WorldWideScience

Sample records for pulp chamber dentin

  1. Bond durability of contemporary adhesive systems to pulp chamber dentin.

    Science.gov (United States)

    Ayar, Muhammet Kerim

    2015-12-01

    Objective: The purpose of this study was to evaluate long-term bond strengths of dentin adhesive systems, which include one-step self-etch adhesive systems (Optibond All-in-one, Kerr; Adper Prompt L-POP, 3 M ESPE), a three-step etch-and-rinse adhesive (Optibond FL, Kerr) and two-step self-etch adhesive (AdheSE Bond, Ivoclar), applied to pulp chamber dentin surfaces after 12-month water storage by using microtensile bond strength (µTBS) test. Materials and methods: Dentin adhesive systems were applied to unprepared pulp chamber dentin surfaces according to manufacturer's directions, respectively (n = 5). After applying adhesive systems, composite buildups were done incrementally. Bond strengths to pulp chamber dentin surfaces were determined using µTBS test after water storage for 24 h and 12 month. Kruskal-Wallis analysis and Mann-Whitney U-test for pairwise comparisons were used to determine statistical differences in µTBS between the groups at a significance level of 5%. Results: There were no significant differences in µTBS between storage periods for tested adhesives regardless adhesive class. Conclusion: Bond durability of tested adhesive systems, including one-bottle self-etch adhesives with pulp chamber dentin surfaces, may be considered stable after 12-month water storage. Therefore, one-step self-etch, also called "user-friendly" adhesives may perform and traditional three-step etch-and-rinse adhesives in the long-term when used for bonding to pulp chamber dentin surfaces.

  2. Regional bond strengths of adhesive resins to pulp chamber dentin.

    Science.gov (United States)

    Belli, S; Zhang, Y; Pereira, P N; Ozer, F; Pashley, D H

    2001-08-01

    Microleakage of oral microorganisms, which can occur due to the lack of sealing ability of permanent restorative materials, may cause failure of root canal treatments. Although a great deal of research has been done on sealing enamel and coronal dentin with resins, little research has been done on the adhesion of resins to the walls of pulp chambers. The purpose of this study was to evaluate regional bond strengths of two adhesive systems to the walls of pulp chambers. A section was made horizontally through the middle of the pulp chamber of extracted human third molars to divide the chamber into upper and lower halves. The pulp tissue was removed and the tooth segments were then divided into treatment subgroups. The pulp chambers were bonded with C&B Metabond (Parkell) or One-Step (Bisco), with or without 5% NaOCI pretreatment. The microtensile bond strengths of these resins to four different pulp chamber regions (bottom, wall, roof, and pulp horn areas) were then measured using an Instron machine. The data were expressed in MPa and were analyzed by a three-way ANOVA. Statistically significant differences were found among the test groups (p < 0.001). One-Step produced higher bond strengths to all pulp chamber regions except the floor, compared with C&B Metabond. The results indicated that high bond strengths can be achieved between adhesive resins and the various regions of the pulp chamber. This should permit the use of a thick layer of unfilled resin along the floor of the pulp chamber and over the canal orifices as a secondary protective seal after finishing root canal therapy.

  3. Micro-tensile bond strength of adhesives to pulp chamber dentin after irrigation with Ethylenediaminetetraacetic acid

    OpenAIRE

    Ç Barutcigil; Arslan, H.; Özcan, E.; O T Harorli

    2012-01-01

    Aim: The aim of this study was to evaluate the influence of different concentrations of Ethylenediaminetetraacetic acid (EDTA) solution on adhesion, that is, the bond strength of the different adhesive systems, to the pulp chamber dentin. Materials and Methods: Recently extracted, sound, human, third molars were cut horizontally to expose the pulp horn. The roof of the pulp chamber and pulp tissue was removed. The teeth were then divided into five main groups. The teeth in each group were ...

  4. Temperature changes in the pulp chamber during dentin ablation with Er:YAG laser

    Science.gov (United States)

    Zhang, Xianzeng; Zhao, Haibin; Zhan, Zhenlin; Guo, Wenqing; Xie, Shusen

    2012-12-01

    To examine the temperature changes in the pulp chamber during cavity preparation in dentin with the Er:YAG laser (2940 nm), a total 20 intact premolars teeth were divided into 4 groups for dentin ablation with different radiant exposures at 4Hz and 8Hz with and without water spray. A K-type thermocouple was used to monitor the temperature changes in pulp chamber during laser treatment. The total time of irradiation was 70 sec. the water spray rate was 3 mL/min. It showed that maximum temperature rise increases with the increasing of radiant exposure and pulse repetition rate and the additional water cooling during laser ablation can significantly reduce the temperature rise in pulp chamber which will benefit to avoid or reduce thermal damage to tooth structure and dental pulp. The highest rise of temperature in the pulp was achieved with 20 J/cm2 and 8 Hz (19.83°C ). For all sample without water spray, the rise of temperature was exceed 5 °C . In contrast, with water spray, the temperature rise in the pulp can be firmly controlled under 1°C. The results also indicated that ablation rate and efficiency can be enhanced by increasing the incident radiant exposure and pulse repetition rate, which simultaneously producing more heat accumulation in dental tissue and causing thermal damage to dental tissue. By applying an additional water spray, thermal damage can be significantly reduced in clinical application.

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

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    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.

  6. Resin Bonding of Self-Etch Adhesives to Bovine Dentin Bleached from Pulp Chamber

    Science.gov (United States)

    Haruyama, Akiko; Kato, Junji; Takemoto, Shinji; Oda, Yutaka; Kawada, Eiji; Takahashi, Toshiyuki; Furusawa, Masahiro

    2016-01-01

    This study evaluated the microtensile bond strength (μTBS) of 1-step self-etch adhesives (1-SEAs) and 2-step self-etch adhesives (2-SEAs) to pulp chamber dentin immediately after bleaching with 2 types of common bleaching techniques. Pulp chamber dentin of bovine teeth was bleached using 30% hydrogen peroxide (H2O2) solution with quartz-tungsten-halogen light-curing unit (Group 1) and 3.5% H2O2-containing titanium dioxide (TiO2) (Pyrenees®) activated with 405-nm violet diode laser for 15 min (Group 2). Unbleached specimens were placed in distilled water for 15 min and used as controls. After treatment, dentin was bonded with resin composite using 1-SEA or 2-SEA and stored in water at 37°C for 24 h. Each specimen was sectioned and trimmed to an hourglass-shape and μTBS was measured. Fractured specimens were examined under a scanning electron microscope to determine fracture modes. All specimens in Group 1 failed before proper bonding tests. In Group 2, the μTBS of 2-SEA was significantly greater (with no failed specimens) than 1-SEA (where 21 out of 36 failed). These results indicate that 2-SEA is a better adhesive system than 1-SEA on bleached dentin. Our results also demonstrated that application of H2O2 significantly decreases bond strength of resin to dentin; however, in the case of nonvital tooth bleaching, Pyrenees® is a better alternative to the conventional 30% H2O2 bleaching. PMID:27747220

  7. Resin Bonding of Self-Etch Adhesives to Bovine Dentin Bleached from Pulp Chamber.

    Science.gov (United States)

    Haruyama, Akiko; Kameyama, Atsushi; Kato, Junji; Takemoto, Shinji; Oda, Yutaka; Kawada, Eiji; Takahashi, Toshiyuki; Furusawa, Masahiro

