    Pallavi Sharma

    2015-01-01

    Full Text Available Aim: To evaluate the microleakage of a simplified etch-and-rinse adhesive bonded to pulp chamber dentin with water-wet bonding (WWB or ethanol-wet bonding (EWB with and without proanthocyanidins (PA application. Materials and Methods: Total 88 non-carious extracted human molar teeth were sectioned horizontally to expose the pulp chambers 1.5 mm coronal to the cemento-enamel junction. After the pulp tissue extirpation, canal orifices were enlarged and the root ends were sealed. The samples were randomly divided equally into following four groups according to the four bonding techniques performed using Adper Single Bond 2 [SB] adhesive (1 WWB; (2 EWB; (3 WWB and PA application [WWB + PA]; (4 EWB and PA application [EWB + PA]. Composite resin restorations were performed in all the pulp chambers. Total 20 samples from each group were subjected to microleakage evaluation, and two samples per group were assessed under scanning electron microscope for interfacial micromorphology. Results: The least microleakage score was observed in group 2 (EWB with similar results seen in group 4 (EWB + PA (P = 0.918. Group 2 (EWB showed significantly less microleakage than group 1 (WWB; P = 0.002 and group 3 (WWB + PA; P = 0.009. Group 4 (EWB + PA also depicted significantly reduced microleakage as compared with group 1 (WWB; P = 0.001 and group 3 (WWB + PA; P = 0.003. Conclusion: The use of EWB technique in a clinically relevant simplified dehydration protocol significantly reduced microleakage in simplified etch-and-rinse adhesive, Adper Single Bond 2, bonded to pulp chamber dentin. Application of PA had no significant effect on the microleakage of the adhesive bonded with either WWB or EWB.

  3. Changes in the micromorphology of the corneal subbasal nerve plexus in patients after plaque brachytherapy

    International Nuclear Information System (INIS)

    Zhivov, Andrey; Winter, Karsten; Peschel, Sabine; Stachs, Oliver; Wree, Andreas; Hildebrandt, Guido; Guthoff, Rudolf

    2013-01-01

    To quantify the development of radiation neuropathy in corneal subbasal nerve plexus (SNP) after plaque brachytherapy, and the subsequent regeneration of SNP micromorphology and corneal sensation. Nine eyes of 9 melanoma patients (ciliary body: 3, iris: 2, conjunctiva: 4) underwent brachytherapy (ruthenium-106 plaque, dose to tumour base: 523 ± 231 Gy). SNP micromorphology was assessed by in-vivo confocal microscopy. Using software developed in–house, pre-irradiation findings were compared with those obtained after 3 days, 1, 4 and 7 months, and related to radiation dose and corneal sensation. After 3 days nerve fibres were absent from the applicator zone and central cornea, and corneal sensation was abolished. The earliest regenerating fibres were seen at the one-month follow-up. By 4 months SNP structures had increased to one-third of pre-treatment status (based on nerve fibre density and nerve fibre count), and corneal sensation had returned to approximately two-thirds of pre-irradiation values. Regeneration of SNP and corneal sensation was nearly complete 7 months after plaque brachytherapy. The evaluation of SNP micromorphology and corneal sensation is a reliable and clinically useful method for assessing neuropathy after plaque brachytherapy. Radiation-induced neuropathy of corneal nerves develops quickly and is partly reversible within 7 months. The clinical impact of radiation-induced SNP damage is moderate

  4. Fracture mechanism of coronal teenage dentin

    Science.gov (United States)

    Panfilov, P. E.; Kabanova, A. V.; Borodin, I. N.; Guo, J.; Zang, Z.

    2017-10-01

    The structure of coronal teenage dentin and the development of cracks in it are studied on microand nanolevels. The material is found to fail according to a ductile mechanism on a microlelvel and according to a ductile-brittle mechanism on a nanoscale. This behavior is similar to the failure of a polyethylene film and rubber, when significant elastic and irreversible deformation precedes crack growth. The viscoelastic behavior can be considered as the reaction of dentin to an applied mechanical load.

  5. Efficacy of stannous, fluoride and their their combination in dentin erosion prevention in vitro

    Directory of Open Access Journals (Sweden)

    Amnah Abdullah ALGARNI

    2015-01-01

    Full Text Available The aim of this study was to compare the protective effects of solutions containing stannous (Sn, fluoride (F and their combination in the prevention of dentin erosion. Forty bovine root dentin specimens (4’4’2 mm3 were prepared and randomly assigned to 4 groups (n = 10: SnCl2 (800 ppm/6.7 mM Sn, NaF (250 ppm/13 mM F, NaF/SnCl2 (800 ppm/6.7 mM Sn; 250 ppm/13 mM F, and deionized water (DIW as a negative control. An acquired pellicle was formed on dentin samples by incubation in clarified, pooled, stimulated human saliva for 24 hours. The specimens were subjected to 5 daily cycles, each consisting of 5 of min demineralization (0.3%/15.6 mM citric acid, pH 2.6, 6’/day and 60 min of re-mineralization in clarified human saliva. Thirty minutes after the 1st, 3rd and 5th demineralization episodes of each day, the specimens were treated with one of the test solutions for 2 min. Surface loss was measured via optical profilometry. Mixed-model ANOVA followed by Tukey’s test were used for the statistical analysis. Sn, F, and their combination significantly reduced the dentin surface loss by 23%, 36%, and 60% compared with DIW, respectively. All groups were significantly different (p < 0.05. The combination of Sn and F significantly reduced the amount of dentin surface loss compared with all other groups. The F group also significantly reduced surface loss compared with Sn and DIW, followed by the Sn group, which showed significantly greater protection compared with the DIW control. The daily use of a combined fluoride and stannous solution is promising for preventing dentin erosion.

  6. Smear layer-deproteinizing improves bonding of one-step self-etch adhesives to dentin.

    Science.gov (United States)

    Thanatvarakorn, Ornnicha; Prasansuttiporn, Taweesak; Thittaweerat, Suppason; Foxton, Richard M; Ichinose, Shizuko; Tagami, Junji; Hosaka, Keiichi; Nakajima, Masatoshi

    2018-03-01

    Smear layer deproteinizing was proved to reduce the organic phase of smear layer covered on dentin surface. It was shown to eliminate hybridized smear layer and nanoleakage expression in resin-dentin bonding interface of two-step self-etch adhesive. This study aimed to investigate those effects on various one-step self-etch adhesives. Four different one-step self-etch adhesives were used in this study; SE One (SE), Scotchbond™ Universal (SU), BeautiBond Multi (BB), and Bond Force (BF). Flat human dentin surfaces with standardized smear layer were prepared. Smear layer deproteinizing was carried out by the application of 50ppm hypochlorous acid (HOCl) on dentin surface for 15s followed by Accel ® (p-toluenesulfinic acid salt) for 5s prior to adhesive application. No surface pretreatment was used as control. Microtensile bond strength (μTBS) and nanoleakage under TEM observation were investigated. The data were analyzed by two-way ANOVA and Tukey's post-hoc test and t-test at the significant level of 0.05. Smear layer deproteinizing significantly improved μTBS of SE, SU, and BB (player observed in control groups of SE, BB, and BF, and reticular nanoleakage presented throughout the hybridized complex in control groups of BB and BF were eliminated upon the smear layer deproteinizing. Smear layer deproteinizing by HOCl and Accel ® application could enhance the quality of dentin for bonding to one-step self-etch adhesives, resulting in the improving μTBS, eliminating hybridized smear layer and preventing reticular nanoleakage formation in resin-dentin bonding interface. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  7. In vitro photodynamic antimicrobial chemotherapy in dentine contaminated by cariogenic bacteria

    Science.gov (United States)

    Melo, M. A. S.; de-Paula, D. M.; Lima, J. P. M.; Borges, F. M. C.; Steiner-Oliveira, C.; Nobre-Dos-Santos, M.; Zanin, I. C. J.; Barros, E. B.; Rodrigues, L. K. A.

    2010-06-01

    The development of a method to ensure bacterial-free substrates without extensive cavity preparation would be highly useful to dentistry, since there is no currently available effective method for killing residual bacteria in dentinal tissue. This randomized in vitro study determined parameters for using toluidine blue O (TBO) with a light-emitting diode (LED) for dentine caries disinfection and monitored intrapulpal/periodontal temperatures during irradiation. Occlusal human dentine slabs were immersed in Streptococcus mutans culture for demineralization induction. Slabs were allocated to 10 groups ( n = 15), which were treated with 0.1 mg ml-1 TBO with 5 min of incubation time or 0.9% NaCl solution for 5, 10 or 15 min, and submitted or not to irradiation for 5, 10 or 15 min (47, 94, and 144 J/cm2). Before and after treatments, dentine samples were analyzed with regard to S. mutans counts. In whole teeth, temperature in pulp and periodontium was measured by thermocouples during irradiation. Kruskal-Wallis/Student-Newman-Keuls, and ANOVA/Tukey test were respectively utilized to compare log reductions and temperature rises between groups. Bacterial reduction was observed when dentine was exposed to both TBO and LED at all irradiation times, as well as to LED alone for 10 and 15 min. Temperature increases lower than 2°C were observed for either pulp or periodontium. Concluding, LED combined with TBO is a safe and effective approach for dentine caries disinfection. Nevertheless, additional studies should be conducted to determine the influence of the irradiation in S. mutans viability in dentinal surface/tubules.

  8. Adhesion of multimode adhesives to enamel and dentin after one year of water storage.

    Science.gov (United States)

    Vermelho, Paulo Moreira; Reis, André Figueiredo; Ambrosano, Glaucia Maria Bovi; Giannini, Marcelo

    2017-06-01

    This study aimed to evaluate the ultramorphological characteristics of tooth-resin interfaces and the bond strength (BS) of multimode adhesive systems to enamel and dentin. Multimode adhesives (Scotchbond Universal (SBU) and All-Bond Universal) were tested in both self-etch and etch-and-rinse modes and compared to control groups (Optibond FL and Clearfil SE Bond (CSB)). Adhesives were applied to human molars and composite blocks were incrementally built up. Teeth were sectioned to obtain specimens for microtensile BS and TEM analysis. Specimens were tested after storage for either 24 h or 1 year. SEM analyses were performed to classify the failure pattern of beam specimens after BS testing. Etching increased the enamel BS of multimode adhesives; however, BS decreased after storage for 1 year. No significant differences in dentin BS were noted between multimode and control in either evaluation period. Storage for 1 year only reduced the dentin BS for SBU in self-etch mode. TEM analysis identified hybridization and interaction zones in dentin and enamel for all adhesives. Silver impregnation was detected on dentin-resin interfaces after storage of specimens for 1 year only with the SBU and CSB. Storage for 1 year reduced enamel BS when adhesives are applied on etched surface; however, BS of multimode adhesives did not differ from those of the control group. In dentin, no significant difference was noted between the multimode and control group adhesives, regardless of etching mode. In general, multimode adhesives showed similar behavior when compared to traditional adhesive techniques. Multimode adhesives are one-step self-etching adhesives that can also be used after enamel/dentin phosphoric acid etching, but each product may work better in specific conditions.

  9. Effect of desensitizing agents on dentin permeability.

    Science.gov (United States)

    Ishihata, Hiroshi; Kanehira, Masafumi; Nagai, Tomoko; Finger, Werner J; Shimauchi, Hidetoshi; Komatsu, Masashi

    2009-06-01

    To investigate the in vitro efficacy of two dentin desensitizing products at reducing liquid permeability through human dentin discs. The tested hypothesis was that the products, in spite of different chemical mechanisms were not different at reducing or eliminating flow through dentin discs. Dentin slices (1 mm thick) were prepared from 16 extracted human third molars and their permeability was indirectly recorded in a split chamber model, using a chemiluminescence technique, after EDTA treatment (control), after soaking with albumin, and after desensitizer application. Two products were studied: MS Coat, a self-curing resin-containing oxalate product, and Gluma Desensitizer, a glutaraldehyde/HEMA-based agent without initiator. The dentin slices were mounted between an upper chamber, filled with an aqueous solution of 1% potassium ferricyanide and 0.3% hydrogen peroxide, and a lower chamber filled with 1% sodium hydroxide solution and 0.02% luminol. The upper solution was pressurized, and upon contact with the luminol solution a photochemical signal was generated and recorded as a measure of permeability throughout two consecutive pressurizing cycles at 2.5 and 13 kPa (26 and 133 cm H2O), respectively. The permeability of the control and albumin-soaked samples was similarly high. After application of the desensitizing agents, dentin permeability was reduced to virtually zero at both pressure levels (P < 0.001).

  10. Bonding durability of a self-etching primer system to normal and caries-affected dentin under hydrostatic pulpal pressure in vitro.

    Science.gov (United States)

    Nakajima, Masatoshi; Hosaka, Keiichi; Yamauti, Monica; Foxton, Richard M; Tagami, Junji

    2006-06-01

    To evaluate the bonding durability of a self-etching primer system to normal and caries-affected dentin under hydrostatic pulpal pressure. 18 extracted human molars with occlusal caries were used. Their occlusal dentin surfaces were ground flat to expose normal and caries-affected dentin using #600 SiC paper under running water. Clearfil SE Bond was placed on the dentin surface including the caries-affected dentin according to the manufacturer's instructions and then the crowns were built up with resin composite (Clearfil AP-X) under either a pulpal pressure of 15 cm H2O or none (control). The bonded specimens were stored in 100% humidity for 1 day (control) or for 1 week and 1 month with hydrostatic pulpal pressure. After storage, the specimens were serially sectioned into 0.7 mm-thick slabs and trimmed to an hour-glass shape with a 1 mm2 cross-section, isolated by normal or caries-affected dentin, and then subjected to the micro-tensile bond test. Data were analyzed by two-way ANOVA and Tukey's test (PHydrostatic pulpal pressure significantly reduced the bond strength to normal dentin after 1-month storage (P< 0.05), but did not affect the bond strength to caries-affected dentin.

  11. Bond strength of composite to dentin: effect of acid etching and laser irradiation through an uncured self-etch adhesive system

    International Nuclear Information System (INIS)

    Castro, F L A; Carvalho, J G; Andrade, M F; Saad, J R C; Hebling, J; Lizarelli, R F Z

    2014-01-01

    This study evaluated the effect on micro-tensile bond strength (µ-TBS) of laser irradiation of etched/unetched dentin through an uncured self-etching adhesive. Dentinal surfaces were treated with Clearfil SE Bond Adhesive (CSE) either according to the manufacturer’s instructions (CSE) or without applying the primer (CSE/NP). The dentin was irradiated through the uncured adhesive, using an Nd:YAG laser at 0.75 or 1 W power settings. The adhesive was cured, composite crowns were built up, and the teeth were sectioned into beams (0.49 mm 2 ) to be stressed under tension. Data were analyzed using one-way ANOVA and Tukey statistics (α = 5%). Dentin of the fractured specimens and the interfaces of untested beams were observed under scanning electron microscopy (SEM). The results showed that non-etched irradiated surfaces presented higher µ-TBS than etched and irradiated surfaces (p < 0.05). Laser irradiation alone did not lead to differences in µ-TBS (p > 0.05). SEM showed solidification globules on the surfaces of the specimens. The interfaces were similar on irradiated and non-irradiated surfaces. Laser irradiation of dentin through the uncured adhesive did not lead to higher µ-TBS when compared to the suggested manufacturer’s technique. However, this treatment brought benefits when performed on unetched dentin, since bond strengths were higher when compared to etched dentin. (paper)

  12. An evaluation on microleakage and gap width of different dentin bonding agents in high copper amalgam restorations

    Directory of Open Access Journals (Sweden)

    Ghavam-Nasiri M. Associate Professor

    2003-07-01

    Full Text Available Statement of Problem: A lot of efforts have been made to create a complete adaptation between tooth"nand amalgam restorations."nPurpose: The aim of this study was to evaluate microleakage and interfacial micromorphology of"namalgam restorations lined with dentin adhesives, namely One Coat Bond, Syntac, Excite and Copalite,"nas liners."nMaterials and Methods: 144 intact human canine teeth were selected. Then class V cavities, with"nenamel and dentinal margins, were prepared on each of them. Cavities were lined with different dentin"nbonding systems (Syntac, One Coat Bond and Excite according to the manufacturer's instructions and"nrestored with Oralloy and Cinalloy, non gamma 2 spherical amalgams and Aristaloy a non gamma 2"nAdmixed alloy. Copalite was used in the group, served as controls. After thirty days storage in synthetic"nsaliva at 37°c, the specimens were thermocycled in saliva (4000 cycles. The degree of microleakage was"nassessed by means of basic fushin dye penetration and recorded. The gap width was evaluated with"nScanning Electron Microscope. Pearson and %2 tests were used to analyze the results."nResults: None of the systems, tested in this study, eliminated microleakage completely, Pearson's"ncorrelation coefficient showed a positive correlation between gap and microleakage (P<0/05.Statistical"nsignificant differences were revealed among the liners regarding gap and microleakage (P<0.05."nOne Coat Bond and Syntac appeared to leak less than other groups. The gap width by One Coat Bond"nand Syntac were respectively 0.35 and 0.3 urn in dentine, 0.2 and 0.1 in enamel. Excite and copalite gap"nwidth in dentine and enamel were 1,3-1.36 urn and 0.3-0.6, respectively. The type of amalgam did not"nhave any effect in the degree of microleakage and gap width (P>0/05."nConclusion: One Coat Bond and Syntac, comparing to Excite and Copalite, showed less microleakage"nand gap width.

  13. Effects of matrix metallproteinases on dentin bonding and strategies to increase durability of dentin adhesion

    Directory of Open Access Journals (Sweden)

    Jung-Hyun Lee

    2012-02-01

    Full Text Available The limited durability of resin-dentin bonds severely compromises the longevity of composite resin restorations. Resin-dentin bond degradation might occur via degradation of water-rich and resin sparse collagen matrices by host-derived matrix metalloproteinases (MMPs. This review article provides overview of current knowledge of the role of MMPs in dentin matrix degradation and four experimental strategies for extending the longevity of resin-dentin bonds. They include: (1 the use of broad-spectrum inhibitors of MMPs, (2 the use of cross-linking agents for silencing the activities of MMPs, (3 ethanol wet-bonding with hydrophobic resin, (4 biomimetic remineralization of water-filled collagen matrix. A combination of these strategies will be able to overcome the limitations in resin-dentin adhesion.

  14. Shear bond strength of porcelain laminate veneers to enamel, dentine and enamel-dentine complex bonded with different adhesive luting systems.

    Science.gov (United States)

    Öztürk, Elif; Bolay, Şükran; Hickel, Reinhard; Ilie, Nicoleta

    2013-02-01

    The aim of this study was to evaluate the shear bond strength of porcelain laminate veneers to 3 different surfaces by means of enamel, dentine, and enamel-dentine complex. One hundred thirty-five extracted human maxillary central teeth were used, and the teeth were randomly divided into 9 groups (n=15). The teeth were prepared with 3 different levels for bonding surfaces of enamel (E), dentine (D), and enamel-dentine complex (E-D). Porcelain discs (IPS e.max Press, Ivoclar Vivadent) of 2mm in thickness and 4mm in diameter were luted to the tooth surfaces by using 2 light-curing (RelyX Veneer [RV], 3M ESPE; Variolink Veneer [VV], Ivoclar Vivadent) and a dual-curing (Variolink II [V2], Ivoclar Vivadent) adhesive systems according to the manufacturers' instructions. Shear bond strength test was performed in a universal testing machine at 0.5mm/min until bonding failure. Failure modes were determined under a stereomicroscope, and fracture surfaces were evaluated with a scanning electron microscope. The data were statistically analysed (SPSS 17.0) (p=0.05). Group RV-D exhibited the lowest bond strength value (5.42±6.6MPa). There was statistically no difference among RV-D, V2-D (13.78±8.8MPa) and VV-D (13.84±6.2MPa) groups (p>0.05). Group VV-E exhibited the highest bond strength value (24.76±8.8MPa). The type of tooth structure affected the shear bond strength of the porcelain laminate veneers to the 3 different types of tooth structures (enamel, dentine, and enamel-dentine complex). When dentine exposure is necessary during preparation, enough sound enamel must be protected as much as possible to maintain a good bonding; to obtain maximum bond strength, preparation margins should be on sound enamel. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Wear of dentine in vitro by toothpaste abrasives and detergents alone and combined.

    Science.gov (United States)

    Moore, C; Addy, M

    2005-12-01

    To measure in vitro the abrasion of dentine by toothpaste detergents and abrasives alone and combined. Detergents used were tego betain, sodium lauryl sulphate (SLS), adinol and pluronic diluted to 1% w/v. Abrasives were three artificial silicas, tixosil 73 and 123 and Zeodent 113, and calcium carbonate used at 2.5% w/v. Flat human dentine specimens were brushed with aqueous detergent solutions or abrasive slurries, detergent abrasive slurries and water for 20,000 brush strokes. Dentine loss was measured by non-contacting profilometry at 10,000 and 20,000 strokes. Silica particle size distribution was measured by laser deflection. Loss of dentine occurred with all detergents, abrasives and detergent abrasion combinations, but was not linear with number of brush strokes. Water appeared to remove the smear layer only, but all detergents exceeded the predicted smear layer thickness. The silica abrasives differed in abrasion properties despite similar particle size distribution. Different detergents modulated the abrasives actions in mainly positive or mainly negative directions. Detergents appear able to attack the dentine surface to produce wear. Abrasives vary considerably in wear produced under similar conditions. Detergents modulate the effect of abrasives in a way that may reflect the rheological properties of the mixture.

  16. Enzyme-catalyzed hydrolysis of dentin adhesives containing a new urethane-based trimethacrylate monomer

    Science.gov (United States)

    Park, Jong-Gu; Ye, Qiang; Topp, Elizabeth M.; Spencer, Paulette

    2009-01-01

    A new trimethacrylate monomer with urethane-linked groups, 1,1,1-tri-[4-(methacryloxyethylamino-carbonyloxy)-phenyl]ethane (MPE), was synthesized, characterized, and used as a co-monomer in dentin adhesives. Dentin adhesives containing 2-hydroxyethyl methacrylate (HEMA, 45% w/w) and 2,2-bis[4(2-hydroxy-3-methacryloyloxy-propyloxy)-phenyl] propane (BisGMA, 30% w/w) in addition to MPE (25% w/w) were formulated with H2O at 0 (MPE0), 8 (MPE8) and 16 wt % water (MPE16) to simulate the wet demineralized dentin matrix and compared with controls [HEMA/BisGMA, 45/55 w/w, at 0 (C0), 8 (C8) and 16 wt% water (C16)]. The new adhesive showed a degree of double bond conversion and mechanical properties comparable with control, with good penetration into the dentin surface and a uniform adhesive/dentin interface. On exposure to porcine liver esterase, the net cumulative methacrylic acid (MAA) release from the new adhesives was dramatically (P < 0.05) decreased relative to the control, suggesting that the new monomer improves esterase resistance. PMID:19582843

  17. Effect of ethanol-wet bonding with hydrophobic adhesive on caries-affected dentine.

    Science.gov (United States)

    Huang, Xueqing; Li, Li; Huang, Cui; Du, Xijin

    2011-08-01

    Frequently encountered in clinical practice, caries-affected dentine (CAD) is the most challenging bonding substrate. This study evaluated the effect of ethanol-wet bonding with hydrophobic adhesive to sound dentine and to CAD. In the control groups, prepared sound dentine and CAD were bonded with Adper Single Bond 2 using a traditional water-wet bonding technique. In the experimental groups, the specimens were treated as follows: Group 1, rinsed with stepwise ethanol dehydration; Group 2, immersion in 100% ethanol, three times, for 20 s each time; and Group 3, immersion in 100% ethanol for 20 s. Microtensile bond strength (μTBS) testing was used to evaluate the effects of the different protocols on bonding. The microhardness of debonded dentine surfaces was measured to ensure the presence of CAD. Interfacial nanoleakage was evaluated by field-emission scanning electron microscopy. Treatment significantly improved the μTBS in CAD in Groups 1 and 2, but had no effect on Group 3. Conversely, treatment significantly reduced the μTBS in sound dentine in Groups 2 and 3, but had no effect in Group 1. The presence of nanoleakage varied with the ethanol-wet protocol used. In conclusion, ethanol-wet bonding can potentially improve bond efficacy to CAD when an appropriate protocol is used. © 2011 Eur J Oral Sci.

  18. Micro energy-dispersive x-ray fluorescence spectrometry study of dentin coating with nanobiomaterials

    Science.gov (United States)

    Soares, Luís. Eduardo Silva; Nahorny, Sídnei; Marciano, Fernanda Roberta; Zanin, Hudson; Lobo, Anderson de Oliveira

    2015-06-01

    New biomaterials such as multi-walled carbon nanotubes oxide/graphene oxide (MWCNTO/GO), nanohydroxyapatite (nHAp) and combination of them together or not to acidulated phosphate fluoride gel (F) have been tested as protective coating before root dentin erosion. Fourteen bovine teeth were cleaned, polished, divided into two parts (n=28) and assigned to seven groups: (Control) - without previous surface treatment; F treatment; nHAp; MWCNTO/GO; F+nHAp; F+MWCNTO/GO and F+MWCNTO/GO/nHAp composites. Each sample had two sites of pre-treatments: acid etched area and an area without treatment. After the biomaterials application, the samples were submitted to six cycles (demineralization: orange juice, 10 min; remineralization: artificial saliva, 1 h). Micro energy-dispersive X-ray fluorescence spectrometry (μ-EDXRF) mapping area analyses were performed after erosive cycling on both sites (n=84). μ-EDXRF mappings showed that artificial saliva and MWCNTO/GO/nHAp/F composite treatments produced lower dentin demineralization than in the other groups. Exposed dentin tubules allowed better interaction of nanobiomaterials than in smear layer covered dentin. Association of fluoride with other biomaterials had a positive influence on acid etched dentin. MWCNTO/GO/nHAp/F composite treatment resulted in levels of demineralization similar to the control group.

  19. Long-term bond strength of adhesive systems applied to etched and deproteinized dentin

    Directory of Open Access Journals (Sweden)

    Ninoshka Uceda-Gómez

    2007-12-01

    Full Text Available The aim of this study was to evaluate the early and 12-month bond strength of two adhesive systems (Single Bond-SB and One Step-OS applied to demineralized dentin (WH and demineralized/NaOCl-treated dentin (H. Twenty flat dentin surfaces were exposed, etched, rinsed and slightly dried. For the H groups, a solution of 10% NaOCl was applied for 60 s, rinsed (15 s and slightly dried. The adhesives were applied according to the manufacturer's instructions and composite resin crowns were incrementally constructed. After 24 h (water-37ºC, the specimens was sectioned in order to obtain resin-dentin sticks (0.8 mm². The specimens were tested in microtensile (0.5 mm/min immediately (IM or after 12 months of water storage (12M. The data (MPa were subjected to ANOVA and Tukey's test (a=0.05. Only the main factors adhesive and time were significant (p=0.004 and p=0.003, respectively. SB (42.3±9.1 showed higher bond strengths than OS (33.6±11.6. The mean bond strength for IM-group (42.5±8.7 was statistically superior to 12M (33.3±11.8. The use of 10% NaOCl, after acid etching, did not improve the immediate and the long-term resin-dentin bond strength.

  20. Construction and in vitro test of a new electrode for dentin resistance measurement.

    Science.gov (United States)

    Stein, Steffen; Gente, Michael

    2013-10-01

    It is necessary to reduce the tooth substance before treating a tooth with a dental crown. The preparation often requires reduction of the dentin. This results in a dentin wound and a thinner substance over the pulp, increases the risk of inflammation, and could result in necrosis of the pulp. To give the dentist information about the amount of dentin over the pulp during preparation, the Prepometer was developed. The function of this device is based on the measurement of the electric resistance of the tooth substance. The measuring behavior of the first-generation Prepometer is characterized by smaller values of electric resistance before reaching full contact of the measuring head to the dentin surface and the actual value RT. This measuring behavior can mislead inexperienced therapists with inaccurate values that suggest thinner dentin than the reality. In this study, a new electrode based on the technology of active guard drive was constructed to overcome this issue. The results show that improvement in the measuring behavior of the new electrode could be achieved, eliminating the earlier disadvantage of the Prepometer.

  1. In vitro propagation, ex vitro rooting and leaf micromorphology of Bauhinia racemosa Lam.: a leguminous tree with medicinal values.

    Science.gov (United States)

    Sharma, Udit; Kataria, Vinod; Shekhawat, N S

    2017-10-01

    A micropropagation system for Bauhinia racemosa Lam. was developed involving axillary shoot proliferation and ex vitro rooting using nodal explants obtained from mature tree. MS medium with 3.0 mg l -1 BA (6-benzyladenine) was optimum for shoot bud induction. For shoot multiplication, mother explants were transferred repeatedly on medium containing low concentration of BA (0.75 mg l -1 ). Number of shoots was increased up to two passages and decreased thereafter. Shoot multiplication was further enhanced on MS medium containing 0.25 mg l -1 each of BA and Kin (Kinetin) with 0.1 mg l -1 of NAA (α-naphthalene acetic acid). Addition of 0.004 mg l -1 TDZ (thidiazuron) increased the rate of shoot multiplication and 21.81 ± 1.26 shoots per culture vessel were obtained. In vitro regenerated shoots were rooted under ex vitro conditions treated with 400 mg l -1 IBA (indole-3-butyric acid) for 7 min on sterile soilrite. After successful hardening in greenhouse, ex vitro rooted plants were transferred to the field conditions with ≈85% of survival rate. Micromorphological changes were observed on leaf surface i.e. development of vein density and trichomes and stomatal appearance, when plants were subjected to environmental conditions. This is the first report on in vitro regeneration of B. racemosa from mature tree.

  2. Extrafibrillar collagen demineralization-based chelate-and-rinse technique bridges the gap between wet and dry dentin bonding.

    Science.gov (United States)

    Mai, Sui; Wei, Chin-Chuan; Gu, Li-Sha; Tian, Fu-Cong; Arola, Dwayne D; Chen, Ji-Hua; Jiao, Yang; Pashley, David H; Niu, Li-Na; Tay, Franklin R

    2017-07-15

    Limitations associated with wet-bonding led to the recent development of a selective demineralization strategy in which dentin was etched with a reduced concentration of phosphoric acid to create exclusive extrafibrillar demineralization of the collagen matrix. However, the use of acidic conditioners removes calcium via diffusion of very small hydronium ions into the intrafibrillar collagen water compartments. This defeats the purpose of limiting the conditioner to the extrafibrillar space to create a collagen matrix containing only intrafibrillar minerals to prevent collapse of the collagen matrix. The present work examined the use of polymeric chelators (the sodium salt of polyacrylic acid) of different molecular weights to selectively demineralize extrafibrillar dentin. These polymeric chelators exhibit different affinities for calcium ions (isothermal titration calorimetry), penetrated intrafibrillar dentin collagen to different extents based on their molecular sizes (modified size-exclusion chromatography), and preserve the dynamic mechanical properties of mineralized dentin more favorably compared with completely demineralized phosphoric acid-etched dentin (nanoscopical dynamic mechanical analysis). Scanning and transmission electron microscopy provided evidence for retention of intrafibrillar minerals in dentin surfaces conditioned with polymeric chelators. Microtensile bond strengths to wet-bonded and dry-bonded dentin conditioned with these polymeric chelators showed that the use of sodium salts of polyacrylic acid for chelating dentin prior to bonding did not result in significant decline in resin-dentin bond strength. Taken together, the findings led to the conclusion that a chelate-and-rinse conditioning technique based on extrafibrillar collagen demineralization bridges the gap between wet and dry dentin bonding. The chelate-and-rinse dental adhesive bonding concept differentiates from previous research in that it is based on the size

  3. Degradation of Multimode Adhesive System Bond Strength to Artificial Caries-Affected Dentin Due to Water Storage.

    Science.gov (United States)

    Follak, A C; Miotti, L L; Lenzi, T L; Rocha, R O; Soares, F Z

    The purpose of this study was to evaluate the influence of water storage on bond strength of multimode adhesive systems to artificially induced caries-affected dentin. One hundred twelve sound bovine incisors were randomly assigned to 16 groups (n=7) according to the dentin condition (sound; SND, artificially induced caries-affected dentin; CAD, cariogenic challenge by pH cycling for 14 days); the adhesive system (SU, Scotchbond Universal Adhesive; AB, All-Bond Universal; PB, Prime & Bond Elect; SB, Adper Single Bond 2; and CS, Clearfil SE Bond), and the etching strategy (etch-and-rinse and self-etch). All adhesive systems were applied under manufacturer's instructions to flat dentin surfaces, and a composite block was built up on each dentin surface. After 24 hours of water storage, the specimens were sectioned into stick-shaped specimens (0.8 mm 2 ) and submitted to a microtensile test immediately (24 hours) or after six months of water storage. Bond strength data (MPa) were analyzed using three-way repeated-measures analysis of variance and post hoc Tukey test (α=5%), considering each substrate separately (SND and CAD). The etching strategy did not influence the bond strength of multimode adhesives, irrespective of the dentin condition. Water storage only reduced significantly the bond strength to CAD. The degradation of bond strength due to water storage was more pronounced in CAD, regardless of the etching strategy.

  4. Effect of a retention groove on the shear bond strength of dentin-bonded restorations

    NARCIS (Netherlands)

    de Kok, P.; de Jager, N.; Veerman, I.A.M.; Hafeez, N.; Kleverlaan, C.J.; Roeters, J.F.M.

    2016-01-01

    Statement of problem. With the increasing use of minimally invasive restorations, effective adhesion becomes more important. Applying mechanical retention to a flat dentin surface might improve the adhesion of ceramic and composite resin restorations. Purpose. The purpose of this in vitro study was

  5. The micromorphological features of Gladiolus imbricatus L. (Iridaceae Juss.

    Directory of Open Access Journals (Sweden)

    Sviltlana L. Zhygalova

    2013-04-01

    Full Text Available The aim of this study is to give a complete description of the surface structure of the leaves, seeds and pollen grains ofGladiolus imbricatusfrom the flora of Ukraine, and to investigate whether these characters are useful systematically.

  6. Evaluation of matrix metalloproteinase and cysteine cathepsin activity in dentin hybrid layer by gelatin zymography.

    Science.gov (United States)

    Mahalaxmi, Sekar; Madhubala, Manavalan Madhana; Jayaraman, Mahendran; Sathyakumar, Shanmugasundaram

    2016-01-01

    The aim of this study was to comparatively assess the gelatinolytic activity of matrix metalloproteinases(MMPs) and Cysteine Cathepsins (CCs) in the adhesive interface using etch and rinse adhesive at different time intervals using zymographic technique. Twenty freshly extracted non-carious human third molars were used in this study. Occlusal surfaces were ground flat and 1mm thick horizontal dentin slabs were obtained from each tooth using a diamond disc. The dentin surface was polished with 600-grit silicon-carbide paper. Five out of 20 samples were directly pulverized. In the remaining fifteen samples, the dentin was etched and adhesive was applied and light cured according to the manufacturer's instructions. A 1mm thick flowable composite was build up and light cured. Bonded specimens were cut vertically into 3 to 4 dentin slabs by means of diamond disc to expose the adhesive/dentin interfaces. These were then ground down to 500 µm thick resin-dentin interface using a hard tissue microtome. These sections were then pulverised into powder. Following this, every five samples were subjected to zymographic analysis after 1 day, 7 days and 21 days. Zymograms showed clear, thicker bands on all three isoforms in the etched samples compared to control samples at 1st and 7th day intervals and became inactive at 21st day for all three isoforms. MMP 9 activity was relatively higher when compared to CCs and MMP 2. Etch and rinse adhesive activated MMPs and CCs within the hybrid layer that remained active till 7th day and no gelatinolytic activity was found on 21st day and MMPs are more active compared to CCs and MMP-2.

  7. Improved degree of conversion of model self-etching adhesives through their interaction with dentin

    Science.gov (United States)

    Zhang, Ying; Wang, Yong

    2011-01-01

    Objective To investigate the correlation of the chemical interaction between model self-etching adhesives and dentin with the degree of conversion (DC) of the adhesives. Methods The model self-etching adhesives contained bis[2-methacryloyloxy)ethyl] phosphate (2MP) and 2-hydroxyethyl methacrylate (HEMA) with a mass ratio of 1/1, and 0-40% water contents, respectively. The adhesives were applied either onto the prepared dentin surface or unreactive substrates (such as glass slides), agitated for 15s, then light-cured for 40s. The DCs of the adhesives were determined using micro-Raman spectral and mapping analysis. Results The DCs of the adhesives cured on the dentin substrate were found to be significantly higher than those on the unreactive glass substrate. Moreover, the DCs of the adhesives displayed a decreasing trend as the distance from the dentin surface became greater. The chemical interaction of the acidic 2MP/HEMA adhesives with the mineral apatite in dentin was proposed to play a significant role for the observations. The chemical interaction could be validated by the spectral comparison in the phosphate regions of 1100 cm−1 and 960 cm−1 in the Raman spectra. The results also revealed a notable influence of water content on the DC of adhesives. The DCs of the adhesive at 10% water content exhibited the highest DC level for both substrates. Conclusions Interaction with dentin dramatically improved the degree of conversion of self-etching adhesives. Our ability to chemically characterize the a/d interface including in situ detection of the DC distribution is very important in understanding self-etching adhesive bonding under in vivo conditions. PMID:22024375

  8. Improved degree of conversion of model self-etching adhesives through their interaction with dentine.

    Science.gov (United States)

    Zhang, Ying; Wang, Yong

    2012-01-01

    To investigate the correlation of the chemical interaction between model self-etching adhesives and dentine with the degree of conversion (DC) of the adhesives. The model self-etching adhesives contained bis[2-methacryloyloxy)ethyl] phosphate (2MP) and 2-hydroxyethyl methacrylate (HEMA) with a mass ratio of 1/1, and 0-40% water contents, respectively. The adhesives were applied either onto the prepared dentine surface or unreactive substrates (such as glass slides), agitated for 15s, then light-cured for 40s. The DCs of the adhesives were determined using micro-Raman spectral and mapping analysis. The DCs of the adhesives cured on the dentine substrate were found to be significantly higher than those on the unreactive glass substrate. Moreover, the DCs of the adhesives displayed a decreasing trend as the distance from the dentine surface became greater. The chemical interaction of the acidic 2MP/HEMA adhesives with the mineral apatite in dentine was proposed to play a significant role for the observations. The chemical interaction could be validated by the spectral comparison in the phosphate regions of 1100 cm(-1) and 960 cm(-1) in the Raman spectra. The results also revealed a notable influence of water content on the DC of adhesives. The DCs of the adhesive at 10% water content exhibited the highest DC level for both substrates. Interaction with dentine dramatically improved the degree of conversion of self-etching adhesives. Our ability to chemically characterise the a/d interface including in situ detection of the DC distribution is very important in understanding self-etching adhesive bonding under in vivo conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Optimization of the etch-and-rinse technique: New perspectives to improve resin-dentin bonding and hybrid layer integrity by reducing residual water using dimethyl sulfoxide pretreatments.

    Science.gov (United States)

    Stape, Thiago Henrique Scarabello; Tjäderhane, Leo; Abuna, Gabriel; Sinhoreti, Mário Alexandre Coelho; Martins, Luís Roberto Marcondes; Tezvergil-Mutluay, Arzu

    2018-04-13

    To determine whether bonding effectiveness and hybrid layer integrity on acid-etched dehydrated dentin would be comparable to the conventional wet-bonding technique through new dentin biomodification approaches using dimethyl sulfoxide (DMSO). Etched dentin surfaces from extracted sound molars were randomly bonded in wet or dry conditions (30s air drying) with DMSO/ethanol or DMSO/H 2 O as pretreatments using a simplified (Scotchbond Universal Adhesive, 3M ESPE: SU) and a multi-step (Adper Scotchbond Multi-Purpose, 3M ESPE: SBMP) etch-and-rinse adhesives. Untreated dentin surfaces served as control. Bonded teeth (n=8) were stored in distilled water for 24h and sectioned into resin-dentin beams (0.8mm 2 ) for microtensile bond strength test and quantitative interfacial nanoleakage analysis (n=8) under SEM. Additional teeth (n=2) were prepared for micropermeability assessment by CFLSM under simulated pulpar pressure (20cm H 2 O) using 5mM fluorescein as a tracer. Microtensile data was analyzed by 3-way ANOVA followed by Tukey Test and nanoleakage by Kruskal-Wallis and Dunn-Bonferroni multiple comparison test (α=0.05). While dry-bonding of SBMP produced significantly lower bond strengths than wet-bonding (padhesives to demineralized air-dried dentin beyond conventional wet-bonding. Less porous resin-dentin interfaces with higher bond strengths on air-dried etched dentin were achieved; nonetheless, overall efficiency varied according to DMSO's co-solvent and adhesive type. DMSO pretreatments permit etched dentin to be air-dried before hybridization facilitating residual water removal and thus improving bonding effectiveness. This challenges the current paradigm of wet-bonding requirement for the etch-and-rinse approach creating new possibilities to enhance the clinical longevity of resin-dentin interfaces. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

  10. [Mantle dentin as biomodel of materials for structural teeth restoration].

    Science.gov (United States)

    Starodubova, A V; Vinnichenko, Yu A; Pourovskaya, I Ya; Rusanov, F S

    The article describes a structural element of natural teeth - mantle dentin. It has been shown that the presence of this element in the structure of a natural tooth largely ensures its strength under the influence of repeated loads in a functional oral environment and arrests crack growth at the enamel/dentine interface. This later effect is explained by the influence of a thin layer of mantle dentine, which has physical and mechanical characteristics different from that of the main dentin.

  11. Microtensile bond strength and scanning electron microscopic evaluation of zirconia bonded to dentin using two self-adhesive resin cements; effect of airborne abrasion and aging

    Directory of Open Access Journals (Sweden)

    Reem Gamal

    2017-12-01

    Conclusions: Airborne abrasion-surface treatment of zirconia significantly enhanced the μTBS of both cements adhered to dentin while aging had an adverse effect. MS showed higher insignificant μTBS.

  12. [Micromorphology of pejibaye leaflets Bactris gasipaes (Arecaceae) var. diamonds-10].

    Science.gov (United States)

    Sánchez-Chacón, Ethel; Alvarado-Rodríguez, Olman; Rodríguez-Arrieta, Alexander; Gómez-Alpízar, Luis

    2016-09-01

    Bactris gasipaes is widely cultivated for the consumption of palm hearts and fruits. The present work describes the micro morphological characteristics of leaflets from adult plants of B. gasipaes, thornless variety Diamantes-10, collected in the Diamantes Experimental Station in Guápiles, Costa Rica. We collected 25 leaflets and analyses were performed with a combination of microscopy techniques: light microscopy, scanning electron microscopy and transmission electron microscopy to study their structure. Our results showed that leaflets have abundant epicuticular wax on adaxial and abaxial surfaces. Analyses from the epidermis indicated that it is composed of isodiametric cells, and it is also evident that hypodermis cells have rectangular shape and are larger than the other epidermal cells. We observed stomata on both surfaces, but they were more abundant in the abaxial surface. On the other hand, the epidermis showed the presence of trichomes with three different morphologies. In the parenchyma, cells are large and not well defined, and we observed the presence of astroesclereids, and compact groups of fiber bundles between parenchyma cells. The central vein has several vascular bundles, arranged in a continuous manner, and they are surrounded by sclerotic tissue; some of these fibers presented live protoplasts. All minor veins showed the same anatomy as the central vein. In these veins, the vessel elements of protoxylem and metaxylem showed scalariform ornaments on their walls. Phloem is located towards the adaxial surface of the vein and we observed sieve and companion cells surrounded by fibers and parenchyma cells. The companion cells presented branched plasmodesmata attached to a sieve element, and in these elements we found protein bodies called P-protein. The main anatomical difference in the leaflets of the var. Diamantes-10, compared to the other varieties of B. gasipaes K, is the lack of thorns; the other morphological features seem to be conserved.

  13. Effect of adhesive resin cements on bond strength of ceramic core materials to dentin.

    Science.gov (United States)

    Gundogdu, M; Aladag, L I

    2018-03-01

    The aim of the present study was to evaluate the effects of self-etch and self-adhesive resin cements on the shear bond strength of ceramic core materials bonded to dentin. Extracted, caries-free, human central maxillary incisor teeth were selected, and the vestibule surfaces were cut flat to obtain dentin surfaces. Ceramic core materials (IPS e.max Press and Prettau Zirconia) were luted to the dentin surfaces using three self-etch adhesive systems (Duo-Link, Panavia F 2.0, and RelyX Ultimate Clicker) and two self-adhesive resin systems (RelyX U200 Automix and Maxcem Elite). A shear bond strength test was performed using a universal testing machine. Failure modes were observed under a stereomicroscope, and bonding interfaces between the adhesive resin cements and the teeth were evaluated with a scanning electron microscope. Data were analyzed with Student's t-test and one-way analysis of variance followed by Tukey's test (α = 0.05). The type of adhesive resin cement significantly affected the shear bond strengths of ceramic core materials bonded to dentin (P materials when the specimens were luted with self-adhesive resin cements (P materials.

  14. Enamel and dentin bond strengths of a new self-etch adhesive system.

    Science.gov (United States)

    Walter, Ricardo; Swift, Edward J; Boushell, Lee W; Braswell, Krista

    2011-12-01

    statement of problem:  Self-etch adhesives typically are mildly acidic and therefore less effective than etch-and-rinse adhesives for bonding to enamel.   The purpose of this study was to evaluate the enamel and dentin shear bond strengths of a new two-step self-etch adhesive system, OptiBond XTR (Kerr Corporation, Orange, CA, USA).   The labial surfaces of 80 bovine teeth were ground to create flat, 600-grit enamel or dentin surfaces. Composite was bonded to enamel or dentin using the new two-step self-etch system or a three-step etch-and-rinse (OptiBond FL, Kerr), two-step self-etch (Clearfil SE Bond, Kuraray America, Houston, TX, USA), or one-step self-etch adhesive (Xeno IV, Dentsply Caulk, Milford, DE, USA). Following storage in water for 24 hours, shear bond strengths were determined using a universal testing machine. The enamel and dentin data sets were subjected to separate analysis of variance and Tukey's tests. Scanning electron microscopy was used to evaluate the effects of each system on enamel.   Mean shear bond strengths to enamel ranged from 18.1 MPa for Xeno IV to 41.0 MPa for OptiBond FL. On dentin, the means ranged from 33.3 MPa for OptiBond FL to 47.1 MPa for Clearfil SE Bond. OptiBond XTR performed as well as Clearfil SE Bond on dentin and as well as OptiBond FL on enamel. Field emission scanning electron microscope revealed that OptiBond XTR produced an enamel etch pattern that was less defined than that of OptiBond FL (37.5% phosphoric acid) but more defined than that of Clearfil SE Bond or Xeno IV.   The new two-step self-etch adhesive system formed excellent bonds to enamel and dentin in vitro. OptiBond XTR, a new two-step self-etch adhesive system, is a promising material for bonding to enamel as well as to dentin. © 2011 Wiley Periodicals, Inc.

  15. Enamel and dentine demineralization by a combination of starch and sucrose in a biofilm – caries model

    Directory of Open Access Journals (Sweden)

    Juliana Nunes BOTELHO

    2016-01-01

    Full Text Available Abstract Sucrose is the most cariogenic dietary carbohydrate and starch is considered non-cariogenic for enamel and moderately cariogenic for dentine. However, the cariogenicity of the combination of starch and sucrose remains unclear. The aim of this study was to evaluate the effect of this combination on Streptococcus mutans biofilm composition and enamel and dentine demineralization. Biofilms of S. mutans UA159 were grown on saliva-coated enamel and dentine slabs in culture medium containing 10% saliva. They were exposed (8 times/day to one of the following treatments: 0.9% NaCl (negative control, 1% starch, 10% sucrose, or 1% starch and 10% sucrose (starch + sucrose. To simulate the effect of human salivary amylase on the starch metabolization, the biofilms were pretreated with saliva before each treatment and saliva was also added to the culture medium. Acidogenicity of the biofilm was estimated by evaluating (2 times/day the culture medium pH. After 4 (dentine or 5 (enamel days of growth, biofilms (n = 9 were individually collected, and the biomass, viable microorganism count, and polysaccharide content were quantified. Dentine and enamel demineralization was assessed by determining the percentage of surface hardness loss. Biofilms exposed to starch + sucrose were more acidogenic and caused higher demineralization (p < 0.0001 on either enamel or dentine than those exposed to each carbohydrate alone. The findings suggest that starch increases the cariogenic potential of sucrose.

  16. Effect of dentin bonding agent diffusing through dentin slices on the reactive oxygen species production and apoptosis of pulpal cells

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    Bor-Shiunn Lee

    2015-04-01

    Conclusion: The three DBAs after diffusion through 0.2- or 0.5-mm dentin slice still exhibit cytotoxicity to dental pulp cells. However, the 0.5-mm dentin slice is found to be a better barrier than the 0.2-mm dentin slice to protect dental pulp cells from DBA-induced cytotoxicity.

  17. Mini-interfacial Fracture Toughness of a Multimode Adhesive Bonded to Plasma-treated Dentin.

    Science.gov (United States)

    Ayres, Ana Paula Almeida; Pongprueksa, Pong; De Munck, Jan; Gré, Cristina Parise; Nascimento, Fábio Dupart; Giannini, Marcelo; Van Meerbeek, Bart

    2017-01-01

    To investigate the bonding efficacy of a multimode adhesive to plasma-treated and -untreated (control) dentin using a mini-interfacial fracture toughness (mini-iFT) test. Twenty human molars were used in a split-tooth design (n = 10). The adhesive Scotchbond Universal (SBU; 3M ESPE) was applied in etch-and-rinse (E&R) and self-etch (SE) modes. Mid-coronal dentin was exposed and covered with a standardized smear layer ground to 320 grit. One half of each dentin surface received 15 s of non-thermal atmospheric plasma (NTAP), while the other half was covered with a metallic barrier and kept untreated. Following the E&R mode, dentin was plasma treated immediately after phosphoric acid etching. SBU and a resin-based composite were applied to dentin following the manufacturer's instructions. Six mini-iFT specimens were prepared per tooth (1.5 x 2.0 x 16 to 18 mm), and a single notch was prepared at the adhesive-dentin interface using a 150-μm diamond blade under water cooling. Half of the mini-iFT specimens were immediately loaded until failure in a 4-point bending test, while the other half were first stored in distilled water for 6 months. After testing, the exact dimensions of the notch were measured with a measuring optical microscope, from which ΚIc was determined. Three-way ANOVA revealed higher mini-iFT for SBU applied in E&R than SE mode for both storage times, irrespective of NTAP treatment. Overall, mini-iFT did not decrease for any of the experimental groups upon 6-month aging, while plasma treatment did not show a direct beneficial effect on mini-iFT of SBU applied in either E&R or SE mode.

  18. Sealing ability and bond strength of four contemporary adhesives to enamel and to dentine.

    Science.gov (United States)

    Atash, R; Vanden Abbeele, A

    2005-12-01

    To compare the shear bond strength and microleakage of four adhesive systems to the enamel and dentine of primary bovine teeth. 120 bovine primary mandibular incisors were collected and stored in an aqueous 1% chloramine solution at room temperature for no longer than 3 months after extraction (80 for shear bond testing and 40 for microleakage evaluation). The adhesives tested were Clearfil SE bond (SE), Adper Prompt L Pop (LP), Xeno III (XE), and Prime and Bond NT (PB). For shear bond strength testing the specimens were wet ground to 600 grit SiC paper to expose a flat enamel or dentine surface. After bonding and restoration with Dyract AP (DAP), the teeth were subjected to shear stress using a universal testing machine. For microleakage evaluation, facial class V cavities were prepared half in enamel and half in cementum. All cavities were restored with DAP. After thermocycling and immersion in 2% methylene blue, the dye penetration was evaluated under a stereomicroscope. All data were analysed by Chi-square tests or Fisher's tests when adapted in order to determine the significant differences between groups. Results were considered as significant for p enamel 11.06 to 5.34, in decreasing order SE, LP, XE and PB and on dentine 10.47 to 4.74, in decreasing order SE, XE, LP and PB. Differences in bond strengths between the four systems on enamel and dentine were all statistically significant, excepted for XE vs LP (shear bond at dentine). No significant differences were recorded in the microleakage degree between the four adhesive systems on enamel and on dentine (p > 0.0.5). The highest shear bond strength was achieved by Clearfil SE bond and the lowest by Prime and Bond NT. There was no significant difference concerning the sealing ability of the four adhesive systems.

  19. Comparison of shear bond strength between unfilled resin to dry enamel and dentin bonding to moist and dry enamel

    Directory of Open Access Journals (Sweden)

    Yasini E.

    2005-05-01

    Full Text Available Statement of Problem: The use of dentine bondings on enamel and dentin in total etch protocols has recently become popular. Unfilled resin is hydrophobic and dentin bonding is hydrophilic in nature. This chemical difference could be effective in enamel bonding process. Purpose: The aim of this study was to compare the shear bond strength of unfilled resin to dry enamel and dentin bonding to dry and moist enamel. Materials and Methods: In this experimental study, a total of 30 incisor teeth were used. The specimens were randomly assigned to three groups of 10. 37% phosphoric acid etchant was applied to the enamel surfaces in each group for 15 seconds, rinsed with water for 20 seconds and dried for 20 seconds with compressed air in groups one and two. After conditioning, group 1 received unfilled resin (Margin Bond, Colten and group 2 received dentin bonding (Single Bond, 3M and in group 3 after conditioning and rinsing with water, a layer of dentin bonding (Single Bond was applied on wet enamel. The enamel and dentin bonding were light cured for 20 seconds. A ring mold 3.5 mm in diameter and 2 mm height was placed over the specimens to receive the composite filling material (Z100, 3M. The composite was cured for 40 seconds. The specimens were thermocycled and shear bond strengths were determined using an Instron Universal Testing Machine. The findings were analyzed by ANOVA One-Way and Tukey HSD tests. Results: Shear bond strength of dentin bonding to dry enamel was significantly less than unfilled resin to dry enamel (P<0.05. There was no significant difference between the bond strength of dentin bonding to moist and dry enamel. In addition bond strength of dentin bonding to wet enamel was not significantly different from unfilled resin to dry enamel. Conclusion: Based on the findings of this study, it is suggested that enamel surface should remain slightly moist after etching before bonding with single bond but when using unfilled resin, the

  20. Amalgam shear bond strength to dentin using single-bottle primer/adhesive systems.

    Science.gov (United States)

    Cobb, D S; Denehy, G E; Vargas, M A

    1999-10-01

    To evaluate the in vitro shear bond strengths (SBS) of a spherical amalgam alloy (Tytin) to dentin using several single-bottle primer/adhesive systems both alone: Single Bond (SB), OptiBond Solo (Sol), Prime & Bond 2.1 (PB), One-Step (OS) and in combination with the manufacturer's supplemental amalgam bonding agent: Single Bond w/3M RelyX ARC (SBX) and Prime & Bond 2.1 w/Amalgam Bonding Accessory Kit (PBA). Two, three-component adhesive systems, Scotchbond Multi-Purpose (SBMP) and Scotchbond Multi-Purpose Plus w/light curing (S + V) and w/o light curing (S+) were used for comparison. One hundred eight extracted human third molars were mounted lengthwise in phenolic rings with acrylic resin. The proximal surfaces were ground to expose a flat dentin surface, then polished to 600 grit silicon carbide paper. The teeth were randomly assigned to 9 groups (n = 12), and dentin surfaces in each group were treated with an adhesive system according to the manufacturer's instructions, except for S + V specimens, where the adhesive was light cured for 10 s before placing the amalgam. Specimens were then secured in a split Teflon mold, having a 3 mm diameter opening and amalgam was triturated and condensed onto the treated dentin surfaces. Twenty minutes after condensation, the split mold was separated. Specimens were placed in distilled water for 24 hrs, then thermocycled (300 cycles, between 5 degrees C and 55 degrees C, with 12 s dwell time). All specimens were stored in 37 degrees C distilled water for 7 days, prior to shear strength testing using a Zwick Universal Testing Machine at a cross-head speed of 0.5 mm/min. The highest to the lowest mean dentin shear bond strength values (MPa) for the adhesive systems tested were: S + V (10.3 +/- 2.3), SBX (10.2 +/- 3.5), PBA, (6.4 +/- 3.6), SOL (5.8 +/- 2.5), SBMP (5.7 +/- 1.8), S+ (4.8 +/- 2.3), PB (2.7 +/- 2.6), SB (2.7 +/- 1.1) and OS (2.5 +/- 1.8). One-way ANOVA and Duncan's Multiple Range Test indicated significant

  1. The acid-base resistant zone in three dentin bonding systems.

    Science.gov (United States)

    Inoue, Go; Nikaido, Toru; Foxton, Richard M; Tagami, Junji

    2009-11-01

    An acid-base resistant zone has been found to exist after acid-base challenge adjacent to the hybrid layer using SEM. The aim of this study was to examine the acid-base resistant zone using three different bonding systems. Dentin disks were applied with three different bonding systems, and then a resin composite was light-cured to make dentin disk sandwiches. After acid-base challenge, the polished surfaces were observed using SEM. For both one- and two-step self-etching primer systems, an acid-base resistant zone was clearly observed adjacent to the hybrid layer - but with differing appearances. For the wet bonding system, the presence of an acid-base resistant zone was unclear. This was because the self-etching primer systems etched the dentin surface mildly, such that the remaining mineral phase of dentin and the bonding agent yielded clear acid-base resistant zones. In conclusion, the acid-base resistant zone was clearly observed when self-etching primer systems were used, but not so for the wet bonding system.

  2. Effect of Green Tea Extract on the Treatment of Dentin Erosion: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    M Mirkarimi

    2012-01-01

    Full Text Available Objective: The aim of this study was to analyze the impact of green tea on dentin erosion.Materials and Methods: Twelve extracted sound human premolars were immersed in Coca Cola with a pH of 2.8 for 5 minutes. The surface microhardness was measured with a Knoop diamond under a load of 50gr/10s. The teeth were immersed in green tea (Camellia sinensis solution for one minute. The microhardness values were measured again and compared with pretreatment values by the Wilcoxon test. Three eroded teeth, which were treated with green tea, were evaluated under scanning electron microscope.Results: The mean ± SD of microhardness values before and after immersion in green tea were 46.5±2.79 and 54.5±4.4, respectively with statistically significant differences between the two measurements (P<0.01. In SEM evaluation there was an improvement in eroded dentin appearance and there were deposits on the dentin surface.Conclusion: Green tea (Camellia sinensis increased the microhardness of eroded dentin and improved the eroded texture.

  3. Shear Bond Strengths and Morphological Evaluation of Filled and Unfilled Adhesive Interfaces to Enamel and Dentine

    Science.gov (United States)

    Mortazavi, Vajihesadat; Fathi, Mohammadhosein; Ataei, Ebrahim; Khodaeian, Niloufar; Askari, Navid

    2012-01-01

    In this laboratory study shear bond strengths of three filled and one unfilled adhesive systems to enamel and dentine were compared. Forty-eight extracted intact noncarious human mandibular molars were randomly assigned to two groups of 24 one for bonding to enamel and the other for bonding to dentine. Buccal and lingual surfaces of each tooth were randomly assigned for application of each one of filled (Prime & Bond NT (PBNT), Optibond Solo Plus (OBSP), and Clearfil SE Bond (CSEB)) and unfilled (Single Bond (SB)) adhesive systems (n = 12). A universal resin composite was placed into the translucent plastic cylinders (3 mm in diameter and 2 mm in length) and seated against the enamel and dentine surfaces and polymerized for 40 seconds. Shear bond strength was determined using a universal testing machine, and the results were statistically analyzed using two-way ANOVA, one-way ANOVA, t-test, and Tukey HSD post hoc test with a 5% level of significance.There were no statistically significant differences in bond strength between the adhesive systems in enamel, but CSEB and SB exhibited significantly higher and lower bond strength to dentine, respectively, than the other tested adhesive systems while there were no statistically significant differences between PBNT and OBSP. PMID:23209471

  4. Shear Bond Strengths and Morphological Evaluation of Filled and Unfilled Adhesive Interfaces to Enamel and Dentine

    Directory of Open Access Journals (Sweden)

    Vajihesadat Mortazavi

    2012-01-01

    Full Text Available In this laboratory study shear bond strengths of three filled and one unfilled adhesive systems to enamel and dentine were compared. Forty-eight extracted intact noncarious human mandibular molars were randomly assigned to two groups of 24 one for bonding to enamel and the other for bonding to dentine. Buccal and lingual surfaces of each tooth were randomly assigned for application of each one of filled (Prime & Bond NT (PBNT, Optibond Solo Plus (OBSP, and Clearfil SE Bond (CSEB and unfilled (Single Bond (SB adhesive systems (n=12. A universal resin composite was placed into the translucent plastic cylinders (3 mm in diameter and 2 mm in length and seated against the enamel and dentine surfaces and polymerized for 40 seconds. Shear bond strength was determined using a universal testing machine, and the results were statistically analyzed using two-way ANOVA, one-way ANOVA, t-test, and Tukey HSD post hoc test with a 5% level of significance.There were no statistically significant differences in bond strength between the adhesive systems in enamel, but CSEB and SB exhibited significantly higher and lower bond strength to dentine, respectively, than the other tested adhesive systems while there were no statistically significant differences between PBNT and OBSP.

  5. Micro-shear bond strength of resin cement to dentin after application of desensitizing toothpastes.

    Science.gov (United States)

    Bavbek, Andac Barkin; Goktas, Baris; Cekic-Nagas, Isil; Egilmez, Ferhan; Ergun, Gulfem; Eskitascioglu, Gurcan

    2013-01-01

    The aim of the study was to evaluate the effect of three desensitizing toothpastes on bonding of resin cements to dentin. The occlusal surfaces of 72 maxillary third molars were ground to obtain flat dentin surfaces and then divided into three groups according to three desensitizing toothpastes used: Sensodyne Rapid Relief (GlaxoSmithKline, SmithKline Beecham Ltd., Slough, UK), Signal Sensitive Expert (Unilever Sanayi ve Ticaret Türk A.Ş., Ümraniye, İstanbul, Turkey) and Colgate Sensitive Pro-Relief (Colgate Palmolive, New York, NY). Following bonding of the resin cement (Clearfil™ SA Cement, Kuraray Co, Osaka, Japan) to dentin, the specimens were light cured for 40 s with a LED (Elipar S10, 3M Espe, St. Paul, MN). The strength measurements were accomplished with a micro-shear testing machine (Bisco, Schaumburg, IL) at a cross-head speed of 0.5 mm/min until the failure occurs. Failure modes were examined using a stereomicroscope and scanning electron microscope. The data were analyzed with one-way analysis of variance (ANOVA) and Tukey HSD test (α = 0.05). ANOVA revealed that the application of desensitizing toothpastes had significant effects on bond strength of the resin cement tested to dentin (p < 0.05). Mixed failures were observed in all of the groups. The use of a desensitizing toothpaste before cementation might alter the bond strength of adhesively luted restorations.

  6. Effect of green tea as a protective measure against dental erosion in coronary dentine

    Directory of Open Access Journals (Sweden)

    Maria Denise Rodrigues DE MORAES

    2016-01-01

    Full Text Available Abstract The aim of this study was to evaluate the effect of green tea as a protective measure on eroded dentin. Disks of human coronary dentin were selected based on surface hardness and randomly assigned to 3 groups (n = 10: DW - distilled water, CHX - 0.2% chlorhexidine digluconate, and GT - green tea. The disks were allowed to acquire pellicle for 2 hours and were then subjected to 3 cycles per day of demineralization (C6H8O7 0.05 M, pH 3.75, 60 s, treatment (DW or CHX or GT, 5 min and remineralization (artificial saliva, 60 min over a period of 3 days. Changes in the dentin were determined by loss of surface hardness (%SHL and mechanical profilometry analysis at the end of each day. Data were analyzed by two-way ANOVA followed by Tukey’s test for %SHL and profilometry (p 0.05. A significant difference was observed between DW and GT treatments for wear and roughness measurements (p < 0.05. The green tea extract solution was able to reduce the wear and roughness caused by dentin erosion under the conditions of this study.

  7. Studies of micromorphology and current efficiency of zinc electrodeposited from flowing chloride electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Mc Vay, Laura [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States); Tobias, Charles W. [Univ. of California, Berkeley, CA (United States)

    1986-05-01

    Results of a study of the micromorphology and current efficiency of zinc electrodeposited from flowing, acidic chloride solutions are reported. The effects of six variables were examined: flow rate, current density, zinc and hydrogen ion concentration, concentrations of nickel, iron and cadmium impurity ions, and the nature of the substrate. The development of micromorphology was studied in-situ by means of videomicrography and ex-situ by means of scanning electron microscopy. This investigation focused on the formation of grooved deposits, which are found under a wide range of deposition conditions. The major conclusions of this study are: the most important variable determining whether grooved deposits form is the interfacial concentration; large protrusions orient themselves parallel to the flow direction with the orientation starting upstream and progressing downstream; large protrusions become ridges due to growth of the highest current density portions of the electrode under mass transport control. The current efficiency was measured using EDTA titration and weight measurements. The fraction of the current taken by zinc deposition increased with zinc concentration, ranging up to 100%, and decreased with pH. The efficiency of zinc deposition was affected by the flow rate and the substrate employed. Impurities lowered the current efficiency.

  8. X-ray microtomography in the micromorphologic characterization of soil submitted to different management

    International Nuclear Information System (INIS)

    Passoni, Sabrina

    2013-01-01

    The X-ray computed microtomography (CT) represents a non-invasive technique that can be used with success to analyze physical properties by the soil scientists without destroying the structure of the soil. The technique has as advantage over conventional methods the characterization of the soil porous system in three dimensions, which allow morphological property analyses such as connectivity and tortuosity of the pores. However, as the soil is a non-homogeneous and complex system, the CT technique needs specific methodologies for digital image processing, mainly during the segmentation procedure. The objectives of this work were: 1) to develop a methodology for microtomographic digital image processing; 2) to characterize the soil structure by using micromorphology analysis of samples submitted to non-tillage and conventional systems collected in three distinct layers (0-10, 10-20 and 20-30 cm); and 3) to identify possible changes in the porous system of the soil analyzed due to the effect of different management systems. The use of the CT technique and the procedures adopted for microtomographic digital image processing show to be efficient for the micromorphologic characterization of soil porous system. Soil under non-tillage system presented the best results from the agricultural point of view regarding porosity, total number of pores, connectivity and tortuosity in comparison to the conventional tillage. (author)

  9. Photochemical Formation and Transformation of Birnessite: Effects of Cations on Micromorphology and Crystal Structure.

    Science.gov (United States)

    Zhang, Tengfei; Liu, Lihu; Tan, WenFeng; Suib, Steven L; Qiu, Guohong; Liu, Fan

    2018-05-24

    As important components with excellent oxidation and adsorption activity in soils and sediments, manganese oxides affect the transportation and fate of nutrients and pollutants in natural environments. In this work, birnessite was formed by photocatalytic oxidation of Mn2+aq in the presence of nitrate under solar irradiation. The effects of concentrations and species of interlayer cations (Na+, Mg2+, and K+) on birnessite crystal structure and micromorphology were investigated. The roles of adsorbed Mn2+ and pH in the transformation of the photosynthetic birnessite were further studied. The results indicated that Mn2+aq was oxidized to birnessite by superoxide radicals (O2•-) generated from the photolysis of NO3- under UV irradiation. The particle size and thickness of birnessite decreased with increasing cation concentration. The birnessite showed a plate-like morphology in the presence of K+, while exhibited a rumpled sheet-like morphology when Na+ or Mg2+ was used. The different micromorphologies of birnessites could be ascribed to the position of cations in the interlayer. The adsorbed Mn2+ and high pH facilitated the reduction of birnessite to low-valence manganese oxides including hausmannite, feitknechtite, and manganite. This study suggests that interlayer cations and Mn2+ play essential roles in the photochemical formation and transformation of birnessite in aqueous environments.

  10. The nest growth of the neotropical mound-building termite, Cornitermes cumulans: a micromorphological analysis.

    Science.gov (United States)

    Cosarinsky, Marcela I

    2011-01-01

    The nests of Cornitermes cumulans K. (Isoptera: Termitidae), a very common termite in South American grasslands, display notable morphological transformations during the development of the colony. Young colonies inhabit small subterranean nests that develop into large, conspicuous, epigean mounds, inhabited by very populous colonies. Those macromorphological transformations are accompanied by micromorphological changes occurring gradually in the nest walls. The micromorphological changes during nest development described in the present study expand on previous macromorphological descriptions by explaining the re-organization of the soil components during nest growth. In subterranean nests, walls are composed of piles of lensshaped aggregates of soil material, each one surrounded by a thin organic coating. As the nest grows, mound walls are constructed by disassembling this first lenticular structure and rearranging the materials in a new fabric, where sand grains are loosely distributed among soil microaggregates of organic matter and clay. This is also a temporary construction, because the walls of large nests are composed of a porous mass of sands densely cemented with organic matter and clay in the mound, and a compact mass of the same components in the floor.

  11. The influence of metal Mg on micro-morphology and crystallinity of spherical hexagonal boron nitride

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ning, E-mail: zhangning5832@163.com; Liu, Huan; Kan, Hongmin; Wang, Xiaoyang; Long, Haibo; Zhou, Yonghui

    2015-08-15

    Highlights: • The action mechanism of Mg to the synthesis of spherical BN was explored. • The influence of Mg content on the crystallinity of h-BN powders was studied. • Even if not added any template, the spherical h-BN could be prepared. - Abstract: This search used the boric acid and borax as a source of boron, urea as a nitrogen source, Mg as metal catalyst, and thus prepared different micro-morphology and crystallinity hexagonal boron nitride powders under a flowing ammonia atmosphere at a nitriding temperature of 750 °C. The effect of Mg content on the crystallinity and micro-morphology of hexagonal boron nitride powders was studied, and the Mg action mechanism was explored. Without the added surfactant, the graphitization index (GI) was 6.87, and the diameter of the spherical h-BN was bigger. When the added Mg were 0.1 g, 0.3 g, 0.5 g and 0.7 g, the (GI) decreased to 6.04, 5.67, 4.62 and 4.84, respectively. When the Mg content was higher (0.9 g), GI value increased rapidly, and the crystallinity became bad. When the Mg content was 0.5 g, the dispersion of h-BN powders was at its optimum and refinement apparently, and the crystallinity at its highest.

  12. Floral micromorphology of the genus Ensete Bruce ex Horan. (Musaceae in Thailand

    Directory of Open Access Journals (Sweden)

    Wandee Inta

    2015-09-01

    Full Text Available To fulfil scarce and incomplete information on floral micromorphology of ensets (Ensete Bruce ex Horan. in the banana family (Musaceae, a comparative anatomical study of two species: E. glaucum (Roxb. Cheesman and E. superbum (Roxb. Cheesman, native to Thailand was conducted. It was found that, apart from five fertile stamens presented in other members of the Musaceae family, both ensets possess a short staminode. It is suggested from this investigation that six is the basic number of Ensete androecial whorl and the taxa could secure the most primitive status within the family and the Zingiberales order, of which stamen numbers are reduced. The results also indicated that the vascular bundle position in compound tepal, the vascular patterns in vascular zone of ovary and cell shapes of stigma epidermis and the ovary cortex are of systematic significance in conjunction with pollen size and exine ornamentation. These useful micromorphological characters can be further applied for identification of other Ensete species distribute elsewhere in the world.

  13. Primum non nocere - The effects of sodium hypochlorite on dentin as used in endodontics.

    Science.gov (United States)

    Gu, Li-Sha; Huang, Xue-Qing; Griffin, Brandon; Bergeron, Brian R; Pashley, David H; Niu, Li-Na; Tay, Franklin R

    2017-10-01

    The medical literature is replete with the maxim 'primum non nocere', cautioning health care providers to avoid doing any harm to human subjects in their delivery of medical care. Sodium hypochlorite (NaOCl) is a well-established irrigant for root canal treatment because of its antimicrobial and organic tissue remnant dissolution capability. However, little is known about the deleterious effect of this strong oxidizing agent on the integrity of human mineralized dentin. Iatrogenically-induced loss of dentin integrity may precipitate post-treatment root fracture and has potential medico-legal complications. In the present work, transmission electron microscopy provided evidence for collagen destruction in the surface/subsurface of dentin treated with high NaOCl concentrations and long contact times. Size exclusion chromatography showed that the hypochlorite anion, because of its small size, penetrated the water compartments of apatite-encapsulated collagen fibrils, degraded the collagen molecules and produced a 25-35µm thick, non-uniform "ghost mineral layer" with enlarged, coalesced dentinal tubules and their lateral branches. Fourier transform-infrared spectroscopy identified increases in apatite/collagen ratio in NaOCl-treated dentin. The apatite-rich, collagen-sparse dentin matrix that remained after NaOCl treatment is more brittle, as shown by the reductions in flexural strength. Understanding the deleterious effects of NaOCl on mineralized dentin enables one to balance the risks and benefits in using high NaOCl concentrations for lengthy periods in root canal debridement. Delineating the mechanism responsible for such a phenomenon enables high molecular weight, polymeric antimicrobial and tissue dissolution irrigants to be designed that abides by the maxim of 'primum non nocere' in contemporary medical practices. The antimicrobial and tissue-dissolution capacities of NaOCl render it a well-accepted agent for root canal debridement. These highly desirable

  14. Assessment of radicular dentin permeability after irradiation with CO2 laser and endodontic irrigation treatments with thermal imaging

    Science.gov (United States)

    Cho, Heajin; Lee, Robert C.; Chan, Kenneth H.; Fried, Daniel

    2017-02-01

    Previous studies have demonstrated that the permeability changes due to the surface modification of dentin can be quantified via thermal imaging during dehydration. The CO2 laser has been shown to remove the smear layer and disinfect root canals. Moreover, thermal modification via CO2 laser irradiation can be used to convert dentin into a highly mineralized enamel-like mineral. The purpose of this study is to evaluate the radicular dentin surface modification after CO2 laser irradiation by measuring the permeability with thermal imaging. Human molar specimens (n=12) were sectioned into 4 axial walls of the pulp chamber and treated with either 10% NaClO for 1 minute, 5% EDTA for 1 minute, CO2 laser or none. The CO2 laser was operated at 9.4 μm with a pulse duration of 26 μs, pulse repetition rate of 300 Hz and a fluence of 13 J/cm2. The samples were dehydrated using an air spray for 60 seconds and imaged using a thermal camera. The resulting surface morphological changes were assessed using 3D digital microscopy. The images from digital microscopy confirmed melting of the mineral phase of dentin. The area enclosed by the time-temperature curve during dehydration, ▵Q, measured with thermal imaging increased significantly with treatments with EDTA and the CO2 laser (Ptreatment increases permeability of radicular dentin.

  15. Dentine hypersensitivity: real or imagined | Gbadebo | Nigerian ...

    African Journals Online (AJOL)

    Background: Dentine hypersensitivity is a common presentation of cause of pain and or discomfort with mastication which has been shown to affect the quality of life of the affected individual. It is also a common cause of presentation at the dental clinics. However, the cause, diagnosis and possible management to give relief ...

  16. Hydrofluoric acid on dentin should be avoided.

    NARCIS (Netherlands)

    Loomans, B.A.C.; Mine, A.; Roeters, F.J.M.; Opdam, N.J.M.; Munck, J. De; Huysmans, M.C.D.N.J.M.; Meerbeek, B. Van

    2010-01-01

    Hydrofluoric acid can be used for intra-oral repair of restorations. Contamination of tooth substrate with hydrofluoric acid cannot always be avoided. OBJECTIVES: To investigate the bonding effectiveness to hydrofluoric acid contaminated dentin by, micro-tensile bond strength testing, SEM and TEM.

  17. Penetration of amalgam constituents into dentine

    NARCIS (Netherlands)

    Scholtanus, Johannes D.; Ozcan, Mutlu; Huysmans, Marie-Charlotte D. N. J. M.

    Objectives: Amalgam restorations are replaced by adhesively placed composite resin restorations at an increasing rate. After the removal of amalgam dentine often shows marked dark discoloration that is attributed to the penetration of corrosion products from overlying amalgams. it is questioned

  18. Penetration of amalgam constituents into dentine.

    NARCIS (Netherlands)

    Scholtanus, J.D.; Ozcan, M.; Huysmans, M.C.D.N.J.M.

    2009-01-01

    OBJECTIVES: Amalgam restorations are replaced by adhesively placed composite resin restorations at an increasing rate. After the removal of amalgam dentine often shows marked dark discoloration that is attributed to the penetration of corrosion products from overlying amalgams. It is questioned

  19. The Possible Role of Dentin as a Piezoelectric Signal Generator by Determining the Elec-tromechanical Coupling Factor of Dentin

    Directory of Open Access Journals (Sweden)

    Atabak Shahidi

    2011-08-01

    Full Text Available Introduction: This article aimed at calculation of the electromechanical coupling factor of dentin which is an indicator of the effectiveness with which a piezoelectric material converts electrical en-ergy into mechanical energy, or vice versa. The hypothesis: The electro-mechanical coupling factor of dentin was determined in mode 11 and 33 by calculating the ratio of the produced electrical energy to the stored elastic energy in dentin under applied pressure. This study showed that the electromechanical coupling factor of dentin was affected by the direction of the applied force and the moisture content of dentin. Also dentin was a weak electromechanical energy converter which might be categorized as a piezoelectric pressure sensor.Evaluation of the hypothesis: Determination of the electrome-chanical coupling factor of dentin and its other piezoelectric constants is essential to investigate the biologic role of piezoelectricity in tooth.

  20. [Influence of different bonding agents on traction resistance of metal alloys to dentin].

    Science.gov (United States)

    Adabo, G L; da Silva Filho, F P; de Sá, D N; Rettondini, W C; dos Santos Cruz, C A

    1990-01-01

    They were casted pieces using three kinds of alloy (Ni-Cr, Ag-Sn and Cu-Al) with circular and smooth surface. They were cemented to human teeth, on occlusal surface, grounded at dentin level, through three different materials kind (zinc polycarboxylate cement, glassionomer cement and composite). After 24 hours storing, the samples were subjected to the tensile test. The results showed that the samples cemented with composite and the casts made with Ag-Sn alloy had higher bond strength.

  1. Bonding performance of self-adhesive flowable composites to enamel, dentin and a nano-hybrid composite.

    Science.gov (United States)

    Peterson, Jana; Rizk, Marta; Hoch, Monika; Wiegand, Annette

    2018-04-01

    This study aimed to analyze bond strengths of self-adhesive flowable composites on enamel, dentin and nano-hybrid composite. Enamel, dentin and nano-hybrid composite (Venus Diamond, Heraeus Kulzer, Germany) specimens were prepared. Three self-adhesive composites (Constic, DMG, Germany; Fusio Liquid Dentin, Pentron Clinical, USA; Vertise Flow, Kerr Dental, Italy) or a conventional flowable composite (Venus Diamond Flow, Heraeus Kulzer, Germany, etch&rinse technique) were applied to enamel and dentin. Nano-hybrid composite specimens were initially aged by thermal cycling (5000 cycles, 5-55 °C). Surfaces were left untreated or pretreated by mechanical roughening, Al 2 O 3 air abrasion or silica coating/silanization. In half of the composite specimens, an adhesive (Optibond FL, Kerr Dental, Italy) was used prior to the application of the flowable composites. Following thermal cycling (5000 cycles, 5-55 °C) of all specimens, shear bond strengths (SBS) and failure modes were analyzed (each subgroup n = 16). Statistical analysis was performed by ANOVAs/Bonferroni post hoc tests, Weibull statistics and χ 2 -tests (p composites on enamel and dentin were significantly lower (enamel: composite (enamel: 13.0 ± 5.1, dentin: 11.2 ± 6.3), and merely adhesive failures could be observed. On the nano-hybrid composite, SBS were significantly related to the pretreatment. Adhesive application improved SBS of the conventional, but not of the self-adhesive composites. The self-adhesive composite groups showed less cohesive failures than the reference group; the occurence of cohesive failures increased after surface pretreatment. Bonding of self-adhesive flowable composites to enamel and dentin is lower than bonding to a nano-hybrid composite.

  2. Characterization of Genipin-Modified Dentin Collagen

    Directory of Open Access Journals (Sweden)

    Hiroko Nagaoka

    2014-01-01

    Full Text Available Application of biomodification techniques to dentin can improve its biochemical and biomechanical properties. Several collagen cross-linking agents have been reported to strengthen the mechanical properties of dentin. However, the characteristics of collagen that has undergone agent-induced biomodification are not well understood. The objective of this study was to analyze the effects of a natural cross-linking agent, genipin (GE, on dentin discoloration, collagen stability, and changes in amino acid composition and lysyl oxidase mediated natural collagen cross-links. Dentin collagen obtained from extracted bovine teeth was treated with three different concentrations of GE (0.01%, 0.1%, and 0.5% for several treatment times (0–24 h. Changes in biochemical properties of NaB3H4-reduced collagen were characterized by amino acid and cross-link analyses. The treatment of dentin collagen with GE resulted in a concentration- and time-dependent pigmentation and stability against bacterial collagenase. The lysyl oxidase-mediated trivalent mature cross-link, pyridinoline, showed no difference among all groups while the major divalent immature cross-link, dehydro-dihydroxylysinonorleucine/its ketoamine in collagen treated with 0.5% GE for 24 h, significantly decreased compared to control (P< 0.05. The newly formed GE-induced cross-links most likely involve lysine and hydroxylysine residues of collagen in a concentration-dependent manner. Some of these cross-links appear to be reducible and stabilized with NaB3H4.

  3. The effect of radiation therapy on the mechanical and morphological properties of the enamel and dentin of deciduous teeth—an in vitro study

    International Nuclear Information System (INIS)

    Siqueira Mellara, Talitha de; Palma-Dibb, Regina Guenka; Oliveira, Harley Francisco de; Garcia Paula-Silva, Francisco Wanderley; Nelson-Filho, Paulo; Silva, Raquel Assed Bezerra da; Silva, Léa Assed Bezerra da; Queiroz, Alexandra Mussolino de

    2014-01-01

    To evaluate the effects of radiation therapy on deciduous teeth. The enamel and dentin microhardness (n = 12) was evaluated at 3 depths, both before (control) and after each 10 Gy of irradiation and up to a dose of 60 Gy. The morphology was evaluated via scanning electron microscopy (SEM) (n = 8). The data were analyzed using a two-way analysis of variance (ANOVA) and Tukey’s test (α = 5%). The enamel microhardness, as a whole, increased (p < 0.05) after a dose of 60 Gy (211.4 KH), mostly in the superficial enamel. There was a significant difference between the values of nonirradiated dentin microhardness (28.9 KH) compared with dentin that was irradiated with doses of 10 Gy (23.8 KH), 20 Gy (25.6 KH), 30 Gy (24.8 KH), and 40 Gy (25.7 KH) (p < 0.05). There was no difference between nonirradiated dentin and dentin irradiated with 60 Gy (p > 0.05). The highest mean value of microhardness (29.9 KH) (p < 0.05) was found in the middle dentin. The groups that were irradiated with doses of 30 and 60 Gy exhibited greater surface changes in their enamel and dentin compared with the nonirradiated groups for all regions, exhibiting an amorphous surface upon increase of the irradiation doses. The enamel microhardness increased at a dose of 60 Gy, whereas the value of the dentin microhardness did not change. A progressive disruption of enamel and dentin morphology was found with the increased radiation dose

  4. Indentation damage and mechanical properties of human enamel and dentin.

    Science.gov (United States)

    Xu, H H; Smith, D T; Jahanmir, S; Romberg, E; Kelly, J R; Thompson, V P; Rekow, E D

    1998-03-01

    Understanding the mechanical properties of human teeth is important to clinical tooth preparation and to the development of "tooth-like" restorative materials. Previous studies have focused on the macroscopic fracture behavior of enamel and dentin. In the present study, we performed indentation studies to understand the microfracture and deformation and the microcrack-microstructure interactions of teeth. It was hypothesized that crack propagation would be influenced by enamel rods and the dentino-enamel junction (DEJ), and the mechanical properties would be influenced by enamel rod orientation and tooth-to-tooth variation. Twenty-eight human third molars were used for the measurement of hardness, fracture toughness, elastic modulus, and energy absorbed during indentation. We examined the effect of enamel rod orientation by propagating cracks in the occlusal surface, and in the axial section in directions parallel and perpendicular to the occlusal surface. The results showed that the cracks in the enamel axial section were significantly longer in the direction perpendicular to the occlusal surface than parallel. The cracks propagating toward the DEJ were always arrested and unable to penetrate dentin. The fracture toughness of enamel was not single-valued but varied by a factor of three as a function of enamel rod orientation. The elastic modulus of enamel showed a significant difference between the occlusal surface and the axial section. It is concluded that the cracks strongly interact with the DEJ and the enamel rods, and that the mechanical properties of teeth are functions of microstructural orientations; hence, single values of properties (e.g., a single toughness value or a single modulus value) should not be used without information on microstructural orientation.

  5. Evaluation of the tensile bond strength of an adhesive system self-etching in dentin irradiated with Er:YAG laser

    International Nuclear Information System (INIS)

    Mello, Andrea Malluf Dabul de

    2000-01-01

    Since Buonocore (1955), several researchers have been seeking for the best adhesive system and treatment for the enamel and dentin surfaces. The use of the acid has been presented as one of the best techniques of dentin conditioning , because this promotes the removal of the 'smear layer and exhibition of dentinal structure, for a best penetration and micro- retention of the adhesive system. However, some conditioning methods have been appearing in the literature, for the substitution or interaction with the acid substances, as the laser. The objective of this work is to evaluate the tensile bond strength of the adhesive system self-etching' associated to a composed resin, in dentin surfaces conditioned with the Er:YAG laser. For this study, freshly extracted human teeth were used and in each one the dentinal surfaces , which were treated with three sandpapers of different granulations (120,400,600), to obtain a standard of the smear layer, before the irradiation of the laser and of the restoring procedure. After these procedures the specimens were storage in distilled water at 37 deg C for 24 hours. Soon after, they were submitted to the tensile strength test .After analyzing the results, we can concluded that the use of the Er:YAG laser can substitute the drill without the need of conditioning, when using the adhesive system 'self-etching' in the dentinal surfaces because there was a decline in the strength of adhesion in the groups conditioned with the laser. (author)

  6. New perspectives about molecular arrangement of primary and permanent dentin

    Energy Technology Data Exchange (ETDEWEB)

    Sanches Borges, Ana Flavia [Department of Dental Materials at Piracicaba Dental School, State University of Campinas, Piracicaba, SP (Brazil); Andrade Bitar, Renata [Biomedical Engineering, Valley of Paraiba University (UNIVAP) (Brazil); Kantovitz, Kamila Rosamilia [Department of Pediatric Dentistry at Piracicaba Dental School, State University of Campinas, Piracicaba, SP (Brazil); Bortollazo Correr, Americo [Department of Dental Materials at Piracicaba Dental School, State University of Campinas, Piracicaba, SP (Brazil); Martin, Airton Abrahao [Biomedical Engineering Post Graduation, Valley of Paraiba University (UNIVAP) (Brazil); Puppin-Rontani, Regina Maria [Department of Pediatric Dentistry at Piracicaba Dental School, State University of Campinas, Piracicaba, SP (Brazil)], E-mail: rmpuppin@fop.unicamp.br

    2007-12-30

    The dentin quality of primary and permanent teeth was inspected by Fourier transformed Raman spectroscopy (FT-Raman); scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) and hardness test. Middle dentin of crowns were reached by carbide bur abrading providing a uniform smear layer. Phosphoric acid was applied in order to simulate the etching of total etching adhesive systems. The groups were (n = 10): G1 (primary dentin smear layer); G2 (35% phosphoric acid etched primary dentin); G3 (permanent dentin smear layer); G4 (35% phosphoric acid etched permanent dentin). FT-Raman results were subjected to cluster analysis. SEM/EDS were made in order to add the data obtained by FT-Raman. The hardness data were subjected to ANOVA and Tukey test. FT-Raman showed differences among groups, either to organic or inorganic content. For the organic content, primary and permanent dentin became similar after the etching; conversely, the inorganic content showed differences for the two substrates. Hardness test showed no significant differences between primary and permanent dentin, before or after etching, but the etching decreased these values. The mineral content arrangement of primary dentin is different from permanent dentin, independently of the etching. The substrate type did no influence the hardness, but the etching decreased it.

  7. Shear bond strength of amalgam to dentin using different dentin adhesive systems

    Directory of Open Access Journals (Sweden)

    Farimah Sardari

    2012-01-01

    Full Text Available Background and Aims: The aim of this in vitro study was to assess the shear bond strength of amalgam to dentin using four dentin adhesive systems.Materials and Methods: One hundred human molars were selected. After enamel removal, a dentin cylinder with 3 mm thickness was prepared. Eighty specimens were resorted with amalgam and four dentin adhesive systems as follows (n=20: group 1, Scotch Bond Multi-Purpose; group 2, One Coat Bond; group 3, PQ1; and group 4, Panavia-F. In group 5, 20 specimens were resorted with amalgam and varnish as control group. The specimens were incubated at 37°C for 24 h. The shear bond strengths were then measured by using push out method. The data were analyzed by one-way ANOVA and post hoc Duncan's tests.Results: Mean values for bond strengths of test groups were as follows: group 1=21.03±8.9, group 2=23.47±9, group 3=13.16±8.8, group 4=20.07±8.9 and group 5=14.15±8.7 MPa±SD. One-way ANOVA showed the statistically significant difference between the bond strengths of five groups (P=0.001. Post hoc Duncan's test showed significant difference between groups 1and 3 (P=0.008, groups 1 and 5 (P=0.019, groups 2 and 5 (P=0.0008, groups 4 and 5 (P=0.042, and groups 3 and 4 (P=0.018.Conclusion: Results of this study showed that the bond strength of amalgam to dentin using One Coat Bond as dentin adhesive system was higher than that observed in other dentin adhesive systems.

  8. Do blood contamination and haemostatic agents affect microtensile bond strength of dual cured resin cement to dentin?

    Directory of Open Access Journals (Sweden)

    Kerem KiLiC

    2013-01-01

    Full Text Available Objective The purpose of this study was to evaluate the effects of blood contamination and haemostatic agents such as Ankaferd Blood Stopper (ABS and hydrogen peroxide (H2O2 on the microtensile bond strength between dual cured resin cement-dentin interface. Material and Methods Twelve pressed lithium disilicate glass ceramics were luted to flat occlusal dentin surfaces with Panavia F under the following conditions: Control Group: no contamination, Group Blood: blood contamination, Group ABS: ABS contamination Group H2O2: H2O2 contamination. The specimens were sectioned to the beams and microtensile testing was carried out. Failure modes were classified under stereomicroscope. Two specimens were randomly selected from each group, and SEM analyses were performed. Results There were significant differences in microtensile bond strengths (µTBS between the control and blood-contaminated groups (p0.05. Conclusions Contamination by blood of dentin surface prior to bonding reduced the bond strength between resin cement and the dentin. Ankaferd Blood Stoper and H2O2 could be used safely as blood stopping agents during cementation of all-ceramics to dentin to prevent bond failure due to blood contamination.