    2016-01-01

    This study evaluated the microtensile bond strength (μTBS) of 1-step self-etch adhesives (1-SEAs) and 2-step self-etch adhesives (2-SEAs) to pulp chamber dentin immediately after bleaching with 2 types of common bleaching techniques. Pulp chamber dentin of bovine teeth was bleached using 30% hydrogen peroxide (H2O2) solution with quartz-tungsten-halogen light-curing unit (Group 1) and 3.5% H2O2-containing titanium dioxide (TiO2) (Pyrenees®) activated with 405-nm violet diode laser for 15 min (Group 2). Unbleached specimens were placed in distilled water for 15 min and used as controls. After treatment, dentin was bonded with resin composite using 1-SEA or 2-SEA and stored in water at 37°C for 24 h. Each specimen was sectioned and trimmed to an hourglass-shape and μTBS was measured. Fractured specimens were examined under a scanning electron microscope to determine fracture modes. All specimens in Group 1 failed before proper bonding tests. In Group 2, the μTBS of 2-SEA was significantly greater (with no failed specimens) than 1-SEA (where 21 out of 36 failed). These results indicate that 2-SEA is a better adhesive system than 1-SEA on bleached dentin. Our results also demonstrated that application of H2O2 significantly decreases bond strength of resin to dentin; however, in the case of nonvital tooth bleaching, Pyrenees® is a better alternative to the conventional 30% H2O2 bleaching.

  8. Resin Bonding of Self-Etch Adhesives to Bovine Dentin Bleached from Pulp Chamber

    Directory of Open Access Journals (Sweden)

    Akiko Haruyama

    2016-01-01

    Full Text Available This study evaluated the microtensile bond strength (μTBS of 1-step self-etch adhesives (1-SEAs and 2-step self-etch adhesives (2-SEAs to pulp chamber dentin immediately after bleaching with 2 types of common bleaching techniques. Pulp chamber dentin of bovine teeth was bleached using 30% hydrogen peroxide (H2O2 solution with quartz-tungsten-halogen light-curing unit (Group 1 and 3.5% H2O2-containing titanium dioxide (TiO2 (Pyrenees® activated with 405-nm violet diode laser for 15 min (Group 2. Unbleached specimens were placed in distilled water for 15 min and used as controls. After treatment, dentin was bonded with resin composite using 1-SEA or 2-SEA and stored in water at 37°C for 24 h. Each specimen was sectioned and trimmed to an hourglass-shape and μTBS was measured. Fractured specimens were examined under a scanning electron microscope to determine fracture modes. All specimens in Group 1 failed before proper bonding tests. In Group 2, the μTBS of 2-SEA was significantly greater (with no failed specimens than 1-SEA (where 21 out of 36 failed. These results indicate that 2-SEA is a better adhesive system than 1-SEA on bleached dentin. Our results also demonstrated that application of H2O2 significantly decreases bond strength of resin to dentin; however, in the case of nonvital tooth bleaching, Pyrenees® is a better alternative to the conventional 30% H2O2 bleaching.

  9. Micro-tensile bond strength of adhesives to pulp chamber dentin after irrigation with Ethylenediaminetetraacetic acid

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    Ç Barutcigil

    2012-01-01

    Conclusion: This study showed that EDTA irrigation can affect the bond strength of adhesive systems on pulp chamber lateral walls. Clinically, low EDTA concentrations can be recommended if self-etch adhesives have been selected.

  10. Effect of different gutta-percha solvents on the microtensile bond strength of various adhesive systems to pulp chamber dentin.

    Science.gov (United States)

    Demırbuga, Sezer; Pala, Kanşad; Topçuoğlu, Hüseyin Sinan; Çayabatmaz, Muhammed; Topçuoğlu, Gamze; Uçar, Ebru Nur

    2017-03-01

    The aim of this study was to evaluate the effect of different endodontic solvents on the microtensile bond strength (μTBS) of various adhesives to pulp chamber dentin. A total of 120 human third molars were selected. Canals were prepared with the ProTaper Universal system and obturated. The access cavities were then restored with resin composite. After 1 week, a retreatment procedure was applied as follows: control, no solvent was applied to the pulp chamber and experimental groups, three different solvents (chloroform, eucalyptol, and orange oil) were applied to the pulp chamber for 2 min. The canal filling was removed and calcium hydroxide (Ca[OH]2) was placed into the canals. After 7 days, the Ca(OH)2 was removed from the canals and the canals were re-obturated. Teeth were then divided into three subgroups according to the adhesive used. The samples were restored with a nanohybrid resin composite using three different adhesives: Clearfil SE Bond (CSE), Adper Easy One (AEO), and Single Bond 2 (SB2). The samples were aged with thermocycling. Teeth were sectioned, and a total of 20 dentin sticks were obtained for each subgroup. μTBS testing was then performed. The debonded surfaces were evaluated using scanning electron microscopy (SEM) analysis. Data were analyzed using two-way ANOVA and Tukey's post hoc tests. Chloroform showed statistically lower mean μTBS values (14 ± 7.2 MPa) than control group did (19.2 ± 6.1 MPa) (p  0.05). Chloroform showed significantly lower bond strength for all adhesives (p adhesive systems significantly (p > 0.05), eucalyptol reduced the μTBS values of all the groups, but the results were only statistically significant for SB2 (p  0.05). According to the SEM analysis of the debonded surfaces, adhesive failures were the most common type in all the groups, followed by mixed failures. While chloroform reduced the mean bond strength of the adhesive resins, orange oil did not affect the bond strength of the adhesives

  11. Comparative Evaluation of Microshear Bond Strength of 5th, 6th and 7th Generation Bonding Agents to Coronal Dentin Versus Dentin at Floor of Pulp Chamber: An In vitro Study

    OpenAIRE

    Deepa, Velagala Lakshmi; Damaraju, Bhargavi; Priyadharsini, Bollu Indira; Subbarao, Vummidisetti V; Raju, K Rama Krishna

    2014-01-01

    Background: Lack of seal and adhesion between the final restoration and tooth structure adversely affects the results of root canal treatment. Lots of adhesive bonding agents are marketed to overcome this deficiency and achieve successful restoration. So the study compares and evaluates the micro shear bond strength of coronal dentin and pulp chamber dentin using three different generation dentin bonding systems and to know clinical efficiency for clinical use. Materials and Methods: Differen...

  12. Effect of titanium dioxide and 3.5% hydrogen peroxide with 405-nm diode laser irradiation on bonding of resin to pulp chamber dentin

    Science.gov (United States)

    Haruyama, A.; Kato, J.; Kameyama, A.; Hirai, Y.; Oda, Y.

    2010-04-01

    This study was conducted to determine the effect of a 3.5% hydrogen peroxide solution containing titanium dioxide on bonding of resin to pulp chamber dentin. Extracted bovine anterior teeth were allocated to three groups of ten teeth each. The coronal labial pulp chamber dentin was exposed and bleached with 3.5% hydrogen peroxide with titanium dioxide with 405-nm diode laser irradiation for 15 min (Group 1); 30% hydrogen peroxide with halogen lamp irradiation for 15 min (Group 2); and distilled water for 15 min (Group 3). After bleaching, the pulp chamber dentin was prepared for composite resin bonding and the interface between the resin and dentin was observed by scanning electron microscopy. The microtensile bond strength (μTBS) and failure patterns were determined. The μTBS values (mean ± SD) were: 17.28 ± 5.79 MPa ( n = 36), 0 MPa, and 26.50 ± 9.83 MPa ( n = 36) in Groups 1, 2, and 3, respectively. The μTBS in Group 3 was significantly higher than that in Group 1 ( P < 0.05). Hybrid layers and resin tags were clearly observed at the interface in Groups 1 and 3, but not in Group 2. Adhesive failure was mainly observed in Group 1, whereas dentin failure was the main failure pattern in Group 3.