  9. Effect of chlorhexidine on the adhesion of dental cements in dentin

    International Nuclear Information System (INIS)

    Carvajal Villalobos, Marco Vinicio; Torres Montoya, Jeimy; Vindas Ramirez, Cinthya Carolina

    2013-01-01

    The effect of pretreatment with 0.2% chlorhexidine was evaluated in the adhesion strength in the dentin shear of three self-adhesive cements after one week of storage. 48 healthy teeth (premolars and molars) extracted were used. The occlusal surface was removed, exposing the dentin. Self-adhesive cements RelyX U100 (3M ESPE), SpeedCEM (Ivoclar) and BisCem (Bisco) were placed in an Ultradent cylindrical abutment (2mm diameter) in dentin pretreated with 0.2% chlorhexidine for 60 seconds and in dentin without treatment for 40 seconds. Removed the cylinder all the samples were photocured an additional 40 seconds. After one week, the adhesion force was in eight groups on a universal test machine at 0.01 cm/min. The ANOVA tests were used to analyze the data. The use of chlorhexidine at 0.2% did not affect the average strength of adhesion in shear, while the type of cement if the affection [es

  10. Solvent composition of one-step self-etch adhesives and dentine wettability.

    Science.gov (United States)

    Grégoire, Geneviève; Dabsie, Firas; Dieng-Sarr, Farimata; Akon, Bernadette; Sharrock, Patrick

    2011-01-01

    Our aim was to determine the wettability of dentine by four commercial self-etch adhesives and evaluate their spreading rate on the dentine surface. Any correlation with chemical composition was sought, particularly with the amount of solvent or HEMA present in the adhesive. The adhesives used were AdheSE One, Optibond All.In.One, Adper Easy Bond and XenoV. Chemical compositions were determined by proton nuclear magnetic resonance (NMR) spectroscopy of the adhesives dissolved in dimethylsulfoxide. Apparent contact angles for sessile drops of adhesives were measured on dentine slices as a function of time for up to 180s. The water contact angles were determined for fully polymerised adhesives. All adhesives were water-based with total solvent contents ranging from 27% to 73% for HEMA-free adhesives, and averaging 45% for HEMA containing adhesives. The contents in hydrophobic groups decreased as water contents increased. No differences were found in the adhesive contact angles after 180s even though the spreading rates were different for the products tested. Water contact angles differed significantly but were not correlated with HEMA or solvent presence. Manufacturers use different approaches to stabilise acid co-monomer ingredients in self-etch adhesives. Co-solvents, HEMA, or acrylamides without co-solvents are used to simultaneously etch and infiltrate dentine. A large proportion of water is necessary for decalcification action. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Bonding effectiveness of self-etch adhesives to dentin after 24 h water storage.

    Science.gov (United States)

    Sarr, Mouhamed; Benoist, Fatou Leye; Bane, Khaly; Aidara, Adjaratou Wakha; Seck, Anta; Toure, Babacar

    2018-01-01

    This study evaluated the immediate bonding effectiveness of five self-etch adhesive systems bonded to dentin. The microtensile bond strength of five self-etch adhesives systems, including one two-step and four one-step self-etch adhesives to dentin, was measured. Human third molars had their superficial dentin surface exposed, after which a standardized smear layer was produced using a medium-grit diamond bur. The selected adhesives were applied according to their respective manufacturer's instructions for μTBS measurement after storage in water at 37°C for 24 h. The μTBS varied from 11.1 to 44.3 MPa; the highest bond strength was obtained with the two-step self-etch adhesive Clearfil SE Bond and the lowest with the one-step self-etch adhesive Adper Prompt L-Pop. Pretesting failures mainly occurring during sectioning with the slow-speed diamond saw were observed only with the one-step self-etch adhesive Adper Prompt L-Pop (4 out of 18). When bonded to dentin, the self-etch adhesives with simplified application procedures (one-step self-etch adhesives) still underperform as compared to the two-step self-etch adhesive Clearfil SE Bond.

  12. Hybridization quality and bond strength of adhesive systems according to interaction with dentin

    Science.gov (United States)

    Salvio, Luciana Andrea; Hipólito, Vinicius Di; Martins, Adriano Luis; de Goes, Mario Fernando

    2013-01-01

    Objective: To evaluate the hybridization quality and bond strength of adhesives to dentin. Materials and Methods: Ten human molars were ground to expose the dentin and then sectioned in four tooth-quarters. They were randomly divided into 5 groups according to the adhesive used: Two single-step self-etch adhesives – Adper Prompt (ADP) and Xeno III (XE), two two-step self-etching primer systems – Clearfil SE Bond (SE) and Adhe SE (ADSE), and one one-step etch-and-rinse system – Adper Single Bond (SB). Resin composite (Filtek Z250) crown buildups were made on the bonded surfaces and incrementally light-cured for 20 s. The restored tooth-quarters were stored in water at 37°C for 24 h and then sectioned into beams (0.8 mm2 in cross-section). Maximal microtensile bond strength (μ-TBS) was recorded (0.5 mm/min in crosshead speed). The results were submitted to one-way ANOVA and Tukey's test (α = 0.05). Thirty additional teeth were used to investigate the hybridization quality by SEM using silver methenamine or ammoniacal silver nitrate dyes. Results: SE reached significantly higher μ-TBS (P 0.05), and between SB and ADP (P > 0.05); ADSE and XE were significantly higher than SB and ADP (P adhesives with dentin. The hybridization quality was essential to improve the immediate μ-TBS to dentin. PMID:24926212

  13. Morphology and thickness of the diffusion of resin through demineralized or unconditioned dentinal matrix

    Directory of Open Access Journals (Sweden)

    Arrais César Augusto Galvão

    2002-01-01

    Full Text Available The formation of a hybrid layer is the main bonding mechanism of current dentin-bonding systems. This study evaluated the morphology and thickness of the resin-infiltrated dentinal layer after the application of adhesive systems. The dentin-bonding agents were evaluated on flat dentinal preparations confected on the occlusal surfaces of human teeth. The test specimens were prepared and inspected under scanning electron microscopy at a magnification of X 2,000. The adhesive systems were responsible for different hybrid layer thicknesses (p < 0.05, and the mean values were: for Scotchbond MP Plus (SM, 7.41 ± 1.24mum; for Single Bond (SB, 5.55 ± 0.82mum; for Etch & Prime 3.0 (EP, 3.86 ± 1.17mum; and for Clearfil SE Bond (CB, 1.22 ± 0.45mum. The results suggest that the conventional three-step adhesive system (SM was responsible for the thickest hybrid layer, followed by the one-bottle adhesive (SB. The self-etching adhesives, EP and CB, produced the formation of the thinnest hybrid layers.

  14. Interfacial fracture of dentin adhesively bonded to quartz-fiber reinforced composite

    International Nuclear Information System (INIS)

    Melo, Renata M.; Rahbar, Nima; Soboyejo, Wole

    2011-01-01

    The paper presents the results of an experimental study of interfacial failure in a multilayered structure consisting of a dentin/resin cement/quartz-fiber reinforced composite (FRC). Slices of dentin close to the pulp chamber were sandwiched by two half-circle discs made of a quartz-fiber reinforced composite, bonded with bonding agent (All-bond 2, BISCO, Schaumburg) and resin cement (Duo-link, BISCO, Schaumburg) to make Brazil-nut sandwich specimens for interfacial toughness testing. Interfacial fracture toughness (strain energy release rate, G) was measured as a function of mode mixity by changing loading angles from 0 deg. to 15 deg. The interfacial fracture surfaces were then examined using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) to determine the failure modes when loading angles changed. A computational model was also developed to calculate the driving forces, stress intensity factors and mode mixities. Interfacial toughness increased from ∼ 1.5 to 3.2 J/m 2 when the loading angle increases from ∼ 0 to 15 deg. The hybridized dentin/cement interface appeared to be tougher than the resin cement/quartz-fiber reinforced epoxy. The Brazil-nut sandwich specimen was a suitable method to investigate the mechanical integrity of dentin/cement/FRC interfaces.

  15. Effect of different diode laser wavelengths on root dentin decontamination infected with Enterococcus faecalis.

    Science.gov (United States)

    Borges, Caroline Cristina; Estrela, Carlos; Lopes, Fabiane Carneiro; Palma-Dibb, Regina Guenka; Pecora, Jesus Djalma; De Araújo Estrela, Cyntia Rodrigues; Sousa-Neto, Manoel Damião de

    2017-11-01

    The objective of this study was to evaluate the antibacterial effect and the ultrastructural alterations of diode laser with different wavelengths (808nm and 970nm) and its association with irrigating solutions (2.5% sodium hypochlorite and 2% chlorhexidine) in root dentin contaminated by a five days biofilm. Thirteen uniradicular teeth were sectioned into 100 dentin intraradicular blocks. Initially, the blocks were immersed for 5min in 17% EDTA and washed with distilled water for 5min, then samples were sterilized for 30min at 120°C. The dentin samples were inoculated with 0.1mL of E. faecalis suspension in 5mL BHI (Brain Heart Infusion) and incubated at 37°C for 5days. After contamination, the specimens were distributed into ten groups (n=10) according to surface treatment: GI - 5mL NaOCl 2.5%, GII - 5mL NaOCl 2.5%+808nm diode (0.1W for 20s), GIII - 5mL NaOCl 2.5%+970nm diode (0.5W for 4s), GIV - 808nm diode (0.1W for 20s), GV - 970nm diode (0.5W for 4s), GVI - CHX 2%, GVII - CHX 2%+808nm diode (0.1W for 20s), GVIII - CHX 2%+970nm diode (0.5W for 4s), GIX - positive control and GX - negative control. Bacterial growth was analyzed by turbidity and optical density of the growth medium by spectrophotometry (nm). Then, the specimens were processed for analysis ultrastructural changes of the dentin surface by SEM. The data was subject to the One-way ANOVA test. GI (77.5±12.1), GII (72.5±12.2), GIII (68.7±8.7), GV (68.3±8.7), GVI (62.0±5.5) and GVII (67.5±3.3) were statistically similar and statistically different from GIV (58.8±25.0), GVIII (59.2±4.0) and control groups (pdiode laser; erosion of the intertubular dentin in blocks submitted to 808nm diode laser irradiation; and an increased erosion of the intertubular dentin when 2.5% NaOCl was associated to the different wavelengths lasers. All the therapeutic protocols were able to reduce the bacterial contingent in dentin blocks, and the association of diode laser and solutions did not significantly improve

  16. Adaptation of adhesive post and cores to dentin after in vitro occlusal loading: evaluation of post material influence.

    Science.gov (United States)

    Dietschi, Dider; Ardu, Stefano; Rossier-Gerber, Anne; Krejci, Ivo

    2006-12-01

    Fatigue resistance of post and cores is critical to the long term behavior of restored nonvital teeth. The purpose of this in vitro trial was to evaluate the influence of the post material's physical properties on the adaptation of adhesive post and core restorations after cyclic mechanical loading. Composite post and cores were made on endodontically treated deciduous bovine teeth using 3 anisotropic posts (made of carbon, quartz, or quartz-and-carbon fibers) and 3 isotropic posts (zirconium, stainless steel, titanium). Specimens were submitted to 3 successive loading phases--250,000 cycles at 50 N, 250,000 at 75 N, and 500,000 at 100 N--at a rate of 1.5 Hz. Restoration adaptation was evaluated under SEM, before and during loading (margins) and after test completion (margins and internal interfaces). Six additional samples were fabricated for the characterization of interface micromorphology using confocal microscopy. Mechanical loading increased the proportion of marginal gaps in all groups; carbon fiber posts presented the lowest final gap proportion (7.11%) compared to other stiffer metal-ceramic or softer fiber posts (11.0% to 19.1%). For internal adaptation, proportions of debonding between dentin and core or cement varied from 21.69% (carbon post) to 47.37% (stainless steel post). Debonding at the post-cement interface occurred only with isotropic materials. Confocal microscopy observation revealed that gaps were generally associated with an incomplete hybrid layer and reduced resin tags. Regardless of their rigidity, metal and ceramic isotropic posts proved less effective than fiber posts at stabilizing the post and core structure in the absence of the ferrule effect, due to the development of more interfacial defects with either composite or dentin.

  17. Porcine dentin sialoprotein glycosylation and glycosaminoglycan attachments.

    Science.gov (United States)

    Yamakoshi, Yasuo; Nagano, Takatoshi; Hu, Jan Cc; Yamakoshi, Fumiko; Simmer, James P

    2011-02-03

    Dentin sialophosphoprotein (Dspp) is a multidomain, secreted protein that is critical for the formation of tooth dentin. Mutations in DSPP cause inherited dentin defects categorized as dentin dysplasia type II and dentinogenesis imperfecta type II and type III. Dentin sialoprotein (Dsp), the N-terminal domain of dentin sialophosphoprotein (Dspp), is a highly glycosylated proteoglycan, but little is known about the number, character, and attachment sites of its carbohydrate moieties. To identify its carbohydrate attachment sites we isolated Dsp from developing porcine molars and digested it with endoproteinase Glu-C or pronase, fractionated the digestion products, identified fractions containing glycosylated peptides using a phenol sulfuric acid assay, and characterized the glycopeptides by N-terminal sequencing, amino acid analyses, or LC/MSMS. To determine the average number of sialic acid attachments per N-glycosylation, we digested Dsp with glycopeptidase A, labeled the released N-glycosylations with 2-aminobenzoic acid, and quantified the moles of released glycosylations by comparison to labeled standards of known concentration. Sialic acid was released by sialidase digestion and quantified by measuring β-NADH reduction of pyruvic acid, which was generated stoichiometrically from sialic acid by aldolase. To determine its forms, sialic acid released by sialidase digestion was labeled with 1,2-diamino-4,5-methyleneoxybenzene (DMB) and compared to a DMB-labeled sialic acid reference panel by RP-HPLC. To determine the composition of Dsp glycosaminoglycan (GAG) attachments, we digested Dsp with chondroitinase ABC and compared the chromotagraphic profiles of the released disaccharides to commercial standards. N-glycosylations were identified at Asn37, Asn77, Asn136, Asn155, Asn161, and Asn176. Dsp averages one sialic acid per N-glycosylation, which is always in the form of N-acetylneuraminic acid. O-glycosylations were tentatively assigned at Thr200, Thr216 and Thr

  18. Porcine dentin sialoprotein glycosylation and glycosaminoglycan attachments

    Directory of Open Access Journals (Sweden)

    Yamakoshi Fumiko

    2011-02-01

    Full Text Available Abstract Background Dentin sialophosphoprotein (Dspp is a multidomain, secreted protein that is critical for the formation of tooth dentin. Mutations in DSPP cause inherited dentin defects categorized as dentin dysplasia type II and dentinogenesis imperfecta type II and type III. Dentin sialoprotein (Dsp, the N-terminal domain of dentin sialophosphoprotein (Dspp, is a highly glycosylated proteoglycan, but little is known about the number, character, and attachment sites of its carbohydrate moieties. Results To identify its carbohydrate attachment sites we isolated Dsp from developing porcine molars and digested it with endoproteinase Glu-C or pronase, fractionated the digestion products, identified fractions containing glycosylated peptides using a phenol sulfuric acid assay, and characterized the glycopeptides by N-terminal sequencing, amino acid analyses, or LC/MSMS. To determine the average number of sialic acid attachments per N-glycosylation, we digested Dsp with glycopeptidase A, labeled the released N-glycosylations with 2-aminobenzoic acid, and quantified the moles of released glycosylations by comparison to labeled standards of known concentration. Sialic acid was released by sialidase digestion and quantified by measuring β-NADH reduction of pyruvic acid, which was generated stoichiometrically from sialic acid by aldolase. To determine its forms, sialic acid released by sialidase digestion was labeled with 1,2-diamino-4,5-methyleneoxybenzene (DMB and compared to a DMB-labeled sialic acid reference panel by RP-HPLC. To determine the composition of Dsp glycosaminoglycan (GAG attachments, we digested Dsp with chondroitinase ABC and compared the chromotagraphic profiles of the released disaccharides to commercial standards. N-glycosylations were identified at Asn37, Asn77, Asn136, Asn155, Asn161, and Asn176. Dsp averages one sialic acid per N-glycosylation, which is always in the form of N-acetylneuraminic acid. O-glycosylations were

  19. A comparative evaluation of the effect of dentin desensitizers on the retention of complete cast metal crowns

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    Saili M Chandavarkar

    2015-01-01

    Full Text Available Context: Desensitizers are used to reduce dentin hypersensitivity. They affect the surface texture of prepared dentin and may alter the retention of fixed restorations. Aims: The aim was to evaluate the effect of dentin desensitizers on the retention of complete cast metal crowns luted with glass ionomer cement. Subjects and Methods: Fifty freshly extracted human premolars were subjected to standardized tooth preparation (20° total convergence, 4 mm axial height with a computer numerically controlled machine. Individual cast metal crowns were fabricated from a base metal alloy. Dentin desensitizers included none (control, a glutaraldehyde (GLU based primer (Gluma desensitizer, casein phosphopeptide (CPP-amorphous calcium phosphate (ACP (GC Mousse, erbium, chromium: YSGG laser (Waterlase MD Turbo, Biolase and Pro-Argin (Colgate Sensitive Pro-Relief desensitizing polishing paste. After desensitization, crowns were luted with glass ionomer cement and kept for 48 h at 37°C in 100% relative humidity. The samples were tested using a universal testing machine by applying a load at a crosshead speed of 0.5 mm/min. Statistical Analysis Used: Statistical analysis included One-way ANOVA, followed by the Scheffe post-hoc test with P < 0.05. Results: All dentin desensitizers showed significantly different values: Pro-Argin (4.10 Megapascals [Mpa] < CPP-ACP (4.01 mpa < GLU based primer (3.87 Mpa < Virgin dentin (3.65 Mpa < LASER (3.37 Mpa. Conclusions : On comparing the effect of prepared virgin dentin, GLU based primer, CPP-ACP, LASER and Pro-Argin on the retention of complete cast metal crowns luted with glass ionomer cement on prepared teeth, it can be concluded that Pro-Argin and CPP-ACP showed the best retention in this in vitro study.

  20. Influence of different media on micromorphology of radiation synthesized poly(acrylamide-sodium acrylate) hydrogels

    International Nuclear Information System (INIS)

    Shan Jun; Chen Jie; Liu Zhanjun

    1998-01-01

    Poly(acrylamide-sodium acrylate) hydrogels were synthesized by 60 Co-γ ray radiation polymerization in aqueous solutions. The micromorphology of hydrogel samples dehydrated in the different alcohol media such as methanol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, and tert-butyl alcohol was observed by scanning electron microscope (SEM). The critical concentrations at volume phase transition of the hydrogels in the different alcohol medium-water solutions were obtained. The results indicate that the hydrogel samples dehydrated in methanol and in ethyl alcohol display bubble-film network structures, and those in n-propyl alcohol and in iso-propyl alcohol and in tert-butyl alcohol demonstrate the porous structures including the dense phase. The reason is discussed from the critical concentrations and solubility parameters of different alcohol media. (author)

  1. Real-time in vivo micromorphology and histopathology of choroidal osteoma using enhanced depth imaging

    Directory of Open Access Journals (Sweden)

    Rameez Hussain

    2015-01-01

    Full Text Available Choroidal osteoma is a usually unilateral benign tumor of the choroid composed of mature bone. Optical coherence tomography (OCT has been used to image osteoma for several years. With the advent of enhanced depth imaging (EDI feature of spectral-domain OCT (SD-OCT, better visualization of the morphology of choroidal lesions has been possible. Herein we present a case of choroidal osteoma in a 45-year-old woman, wherein in vivo morphology of the choroidal osteoma had been visualized using EDI technique of SD-OCT before and after performing photodynamic therapy. EDI OCT has proven to be a valuable noninvasive imaging modality, almost comparable to histopathological examination, for diagnosing choroidal osteomas and for providing an insight into the in vivo micromorphological changes occurring during the course of the disease.

  2. Micromorphology and anatomy of fruits and seeds of bitter melon (Momordica charantia L., Cucurbitaceae

    Directory of Open Access Journals (Sweden)

    Claudia Giuliani

    2016-03-01

    Full Text Available The aim of this paper is investigating the micromorphological properties of fruits and seeds in the food and medicinal plant Momordica charantia L. (Cucurbitaceae. A detailed anatomical description on cross-sections of immature fruits and seeds is reported for the first time. The fruit is characterized by a thin epicarp, a multi-layered mesocarp and by an inconspicuous endocarp. The seed-coat displays a pattern of organization in five tissues. These endomorphic features were compared and discussed with the results of previous investigations on other representatives of the genus Momordica. Since the structure of seed-coat is considered diacritical in the taxonomy of the genus, this report may offer a set of additional character useful for the characterization of the genus.

  3. MICROMORPHOLOGICAL STUDIES OF STARCH GRANULES IN SELECTED PROCESSED INDIGENOUS FLOUR OF SOUTH WESTERN NIGERIA

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    Adeniyi A. JAYEOLA

    2013-06-01

    Full Text Available Starch granules of yam stem tubers, plantain fruits and cassava root tubers were studied using the light microscope and then compared. Yam and plantain, both monocotyledons, had morphologically similar granules between locations, being mostly oval in shape while the granules of cassava, a dicot, were predominantly globular but varied between locations. Differences in processing methods between locations might be responsible for the observed variation in cassava granules. There is a suggestion that starch granule morphology might follow lineages in a broad sense. The unique micromorphology of cassava starch granule could make it easily detectable when adulterated, substituted or contaminated with yam or plantain granules and this could provide a cost effective clue in forensic determination.

  4. Anatomy and Micromorphology of Inula helenium subsp. orgyalis and I. ensifolia (Asteraceae from Turkey

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    Tulay AYTAS AKCIN

    2017-03-01

    Full Text Available Inula helenium L. subsp. orgyalis (Boiss. Grierson and Inula ensifolia L. were investigated anatomically and micromorphologically. The secretory cavities in the leaves and stem of both investigated taxa were located in the neighbourhood of the vascular bundles and in the rhizomes in the secondary cortex. The leaf mesophylls of investigated Inula taxa were homogeneous. Stomata were anomocytic in two species. The distribution and density of the eglandular and glandular trichomes provide information of taxonomical significance. Moreover, the cypselas of I. helenium L. subsp. orgyalis were homomorphic, whereas in I. ensifolia cypselas were heteromorphic. Additionally, the number of ribs, the shape of carpopodium and stylopodium were diagnostic taxonomic characters between the two taxa.

  5. Dentine tubule infection and endodontic therapy implications.

    Science.gov (United States)

    Oguntebi, B R

    1994-07-01

    A critical review of the literature suggests that the microenvironment of dentinal tubules appears to favour the selection of relatively few bacterial types irrespective of the aetiology of the infection process; coronal dental caries or pulpar necrosis. These bacteria may constitute an important reservoir from which root canal infection and reinfection may occur following pulp necrosis or during and after endodontic treatment. Previous studies of this microflora have utilized microbiological culture techniques which need to be supplemented by those that allow in situ demonstration as well as identification of the bacteria. Newer treatment strategies that are designed to eliminate this microflora must include agents that can penetrate the dentinal tubules and destroy these microorganisms, since they are located in an area beyond the host defence mechanisms where they cannot be reached by systemically administered antimicrobial agents.

  6. Effect of bur-cut dentin on bond strength using two all-in-one and one two-step adhesive systems.

    Science.gov (United States)

    Koase, Kaori; Inoue, Satoshi; Noda, Mamoru; Tanaka, Toru; Kawamoto, Chiharu; Takahashi, Akiko; Nakaoki, Yasuko; Sano, Hidehiko

    2004-01-01

    To compare the microtensile bond strength (MTBS) of two all-in-one adhesive systems and one experimental two-step self-etching adhesive system to two types of bur-cut dentin. Using one of the three adhesives, Xeno CF Bond (Xeno), Prompt L-Pop (PL), or the experimental two-step system ABF (ABF), resin composite was bonded to flat buccal and root dentin surfaces of eight extracted human premolars. These surfaces were produced using either regular-grit or superfine-grit diamond burs. After storage overnight in 37 degrees C water, the bonded specimens were sectioned into six or seven slices approximately 0.7 mm thick perpendicular to the bonded surface. They were then subjected to microtensile testing. The surfaces of the fractured specimens were observed microscopically to determine the failure mode. In addition, to observe the effect of conditioning, the two types of bur-cut dentin surfaces were conditioned with the adhesives, rinsed with acetone, and observed with SEM. When Xeno and PL were bonded to dentin cut with a regular-grit diamond bur, MTBS values were lower than to superfine bur-cut dentin, and failures occurred adhesively at the interface, whereas the experimental two-step adhesive showed no significant difference in microtensile bond strength between two differently cut surfaces. The all-in-one adhesives tested here improved bond strengths when bonded to superfine bur-cut dentin as a substrate, whereas the experimental two-step adhesive system showed unchanged bonding to both regular and superfine bur-cut dentin surfaces.

  7. In vivo Dentin Caries Model using Rat Molars

    OpenAIRE

    Takashi, HIGASHI; Junji, TAGAMI; Nobuhiro, HANADA; Cariology and Operative Dentistry, Department of Restorative Sciences, Tokyo Medical and Dental University; Cariology and Operative Dentistry, Department of Restorative Sciences, Tokyo Medical and Dental University; Department of Oral Science The National Institute of Infectious Diseases(NIID)

    2000-01-01

    Experimental dentinal caries was induced in rat molars which were inoculated orally with Streptococcus mutans and maintained on a carionenic diet 2000. After 30 days on the diet, the rats were sacrificed. The caries lesions were confirmed with a caries detector, then nanohardness determination of caries dentin were measured with nanoindentation. After hardness measurement, the lesion was examined by SEM and EDS. Dentin caries in sixteen fissures was induced among 20 fissures in the mandibular...

  8. Deformation Behavior of Human Dentin under Uniaxial Compression

    Directory of Open Access Journals (Sweden)

    Dmitry Zaytsev

    2012-01-01

    Full Text Available Deformation behavior of a human dentin under compression including size and rate effects is studied. No difference between mechanical properties of crown and root dentin is found. It is mechanically isotropic high elastic and strong hard tissue, which demonstrates considerable plasticity and ability to suppress a crack growth. Mechanical properties of dentin depend on a shape of samples and a deformation rate.

  9. Effect of smear layer deproteinization on bonding of self-etch adhesives to dentin: a systematic review and meta-analysis

    Science.gov (United States)

    Alshaikh, Khaldoan H.; Mahmoud, Salah H.

    2018-01-01

    Objectives The aim of this systematic review was to critically analyze previously published studies of the effects of dentin surface pretreatment with deproteinizing agents on the bonding of self-etch (SE) adhesives to dentin. Additionally, a meta-analysis was conducted to quantify the effects of the above-mentioned surface pretreatment methods on the bonding of SE adhesives to dentin. Materials and Methods An electronic search was performed using the following databases: Scopus, PubMed and ScienceDirect. The online search was performed using the following keywords: ‘dentin’ or ‘hypochlorous acid’ or ‘sodium hypochlorite’ and ‘self-etch adhesive.’ The following categories were excluded during the assessment process: non-English articles, randomized clinical trials, case reports, animal studies, and review articles. The reviewed studies were subjected to meta-analysis to quantify the effect of the application time and concentration of sodium hypochlorite (NaOCl) and hypochlorous acid (HOCl) deproteinizing agents on bonding to dentin. Results Only 9 laboratory studies fit the inclusion criteria of this systematic review. The results of the meta-analysis revealed that the pooled average microtensile bond strength values to dentin pre-treated with deproteinizing agents (15.71 MPa) was significantly lower than those of the non-treated control group (20.94 MPa). Conclusions In light of the currently available scientific evidence, dentin surface pretreatment with deproteinizing agents does not enhance the bonding of SE adhesives to dentin. The HOCl deproteinizing agent exhibited minimal adverse effects on bonding to dentin in comparison with NaOCl solutions. PMID:29765895

  10. Anatomical structure and surface micromorphology of tomatillo leaf and flower (Physalis ixocarpa Brot., Solanaceae

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    Barbara Dyki

    2014-01-01

    Full Text Available Tomatillo (Physalis ixocarpa Brot. is a newly introduced cultivated plant in Poland. Its anatomy was investigated in light and scanning electron microscopes. Tomatillo adult leaf had one layer of palisade parenchyma. The 1-2 cell layers of spongy parenchyma situated just below the palisade parenchyma showed large, tightly packed cells with great druses. The remaining spongy parenchyma was built of cells showing several extensions. Peculiarity of the sepals were the stomata situated on columns or hills formed of many cells. The petals had a very loose mesophyl. Their adaxial epidermis was composed of papillate cells. Such structure of the petal epidermis probably contributes to light dispersion and prevents glittering. There were several types of trichomes on the leaves, sepals and petals, some of them glandular and some simple. The large, very ramified, dendritic trichomes situated on the petals at the entry to the ovary might eventually protect it against excessive drying. The pollen grain was spherical, three-colpate. The style had a hollow channel inside. The stigma was of a wet, pa-pillate type. Sometimes thorny trichomes were found among papillae.

  11. Comprehensive proteomic analysis of human dentin

    Czech Academy of Sciences Publication Activity Database

    Jágr, Michal; Eckhardt, Adam; Pataridis, Statis; Mikšík, Ivan

    2012-01-01

    Roč. 120, č. 4 (2012), s. 259-268 ISSN 0909-8836 R&D Projects: GA ČR(CZ) GA203/08/1428; GA ČR(CZ) GAP206/12/0453 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : dentin * mass spectrometry * proteomics * tooth * two-dimensional gel electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.420, year: 2012

  12. Demineralized dentin matrix composite collagen material for bone tissue regeneration.

    Science.gov (United States)

    Li, Jianan; Yang, Juan; Zhong, Xiaozhong; He, Fengrong; Wu, Xiongwen; Shen, Guanxin

    2013-01-01

    Demineralized dentin matrix (DDM) had been successfully used in clinics as bone repair biomaterial for many years. However, particle morphology of DDM limited it further applications. In this study, DDM and collagen were prepared to DDM composite collagen material. The surface morphology of the material was studied by scanning electron microscope (SEM). MC3T3-E1 cells responses in vitro and tissue responses in vivo by implantation of DDM composite collagen material in bone defect of rabbits were also investigated. SEM analysis showed that DDM composite collagen material evenly distributed and formed a porous scaffold. Cell culture and animal models results indicated that DDM composite collagen material was biocompatible and could support cell proliferation and differentiation. Histological evaluation showed that DDM composite collagen material exhibited good biocompatibility, biodegradability and osteoconductivity with host bone in vivo. The results suggested that DDM composite collagen material might have a significant clinical advantage and potential to be applied in bone and orthopedic surgery.

  13. What's new in dentine bonding? Self-etch adhesives.

    Science.gov (United States)

    Burke, F J Trevor

    2004-12-01

    Bonding to dentine is an integral part of contemporary restorative dentistry, but early systems were not user-friendly. The introduction of new systems which have a reduced number of steps--the self-etch adhesives--could therefore be an advantage to clinicians, provided that they are as effective as previous adhesives. These new self-etch materials appear to form hybrid layers as did the previous generation of materials. However, there is a need for further clinical research on these new materials. Advantages of self-etch systems include, no need to etch and rinse, reduced post-operative sensitivity and low technique sensitivity. Disadvantages include, the inhibition of set of self- or dual-cure resin materials and the need to roughen untreated enamel surfaces prior to bonding.

  14. Dentinal tubule occluding capability of nano-hydroxyapatite; The in-vitro evaluation.

    Science.gov (United States)

    Baglar, Serdar; Erdem, Umit; Dogan, Mustafa; Turkoz, Mustafa

    2018-04-29

    In this in-vitro study, the effectiveness of experimental pure nano-hydroxyapatite (nHAP) and 1%, 2%, and 3% F¯ doped nano-HAp on dentine tubule occlusion was investigated. And also, the cytotoxicity of materials used in the experiment was evaluated. Nano-HAp types were synthesized by the precipitation method. Forty dentin specimens were randomly divided into five groups of; 1-no treatment (control), 2-specimens treated with 10% pure nano-HAp and 3, 4, 5 specimens treated with 1%, 2%, and 3% F - doped 10% nano-HAp, respectively. To evaluate the effectiveness of the materials used; pH, FTIR, and scanning electron microscopy evaluations were performed before and after degredation in simulated body fluid. To determine cytotoxicity of the materials, MTT assay was performed. Statistical evaluations were performed with F and t tests. All of the nano-HAp materials used in this study built up an effective covering layer on the dentin surfaces even with plugs in tubules. It was found that this layer had also a resistance to degradation. None of the evaluated nano-HAp types were have toxicity. Fluoride doping showed a positive effect on physical and chemical stability until a critical value of 1% F - . The all evaluated nano-HAp types may be effectively used in dentin hypersensitivity treatment. The formed nano-HAp layers were seem to resistant to hydrolic deletion. The pure and 1% F - doped nano-HAp showed the highest biocompatibility thus it was assessed that pure and 1% F - doped materials may be used as an active ingredient in dentin hypersensitivity agents. © 2018 Wiley Periodicals, Inc.

  15. Effectiveness of immediate bonding of etch-and-rinse adhesives to simplified ethanol-saturated dentin

    Directory of Open Access Journals (Sweden)

    Leandro Afonso Guimarães

    2012-04-01

    Full Text Available This study examined the immediate bond strength of etch-and-rinse adhesives to demineralized dentin saturated with either water or absolute ethanol. The research hypothesis was that there would be no difference in bond strength to dentin between water or ethanol wet-bonding techniques. The medium dentin of 20 third molars was exposed (n = 5. The dentin surface was then acid-etched, left moist and randomly assigned to be saturated via either water wet-bonding (WBT or absolute ethanol wet-bonding (EBT. The specimens were then treated with one of the following etch-and-rinse adhesive systems: a 3-step, water-based system (Adper Scotchbond Multipurpose, or SBMP or a 2-step, ethanol/water-based system (Adper Single Bond 2, or SB. Resin composite build-ups were then incrementally constructed. After water storage for 24 h at 37°C, the tensile strength of the specimens was tested in a universal testing machine (0.5 mm/min. Data were analyzed by two-way ANOVA and Tukey's test (a = 5%. The failure modes were verified using a stereomicroscope (40'. For both adhesives, no significant difference in bond strength was observed between WBT and EBT (p > 0.05. The highest bond strength was observed for SB, regardless of the bonding technique (p < 0.05. No significant interaction between adhesives and bonding techniques was noticed (p = 0.597. There was a predominance of adhesive failures for all tested groups. The EBT and WBT displayed similar immediate bond strength means for both adhesives. The SB adhesive exhibited higher means for all conditions tested. Further investigations are needed to evaluate long-term bonding to dentin mediated by commercial etch-and-rinse adhesives using the EBT approach.

  16. Microtensile bond strength of contemporary adhesives to primary enamel and dentin.

    Science.gov (United States)

    Marquezan, Marcela; da Silveira, Bruno Lopes; Burnett, Luiz Henrique; Rodrigues, Célia Regina Martins Delgado; Kramer, Paulo Floriani

    2008-01-01

    The purpose of this study was to assess bond strength of three self-etching and two total-etch adhesive systems bonded to primary tooth enamel and dentin. Forty extracted primary human molars were selected and abraded in order to create flat buccal enamel and occlusal dentin surfaces. Teeth were assigned to one of the adhesive systems: Adper Scotch Bond Multi Purpose, Adper Single Bond 2, Adper Prompt L-Pop, Clearfil SE Bond and AdheSE. Immediately to adhesive application, a composite resin (Filtek Z250) block was built up. After 3 months of water storage, each sample was sequentially sectioned in order to obtain sticks with a square cross-sectional area of about 0.72 mm2. The specimens were fixed lengthways to a microtensile device and tested using a universal testing machine with a 50-N load cell at a crosshead speed of 0.5 mm/min. Microtensile bond strength values were recorded in MPa and compared by Analysis of Variance and the post hoc Tukey test (a = 0.05). In enamel, Clearfil SE Bond presented the highest values, followed by Adper Single Bond 2, AdheSE and Adper Scotch Bond Multi Purpose, without significant difference. The highest values in dentin were obtained with Adper Scotch Bond Multi Purpose and all other adhesives did not present significant different values from that, except Adper Prompt L-Pop that achieved the lowest bond strength in both substrates. Adper Scotch Bond Multi Purpose and Adper Single Bond 2 presented significantly lower values in enamel than in dentin although all other adhesives presented similar results in both substrates. contemporary adhesive systems present similar behaviors when bonded to primary teeth, with the exception of the one-step self-etching system; and self-etching systems can achieve bond strength values as good in enamel as in dentin of primary teeth.

  17. Electron probe study of human and red deer cementum and root dentin

    Energy Technology Data Exchange (ETDEWEB)

    Toetdal, B. (Department of Physics, University of Trondheim, The Norwegian Institute of Technology); Hals, E. (Department of Cariology and Endodontics, Faculty of Odontology, University of Bergen, Norway)

    1985-01-01

    A topographical description of the concentration profiles of Ca, P, Mg, Zn, F, S, and K in human and red deer cementum and root dentin is given. The concentrations reported should be regarded as semiquantitative values. A downward slope of the Ca, P, and Mg profiles toward the pulpal cavity seemed largely to correspond with the secondary dentin. Marked elevations of the Zn profiles, modest elevations of the F profiles, and in a few instances of the S profiles, toward root surface and pulpal cavity were registered. In a couple of scans a slight elevation of the K profile toward the root surface was observed. A high degree of concordance in human and red deer teeth was ascertained.

  18. Estimation of Remnant Dentin Thickness under Proximal Caries Using Digital Bitewing Radiography: An In-Vitro Study

    Directory of Open Access Journals (Sweden)

    Masoomeh Afsa

    2015-12-01

    Full Text Available Objectives: In restorative dentistry, it is essential to estimate the amount of remnant tooth structure after caries removal to make the best treatment plan. The present study was aimed to determine whether there is a correlation between the real thickness of remnant dentin under carious lesion and the radiographical measurement from photostimulable phosphor plates (PSPs. Methods: a whole number of 68 unrestored permanent human molar and premolar teeth with 82 proximal carious surfaces were mounted in an artificial arch. Digital bitewing radiographs with PSPs were taken, carious lesions were removed and radiographic imaging was repeated. Teeth were sectioned mesiodistally in two parts and thickness of remnant tooth structure to pulp was measured. Measurements of remnant dentin under caries from radiographic images and teeth structures were compared. Result: The mean measurements of remnant dentin on primary radiographs were statistically different from the measurements on teeth structures. The mean thickness of remnant dentin on tooth structure was around 30% less than what measured on radiographic image. Conclusion: The real thickness of remnant dentin under caries is about 70% of its thickness measured on digital bitewing radiographs prepared by PSPs as image receptor.

  19. Dental Stem Cell Migration on Pulp Ceiling Cavities Filled with MTA, Dentin Chips, or Bio-Oss

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    Stefania Lymperi

    2015-01-01

    Full Text Available MTA, Bio-Oss, and dentin chips have been successfully used in endodontics. The aim of this study was to assess the adhesion and migration of dental stem cells on human pulp ceiling cavities filled with these endodontic materials in an experimental model, which mimics the clinical conditions of regenerative endodontics. Cavities were formed, by a homemade mold, on untouched third molars, filled with endodontic materials, and observed with electron microscopy. Cells were seeded on cavities’ surface and their morphology and number were analysed. The phenomenon of tropism was assessed in a migration assay. All three materials demonstrated appropriate microstructures for cell attachment. Cells grew on all reagents, but they showed a differential morphology. Moreover, variations were observed when comparing cells numbers on cavity’s filling versus the surrounding dentine disc. The highest number of cells was recorded on dentin chips whereas the opposite was true for Bio-Oss. This was confirmed in the migration assay where a statistically significant lower number of cells migrated towards Bio-Oss as compared to MTA and dentin chips. This study highlights that MTA and dentin chips have a greater potential compared to Bio-Oss regarding the attraction of dental stem cells and are good candidates for bioengineered pulp regeneration.

  20. The prevalence of secondary dentinal lesions in cheek teeth from horses with clinical signs of pulpitis compared to controls.

    Science.gov (United States)

    Casey, M B; Tremaine, W H

    2010-01-01

    With the advent of detailed oral examination in horses using dental mirrors and rigid endoscopy, secondary dentinal lesions are observed more frequently. More information regarding the association of secondary dentinal defects with apical dental disease would improve the sensitivity of oral examination as a diagnostic aid for pulpitis. To assess prevalence and severity of secondary dentinal defects observed on examination of occlusal surfaces of cheek teeth (CT) from horses showing clinical signs of pulpitis compared to asymptomatic controls. Records from all cases of equine CT exodontia at the University of Bristol over a 4 year period were examined. Case selection criteria included the presence of clinical signs of pulpitis, an intact extracted tooth and availability of a complete history and follow up. Cases where coronal fracture or periodontal pocketing featured were excluded. CT from cadavers with no history of dental disease served as normal controls. Triadan positions and eruption ages of control teeth were matched with those of teeth extracted from cases. CT from selected cases and control teeth were examined occlusally. Secondary dentinal defects were identified and graded. Prevalence of occlusal lesions in CT with pulpitis and controls was compared. From the records of 120 horses where exodontia was performed, 40 cases matched selection criteria. Twenty-three mandibular and 21 maxillary CT were extracted from cases. The controls consisted of 60 mandibular and 60 maxillary CT from 7 cadaver skulls. Secondary dentinal defects were significantly over-represented in CT extracted from cases of pulpitis (P pulpitis in equine CT.

  1. Cytotoxicity test of 40, 50 and 60% citric acid as dentin conditioner by using MTT assay on culture cell line

    Directory of Open Access Journals (Sweden)

    Christian Khoswanto

    2008-09-01

    Full Text Available Background: Open dentin is always covered by smear layer, therefore before restoration is performed, cavity or tooth which has been prepared should be clean from dirt. The researchers suggested that clean dentin surface would reach effective adhesion between resin and tooth structure, therefore dentin conditioner like citric acid was used to reach the condition. Even though citric acid is not strong acid but it can be very erosive to oral mucous. Several requirements should be fulfilled for dental product such as non toxic, non irritant, biocompatible and should not have negative effect against local, systemic or biological environment. Cytotoxicity test was apart of biomaterial evaluation and needed for standard screening. Purpose: This study was to know the cytotoxicity of 40, 50, 60% citric acid as dentin conditioner using MTT assay. Method: This study is an experimental research using the Post-Test Only Control Group Design. Six samples of each 40, 50 and 60% citric acid for citotoxicity test using MTT assay. The density of optic formazan indicated the number of living cells. All data were statistically analyzed by one way ANOVA. Result: The percentage of living cells in 40, 50 and 60% citric acid were 95.14%, 93.42% and 93.14%. Conclusion: Citric acid is non toxic and safe to be used as dentine conditioner.

  2. Clinical efficacy of toothpaste containing potassium citrate in treating dentin hypersensitivity

    Directory of Open Access Journals (Sweden)

    Shih-Ya Shen

    2009-12-01

    Conclusion: The prevalence of dentin hypersensitivity in this study was 38%. The use of desensitizing toothpaste containing potassium citrate with oral hygiene instruction can effectively reduce dentin hypersensitivity.

  3. Elemental content of enamel and dentin after bleaching of teeth (a comparative study between laser-induced breakdown spectroscopy and x-ray photoelectron spectroscopy)

    International Nuclear Information System (INIS)

    Imam, H.; Ahmed, Doaa; Eldakrouri, Ashraf

    2013-01-01

    The elemental content of the superficial and inner enamel as well as that of dentin was analyzed using laser-induced breakdown spectroscopy (LIBS) and x-ray photoelectron spectroscopy (XPS) of bleached and unbleached tooth specimens. It is thus clear from the spectral analysis using both the LIBS and XPS technique that elemental changes (though insignificant within the scopes of this study) of variable intensities do occur on the surface of the enamel and extend deeper to reach dentin. The results of the LIBS revealed a slight reduction in the calcium levels in the bleached compared to the control specimens in all the different bleaching groups and in both enamel and dentin. The good correlation found between the LIBS and XPS results demonstrates the possibility of LIBS technique for detection of minor loss in calcium and phosphorus in enamel and dentin.

  4. Elemental content of enamel and dentin after bleaching of teeth (a comparative study between laser-induced breakdown spectroscopy and x-ray photoelectron spectroscopy)

    Energy Technology Data Exchange (ETDEWEB)

    Imam, H. [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt); Ahmed, Doaa [Department of Restorative Sciences, Faculty of Dentistry, Alexandria University, Alexandria (Egypt); Eldakrouri, Ashraf [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt); Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh (Saudi Arabia)

    2013-06-21

    The elemental content of the superficial and inner enamel as well as that of dentin was analyzed using laser-induced breakdown spectroscopy (LIBS) and x-ray photoelectron spectroscopy (XPS) of bleached and unbleached tooth specimens. It is thus clear from the spectral analysis using both the LIBS and XPS technique that elemental changes (though insignificant within the scopes of this study) of variable intensities do occur on the surface of the enamel and extend deeper to reach dentin. The results of the LIBS revealed a slight reduction in the calcium levels in the bleached compared to the control specimens in all the different bleaching groups and in both enamel and dentin. The good correlation found between the LIBS and XPS results demonstrates the possibility of LIBS technique for detection of minor loss in calcium and phosphorus in enamel and dentin.