  13. Comparative Evaluation of Microshear Bond Strength of 5(th), 6(th) and 7(th) Generation Bonding Agents to Coronal Dentin Versus Dentin at Floor of Pulp Chamber: An In vitro Study.

    Science.gov (United States)

    Deepa, Velagala Lakshmi; Damaraju, Bhargavi; Priyadharsini, Bollu Indira; Subbarao, Vummidisetti V; Raju, K Rama Krishna

    2014-09-01

    Lack of seal and adhesion between the final restoration and tooth structure adversely affects the results of root canal treatment. Lots of adhesive bonding agents are marketed to overcome this deficiency and achieve successful restoration. So the study compares and evaluates the micro shear bond strength of coronal dentin and pulp chamber dentin using three different generation dentin bonding systems and to know clinical efficiency for clinical use. DIFFERENT GENERATION DENTIN BONDING SYSTEMS USED WERE: (1) One bottle total etch system (XP Bond-5(th) generation), (2) Two-step self-etch system (Clearfil SE Bond-6(th) generation) and (3) All-in-one system (G Bond-7(th) generation). Thirty human mandibular molars were collected out of which sixty samples were prepared by sectioning each tooth into coronal dentin and pulpal floor dentin. They were divided into two major groups. Group I: 30 Coronal dentin samples. Group II:30 Pulpal floor dentin samples. Both the groups were further subdivided depending on the bonding agent used. Subgroup Ia:XP Bond, Subgroup Ib:Clearfil SE Bond, Subgroup Ic:G Bond, Subgroup IIa:XP Bond, Subgroup IIb:Clearfil SE Bond, Subgroup IIc:G Bond. Resin composite was bonded to these samples and tested for micro-shear bond strength. The mean bond strengths and standard deviations were calculated and analyzed using one-way ANOVA test and Student's t-test (unpaired) and honestly significant difference post-hoc tests. Coronal dentin showed higher values of micro shear bond strength than the pulpal floor dentin. All-in-one system (G Bond) showed least bond strength values to both the regions coronal dentin and pulpal floor dentin. Factors affecting the shear bond strength are dependent on material (adhesive system), substrate depth and adhesive/depth interaction. Hence composition and substrate treatment should be considered for good adhesive. Chemical composition of adhesive system determines clinical successes.

  14. Effects of distance from the pulp and thickness on the hydraulic conductance of human radicular dentin.

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    Fogel, H M; Marshall, F J; Pashley, D H

    1988-11-01

    The purposes of this study were: (1) to measure the effect of distance from the pulp on the hydraulic conductance of human radicular dentin; (2) to determine the influence of dentin thickness on the rates of fluid flow; and (3) to attempt to correlate dentinal tubule densities and diameters with root dentin hydraulic conductance. Dentin slabs prepared from extracted, unerupted, human third molar teeth were placed in a split-chamber device to permit quantitation of fluid filtration rate (hydraulic conductance). In the SEM portion of the study, dentinal tubule numbers and diameters were recorded. The results indicated that radicular dentin hydraulic conductance decreased with distance from the pulp and with increasing dentin thickness. Tubule density and diameter correlated well with the measured hydraulic conductances. The relatively low hydraulic conductance of outer root dentin makes it a significant barrier to fluid movement across root structure.

  15. In vitro penetration of bleaching agents into the pulp chamber

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Valera, M C; Mancini, M N G

    2004-01-01

    To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures.......To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures....

  16. EDTA conditioning of dentine promotes adhesion, migration and differentiation of dental pulp stem cells.

    Science.gov (United States)

    Galler, K M; Widbiller, M; Buchalla, W; Eidt, A; Hiller, K-A; Hoffer, P C; Schmalz, G

    2016-06-01

    To evaluate the effect of dentine conditioning on migration, adhesion and differentiation of dental pulp stem cells. Dentine discs prepared from extracted human molars were pre-treated with EDTA (10%), NaOCl (5.25%) or H2 O. Migration of dental pulp stem cells towards pre-treated dentine after 24 and 48 h was assessed in a modified Boyden chamber assay. Cell adhesion was evaluated indirectly by measuring cell viability. Expression of mineralization-associated genes (COL1A1, ALP, BSP, DSPP, RUNX2) in cells cultured on pre-treated dentine for 7 days was determined by RT-qPCR. Nonparametric statistical analysis was performed for cell migration and cell viability data to compare different groups and time-points (Mann-Whitney U-test, α = 0.05). Treatment of dentine with H2 O or EDTA allowed for cell attachment, which was prohibited by NaOCl with statistical significance (P = 0.000). Furthermore, EDTA conditioning induced cell migration towards dentine. The expression of mineralization-associated genes was increased in dental pulp cells cultured on dentine after EDTA conditioning compared to H2 O-pre-treated dentine discs. EDTA conditioning of dentine promoted the adhesion, migration and differentiation of dental pulp stem cells towards or onto dentine. A pre-treatment with EDTA as the final step of an irrigation protocol for regenerative endodontic procedures has the potential to act favourably on new tissue formation within the root canal. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  17. Induction of Reparative Dentin Formation on Exposed Dental Pulp by Dentin Phosphophoryn/Collagen Composite

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    Toshiyuki Koike

    2014-01-01

    Full Text Available The ultimate goal of vital pulp therapy is to regenerate rapidly dentin possessing an excellent quality using a biocompatible, bioactive agent. Dentin phosphophoryn (DPP, the most abundant noncollagenous polyanionic protein in dentin, cross-linked to atelocollagen fibrils was applied to direct pulp capping in rats. After 1, 2, and 3 weeks, the teeth applied were examined on the induction of reparative dentin formation and the response of pulp tissue, compared to calcium hydroxide-based agent conventionally used. The reparative dentin formation induced by DPP/collagen composite was more rapid than by calcium hydroxide. In the morphometrical analysis, the formation rate of reparative dentin by DPP/collagen composite was approximately the same as that by calcium hydroxide at 3 weeks. Nevertheless, the compactness of reparative dentin formed by DPP/collagen composite was much superior to what resulted from calcium hydroxide. Also, DPP/collagen composite showed high covering ability of exposed pulp. Moreover, DPP/collagen composite led only to slight pulp inflammation at the beginning whereas calcium hydroxide formed necrotic layer adjacent to the material and induced severe inflammation in pulp tissue at 1 week. The present study demonstrates a potential for DPP/collagen composite as a rapid biocompatible inducer for the formation of reparative dentin of excellent quality in rats.

  18. Mesenchymal dental pulp cells attenuate dentin resorption in homeostasis.

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    Zheng, Y; Chen, M; He, L; Marão, H F; Sun, D M; Zhou, J; Kim, S G; Song, S; Wang, S L; Mao, J J

    2015-06-01

    Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone-derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal

  19. Pulp-dentin Regeneration: Current State and Future Prospects.

    Science.gov (United States)

    Cao, Y; Song, M; Kim, E; Shon, W; Chugal, N; Bogen, G; Lin, L; Kim, R H; Park, N-H; Kang, M K

    2015-11-01

    The goal of regenerative endodontics is to reinstate normal pulp function in necrotic and infected teeth that would result in reestablishment of protective functions, including innate pulp immunity, pulp repair through mineralization, and pulp sensibility. In the unique microenvironment of the dental pulp, the triad of tissue engineering would require infection control, biomaterials, and stem cells. Although revascularization is successful in resolving apical periodontitis, multiple studies suggest that it alone does not support pulp-dentin regeneration. More recently, cell-based approaches in endodontic regeneration based on pulpal mesenchymal stem cells (MSCs) have demonstrated promising results in terms of pulp-dentin regeneration in vivo through autologous transplantation. Although pulpal regeneration requires the cell-based approach, several challenges in clinical translation must be overcome-including aging-associated phenotypic changes in pulpal MSCs, availability of tissue sources, and safety and regulation involved with expansion of MSCs in laboratories. Allotransplantation of MSCs may alleviate some of these obstacles, although the long-term stability of MSCs and efficacy in pulp-dentin regeneration demand further investigation. For an alternative source of MSCs, our laboratory developed induced MSCs (iMSCs) from primary human keratinocytes through epithelial-mesenchymal transition by modulating the epithelial plasticity genes. Initially, we showed that overexpression of ΔNp63α, a major isoform of the p63 gene, led to epithelial-mesenchymal transition and acquisition of stem characteristics. More recently, iMSCs were generated by transient knockdown of all p63 isoforms through siRNA, further simplifying the protocol and resolving the potential safety issues of viral vectors. These cells may be useful for patients who lack tissue sources for endogenous MSCs. Further research will elucidate the level of potency of these iMSCs and assess their

  20. In Vivo Experiments with Dental Pulp Stem Cells for Pulp-Dentin Complex Regeneration

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    Sunil Kim

    2015-01-01

    Full Text Available In recent years, many studies have examined the pulp-dentin complex regeneration with DPSCs. While it is important to perform research on cells, scaffolds, and growth factors, it is also critical to develop animal models for preclinical trials. The development of a reproducible animal model of transplantation is essential for obtaining precise and accurate data in vivo. The efficacy of pulp regeneration should be assessed qualitatively and quantitatively using animal models. This review article sought to introduce in vivo experiments that have evaluated the potential of dental pulp stem cells for pulp-dentin complex regeneration. According to a review of various researches about DPSCs, the majority of studies have used subcutaneous mouse and dog teeth for animal models. There is no way to know which animal model will reproduce the clinical environment. If an animal model is developed which is easier to use and is useful in more situations than the currently popular models, it will be a substantial aid to studies examining pulp-dentin complex regeneration.

  1. Adhesive sealing of the pulp chamber.

    Science.gov (United States)

    Belli, S; Zhang, Y; Pereira, P N; Pashley, D H

    2001-08-01

    The purpose of this in vitro study was to evaluate quantitatively the ability of four different filling materials to seal the orifices of root canals as a secondary seal after root canal therapy. Forty extracted human molar teeth were used. The top of pulp chambers and distal halves of the roots were removed using an Isomet saw. The canal orifices were temporarily sealed with a gutta-percha master cone without sealer. The pulp chambers were then treated with a self-etching primer adhesive system (Clearfil SE Bond), a wet bonding system (One-Step), a 4-methacryloyloxyethyl trimellitate anhydride adhesive system (C&B Metabond), or a reinforced zinc oxide-eugenol (IRM). The specimens were randomly divided into four groups of 10 each. A fluid filtration method was used for quantitative evaluation of leakage. Measurements of fluid movement were made at 2-min intervals for 8 min. The quality of the seal of each specimen was measured by fluid filtration immediately and after 1 day, 1 wk, and 1 month. Even after 1 month the resins showed an excellent seal. Zinc oxide-eugenol had significantly more leakage when compared with the resin systems (p < 0.05). Adhesive resins should be considered as a secondary seal to prevent intraorifice microleakage.

  2. Cryopreserved dentin matrix as a scaffold material for dentin-pulp tissue regeneration.

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    Jiao, Liang; Xie, Li; Yang, Bo; Yu, Mei; Jiang, Zongting; Feng, Lian; Guo, Weihua; Tian, Weidong

    2014-06-01

    Cryopreservation has been identified as an efficient approach to preserve tissue engineered products for a long term. Our prior studies have suggested that the treated dentin matrix (TDM) could be an ideal bioactive scaffold for dental tissue regeneration. In this study, we hypothesize that the cryopreservation could effectively maintain the survival and viability of dentinogenesis-related proteins of TDM and the cryopreserved dentin matrix (CDM) would provide the suitable biological scaffold and inductive microenvironment for the regeneration of dentin-pulp like tissue. CDM-3 and CDM-6 were prepared by cryopreserving TDM in liquid nitrogen (-196 °C) with cryoprotectant for 3 months and 6 months, respectively. Various biological characteristics of CDM, including mechanical properties, cell proliferation, and odontogenesis ability, were investigated. To further evaluate the inductive capacity of CDM, human dental follicle cells were encapsulated within CDM, and implanted the scaffold into a mouse model for 8 weeks, and the grafts were harvested and assessed histologically. The CDM showed superior mechanical properties than TDM. Compared to TDM, CDM can release more dentinogenesis-related proteins due to the larger pore diameter. Cell proliferation with the addition of CDM extract liquid was similar to that of TDM in the first five days. Human dental follicle cells, under the effect of CDM extract liquid, highly expressed bone sialoprotein, collagen-1, alkaline phosphatase, indicating that CDM, regarded as the inductive microenvironment, plays an important role in odontogenesis. Most importantly, in vivo, CDM could induce dental follicle cells to regenerate new dentin-pulp like tissues, such as dentinal tubules, predentin, collagen fibers, nerves, and blood vessels which were positive for dentin sialophosphoprotein, dental matrix protein-1, Tubulin, and collagen-1. In conclusion, CDM is an ideal biological scaffold material for human dentin-pulp like tissue

  3. Local Regeneration of Dentin-Pulp Complex Using Controlled Release of FGF-2 and Naturally Derived Sponge-Like Scaffolds

    Directory of Open Access Journals (Sweden)

    Chiaki Kitamura

    2012-01-01

    Full Text Available Restorative and endodontic procedures have been recently developed in an attempt to preserve the vitality of dental pulp after exposure to external stimuli, such as caries infection or traumatic injury. When damage to dental pulp is reversible, pulp wound healing can proceed, whereas irreversible damage induces pathological changes in dental pulp, eventually requiring its removal. Nonvital teeth lose their defensive abilities and become severely damaged, resulting in extraction. Development of regeneration therapy for the dentin-pulp complex is important to overcome limitations with presently available therapies. Three strategies to regenerate the dentin-pulp complex have been proposed; regeneration of the entire tooth, local regeneration of the dentin-pulp complex from amputated dental pulp, and regeneration of dental pulp from apical dental pulp or periapical tissues. In this paper, we focus on the local regeneration of the dentin-pulp complex by application of exogenous growth factors and scaffolds to amputated dental pulp.

  4. Human pulp response to acid pretreatment of dentin and to composite restoration.

    Science.gov (United States)

    Stanley, H R; Going, R E; Chauncey, H H

    1975-10-01

    The newer composites, although free of methacrylic acid and of a neutral pH, were still found to be toxic to the pulp. The intensity of response was increased after acid pretreatment procedures; this indicates an increase in dentin permeability. When the remaining dentin thickness was 1.0 mm or less, regardless of whether the dentin was primary dentin or primary and reparative dentin, the percentage of teeth with abscess formations increased. Use of calcium hydroxide bases or liners to coat the dentin before acid pretreatment of enamel is therefore highly recommended.