  5. Micromorphological features of the fine earth and skeletal fractions of soils of West Antarctica in the areas of Russian Antarctic stations

    Science.gov (United States)

    Abakumov, E. V.; Gagarina, E. I.; Sapega, V. F.; Vlasov, D. Yu.

    2013-12-01

    Micromorphological features of the fine earth and skeletal fractions of soils of West Antarctica forming under different conditions of pedogenesis have been studied in the areas of Russian Antarctic stations. The processes of mineral weathering and alteration of rock fragments are more pronounced in the Subantarctic soils with better developed humification and immobilization of iron compounds under conditions of surface overmoistening. The biogenic accumulative processes in the soils of King George Island result in the appearance of initial forms of humic plasma that have not been detected in the Antarctic soils in the areas of the Russkaya and Leningradskaya stations. Humus films on mineral grains are present in the soils of King George Island, and organic plasmic material is present in the ornithogenic soils under penguin guano on Lindsey Island. High-latitude Antarctic soils may contain surface concentrations of organic matter; rock fragments are covered by iron oxides and soluble salts. The formation of amorphous organic plasma takes place in the ornithogenic soils of Lindsey Island. The microprobe analysis indicates the presence of local concentrations of organic matter and pedogenic compounds not only on the surface of rock fragments but also in the fissures inside them. This analysis has also proved the translocation of guano-derived organic substances inside rock fragments through a system of fissures in the soils of Lindsey Island and the development of a network of pores inside rock fragments in the soils of King George Island.

  6. Effect of Er,Cr:YSGG laser on the microtensile bond strength of two different adhesives to the sound and caries-affected dentin.

    Science.gov (United States)

    Ergücü, Z; Celik, E U; Unlü, N; Türkün, M; Ozer, F

    2009-01-01

    This study examined the effect of Er,Cr:YSGG laser irradiation on the microtensile bond strength (microTBS) of a three-step etch-and-rinse and a two-step self-etch adhesive to sound and caries-affected dentin. Sixteen freshly extracted human molars with occlusal dentin caries were used. The caries lesion was removed by one of the following methods: conventional treatment with burs or Er,Cr:YSGG laser (Waterlase MD, Biolase). The adhesive systems (AdheSE, Ivoclar Vivadent and Scotchbond Multi Purpose, 3M ESPE) were applied to the entire tooth surface according to the manufacturers' instructions. Resin composites were applied to the adhesive-treated dentin surfaces and light-cured. Each tooth was sectioned into multiple beams with the "non-trimming" version of the microtensile test. The specimens were subjected to microtensile forces (BISCO Microtensile Tester, BISCO). The data was analyzed by three-way ANOVA and independent t-tests (p=0.05). Er,Cr:YSGG laser irradiation exhibited similar microTBS values compared to that of conventional bur treatment, regardless of the adhesive system and type of treated dentin. The self-etch system revealed lower microTBS values, both with conventional and laser treatment techniques, compared to the etch-and-rinse adhesive in sound and caries-affected dentin (padhesive systems to sound and caries-affected dentin.

  7. Effect of Different Protocols in Preconditioning With EDTA in Sclerotic Dentin and Enamel Before Universal Adhesives Applied in Self-etch Mode.

    Science.gov (United States)

    Martini, E C; Parreiras, S O; Gutierrez, M F; Loguercio, A D; Reis, A

    The aim of this study was to investigate the effect of different protocols of 17% ethylene diamine tetra-acetic acid (EDTA) conditioning on the etching pattern and immediate bond strength of universal adhesives to enamel and sclerotic dentin. Forty bovine teeth with sclerotic dentin and 20 human third molars were randomly divided into eight groups resulting from the combination of the main factors surface treatment (none, two-minute EDTA conditioning manual application, 30-second EDTA manual application, 30-second EDTA sonic application) and adhesives systems (Scotchbond Universal Adhesive [SBU] and Prime & Bond Elect [PBE]). Resin-dentin and enamel-dentin bond specimens were prepared and tested under the microtensile bond strength (μTBS) and microshear bond strength (μSBS) tests, respectively. The etching pattern produced on the unground enamel and the sclerotic dentin surfaces under the different protocols and adhesive systems was evaluated under scanning electron microscopy. For enamel, only the main factor adhesive was significant (padhesives in the self-etch mode on sclerotic dentin, mainly when applied for 30 seconds with the aid of a sonic device. EDTA pretreatment also improves the retentive etching pattern of enamel, but it does not result in higher enamel bond strength.

  8. Molecular energy dissipation in nanoscale networks of Dentin Matrix Protein 1 is strongly dependent on ion valence

    Science.gov (United States)

    Adams, J; Fantner, G E; Fisher, L W; Hansma, P K

    2008-01-01

    The fracture resistance of biomineralized tissues such as bone, dentin, and abalone is greatly enhanced through the nanoscale interactions of stiff inorganic mineral components with soft organic adhesive components. A proper understanding of the interactions that occur within the organic component, and between the organic and inorganic components, is therefore critical for a complete understanding of the mechanics of these tissues. In this paper, we use Atomic Force Microscope (AFM) force spectroscopy and dynamic force spectroscopy to explore the effect of ionic interactions within a nanoscale system consisting of networks of Dentin Matrix Protein 1 (DMP1) (a component of both bone and dentin organic matrix), a mica surface, and an AFM tip. We find that DMP1 is capable of dissipating large amounts of energy through an ion-mediated mechanism, and that the effectiveness increases with increasing ion valence. PMID:18843380

  9. Thin and thick layers of resin-based sealer cement bonded to root dentine compared: Adhesive behaviour.

    Science.gov (United States)

    Pane, Epita S; Palamara, Joseph E A; Messer, Harold H

    2015-12-01

    This study aims to evaluate tensile and shear bond strengths of one epoxy (AH) and two methacrylate resin-based sealers (EZ and RS) in thin and thick layers bonded to root dentine. An alignment device was prepared for accurate positioning of 20 root dentine cylinders in a predefined gap of 0.1 or 1 mm. Sealer was placed in the interface. Bond strength tests were conducted. Mode of failures and representative surfaces were evaluated. Data were analysed using anova and post-hoc tests, with P thick layer of sealer produced higher bond strength, except for the shear bond strength of EZ. Significant differences between thin and thick layers were found only in tensile bond strengths of AH and RS. Mixed type of failure was constantly found with all sealers. Bond strengths of thick layers of resin-based sealers to root dentine tended to be higher than with thin layers. © 2015 Australian Society of Endodontology.

  10. Molecular energy dissipation in nanoscale networks of dentin matrix protein 1 is strongly dependent on ion valence

    International Nuclear Information System (INIS)

    Adams, J; Fantner, G E; Hansma, P K; Fisher, L W

    2008-01-01

    The fracture resistance of biomineralized tissues such as bone, dentin, and abalone is greatly enhanced through the nanoscale interactions of stiff inorganic mineral components with soft organic adhesive components. A proper understanding of the interactions that occur within the organic component, and between the organic and inorganic components, is therefore critical for a complete understanding of the mechanics of these tissues. In this paper, we use atomic force microscope (AFM) force spectroscopy and dynamic force spectroscopy to explore the effect of ionic interactions within a nanoscale system consisting of networks of dentin matrix protein 1 (DMP1) (a component of both bone and dentin organic matrix), a mica surface and an AFM tip. We find that DMP1 is capable of dissipating large amounts of energy through an ion-mediated mechanism, and that the effectiveness increases with increasing ion valence

  11. Molecular energy dissipation in nanoscale networks of dentin matrix protein 1 is strongly dependent on ion valence

    Energy Technology Data Exchange (ETDEWEB)

    Adams, J; Fantner, G E; Hansma, P K [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106 (United States); Fisher, L W [Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, DHHS, Bethesda, MD 20892 (United States)], E-mail: adams@physics.ucsb.edu, E-mail: fantner@physics.ucsb.edu, E-mail: lfisher@dir.nidcr.nih.gov, E-mail: prasant@physics.ucsb.edu

    2008-09-24

    The fracture resistance of biomineralized tissues such as bone, dentin, and abalone is greatly enhanced through the nanoscale interactions of stiff inorganic mineral components with soft organic adhesive components. A proper understanding of the interactions that occur within the organic component, and between the organic and inorganic components, is therefore critical for a complete understanding of the mechanics of these tissues. In this paper, we use atomic force microscope (AFM) force spectroscopy and dynamic force spectroscopy to explore the effect of ionic interactions within a nanoscale system consisting of networks of dentin matrix protein 1 (DMP1) (a component of both bone and dentin organic matrix), a mica surface and an AFM tip. We find that DMP1 is capable of dissipating large amounts of energy through an ion-mediated mechanism, and that the effectiveness increases with increasing ion valence.

  12. Strontium effects on root dentin tubule occlusion and nanomechanical properties.

    Science.gov (United States)

    Saeki, Kuniko; Marshall, Grayson W; Gansky, Stuart A; Parkinson, Charles R; Marshall, Sally J

    2016-02-01

    Dentin hypersensitivity often is treated by promotion of dentin tubule occlusion. In this in vitro study we evaluated nanomechanical properties and degree of tubule occlusion conferred to sound and demineralized human root dentin following treatment with a 10% (w/w) strontium acetate solution and its relation to the treatment duration and delivery method. 24 human cervical root dentin disks (8 groups of 3) were polished through 0.25 μm. 12 disks were subjected to an acid challenge (1% citric acid, pH 3.8) for 2 min. The specimens were incubated in artificial saliva, treated by soaking or brushing with deionized (DI) water or a solution of 10% strontium acetate for 2 min twice a day for 28 days. The occlusion percent and nanomechanical properties were determined at the baseline, 5, 14 and 28 days. Cross-sectioned specimens were prepared to evaluate the depth affected by strontium acetate / dentin interaction by SEM. Statistical analysis was performed using linear mixed effects models. A 10% strontium acetate treatment over 5-28 days significantly increased tubule occlusion for normal root dentin and to a lesser extent for demineralized dentin and increased the AFM based nanomechanical properties of demineralized dentin. Brushing was more effective than soaking in recovery of properties of demineralized dentin when treated with strontium. No difference in tubuleocclusion was found between the two delivery methods. Strontium acetate itself proved to have the ability to occlude dentin tubules and result in small changes in the mechanical properties of dentin. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  13. Six-month storage-time evaluation of one-bottle adhesive systems to dentin.

    Science.gov (United States)

    Giannini, Marcelo; Seixas, Carla Alessandra Marcelino; Reis, Andre Figueiredo; Pimenta, Luiz André Freire

    2003-01-01

    The goal of this study was to evaluate the 1-week, 3-month, and 6-month performance of eight commercially available one-bottle adhesive systems to dentin. Lingual and buccal surfaces from human third molars were ground wet on 600-grit SiC paper to obtain a flat dentinal surface. The specimens were randomly divided into 24 groups (n = 10), which were established to measure the shear bond strengths of Bond-1 (B1), ONE-STEP (OS), OptiBond SOLO (OP), Prime & Bond 2.1 (PB), Single Bond (SB), STAE (ST), Syntac Sprint (SS), and Tenure Quick (TQ) after 1-week, 3-month, and 6-month water storage at 37 degrees C. One-bottle adhesives were applied according to manufacturers' instructions and Z100 composite cylinders were applied on the bonded dentinal surfaces. The 3-month water-storage groups were thermocycled for 1500 cycles at 5 degrees C and 55 degrees C and 6-month groups for 3000 cycles. After storage periods, specimens were tested in shear in a universal testing machine (0.5 mm/min). were statistically analyzed by analysis of variance and Tukey test. Results: The changes in shear bond strengths were not uniform over time. Over the test period, OS, PB, SB, and SS exhibited bond strength stability, however, SS presented low bond strengths on all tested periods. A significant decrease in bond strength was observed for B1, OP, ST, and TQ after the 6-month storage period.

  14. Bond strength to dentin with artificial carious lesions: influence of caries detecting dye.

    Science.gov (United States)

    Palma, R G; Turbino, M L; Matson, E; Powers, J M

    1998-06-01

    To evaluate the influence of dyes for caries detection on tensile bond strength of adhesive materials to artificial carious dentin. Buccal and lingual enamel of human molars were removed leaving intact dentin surfaces. The entire surface of each specimen was covered with nail varnish, keeping a window area of 4 x 4 mm. Artificial carious lesions were induced with acidified gel. Three dyes (0.5% basic fuchsin; Caries Finder and Cari-D-Tect) were used according to manufacturers' recommendations. Specimens were etched with 35% phosphoric acid for 20 s, washed and dried, leaving a wet dentin surface. The adhesive system (Prime & Bond 2.0) was applied in two layers and light-cured. Restorative materials (TPH Spectrum, Dyract, Advance) were bonded using a 3-mm diameter inverted-cone mold. Control groups were made without dye. Eight samples were tested for each group. After 24 hrs of storage in distilled water, the samples were debonded using a testing machine at 0.5 mm/min crosshead speed. ANOVA and Tukey-Kramer test showed that TPH Spectrum (0.73 MPa) and Dyract (0.74 MPa) had similar bond strengths, and both were higher than Advance (0.0 MPa), which was statistically different (P strength for any tested materials.

  15. Do leaf surface characteristics affect Agrobacterium infection in tea

    Indian Academy of Sciences (India)

    The host range specificity of Agrobacterium with five tea cultivars and an unrelated species (Artemisia parviflora) having extreme surface characteristics was evaluated in the present study. The degree of Agrobacterium infection in the five cultivars of tea was affected by leaf wetness, micro-morphology and surface chemistry.

  16. Comparison of the shear bond strength of self-adhesive resin cements to enamel and dentin with different protocol of application.

    Science.gov (United States)

    Moghaddas, Mohammad Javad; Hossainipour, Zahra; Majidinia, Sara; Ojrati, Najmeh

    2017-08-01

    The aim of the present study was to determine the shear bond strength of self-adhesive resin cements to enamel and dentin with and without surface treatments, and compare them with conventional resin cement as the control group. In this experimental study, buccal and lingual surface of the thirty sound human premolars were polished in order to obtain a flat surface of enamel (E) in buccal, and dentin (D) in lingual. Sixty feldspathic ceramic blocks (2×3×3 mm) were prepared and randomly divided into six groups (n=10). Each block was cemented to the prepared surface (30 enamel and 30 dentin surface) according to different protocol: E1 and D1; RelyX ARC as control group, E2, D2; RelyX Unicem, E3, D3; acid etching +RelyX Unicem. The specimens were termocycled and subjected to shear forces by a universal testing machine at a cross head speed of 0.5 mm/min. The mode of fracture were evaluated by stereomicroscope. Data were analyzed with descriptive statistical methods using SPSS version 15. One-way ANOVA, and post hoc Tukey tests were used to compare bond strengths between the groups with different adhesives at α=0.05. Statistical analysis showed no significant differences within the enamel subgroups, but there were significant differences within the dentinal subgroups, and statistically significant differences were found between the groups D1and D3 (p=0.02). Comparison between similar enamel and dentinal subgroups showed that there was a significant difference just between the subgroups E3 and D3 (p=0.01). Elective etching of enamel did not lead to significant increase in the shear bond strength of RelyX Unicem in comparison to RelyX ARC. On the other hand, elective etching of dentin reduces the bond strength of RelyX Unicem with the dentin.

  17. Shear bond strength of one-step self-etch adhesives to dentin: Evaluation of NaOCl pretreatment.

    Science.gov (United States)

    Colombo, Marco; Beltrami, Riccardo; Chiesa, Marco; Poggio, Claudio; Scribante, Andrea

    2018-02-01

    The aim of this study was to evaluate the influence of dentin pretreatment with NaOCl on shear bond strength of four one-step self-etch adhesives with different pH values. Bovine permanent incisors were used. Four one-step self-etch adhesives were tested: Adper™ Easy Bond, Futurabond NR, G-aenial Bond, Clearfil S3 Bond. One two-step self-etch adhesive (Clearfil SE Bond) was used as control. Group 1- no pretreatment; group 2- pretratment with 5,25 % NaOCl; group 3- pretreatment with 37 % H3PO4 etching and 5,25 % NaOCl. A hybrid composite resin was inserted into the dentin surface. The specimens were tested in a universal testing machine. The examiners evaluated the fractured surfaces in optical microscope to determine failure modes, quantified with adhesive remnant index (ARI). Dentin pretreatment variably influenced bond strength values of the different adhesive systems. When no dentin pretreatment was applied, no significant differences were found ( P >.05) among four adhesives tested. No significant differences were recorded when comparing NaOCl pretreatment with H3PO4 + NaOCl pretreatment for all adhesive tested ( P >.05) except Clearfil S3 Bond that showed higher shear bond strength values when H3PO4 was applied. Frequencies of ARI scores were calculated. The influence of dentin pretreatment with NaOCl depends on the composition of each adhesive system used. There was no difference in bond strength values among self-etch adhesives with different pH values. Key words: Dentin, pretreatment, self-etch adhesives.

  18. Effect of Storage Time on Bond Strength and Nanoleakage Expression of Universal Adhesives Bonded to Dentin and Etched Enamel.

    Science.gov (United States)

    Makishi, P; André, C B; Ayres, Apa; Martins, A L; Giannini, M

    2016-01-01

    To investigate bond strength and nanoleakage expression of universal adhesives (UA) bonded to dentin and etched enamel. Extracted human third molars were sectioned and ground to obtain flat surfaces of dentin (n = 36) and enamel (n = 48). Dentin and etched enamel surfaces were bonded with one of two UAs, All-Bond Universal (ABU) or Scotchbond Universal (SBU); or a two-step self-etching adhesive, Clearfil SE Bond (CSEB). A hydrophobic bonding resin, Adper Scotchbond Multi-Purpose Bond (ASMP Bond) was applied only on etched enamel. Following each bonding procedure, resin composite blocks were built up incrementally. The specimens were sectioned and subjected to microtensile bond strength (MTBS) testing after 24 hours or one year water storage, or immersed into ammoniacal silver nitrate solution after aging with 10,000 thermocycles and observed using scanning electron microscopy. The percentage distribution of silver particles at the adhesive/tooth interface was calculated using digital image-analysis software. The MTBS (CSEB = SBU > ABU, for dentin; and CSEB > ABU = SBU = ASMP Bond, for etched enamel) differed significantly between the adhesives after 24 hours. After one year, MTBS values were reduced significantly within the same adhesive for both substrates (analysis of variance, Bonferroni post hoc, padhesives for etched enamel. Silver particles could be detected within the adhesive/dentin interface of all specimens tested. Kruskal-Wallis mean ranks for nanoleakage in ABU, SBU, and CSEB were 16.9, 18.5 and 11, respectively (p>0.05). In the short term, MTBS values were material and dental-substrate dependent. After aging, a decrease in bonding effectiveness was observed in all materials, with nanoleakage at the adhesive/dentin interface. The bonding of the UAs was equal or inferior to that of the conventional restorative systems when applied to either substrate and after either storage period.

  19. Shear bond strength of bulk-fill and nano-restorative materials to dentin.

    Science.gov (United States)

    Colak, Hakan; Ercan, Ertugrul; Hamidi, Mehmet Mustafa

    2016-01-01

    Bulk-fill composite materials are being developed for preparation depths of up to 4 mm in an effort to simplify and improve the placement of direct composite posterior restorations. The aim of our study was to compare shear-bond strength of bulk-fill and conventional posterior composite resins. In this study, 60 caries free extracted human molars were used and sectioned parallel to occlusal surface to expose midcoronal dentin. The specimens were randomly divided into four groups. Total-etch dentine bonding system (Adper Scotchbond 1XT, 3M ESPE) was applied to dentin surface in all the groups to reduce variability in results. Then, dentine surfaces covered by following materials. Group I: SonicFill Bulk-Fill, Group II: Tetric EvoCeram (TBF), Group III: Herculite XRV Ultra, and Group IV: TBF Bulk-Fill, 2 mm × 3 mm cylindrical restorations were prepared by using application apparatus. Shear bond testing was measured by using a universal testing machine. Kruskal-Wallis and Mann-Whitney U-tests were performed to evaluate the data. The highest value was observed in Group III (14.42 ± 4.34) and the lowest value was observed in Group IV (11.16 ± 2.76) and there is a statistically significant difference between these groups (P = 0.046). However, there is no statistically significant difference between the values of other groups. In this study, Group III was showed higher strength values. There is a need for future studies about long-term bond strength and clinical success of these adhesive and bulk-fill systems.

  20. Shear bond strength of three adhesive systems to enamel and dentin of permanent teeth

    Directory of Open Access Journals (Sweden)

    Niloofar Shadman

    2012-01-01

    Full Text Available Background and Aims: The purpose of this experimental study was to investigate the shear bond strength of three new adhesive systems to enamel and dentin of permanent human teeth using three new etch and rinse and self-etch adhesive systems.Materials and Methods: Sixty intact caries-free third molars were selected and randomly divided into 6 groups. Flat buccal and lingual enamel and dentin surfaces were prepared and mounted in the acrylic resin perpendicular to the plan of the horizon. Adhesives used in this study were Tetric N-Bond, AdheSE and AdheSE-One F (Ivoclar/Vivadent, Schaan, Liechtenstein. The adhesives were applied on the surfaces and cured with quartz tungsten halogen curing unit (600 mW/cm2 intensity for 20 s. After attaching composite to the surfaces and thermocycling (500 cycles, 5-55ºC, shear bond strength was measured using a universal testing machine at a crosshead speed of 0.5 mm/min. The failure modes were examined under a stereomicroscope. The data were statistically analyzed using T-test, one-way ANOVA, Tukey and Fisher's exact tests.Results: In enamel, Tetric N-Bond (28.57±4.58 MPa and AdheSE (21.97±7.6 MPa had significantly higher bond strength than AdheSE-One F (7.16±2.09 MPa (P0.05.Conclusion: Shear bond strength to dentin in Tetric N-Bond (etch and rinse system( was higher than self-etch adhesives (AdheSE and AdheSE-One F. The bond strength to enamel and dentin in two-step self-etch (AdheSE was higher than one-step self-etch (AdheSE-One F.

  1. Effect of Different Saliva Decontamination Procedures on Bond Strength to Dentin in Single Bottle Systems

    Directory of Open Access Journals (Sweden)

    M. Ghavam

    2004-09-01

    Full Text Available Statement of Problem: Following the increasing use of composites in restoring anterior and posterior teeth, problems due to its technique sensitivity have become a major concern.One of these problems is the possibility of contamination of dentin with saliva, blood and/or gingival fluid in different stages of bonding procedure, even with application of different methods of isolation. However, by introduction of Single-bottle dentin adhesives,the contamination possibility reduced to two stages. Scientific documents show that saliva contamination reduces bond strength of composites to dentin. Application of simple and efficient methods for reducing or eliminating saliva contamination enables clinicians to carry out dental treatment without any concern about deterioration of clinical longevity of restoration.Purpose: This study was designed to compare the effect of different decontamination methods on the shear bond strength of composite to dentin using a “Single-bottle” adhesive.Materials and Methods: Seventy-two extracted sound human molars and premolars were selected. Enamel of buccal surface was ground flat to expose dentin. The teeth were divided into 9 groups of 8 each. In control group (1 the adhesive “Excite” was used according tothe manufacturer, without any contamination. Conditioned and saliva contaminated dentin was (2 rinsed and blot dried, (3 rinsed, dried and re-etched. In groups 4, 5, 6 uncured adhesive was saliva contaminated and then: (4 only blot dried (5 rinsed, blot dried with adhesive reapplication and (6 resurfaced with bur, rinsed, dried and followed by repeating the whole process. In groups 7, 8, 9 cured adhesive was contaminated with saliva and then:(7 rinsed and dried (8 rinsed, blot dried with adhesive reapplication (9 same as group (6.Then “Tetric Ceram” composite cylinders were bonded to dentin surfaces. Samples were thermo cycled in 5°C and 55°C water, 30 seconds in each bath with a dowel time of 10

  2. How were the ditches filled? Sedimentological and micromorphological classification of formation processes within graben-like archaeological objects

    Czech Academy of Sciences Publication Activity Database

    Lisá, Lenka; Komoróczy, Balázs; Vlach, Marek; Válek, M.; Bajer, A.; Kovárník, J.; Rajtár, J.; Hüssen, C.-M.; Šumberová, Radka

    2015-01-01

    Roč. 370, 3 June (2015), s. 66-76 ISSN 1040-6182 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M300011201 Program:M Institutional support: RVO:67985831 ; RVO:68081758 ; RVO:67985912 Keywords : formation processes * micromorphology * Neolithic rondel structures * Roman ditch * sedimentology * V-shaped ditch Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 2.067, year: 2015

  3. Polymerization contraction stress in dentin adhesives bonded to dentin and enamel

    NARCIS (Netherlands)

    Hashimoto, M.; de Gee, A.J.; Feilzer, A.J.

    2008-01-01

    Objective In a previous study on of polymerization contraction stress determinations of adhesives bonded to dentin a continuous decline of stress was observed after the adhesives had been light-cured. The decline was ascribed to stress relief caused by diffusion into the adhesive layer of water

  4. An unusual oral habit presenting as Dentin Hypersensitivity | Afolabi ...

    African Journals Online (AJOL)

    We present the case of a 30-year-old man with an unusual oral habit- office pin chewing and filing of the front tooth which resulted in dentine hypersensitivity. Clinical relevance: The role of daily oral habits and techniques of cessation were suggested in the management of dentine hypersensitivity. Keywords: Unusual oral ...

  5. Staining of dentin from amalgam corrosion is induced by demineralization

    NARCIS (Netherlands)

    Scholtanus, J.D.; van der Hoorn, W.; Özcan, M.; Huysmans, M.C.D.N.J.M.; Roeters, J.F.M.; Kleverlaan, C.J.; Feilzer, A.J.

    2013-01-01

    PURPOSE: To evaluate the effect of artificial demineralization upon color change of dentin in contact with dental amalgam. METHODS: Sound human molars (n = 34) were embedded in resin and coronal enamel was removed. Dentin was exposed to artificial caries gel (pH 5.5) at 37 degrees C for 12 weeks (n

  6. Staining of dentin from amalgam corrosion is induced by demineralization

    NARCIS (Netherlands)

    Scholtanus, Johannes D.; van der Hoorn, Wietske; Huysmans, Marie-Charlotte D. N. J. M.; Roeters, Joost F. M.; Kleverlaan, Cornelis J.; Feilzer, Albert J.; Ozcan, Mutlu

    Purpose: To evaluate the effect of artificial demineralization upon color change of dentin in contact with dental amalgam. Methods: Sound human molars (n= 34) were embedded in resin and coronal enamel was removed. Dentin was exposed to artificial caries gel (pH 5.5) at 37 degrees C for 12 weeks (n=

  7. Effects of simulated acid rain on leaf anatomy and micromorphology of Genipa americana L. (Rubiaceae

    Directory of Open Access Journals (Sweden)

    Bruno Francisco Sant'Anna-Santos

    2006-03-01

    Full Text Available Experiments were conducted in order to characterize the injuries on leaf structure and micromorphology of G. americana and evaluate the degree of susceptibility of this species to simulated acid rain. Plants were exposed to acid rain (pH 3.0 for ten consecutive days. Control plants were submitted only to distilled water (pH 6.0. Leaf tissue was sampled and fixed for light and scanning electron microscopy. Necrotic interveinal spots on the leaf blade occurred. Epidermis and mesophyll cells collapse, hypertrophy of spongy parenchyma cells, accumulation of phenolic compounds and starch grains were observed in leaves exposed to acid rain. The micromorphological analysis showed, in necrotic areas, plasmolized guard cells and cuticle rupture. Epidermal and mesophyll cells alterations occurred before symptoms were visualized in the leaves. These results showed the importance of anatomical data for precocious diagnosis injury and to determine the sensitivity of G. americana to acid rain.Experimentos foram conduzidos para avaliar o grau de susceptibilidade e determinar as injúrias causadas pela chuva ácida simulada na anatomia e micromorfologia foliar de Genipa americana. Plantas foram expostas à chuva com pH 3,0 durante 10 dias consecutivos. No tratamento controle utilizou-se apenas água destilada (pH 6,0. Amostras foliares foram coletadas e fixadas para microscopia de luz e eletrônica de varredura. Foram observados nas folhas expostas à chuva ácida: necroses pontuais intervenais, colapso das células do mesofilo e da epiderme; hipertrofia do parênquima lacunoso e acúmulo de compostos fenólicos e grãos de amido. A análise micromorfológica evidenciou, nas áreas necrosadas, plasmólise das células-guarda e ruptura da cutícula e da crista estomática. Alterações anatômicas ocorreram antes que sintomas visuais fossem observados nas folhas. Estes resultados comprovam a importância de dados anatômicos na diagnose precoce da injúria e na

  8. The shear bond strength of self-adhesive resin cements to dentin and enamel: an in vitro study.

    Science.gov (United States)

    Rodrigues, Raphaela F; Ramos, Carla M; Francisconi, Paulo A S; Borges, Ana Flávia S

    2015-03-01

    Clinicians continue to search for ways to simplify bonding procedures without compromising clinical efficacy. The purpose of this study was to evaluate the shear strength of self-adhesive cements RelyX U100 and RelyX U200, and conventional resin cement RelyX ARC to enamel and dentin after different surface treatments. The crowns of 120 bovine incisor teeth were separated from the roots and embedded in epoxy resin in polyvinyl chloride tubes. In each tooth, the area to be cemented was delimited with central holed adhesive tape. The teeth were distributed into 12 groups (n=10) according to the substrate; etched or not with 37% phosphoric acid; and cement type of enamel-U100, enamel-phosphoric acid-U100, enamel-U200, enamel-phosphoric acid-U200, enamel-ARC, enamel-phosphoric acid-ARC, dentin-U100, dentin-phosphoric acid-U100, dentin-U200, dentin-phosphoric acid-U200, dentin-ARC, and dentin-phosphoric acid-ARC. After 7 days of storage in artificial saliva, shear strength tests were performed by using a universal testing machine (0.5 mm/min). The data were analyzed with 3-way ANOVA and the Tukey test (α=.05). Fracture analysis was performed with a light microscope. Two specimens from each group were analyzed with a scanning electron microscope. In enamel, ARC (9.96 MPa) had higher shear strength (P=.038) than U100 (5.14 MPa); however, after surface etching, U100 (17.81 MPa) and U200 (17.52 MPa) had higher shear strength (Padhesive type. U200 self-adhesive cement had similar bond strength to the ARC in enamel, but the combination with phosphoric acid had the best bond strength. For dentin, self-adhesive resin cements are equally effective alternatives to conventional resin cement. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  9. Topical application of bFGF on acid-conditioned and non-conditioned dentin: effect on cell proliferation and gene expression in cells relevant for periodontal regeneration

    Directory of Open Access Journals (Sweden)

    Fernanda Regina Godoy Rocha

    Full Text Available Abstract Periodontal regeneration is still a challenge in terms of predictability and magnitude of effect. In this study we assess the biological effects of combining chemical root conditioning and biological mediators on three relevant cell types for periodontal regeneration. Material and Methods: Bovine dentin slices were conditioned with 25% citric acid followed by topical application of basic fibroblast growth factor (bFGF, 10 and 50 ng. We used ELISA to assess the dynamics of bFGF release from the dentin surface and RT-qPCR to study the expression of Runx2, Col1a1, Bglap and fibronectin by periodontal ligament (PDL fibroblasts, cementoblasts and bone marrow stromal cells (BMSC grown onto these dentin slices. We also assessed the effects of topical application of bFGF on cell proliferation by quantification of genomic DNA. Results: Acid conditioning significantly increased the release of bFGF from dentin slices. Overall, bFGF application significantly (p<0.05 increased cell proliferation, except for BMSC grown on non-conditioned dentin slices. Dentin substrate discretely increased expression of Col1a1 in all cell types. Expression of Runx2, Col1a1 and Fn was either unaffected or inhibited by bFGF application in all cell types. We could not detect expression of the target genes on BMSC grown onto conditioned dentin. Conclusion: Acid conditioning of dentin improves the release of topically-applied bFGF. Topical application of bFGF had a stimulatory effect on proliferation of PDL fibroblasts, cementoblasts and BMSC, but did not affect expression of Runx2, Col1a1, Bglap and fibronectin by these cells.

  10. EFFECT OF AN ADDITIONAL HYDROPHILIC VERSUS HYDROPHOBIC COAT ON THE QUALITY OF DENTINAL SEALING PROVIDED BY TWO-STEP ETCH-AND-RINSE ADHESIVES

    Science.gov (United States)

    Silva, Safira Marques de Andrade; Carrilho, Marcela Rocha de Oliveira; Marquezini, Luiz; Garcia, Fernanda Cristina Pimentel; Manso, Adriana Pigozzo; Alves, Marcelo Corrêa; de Carvalho, Ricardo Marins

    2009-01-01

    Objective: To test the hypothesis that the quality of the dentinal sealing provided by two-step etch-and-rinse adhesives cannot be altered by the addition of an extra layer of the respective adhesive or the application of a more hydrophobic, non-solvated resin. Material and Methods: full-crown preparations were acid-etched with phosphoric acid for 15 s and bonded with Adper Single Bond (3M ESPE), Excite DSC (Ivoclar/Vivadent) or Prime & Bond NT (Dentsply). The adhesives were used according to the manufacturers' instructions (control groups) or after application to dentin they were a) covered with an extra coat of each respective system or b) coated with a non-solvated bonding agent (Adper Scotchbond Multi-Purpose Adhesive, 3M ESPE). Fluid flow rate was measured before and after dentin surfaces were acid-etched and bonded with adhesives. Results: None of the adhesives or experimental treatments was capable to block completely the fluid transudation across the treated dentin. Application of an extra coat of the adhesive did not reduce the fluid flow rate of adhesive-bonded dentin (p>0.05). Conversely, the application of a more hydrophobic non-solvated resin resulted in significant reductions in the fluid flow rate (padhesives. Conclusions: The quality of the dentinal sealing provided by etch-and-rinse adhesives can be significantly improved by the application of a more hydrophobic, non-solvated bonding agent. PMID:19466248

  11. Effect of functional monomers in all-in-one adhesive systems on formation of enamel/dentin acid-base resistant zone.

    Science.gov (United States)

    Nikaido, Toru; Ichikawa, Chiaki; Li, Na; Takagaki, Tomohiro; Sadr, Alireza; Yoshida, Yasuhiro; Suzuki, Kazuomi; Tagami, Junji

    2011-01-01

    This study aimed at evaluating the effect of functional monomers in all-in-one adhesive systems on formation of acid-base resistant zone (ABRZ) in enamel and dentin. Experimental adhesive systems containing one of three functional monomers; MDP, 3D-SR and 4-META were applied to enamel or dentin surface and light-cured. A universal resin composite was then placed. The specimens were subjected to a demineralizing solution (pH 4.5) and 5% NaClO for acid-base challenge and then observed by SEM. The ABRZ was clearly observed in both enamel and dentin interfaces. However, enamel ABRZ was thinner than dentin ABRZ in all adhesives. Morphology of the ABRZ was different between enamel and dentin, and also among the adhesives. Funnel-shaped erosion was observed only in the enamel specimen with the 4-META adhesive. The formation of enamel/dentin ABRZ was confirmed in all adhesives, but the morphology was influenced by the functional monomers.

  12. Adhesive interfaces of enamel and dentin prepared by air-abrasion at different distances

    International Nuclear Information System (INIS)

    Chinelatti, Michelle Alexandra; Andreolli do Amaral, Thais Helena; Borsatto, Maria Cristina; Palma-Dibb, Regina Guenka; Corona, Silmara Aparecida Milori

    2007-01-01

    The purpose of this study was to analyse, by scanning electron microscopy (SEM), the morphology of enamel and dentin/adhesive interfaces in cavities prepared by air-abrasion at different working distances. Thirty sound third human molars were selected and, on both their buccal and lingual surfaces, class V cavities were prepared by air-abrasion, at 2-, 4-, 6-, 8- and 10-mm working distances, or high-speed bur (control group). After preparation, all cavities were etched with 35% phosphoric acid gel and restored with Single Bond/Filtek Z-250. Buccal and lingual surfaces were separated and restorations sectioned in a buccolingual direction, providing two sections of each cavity, which were analysed by scanning electron microscopy. It was observed that the distances of 6 and 8 mm promoted more homogeneous dentin/adhesive interfaces, with tags formation, and more uniform for enamel, which were similar to the control group. It may be concluded that the air-abrasion working distance can influence the morphology of enamel and dentin/adhesive interfaces, and the intermediate distances provided better adhesive interfaces

  13. Ultrastructural analysis of root canal dentine irradiated with 980-nm diode laser energy at different parameters.

    Science.gov (United States)

    Marchesan, Melissa Andréia; Brugnera-Junior, Aldo; Souza-Gabriel, Aline Evangelista; Correa-Silva, Silvio Rocha; Sousa-Neto, Manoel D

    2008-06-01

    The purpose of this in vitro study was to investigate using the scanning electron microscope (SEM) the ultrastructural morphological changes of the radicular dentine surface after irradiation with 980-nm diode laser energy at different parameters and angles of incidence. There have been limited reports on the effects of diode laser irradiation at 980 nm on radicular dentin morphology. Seventy-two maxillary canines were sectioned and roots were biomechanically prepared using K3 rotary instruments. The teeth were irrigated with 2 mL of distilled water between files and final irrigation was performed with 10 mL of distilled water. The teeth were then randomly divided into five groups (n = 8 each) according to their diode laser parameters: Group 1: no irradiation (control); group 2: 1.5 W/continuous wave (CW) emission (the manufacturer's parameters); group 3: 1.5 W/100 Hz; group 4: 3 W/CW; and group 5: 3 W/100 Hz. Laser energy was applied with helicoid movements (parallel to the canal walls) for 20 sec. Eight additional teeth for each group were endodontically prepared and split longitudinally and irradiation was applied perpendicularly to the root surface. Statistical analysis showed no difference between the root canal thirds irradiated with the 980-nm diode laser, and similar results between the parameters 1.5 W/CW and 3 W/100 Hz (p > 0.05). When considering different output powers and delivery modes our results showed that changes varied from smear layer removal to dentine fusion.

  14. Selective ablation of dental enamel and dentin using femtosecond laser pulses

    International Nuclear Information System (INIS)

    Lizarelli, R F Z; Costa, M M; Carvalho-Filho, E; Bagnato, V S; Nunes, F D

    2008-01-01

    The study of the interaction of intense laser light with matter, as well as transient response of atoms and molecules is very appropriated because of the laser energy concentration in a femtosecond optical pulses. The fundamental problem to be solved is to find tools and techniques which allow us to observe and manipulate on a femtosecond time scale the photonics events on and into the matter. Six third human extracted molars were exposed to a femtosecond Ti:Sapphire Q-switched and mode locked laser (Libra-S, Coherent, Palo Alto, CA, USA), emitting pulses with 70 fs width, radiation wavelength of 801 nm, at a constant pulse repetition rate of 1 KHz. The laser was operated at different power levels (70 to 400 mW) with constant exposition time of 10 seconds, at focused and defocused mode. Enamel and dentin surfaces were evaluated concerned ablation rate and morphological aspects under scanning electron microscopic. The results in this present experiment suggest that at the focused mode and under higher average power, enamel tissues present microcavities with higher depth and very precise edges, but, while dentin shows a larger melt-flushing, lower depth and melting and solidification aspect. In conclusion, it is possible to choose hard or soft ablation, under lower and higher average power, respectively, revealing different aspects of dental enamel and dentin, depending on the average power, fluence and distance from the focal point of the ultra-short pulse laser on the tooth surface

  15. Influence of different etching modes on bond strength and fatigue strength to dentin using universal adhesive systems.

    Science.gov (United States)

    Takamizawa, Toshiki; Barkmeier, Wayne W; Tsujimoto, Akimasa; Berry, Thomas P; Watanabe, Hedehiko; Erickson, Robert L; Latta, Mark A; Miyazaki, Masashi

    2016-02-01

    The purpose of this study was to determine the dentin bonding ability of three new universal adhesive systems under different etching modes using fatigue testing. Prime & Bond elect [PE] (DENTSPLY Caulk), Scotchbond Universal [SU] (3M ESPE), and All Bond Universal [AU] (Bisco) were used in this study. A conventional single-step self-etch adhesive, Clearfil Bond SE ONE [CS] (Kuraray Noritake Dental) was also included as a control. Shear bond strengths (SBS) and shear fatigue strength (SFS) to human dentin were obtained in the total-etch mode and self-etch modes. For each test condition, 15 specimens were prepared for the SBS and 30 specimens for SFS. SEM was used to examine representative de-bonded specimens, treated dentin surfaces and the resin/dentin interface for each test condition. Among the universal adhesives, PE in total-etch mode showed significantly higher SBS and SFS values than in self-etch mode. SU and AU did not show any significant difference in SBS and SFS between the total-etch mode and self-etch mode. However, the single-step self-etch adhesive CS showed significantly lower SBS and SFS values in the etch-and-rinse mode when compared to the self-etch mode. Examining the ratio of SFS/SBS, for PE and AU, the etch-and-rinse mode groups showed higher ratios than the self-etch mode groups. The influence of different etching modes on dentin bond quality of universal adhesives was dependent on the adhesive material. However, for the universal adhesives, using the total-etch mode did not have a negative impact on dentin bond quality. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  16. Effect of Re-Application of Microbrush on Micro Tensile Bond Strength of an Adhesive to Dentin

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    Seied Majid Mosavi Nasab

    2013-02-01

    Full Text Available Background and Aims: Re-application of microbrush may affect the micro tensile bond strength of adhesives to dentin. The aim of this study was to evaluate the effect of re-application of microbrushes on the micro tensile bond strength of an adhesive to dentin.Materials and Methods: Thirty freshly extracted molars teeth were collected and enamel of occlusal surface were removed to expose superficial dentin. Then superficial dentin was etched, washed and partially air dried.According to the times of application of microbrush, teeth were divided into two test groups. In group 1, newmicrobrushs were used, but in group 2, the ones that were already used for twice were included. Ambar dentin bonding agent (FGM/Brazil was applied to the etched dentin with microbrushes according to the manufacturer’s instructions. Then the crown of teeth was built up with LLiss (FGM/Brazil composite resin. The teeth were sectioned in buccolingual direction to obtain 1mm slabs. Then 50 hourglass- shape samples were made from 30 teeth (25 Specimens per group. The microtensile bond strength of the specimens was tested using MTD500 (SD Mechatronik, Germany. The data were statistically analyzed by T-test.Results: The mean values for the microtensile bond strength were 30.49±7.18 and 23.61±9.06 MPa±SD for the first and second groups, respectively. There was significant difference between the groups (P=0.005.Conclusion: Microbrushes should not be used for more than one cavity preparation.

  17. Changes in dimensions and weight of human dentine after different drying procedures and during subsequent rehydration

    NARCIS (Netherlands)

    Van der Graaf, E R; Ten Bosch, J J

    Shrinkage of dentine and the decrease in its weight after drying were measured. Three drying procedures were used, freeze-drying and drying in nitrogen at 60 and 100 degrees C. The dentine was subsequently rehydrated while measuring its dimensions. Rehydrated dentine was weighed. Dentine weight

  18. Effect of Adhesive Cementation Strategies on the Bonding of Y-TZP to Human Dentin.

    Science.gov (United States)

    Alves, Mll; Campos, F; Bergoli, C D; Bottino, M A; Özcan, M; Souza, Roa

    2016-01-01

    This study evaluated the effects of different adhesive strategies on the adhesion of zirconia to dentin using conventional and self-adhesive cements and their corresponding adhesive resins. The occlusal parts of human molars (N=80) were sectioned, exposing the dentin. The teeth and zirconia cylinders (N=80) (diameter=3.4 mm; height=4 mm) were randomly divided into eight groups according to the factors "surface conditioning" and "cement type" (n=10 per group). One conventional cement (CC: RelyX ARC, 3M ESPE) and one self-adhesive cement (SA: RelyX U200, 3M ESPE) and their corresponding adhesive resin (for CC, Adper Single Bond Plus; for SA, Scotchbond Universal Adhesive-SU) were applied on dentin. Zirconia specimens were conditioned either using chairside (CJ: CoJet, 30 μm, 2.5 bar, four seconds), laboratory silica coating (RC: Rocatec, 110 μm, 2.5 bar, four seconds), or universal primer (Single Bond Universal-UP). Nonconditioned groups for both cements acted as the control (C). Specimens were stored in water (37°C, 30 days) and subjected to shear bond strength (SBS) testing (1 mm/min). Data (MPa) were analyzed using two-way analysis of variance and a Tukey test (α=0.05). While surface conditioning significantly affected the SBS values (p=0.0001) (Cadhesive. Air-abrasion and the use of the universal primer improved the bond strength of zirconia to dentin compared to the control group, regardless of the type of resin cement used.