  5. Dental Pulp and Dentin Tissue Engineering and Regeneration – Advancement and Challenge

    Science.gov (United States)

    Huang, George T.-J.

    2012-01-01

    Hard tissue is difficult to repair especially dental structures. Tooth enamel is incapable of self-repairing whereas dentin and cememtum can regenerate with limited capacity. Enamel and dentin are commonly under the attack by caries. Extensive forms of caries destroy enamel and dentin and can lead to dental pulp infection. Entire pulp amputation followed by the pulp space disinfection and filled with an artificial rubber-like material is employed to treat the infection --commonly known as root canal or endodontic therapy. Regeneration of dentin relies on having vital pulps; however, regeneration of pulp tissue has been difficult as the tissue is encased in dentin without collateral blood supply except from the root apical end. With the advent of modern tissue engineering concept and the discovery of dental stem cells, regeneration of pulp and dentin has been tested. This article will review the recent endeavor on pulp and dentin tissue engineering and regeneration. The prospective outcome of the current advancement and challenge in this line of research will be discussed. PMID:21196351

  6. Conduction of reparative dentin: A pulp protecting approach by indirect pulp capping in deep carious lesion with biodentine

    Directory of Open Access Journals (Sweden)

    Rafeza Sultana

    2016-12-01

    Full Text Available This case report represents, the treatment of deep carious lesion in a male was done by using indirect pulp capping with biodentine. The clinical and radiological outcomes were evaluated. The patient was presented with mild to moderate sensitivity on thermal (cold stimulation and discomfort associated with eating in the left mandibular first molar. The clinico–radiographical examination revealed a disto–occlusal carious lesion, very close to the pulp, absence of radiolucencies in the periapical region and no periodontal space widening. Pulp sensitivity was confirmed by thermal pulp vitality test. Indirect pulp capping treatment was performed with biodentine. Following 6 months of the treatment, the clinical symptoms were resolved and a calcific bridge was found at the dentin over the pulp and biodentine interface that was indicative the evidence of reparative dentin formation.

  7. Topical application of lithium chloride on the pulp induces dentin regeneration.

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    Kazuya Ishimoto

    Full Text Available We herein describe a novel procedure for dentin regeneration that mimics the biological processes of tooth development in nature. The canonical Wnt signaling pathway is an important regulator of the Dentin sialophosphoprotein (Dspp expression. Our approach mimics the biological processes underlying tooth development in nature and focuses on the activation of canonical Wnt signaling to trigger the natural process of dentinogenesis. The coronal portion of the dentin and the underlying pulp was removed from the first molars. We applied lithium chloride (LiCl, an activator of canonical Wnt signaling, on the amputated pulp surface to achieve transdifferentiation toward odontoblasts from the surrounding pulpal cells. MicroCT and microscopic analyses demonstrated that the topical application of LiCl induced dentin repair, including the formation of a complete dentin bridge. LiCl-induced dentin is a tubular dentin in which the pulp cells are not embedded within the matrix, as in primary dentin. In contrast, a dentin bridge was not induced in the control group treated with pulp capping with material carriers alone, although osteodentin without tubular formation was induced at a comparatively deeper position from the pulp exposure site. We also evaluated the influence of LiCl on differentiation toward odontoblasts in vitro. In the mDP odontoblast cell line, LiCl activated the mRNA expression of Dspp, Axin2 and Kallikrein 4 (Klk4 and downregulated the Osteopontin (Osp expression. These results provide a scientific basis for the biomimetic regeneration of dentin using LiCl as a new capping material to activate dentine regeneration.

  8. Topical Application of Lithium Chloride on the Pulp Induces Dentin Regeneration

    Science.gov (United States)

    Ishimoto, Kazuya; Hayano, Satoru; Yanagita, Takeshi; Kurosaka, Hiroshi; Kawanabe, Noriaki; Itoh, Shinsuke; Ono, Mitsuaki; Kuboki, Takuo; Kamioka, Hiroshi; Yamashiro, Takashi

    2015-01-01

    We herein describe a novel procedure for dentin regeneration that mimics the biological processes of tooth development in nature. The canonical Wnt signaling pathway is an important regulator of the Dentin sialophosphoprotein (Dspp) expression. Our approach mimics the biological processes underlying tooth development in nature and focuses on the activation of canonical Wnt signaling to trigger the natural process of dentinogenesis. The coronal portion of the dentin and the underlying pulp was removed from the first molars. We applied lithium chloride (LiCl), an activator of canonical Wnt signaling, on the amputated pulp surface to achieve transdifferentiation toward odontoblasts from the surrounding pulpal cells. MicroCT and microscopic analyses demonstrated that the topical application of LiCl induced dentin repair, including the formation of a complete dentin bridge. LiCl-induced dentin is a tubular dentin in which the pulp cells are not embedded within the matrix, as in primary dentin. In contrast, a dentin bridge was not induced in the control group treated with pulp capping with material carriers alone, although osteodentin without tubular formation was induced at a comparatively deeper position from the pulp exposure site. We also evaluated the influence of LiCl on differentiation toward odontoblasts in vitro. In the mDP odontoblast cell line, LiCl activated the mRNA expression of Dspp, Axin2 and Kallikrein 4 (Klk4) and downregulated the Osteopontin (Osp) expression. These results provide a scientific basis for the biomimetic regeneration of dentin using LiCl as a new capping material to activate dentine regeneration. PMID:25812134

  9. A Model System for Predicting Drug Penetration thru Decayed Dentin into Inflamed Pulps

    Science.gov (United States)

    1991-01-09

    FOGEL, H.; MARSHALL, F.; and PASHLEY , D.; (1988): Effects of Distance from the Pulp and Thickness on the Hydraulic Conductance of Human Radicular Dentin ...559. PASHLEY , D.; THOMPSON, S.; and STEWART, F. (19 8 3 b): Dentin Permeability: Effects of Temperature on Hydraulic Conductance , J Dent Res 62(9...WALTON, R.; LIVINGSTON, M.; and PASHLEY , D. (1978): Dentin Permeability: Determinants of Hydraulic Conductance , J Dent Res 57(2): 187-193. ROBBINS, S

  10. Clinical and Histological Evaluation of Direct Pulp Capping on Human Pulp Tissue Using a Dentin Adhesive System

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    Alicja Nowicka

    2016-01-01

    Full Text Available Objective. This study presents a clinical and histological evaluation of human pulp tissue responses after direct capping using a new dentin adhesive system. Methods. Twenty-eight caries-free third molar teeth scheduled for extraction were evaluated. The pulps of 22 teeth were mechanically exposed and randomly assigned to 1 of 2 groups: Single Bond Universal or calcium hydroxide. Another group of 6 teeth acted as the intact control group. The periapical response was assayed, and a clinical examination was performed. The teeth were extracted after 6 weeks, and a histological analysis was performed. The pulp status was assessed, and the thickness of the dentin bridge was measured and categorized using a histological scoring system. Results. The clinical phase was asymptomatic for Single Bond Universal patients. Patients in the calcium hydroxide group reported mild symptoms of pain, although the histological examination revealed that dentin bridges with or without limited pulpitis had begun forming in each tooth. The universal adhesive system exhibited nonsignificantly increased histological signs of pulpitis (P>0.05 and a significantly weaker thin mineralized tissue layer (P<0.001 compared with the calcium hydroxide group. Conclusion. The results suggest that Single Bond Universal is inappropriate for human pulp capping; however, further long-term studies are needed to determine the biocompatibility of this agent.