  19. Investigation of the shear bond strength to dentin of universal adhesives applied with two different techniques

    Directory of Open Access Journals (Sweden)

    Elif Yaşa

    2017-09-01

    Full Text Available Objective: The aim of this study was to evaluate the shear bond strength of universal adhesives applied with self-etch and etch&rinse techniques to dentin. Materials and Method: Fourty-eight sound extracted human third molars were used in this study. Occlusal enamel was removed in order to expose the dentinal surface, and the surface was flattened. Specimens were randomly divided into four groups and were sectioned vestibulo-lingually using a diamond disc. The universal adhesives: All Bond Universal (Group 1a and 1b, Gluma Bond Universal (Group 2a and 2b and Single Bond Universal (Group 3a and 3b were applied onto the tooth specimens either with self-etch technique (a or with etch&rinse technique (b according to the manufacturers’ instructions. Clearfil SE Bond (Group 4a; self-etch and Optibond FL (Group 4b; etch&rinse were used as control groups. Then the specimens were restored with a nanohybrid composite resin (Filtek Z550. After thermocycling, shear bond strength test was performed with a universal test machine at a crosshead speed of 0.5 mm/min. Fracture analysis was done under a stereomicroscope (×40 magnification. Data were analyzed using two-way ANOVA and post-hoc Tukey tests. Results: Statistical analysis showed significant differences in shear bond strength values between the universal adhesives (p<0.05. Significantly higher bond strength values were observed in self-etch groups (a in comparison to etch&rinse groups (b (p<0.05. Among all groups, Single Bond Universal showed the greatest shear bond strength values, whereas All Bond Universal showed the lowest shear bond strength values with both application techniques. Conclusion: Dentin bonding strengths of universal adhesives applied with different techniques may vary depending on the adhesive material. For the universal bonding agents tested in this study, the etch&rinse technique negatively affected the bond strength to dentin.

  20. The combined use of Er,Cr:YSGG laser and fluoride to prevent root dentin demineralization

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    Vinícius Rangel GERALDO-MARTINS

    2014-10-01

    Full Text Available The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria. Objective: To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz irradiation associated with 2% neutral sodium fluoride (NaF to prevent root dentin demineralization. Material and Methods: One hundred human root dentin samples were divided into 10 groups (G and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2 with water cooling (WC=5.4 mL/min; G4: laser (4.64 J/cm2 without WC; G5: laser (8.92 J/cm2 with WC; G6: laser (8.92 J/cm2 without WC; G7: laser (4.64 J/cm2 with WC and NaF; G8: laser (4.64 J/cm2 without WC and NaF; G9: laser (8.92 J/cm2 with WC and NaF; G10: laser (8.92 J/cm2 without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN test was done at different depths (30, 60, 90 and 120 μm from the outer dentin surface. Data were analyzed by one-way ANOVA and Fisher’s test (α=5%. Results: The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (p<0.05. Conclusions: The use of Er,Cr:YSGG laser irradiation at 4.64 J/ cm2 and 8.92 J/cm2 without water cooling and associated with 2% NaF can increase the acid resistance of human root dentin.

  1. Archaeology at the micro-scale: micromorphology and phytoliths at a Swahili stonetown

    DEFF Research Database (Denmark)

    Sulas, Federica; Madella, Marco

    2012-01-01

    Geoarchaeological and archaeobotanical techniques are increasingly applied to the study of urban and domestic space. However, they are seldom performed as part of an integrative approach, where the soil and botanical micro-records are used together. This paper presents the preliminary results of ...... from Songo Mnara, this paper illustrates the potential of integrating geoarchaeology and archaeobotany to investigate the use of space in urban contexts. The approach is a novelty within the context of Swahili archaeology and an emerging one in Africa.......Geoarchaeological and archaeobotanical techniques are increasingly applied to the study of urban and domestic space. However, they are seldom performed as part of an integrative approach, where the soil and botanical micro-records are used together. This paper presents the preliminary results...... of ongoing research at Songo Mnara in Tanzania that combines customised intra-site soil macro- and micromorphological analyses, chemical analysis and the study of phytoliths. The research is part of a multidisciplinary project on the use of urban space in Swahili stonetowns. By eliciting multiple datasets...

  2. Chemical Species, Micromorphology, and XRD Fingerprint Analysis of Tibetan Medicine Zuotai Containing Mercury.

    Science.gov (United States)

    Li, Cen; Yang, Hongxia; Du, Yuzhi; Xiao, Yuancan; Zhandui; Sanglao; Wang, Zhang; Ladan, Duojie; Bi, Hongtao; Wei, Lixin

    2016-01-01

    Zuotai ( gTso thal ) is one of the famous drugs containing mercury in Tibetan medicine. However, little is known about the chemical substance basis of its pharmacodynamics and the intrinsic link of different samples sources so far. Given this, energy dispersive spectrometry of X-ray (EDX), scanning electron microscopy (SEM), atomic force microscopy (AFM), and powder X-ray diffraction (XRD) were used to assay the elements, micromorphology, and phase composition of nine Zuotai samples from different regions, respectively; the XRD fingerprint features of Zuotai were analyzed by multivariate statistical analysis. EDX result shows that Zuotai contains Hg, S, O, Fe, Al, Cu, and other elements. SEM and AFM observations suggest that Zuotai is a kind of ancient nanodrug. Its particles are mainly in the range of 100-800 nm, which commonly further aggregate into 1-30  μ m loosely amorphous particles. XRD test shows that β -HgS, S 8 , and α -HgS are its main phase compositions. XRD fingerprint analysis indicates that the similarity degrees of nine samples are very high, and the results of multivariate statistical analysis are broadly consistent with sample sources. The present research has revealed the physicochemical characteristics of Zuotai , and it would play a positive role in interpreting this mysterious Tibetan drug.

  3. BOND STRENGTH OF SELF-ETCH ADHESIVES WITH PRIMARY AND PERMANENT TEETH DENTIN – IN VITRO STUDY.

    Directory of Open Access Journals (Sweden)

    Natalia Gateva

    2012-03-01

    Full Text Available Objective: The aim of this study was to compare dentin bond strength of primary and permanent teeth with self-etching adhesive systems. Methods: On 40 intact specimens of primary and permanent teeth was created flat dentin surfaces. The patterns were divided in 4 groups. Two different self-etching adhesive systems were used – one two steps (AdheSE, VivaDent and one one step (AdheSE One, VivaDent. Resin composite build-ups were constructed by means of convetional copper ring after applying the adhesive. The specimens were stored in water for 72 h at room temperature. After that specimens were tested for macrotensile bond strength. Debonded surfaces were analyzed by SEM.Conclusions: The measured values of dentin bond strength after applying self-etching adhesives are statistically significant in group of permanent teeth in comparison with group of primary teeth, and for both adhesive generations. Two steps self-etching adhesive provide significant stronger dentin bond strength with both dentitions in comparison with one step self-etching adhesive.

  4. Carbodiimide Inactivation of MMPs and Effect on Dentin Bonding

    Science.gov (United States)

    Mazzoni, A.; Apolonio, F.M.; Saboia, V.P.A.; Santi, S.; Angeloni, V.; Checchi, V.; Curci, R.; Di Lenarda, R.; Tay, F.R.; Pashley, D.H.; Breschi, L.

    2014-01-01

    The use of protein cross-linking agents during bonding procedures has been recently proposed to improve bond durability. This study aimed to use zymography and in situ zymography techniques to evaluate the ability of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linker to inhibit matrix metalloproteinase (MMP) activity. The hypotheses tested were that: (1) bonding procedures increase dentin gelatinolytic activity and (2) EDC pre-treatment prevents this enzymatic activity. The zymographic assay was performed on protein extracts obtained from dentin powder treated with Optibond FL or Scotchbond 1XT with or without 0.3M EDC pre-treatment. For in situ zymography, adhesive/dentin interfaces were created with the same adhesives applied to acid-etched dentin slabs pre-treated or not with EDC conditioner. Zymograms revealed increased expression of dentin endogenous MMP-2 and -9 after adhesive application, while the use of EDC as a primer inactivated dentin gelatinases. Results of in situ zymograpy showed that hybrid layers of tested adhesives exhibited intense collagenolytic activity, while almost no fluorescence signal was detected when specimens were pre-treated with EDC. The correlative analysis used in this study demonstrated that EDC could contribute to inactivate endogenous dentin MMPs within the hybrid layer created by etch-and-rinse adhesives. PMID:24334409

  5. Dentin biomodification: strategies, renewable resources and clinical applications.

    Science.gov (United States)

    Bedran-Russo, Ana K; Pauli, Guido F; Chen, Shao-Nong; McAlpine, James; Castellan, Carina S; Phansalkar, Rasika S; Aguiar, Thaiane R; Vidal, Cristina M P; Napotilano, José G; Nam, Joo-Won; Leme, Ariene A

    2014-01-01

    The biomodification of dentin is a biomimetic approach, mediated by bioactive agents, to enhance and reinforce the dentin by locally altering the biochemistry and biomechanical properties. This review provides an overview of key dentin matrix components, targeting effects of biomodification strategies, the chemistry of renewable natural sources, and current research on their potential clinical applications. The PubMed database and collected literature were used as a resource for peer-reviewed articles to highlight the topics of dentin hierarchical structure, biomodification agents, and laboratorial investigations of their clinical applications. In addition, new data is presented on laboratorial methods for the standardization of proanthocyanidin-rich preparations as a renewable source of plant-derived biomodification agents. Biomodification agents can be categorized as physical methods and chemical agents. Synthetic and naturally occurring chemical strategies present distinctive mechanism of interaction with the tissue. Initially thought to be driven only by inter- or intra-molecular collagen induced non-enzymatic cross-linking, multiple interactions with other dentin components are fundamental for the long-term biomechanics and biostability of the tissue. Oligomeric proanthocyanidins show promising bioactivity, and their chemical complexity requires systematic evaluation of the active compounds to produce a fully standardized intervention material from renewable resource, prior to their detailed clinical evaluation. Understanding the hierarchical structure of dentin and the targeting effect of the bioactive compounds will establish their use in both dentin-biomaterials interface and caries management. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. A micromechanics model of the elastic properties of human dentine

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    Kinney, J. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Balooch, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Marshall, G. W. [Univ. of California, San Francisco, CA (United States). Dept. of Restorative Dentistry; Marshall, S. J. [Univ. of California, San Francisco, CA (United States). Dept. of Restorative Dentistry

    1999-10-01

    A generalized self-consistent model of cylindrical inclusions in a homogeneous and isotropic matrix phase was used to study the effects of tubule orientation on the elastic properties of dentin. Closed form expressions for the five independent elastic constants of dentin were derived in terms of tubule concentration, and the Young's moduli and Poisson ratios of peri- and intertubular dentin. An atomic force microscope (AFM) indentation technique determined the Young's moduli of the peri- and intertubular dentin as approximately 30 GPa and 15 GPa, respectively. Over the natural variation in tubule density found in dentin, there was only a slight variation in the axial and transverse shear moduli with position in the tooth, and there was no measurable effect of tubule orientation. We conclude that tubule orientation has no appreciable effect on the elastic behavior of normal dentin, and that the elastic properties of healthy dentin can be modeled as an isotropic continuum with a Young's modulus of approximately 16 GPa and a shear modulus of 6.2 GPa.

  7. Dietary adaptions in the ultrastructure of dinosaur dentine.

    Science.gov (United States)

    Brink, Kirstin S; Chen, Yu-Cheng; Wu, Ya-Na; Liu, Wei-Min; Shieh, Dar-Bin; Huang, Timothy D; Sun, Chi-Kuang; Reisz, Robert R

    2016-12-01

    Teeth are key to understanding the feeding ecology of both extant and extinct vertebrates. Recent studies have highlighted the previously unrecognized complexity of dinosaur dentitions and how specific tooth tissues and tooth shapes differ between taxa with different diets. However, it is unknown how the ultrastructure of these tooth tissues contributes to the differences in feeding style between taxa. In this study, we use third harmonic generation microscopy and scanning electron microscopy to examine the ultrastructure of the dentine in herbivorous and carnivorous dinosaurs to understand how the structure of this tissue contributes to the overall utility of the tooth. Morphometric analyses of dentinal tubule diameter, density and branching rates reveal a strong signal for dietary preferences, with herbivorous saurischian and ornithischian dinosaurs consistently having higher dentinal tubule density than their carnivorous relatives. We hypothesize that this relates to the hardness of the dentine, where herbivorous taxa have dentine that is more resistant to breakage and wear at the dentine-enamel junction than carnivorous taxa. This study advocates the detailed study of dentine and the use of advanced microscopy techniques to understand the evolution of dentition and feeding ecology in extinct vertebrates. © 2016 The Author(s).

  8. Adhesion of resin composite core materials to dentin.

    Science.gov (United States)

    O'Keefe, K L; Powers, J M

    2001-01-01

    This study determined (1) the effect of polymerization mode of resin composite core materials and dental adhesives on the bond strength to dentin, and (2) if dental adhesives perform as well to dentin etched with phosphoric acid as to dentin etched with self-etching primer. Human third molars were sectioned 2 mm from the highest pulp horn and polished. Three core materials (Fluorocore [dual cured], Core Paste [self-cured], and Clearfil Photo Core [light cured]) and two adhesives (Prime & Bond NT Dual Cure and Clearfil SE Bond [light cured]) were bonded to dentin using two dentin etching conditions. After storage, specimens were debonded in microtension and bond strengths were calculated. Scanning electron micrographs of representative bonding interfaces were analyzed. Analysis showed differences among core materials, adhesives, and etching conditions. Among core materials, dual-cured Fluorocore had the highest bond strengths. There were incompatibilities between self-cured Core Paste and Prime & Bond NT in both etched (0 MPa) and nonetched (3.0 MPa) dentin. Among adhesives, in most cases Clearfil SE Bond had higher bond strengths than Prime & Bond NT and bond strengths were higher to self-etched than to phosphoric acid-etched dentin. Scanning electron micrographs did not show a relationship between resin tags and bond strengths. There were incompatibilities between a self-cured core material and a dual-cured adhesive. All other combinations of core materials and adhesives produced strong in vitro bond strengths both in the self-etched and phosphoric acid-etched conditions.

  9. Influence of Air Abrasion and Sonic Technique on Microtensile Bond Strength of One-Step Self-Etch Adhesive on Human Dentin

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    Baraba Anja

    2015-01-01

    Full Text Available The purpose of this in vitro study was to evaluate the microtensile bond strength of one-step self-etch adhesive to human dentin surface modified with air abrasion and sonic technique and to assess the morphological characteristics of the pretreated dentin surface. The occlusal enamel was removed to obtain a flat dentin surface for thirty-six human molar teeth. The teeth were randomly divided into three experimental groups (n = 12 per group, according to the pretreatment of the dentin: (1 control group, (2 air abrasion group, and (3 sonic preparation group. Microtensile bond strength test was performed on a universal testing machine. Two specimens from each experimental group were subjected to SEM examination. There was no statistically significant difference in bond strength between the three experimental groups (P > 0.05. Mean microtensile bond strength (MPa values were 35.3 ± 12.8 for control group, 35.8 ± 13.5 for air abrasion group, and 37.7 ± 12.0 for sonic preparation group. The use of air abrasion and sonic preparation with one-step self-etch adhesive does not appear to enhance or impair microtensile bond strength in dentin.

  10. Evaluation of the bond strength of resin cements used to lute ceramics on laser-etched dentin.

    Science.gov (United States)

    Giray, Figen Eren; Duzdar, Lale; Oksuz, Mustafa; Tanboga, Ilknur

    2014-07-01

    The purpose of this study was to investigate the shear bond strength (SBS) of two different adhesive resin cements used to lute ceramics on laser-etched dentin. Erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser irradiation has been claimed to improve the adhesive properties of dentin, but results to date have been controversial, and its compatibility with existing adhesive resin cements has not been conclusively determined. Two adhesive cements, one "etch-and-rinse" [Variolink II (V)] and one "self-etch" [Clearfil Esthetic Cement (C)] luting cement, were used to lute ceramic blocks (Vita Celay Blanks, Vita) onto dentin surfaces. In total, 80 dentin specimens were distributed randomly into eight experimental groups according to the dentin surface-etching technique used Er,Cr:YSGG laser and Er:YAG laser: (1) 37% orthophosphoric acid+V (control group), (2) Er,Cr:YSGG laser+V, (3) Er,Cr:YSGG laser+acid+V, (4) Er:YAG laser+V, (5) Er:YAG laser+acid+V, (6) C, (7) Er,Cr:YSGG laser+C, and (8) Er:YAG laser+C. Following these applications, the ceramic discs were bonded to prepared surfaces and were shear loaded in a universal testing machine until fracture. SBS was recorded for each group in MPa. Shear test values were evaluated statistically using the Mann-Whitney U test. No statistically significant differences were evident between the control group and the other groups (p>0.05). The Er,Cr:YSGG laser+A+V group demonstrated significantly higher SBS than did the Er,Cr:YSGG laser+V group (p=0.034). The Er,Cr:YSGG laser+C and Er:YAG laser+C groups demonstrated significantly lower SBS than did the C group (pceramic bond strengths, depending upon the adhesive cement used.

  11. Dentinal tubules revealed with X-ray tensor tomography.

    Science.gov (United States)

    Jud, Christoph; Schaff, Florian; Zanette, Irene; Wolf, Johannes; Fehringer, Andreas; Pfeiffer, Franz

    2016-09-01

    Dentin is a mineralized material making up most of the tooth bulk. A system of microtubules, so called dentinal tubules, transverses it radially from the pulp chamber to the outside. This highly oriented structure leads to anisotropic mechanical properties directly connected to the tubules orientation and density: the ultimate tensile strength as well as the fracture toughness and the shear strength are largest perpendicular to dentinal tubules. Consequently, the fatigue strength depends on the direction of dentinal tubules, too. However, none of the existing techniques used to investigate teeth provide access to orientation and density of dentinal tubules for an entire specimen in a non-destructive way. In this paper, we measure a third molar human tooth both with conventional micro-CT and X-ray tensor tomography (XTT). While the achievable resolution in micro-CT is too low to directly resolve the dentinal tubules, we provide strong evidence that the direction and density of dentinal tubules can be indirectly measured by XTT, which exploits small-angle X-ray scattering to retrieve a 3D map of scattering tensors. We show that the mean directions of scattering structures correlate to the orientation of dentinal tubules and that the mean effective scattering strength provides an estimation of the relative density of dentinal tubules. Thus, this method could be applied to investigate the connection between tubule orientation and fatigue or tensile properties of teeth for a full sample without cutting one, non-representative peace of tooth out of the full sample. Copyright © 2016 The Academy of Dental Materials. All rights reserved.

  12. Effect of Pre-heating on Microtensile Bond Strength of Composite Resin to Dentin.

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    Abdolrahim Davari

    2014-10-01

    Full Text Available Direct composite resin restorations are widely used and the impact of different storage temperatures on composites is not well understood. The purpose of this study was to evaluate the microtensile bond strength of composite to dentin after different pre-curing temperatures.Occlusal surfaces of 44 human molars were ground with diamond burs under water coolant and polished with 600 grit silicon carbide papers to obtain flat dentin surfaces. The dentin was etched with 37% phosphoric acid and bonded with Adper Single Bond 2 according to the manufacturer's instructions. The specimens were randomly divided into two groups (n=22 according to the composite resin applied: FiltekP60 and Filtek Z250. Each group included three subgroups of composite resin pre-curing temperatures (4°C, 23°C and 37°C. Composite resins were applied to the dentin surfaces in a plastic mold (8mm in diameter and 4mm in length incrementally and cured. Twenty-two composite-to-dentin hour-glass sticks with one mm(2 cross-sectional area per group were prepared. Microtensile bond strength measurements were made using a universal testing machine at a crosshead speed of one mm/min. For statistical analysis, t-test, one-way and two-way ANOVA were used. The level of significance was set at P<0.05.Filtek P60 pre-heated at 37ºC had significantly higher microtensile bond strength than Filtek Z250 under the same condition. The microtensile bond strengths were not significantly different at 4ºC, 23ºC and 37ºC subgroups of each composite resin group.Filtek P60 and Filtek Z250 did not have significantly different microtensile bond strengths at 4ºC and 23ºC but Filtek P60 had significantly higher microtensile bond strength at 37 ºC. Composite and temperature interactions had significant effects on the bond strength.

  13. [Influence of thermalcycling on bonding durability of self-etch adhesives with dentin].

    Science.gov (United States)

    Tian, Fu-cong; Wang, Xiao-yan; Gao, Xue-jun

    2014-04-18

    To investigate influence of thermalcycling on the bonding durability of two one-step products [Adper Prompt (AP) and G-bond (GB)] and one two-step self-etching adhesive [Clearfil SE bond (SE)] with dentin in vitro. Forty-two extracted human molars were selected. The superficial dentin was exposed by grinding off the enamel. The teeth were randomly distributed into six groups with varied bonding protocols. The adhesives were applied to the dentin surface. Composite crowns were built up, then the samples were cut longitudinally into sticks with 1.0 mm×1.0 mm bonding area [for microtensile bond strength (MTBS) testing] or 1.0 mm thick slabs (for nanoleakage observation). Bonding performance was evaluated with or without thermalcyling. For the MTBS testing, the strength values were statistically analysed using One-Way ANOVA. Four slabs in each group were observed for nanoleakage by SEM with a backscattered electron detector. Thermalcycling procedures affected MTBS. In the two one-step groups, the MTBS decreased significantly (Padhesives showed lower MTBS than two-step bonding system after aging.For AP and GB, continuous nanoleakage appearance was notable and more obvious than for SE. Thermalcycling can affect the bonding performance of self-etch adhesives including decrease of bond strength and nanoleakage pattern. one-step self-etch adhesives showed more obvious change compared with their two-step counterparts.

  14. Influence of disinfectant solutions on the tensile bond strength of a fourth generation dentin bonding agent

    Directory of Open Access Journals (Sweden)

    BOCANGEL Jorge Saldivar

    2000-01-01

    Full Text Available The purpose of the present study was to evaluate the influence of different disinfectant solutions on the tensile bond strength of a fourth generation dentin bonding agent. Forty non carious human molars were selected. Teeth were embedded in acrylic resin and ground until the exposure of a flat superficial dentin surface. Teeth were randomly divided in 4 groups and treated as follows: Group 1 - 2.5% NaOCl for 40 seconds; Group 2 - 2% chlorhexidine for 40 seconds; Group 3 - 1.23% acidulated fluoride for 4 minutes; and Group 4 - control (without disinfectant solution. Following treatments, Scotchbond Multipurpose Plus® (3M was used according to the manufacturer's instructions. After that, the test specimens were built with composite resin (Z100®-3M, using a standard Teflon matrix. The specimens were stored in distilled water for 24 hours at a temperature of 37ºC. The tensile strength test was performed using a Mini Instrom testing machine. The mean values obtained for each group, in MPa, were: Group 1 - 7.37 (± 2.51; Group 2 - 11.25 (± 4.65; Group 3 - 9.80 (± 3.11; and Group 4 - 10.96 (± 3.37. The results were submitted to statistical analysis using the ANOVA test, and no statistical significant differences among the groups were found. It can be concluded that the different disinfectant substances used in this research do not adversely affect dentin adhesion.

  15. Dentin-bonded all-ceramic crowns: current status.

    Science.gov (United States)

    Burke, F J; Qualtrough, A J; Hale, R W

    1998-04-01

    Dentin-bonded all-ceramic crowns employ contemporary techniques to lute the crown to the tooth using a resin luting material and dentin-bonding system. The advantages of these crowns are that they provide good esthetics and fracture resistance and can be used in cases of substantial tooth loss. Their principal disadvantages are that the luting procedure is more time-consuming and that these crowns should not be used where margins are subgingival. Dentin-bonded all-ceramic crowns may be a useful addition to the dentist's armamentarium, but long-term clinical studies are needed to fully assess their performance.

  16. Temperature increase beneath etched dentin discs during composite polymerization.

    Science.gov (United States)

    Karaarslan, Emine Sirin; Secilmis, Asli; Bulbul, Mehmet; Yildirim, Cihan; Usumez, Aslihan

    2011-01-01

    The purpose of this in vitro study was to measure the temperature increase during the polymerization of a composite resin beneath acid-etched or laser-etched dentin discs. The irradiation of dentin with an Er:YAG laser may have a positive effect on the thermal conductivity of dentin. This technique has not been studied extensively. Forty dentin discs (5 mm in diameter and 0.5 or 1 mm in height) were prepared from extracted permanent third molars. These dentin discs were etched with 20% orthophosphoric acid or an Er:YAG laser, and were then placed on an apparatus developed to measure temperature increases. The composite resin was polymerized with a high-intensity quartz tungsten halogen (HQTH) or light-emitting diode unit (LED). The temperature increase was measured under the dentin disc with a J-type thermocouple wire that was connected to a data logger. Five measurements were made for each dentin disc, curing unit, and etching system combination. Differences between the initial and the highest temperature readings were taken, and the five calculated temperature changes were averaged to determine the value of the temperature increase. Statistical analysis was performed with a three-way ANOVA and Tukey HSD tests at a 0.05 level of significance. Further SEM examinations were performed. The temperature increase values varied significantly, depending on etching systems (p < 0.05), dentin thicknesses (p < 0.05), and curing units (p < 0.05). Temperature increases measured beneath laser-etched discs were significantly higher than those for acid-etched dentin discs (p < 0.05). The HQTH unit induced significantly higher temperature increases than the LED unit (p < 0.05). The LED unit induced the lowest temperature change (5.2°C) in the 1-mm, acid-etched dentin group. The HQTH unit induced the highest temperature change (10.4°C) for the 0.5-mm, laser-etched dentin group. The risk of heat-induced pulpal damage should be taken into consideration

  17. Comparison of Dentin Permeability After Tooth Cavity Preparation with Diamond Bur and Er:YAG Laser

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    Masoumeh Hasani Tabatabaei

    2016-05-01

    Full Text Available Objectives: The aim of this study was to compare the permeability of dentin after using diamond bur and Er:YAG laser.Materials and Methods: Seventy-two recently extracted, intact, and restoration-free human permanent molars were used in this study. The samples were randomly divided into three groups of 24 each and class I cavities were prepared as follows. Group 1: High speed diamond bur with air and water spray. Group 2: Er:YAG laser. Group 3: Er:YAG laser followed by additional sub-ablative laser treatment. Each group consisted of two subgroups with different cavity depths of 2mm and 4mm.  The entire cavity floor was in dentin. Two samples from each subgroup were observed under scanning electron microscope (SEM. The external surfaces of other samples were covered with nail varnish (except the prepared cavity and immersed in 0.5% methylene blue solution for 48 hours.  After irrigation of samples with water, they were sectioned in bucco-lingual direction. Then, the samples were evaluated under a stereomicroscope at ×160 magnification. The data were analyzed using two-way ANOVA and Tukey’s HSD test.Results: Two-way ANOVA showed significant difference in permeability between groups 2 and 3 (laser groups with and without further treatment and group 1 (bur group. The highest permeability was seen in the group 1. There was no significant difference in dentin permeability between groups 2 and 3 and no significant difference was observed between different depths (2mm and 4mm.Conclusion: Cavities prepared by laser have less dentin permeability than cavities prepared by diamond bur.

  18. Hybridization quality and bond strength of adhesive systems according to interaction with dentin.

    Science.gov (United States)

    Salvio, Luciana Andrea; Hipólito, Vinicius Di; Martins, Adriano Luis; de Goes, Mario Fernando

    2013-07-01

    To evaluate the hybridization quality and bond strength of adhesives to dentin. Ten human molars were ground to expose the dentin and then sectioned in four tooth-quarters. They were randomly divided into 5 groups according to the adhesive used: Two single-step self-etch adhesives - Adper Prompt (ADP) and Xeno III (XE), two two-step self-etching primer systems - Clearfil SE Bond (SE) and Adhe SE (ADSE), and one one-step etch-and-rinse system - Adper Single Bond (SB). Resin composite (Filtek Z250) crown buildups were made on the bonded surfaces and incrementally light-cured for 20 s. The restored tooth-quarters were stored in water at 37°C for 24 h and then sectioned into beams (0.8 mm(2) in cross-section). Maximal microtensile bond strength (μ-TBS) was recorded (0.5 mm/min in crosshead speed). The results were submitted to one-way ANOVA and Tukey's test (α = 0.05). Thirty additional teeth were used to investigate the hybridization quality by SEM using silver methenamine or ammoniacal silver nitrate dyes. SE reached significantly higher μ-TBS (P 0.05), and between SB and ADP (P > 0.05); ADSE and XE were significantly higher than SB and ADP (P quality than that observed for ADP and XE. The bond strength and hybridization quality were affected by the interaction form of the adhesives with dentin. The hybridization quality was essential to improve the immediate μ-TBS to dentin.

  19. The effect of root canal preparation on the development of dentin cracks.

    Science.gov (United States)

    Milani, Amin Salem; Froughreyhani, Mohammad; Rahimi, Saeed; Jafarabadi, Mohammad Asghari; Paksefat, Sara

    2012-01-01

    Root fracture is not an instant phenomenon but a result of gradual development of tiny craze lines in tooth structure. Recent studies have shown that canal instrumentation has the potential to cause dentinal cracks. The purpose of this study was to evaluate and compare the formation of dentinal cracks caused by ProTaper rotary system to hand instrumentation. This in vitro study was carried out using 57 mandible incisor teeth. The teeth were decoronated. The roots were then examined to exclude cracked samples. A standard model for PDL simulation was used. The teeth were randomly divided into two experimental and one control group (n=19). The teeth in the experimental groups were prepared using hand or ProTaper Universal rotary instrumentation. The teeth in the control group were left unprepared. The teeth were then sectioned horizontally 3 and 6 mm from the apex, and the number of various dentinal defects was recorded using a dental operating microscope. The differences between groups were analyzed with Fisher's exact test. The hand group demonstrated significantly more defects than the control group (P=0.001). However, there was no significant difference between the rotary compared to the control and hand groups (P>0.05). There was no significant difference between groups with regards to fracture (P>0.05). Other defects including internal, external and surface cracks were more frequent in the hand than in the control or rotary groups (P=0.02), but the difference was not significant between the rotary and control groups (P>0.05). Canal preparation, whether hand or rotary, produces structural defects in dentin. The ProTaper rotary system when used according to the manufacturer's instructions, tends to produce fewer cracks and can be considered a safe preparation technique.

  20. Effect of adhesive system and application strategy on reduction of dentin permeability

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    Adriana Oliveira Carvalho

    2012-10-01

    Full Text Available This study evaluated the effect of adhesive systems and application strategies on dentin hydraulic conductance (HC. The buccal enamel was removed from bovine incisors to simulate laminate cavity preparations. After removing the roots and the coronal pulp, the buccal dentin was treated with EDTA solution (0.5 M for 5 minutes, rinsed, ultrasonicated for 12 minutes and connected to a permeability device. HC of the specimens was measured at 10 psi (n = 5. Permeability was measured before and after bonding procedures using G-Bond (GB, Clearfil Tri-S Bond (CTS, Hybrid Coat (HY, Bond Force (BF, Adper Easy Bond (AEB Silorane (SI, Clearfil SE Bond (CSE and Adper Scotchbond Multi-Purpose (SMP adhesives systems, which were applied following three strategies: 1 according to the manufacturers' instructions; 2 two coats of all-in-one self-etching adhesives (GB, CTS, HY, BF, AEB or priming step plus two coats of bonding resin for the other systems (SI, CSE and SMP; and 3 a thin layer of a flowable composite applied over one coat of all-in-one self-etching adhesives or primed surface for SI, CSE and SMP adhesives. No significant difference was observed among the application modes concerning their ability to reduce HC. None of the adhesives showed complete sealing (100% of the bovine tooth dentin. SI exhibited lower HC than SMP, however, they were not significantly different from the other systems. The results suggest that all systems tested result in an HC reduction of more than 90%. The wet bonding technique seemed to be more sensitive for dentin sealing.

  1. Effects of chlorhexidine-containing adhesives on the durability of resin-dentine interfaces.

    Science.gov (United States)

    Stanislawczuk, Rodrigo; Pereira, Fabiane; Muñoz, Miguel Angel; Luque, Issis; Farago, Paulo Vitor; Reis, Alessandra; Loguercio, Alessandro D

    2014-01-01

    This study evaluated the effect of addition of diacetate CHX in different concentrations into two simplified etch-and-rinse (ER) adhesive systems (XP Bond [XP] and Ambar {AM}) on the ultimate tensile strength (UTS), degree of conversion (DC), 60-day cumulative water sorption (WS), solubility (SO) and CHX release (CR) as well as the immediate (IM) and 1-year (1Y) resin-dentine bond strength (μTBS) and nanoleakage (NL). Ten experimental adhesive systems were formulated according to the addition of CHX diacetate (0 [control], 0.01, 0.05, 0.1 and 0.2%) in the two ER. For UTS and DC, specimens were constructed and tested after 24h. For WS, SO and CR, after specimens build-up, they were stored in water and the properties measured after 60 days. The occlusal enamel of fifty molars was removed and the adhesives were applied in dentine surface after 37% phosphoric acid etching. After composite resin build-ups, specimens were longitudinally sectioned to obtain resin-dentine bonded sticks (0.8mm(2)). Specimens were tested in tension at 0.5mm/min in the IM or 1Y. For NL, 2 bonded sticks from each tooth were prepared and analyzed under SEM. The data were submitted to appropriate statistical analysis (α=0.05). The addition of CHX did not influence UTS, DC, WS and SO (padhesives with higher concentration of CHX (padhesives or it was less pronounced than the control (XP) regardless of the CHX concentration. The addition of CHX diacetate in concentrations until 0.2% in the simplified ER adhesive systems may be an alternative to increase the long-term stability of resin-dentine interfaces, without jeopardizing the adhesives' mechanical properties evaluated. Copyright © 2013. Published by Elsevier Ltd.

  2. Influence of EDC on Dentin-Resin Shear Bond Strength and Demineralized Dentin Thermal Properties

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    Lin Tang

    2016-11-01

    Full Text Available This study aimed to evaluate the bonding strength and thermal properties of demineralized dentin with and without EDC treatment. Sound human molars were randomly divided into seven treatment groups (n = 20: control, 80% ethanol, and five EDC ethanol solutions (0.01–1.0 M. In each group, 16 samples were used for bond strength assessment and 4 samples were used for scanning electron microscopy (SEM analysis. A further 70 intact molars were used to obtain a fine demineralized dentin powder, treated with the same solutions and were evaluated the crosslink degree by ninhydrin test and denaturation temperature (Td by differential scanning calorimetry. EDC-treated specimens (<1.0 M had a higher bond strength, especially 0.3 and 0.5 M group, than the control counterpart. There was a significant drop in bond strength of 1.0 M EDC group. SEM revealed a homogeneous and regular interface under all treatments. EDC treatment significantly increased the demineralized dentin cross-link degree and Td compared with the control and ethanol treatments. The 0.3 and 0.5 M treatments showed the highest cross-link degree and Td. In terms of mechnical and theramal properties consideration, 0.3 and 0.5 M EDC solutions may be favorable for when applied with etch-and-rinse adhesives, but it is still needed further long-term study.

  3. The influence of salivary contamination on shear bond strength of dentin adhesive systems.

    Science.gov (United States)

    Park, Jeong-won; Lee, Kyung Chae

    2004-01-01

    This study evaluated the influence of salivary contamination during dentin bonding procedures on shear bond strength and investigated the effect of contaminant-removing treatments on the recovery of bond strength for two dentin bonding agents. One hundred and ten human molars were embedded in cylindrical molds with self-curing acrylic resin. The occlusal dentin surface was exposed by wet grinding with #800 silicon carbide abrasive paper. The teeth were divided into five groups for One-step (OS) (BISCO, Inc) and six groups for Clearfil SE Bond (SE) (Kuraray Co, Ltd, Osaka, Japan). For One-step, the grinding surface was treated with 32% phosphoric acid; BAC (BISCO Inc) and divided into five groups: OS control group (uncontaminated), OS I (salivary contamination, blot dried), OS II (salivary contamination, completely dried), OS III (salivary contamination, wash and blot dried) and OS IV (salivary contamination, re-etching for 10 seconds, wash and blot dried). For SE bond, the following surface treatments were done: SE control group (primer applied to the fresh dentin surface), SE I (after salivary contamination, primer applied), SE II (primer, salivary contamination, dried), SE III (primer, salivary contamination, wash and dried), SE IV (after procedure of SE II, re-application of primer) and SE V (after procedure of SE III, re-application of primer). Each bonding agent was applied and light cured for 10 seconds. Clearfil AP-X (Kuraray Co, Ltd) composite was packed into the Ultradent mount jig mold and light cured for 40 seconds. The bonded specimens were stored for 24 hours in a 37 degrees C waterbath. The shear bond strengths were measured using an Instron testing machine (Model 4202, Instron Corp). The data for each group were subjected to one-way ANOVA followed by the Newman-Keuls test to make comparisons among the groups. The results were as follows: In the One-step groups, the OS II group showed statistically significant lower shear bond strength than the OS

  4. Microchemical and structural regular variability of apatites in 'overbuilt' enamel and dentin of human molar teeth

    International Nuclear Information System (INIS)

    Kuczumow, A.; Nowak, J.; ChaLas, R.

    2011-01-01

    The aim of a recent paper was to recognize the chemical and structural changes in apatites, which form both the enamel and the dentin of the human tooth. The aim was achieved by scrutinizing the linear elemental profiles along the cross-sections of human molar teeth. Essentially, the task was accomplished with the application of the Electron Probe Microanalysis method and with some additional studies by Micro-Raman spectrometry. All the trends in linear profiles were strictly determined. In the enamel zone they were either increasing or decreasing curves of exponential character. The direction of the investigations was to start with the tooth surface and move towards the dentin-enamel junction (DEJ). The results of the elemental studies were more visible when the detected material was divided, in an arbitrary way, into the prevailing 'core' enamel (∼93.5% of the total mass) and the remaining 'overbuilt' enamel. The material in the 'core' enamel was fully stable, with clearly determined chemical and mechanical features. However, the case was totally different in the 'overbuilt enamel', with dynamic changes in the composition. In the 'overbuilt' layer Ca, P, Cl and F profiles present the decaying distribution curves, whereas Mg, Na, K and CO 3 2- present the growing ones. Close to the surface of the tooth the mixture of hydroxy-, chlor- and fluor-apatite is formed, which is much more resistant than the rest of the enamel. On passing towards the DEJ, the apatite is enriched with Na, Mg and CO 3 2- . In this location, three of six phosphate groups were substituted with carbonate groups. Simultaneously, Mg is associated with the hydroxyl groups around the hexad axis. In this way, the mechanisms of exchange reactions were established. The crystallographic structures were proposed for new phases located close to DEJ. In the dentin zone, the variability of elemental profiles looks different, with the most characteristic changes occurring in Mg and Na concentrations. Mg

  5. Shear bond strength of self-etch and total-etch bonding systems at different dentin depths

    Directory of Open Access Journals (Sweden)

    Ana Carolina Maito Villela-Rosa

    2011-04-01

    Full Text Available The purpose of this study was to evaluate the dentin shear bond strength of four adhesive systems (Adper Single Bond 2, Adper Prompt L-Pop, Magic Bond DE and Self Etch Bond in regards to buccal and lingual surfaces and dentin depth. Forty extracted third molars had roots removed and crowns bisected in the mesiodistal direction. The buccal and lingual surfaces were fixed in a PVC/acrylic resin ring and were divided into buccal and lingual groups assigned to each selected adhesive. The same specimens prepared for the evaluation of superficial dentin shear resistance were used to evaluate the different depths of dentin. The specimens were identified and abraded at depths of 0.5, 1.0, 1.5 and 2.0 mm. Each depth was evaluated by ISO TR 11405 using an EMIC-2000 machine regulated at 0.5 mm/min with a 200 Kgf load cell. We performed statistical analyses on the results (ANOVA, Tukey and Scheffé tests. Data revealed statistical differences (p < 0.01 in the adhesive and depth variation as well as adhesive/depth interactions. The Adper Single Bond 2 demonstrated the highest mean values of shear bond strength. The Prompt L-Pop product, a self-etching adhesive, revealed higher mean values compared with Magic Bond DE and Self Etch Bond adhesives, a total and self-etching adhesive respectively. It may be concluded that the shear bond strength of dentin is dependent on material (adhesive system, substrate depth and adhesive/depth interaction.

  6. Initial and long-term bond strengths of one-step self-etch adhesives with silane coupling agent to enamel-dentin-composite in combined situation.

    Science.gov (United States)

    Mamanee, Teerapong; Takahashi, Masahiro; Nakajima, Masatoshi; Foxton, Richard M; Tagami, Junji

    2015-01-01

    This study evaluated the effect of adding silane coupling agent on initial and long-term bond strengths of one-step self-etch adhesives to enamel-dentin-composite in combined situation. Cervical cavities were prepared on extracted molars and filled with Clearfil AP-X. After water-storage for one-week, the filled teeth were sectioned in halves to expose enamel, dentin and composite surfaces and then enamel-dentin-composite surface was totally applied with one of adhesive treatments (Clearfil SE One, Clearfil SE One with Clearfil Porcelain Bond Activator, Beautibond Multi, Beautibond Multi with Beautibond Multi PR Plus and Scotchbond Universal). After designed period, micro-shear bond strengths (µSBSs) to each substrate were determined. For each period of water-storage, additive silane treatments significantly increased µSBS to composite (penamel (p>0.05). Moreover, the stability of µSBS was depended on materials and substrates used.

  7. Short communication: pre- and co-curing effect of adhesives on shear bond strengths of composite resins to primary enamel and dentine: an in vitro study.

    Science.gov (United States)

    Viswanathan, R; Shashibhushan, K K; Subba Reddy, V V

    2011-12-01

    To evaluate and compare shear bond strengths of composite resins to primary enamel and dentine when the adhesives are pre-cured (light cured before the application of the resin) or co-cured (adhesive and the resin light cured together). Buccal surfaces of 80 caries-free primary molars were wet ground to create bonding surfaces on enamel and dentine and specimens mounted on acrylic blocks. Two bonding agents (Prime and Bond NT® and Xeno III®) were applied to either enamel or dentine as per manufacturer's instructions. In 40 specimens, the bonding agent was light cured immediately after the application (pre-cured). The other 40 specimens were not light cured until the composite resin application (co-cured). Resin composite cylinders were made incrementally using acrylic moulds over the adhesives and light cured. Specimens were stored in deionised water for 24 hours at room temperature. Shear bond strength was measured using an Instron universal testing machine (in MPa) and was analysed with Student's unpaired t test. Light curing the adhesive separately produced significantly higher bond strengths to primary dentine than co-curing (padhesive separately did not produce significantly different bond strengths to primary enamel (p>0.05). Curing sequence had no significant effect on shear bond strength of adhesives on the primary enamel. Pre-curing adhesives before curing composite resins produced greater shear bond strength to primary dentine.

  8. Micromorphological effect of calcium phosphate coating on compatibility of magnesium alloy with osteoblast

    Science.gov (United States)

    Hiromoto, Sachiko; Yamazaki, Tomohiko

    2017-12-01

    Octacalcium phosphate (OCP) and hydroxyapatite (HAp) coatings were developed to control the degradation speed and to improve the biocompatibility of biodegradable magnesium alloys. Osteoblast MG-63 was cultured directly on OCP- and HAp-coated Mg-3Al-1Zn (wt%, AZ31) alloy (OCP- and HAp-AZ31) to evaluate cell compatibility. Cell proliferation was remarkably improved with OCP and HAp coatings which reduced the corrosion and prevented the H2O2 generation on Mg alloy substrate. OCP-AZ31 showed sparse distribution of living cell colonies and dead cells. HAp-AZ31 showed dense and homogeneous distribution of living cells, with dead cells localized over and around corrosion pits, some of which were formed underneath the coating. These results demonstrated that cells were dead due to changes in the local environment, and it is necessary to evaluate the local biocompatibility of magnesium alloys. Cell density on HAp-AZ31 was higher than that on OCP-AZ31 although there was not a significant difference in the amount of Mg ions released in medium between OCP- and HAp-AZ31. The outer layer of OCP and HAp coatings consisted of plate-like crystal with a thickness of around 0.1 μm and rod-like crystals with a diameter of around 0.1 μm, respectively, which grew from a continuous inner layer. Osteoblasts formed focal contacts on the tips of plate-like OCP and rod-like HAp crystals, with heights of 2-5 μm. The spacing between OCP tips of 0.8-1.1 μm was wider than that between HAp tips of 0.2-0.3 μm. These results demonstrated that cell proliferation depended on the micromorphology of the coatings which governed spacing of focal contacts. Consequently, HAp coating is suitable for improving cell compatibility and bone-forming ability of the Mg alloy.

  9. Micro-morphologic changes around biophysically-stimulated titanium implants in ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Chang Ting-Ling

    2007-07-01

    Full Text Available Abstract Background Osteoporosis may present a risk factor in achievement of osseointegration because of its impact on bone remodeling properties of skeletal phsiology. The purpose of this study was to evaluate micro-morphological changes in bone around titanium implants exposed to mechanical and electrical-energy in osteoporotic rats. Methods Fifteen 12-week old sprague-dowley rats were ovariectomized to develop osteoporosis. After 8 weeks of healing period, two titanium implants were bilaterally placed in the proximal metaphyses of tibia. The animals were randomly divided into a control group and biophysically-stimulated two test groups with five animals in each group. In the first test group, a pulsed electromagnetic field (PEMF stimulation was administrated at a 0.2 mT 4 h/day, whereas the second group received low-magnitude high-frequency mechanical vibration (MECHVIB at 50 Hz 14 min/day. Following completion of two week treatment period, all animals were sacrificed. Bone sites including implants were sectioned, removed en bloc and analyzed using a microCT unit. Relative bone volume and bone micro-structural parameters were evaluated for 144 μm wide peri-implant volume of interest (VOI. Results Mean relative bone volume in the peri-implant VOI around implants PEMF and MECHVIB was significantly higher than of those in control (P P > .05 while the difference in trabecular-number among test and control groups was significant in all VOIs (P Conclusion Biophysical stimulation remarkably enhances bone volume around titanium implants placed in osteoporotic rats. Low-magnitude high-frequency MECHVIB is more effective than PEMF on bone healing in terms of relative bone volume.