  11. Clinical and Histological Evaluation of Direct Pulp Capping on Human Pulp Tissue Using a Dentin Adhesive System

    Science.gov (United States)

    Parafiniuk, Mirosław; Grocholewicz, Katarzyna; Sobolewska, Ewa; Buczkowska-Radlińska, Jadwiga

    2016-01-01

    Objective. This study presents a clinical and histological evaluation of human pulp tissue responses after direct capping using a new dentin adhesive system. Methods. Twenty-eight caries-free third molar teeth scheduled for extraction were evaluated. The pulps of 22 teeth were mechanically exposed and randomly assigned to 1 of 2 groups: Single Bond Universal or calcium hydroxide. Another group of 6 teeth acted as the intact control group. The periapical response was assayed, and a clinical examination was performed. The teeth were extracted after 6 weeks, and a histological analysis was performed. The pulp status was assessed, and the thickness of the dentin bridge was measured and categorized using a histological scoring system. Results. The clinical phase was asymptomatic for Single Bond Universal patients. Patients in the calcium hydroxide group reported mild symptoms of pain, although the histological examination revealed that dentin bridges with or without limited pulpitis had begun forming in each tooth. The universal adhesive system exhibited nonsignificantly increased histological signs of pulpitis (P > 0.05) and a significantly weaker thin mineralized tissue layer (P < 0.001) compared with the calcium hydroxide group. Conclusion. The results suggest that Single Bond Universal is inappropriate for human pulp capping; however, further long-term studies are needed to determine the biocompatibility of this agent. PMID:27803922

  12. A COMPARATIVE EVALUATION OF EFFECT OF SODIUM HYPOCHLORITE ON MICROTENSILE BOND STRENGTH OF THREE DIFFERENT BONDING AGENTS TO THE LATERAL WALLS OF PULP CHAMBER: AN IN VITRO STUDY

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    Bhat Gowrish S.

    2013-03-01

    Full Text Available The advent of adhesive materials has revolutionized the field of restorative dentistry. Lack of adhesion and sealing between the final restoration and tooth structure may lead to microleakage and ultimate failure of the restoration. These adhesive restorations are also being used in the field of endodontics. A good coronal seal is very important, since the penetration of microorganisms from a coronal direction can reinfect the root canal system and affect the prognosis of the non-surgical root canal therapy. Coronal leakage is particularly significant in multi rooted teeth, in which accessory canal may allow inflammatory change to occur in the periodontal tissues from the pulp chambers. Improper restoration can lead to loss of endodontically treated teeth more than actual failure of endodontic therapy. The restorations with adhesive systems offer the advantage of transmission of functional stresses across the bonded interface to the tooth (mono bloc restoration and potentially reinforce the weakened tooth structure. Bonding to pulp chamber lateral walls is different from bonding other dentinal surface. The structure of pulp chamber wall is complicated and not much is known about the bonding characteristics of pulp chamber, it becomes essential to study the same. This study was done evaluate the effect of sodium hypochlorite on bond strength of bonding agent to the lateral walls of the pulp chamber. However, chemical irrigants, such as sodium hypochlorite used in the endodontic treatment have been shown to affect the bond strength of resin composite to dentin adversely.

  13. Root maturation and dentin-pulp response to enamel matrix derivative in pulpotomized permanent teeth.

    Science.gov (United States)

    Darwish, Sherif S; Abd El Meguid, Shadia H; Wahba, Nadia A; Mohamed, Ahmed A-R; Chrzanowski, Wojciech; Abou Neel, Ensanya A

    2014-01-01

    The success of pulpotomy of young permanent teeth depends on the proper selection of dressing materials. This study aimed to evaluate the histological and histomorphometric response of dentin-pulp complex to the enamel matrix derivative (Emdogain(®) gel) compared to that of calcium hydroxide when used as a pulp dressing in immature young permanent dogs' teeth. Dentin-like tissues bridging the full width of the coronal pulp at the interface between the injured and healthy pulp tissues were seen after 1 month in both groups. With time, the dentin bridge increased in thickness for calcium hydroxide but disintegrated and fully disappeared for Emdogain-treated group. Progressive inflammation and total pulp degeneration were only evident with Emdogain-treated group. The root apices of Emdogain-treated teeth became matured and closed by cementum that attached to new alveolar bone by a well-oriented periodontal ligament. In young permanent dentition, Emdogain could be a good candidate for periodontium but not dentino-pulpal complex regeneration.

  14. Detection of organochlorine compounds formed during the contact of sodium hypochlorite with dentin and dental pulp.

    Science.gov (United States)

    Varise, Tiago Gilioli; Estrela, Carlos; Guedes, Débora Fernandes Costa; Sousa-Neto, Manoel Damião; Pécora, Jesus Djalma

    2014-01-01

    This study used gas chromatography-mass spectrometry (GC-MS) to detect the products formed during the contact of sodium hypochlorite (NaOCl) with bovine pulp and dentin. For analysis of the products formed in the volatile phase, 11 mg of bovine pulp tissue were placed in contact with 0.5%, 2.5% and 5.25% NaOCl until complete tissue dissolution occurred. The solid phase microextraction (SPME) fiber was exposed inside the container through the cover membrane and immediately injected into the GC-MS system. 30 mg of the of dentin were kept in contact with NaOCl, and then the SPME fiber was exposed inside the container through the cover membrane for adsorption of the products and injected into the GC-MS system. The same protocol was used for the aqueous phase. For analysis of the volatile compounds, the final solution was extracted using pure ethyl ether. The suspended particulate phase of the mixture was aspirated, and ether was separated from the aqueous phase of the solution. The ether containing the products that resulted from the chemical interaction of dentin and pulp with the NaOCl was filtered and then injected into the GC-MS system for analysis of the aqueous phase. The aqueous and volatile phases of both dentin and pulp showed the formation of chloroform, hexachloroethane, dichloromethylbenzene and benzaldehyde. In conclusion, organochlorine compounds are generated during the contact of dentin and pulp with NaOCl at concentrations of 0.5%, 2.5% and 5.25%.

  15. Potential Role of Dentin Sialoprotein by Inducing Dental Pulp Mesenchymal Stem Cell Differentiation and Mineralization for Dental Tissue Repair

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    Zhi Chen

    2010-09-01

    Full Text Available Introduction: Dentin sialoprotein (DSP is a dentin extracellular matrix protein, a unique marker of dentinogenesis and plays a vital role in odontoblast differentiation and dentin mineralization. Recently, studies have shown that DSP induces differentiation and mineralization of periodontal ligament stem cells and dental papilla mesenchymal cells in vitro and rescues dentin deficiency and increases enamel mineralization in animal models.The hypothesis: DSP as a nature therapeutic agent stimulates dental tissue repair by inducing endogenous dental pulp mesenchymal stem/progenitor cells into odontoblast-like cells to synthesize and to secrete dentin extracellular matrix forming new tertiary dentin as well as to regenerate a functional dentin-pulp complex. As DSP is a nature protein, and clinical procedure for DSP therapy is easy and simple, application of DSP may provide a new avenue for dentists with additional option for the treatment of substantially damaged vital teeth.Evaluation of the hypothesis: Dental caries is the most common dental disease. Deep caries and pulp exposure have been treated by various restorative materials with limited success. One promising approach is dental pulp stem/progenitor-based therapies to regenerate dentin-pulp complex and restore its functions by DSP induction in vivo.

  16. The application of tissue engineering to regeneration of pulp and dentin in endodontics.

    Science.gov (United States)

    Nakashima, Misako; Akamine, Akifumi

    2005-10-01

    Caries, pulpitis, and apical periodontitis increase health care costs and attendant loss of economic productivity. They ultimately result in premature tooth loss and therefore diminishing the quality of life. Advances in vital pulp therapy with pulp stem/progenitor cells might give impetus to regenerate dentin-pulp complex without the removal of the whole pulp. Tissue engineering is the science of design and manufacture of new tissues to replace lost parts because of diseases including cancer and trauma. The three key ingredients for tissue engineering are signals for morphogenesis, stem cells for responding to morphogens and the scaffold of extracellular matrix. In preclinical studies cell therapy and gene therapy have been developed for many tissues and organs such as bone, heart, liver, and kidney as a means of delivering growth factors, cytokines, or morphogens with stem/progenitor cells in a scaffold to the sites of tissue injury to accelerate and/or induce a natural biological regeneration. The pulp tissue contains stem/progenitor cells that potentially differentiate into odontoblasts in response to bone morphogenetic proteins (BMPs). There are two strategies to regenerate dentin. First, is in vivo therapy, where BMP proteins or BMP genes are directly applied to the exposed or amputated pulp. Second is ex vivo therapy and consists of isolation of stem/progenitor cells from pulp tissue, differentiation into odontoblasts with recombinant BMPs or BMP genes and finally transplanted autogenously to regenerate dentin. This review is focused on the recent progress in this area and discusses the barriers and challenges for clinical utility in endodontics.

  17. The distinct distributions of immunocompetent cells in rat dentin pulp after pulpotomy.

    Science.gov (United States)

    Zhang, Min; Kokabu, Shoichiro; Nakatomi, Chihiro; Sugiyama, Goro; Matsuo, Kou; Jimi, Eijiro

    2015-04-01

    Pulpotomy involves the removal of the coronal portion of pulp, including the diseased tissue, with the intent of maintaining the vitality of the remaining pulpal tissue via a therapeutic dressing. Once odontoblasts suffer injuries, the differentiation of mesenchymal cells is induced from the precursor cell population in the dental pulp, and these cells are recruited to the injured site to differentiate into odontoblasts. However, the involvement of immunocompetent cells during pulpal regeneration remains unclear. Thus, the purpose of this study was to investigate the properties of macrophages that infiltrated wound healing sites in rats between 1 and 28 days after pulpotomy (dap). During the inflammatory phase, ED1(+) (CD68(+) ) macrophages significantly increased throughout root pulp, especially apical to the demarcation zone, and this population persisted until 3 dap before decreasing gradually until 28 dap. OX6(+) macrophages expressing class II MHC also increased in the apical pulp at 1 dap and declined thereafter. However, OX6(+) cells appeared prior to dentin bridge formation at 3 dap and appeared again apical to the dentin bridge during the healing stage at 14 dap. The shift from ED1(+) cells in the inflammation phase to OX6(+) cells during dentin bridge formation might contribute to wound healing.

  18. Tomographic Evaluation of Reparative Dentin Formation after Direct Pulp Capping with Ca(OH)2, MTA, Biodentine, and Dentin Bonding System in Human Teeth.

    Science.gov (United States)

    Nowicka, Alicja; Wilk, Grażyna; Lipski, Mariusz; Kołecki, Janusz; Buczkowska-Radlińska, Jadwiga

    2015-08-01

    New materials can increase the efficiency of pulp capping through the formation of a complete reparative dentin bridge with no toxic effects. The present study involved tomographic evaluations of reparative dentin bridge formation after direct pulp capping with calcium hydroxide, mineral trioxide aggregate (MTA), Biodentine (Septodont, Saint Maur des Fossés, France), and Single Bond Universal (3M ESPE, Seefeld, Germany) in human teeth. Forty-four caries-free, intact, human third molars scheduled for extraction were subjected to mechanical pulp exposure and assigned to 1 of 4 experimental groups depending on the pulp capping agent used: calcium hydroxide, MTA, Biodentine, or Single Bond Universal. After 6 weeks, the teeth were extracted and processed for cone-beam computed tomographic imaging and histologic examination. Tomographic data, including the density and volume of formed reparative dentin bridges, were evaluated using a scoring system. The reparative dentin formed in the calcium hydroxide, MTA, and Biodentine groups was significantly superior to that formed in the Single Bond Universal group in terms of thickness and volume. The dentin bridges in the Biodentine group showed the highest average and maximum volumes. The mean density of dentin bridges was the highest in the MTA group and the lowest in the Single Bond Universal group. The volume of reparative dentin bridges formed after direct pulp capping is dependent on the material used. Biodentine and MTA resulted in the formation of bridges with a significantly higher average volume compared with Single Bond Universal, and cone-beam computed tomographic imaging allowed for the identification of the location of dentin bridges. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Acemannan, an extracted product from Aloe vera, stimulates dental pulp cell proliferation, differentiation, mineralization, and dentin formation.

    Science.gov (United States)

    Jittapiromsak, Nawaporn; Sahawat, Dusida; Banlunara, Wijit; Sangvanich, Polkit; Thunyakitpisal, Pasutha

    2010-06-01

    This study investigated the effect of acemannan (Aloe vera gel polysaccharide) on dentin formation. Primary human dental pulp cells were treated with acemannan. New DNA synthesis, bone morphogenetic protein-2, alkaline phosphatase activity, dentin sialoprotein expression, and mineralization were determined by [(3)H]-thymidine incorporation, enzyme-linked immunosorbent assay, biochemical assay, western blotting, and Alizarin Red staining, respectively. Then the upper first molars of 24 male Sprague Dawley rats were intentionally exposed and capped with either acemannan or calcium hydroxide. At day 28, the teeth were histopathologically examined and evaluated for the degree of inflammation, dentin bridge formation, and pulp tissue organization. The results revealed that acemannan significantly increased pulp cell proliferation, bone morphogenetic protein-2, alkaline phosphatase activity, dentin sialoprotein expression, and mineralization, compared with the untreated group. The acemannan-treated group also exhibited a complete homogeneous calcified dentin bridge and good pulp tissue organization, whereas neither was detected in the calcium hydroxide-treated and sham groups. In the acemannan-treated group, either mild or no inflammation was found, whereas the other groups had various degrees of inflammation. The data suggest that acemannan promotes dentin formation by stimulating primary human dental pulp cell proliferation, differentiation, extracellular matrix formation, and mineralization. Acemannan also has pulpal biocompatibility and promotes soft tissue organization.

  20. Pulp-dentin biology in restorative dentistry. Part 4: Dental caries--characteristics of lesions and pulpal reactions.

    Science.gov (United States)

    Bjørndal, L; Mjör, I A

    2001-10-01

    The infectious disease dental caries results in lesions that may affect enamel, dentin, pulp, and cementum. If a caries lesion has progressed to the stage at which it requires restorative intervention, it is important that the clinician understand the tissue changes in the dentin that are likely to have taken place during lesion development. Until the present, no major distinction between the restorative treatment of active (rapidly progressing) and arrested (slowly progressing) lesions has been made, despite the fact that the two conditions exhibit major differences in tissue changes in the pulp-dentin complex. Intratubular changes and tertiary dentin formation will affect the outcome of the restorative treatment. In unaffected dentin and in rapidly progressing lesions, permeable tubules persist, and when the preparation of carious teeth results in the opening of unaffected dentin, greater care must be taken in all phases of the restorative procedures than if the dentin is impermeable. An active, deep lesion can be changed to an arrested lesion by a two-step excavation approach. Optimal assessment of the prevailing clinical conditions can only be made on the basis of thorough knowledge of the biology of the pulp-dentin organ.