  10. Influence of the incidence angle on the morphology of enamel and dentin under Er:YAG laser irradiation

    International Nuclear Information System (INIS)

    Junqueira Junior, Duilio Naves

    2002-01-01

    The purpose of this study is to make an in vitro evaluation, using scanning electron microscopy, of the influence of the laser beam irradiation angle on the enamel and dentin morphology. These tissues were both irradiated by Er:YAG Laser, with the same energy parameter. Twenty-four incisive bovine teeth were used, separated in eight groups, four of enamel, and four of dentin, with three specimens in each group. Each specimen was submitted to three laser applications, varying the incidence angle, between the laser and the tooth surface, at 90, 50 and 20 degrees. The applied frequency was 2 Hz, with 20 pulses in each application. The KaVo Key Laser 3 was employed, wavelength at 2940 nm, adjustable energy from 40 to 600 mJ and repetition rate from 1 to 25 Hz. The groups were distributed according to the energy parameter as follows - enamel: 250 mJ; 300 mJ; 350 mJ and 400 mJ; dentin: 200 mJ; 250 mJ; 300 mJ and 350 mJ. The results evidenced the Laser incidence angle importance; it is an essential parameter in the protocol of utilization and it should not be disregarded. The observations of this study allow to conclude that the Laser incidence angle has direct influence on the morphological aspect of the alterations produced in enamel and dentin. (author)

  11. Detection of dentin antigenic fractions by salivary immunoglobulin G ...

    African Journals Online (AJOL)

    SAM

    2014-05-28

    May 28, 2014 ... non-collagenous proteins (NCP) and signaling molecules ... periodontal tissues and by signals and cytokines production ... Dentin extract was stored at -80°C until use. .... An effective mechanism to prevent self-reactivity is the.

  12. Comparison of removed dentin thickness with hand and rotary instruments

    Science.gov (United States)

    Shahriari, Shahriar; Abedi, Hasan; Hashemi, Mahdi; Jalalzadeh, Seyed Mohsen

    2009-01-01

    INTRODUCTION: The aim of this study was to evaluate the amount of dentine removed after canal preparation using stainless steel (SS) hand instruments or rotary ProFile instruments. MATERIALS AND METHODS: Thirty-six extracted human teeth with root canal curvatures less than 30º were embedded in clear polyester resin. The roots were cut horizontally at apical 2, 4 and 7 mm. Dentin thickness was measured at each section and the sections were accurately reassembled using a muffle. Root canals were randomly prepared by SS hand instruments or rotary ProFile instruments. Root sections were again separated, and the remaining dentin thickness was measured. Mann-Whitney U and t tests were performed for analytic comparison of the results. RESULTS: The thickness of removed dentin was significantly different between the two used methods (Pinstrumentation group (Protary instrumentation prepares root canals with a greater conservation of tooth structure. PMID:23940489

  13. Role of Alcohol on the Fracture Resistance of Dentin

    Energy Technology Data Exchange (ETDEWEB)

    Nalla, Ravi K.; Kinney, John H.; Tomsia, Antoni P.; Ritchie,Robert O.

    2006-05-01

    Healthy dentin, the mineralized tissue that makes up the bulk of the tooth, is naturally hydrated in vivo; however, it is known that various chemical reagents including acetone and ethanol can induce dehydration and thereby affect its properties. Here, we seek to investigate this in light of the effect alcohol can have on the mechanical properties of dentin, specifically by measuring the stiffness, strength and toughness of dentin in simulated body fluid and scotch whisky. Results indicate that chemical dehydration induced by the whisky has a significant beneficial effect on the elastic modulus, strength and fracture toughness of dentin. Although this makes teeth more resistant to fracture, the change in properties is fully reversible upon rehydration. This effect is considered to be associated with increased cross-linking of the collagen molecules from intermolecular hydrogen-bonding where water is replaced with weaker hydrogen-bond forming solvents such as alcohol.

  14. Determination of some variables of human dentin for dosimetric purposes

    International Nuclear Information System (INIS)

    Peres, C.

    1990-01-01

    The initial objective of this work is to determine the atomic composition of human dentin, using various techniques of measurements such as X-Ray fluorescence, atomic absorption, spectrophotometry, volumetric analysis, chemistry, colorimetry and thermogravimetry. With the values of the effective atomic number Z bar dependent of the quality of the ionizing radiation, one can find the kind of material that can be used for a phantom equivalent to dentin. (author)

  15. "Interred with their bones" - linking soil micromorphology and chemistry to unlock the hidden archive of archaeological human burials

    Science.gov (United States)

    Brothwell, Don; Usai, Maria-Raimonda; Keely, Brendan; Pickering, Matt; Wilson, Clare

    2010-05-01

    "Interred with their bones" Acronym: InterArChive - an ERC-funded project *** " Friends, Romans, countrymen, lend me your ears; " I come to bury Caesar, not to praise him. " The evil that men do lives after them; " The good is oft 'interred with their bones'; " So let it be with Caesar. William Shakespeare, Julius Caesar, Act III, Scene 2. *** Background The state of decay within soils in archaeological graves is often such that degradable objects are not preserved in a condition that can be visually recognised. However, microscopic soil features, inorganic element distributions and organic residues can be measured. Thus, archaeological burial soils have the potential to reveal signatures of decay; pre-burial treatment; presence and nature of associated clothing and perishable artefacts; diet of the individual; cause of death; evidence of morbidity and drug-use. Aims • To develop and test a multidisciplinary approach linking soil micromorphology and chemistry to recover environmental and cultural information; • Revealing the hidden archaeological archive within the burial soil • Developing soil sampling and analysis recommendations for archaeological human burials Methods 1: Sampling and soil field description from archaeological sites contrasting in soil, geology, age, and culture and from experimental piglet burials 2: Microscopic/micromorphological analysis (micro-scale observations) of remains and features in burial soils. We will establish the order of occurrence, spatial patterns, displacement, mode of formation and decay of micromorphological features including exotic components, parasites, hair and remnants of footwear and clothing [cf. pilot study of soils from Yemen]; microfabrics and textural pedofeatures, also to facilitate resolution of body decay products from other accumulations. 3: Microprobe analysis (nano-scale) will generate elemental maps of soil thin sections, allowing identification of features with distinct chemical signatures

  16. Application of magnetic, geochemical and micro-morphological methods in environmental studies of urban pollution generated by road traffic

    Energy Technology Data Exchange (ETDEWEB)

    Bucko, M.

    2012-11-01

    Road traffic is at present one of the major sources of environmental pollution in urban areas. Magnetic particles, heavy metals and other compounds generated by traffic can greatly affect ambient air quality and have direct implications for human health. The general aim of this research was to identify and characterize magnetic vehicle-derived particulates using magnetic, geochemical and micro-morphological methods. A combination of three different methods was used to discriminate sources of particular anthropogenic particles. Special emphasis was placed on the application of various collectors (roadside soil, snow, lichens and moss bags) to monitor spatial and temporal distribution of traffic pollution on roadsides. The spatial distribution of magnetic parameters of road dust accumulated in roadside soil, snow, lichens and moss bags indicates that the highest concentration of magnetic particles is in the sampling points situated closest to the road edge. The concentration of magnetic particles decreases with increasing distance from the road indicating vehicle traffic as a major source of emission. Significant differences in horizontal distribution of magnetic susceptibility were observed between soil and snow. Magnetic particles derived from road traffic deposit on soil within a few meters from the road, but on snow up to 60 m from the road. The values of magnetic susceptibility of road dust deposited near busy urban motorway are significantly higher than in the case of low traffic road. These differences are attributed to traffic volume, which is 30 times higher on motorway than on local road. Moss bags placed at the edge of urban parks situated near major roads show higher values of magnetic susceptibility than moss bags from parks located near minor routes. Enhanced concentrations of heavy metals (e.g. Fe, Mn, Zn, Cu, Cr, Ni and Co) were observed in the studied samples. This may be associated with specific sources of vehicle emissions (e.g. exhaust and non

  17. Regeneration of dental pulp/dentine complex with a three-dimensional and scaffold-free stem-cell sheet-derived pellet.

    Science.gov (United States)

    Na, Sijia; Zhang, Hao; Huang, Fang; Wang, Weiqi; Ding, Yin; Li, Dechao; Jin, Yan

    2016-03-01

    Dental pulp/dentine complex regeneration is indispensable to the construction of biotissue-engineered tooth roots and represents a promising approach to therapy for irreversible pulpitis. We used a tissue-engineering method based on odontogenic stem cells to design a three-dimensional (3D) and scaffold-free stem-cell sheet-derived pellet (CSDP) with the necessary physical and biological properties. Stem cells were isolated and identified and stem cells from root apical papilla (SCAPs)-based CSDPs were then fabricated and examined. Compact cell aggregates containing a high proportion of extracellular matrix (ECM) components were observed, and the CSDP culture time was prolonged. The expression of alkaline phosphatase (ALP), dentine sialoprotein (DSPP), bone sialoprotein (BSP) and runt-related gene 2 (RUNX2) mRNA was higher in CSDPs than in cell sheets (CSs), indicating that CSDPs have greater odonto/osteogenic potential. To further investigate this hypothesis, CSDPs and CSs were inserted into human treated dentine matrix fragments (hTDMFs) and transplanted into the subcutaneous space in the backs of immunodeficient mice, where they were cultured in vivo for 6 weeks. The root space with CSDPs was filled entirely with a dental pulp-like tissue with well-established vascularity, and a continuous layer of dentine-like tissue was deposited onto the existing dentine. A layer of odontoblast-like cells was found to express DSPP, ALP and BSP, and human mitochondria lined the surface of the newly formed dentine-like tissue. These results clearly indicate that SCAP-CSDPs with a mount of endogenous ECM have a strong capacity to form a heterotopic dental pulp/dentine complex in empty root canals; this method can be used in the fabrication of bioengineered dental roots and also provides an alternative treatment approach for pulp disease. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Laboratory evaluation of the effect of unfilled resin after the use of self-etch and total-etch dentin adhesives on the Shear Bond Strength of composite to dentin.

    Science.gov (United States)

    Nasseri, Ehsan Baradaran; Majidinia, Sara; Sharbaf, Davood Aghasizadeh

    2017-05-01

    Based on the frequent application of composite resins as tooth-colored fillings, this method is considered a viable alternative to dental amalgam. However, this method has the low bond strength of the composite to dentin. To solve this issue, various dental adhesive systems with different characteristics have been developed by dentistry experts. To assess the effect of an additional layer of unfilled resin in self-etch and total-etch dentin adhesives on the shear bond strength (SBS) of composite to dentin. Moreover, we assessed the effects of sample storage in artificial saliva on the SBS of composite to dentin. Methods: This experimental study was conducted on 160 freshly extracted human first or second premolar teeth, which were randomly divided into 16 groups. The teeth were prepared from Mashhad University of Medical Sciences, Mashhad, Iran (2008-2009). Scotchbond Multi-purpose (SBMP), single bond (SB), Clearfil SE Bond, and Clearfil S3 Bond were applied to dentin surface with or without the placement of hydrophobic resin (Margin Bond) in accordance with the instructions of the manufacturers. To expose the coronal dentin, the teeth were abraded with 600 grit SiC paper. Immediately after restoration, half of the samples were tested in terms of SBS, while the other samples were evaluated in terms of SBS after three months of storage in artificial saliva. SBS rates of dental composites evaluated by universal testing machine and samples were studied by optical stereomicroscopy to verify the failure type. Data analysis was performed in SPSS V.16 using Kolmogorov-Smirnov test, independent-samples t-test, ANOVA, and Duncan's logistic regression test. In this study, a significant reduction was observed in the SBS rates of SB and S3 bond adhesive systems after storage with and without hydrophobic resin (p>0.000). Without storage in normal saline, a significant increase was observed in the SBS rate of the SE bond (p=0.013). In addition, SBS rate of SBMP significantly

  19. A high-frequency in vitro multiplication, micromorphological studies and ex vitro rooting of Cadaba fruticosa (L.) Druce (Bahuguni): a multipurpose endangered medicinal shrub.

    Science.gov (United States)

    Lodha, Deepika; Patel, Ashok Kumar; Shekhawat, N S

    2015-07-01

    An efficient and reproducible in vitro propagation protocol has been established for Cadaba fruticosa (L.) Druce. Surface-sterilized nodal stem segments of mature plant were used as explants for culture establishment. Multiple shoots were optimally differentiated from the nodal stem explants through bud breaking on Murashige and Skoog (1962) medium containing 3.0 mg l(-1) benzyladenine (BA). The effect of different plant growth regulators and minerals were studied on different stages of micropropagation procedure (i.e., explant establishment, shoot multiplication/growth and ex vitro rooting). Additionally, for enhancing shoot multiplication during subculture, MS medium was modified (MMS) with higher levels of magnesium, potassium and sulphate ions. Out of these, MMS3 medium containing 0.25 mg l(-1) each of BA and Kin (N6-furfuryladenine), with 0.1 mg l(-1) NAA (α-naphthalene acetic acid) was found the best for shoot multiplication (42.45 ± 3.82 per culture vessel). The in vitro regenerated shoots were rooted under ex vitro conditions on treating the shoot base with 500 mg l(-1) of IBA (indole-3 butyric acid) for 3 min on sterile Soilrite®. The ex vitro rooted plants were hardened in the greenhouse and transferred to the field with ≈85 % survival rate. There were not any visual differences between wild and micropropagated plants in the field, although the later underwent significant changes during acclimatization. Micromorphological changes on leaf surface characters from in vitro to acclimatized plantlets were studied in terms of development of glandular trichomes, changes in vein spacing and vein structure in order to understand the nature of plant responses towards environmental conditions. The method developed and defined can be applied for commercial cultivation, which may be important for extraction of bioactive compounds and may facilitate conservation of this multipurpose endangered medicinal shrub.

  20. In vitro evaluation of influence of salivary contamination on the dentin bond strength of one-bottle adhesive systems

    Directory of Open Access Journals (Sweden)

    Nujella B.P Suryakumari

    2011-01-01

    Full Text Available Aim: To evaluate the effect of salivary contamination on the bond strength of one-bottle adhesive systems - (the V generation at various stages during the bonding procedure and to investigate the effect of the contaminant removing treatments on the recovery of bond strengths. Materials and Methods: In this study the V generation one-bottle system - (Adper Single Bond was tested. Fifty caries-free human molars with flat dentin surfaces were randomly divided into five groups of ten teeth each: Group I had 15 second etching with 35% Ortho Phosphoric acid, 15 second rinse and blot dried (Uncontaminated; Group II contaminated and blot dried; Group III contaminated and completely dried; Group IV contaminated, washed, blot dried; Group V contaminated, retched washed, and blot dried. The bonding agent was applied and resin composite (Z-100 3M ESPE was bonded to the treated surfaces using the Teflon mold. The specimens in each group were then subjected to shear bond strength testing in an Instron Universal testing machine at a crosshead speed of 1 mm / minute and the data were subjected to one way ANOVA for comparison among the groups (P<0.05. Results: There was a significant difference between the group that was dried with strong oil-free air after contamination (Group III and the other groups. When the etched surface was contaminated by saliva, there was no statistical difference between the just blot dry, wash, or the re-etching groups (Groups II, IV, V if the dentin surface was kept wet before priming. When the etched dentin surface was dried (Group III the shear bond strength decreased considerably. Conclusion: The bond strengths to the tooth structure of the recent dentin bonding agents are less sensitive to common forms of contamination than assumed. Re-etching without additional mechanical preparation is sufficient to provide or achieve the expected bond strength.

  1. 3D variations in human crown dentin tubule orientation: a phase-contrast microtomography study.

    Science.gov (United States)

    Zaslansky, Paul; Zabler, Simon; Fratzl, Peter

    2010-01-01

    Tubules dominate the microstructure of dentin, and in crowns of human teeth they are surrounded by thick mineralized peritubular cuffs of high stiffness. Here we examine the three-dimensional (3D) arrangement of tubules in relation to enamel on the buccal and lingual aspects of intact premolars and molars. Specifically we investigate the angular orientation of tubules relative to the plane of the junction of dentin with enamel (DEJ) by means of wet, non-destructive and high-resolution phase-contrast (coherent) tomography. Enamel capped dentin samples (n=16), cut from the buccal and lingual surfaces of upper and lower premolar and molar teeth, were imaged in water by high-resolution synchrotron-based phase-contrast X-ray radiography. Reconstructed 3D virtual images were co-aligned with respect to the DEJ plane. The average tubule orientation was determined at increasing distances from the DEJ, based on integrated projections onto orthogonal virtual planes. The angle and curl of the tubules were determined every 100 microm to a depth of 1.4mm beneath the DEJ. Most tubules do not extend at right angles from the DEJ. Even when they do, tubules always change their orientations substantially within the first half-millimeter zone beneath the DEJ, both on the buccal and lingual aspects of premolar and molar teeth. Tubules also tend to curl and twist within this zone. Student t-tests indicate that lower teeth seem to have greater tilts in the tubule orientations relative to the DEJ normal with an average angle of 42 degrees (+/-2.0 degrees), whereas upper teeth exhibit a smaller change of orientation, with an average of 32 degrees (+/-2.1 degrees). Tubules are a central characteristic of dentin, with important implications on how it is arranged and what the properties are. Knowing about the path that tubules follow is important for various reasons, ranging form improving control over restorative procedures to understanding or simulating the mechanical properties of teeth

  2. Effect of high energy X-ray irradiation on the nano-mechanical properties of human enamel and dentine

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Xue; Zhang, Jing Yang; Cheng, Iek Ka [State Key Laboratory of Oral Diseases, Sichuan University, Chengdu (China); Li, Ji Yao, E-mail: jiyao_li@aliyun.com [West China School of Stomatology, Sichuan University, Chengdu (China)

    2016-05-01

    Radiotherapy for malignancies in the head and neck can cause common complications that can result in tooth damage that are also known as radiation caries. The aim of this study was to examine damage to the surface topography and calculate changes in friction behavior and the nano-mechanical properties (elastic modulus, nano hardness and friction coefficient) of enamel and dentine from extracted human third molars caused by exposure to radiation. Enamel and dentine samples from 50 human third molars were randomly assigned to four test groups or a control group. The test groups were exposed to high energy X-rays at 2 Gy/day, 5 days/week for 5 days (10 Gy group), 15 days (30 Gy group), 25 days (50 Gy group), 35 days (70 Gy group); the control group was not exposed. The nano hardness, elastic modulus, and friction coefficient were analyzed using a Hysitron Triboindenter. The nano-mechanical properties of both enamel and dentine showed significant dose-response relationships. The nano hardness and elastic modulus were most variable between 30-50 Gy, while the friction coefficient was most variable between 0-10 Gy for dentine and 30-50 Gy for enamel. After exposure to X-rays, the fracture resistance of the teeth clearly decreased (rapidly increasing friction coefficient with increasing doses under the same load), and they were more fragile. These nano-mechanical changes in dental hard tissue may increase the susceptibility to caries. Radiotherapy caused nano-mechanical changes in dentine and enamel that were dose related. The key doses were 30-50 Gy and the key time points occurred during the 15{sup th}-25{sup th} days of treatment, which is when application of measures to prevent radiation caries should be considered. (author)

  3. Effect of root canal rinsing protocol on dentin bond strength of two resin cements using three different method of test.

    Science.gov (United States)

    Khoroushi, Maryam; Sheikhi, Mohammadreza; Khalilian-Gourtani, Amirhossein; Soleimani, Bahram

    2016-07-01

    Different studies have used different tests to evaluate bond strength of resin cements to root dentin. In this in vitrostudy, three different tests were used to evaluate the bond strength of two resin cements to root dentin using two root dentin irrigation protocols. Ninety-six intact single-rooted teeth were selected for this study. Forty-eight teeth, with a root length of 15mm, were randomly divided into two groups and irrigated with normal saline or 2.5% sodium hypochlorite solutions during root canal preparation, respectively. For each 12 specimens from each group, fiber post #1 was bonded using an etch-and-rinse (Duo-Link) and a self-adhesive (BisCem) resin cement, respectively. After incubation, two specimens were prepared for the push-out test from the middle thirds of the roots. In another 24 teeth, after two 1.5-mm sections were prepared from the middle thirds of the prepared roots, sections of the post were bonded in two subgroups with each of the cements mentioned above and the samples were prepared for the pull-out test. For shear test, the crowns of 48 teeth were cut away, the dentin surfaces were prepared, the two irrigation solutions were used, and the resin cements were bonded. Data collected from the three tests were evaluated by ANOVA, post-hoc Tukey and Weibull tests (α=0.05). There were significant differences in the mean bond strength values between the three bond strength tests (Pstrength in all tests (P>0.05). Under the limitations of the present study, the method of the test used had an effect on the recorded bond strength between the resin cement and root dentin. Cement type and irrigation protocol resulted in similar variations with all the tests. Push-out and shear tests exhibited more coherent results. Bond strength, endodontically treated tooth, fiber post, resin cement, sodium hypochlorite.

  4. Evaluation of bond strength of self-etching adhesives having different pH on primary and permanent teeth dentin.

    Science.gov (United States)

    Ozmen, Bilal; Koyuturk, Alp Erdin; Tokay, Ugur; Cortcu, Murat; Sari, Mustafa Erhan

    2015-10-16

    The purpose of this in vitro study was to evaluate the dentin shear bond strength of 4 self-etching adhesives having a different pH on primary and permanent teeth dentin. The occlusal enamel was removed from 60 freshly extracted third molar and 60 primary second molar human teeth, which were randomly separated into 4 groups (n = 15). Four adhesive systems were applied: G-Bond (GC Corporation, Tokyo, Japan, pH: 1.5), Futura Bond M (Voco, Cuxhaver, Germany, pH: 1.4), Adper Prompt L-Pop (3M/ESPE, St Paul, MN, USA, pH: 0.8), and Clearfil S(3) Bond (Kuraray Medical, Tokyo, Japan, pH: 2.7) according to the manufacturer's instructions. After the application of dentin bonding agents, a composite resin material (Z250 Restorative A2, 3M ESPE, St. Paul, MN, USA) for permanent teeth and a compomer resin material (Dyract Extra A2, Dentsply, Konstanz, Germany) for primary teeth was applied onto the prepared dentin surfaces. The data were obtained by using a universal test machine at a crosshead speed of 1 mm/min. The mean values were compared using Tukey's multiple comparison test. Although there was no difference between adhesives on the permanent teeth, Clearfil S3 adhesive showed higher bond (18.07 ± 0.58 MPa) (P>0.05). Lower bond strength values were obtained from primary teeth and especially G-Bond adhesive (9.36 ± 0.48 MPa) (Padhesives with different pH and solvent types can be used successfully for permanent teeth dentin but adhesives with low pH did not provide greater shear bond strength values.

  5. The Effect of Laser Irradiation on Shear Bond Strength of GI to Dentin After CPP-ACP Treatment

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    Moezizadeh

    2016-02-01

    Full Text Available Background Dentin sensitivity is one of the most important problems in dentistry. Enamel loss due to root exposure is serious issue and common exposure is one of the reasons for dentin hypersensitivity. There are different methods for solving this problem. One of the most conservative and least expensive methods is use of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP paste. Objectives The aim of this study was to evaluate shear bond strength of GIC to dentin, with or without laser, CPP-ACP paste and polyacrylic acid treatments. Materials and Methods Fifty sound human third molars were bisected in a mesiodistal direction using a diamond disk. Using 400, 600 and 800 grit silicon carbide paper, dentin surfaces were exposed. The teeth were divided into five groups. In groups A, B, D and H, CPP-ACP (GC tooth mousse Itabashi-Ku, Tokyo, Japan was applied for one hour the first day and repeated at the same time of day for a total of five days. In groups B, C, D and E, the specimens were subjected to laser for 10 seconds using Er, Cr: YSGG laser. In groups B, C, H and G, specimens were treated with 10% polyacrylic acid for 20 seconds. A plastic tube containing GI was positioned over the tooth. Samples were loaded in shear bond using a Universal Testing Machine (Zwick/Roell, Germany, at a 0.5 mm/minute crosshead speed. Results Despite the failing of groups A and D, group analysis showed that there were no significant differences between the groups. The predominant type of fracture in all groups was adhesive. Conclusions Application of CPP-ACP, without preconditioning with polyacrylic acid, can decrease shear bond strength. Laser irradiation has no effect on shear bond strength of GIC to dentin in this condition.

  6. Effect of Peracetic Acid as A Final Rinse on Push Out Bond Strength of Root Canal Sealers to Root Dentin.

    Science.gov (United States)

    Gaddala, Naresh; Veeramachineni, Chandrasekhar; Tummala, Muralidhar

    2015-05-01

    Smear layer which was formed during the instrumentation of root canals hinders the penetration of root canal sealers to root dentin and affect the bond strength of root canal sealers to root dentin. Final irrigant such as demineralizing agents are used to remove the inorganic portion of the smear layer. In the present study, peracetic acid used as a final rinse, to effect the bond strength of root canal sealers to root dentin. The purpose of the present study was to evaluate the efficacy of peracetic acid as a final irrigant on bond strength of root canal sealers to root dentin. Sixty six freshly extracted human single rooted mandibular premolars were used for this study. After decoronation the samples were instrumented with Protaper upto F3 and irrigated with 5.25% NaOcl. The teeth were then divided into three groups based on final irrigant used: Group-1(control group) Canals were irrigated with distilled water. Group-2: Canals were irrigated with peracetic acid. Group-3: Canals were irrigated with smear clear. Each group was further divided into three subgroups (n=30) based on the sealer used to obturate the canals. Subgroup-1: kerr, Subgroup-2: Apexit plus, Subgroup-3: AH PLUS. Each sealer was mixed and coated to master cone and placed in the canal. The bonding between sealer and dentin surface was evaluated using push out bond strength by universal testing machine. The mean bond strength values of each group were statistically evaluated using Two-way ANOVA followed by Tukey post-hoc test. Significant difference was found among the bond strength of the sealers. But, there is no statistically significant difference between the groups irrigated with peracetic acid and smear clear compared to control group. AH Plus showed highest bond strength irrespective of the final irrigant used. Peracetic acid when employed as final irrigant improved the bond strength of root canal sealers compared to control group but not statistically significant than smear clear.

  7. Bond Strength of Resin Composite to Dentin with Different Adhesive Systems: Influence of Relative Humidity and Application Time.

    Science.gov (United States)

    Amsler, Fabienne; Peutzfeldt, Anne; Lussi, Adrian; Flury, Simon

    2015-06-01

    To investigate the influence of relative humidity and application time on bond strength to dentin of different classes of adhesive systems. A total of 360 extracted human molars were ground to mid-coronal dentin. The dentin specimens were treated with one of six adhesive systems (Syntac Classic, OptiBond FL, Clearfil SE Bond, AdheSE, Xeno Select, or Scotchbond Universal), and resin composite (Filtek Z250) was applied to the treated dentin surface under four experimental conditions (45% relative humidity/application time according to manufacturers' instructions; 45% relative humidity/reduced application time; 85% relative humidity/application time according to manufacturers' instructions; 85% relative humidity/reduced application time). After storage (37°C, 100% humidity, 24 h), shear bond strength (SBS) was measured and data analyzed with nonparametric ANOVA followed by Kruskal-Wallis tests and Mann-Whitney U-tests with Bonferroni-Holm correction for multiple testing (level of significance: α = 0.05). Increased relative humidity and reduced application time had no effect on SBS for Clearfil SE Bond and Scotchbond Universal (p = 1.00). For Syntac Classic, OptiBond FL, AdheSE, and Xeno Select there was no effect on SBS of reduced application time of the adhesive system (p ≥ 0.403). However, increased relative humidity significantly reduced SBS for Syntac Classic, OptiBond FL, and Xeno Select irrespective of application time (p ≤ 0.003), whereas for AdheSE, increased relative humidity significantly reduced SBS at recommended application time only (p = 0.002). Generally, increased relative humidity had a detrimental effect on SBS to dentin, but reduced application time had no effect.

  8. Effect of high energy X-ray irradiation on the nano-mechanical properties of human enamel and dentine

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    Xue LIANG

    2016-01-01

    Full Text Available Abstract Radiotherapy for malignancies in the head and neck can cause common complications that can result in tooth damage that are also known as radiation caries. The aim of this study was to examine damage to the surface topography and calculate changes in friction behavior and the nano-mechanical properties (elastic modulus, nanohardness and friction coefficient of enamel and dentine from extracted human third molars caused by exposure to radiation. Enamel and dentine samples from 50 human third molars were randomly assigned to four test groups or a control group. The test groups were exposed to high energy X-rays at 2 Gy/day, 5 days/week for 5 days (10 Gy group, 15 days (30 Gy group, 25 days (50 Gy group, 35 days (70 Gy group; the control group was not exposed. The nanohardness, elastic modulus, and friction coefficient were analyzed using a Hysitron Triboindenter. The nano-mechanical properties of both enamel and dentine showed significant dose-response relationships. The nanohardness and elastic modulus were most variable between 30-50 Gy, while the friction coefficient was most variable between 0-10 Gy for dentine and 30-50 Gy for enamel. After exposure to X-rays, the fracture resistance of the teeth clearly decreased (rapidly increasing friction coefficient with increasing doses under the same load, and they were more fragile. These nano-mechanical changes in dental hard tissue may increase the susceptibility to caries. Radiotherapy caused nano-mechanical changes in dentine and enamel that were dose related. The key doses were 30-50 Gy and the key time points occurred during the 15th-25th days of treatment, which is when application of measures to prevent radiation caries should be considered.

  9. Effect of high energy X-ray irradiation on the nano-mechanical properties of human enamel and dentine

    International Nuclear Information System (INIS)

    Liang, Xue; Zhang, Jing Yang; Cheng, Iek Ka; Li, Ji Yao

    2016-01-01

    Radiotherapy for malignancies in the head and neck can cause common complications that can result in tooth damage that are also known as radiation caries. The aim of this study was to examine damage to the surface topography and calculate changes in friction behavior and the nano-mechanical properties (elastic modulus, nano hardness and friction coefficient) of enamel and dentine from extracted human third molars caused by exposure to radiation. Enamel and dentine samples from 50 human third molars were randomly assigned to four test groups or a control group. The test groups were exposed to high energy X-rays at 2 Gy/day, 5 days/week for 5 days (10 Gy group), 15 days (30 Gy group), 25 days (50 Gy group), 35 days (70 Gy group); the control group was not exposed. The nano hardness, elastic modulus, and friction coefficient were analyzed using a Hysitron Triboindenter. The nano-mechanical properties of both enamel and dentine showed significant dose-response relationships. The nano hardness and elastic modulus were most variable between 30-50 Gy, while the friction coefficient was most variable between 0-10 Gy for dentine and 30-50 Gy for enamel. After exposure to X-rays, the fracture resistance of the teeth clearly decreased (rapidly increasing friction coefficient with increasing doses under the same load), and they were more fragile. These nano-mechanical changes in dental hard tissue may increase the susceptibility to caries. Radiotherapy caused nano-mechanical changes in dentine and enamel that were dose related. The key doses were 30-50 Gy and the key time points occurred during the 15 th -25 th days of treatment, which is when application of measures to prevent radiation caries should be considered. (author)

  10. Evaluation of microhardness of residual dentin in primary molars following caries removal with conventional and chemomechanical techniques: An In vitro Study

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    A Shihab Anwar

    2017-01-01

    Full Text Available Background: Many patients consider removal of caries to be a very unpleasant experience. Removal of caries with conventional drill is considered traumatic mainly due to fear and anxiety of children and their parents. Minimally invasive dentistry adopts a philosophy that integrates prevention, remineralization, and minimal intervention for the placement and replacement of restorations, thus reaching the treatment objective using the least invasive surgical approach, with the removal of the minimal amount of healthy tissues. Chemomechanical caries removal (CMCR is a method for minimally invasive, gentle dentin caries removal based on biological principles which is an effective alternative to the traditional method. The present study was done to compare the microhardness of sound dentin before and after carious removal using a chemomechanical method and a conventional method. Materials and Methods: The present in vitro study was done on 28 proximal surfaces of fourteen extracted primary molars (with active caries on one proximal surface and sound side as control. The study was done to assess the Knoop microhardness of remaining dentinal surface after caries removal using a slow speed conventional bur and a chemomechanical method (Carie-Care™. Results and Conclusion: The rotary instrument group showed a consistent microhardness value with not much difference according to depth. The chemomechanical group showed a lesser microhardness value closer to the cavity floor than away from it. The microhardness values at all depths were significantly different for each treatment group with an increased value seen in the rotary group. The mean microhardness values of residual dentin in treated side were found to be insignificant when compared among each interval in each group. The microhardness of sound dentin had high significant difference from that of residual dentin in both the rotary group and the chemomechanical group.

  11. Assessment of Drying Characteristics and Texture in Relation with Micromorphological Traits of Carob (Ceratonia silliqua L. Pods and Seeds

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    Maja Benković

    2016-01-01

    Full Text Available Carob tree (Ceratonia siliqua L. is a perennial leguminous evergreen tree native to the coastal regions of the Mediterranean basin and is considered to be an important component of vegetation for economic and environmental reasons. Two constituents of the pod, pulp and seeds, can be used as feed or in food production. In this study, drying characteristics, texture and microstructure of carob pods were studied. Three different carob samples were prepared: whole carob pod, carob pod parts and carob seed. The drying experiments and the modelling showed that carob seeds had the highest drying rate, followed by pod parts and the whole, intact carob fruit. Texture studies showed that the maximum compression force depended on the area of the carob fruit on which compression tests were performed. The seeds showed the highest compression force, followed by the stem zone, the tip and the centre of the fruit. Differences in drying behaviour and texture of carob pods can successfully be interpreted by the micromorphology of the carob pods and seeds. Determining the drying rate, maximum compressive force and micromorphological traits is of great importance for further carob processing (e.g. milling, sieving, carob bean gum production or usage in food or feed products.

  12. Effect of salivary contamination and decontamination on bond strength of two one-step self-etching adhesives to dentin of primary and permanent teeth.

    Science.gov (United States)

    Santschi, Katharina; Peutzfeldt, Anne; Lussi, Adrian; Flury, Simon

    2015-02-01

    To evaluate the effects of human saliva contamination and two decontamination procedures at different stages of the bonding procedure on the bond strength of two one-step self-etching adhesives to primary and permanent dentin. Extracted human primary and permanent molars (210 of each) were ground to mid-coronal dentin. The dentin specimens were randomly divided into 7 groups (n = 15/group/molar type) for each adhesive (Xeno V+ and Scotchbond Universal): no saliva contamination (control); saliva contamination before or after light curing of the adhesives followed by air drying, rinsing with water spray/air drying, or by rinsing with water spray/air drying/reapplication of the adhesives. Resin composite (Filtek Z250) was applied on the treated dentin surfaces. The specimens were stored at 37°C and 100% humidity for 24 h. After storage, shear bond strength (SBS) was measured and data analyzed with nonparametric ANOVA followed by exact Wilcoxon rank sum tests. Xeno V+ generated significantly higher SBS than Scotchbond Universal when no saliva contamination occurred. Saliva contamination reduced SBS of Xeno V+, with the reduction being more pronounced when contamination occurred before light curing than after. In both situations, decontamination involving reapplication of the adhesive restored SBS. Saliva contamination had no significant effect on Scotchbond Universal. There were no differences in SBS between primary and permanent teeth. Rinsing with water and air drying followed by reapplication of the adhesive restored bond strength to saliva-contaminated dentin.

  13. Comparative study of analgesic effect of the infrared low-intensity laser and 33% sodium fluoride paste in the treatment of dentinal hypersensitivity

    International Nuclear Information System (INIS)

    Oliveira, Glen Anderson Maia de

    2003-01-01

    Different desensitizing agents have been used in the treatment of dentinal hypersensitivity, however, some presented treatments are still frustrating. The purpose of this study was to evaluate the analgesic effect of the low-intensity GaAlAs laser (λ= 830 nm) in the treatment of dentinal hypersensitivity after mechanical and thermal stimuli, and compared it with the 33% sodium fluoride paste. Thirty two teeth with dentinal hypersensitivity were selected and randomly divided into two groups. For the laser group, each tooth was irradiated by a dose of 6 J/cm 2 during two minutes and half on the buccal side. The paste group was treated with a NaF/kaolin/glycerin (33:33:33) paste by burnishing the sensitive surface during four minutes. The sensitivity degree was measured before the beginning of the experiment, 24 h, 48 h, 72 h, 120 h, 15 days and 30 days after the first application. The results indicate that the dentinal hypersensitivity significantly diminished for the paste group after dental explorer. Regarding to air-blast, no significant differences were observed between the groups. Both of them were effective in reducing pain of the dentine hypersensitive after 120 h. (author)

  14. The induction of dentin bridge-like structures by constructs of subcultured dental pulp-derived cells and porous HA/TCP in porcine teeth.

    Science.gov (United States)

    Ando, Yusuke; Honda, Masaki J; Ohshima, Hayato; Tonomura, Akiko; Ohara, Takayuki; Itaya, Toshimitsu; Kagami, Hideaki; Ueda, Minoru

    2009-02-01

    The purpose of this study was to investigate dentin-bridge formation in teeth following the transplantation of dental pulp-derived cells seeded on hydroxyapatite/tricalcium phosphate (HA/TCP) scaffolds. The dental pulp tissues were removed from the extracted first molar teeth of miniature pigs and single cell populations were subcultured. Second-passage cells that had alkaline phosphatase activity were combined with scaffolds. Cell-scaffold constructs were placed in contact with the exposed pulp tissue. The dimensions of the exposed pulp site were approximately 1-2.5 mm in diameter and 2-3 mm in depth from the tooth surface. After placing the constructs, the tooth was restored with composite resin. Six weeks after transplantation, hard tissue formation was observed on the pulp tissue in histology. Dentinal tubule-like structures were observed in most of the hard tissue generated, and columnar cells, which showed positive immunoreactions with dentin sialoprotein (DSP) and heat shock protein (HSP)-25, were aligned beneath the hard tissues. When only scaffolds were placed on the pulp tissues, particles of hard tissue were formed, however dentinal tubule-like structures and odontoblasts were not observed despite the formation of hard tissue. In conclusion, the implantation of dental pulp constructs into pulp exposed stimulates the formation of calcified dentin-like structures.

  15. Variation on Molecular Structure, Crystallinity, and Optical Properties of Dentin Due to Nd:YAG Laser and Fluoride Aimed at Tooth Erosion Prevention

    Science.gov (United States)

    Freitas, Anderson Z.; Bachmann, Luciano; Benetti, Carolina; Ana, Patricia A.

    2018-01-01

    This in vitro study evaluated the compositional, crystalline, and morphological effects promoted by Nd:YAG laser on root dentin, and verified the effects of laser and topical acidulated phosphate fluoride application (APF-gel) on dentin erosion. 180 bovine dentin slabs were randomized into 4 groups (n = 45): G1–untreated, G2–APF-gel (1.23% F−, 4 min), G3–Nd:YAG (1064 nm, 84.9 J/cm2, 10 Hz), and G4–APF-gel application followed by Nd:YAG laser irradiation. The compositional, crystalline, and morphological effects promoted by treatments were investigated on five samples of each experimental group. The other samples were submitted to a 5-day, 10-day, or 15-day erosive and abrasive demineralization and remineralization cycling in order to create erosion lesions. The area and depth of lesions, as well as the optical attenuation coefficient, were assessed, and all data were statistically analysed (p laser promoted the reduction of carbonate, the formation of tetracalcium phosphate, as well as the melting and recrystallization of the dentin surface. Laser significantly decreased the area and depth of erosion lesions and altered the optical attenuation coefficient when compared to untreated and APF-gel groups, but the association of APF-gel and laser did not promote an additional effect. Nd:YAG laser irradiation can be a promissory treatment to prevent dentin erosion and the abrasion process. PMID:29389868

  16. Composite Replacement of Amalgam Restoration Versus Freshly Cut Dentin: An In Vitro Microleakage Comparison.

    Science.gov (United States)

    Redwan, H; Bardwell, D N; Ali, A; Finkelman, M; Khayat, S; Weber, H-P

    2016-01-01

    The aim of this study was to evaluate the microleakage of the composite restorations when bonded to tooth structure previously restored with amalgam material compared with that of freshly cut dentin. Thirty intact, extracted intact human molars were mounted in autopolymerizing acrylic resin. Class II box preparations were prepared on the occluso-proximal surfaces of each tooth (4-mm bucco-lingual width and 2-mm mesio-distal depth) with the gingival cavosurface margin 1 mm above the CEJ. Each cavity was then restored using high copper amalgam restoration (Disperalloy, Dentsply) and then thermocycled for 10,000 thermal cycles. Twenty-five of the amalgam restorations were then carefully removed and replaced with Filtek Supreme Ultra Universal (3M ESPE); the remaining five were used for scanning electron microscopy and energy dispersive x-ray spectroscopy analysis. A preparation of the same dimensions was performed on the opposite surface of the tooth and restored with composite resin and thermocycled for 5000 thermal cycles. Twenty samples were randomly selected for dye penetration testing using silver nitrate staining to detect the microleakage. The specimens were analyzed with a stereomicroscope at a magnification of 20×. All of the measurements were done in micrometers; two readings were taken for each cavity at the occlusal and proximal margins. Two measurements were taken using a 0-3 scale and the percentage measurements. Corrosion products were not detected in either group (fresh cut dentin and teeth previously restored with amalgam). No statistically significant difference was found between the microleakage of the two groups using a 0-3 scale at the occlusal margins (McNemar test, p=0.727) or proximal margins (Wilcoxon signed-rank test, p=0.174). No significance difference was found between the two groups using the percentage measurements and a Wilcoxon signed-rank test at either the occlusal (p=0.675) or proximal (p=0.513) margins. However, marginal

  17. Micromorphological investigation on ring road sediments of the Early Bronze Age site Tell Chuera, Syria

    Science.gov (United States)

    Fritzsch, Dagmar; Thiemeyer, Heinrich

    2010-05-01

    Tell Chuera is an Early Bronze Age settlement mount in NE-Syria close to the Turkish border. With a diameter of almost 1 km and a height of 18 m it is one of the biggest tells in the region between the rivers Balikh and Khabur. In 1958 the structures of the city wall was known first by Orthmann (1990). This city wall was built of air-dried mud bricks. The age of the founding of this construction is not yet clear. The earliest pottery from the place is dated around 2500 BC to 2350 BC. Inside the fortification a road was detected, which was first excavated by Novak (1995). We took sediment monoliths in 2004 from a new trench, which shows the same situation of the road. A geomagnetic prospection, that included the whole site, suggests that the road was part of the planned extension of the lower town and serves as a circular road (Meyer, in prep.). The micromorphological investigation focussed on the question, how the road was used. Did animals have had access to the town? The thin sections show different indications of the anthropogenic influence. In all samples pseudomorphs after straw are visible. In many parts ash, charred wood fragments, bone fragments, melted material and fragments of basalt and flint were observable, too. These materials are typical for sediments in streets (cf. Goldberg & Macphail, 2006). In some parts of the thin sections faecal spherulites and dung remains with faecal spherulites give an idea that ruminants used the road as well as men. Trampling structures support this assumption. Moreover, leaching of calcite, its redeposition in mottles, pseudomycels and concretions, hydromorphic stains and the translocation of silt indicate postdepositional pedogenic processes. Literature Goldberg, P., & Macphail, R. I. (2006). Practical and theoretical geoarchaeology: UK Blackwell Publishing. Meyer, J.-W. (in prep.). Überlegungen zur Siedlungsstruktur - eine erste Analyse der Ergebnisse der geomagnetischen Prospektion. In J.-W. Meyer (Ed.), Ausgrabungen

  18. Hipótesis actuales relacionadas con la sensibilidad dentinal

    Directory of Open Access Journals (Sweden)

    Andrés Pérez Ruiz

    1999-08-01

    Full Text Available Se hace una revisión sobre las hipótesis actuales concernientes a la sensibilidad dentinal, centrando el análisis en las teorías acerca de la presencia de nervios en la dentina, la transmisión del impulso nervioso mediante el odontoblasto y el movimiento de fluidos dentro de la dentina. Por ser la explicación de la sensibilidad de la dentina uno de los más complejos problemas de la fisiología y la histología del diente, se exponen los hechos morfológicos y funcionales que apoyan la validez de los mecanismos mencionados. Se concluye que aunque la teoría hidrodinámica tiene una sólida base experimental y es la de mayor aceptación en la actualidad, pudieran estar involucrados en la génesis del dolor dentinal más de una de estas explicaciones probables.A review of the present hypotheses of dentinal sensitivity was carried out. The analysis was centered on the theories of the existance of nerves in dentin, the transfer of nervous impulse through odontoblast and the fluid flow in the dentin. Since the explanation of dentin sensitivity is one of the most complex problems of dental physiology and histology; the morphological and functional aspects that support the validity of the mentioned mechanisms are stated. It is concluded that although the hydrodynamic theory has a sound experimental basis and is widely accepted at present, more than one of these likely theories could be involved in the genesis of dentinal pain.

  19. Tensile bond strength of indirect composites luted with three new self-adhesive resin cements to dentin

    Directory of Open Access Journals (Sweden)

    Cafer Türkmen

    2011-08-01

    Full Text Available OBJECTIVE: The aims of this study were to evaluate the tensile bond strengths between indirect composites and dentin of 3 recently developed self-adhesive resin cements and to determine mode of failure by SEM. MATERIAL AND METHODS: Exposed dentin surfaces of 70 mandibular third molars were used. Teeth were randomly divided into 7 groups: Group 1 (control group: direct composite resin restoration (Alert with etch-and-rinse adhesive system (Bond 1 primer/adhesive, Group 2: indirect composite restoration (Estenia luted with a resin cement (Cement-It combined with the same etch-and-rinse adhesive, Group 3: direct composite resin restoration with self-etch adhesive system (Nano-Bond, Group 4: indirect composite restoration luted with the resin cement combined with the same self-etch adhesive, Groups 5-7: indirect composite restoration luted with self-adhesive resin cements (RelyX Unicem, Maxcem, and Embrace WetBond, respectively onto the non-pretreated dentin surfaces. Tensile bond strengths of groups were tested with a universal testing machine at a constant speed of 1 mm/min using a 50 kgf load cell. Results were statistically analyzed by the Student's t-test. The failure modes of all groups were also evaluated. RESULTS: The indirect composite restorations luted with the self-adhesive resin cements (groups 5-7 showed better results compared to the other groups (p0.05. The surfaces of all debonded specimens showed evidence of both adhesive and cohesive failure. CONCLUSION: The new universal self-adhesive resins may be considered an alternative for luting indirect composite restorations onto non-pretreated dentin surfaces.

  20. Evaluation of bond strength of silorane and methacrylate based restorative systems to dentin using different cavity models

    Directory of Open Access Journals (Sweden)

    Stephano Zerlottini Isaac

    2013-09-01

    Full Text Available OBJECTIVE: The aim of this in vitro study was to evaluate the microtensile bond strength (µTBS to dentin of two different restorative systems: silorane-based (P90, and methacrylate-based (P60, using two cavity models. MATERIAL AND METHODS: Occlusal enamel of 40 human third molars was removed to expose flat dentin surface. Class I cavities with 4 mm mesial-distal width, 3 mm buccal-lingual width and 3 mm depth (C-factor=4.5 were prepared in 20 teeth, which were divided into two groups (n=10 restored with P60 and P90, bulk-filled after dentin treatment according to manufacturer's instructions. Flat buccal dentin surfaces were prepared in the 20 remaining teeth (C-factor=0.2 and restored with resin blocks measuring 4x3x3 mm using the two restorative systems (n=10. The teeth were sectioned into samples with area between 0.85 and 1.25 mm2 that were submitted to µTBS testing, using a universal testing machine (EMIC at speed of 0.5 mm/min. Fractured specimens were analyzed under stereomicroscope and categorized according to fracture pattern. Data were analyzed using ANOVA and Tukey Kramer tests. RESULTS: For flat surfaces, P60 obtained higher bond strength values compared with P90. However, for Class I cavities, P60 showed significant reduction in bond strength (p0.05, or between Class I Cavity and Flat Surface group, considering P90 restorative system (p>0.05. Regarding fracture pattern, there was no statistical difference among groups (p=0.0713 and 56.3% of the fractures were adhesive. CONCLUSION: It was concluded that methacrylate-based composite µTBS was influenced by cavity models, and the use of silorane-based composite led to similar bond strength values compared to the methacrylate-based composite in cavities with high C-factor.

  1. DEMINERALIZATION OF HUMAN DENTIN COMPARED WITH ENAMEL IN A PH-CYCLING APPARATUS WITH A CONSTANT COMPOSITION DURING DE-MINERALIZATION AND REMINERALIZATION PERIODS

    NARCIS (Netherlands)

    HERKSTROTER, FM; WITJES, M; ARENDS, J

    1991-01-01

    A comparison was made between the demineralization of enamel and dentine with and without abraded surfaces. This was done in a pH-cycling experiment for different demineralization/remineralization ratios - in the range from 1:1 to 1:4 - and for different fluoride additions (up to 2 ppm) in solution.

  2. Innovative Approaches to Regenerate Enamel and Dentin

    Directory of Open Access Journals (Sweden)

    Xanthippi Chatzistavrou

    2012-01-01

    Full Text Available The process of tooth mineralization and the role of molecular control of cellular behavior during embryonic tooth development have attracted much attention the last few years. The knowledge gained from the research in these fields has improved the general understanding about the formation of dental tissues and the entire tooth and set the basis for teeth regeneration. Tissue engineering using scaffold and cell aggregate methods has been considered to produce bioengineered dental tissues, while dental stem/progenitor cells, which can differentiate into dental cell lineages, have been also introduced into the field of tooth mineralization and regeneration. Some of the main strategies for making enamel, dentin, and complex tooth-like structures are presented in this paper. However, there are still significant barriers that obstruct such strategies to move into the regular clinic practice, and these should be overcome in order to have the regenerative dentistry as the important mean that can treat the consequences of tooth-related diseases.

  3. Sealing Occlusal Dentin Caries in Permanent Molars

    DEFF Research Database (Denmark)

    Qvist, Vibeke; Borum, Mette Kit; Møller, Kirsten Dynes

    2017-01-01

    The purpose of this study was to investigate the possibility of postponing restorative intervention of manifest occlusal caries in young, permanent dentition by non-invasive sealing. This RCT-designed study included 521 occlusal lesions in 521 patients aged 6 to 17 y. Based on clinical and radiog......The purpose of this study was to investigate the possibility of postponing restorative intervention of manifest occlusal caries in young, permanent dentition by non-invasive sealing. This RCT-designed study included 521 occlusal lesions in 521 patients aged 6 to 17 y. Based on clinical...... longevity of sealings and restorations until retreatments, and 3) compare effectiveness of sealings and restorations to halt caries progression in sealed lesions and beneath restorations. Furthermore, we aimed to identify factors influencing longevity and the effectiveness of sealings and restorations.......001). The median survival time for sealings not replaced by restorations was 7.3 y (CI, 6.4 y to NA). Survival of sealings was increased in patients with low caries risk and/or excellent oral hygiene, second molars compared with first molars, and lesions not extending the middle one-third of the dentin. Survival...

  4. [The durability of three self-etch adhesives bonded to dentin].

    Science.gov (United States)

    Tian, Fu-Cong; Wang, Xiao-Yan; Gao, Xue-Jun

    2013-04-01

    To investigate the durability of self-etch adhesives bonded to dentin in vitro. Forty-two extracted human molars were selected and occlusal dentin surfaces were exposed. The teeth were randomly distributed into three groups based on adhesives applied. The one-step self-etch adhesive B(Adper Prompt) and C(G-Bond) and two-step self-etch adhesive A (Clearfil SE bond) were used. After application of the adhesives to the dentin surfaces, composite crowns were built up, after 24 h water storage, the teeth were sectioned longitudinally into sticks (1.0 mm×1.0 mm bonding area) for microtensile testing or slabs (1 mm thick) for scanning electron microscopec (SEM) observation. Bonding strength (mTBS) and nano-leakage were evaluated immediately after cutting or after 6 months in water. The mTBS was analyzed using one-way ANOVA (SPSS 13.0). The nanoleakage was observed by SEM with a backscattered electron detector. Both adhesives and water storage time affected the mTBS. All adhesives showed decreased bond strength after six-month water aging [A dropped from (40.60 ± 5.76) MPa to (36.04 ± 3.15) MPa; B dropped from (19.06 ± 1.50) MPa to (11.19 ± 1.97) MPa; C dropped from (17.75 ± 1.10) MPa to (9.14 ± 1.15) MPa] (P adhesives tested were probably influenced by water aging, however, the two-step adhesive showed better durability than the one-step adhesives.

  5. Influence of dentin contamination by temporary cements on the bond strength of adhesive systems

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    Josimeri Hebling

    2009-01-01

    Full Text Available Objective: The aim of this study was to assess the bond strength of adhesive systems to dentin contaminated by temporary cements with or without eugenol. Method: Flat dentin surfaces were obtained from twenty-four human third molars. With exception of the control group (n=8, the surfaces were covered with Interim Restorative Material (Caulk Dentsplay, Milford, DE, USA or Cavit (3M ESPE, St. Paul, MN, USA and kept in an oven at 37oC for seven days. After removing the cements, the adhesive systems Adper Single Bond (3M ESPE, St. Paul, MN, USA or Clearfil SE Bond (Kuraray Co. Ltd., Osaka, Japan were applied in accordance with the manufacturers’ recommendations, and then the crowns were constructed in of resin composite. The teeth were sectioned into specimens with a cross-sectional bond area of 0.81mm2, which were sub mitted to microtensile testing in a mechanical test machine at an actuator speed of 0.5mm/min. The data were analyzed by t- and ANOVA tests, complemented by Tukey tests (α=0.05. Results: For Adper Single Bond (3M ESPE, St. Paul, MN, USA, bond strength did not differ statistically (p>0.05 for all the experimental conditions. For Clearfil SE Bond (Kuraray Co. Ltd., Osaka, Japan, only the Interim Restorative Material (Caulk Dentsplay, Milford, DE, USA Group showed significantly lower bond strength (30.1±13.8 MPa in comparison with the other groups; control (38.9±13.5 MPa and Cavit (3M ESPE, St. Paul, MN, USA (42.1±11.0 MPa, which showed no significant difference between them.Conclusion: It was concluded that the previous covering of dentin with temporary cement containing eugenol had a deleterious effect on the adhesive performance of the self-etching system only.

  6. Effect of dentin pretreatment with potassium oxalate: analysis of microtensile bond strengths and morphologic aspects.

    Science.gov (United States)

    De Moraes Porto, Isabel Cristina Celerino; De Andrade, Ana Karina Maciel; Alves, Luiz Carlos; Braz, Rodivan

    2012-02-01

    An effective and stable bond is the most desirable characteristic of contemporary adhesive systems. The aim of this study was to evaluate the effect of potassium oxalate on dentin/resin bond strength. Dentin on the occlusal surface of human premolars was exposed and etched with 35% phosphoric acid, to receive 3% monohydrated potassium oxalate and the following adhesive systems: Scotchbond Multipurpose (SMO; 3M/ESPE) and Prime & Bond NT (PBO; Dentsply), followed by the application of resin composite (Z250; 3M/ESPE). The control groups (SM and PB) did not receive potassium oxalate application. The prepared teeth were kept in distilled water at 37°C for 24 h and 12 months. They were then cut longitudinally into sticks with a bond area of ∼0.8 mm(2) for submission to the microtensile bond strength test. The data were analyzed by two-factor ANOVA, Tamhane's paired comparisons, and the Student t-test (α = 0.05). The hybrid layer formed was observed by scanning electron microscopy (SEM). SEM analysis of the surfaces treated with PB revealed shorter resin tags associated with the application of potassium oxalate, whereas SM showed tags similar to those without potassium oxalate. A significant difference was shown between the two storage times for each of the protocols. There was a significant difference among SMO, SM, and PBO (24 h), as well as among SM, SMO, and PBO, and between PB and PBO (12 months). The application of potassium oxalate before conventional adhesive systems may result in alteration of the bond strength between dentin and resin composite, depending on the material. Copyright © 2011 Wiley Periodicals, Inc.

  7. Effect of simulated pulpal pressure on all-in-one adhesive bond strengths to dentine.

    Science.gov (United States)

    Hosaka, Keiichi; Nakajima, Masatoshi; Yamauti, Monica; Aksornmuang, Juthatip; Ikeda, Masaomi; Foxton, Richard M; Pashley, David H; Tagami, Junji

    2007-03-01

    To evaluate the durability of all-in-one adhesive systems bonded to dentine with and without simulated hydrostatic pulpal pressure (PP). Flat dentine surfaces of extracted human molars were prepared. Two all-in-one adhesive systems, One-Up Bond F (OBF) (Tokuyama Corp., Tokyo, Japan), and Fluoro Bond Shake One (FBS) (Shofu Co., Kyoto, Japan) were applied to the dentine surfaces under either a PP of 0 or 15cm H(2)O. Then, resin composite build-ups were made. The specimens bonded under pressure were stored in 37 degrees C water for 24h, 1 and 3 months under 15cm H(2)O PP. Specimens not bonded under pressure were stored under zero PP. After storage, the specimens were sectioned into slabs that were trimmed to hourglass shapes and subjected to micro-tensile bond testing (muTBS). The data were analysed using two-way ANOVA and Holm-Sidak HSD multiple comparison tests (alpha=0.05). The muTBS of OBF fell significantly (phydrostatic pressure storage fell significantly over the 3 months period, the decrease was less than half as much as specimens stored under PP. In FBS bonded specimens, although there was no significant difference between the muTBS with and without hydrostatic pulpal pressure at 24h, by 1 and 3 months of storage under PP, significant reductions were seen compared with the control group without PP. The muTBS of OBF bonded specimens was lowered more by simulated PP than by storage time; specimens bonded with FBS were not sensitive to storage time in the absence of PP, but showed lower bond strengths at 1 and 3 months in the presence of PP.

  8. Ceramic Inlays: Effect of Mechanical Cycling and Ceramic Type on Restoration-dentin Bond Strength.

    Science.gov (United States)

    Trindade, F Z; Kleverlaan, C J; da Silva, L H; Feilzer, A J; Cesar, P F; Bottino, M A; Valandro, L F

    2016-01-01

    This study aimed to evaluate the bond strength between dentin and five different ceramic inlays in permanent maxillary premolars, with and without mechanical cycling. One hundred permanent maxillary premolars were prepared and divided into 10 groups (n=10) according to the ceramic system (IPS e.Max Press; IPS e.Max CAD; Vita PM9; Vita Mark II; and Vita VM7) and the mechanical cycling factor (with and without [100 N, 2 Hz, 1.2×10(6) cycles]). The inlays were adhesively cemented, and all of the specimens were cut into microbars (1×1 mm, nontrimming method), which were tested under microtensile loading. The failure mode was classified and contact angle, roughness, and microtopographic analyses were performed on each ceramic surface. The mechanical cycling had a significant effect (p=0.0087) on the bond strength between dentin and IPS e.max Press. The Vita Mark II group had the highest bond strength values under both conditions, with mechanical cycling (9.7±1.8 MPa) and without (8.2±1.9 MPa), while IPS e.Max CAD had the lowest values (2.6±1.6 and 2.2±1.4, respectively). The adhesive failure mode at the ceramic/cement interface was the most frequent. Vita Mark II showed the highest value of average roughness. IPS e.max Press and Vita Mark II ceramics presented the lowest contact angles. In conclusion, the composition and manufacturing process of ceramics seem to have an influence on the ceramic surface and resin cement bond strength. Mechanical cycling did not cause significant degradation on the dentin and ceramic bond strength under the configuration used.

  9. The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate

    Science.gov (United States)

    Pilo, Raphael; Harel, Noga; Nissan, Joseph; Levartovsky, Shifra

    2016-01-01

    The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP) crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC) or Self Adhesive Resin Cement (SARC)). Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa) were significantly higher than those for SARC (2.28 ± 0.58 MPa). The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns. PMID:27023532

  10. Secondary mineralization in carious lesions of human dentin. Electron-probe, electron microscope, and electron diffraction studies

    Energy Technology Data Exchange (ETDEWEB)

    Ogiwara, H [Tokyo Dental Coll. (Japan)

    1975-02-01

    Dentinal carious lesions having a remineralized surface layer were studied by means electron-probe microanalysis, electron microscopy, electron diffraction. As the results of electron-probe study, F, Mg, and Na were found to be distributed mainly in the remineralized surface layer and S in the decalcified region where decreases in Ca, P, and Mg concentration were usually observed. The decrease in Mg concentration always started earlier than that of Ca and P concentration. Electron microscope and electron diffraction studies revealed that apatic crystals in the remineralized surface layer were much larger than those in the intact dentin. Although they were less conspicuous, crystals in the decalcified region also were larger than those in the intact region. Dentinal tubules, occluded by many crystals, were frequently seen during the observations. Crystals in the tubules varied in morphology, showing granular, needle, rhomboid, and tabular shapes. By means of electron diffraction, the granular- or needle-shaped crystals were identified as apatite and the rhomboid-shaped crystals as whitlockite. Some of the tabular-shaped crystals appeared to be cotacalcium phosphate.

  11. Morphological alterations of radicular dentine pretreated with different irrigating solutions and irradiated with 980-nm diode laser.

    Science.gov (United States)

    Alfredo, Edson; Souza-Gabriel, Aline E; Silva, Silvio Rocha C; Sousa-Neto, Manoel D; Brugnera-Junior, Aldo; Silva-Sousa, Yara T C

    2009-01-01

    The topographical features of intraradicular dentine pretreated with sodium hypochlorite (NaOCl) or ethylenediamine tetraacetic acid (EDTA) followed by diode laser irradiation have not yet been determined. To evaluate the alterations of dentine irradiated with 980-nm diode laser at different parameters after the surface treatment with NaOCl and EDTA. Roots of 60 canines were biomechanically prepared and irrigated with NaOCl or EDTA. Groups were divided according to the laser parameters: 1.5 W/CW; 1.5 W/100 Hz; 3.0 W/CW; 3.0 W/100 Hz and no irradiation (control). The roots were splited longitudinally and analyzed by scanning electron microscopy (SEM) in a quali-quatitative way. The scores were submitted to two-way Kruskal-Wallis and Dunn's tests. The statistical analysis demonstrated that the specimens treated only with NaOCl or EDTA (control groups) were statistically different (P laser-irradiated specimens, regardless of the parameter setting. The specimens treated with NaOCl showed a laser-modified surface with smear layer, fissures, and no visible tubules. Those treated with EDTA and irradiated by laser presented absence of smear layer, tubules partially exposed and melting areas. The tested parameters of 980-nm diode laser promoted similar alterations on dentine morphology, dependent to the type of surface pretreatment. Copyright 2008 Wiley-Liss, Inc.

  12. The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate

    Directory of Open Access Journals (Sweden)

    Raphael Pilo

    2016-03-01

    Full Text Available The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC or Self Adhesive Resin Cement (SARC. Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa were significantly higher than those for SARC (2.28 ± 0.58 MPa. The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns.

  13. A micromorphological study of pedogenic processes in an evolutionary soil sequence formed in late quaternary rhyolitic tephra deposits, North Island, New Zealand.

    NARCIS (Netherlands)

    Bakker, L.; Lowe, D.J.; Jongmans, A.G.

    1996-01-01

    The influence of time as a soil forming factor was studied on an evolutionary sequence of five soils (1850 radiocarbo years BP-ca. 120,000 BP) developed in rhyolitic tephra deposits in New Zealand. New micromorphological observations were combined with existing macromorphological, chemical,

  14. Micromorphology of Paleosols of the Marília Formation and their Significance in the Paleoenvironmental Evolution of the Bauru Basin, Upper Cretaceous, Southeastern Brazil

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    Márcio Luiz da Silva

    Full Text Available ABSTRACT Deduction of associated paleoenvironments and paleoclimate, definition of the chronosequence of paleosols, and paleogeographic reconstruction have become possible through the application of micromorphology in paleopedology. Micromorphology has also been useful in recognition of weathering processes and definition of minerals formed in succession. In this respect, the objective of this study was to identify the development of pedogenic processes and discuss their significance in the paleoclimate evolution of the Marília Formation (Maastrichtian of Bauru Basin. Three sections of the Marília Formation (A1, A2, and A3 were described, comprising nine profiles. Micromorphologic al analysis was carried out according to the specialized literature. In the Marília Formation, the paleosols developed in sandstones have argillic (Btkm, Bt and carbonate (Bk horizons with different degrees of cementation, forming mainly calcretes. The evolution of pedogenic processes, in light of micromorphological analysis, evidenced three moments or stages for the genesis of paleosols with Bkm, Btk, and Bt horizons, respectively. In the Maastrichtian in the Bauru Basin, the paleosols with Bkm are older and more arid environments, and those with Bt were formed in wetter weather, but not enough to lead to the genesis of enaulic-related distributions, typical of current Oxisols.

  15. The fracture properties and toughening mechanisms of bone and dentin

    Science.gov (United States)

    Koester, Kurt John

    The mechanical properties of bone and dentin and in particular their fracture properties, are the subject of intense research. The relevance of these properties is increasing as our population ages and fracture incidence impacts the lives of a greater portion of the population. A robust framework is needed to understand the fracture properties of bone and dentin to guide researchers as they attempt to characterize the effects of aging, disease, and pharmaceutical treatments on the properties of these mineralized tissues. In the present work, this framework is provided and applied to human bone, human dentin, and animal bone. In situ electron microscopy was also used to identify the salient toughening mechanisms in bone and dentin. It was found that bone and dentin are extrinsically toughened materials and consequently their fracture properties are best characterized utilizing a crack-growth resistance approach. A description of the different mechanical measurements commonly employed when using small animal models (rats and mice) to evaluate the influence of drug therapies on bone fragility is provided. A study where these properties were measured for a large population of wild-type rats and mice was also conducted. Given my findings, it was determined that for the most complete understanding of small animal bone it was necessary to measure strength and toughness. Strength measurements probe the flaw distribution and toughness measurements to evaluate the resistance to facture in the presence of a single dominant worst-case flaw.

  16. Dentin and dental pulp regeneration by the patient's endogenous cells.

    Science.gov (United States)

    Kim, Sahng G; Zheng, Ying; Zhou, Jian; Chen, Mo; Embree, Mildred C; Song, Karen; Jiang, Nan; Mao, Jeremy J

    2013-03-01

    The goal of regenerative endodontics is to restore the functions of the dental pulp-dentin complex. Two approaches are being applied toward dental pulp-dentin regeneration: cell transplantation and cell homing. The majority of previous approaches are based on cell transplantation by delivering ex vivo cultivated cells toward dental pulp or dentin regeneration. Many hurdles limit the clinical translation of cell transplantation such as the difficulty of acquiring and isolating viable cells, uncertainty of what cells or what fractions of cells to use, excessive cost of cell manipulation and transportation, and the risk of immune rejection, pathogen transmission, and tumorigenesis in associated with ex vivo cell manipulation. In contrast, cell homing relies on induced chemotaxis of endogenous cells and therefore circumvents many of the difficulties that are associated with cell transplantation. An array of proteins, peptides, and chemical compounds that are yet to be identified may orchestrate endogenous cells to regenerate dental pulp-dentin complex. Both cell transplantation and cell homing are scientifically valid approaches; however, cell homing offers a number of advantages that are compatible with the development of clinical therapies for dental pulp-dentin regeneration.

  17. Effect of chlorhexidine application on the bond strength of resin core to axial dentin in endodontic cavity

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    Yun-Hee Kim

    2012-11-01

    Full Text Available Objectives This study evaluated the influence of chlorhexidine (CHX on the microtensile bonds strength (µTBS of resin core with two adhesive systems to dentin in endodontic cavities. Materials and Methods Flat dentinal surfaces in 40 molar endodontic cavities were treated with self-etch adhesive system, Contax (DMG and total-etch adhesive system, Adper Single Bond 2 (3M ESPE after the following surface treatments: (1 Priming only (Contax, (2 CHX for 15 sec + rinsing + priming (Contax, (3 Etching with priming (Adper Single Bond 2, (4 Etching + CHX for 15 sec + rinsing + priming (Adper Single Bond 2. Resin composite build-ups were made with LuxaCore (DMG using a bulk method and polymerized for 40 sec. For each condition, half of specimens were submitted to µTBS after 24 hr storage and half of them were submitted to thermocycling of 10,000 cycles between 5℃ and 55℃ before testing. The data were analyzed using ANOVA and independent t-test at a significance level of 95%. Results CHX pre-treatment did not affect the bond strength of specimens tested at the immediate testing period, regardless of dentin surface treatments. However, after 10,000 thermocycling, all groups showed reduced bond strength. The amount of reduction was greater in groups without CHX treatments than groups with CHX treatment. These characteristics were the same in both self-etch adhesive system and total-etch adhesive system. Conclusions 2% CHX application for 15 sec proved to alleviate the decrease of bond strength of dentin bonding systems. No significant difference was shown in µTBS between total-etching system and self-etching system.

  18. Effect of air-blowing duration on the bond strength of current one-step adhesives to dentin.

    Science.gov (United States)

    Fu, Jiale; Saikaew, Pipop; Kawano, Shimpei; Carvalho, Ricardo M; Hannig, Matthias; Sano, Hidehiko; Selimovic, Denis

    2017-08-01

    To evaluate the influence of different air-blowing durations on the micro-tensile bond strength (μTBS) of five current one-step adhesive systems to dentin. One hundred and five caries-free human molars and five current one-step adhesive systems were used: ABU (All Bond Universal, Bisco, Inc.), CUB (CLEARFIL™ Universal Bond, Kuraray), GPB (G-Premio BOND, GC), OBA (OptiBond All-in-one, Kerr) and SBU (Scotchbond Universal, 3M ESPE). The adhesives were applied to 600 SiC paper-flat dentin surfaces according to each manufacturer's instructions and were air-dried with standard, oil-free air pressure of 0.25MPa for either 0s, 5s, 15s or 30s before light-curing. Bond strength to dentin was determined by using μTBS test after 24h of water storage. The fracture pattern on the dentin surface was analyzed by SEM. The resin-dentin interface of untested specimens was visualized by panoramic SEM image. Data from μTBS were analyzed using two-way ANOVA (adhesive vs. air-blowing time), and Games-Howell (a=0.05). Two-way ANOVA revealed a significant effect of materials (p=0.000) and air-blowing time (p=0.000) on bond strength to dentin. The interaction between factors was also significantly different (p=0.000). Maximum bond strength for each system were recorded, OBA/15s (76.34±19.15MPa), SBU/15s (75.18±12.83MPa), CUB/15s (68.23±16.36MPa), GPB/30s (55.82±12.99MPa) and ABU/15s (44.75±8.95MPa). The maximum bond strength of OBA and SUB were significantly higher than that of GPB and ABU (padhesive systems is material-dependent (p=0.000), and was influenced by air-blowing duration (p=0.000). For the current one-step adhesive systems, higher bond strengths could be achieved with prolonged air-blowing duration between 15-30s. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  19. The Difference of Structural State and Deformation Behavior between Teenage and Mature Human Dentin

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    Peter Panfilov

    2016-01-01

    Full Text Available Objective. The cause of considerable elasticity and plasticity of human dentin is discussed in the relationship with its microstructure. Methods. Structural state of teenage and mature human dentin is examined by using XRD and TEM techniques, and their deformation behavior under compression is studied as well. Result. XRD study has shown that crystallographic type of calcium hydroxyapatite in human dentin (calcium hydrogen phosphate hydroxide Ca9HPO4(PO45OH; Space Group P63/m (176; a = 9,441 A; c = 6,881 A; c/a = 0,729; Crystallite (Scherrer 200 A is the same for these age groups. In both cases, dentin matrix is X-ray amorphous. According to TEM examination, there are amorphous and ultrafine grain phases in teenage and mature dentin. Mature dentin is stronger on about 20% than teenage dentin, while teenage dentin is more elastic on about 20% but is less plastic on about 15% than mature dentin. Conclusion. The amorphous phase is dominant in teenage dentin, whereas the ultrafine grain phase becomes dominant in mature dentin. Mechanical properties of human dentin under compression depend on its structural state, too.

  20. Different methods of dentin processing for application in bone tissue engineering: A systematic review.

    Science.gov (United States)

    Tabatabaei, Fahimeh Sadat; Tatari, Saeed; Samadi, Ramin; Moharamzadeh, Keyvan

    2016-10-01

    Dentin has become an interesting potential biomaterial for tissue engineering of oral hard tissues. It can be used as a scaffold or as a source of growth factors in bone tissue engineering. Different forms of dentin have been studied for their potential use as bone substitutes. Here, we systematically review different methods of dentin preparation and the efficacy of processed dentin in bone tissue engineering. An electronic search was carried out in PubMed and Scopus databases for articles published from 2000 to 2016. Studies on dentin preparation for application in bone tissue engineering were selected. The initial search yielded a total of 1045 articles, of which 37 were finally selected. Review of studies showed that demineralization was the most commonly used dentin preparation process for use in tissue engineering. Dentin extract, dentin particles (tooth ash), freeze-dried dentin, and denatured dentin are others method of dentin preparation. Based on our literature review, we can conclude that preparation procedure and the size and shape of dentin particles play an important role in its osteoinductive and osteoconductive properties. Standardization of these methods is important to draw a conclusion in this regard. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2616-2627, 2016. © 2016 Wiley Periodicals, Inc.

  1. In vitro marginal adaptation of high-viscosity resin composite restorations bonded to dentin cavities.

    Science.gov (United States)

    Rahiotis, Christos; Tzoutzas, John; Kakaboura, Afrodite

    2004-01-01

    The aim of this study was to evaluate the marginal adaptation of high-viscosity resin composite restoratives bonded to dentin in a cylindrical cavity model. The buccal enamel of 64 human premolars was removed and cylindrical cavities 3 mm in diameter and 1.3 mm in depth were prepared on each dentin surface. The cavities were divided into 8 groups of 8 cavities each and restored according to the manufacturers' instructions with the following adhesive/composite systems: Bond 1/Alert, Stae/Glacier, OptiBond Solo/Prodigy Condensable, One-Step/Pyramid, Solidbond/Solitaire, Prime&Bond NT/Surefil, One Coat Bond/Synergy, and Scotchbond 1/Z250. The composite surfaces were pressed against mylar strips, covered with cover slips, and photopolymerized in a single increment for 40 s. The restorations were polished with wet SiC papers of 320 to 1000 grit size to expose dentin margins. The marginal adaptation was evaluated immediately after photopolymerization and again after 1 week of storage in water at 37 +/- 1 degrees C. Evaluation was performed under a metallographic microscope at 200X magnification by recording the frequency of gap-free restorations (GF), the percentage length of the debonded margins relative to the cavity periphery (DM), the width of the maximum marginal gap (MG), and the marginal index (MI = MG x DM / 100). The results were statistically analyzed with one-way ANOVA and the Mann-Whitney U-test at alpha = 0.05. No incidence of gaps was found in 62.5% of One Coat Bond/Synergy and 37.5% of OptiBond Solo/Prodigy Condensable restorations. All the other restorative systems exhibited restorations with gaps. One Coat Bond/Synergy, Scotchbond 1/Z250, and OptiBond Solo/Prodigy Condensable were the groups with the lowest DM values, while Stae/Glacier showed the highest DM values. One Coat Bond/Synergy and OptiBond Solo/Prodigy Condensable revealed the lowest MI values and Stae/Glacier the highest. No statistically significant differences were recorded between

  2. Effects of different desensitizing treatments on root dentin permeability

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    Raydsa Raíssa Moura ROSA

    Full Text Available Abstract The objective of this study was to evaluate the effects of diode laser and a desensitizing dentifrice on dentin permeability. Fifty-two root dentin fragments were obtained (5 × 5mm and treated with 24% EDTA gel. The samples were divided into 4 groups (n = 13: G1, control (no treatment; G2, diode laser (λ = 908 nm, 1.5 W, continuous mode, 20s; G3, application of abrasive dentifrice for 1 minute (Elmex Sensitive Professional (International Gaba; and G4, application of abrasive dentifrice for 1 minute followed by irradiation with diode laser. Ten samples per group were immersed in 2% methylene blue solution for 4h. The specimens were washed, longitudinally sectioned, observed under optical microscopy, photographed and assessed based on the degree of dye leakage. The remaining samples were observed under scanning electron microscopy (SEM. The leakage data were subjected to ANOVA test, followed by Tukey’s t-test (α = 5%. Groups 2, 3 and 4 showed less dye penetration than the control group (p < 0.05, but were similar among each other. SEM images showed that dentinal tubules were open in G1, and fused and occluded in G2. Group 3 showed dentinal tubules that were occluded by the metal ions from the toothpaste. G4 presented similar characteristics to G3, and the presence of fused dentin. The diode laser and the dentifrice were effective in reducing dentinal permeability, and the combination of the two treatments did not show better results than either one used alone.

  3. Removal effects of the Nd:YAG laser and Carisolv on carious dentin.

    Science.gov (United States)

    Yamada, Y; Hossain, M; Kawanaka, T; Kinoshita, J; Matsumoto, K

    2000-10-01

    The purpose of this study was to investigate the removal effect of the Nd:YAG laser irradiation and Carisolv on carious dentin. Many previous studies have reported several simple and alternative techniques, such as lasers and chemicals, for caries removal. Carisolv was applied on the surface of 20 extracted human anterior and molar teeth for 1 min and then the Nd:YAG laser was irradiated with a continuous water spray for another 1 min. The energy densities were varied from 2 to 6W with a repetition rate of 20 pps. As caries removal progressed, the cavity was carefully assessed by DIAGNOdent. Each lesion was photographed before and after treatment, and the treated cavity was observed microscopically using a stereoscope and with scanning electron microscope (SEM). Thermal change at the time of laser irradiation was measured by thermovision. Our results revealed that application of Carisolv followed by Nd:YAG laser irradiation at 4-6W pulse energy effectively removed dentin caries. The total procedure was usually repeated once or twice for complete caries removal. From the SEM study, it was found that the cavity surface treated with the laser revealed various patterns of microirregularity, often accompanied by microfissure propagation. There was also no smear layer. It was revealed that Nd:YAG laser and Carisolv could provide an alternative technique for caries removal instead of the conventional mechanical drilling and cutting.

  4. Effectiveness of a baking soda toothpaste delivering calcium and phosphate in reducing dentinal hypersensitivity.

    Science.gov (United States)

    Ghassemi, A; Hooper, W; Winston, A E; Sowinski, J; Bowman, J; Sharma, N

    2009-01-01

    The purpose of this controlled clinical trial was to determine the effectiveness and safety of a single-phase dentifrice that delivers calcium, phosphate, and fluoride to the tooth surface (Arm & Hammer Enamel Care for Sensitive Teeth toothpaste, United Kingdom) in reducing dentinal hypersensitivity. Two-hundred and eight qualifying subjects were randomly assigned to either the Enamel Care dentifrice group or a control dentifrice group, and brushed twice daily with their assigned dentifrice for eight weeks. Pain/discomfort in response to a thermal stimulus was assessed at baseline, week 4, and week 8 using a Visual Analogue Scale (VAS; primary outcome variable) and the Schiff Thermal Sensitivity Scale (STSS; secondary outcome variable). After eight weeks, volunteers from the Enamel Care group were switched to the control dentifrice and participated in a second eight-week study to determine the degree of persistence of pain reduction. Both groups had statistically significant VAS score reductions from baseline at weeks 4 and 8, with mean VAS scores in the Enamel Care group decreasing by 45.6% at week 4 and 61.1% at week 8 (p < 0.0001). Enamel Care was statistically significantly more effective than the control at weeks 4 and 8, with respective mean VAS reductions of 63% (p < 0.0001) and 33% (p = 0.0004) greater than the control. Consistent with the VAS score results, the Enamel Care group had respective statistically significant STSS score reductions of 77% and 58% greater than the control group (p < 0.0001). The reductions in dentinal hypersensitivity seen in the Enamel Care group at week 8 persisted for an additional eight weeks, during which the subjects discontinued use of Enamel Care and brushed with the control dentifrice. Enamel Care for Sensitive Teeth toothpaste (United Kingdom) is an effective dentifrice for the management of dentinal hypersensitivity, and its efficacy persists for a least eight weeks following discontinued product use.

  5. Evaluation of the cavity margins after Er:YAG laser ablation of the enamel and dentin

    Science.gov (United States)

    Dostalova, Tatjana; Krejsa, Otakar; Jelinkova, Helena; Hamal, Karel

    1994-12-01

    This study investigates the checks of cavity margin after enamel and dentin ablation. The Er:YAG laser enamel and dentin ablation can be directly connected with the danger of cracks originating in the enamel near the cavity. This study evaluates the quality of the enamel edges after Er:YAG laser preparation. The enamel and dentin of buccal surfaces were ablated by the Er:YAG laser radiation. An Erbium:YAG laser system with the energy of 200 mJ was used to generate 200 microsecond(s) long pulses of mid-infrared 2.94 micrometers light in multimode configuration. The laser was operating in a free running mode, the repetition rate being 0.5 Hz with average laser power of 100 mW. Laser radiation was focused on the tooth tissue. Water cooling was used during the procedure in order to prevent tooth tissue destruction. The time of laser preparation was 5 minutes. A cavity of class V was prepared. The teeth were immersed into 0.5% basic fuchsin and then centrifuged at 6000 rev/min for 20 minutes. The microphotographs of the margins stained with 0.5% basic fuchsin were made and then the longitudinal section of the teeth were evaluated. The micrographs of the longitudinal section were checked and measured afterwards. The effect of the investigated laser irradiation on the origin of cracks was analyzed in the scanning electron microscope. Micrographs of each tooth before and after the laser ablation were compared. Micrographs of the intact teeth after extraction present the cracks of the enamel. They depend on the pressure exerted during extraction. The influence of the laser ablation proper is it bears no signs of new cracks. The conclusions of this study demonstrate the non-invasive nature of the Er:YAG laser ablation of the hard dental tissues.

  6. Efficacy of two commercially available dentifrices in reducing dentinal hypersensitivity

    Directory of Open Access Journals (Sweden)

    Prasad KVV

    2010-01-01

    Full Text Available Objective: A parallel design clinical study evaluated reduction in hypersensitivity after brushing for 12 weeks with Anchor toothpaste (containing potassium citrate, zinc citrate, triclosan and sodium monofluorophosphate (test and Colgate Total (sodium fluoride, silica, triclosan and copolymer (control dentifrices. Materials and Methods: Sixty adults with sensitivity to hot and cold stimulus in at least two tooth surfaces were stratified at the baseline examination by tactile, hot and cold stimuli scores in two balanced groups. Subjects were randomly allocated the test and control dentifrices and evaluated after 6 and 12 weeks of dentifrice use for hypersensitivity. Results: The two teeth that were selected in each patient were designated as two different sets. The 12 th -week scores as compared to baseline scores for tactile, heat and cold tests in the test group showed a reduction in tooth hypersensitivity by 36.67% (P < 0.01, 20.35% (P < 0.01 and 53.64 % (P < 0.01, respectively, in the first set of teeth and 43.75% (P < 0.01, 24.48% (P < 0.01 and 59.78% (P < 0.01, respectively, in the second set of teeth. The 12 th -week scores as compared to baseline scores for tactile, heat and cold tests in the control group showed a reduction in tooth hypersensitivity by 42.86% (P < 0.01, 13.02% (P < 0.01 and 45.14% (P < 0.01, respectively, in the first set of teeth and 40% (P < 0.01, 16.59% (P < 0.01 and 44.16% (P < 0.01, respectively, in the second set of teeth. Conclusions: Both the products reduced dentinal hypersensitivity in the study subjects at the end of the 12-week period. However, there was no statistically significant difference in reduction in hypersensitivity between the two products.

  7. Effect of immediate and delayed dentin sealing on the fracture strength, failure type and Weilbull characteristics of lithiumdisilicate laminate veneers

    NARCIS (Netherlands)

    Gresnigt, Marco M.M.; Cune, Marco S.; de Roos, Joanne G.; Özcan, Mutlu

    OBJECTIVES: Adhesion on dentin is less reliable than on enamel, which could affect the durability of laminate veneers (LV). Immediate dentin sealing (IDS) is suggested instead of delayed dentin sealing (DDS) to overcome hypersensitivity and prevent debonding from dentin. This study evaluated the

  8. Clinical and morphologic evaluation of Er:YAG laser action at the front of cervical dentinal hypersensitivity

    International Nuclear Information System (INIS)

    Rocha, Dalva Maria

    2001-01-01

    This work was achieved in vivo and in vitro to evaluate the efficiency of Er:YAG laser in the cervical dentinal hypersensitivity treatment (HSDC). The Clinical study was achieved in patients with HSDC. The treatment was realized in five sessions: the first for selection, the second for exams (clinic and X-Ray) and trying to remove the etiologic factors that could cause the HSDC. The third and fourth sessions were subjected to the radiation with that protocol: 60 mJ energy ,2 Hz frequency, 6 mm out of focus, under air cooling, 20 seconds each application which the same was repeated four times with one minute breaks, which scanning movements and without using anaesthetics. The fifth was evaluation. The patients were evaluated and registered in a subject scale of pain 0 to 3, in the beginning and end of each session of irradiation, and one month after the last session. The results showed that for the irradiated group occurs significant differences in the beginning of each session and between. For the control group did not occur significant differences in the beginning and after each session, but did show a difference between the sessions. As the control group as the irradiated group, had reduction of sensibility between the session. For the morphologic study nine teeth were selected, 7 molars and 2 pre-molars from operative dentistry discipline. Half of the surface was irradiated with Er:YAG laser, the same protocol used in vivo, and the other half was used as a control without receiving any laser irradiation. Subsequently, specimens were prepared for SEM examinations. The results showed that laser treated surfaces showed a reduction of dentine tubular diameter with partial or total closure of the dentine tubules. For the control group, it was observed bigger amounts smear layer and open dentine tubular. The results obtained indicated that the Er:YAG laser can contribute to the HSDC treatment. (author)

  9. Kekuatan Rekat Restorasi Komposit Resin pada Permukaan Dentin dengan Sistem Adhesif Self-Etch dalam Berbagai Temperatur

    Directory of Open Access Journals (Sweden)

    Iin Sundari

    2012-10-01

    Full Text Available Single-step self-etch adhesive systems are the system that combine self etching primer and bonding agent into one step application. This system was developed as the effort to simplified in application prosedures and give a good bond strength of resin composites to dentin surface. The purpose of this study was to examine the bond strength of resin composites with two singlestep self-etch adhesives system (Xeno III and Clearfil Tri-S Bond to bovine dentin at temperature of adhesive 3ºC, 22ºC and 30ºC. Adhesive was applied to dentin surface (bovine insisivus mandibular dentin follow by resin composites bonded according to the manufacturer’s instructions. Tensile bond strength of 60 specimens were tested UTM (universal testing machine after 24 hours storage in aquadest at 37 ºC. The results were analyzed using ANOVA test followed by Tukey’s test (p< 0,05. The bond strength of Xeno III was significantly diffrent from that of Clearfil tri-S Bond, 0,66±0,271, 2,70±1,528, 0,23±0,104 versus 2,07±0,272, 4,77±0,689, 4,39±1,205 MPa at temperature of materials 3ºC, 22ºC and 30ºC respectively. The bond strength of two single- step adhesives system (Xeno III and Clearfil Tri-S Bond were highest at temperature 22ºC than other temperatures of materials.DOI: 10.14693/jdi.v15i3.34

  10. In vivo evaluation of microleakage from composites with new dentine adhesives.

    Science.gov (United States)

    Koliniotou-Koumpia, E; Dionysopoulos, P; Koumpia, E

    2004-10-01

    The purpose of this study was to investigate microleakage in V class composite restorations with total etch versus self-etching adhesives. Experiments were conducted in vivo and were also evaluated interfacial micromorphology. Forty class V cavities were prepared on the buccal surfaces of teeth in three healthy dogs. The cavities were randomly assigned into five groups of eight teeth and restored with one of the following adhesive systems: Etch and Prime 3.0/Definite flow/Definite, Prompt L-pop/Filtek flow/P-60, Admira bond/Admira Flow /Admira, Bond 1/Flow it/Alert, Stae/Wave/Glacier. After 60 days the animals were killed and the teeth were extracted. The teeth were then immersed in a solution of 0.5% basic fuchsin dye for 24 h, sectioned and scored for microleakage. Features of the tooth/restoration interfaces were also examined using Scanning electron microscopy. Student-Newman-Keuls and one-way anova revealed significance differences among the groups for overall wall scores (P < 0.05). The total-etch adhesives revealed significantly less microleakage scores than the self-etching adhesive systems tested. Wilcoxon Signed Ranks Test revealed significant differences between the occlusal and gingival microleakage scores for each adhesive restorative system, with the exception of Admira (P < 0.05).

  11. Transmission electron microscopical study of teenage crown dentin on the nanometer scale

    Energy Technology Data Exchange (ETDEWEB)

    Panfilov, Peter, E-mail: peter.panfilov@urfu.ru [Ural Federal University, Ekaterinburg (Russian Federation); Kabanova, Anna [Ural Federal University, Ekaterinburg (Russian Federation); Guo, Jinming; Zhang, Zaoli [Erich Schmid Institute for Materials Science, Austrian Academy of Sciences, Leoben (Austria)

    2017-02-01

    Statement of significance: This is the first transmission electron microscopic study of teenage crown dentin on the nanometer scale. Samples for TEM were prepared by mechanical thinning and chemical polishing that allowed obtaining the electron transparent foils. It was firstly shown that human dentin possesses the layered morphology: the layers are oriented normally to the main axis of a tooth and have the thickness of ~ 50 nm. HA inorganic phase of teenage crown dentin is in the amorphous state. The cellular structure, which was formed from collagen fibers (diameter is ~ 5 nm), are observed near DEJ region in teenage dentin, whereas bioorganic phase of teenage crown dentin near the pulp camera does not contain the collagen fibers. Cracks in dentin thin foils have sharp tips, but big angles of opening (~ 30{sup °}) with plastic zone ahead crack tip. It means that young crown human dentin exhibits ductile or viscous-elastic fracture behavior on the nanometer scale. - Highlights: • Dentin has layered morphology. • Mineral component of dentin is in amorphous state. • Collagen fibers form cellular structure in dentin. • Cracks in dentin behave by elastic-plastic manner.

  12. Transmission electron microscopical study of teenage crown dentin on the nanometer scale

    International Nuclear Information System (INIS)

    Panfilov, Peter; Kabanova, Anna; Guo, Jinming; Zhang, Zaoli

    2017-01-01

    Statement of significance: This is the first transmission electron microscopic study of teenage crown dentin on the nanometer scale. Samples for TEM were prepared by mechanical thinning and chemical polishing that allowed obtaining the electron transparent foils. It was firstly shown that human dentin possesses the layered morphology: the layers are oriented normally to the main axis of a tooth and have the thickness of ~ 50 nm. HA inorganic phase of teenage crown dentin is in the amorphous state. The cellular structure, which was formed from collagen fibers (diameter is ~ 5 nm), are observed near DEJ region in teenage dentin, whereas bioorganic phase of teenage crown dentin near the pulp camera does not contain the collagen fibers. Cracks in dentin thin foils have sharp tips, but big angles of opening (~ 30 ° ) with plastic zone ahead crack tip. It means that young crown human dentin exhibits ductile or viscous-elastic fracture behavior on the nanometer scale. - Highlights: • Dentin has layered morphology. • Mineral component of dentin is in amorphous state. • Collagen fibers form cellular structure in dentin. • Cracks in dentin behave by elastic-plastic manner.

  13. Deformation behavior of human dentin in liquid nitrogen: a diametral compression test.

    Science.gov (United States)

    Zaytsev, Dmitry; Panfilov, Peter

    2014-09-01

    Contribution of the collagen fibers into the plasticity of human dentin is considered. Mechanical testing of dentin at low temperature allows excluding the plastic response of its organic matrix. Therefore, deformation and fracture behavior of the dentin samples under diametral compression at room temperature and liquid nitrogen temperature are compared. At 77K dentin behaves like almost brittle material: it is deformed exclusively in the elastic regime and it fails due to growth of the sole crack. On the contrary, dentin demonstrates the ductile response at 300K. There are both elastic and plastic contributions in the deformation of dentin samples. Multiple cracking and crack tip blunting precede the failure of samples. Organic phase plays an important role in fracture of dentin: plasticity of the collagen fibers could inhibit the crack growth. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Structure and microstructure of coronary dentin in non-erupted human deciduous incisor teeth

    Directory of Open Access Journals (Sweden)

    Costa Luciane R.R S.

    2002-01-01

    Full Text Available The dentin structure of non-erupted human deciduous mandibular and maxillary central and lateral incisor teeth was studied employing light and scanning electron microscopy. For light microscopy, nitric-acid-demineralized and ground sections were used. The sections were stained by hematoxylin-eosin, picrosirius and azo-carmim methods, and ground specimens were prepared using a carborundum disk mounted in a handpiece. For SEM study, teeth were frozen in liquid nitrogen and fractured at longitudinal and transversal directions. Structurally, demineralization and ground methods revealed tubules with primary and secondary curvatures, canaliculi, giant tubules, interglobular dentin, predentin, and intertubular dentin. Scanning electron microscopy showed three-dimensional aspects of dentinal tubules, canaliculi, peritubular dentin, intertubular dentin, and predentin. This study contributes to knowledge about dentin morphology showing characteristics of teeth not yet submitted to mastication stress.

  15. Comparative evaluation of shear bond strength of two self-etching adhesives (sixth and seventh generation on dentin of primary and permanent teeth: An in vitro study

    Directory of Open Access Journals (Sweden)

    Yaseen S

    2009-03-01

    Full Text Available Aim: The present study was undertaken to compare and evaluate shear bond strength of two self-etching adhesives (sixth and seventh generation on dentin of primary and permanent teeth. Materials and Methods: Flat dentin surface of 64 human anterior teeth (32 primary and 32 permanent divided into four groups of 16 each. Groups A and C were treated with Contax (sixth generation, while groups B and D were treated with Clearfil S3 (seventh generation. A teflon mold was used to build the composite (Filtek Z-350 cylinders on the dentinal surface of all the specimens. Shear bond strength was tested for all the specimens with an Instron Universal Testing Machine. Data were statistically analyzed using one-way ANOVA for multiple group comparison, followed by student′s unpaired ′t′ test for group-wise comparison. Results: There was no statistically significant difference in shear bond strength among the study groups except that primary teeth bonded with Contax exhibited significantly lesser shear bond strength than permanent teeth bonded with Clearfil S3. Conclusion: This study revealed that Clearfil S3 could be of greater advantage in pediatric dentistry than Contax because of its fewer steps and better shear bond strength in dentin of both primary and permanent teeth.

  16. Nd:YAG laser associated with metal salts solutions in the treatment of dentinal hypersensitivity

    International Nuclear Information System (INIS)

    Glauche, Carlos Eugenio Correia

    2001-01-01

    The objective of this study was to observe the ultrastructural changes caused by the radiation of Nd:YAG laser on the tooth tissue and determine qualitatively the presence of Sn ++ , Sr ++ and F - , inside the dentin, being it irradiated or not. Ten molar teeth recently extracted were cut into 2 mm discs. The samples were soaked in a EDTA solution at 17% for 2 minutes and divided into five groups. Group I: the samples were irradiated with Nd:YAG laser (1,5 W, 100 mJ, 15 Hz, 150 μs and 125 J/cm 2 ) and after that, a treatment with an SnF 2 aqueous solution at 10% for 30 minutes. Group II: the samples got laser irradiation with the same parameters and then a treatment with an SrCl 2 solution at 10% as a toothpaste (Sensodyne TM ) for 30 minutes. Group III: the samples just got a treatment with a SnF 2 aqueous solution at 10% for 30 minutes. Group IV: the samples just got a treatment with a SrCl 2 toothpaste (Sensodyne TM ) for 30 minutes. Group V: samples that just got laser irradiation in the parameters above mentioned. Then, all samples were prepared for scanning electronic microscopy (SEM) and the samples of groups I, II, III and IV for energy dispersive X-ray microanalysis (EDX). The ultrastructure aspect of the dentin showed the surface totally altered by the irradiation. Pits and whitish globules were found amidst an heterogenous and rough structure, due to the melting and resolidification of the dental structure. Craters were also observed. Carbonization areas were absent. Ions Sn ++ were found at a depth of 250 μm in the samples of group I (Nd:YAG + SnF 2 ), whereas in the samples of group III, Sn ++ were not found deeper than 100 μm. Sr ++ could be detected at least at 500 μm in the inner dentin in the samples of group II (Nd:YAG + SrCl 2 ). However, Sn ++ were not found at 50 μm in group IV samples. Ions F - were just found in the irradiated samples of group I. According to the study results we observed that through ultrastructural changes, caused by

  17. Cyclic testing of porcelain laminiate veneers on superficial enamel and dentin: Pressed vs. conventional layered porcelain

    Science.gov (United States)

    Tawde, Shweta

    specimens were fabricated with making a wax-up of the required dimensions and pressing them in the Programmat 5000 system after sprueing and investing them. After all the 40 veneers were checked for internal fit and margins/edges, they were cemented with Variolink Veneer luting cement. Prior to that, the veneers and teeth were prepared for cementation with IPS Ceramic Etching gel and Monobond S and teeth were prepared with Total Etch and ExciTE bond. A thin coat of Rubber separating medium was applied on the root surface of the teeth to simulate the periodontal ligament. Teeth were mounted in Resin rock at 45°. Cyclic loading on an Instron 5848 testing machine was performed. Compressive loading was applied in a cyclical manner using a ramp waveform at a rate of 50N/s. Failure was defined as a crack in the veneer, a crack in the tooth of the veneer, delamination or fracture lines on the veneer/tooth surface. For the first 1000 cycles, the maximum amplitude of the loading was 50N.If the construct survived, another 1000 cycles of loading were applied, using maximum amplitude of 100N. Energy to Failure evaluation was conducted to evaluate the amount of energy the construct absorbed before it failed. All specimens were classified as to whether they survived 2000 cycles of loading, failed during the 100N cyclic loading, or failed during the 50 N cyclic loading. Results: A total of 33 specimens were included in the study. 7 specimens showed catastrophic failure in the initial phases of setting-up the testing parameters on the Instron machine. Mean survivability was higher for the stackable material than the pressed material, and for the veneers attached to enamel than to dentin. When only the material was considered, there was a statistically significant difference between the two groups (p=0.032) in terms of overall survivability with more of the stackable veneers surviving the testing. When the element of veneer thickness is added to the data analysis, failure mode analysis

  18. Penetration of varnishes into demineralized root dentine in vitro

    NARCIS (Netherlands)

    Arends, J; Duschner, H; Ruben, JL

    1997-01-01

    In this paper the penetration of three different varnishes employed in caries prevention (Duraphat(R), Fluor Protector(R) and Cervitec(R)) into demineralized dentine is quantified using confocal laser scanning microscopy. The results show that the varnish penetration into lesions about 85 mu m in

  19. Bonding strategies for MIH-affected enamel and dentin.

    Science.gov (United States)

    Krämer, Norbert; Bui Khac, Ngoc-Han Nana; Lücker, Susanne; Stachniss, Vitus; Frankenberger, Roland

    2018-02-01

    Aim of the present study was to evaluate resin composite adhesion to dental hard tissues affected by molar incisor hypomineralisation (MIH). 94 freshly extracted human molars and incisors (53 suffering MIH) were used. 68 teeth (35 with MIH) were used for μ-TBS tests in enamel and dentin, 26 (18 with MIH) for qualitative evaluation. Specimens were bonded with Clearfil SE Bond, Scotchbond Universal, and OptiBond FL. For MIH affected enamel, additional OptiBond FL groups with NaOCl and NaOCl+Icon were investigated. Beside fractographic analysis, also qualitative evaluations were performed using SEM at different magnifications as well as histological sectioning. Highest μ-TBS values were recorded with dentin specimens (ANOVA, mod. LSD, p0.05). Pre-test failures did not occur in dentin specimens. Sound enamel specimens exhibited significantly higher μ-TBS values than MIH enamel (p0.05), however, it caused less pre-test failures (pMIH enamel is the limiting factor in adhesion to MIH teeth. MIH-affected dentin may be bonded conventionally. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  20. Dentin dysplasia type I : Five cases within one family

    NARCIS (Netherlands)

    Kalk, WWI; Batenburg, RHK; Vissink, A

    Five cases of dentin dysplasia type I within one family are described. Clinically and radiologically, such patients are characterized by a delayed eruption pattern, opacity of the incisional margins, hypermobility of the teeth, short and defective roots, and obliterated pulp chambers. A conservative

  1. Amalgam stained dentin: a proper substrate for bonding resin composite?

    NARCIS (Netherlands)

    Scholtanus, J.D.

    2016-01-01

    Nowadays the use of dental amalgam is mostly abandoned and substituted by tooth colored resin composites that can be bonded to teeth tissues by adhesive techniques. The aim of this thesis was to find out whether dark stained dentin, as often observed after removal of amalgam restorations and

  2. Bio-reconstruction of root canal using dentin post

    Directory of Open Access Journals (Sweden)

    Navin Mishra

    2013-01-01

    Full Text Available This case report describes the successful management of complicated crown fracture of left maxillary central incisor (#21 of 23-year-old male using dentin (biological post made from human tooth. Endodontic treatment was initiated and sectional obturation was done using ProTaper gutta-percha and AH Plus sealer. The coronal space was modified to receive a human dentin post. A two-step procedure comprising direct and indirect technique of post fabrication was done to achieve the accuracy of biological post. A maxillary cuspid from an institutional tooth bank was taken, sectioned mesiodistally using a diamond disc simulating the length and thickness of mock post. Dentin post was first verified on the plaster model and then cemented in tooth #21. Core build up was done with composite and porcelain fused to metal (PFM crown was luted. On the follow-up visits, patient was asymptomatic and radiographic evaluation revealed normal periradicular architecture. Biological posts may be good alternatives to conventional post systems as they preserve internal dentin walls, provide excellent adhesion, and resilience similar to natural tooth structure.

  3. Cyclophilin B Deficiency Causes Abnormal Dentin Collagen Matrix.

    Science.gov (United States)

    Terajima, Masahiko; Taga, Yuki; Cabral, Wayne A; Nagasawa, Masako; Sumida, Noriko; Hattori, Shunji; Marini, Joan C; Yamauchi, Mitsuo

    2017-08-04

    Cyclophilin B (CypB) is an endoplasmic reticulum-resident protein that regulates collagen folding, and also contributes to prolyl 3-hydroxylation (P3H) and lysine (Lys) hydroxylation of collagen. In this study, we characterized dentin type I collagen in CypB null (KO) mice, a model of recessive osteogenesis imperfecta type IX, and compared to those of wild-type (WT) and heterozygous (Het) mice. Mass spectrometric analysis demonstrated that the extent of P3H in KO collagen was significantly diminished compared to WT/Het. Lys hydroxylation in KO was significantly diminished at the helical cross-linking sites, α1/α2(I) Lys-87 and α1(I) Lys-930, leading to a significant increase in the under-hydroxylated cross-links and a decrease in fully hydroxylated cross-links. The extent of glycosylation of hydroxylysine residues was, except α1(I) Lys-87, generally higher in KO than WT/Het. Some of these molecular phenotypes were distinct from other KO tissues reported previously, indicating the dentin-specific control mechanism through CypB. Histological analysis revealed that the width of predentin was greater and irregular, and collagen fibrils were sparse and significantly smaller in KO than WT/Het. These results indicate a critical role of CypB in dentin matrix formation, suggesting a possible association between recessive osteogenesis imperfecta and dentin defects that have not been clinically detected.

  4. Effect of dentin desensitizing procedures on methyl methacrylate ...

    African Journals Online (AJOL)

    Background: Acrylic and bisacryl resins are widely used both during the temporization phase as well as for provisional restorations and the effect of external agents on dentin sensitivity can be reduced by the ... Materials and Methods: Forty extracted restoration and caries free human premolar teeth were used in this study.

  5. Acid Etching as Surface Treatment Method for Luting of Glass-Ceramic Restorations, part 1: Acids, Application Protocol and Etching Effectiveness

    Directory of Open Access Journals (Sweden)

    Emilija Barjaktarova-Valjakova

    2018-03-01

    CONCLUSION: Acid etching of the bonding surface of glass - ceramic restorations is considered as the most effective treatment method that provides a reliable bond with composite cement. Selective removing of the glassy matrix of silicate ceramics results in a micromorphological three-dimensional porous surface that allows micromechanical interlocking of the luting composite.

  6. An investigation of dentinal fluid flow in dental pulp during food mastication: simulation of fluid-structure interaction.

    Science.gov (United States)

    Su, Kuo-Chih; Chuang, Shu-Fen; Ng, Eddie Yin-Kwee; Chang, Chih-Han

    2014-06-01

    This study uses fluid-structure interaction (FSI) simulation to investigate the relationship between the dentinal fluid flow in the dental pulp of a tooth and the elastic modulus of masticated food particles and to investigate the effects of chewing rate on fluid flow in the dental pulp. Three-dimensional simulation models of a premolar tooth (enamel, dentine, pulp, periodontal ligament, cortical bone, and cancellous bone) and food particle were created. Food particles with elastic modulus of 2,000 and 10,000 MPa were used, respectively. The external displacement loading (5 μm) was gradually directed to the food particle surface for 1 and 0.1 s, respectively, to simulate the chewing of food particles. The displacement and stress on tooth structure and fluid flow in the dental pulp were selected as evaluation indices. The results show that masticating food with a high elastic modulus results in high stress and deformation in the tooth structure, causing faster dentinal fluid flow in the pulp in comparison with that obtained with soft food. In addition, fast chewing of hard food particles can induce faster fluid flow in the pulp, which may result in dental pain. FSI analysis is shown to be a useful tool for investigating dental biomechanics during food mastication. FSI simulation can be used to predict intrapulpal fluid flow in dental pulp; this information may provide the clinician with important concept in dental biomechanics during food mastication.

  7. Comparison of the remaining dentin thickness in the root after hand and four rotary instrumentation techniques: an in vitro study.

    Science.gov (United States)

    Rao, M S Rama; Shameem, Abdul; Nair, Rashmi; Ghanta, Sureshbabu; Thankachan, Rekha P; Issac, Johnson K

    2013-07-01

    The aim of the present study was to compare the remaining dental thickness (RDT) in the mesiobuccal root of mandibular first molars at 3 and 7 mm from the anatomic apex after instrumentation with ProTaper, light speed LSX, K3 and M2 and to compare with that of K-files. In this study, 60 extracted, untreated human mandibular first molars with fully formed apices, with curvature less than 35° and no root resorption were used. Prepared specimens were cut horizontally at 3 and 7 mm short of anatomic apex. The least dentin thickness from canal to external root surface was observed under 3× magnification and recorded using Clemax measuring tool and the sections were reassembled. Group I-instrumentation with ProTaper, group II-instrumentation with K3, group III-instrumentation with Light Speed LSX, group IV-instrumentation with M2 and group V- instrumentation with K-files and RDT was measured. Results showed that group V removed lesser amount of dentin compared to all other groups while all the three instrumentation techniques removed almost equal amount of dentin apically. Cleaning and shaping of the root canal space involves the elimination of pathogenic contents as well as attaining a uniform specific shape. However, the RDT following the use of various intraradicular procedures is an important factor to be considered as an iatrogenic cause that may result in root fracture. To avoid this, newer rotary instruments are being introduced.

  8. FT-Raman spectroscopy, µ-EDXRF spectrometry, and microhardness analysis of the dentin of primary and permanent teeth.

    Science.gov (United States)

    Torres, Carolina Paes; Miranda Gomes-Silva, Jaciara; Menezes-Oliveira, Maria Angélica Hueb; Silva Soares, Luís Eduardo; Palma-Dibb, Regina Guenka; Borsatto, Maria Cristina

    2018-05-01

    The chemical compositions (organic and inorganic contents) and mechanical behaviors of the dentin of permanent and deciduous teeth were analyzed and compared using X-ray fluorescence spectrometry (µ-EDXRF) Fourier transform Raman spectroscopy (FT-Raman) and a microhardness test (HD). Healthy fresh human primary and permanent molars (n = 10) were selected, The buccal surfaces facing upwards were stabilized in an acrylic plate, flattened, polished, and submitted to the µ-EDXRF, FT-Raman, and HD analysis. The results of the analysis were subjected to ANOVAs and Mann-Whitney U/Student's t multiple comparisons tests. The data showed similar values for the dentin of the primary and permanent teeth in P content, organic content (amide I peak), inorganic content ( PO43- - 430 and 590), and microhardness, Nevertheless, Ca content and Ca/P weight ratio were higher, and the CO32- peak was lower in the dentin of the permanent teeth compared to primary teeth. It be concluded that despite permanent teeth showed more Ca element, both substrates showed similar behavior of chemical and physical properties. © 2018 Wiley Periodicals, Inc.

  9. A comparison between new dentinal adhesives (fifth generation and traditional varnish in microleakage reduction of amalgam restorations in primary teeth

    Directory of Open Access Journals (Sweden)

    Mortazavi M. Associate Professor

    2003-06-01

    Full Text Available Statement of Problem: Microleakage presents the major cause for restorations failure in the oral cavity resulting in postoperative sensitivity, pulp irritation and secondary caries formation."nAim: The aim of this study was to compare two dentinal adhesive systems of fifth generation and copalite varnish in reducing microleakage of amalgam restorations in primary teeth."nMaterials and Methods: In this in-vitro study, 100 class V amalgam restorations were prepared on the buccal or lingual surfaces of primary molar and canine teeth. Samples were randomly divided into four groups (25 samples each. No liner was used for the first group and the second group restorations were lined with copalite varnish. Two dentin adhesives, called Syntac C and Single Bond, were used for the third and fourth groups, respectively. At the next stage, the samples were immersed in 5% fuschin solution for 24 hours, then sectioned buccolingually, and examined under a stereomicroscope for microleakage evaluation."nResults: There was a significant difference between four groups statistically (PO.000I, Comparing"nfour groups, the first and fourth ones, demonstrated the most and the least microleakage, respectively."nConclusion: The present study showed that new dentinal adhesive systems caused microleakage"nreduction in amalgam restorations of primary teeth.

  10. Quantitative analysis of aqueous phase composition of model dentin adhesives experiencing phase separation

    Science.gov (United States)

    Ye, Qiang; Park, Jonggu; Parthasarathy, Ranganathan; Pamatmat, Francis; Misra, Anil; Laurence, Jennifer S.; Marangos, Orestes; Spencer, Paulette

    2013-01-01

    There have been reports of the sensitivity of our current dentin adhesives to excess moisture, for example, water-blisters in adhesives placed on over-wet surfaces, and phase separation with concomitant limited infiltration of the critical dimethacrylate component into the demineralized dentin matrix. To determine quantitatively the hydrophobic/hydrophilic components in the aqueous phase when exposed to over-wet environments, model adhesives were mixed with 16, 33, and 50 wt % water to yield well-separated phases. Based upon high-performance liquid chromatography coupled with photodiode array detection, it was found that the amounts of hydrophobic BisGMA and hydrophobic initiators are less than 0.1 wt % in the aqueous phase. The amount of these compounds decreased with an increase in the initial water content. The major components of the aqueous phase were hydroxyethyl methacrylate (HEMA) and water, and the HEMA content ranged from 18.3 to 14.7 wt %. Different BisGMA homologues and the relative content of these homologues in the aqueous phase have been identified; however, the amount of crosslinkable BisGMA was minimal and, thus, could not help in the formation of a crosslinked polymer network in the aqueous phase. Without the protection afforded by a strong crosslinked network, the poorly photoreactive compounds of this aqueous phase could be leached easily. These results suggest that adhesive formulations should be designed to include hydrophilic multimethacrylate monomers and water compatible initiators. PMID:22331596

  11. Effect of tetracycline on the bond performance of etch-and-rinse adhesives to dentin

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    Rodrigo Stanislawczuk

    2011-10-01

    Full Text Available This study evaluated the effect of modified tetracycline on the resin-dentin bond strength (µTBS, silver nitrate uptake (SNU and solution homogeneity (SH of two adhesives. Dentin surfaces were treated with phosphoric acid, rinsed off and either rewetted with water (control group - CO, 2% minocycline (MI, 2% doxycyline (DO or 2% chlorhexidine (CH. Adhesive systems (Adper Single Bond 2 and Prime Bond NT and composite were applied and light-polymerized. Specimens were sectioned to obtain bonded sticks (0.8 mm² to test under tension at 0.5 mm/min. For SNU, specimens were immersed in silver nitrate and analyzed by EDX-SEM. SH was qualitatively analyzed after mixing the adhesives with different solvent-based solutions containing MI, DO and CH. Lower µTBS values were observed in the DO group compared with MI and CH (p = 0.01. Lower SNU was observed for MI and CH. The lowest µTBS for both adhesives was observed for the DO group (p = 0.01. Signs of phase separation were observed for DO with both adhesives. MI or CH used as rewetting solutions after acid etching did not affect the µTBS and hybrid layer quality.

  12. Effect of 10% sodium bicarbonate on bond strength of enamel and dentin after bleaching with 38% hydrogen peroxide

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    Fernanda Medeiros Darzé

    Full Text Available AbstractIntroductionBy-products of hydrogen peroxide degradation released during dental bleaching influence the polymerization of adhesive systems and composite resins, causing a reduction in shear bond strength to the tooth.Objectivethe aim of this article was to evaluate the effect of 10% sodium bicarbonate (SB, applied for different lengths of time, on the shear bond strength to enamel and dentin after bleaching.Material and methodEnamel and dentin blocks were divided into groups (n=10: (1 control: no bleaching; (2 immediate: bleaching immediately followed by restoration; (3 14-day: bleaching, restoration 14 days later; (4 SB for 10 minutes: bleaching, SB gel for 10 minutes, immediately followed by restoration; (5 SB for 20 minutes: bleaching, SB gel for 20 minutes, immediately followed by restoration. A 38% hydrogen peroxide gel (Opalescence Boost/Ultradent was used. After application of the adhesive system, composite resin cylinders were mounted on the surface of the substrates in order to test shear bond strength. Result: ANOVA and Tukey tests showed significantly higher mean enamel bond strength values for the 14-day follow-up group and without significant differences for control group. Mean bond strength values obtained for the other groups were intermediate. When testing dentin, the Tukey test revealed a significantly higher mean bond strength value for the 14-day follow-up group when compared with application of SB for 20 minutes.ConclusionSB gel applied was unable to reverse the low bond strength to enamel and dentin after bleaching treatment.

  13. Evaluation of the tensile bond strength of an adhesive system self-etching in dentin irradiated with Er:YAG laser; Avaliacao da resistencia a tracao de um sistema adesivo self-etching em dentina irradiada com Er:YAG laser

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Andrea Malluf Dabul de

    2000-07-01

    Since Buonocore (1955), several researchers have been seeking for the best adhesive system and treatment for the enamel and dentin surfaces. The use of the acid has been presented as one of the best techniques of dentin conditioning , because this promotes the removal of the 'smear layer and exhibition of dentinal structure, for a best penetration and micro- retention of the adhesive system. However, some conditioning methods have been appearing in the literature, for the substitution or interaction with the acid substances, as the laser. The objective of this work is to evaluate the tensile bond strength of the adhesive system self-etching' associated to a composed resin, in dentin surfaces conditioned with the Er:YAG laser. For this study, freshly extracted human teeth were used and in each one the dentinal surfaces , which were treated with three sandpapers of different granulations (120,400,600), to obtain a standard of the smear layer, before the irradiation of the laser and of the restoring procedure. After these procedures the specimens were storage in distilled water at 37 deg C for 24 hours. Soon after, they were submitted to the tensile strength test .After analyzing the results, we can concluded that the use of the Er:YAG laser can substitute the drill without the need of conditioning, when using the adhesive system 'self-etching' in the dentinal surfaces because there was a decline in the strength of adhesion in the groups conditioned with the laser. (author)

  14. In vivo model for microbial invasion of tooth root dentinal tubules

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    Jane L. BRITTAN

    2016-04-01

    Full Text Available ABSTRACT Objective Bacterial penetration of dentinal tubules via exposed dentine can lead to root caries and promote infections of the pulp and root canal system. The aim of this work was to develop a new experimental model for studying bacterial invasion of dentinal tubules within the human oral cavity. Material and Methods Sections of human root dentine were mounted into lower oral appliances that were worn by four human subjects for 15 d. Roots were then fixed, sectioned, stained and examined microscopically for evidence of bacterial invasion. Levels of invasion were expressed as Tubule Invasion Factor (TIF. DNA was extracted from root samples, subjected to polymerase chain reaction amplification of 16S rRNA genes, and invading bacteria were identified by comparison of sequences with GenBank database. Results All root dentine samples with patent tubules showed evidence of bacterial cell invasion (TIF value range from 5.7 to 9.0 to depths of 200 mm or more. A spectrum of Gram-positive and Gram-negative cell morphotypes were visualized, and molecular typing identified species of Granulicatella, Streptococcus, Klebsiella, Enterobacter, Acinetobacter, and Pseudomonas as dentinal tubule residents. Conclusion A novel in vivo model is described, which provides for human root dentine to be efficiently infected by oral microorganisms. A range of bacteria were able to initially invade dentinal tubules within exposed dentine. The model will be useful for testing the effectiveness of antiseptics, irrigants, and potential tubule occluding agents in preventing bacterial invasion of dentine.

  15. The effect of MTA application on the affected dentine remineralization after partial caries excavation (in vivo)

    Science.gov (United States)

    Pratiwi, A. R.; Meidyawati, R.; Djauharie, N.

    2017-08-01

    On deep carious lesions, only thin dentine remains, causing a high risk of pulp exposure during the removal of all infected dentine. A minimally invasive technique is required, such as a partial caries excavation method in the infected dentine tissue and the use of bioactive material that can promote (Mineral Trioxide Aggregate) MTA remineralization. To compare the remineralization of deep carious lesion-affected dentine with the removal of some and all the infected dentine after the application of MTA. Subjects were divided into two groups: group I had only some parts of the infected dentine removed before MTA application, while group II had all the infected dentine removed before MTA application. Each group was measured on the pixel grey value before the treatment and again four weeks after the MTA application, and then the results were compared. Furthermore, the enhancement of both groups’ grey values were compared. Remineralization occurred in both groups after the MTA application. There was no significant difference in the remineralization level of the affected dentine in both groups I and II four weeks after the MTA application. Remineralization occurred in the affected dentine in both groups, either by removing only some parts or all the infected dentine in the deep carious lesion.

  16. Micromorphological Evidence of Neolithic Rondel-like Ditch Infillings. Case Studies from Těšetice-Kyjovice and Kolín, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Lisá, Lenka; Bajer, A.; Válek, D.; Květina, Petr; Šumberová, Radka

    2013-01-01

    Roč. 4, č. 2 (2013), s. 135-146 ISSN 1804-848X R&D Projects: GA ČR(CZ) GAP405/11/1590 Institutional support: RVO:67985831 ; RVO:67985912 Keywords : formation processes * sedimentology * micromorphology * Neolithic rondel structures * STK (Stroked pottery culture) * Lengyel culture * Czech Republic Subject RIV: DB - Geology ; Mineralogy; AC - Archeology, Anthropology, Ethnology (ARU-G) http://www.iansa.eu/papers/IANSA-2013-02-lisa.pdf

  17. Combining Bioactive Multifunctional Dental Composite with PAMAM for Root Dentin Remineralization

    Directory of Open Access Journals (Sweden)

    Shimeng Xiao

    2017-01-01

    Full Text Available Objectives. The objectives of this study were to: (1 develop a bioactive multifunctional composite (BMC via nanoparticles of amorphous calcium phosphate (NACP, 2-methacryloyloxyethyl phosphorylcholine (MPC, dimethylaminohexadecyl methacrylate (DMAHDM and nanoparticles of silver (NAg; and (2 investigate the effects of combined BMC + poly (amido amine (PAMAM on remineralization of demineralized root dentin in a cyclic artificial saliva/lactic acid environment for the first time. Methods. Root dentin specimens were prepared and demineralized with 37% phosphoric acid for 15 s. Four groups were prepared: (1 root dentin control; (2 root dentin with BMC; (3 root dentin with PAMAM; (4 root dentin with BMC + PAMAM. Specimens were treated with a cyclic artificial saliva/lactic acid regimen for 21 days. Calcium (Ca and phosphate (P ion concentrations and acid neutralization were determined. The remineralized root dentin specimens were examined via hardness testing and scanning electron microscopy (SEM. Results. Mechanical properties of BMC were similar to commercial control composites (p = 0.913. BMC had excellent Ca and P ion release and acid-neutralization capability. BMC or PAMAM alone each achieved slight mineral regeneration in demineralized root dentin. The combined BMC + PAMAM induced the greatest root dentin remineralization, and increased the hardness of pre-demineralized root dentin to match that of healthy root dentin (p = 0.521. Significance. The excellent root dentin remineralization effects of BMC + PAMAM were demonstrated for the first time. BMC + PAMAM induced effective and complete root dentin remineralization in an acid challenge environment. The novel BMC + PAMAM method is promising for Class V and other restorations to remineralize and protect tooth structures.

  18. Effects of a Dicalcium and Tetracalcium Phosphate-Based Desensitizer on In Vitro Dentin Permeability.

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    Jianfeng Zhou

    Full Text Available The present study evaluated the effectiveness of a dicalcium and tetracalcium phosphate-based desensitizer in reducing dentin permeability in vitro. Dentin fluid flow was measured before and after treatment of dentin with patent dentinal tubules using 1 or 3 applications of the dicalcium and tetracalcium phosphate containing agent TeethmateTM (TM and comparing the results with two sodium fluoride varnishes VellaTM (VLA and VanishTM (VAN, after storage in artificial saliva for 24 h, 48 h and 7 days. Significant differences were observed among the 4 methods employed for reducing dentin permeability (p < 0.001 and the 3 post-treatment times (p < 0.001. VLA and VAN never achieved 50% permeability reductions consistently in any of the 3 time periods. Only the calcium phosphate-based desensitizer applied for 3 times consistently reduced dentin permeability by 50% after 24 h. When applied once, the permeability reduction of TM increased progressively over the 3 time periods. After 7 days, only one and three applications of the calcium phosphate-based desensitizer consistently reduced dentin permeability by more than 50%. Permeability reductions corresponded well with scanning electron microscopy examination of dentinal tubule orifice occlusion in dentin specimens treated with the agents. Overall, the dicalcium and tetracalcium phosphate-based desensitizer is effective in reducing dentin permeability via a tubule occlusion mechanism. The ability of the agent to reduce dentin permeability renders it to be potentially useful as a clinical dentin desensitizing agent, which has to be confirmed in future clinical studies. By contrast, the two sodium fluoride varnishes are not effective in dentin permeability reduction and should be considered as topical fluoride delivering agents rather than tubular orifice-blocking agents.

  19. Microchemical and structural regular variability of apatites in 'overbuilt' enamel and dentin of human molar teeth

    Energy Technology Data Exchange (ETDEWEB)

    Kuczumow, A., E-mail: kuczon@kul.lublin.pl [Department of Chemistry, Lublin Catholic University, 20-718 Lublin (Poland); Nowak, J. [Department of Chemistry, Lublin Catholic University, 20-718 Lublin (Poland); ChaLas, R. [Department of Conservative Medicine, Lublin Medical University, 20-081 Lublin (Poland)

    2011-10-15

    The aim of a recent paper was to recognize the chemical and structural changes in apatites, which form both the enamel and the dentin of the human tooth. The aim was achieved by scrutinizing the linear elemental profiles along the cross-sections of human molar teeth. Essentially, the task was accomplished with the application of the Electron Probe Microanalysis method and with some additional studies by Micro-Raman spectrometry. All the trends in linear profiles were strictly determined. In the enamel zone they were either increasing or decreasing curves of exponential character. The direction of the investigations was to start with the tooth surface and move towards the dentin-enamel junction (DEJ). The results of the elemental studies were more visible when the detected material was divided, in an arbitrary way, into the prevailing 'core' enamel ({approx}93.5% of the total mass) and the remaining 'overbuilt' enamel. The material in the 'core' enamel was fully stable, with clearly determined chemical and mechanical features. However, the case was totally different in the 'overbuilt enamel', with dynamic changes in the composition. In the 'overbuilt' layer Ca, P, Cl and F profiles present the decaying distribution curves, whereas Mg, Na, K and CO{sub 3}{sup 2-} present the growing ones. Close to the surface of the tooth the mixture of hydroxy-, chlor- and fluor-apatite is formed, which is much more resistant than the rest of the enamel. On passing towards the DEJ, the apatite is enriched with Na, Mg and CO{sub 3}{sup 2-}. In this location, three of six phosphate groups were substituted with carbonate groups. Simultaneously, Mg is associated with the hydroxyl groups around the hexad axis. In this way, the mechanisms of exchange reactions were established. The crystallographic structures were proposed for new phases located close to DEJ. In the dentin zone, the variability of elemental profiles looks different, with

  20. Comparative Evaluation of Efficacy of Iontophoresis with 0.33% Sodium Fluoride Gel and Diode Laser Alone on Occlusion of Dentinal Tubules.

    Science.gov (United States)

    Patil, Anup Raghunath; Varma, Siddhartha; Suragimath, Girish; Abbayya, Keshava; Zope, Sameer Anil; Kale, Vishwajeet

    2017-08-01

    Dentinal Hypersensitivity (DH) is one of the most commonly encountered clinical problems. Literature reveals no specific therapy to satisfactorily eliminate dentinal hypersensitivity. The aim of this study was to assess and compare the efficacy of iontophoresis with 0.33% Sodium Fluoride (NaF) gel and diode laser alone in dentinal tubule occlusion. This in vitro study included 20 teeth with intact root surfaces unaltered by extraction procedure for specimen preparation. Each tooth was cleaned, air dried and cut into three sections. Total 60 sections were prepared (30 longitudinal and 30 transverse sections), which were acid etched. In control group, no treatment was carried. In iontophoresis treatment group, samples were inserted into a foam tray containing 0.33 % NaF Gel and subjected to 1.5 mA output current for three minutes. In laser treatment group, specimens were lased with 980 nm diode laser at 0.5 W/PW (62.2J /cm 2 ) in a noncontact mode for 30 seconds. Specimens were evaluated under Scanning Electron Microscope (SEM) at 10KV to 20KV under x 2000, x5000 magnification for surface characteristics and patency of dentinal tubules. Total number of tubules visible, open, completely and partially occluded were recorded in each microphotograph and compared. On comparison, laser group showed the least number of open tubules i.e., 130 (31.1%) followed by iontophoresis group, 155 (51.32%) and control group 417 (100%). Diode laser application provided better results as compared to iontophoresis on occlusion of dentinal tubules. Hence, it can be used to treat the patients with DH.

  1. Effects of solvent volatilization time on the bond strength of etch-and-rinse adhesive to dentin using conventional or deproteinization bonding techniques.

    Science.gov (United States)

    de Sousa Júnior, José Aginaldo; Carregosa Santana, Márcia Luciana; de Figueiredo, Fabricio Eneas Diniz; Faria-E-Silva, André Luis

    2015-08-01

    This study determined the effect of the air-stream application time and the bonding technique on the dentin bond strength of adhesives with different solvents. Furthermore, the content and volatilization rate of the solvents contained in the adhesives were also evaluated. Three adhesive systems with different solvents (Stae, SDI, acetone; XP Bond, Dentsply De Trey, butanol; Ambar, FGM, ethanol) were evaluated. The concentrations and evaporation rates of each adhesive were measured using an analytical balance. After acid-etching and rinsing, medium occlusal dentin surfaces of human molars were kept moist (conventional) or were treated with 10% sodium hypochlorite for deproteinization. After applying adhesives over the dentin, slight air-stream was applied for 10, 30 or 60 sec. Composite cylinders were built up and submitted to shear testing. The data were submitted to ANOVA and Tukey's test (α = 0.05). Stae showed the highest solvent content and Ambar the lowest. Acetone presented the highest evaporation rate, followed by butanol. Shear bond strengths were significantly affected only by the factors of 'adhesive' and 'bonding technique' (p Stae showed the lowest bond strength values (p < 0.05), while no significant difference was observed between XP Bond and Ambar. Despite the differences in content and evaporation rate of the solvents, the duration of air-stream application did not affect the bond strength to dentin irrespective of the bonding technique.

  2. Incidence of apical root cracks and apical dentinal detachments after canal preparation with hand and rotary files at different instrumentation lengths.

    Science.gov (United States)

    Liu, Rui; Kaiwar, Anjali; Shemesh, Hagay; Wesselink, Paul R; Hou, Benxiang; Wu, Min-Kai

    2013-01-01

    The aim of this study was to compare the incidence of apical root cracks and dentinal detachments after canal preparation with hand and rotary files at different instrumentation lengths. Two hundred forty mandibular incisors were mounted in resin blocks with simulated periodontal ligaments, and the apex was exposed. The root canals were instrumented with rotary and hand files, namely K3, ProTaper, and nickel-titanium Flex K files to the major apical foramen (AF), short AF, or beyond AF. Digital images of the apical surface of every tooth were taken during the apical enlargement at each file change. Development of dentinal defects was determined by comparing these images with the baseline image. Multinomial logistic regression test was performed to identify influencing factors. Apical crack developed in 1 of 80 teeth (1.3%) with hand files and 31 of 160 teeth (19.4%) with rotary files. Apical dentinal detachment developed in 2 of 80 teeth (2.5%) with hand files and 35 of 160 teeth (21.9%) with rotary files. Instrumentation with rotary files terminated 2 mm short of AF and did not cause any cracks. Significantly less cracks and detachments occurred when instrumentation with rotary files was terminated short of AF, as compared with that terminated at or beyond AF (P hand instruments; instrumentation short of AF reduced the risk of dentinal defects. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. Anatomical and micro-morphological analysis of the fruit and vegetative organs of Inula oculus-christi L. in the Pannonian part of Serbia

    Directory of Open Access Journals (Sweden)

    Karanović Dunja S.

    2016-01-01

    Full Text Available Inula oculus-christi L. is a perennial plant, 20-60 cm high, growing in south-east Europe, central and southern Russia and some parts of Asia. It belongs to Pontic-Pannonian floristic element. In Pannonian part of Serbia this species is extremely rare, with very few recently confirmed literature and herbarium data. According to the field data for the period from 2013 to 2015, only one population of this species was recorded in Pannonian part of Serbia, on the site of Rimski Šanac, which is threatened by anthropogenic activities. Furthermore, anatomical and micro-morphological features of I. oculus-christi have not been documented so far. Therefore, in order to get better knowledge of the biology this species, as well as on the basis of the abovementioned, its anatomical and micro-morphological characteristics were investigated. Cross sections of the leaf, stem, rhizome and fruit were obtained using cryotechnique procedure by Leica CM 1850 cryostat. Using a light microscopy, detailed descriptions of anatomical characteristics of the analysed organs were given. The scanning electron microscopy revealed specific qualitative features of leaf and fruit that characterize the species. Obtained data may be useful in determination of this species and represent the valuable contribution to its micro-morphological and anatomical differentiation from other congeneric and related species. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173002

  4. Sealing ability of a new calcium silicate based material as a dentin substitute in class II sandwich restorations: An in vitro study

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    Raji Viola Solomon

    2014-01-01

    Full Text Available Background: Class ll sandwich restorations are routinely performed where conventional Glass ionomer cement (GIC or Resin-modified GIC (RMGIC is used as a base or dentin substitute and a light curing composite resin restorative material is used as an enamel substitute. Various authors have evaluated the microleakage of composite resin restorations where glass ionomer cement has been used as a base in class II sandwich restorations, but a literature survey reveals limited studies on the microleakage analysis of similar restorations with biodentine as a dentin substitute, as an alternative to glass ionomer cement. The aim of this study is: To evaluate the marginal sealing efficacy of a new calcium-silicate-based material (Biodentine as a dentin substitute, at the cervical margins, in posterior class II sandwich restorations.To compare and evaluate the microleakage at the biodentine/composite interface with the microleakage at the resin-modified GIC/composite interface, in posterior class II open sandwich restorations. To compare the efficacy between a water-based etch and rinse adhesive (Scotch bond multipurpose and an acetone-based etch and rinse adhesive (Prime and bond NT, when bonding biodentine to the composite. To evaluate the enamel, dentin, and interfacial microleakage at the composite and biodentine/RMGIC interfaces. Materials and Methods: Fifty class II cavities were prepared on the mesial and distal surfaces of 25 extracted human maxillary third molars, which were randomly divided into five groups of ten cavities each: (G1 Biodentine group, (G2 Fuji II LC GIC group, (G3 Biodentine as a base + prime and bond NT + Tetric N-Ceram composite, (G4 Biodentine + scotchbond multi-purpose + Tetric N-Ceram composite, (G5 Fuji II LC as a base + prime and bond NT+ Tetric-N Ceram composite. The samples were then subjected to thermocycling, 2500× (5°C to 55°C, followed by the dye penetration test. Scores are given from 0 to 3 based on the depth of

  5. Curing mode affects bond strength of adhesively luted composite CAD/CAM restorations to dentin.

    Science.gov (United States)

    Lührs, Anne-Katrin; Pongprueksa, Pong; De Munck, Jan; Geurtsen, Werner; Van Meerbeek, Bart

    2014-03-01

    To determine the effect of curing mode and restoration-surface pre-treatment on the micro-tensile bond strength (μTBS) to dentin. Sandblasted CAD/CAM composite blocks (LAVA Ultimate, 3M ESPE) were cemented to bur-cut dentin using either the etch & rinse composite cement Nexus 3 ('NX3', Kerr) with Optibond XTR ('XTR', Kerr), or the self-etch composite cement RelyX Ultimate ('RXU', 3M ESPE) with Scotchbond Universal ('SBU', 3M ESPE). All experimental groups included different 'curing modes' (light-curing of adhesive and cement ('LL'), light-curing of adhesive and auto-cure of cement ('LA'), co-cure of adhesive through light-curing of cement ('AL'), or complete auto-cure ('AA')) and different 'restoration-surface pre-treatments' of the composite block (NX3: either a silane primer (Kerr), or the XTR adhesive; RXU: either silane primer (RelyX Ceramic Primer, 3M ESPE) and SBU, or solely SBU). After water-storage (7 days, 37°C), the μTBS was measured. Additionally, the degree of conversion (DC) of both cements was measured after 10min and after 1 week, either auto-cured (21°C/37°C) or light-cured (directly/through 3-mm CAD/CAM composite). The linear mixed-effects model (α=0.05) revealed a significant influence of the factors 'curing mode' and 'composite cement', and a less significant effect of the factor 'restoration-surface pre-treatment'. Light-curing 'LL' revealed the highest μTBS, which decreased significantly for all other curing modes. For curing modes 'AA' and 'AL', the lowest μTBS and a high percentage of pre-testing failures were reported. Overall, DC increased with light-curing and incubation time. The curing mode is decisive for the bonding effectiveness of adhesively luted composite CAD/CAM restorations to dentin. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Mineral Apposition Rates in Coronal Dentine of Mandibular First Molars in Soay Sheep: Results of a Fluorochrome Labeling Study.

    Science.gov (United States)

    Kahle, Patricia; Witzel, Carsten; Kierdorf, Uwe; Frölich, Kai; Kierdorf, Horst

    2018-05-01

    We studied the spatio-temporal variation of mineral apposition rate (MAR) in postnatally formed coronal dentine of mandibular first molars from Soay sheep repeatedly injected with different fluorochromes. MAR declined along the cuspal to cervical crown axis, and from early to late formed dentine, that is, from the dentine at the enamel-dentine-junction (EDJ) to the dentine adjacent to the dentine-pulp-interface (DPI). Highest mean MARs (about 21 µm/day) were recorded in cuspal dentine formed in the period of 28-42 days after birth. Lowest values (distributions in sheep dentine aimed at assessing temporal variation of incorporation into forming dentine. Such data are useful in a variety of contexts, including, for example, the exposure to pollutants and the reconstruction of husbandry practices or feeding regimes. Anat Rec, 301:902-912, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Micr