  1. Dentin-pulp complex regeneration: from lab to clinic.

    Science.gov (United States)

    Simon, S R J; Berdal, A; Cooper, P R; Lumley, P J; Tomson, P L; Smith, A J

    2011-07-01

    Dentistry is entering an exciting era in which many of the advances in biotechnology offer opportunities for exploitation in novel and more effective therapies. Pulp healing is complex and dependent on the extent of injury, among many other factors. Many of the molecular and cellular processes involved in these healing events recapitulate developmental processes. The regulation of odontoblast activity is clearly central to pulp healing, and an understanding of the mechanisms involved in these processes is necessary to enable laboratory studies to be translated to clinic application. Transcriptome analysis has identified changes in many odontoblast genes during the life-cycle of this cell and its responses to injurious challenge. The p38 MAPKinase pathway appears to be central to the transcriptional control of odontoblasts and may provide a key target for therapeutic intervention. The many recent advances in knowledge of pulpal stem cells and molecular signaling molecules within the tooth, now provide exciting opportunities for clinical translation to novel therapies. Such translation will require the partnership of researchers and skilled clinicians who can effectively apply advances in knowledge to appropriate clinical cases and develop novel therapies which can be realistically introduced into the clinic.

  2. Current Advance and Future Prospects of Tissue Engineering Approach to Dentin/Pulp Regenerative Therapy

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    Ting Gong

    2016-01-01

    Full Text Available Recent advances in biomaterial science and tissue engineering technology have greatly spurred the development of regenerative endodontics. This has led to a paradigm shift in endodontic treatment from simply filling the root canal systems with biologically inert materials to restoring the infected dental pulp with functional replacement tissues. Currently, cell transplantation has gained increasing attention as a scientifically valid method for dentin-pulp complex regeneration. This multidisciplinary approach which involves the interplay of three key elements of tissue engineering—stem cells, scaffolds, and signaling molecules—has produced an impressive number of favorable outcomes in preclinical animal studies. Nevertheless, many practical hurdles need to be overcome prior to its application in clinical settings. Apart from the potential health risks of immunological rejection and pathogenic transmission, the lack of a well-established banking system for the isolation and storage of dental-derived stem cells is the most pressing issue that awaits resolution and the properties of supportive scaffold materials vary across different studies and remain inconsistent. This review critically examines the classic triad of tissue engineering utilized in current regenerative endodontics and summarizes the possible techniques developed for dentin/pulp regeneration.

  3. Current Advance and Future Prospects of Tissue Engineering Approach to Dentin/Pulp Regenerative Therapy.

    Science.gov (United States)

    Gong, Ting; Heng, Boon Chin; Lo, Edward Chin Man; Zhang, Chengfei

    2016-01-01

    Recent advances in biomaterial science and tissue engineering technology have greatly spurred the development of regenerative endodontics. This has led to a paradigm shift in endodontic treatment from simply filling the root canal systems with biologically inert materials to restoring the infected dental pulp with functional replacement tissues. Currently, cell transplantation has gained increasing attention as a scientifically valid method for dentin-pulp complex regeneration. This multidisciplinary approach which involves the interplay of three key elements of tissue engineering-stem cells, scaffolds, and signaling molecules-has produced an impressive number of favorable outcomes in preclinical animal studies. Nevertheless, many practical hurdles need to be overcome prior to its application in clinical settings. Apart from the potential health risks of immunological rejection and pathogenic transmission, the lack of a well-established banking system for the isolation and storage of dental-derived stem cells is the most pressing issue that awaits resolution and the properties of supportive scaffold materials vary across different studies and remain inconsistent. This review critically examines the classic triad of tissue engineering utilized in current regenerative endodontics and summarizes the possible techniques developed for dentin/pulp regeneration.

  4. Current Advance and Future Prospects of Tissue Engineering Approach to Dentin/Pulp Regenerative Therapy

    Science.gov (United States)

    Gong, Ting; Heng, Boon Chin; Lo, Edward Chin Man; Zhang, Chengfei

    2016-01-01

    Recent advances in biomaterial science and tissue engineering technology have greatly spurred the development of regenerative endodontics. This has led to a paradigm shift in endodontic treatment from simply filling the root canal systems with biologically inert materials to restoring the infected dental pulp with functional replacement tissues. Currently, cell transplantation has gained increasing attention as a scientifically valid method for dentin-pulp complex regeneration. This multidisciplinary approach which involves the interplay of three key elements of tissue engineering—stem cells, scaffolds, and signaling molecules—has produced an impressive number of favorable outcomes in preclinical animal studies. Nevertheless, many practical hurdles need to be overcome prior to its application in clinical settings. Apart from the potential health risks of immunological rejection and pathogenic transmission, the lack of a well-established banking system for the isolation and storage of dental-derived stem cells is the most pressing issue that awaits resolution and the properties of supportive scaffold materials vary across different studies and remain inconsistent. This review critically examines the classic triad of tissue engineering utilized in current regenerative endodontics and summarizes the possible techniques developed for dentin/pulp regeneration. PMID:27069484

  5. Clinical and histological responses of human dental pulp to MTA and combined MTA/treated dentin matrix in partial pulpotomy.

    Science.gov (United States)

    Mehrvarzfar, Payman; Abbott, Paul V; Mashhadiabbas, Fatemeh; Vatanpour, Mehdi; Tour Savadkouhi, Sohrab

    2017-08-18

    The aim of this study was to compare the responses of mineral trioxide aggregate (MTA) and combined MTA/treated dentin matrix (TDM) as direct pulp capping material. In this clinical trial study, 33 intact third molars in 11 healthy volunteers (three molars in each) were included. Partial pulpotomies were performed in a split mouth manner in two of the third molars in each patient randomly and the third tooth had used as TDM source. The coronal dentin was chopped to dentine chips and transformed to TDM using different concentrations of ethylene diamine tetraacetic acid (EDTA) solution. Pulps were directly capped by MTA alone or using a combination layering of MTA/TDM. Following 6-week clinical and radiological evaluations, each tooth was extracted and prepared for histological evaluation. There were no significant differences in the clinical and radiographic responses or in the quality of dentin bridges (P > 0.05). However, the dentin bridge was significantly thicker in MTA/TDM group than MTA group (P = 0.003). Using the combination of MTA/TDM as a pulp-dressing agent may form a thicker dentin bridge compared to MTA alone. © 2017 Australian Society of Endodontology Inc.

  6. CLINICAL, HISTOLOGICAL AND RADIOLOGICAL ASPECTS REGARDING THE INFLUENCE OF SOME EXTERNAL FACTORS ON THE PULP-DENTIN COMPLEX

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    C. Giuroiu

    2012-12-01

    Full Text Available The present study aimed at assesssing – by clinical, histological and radiological investigations – the influence of some external factors on the pulp-dentin complex, and at providing a causal interpretation of the structural changes observed. Materials and methods. Clinical and radiological exams were performed on 65 old patients with ages between 60-75, and also on 40 young patients with ages between 20-35, presenting different dental-periodontal pathologies. The pulp-dentin complex was submitted to a morphopathological examination, to highlight the structural changes observed at microscopic level. Fragments of dental pulp were imersed in a 4% formaldehyde solution with phosphate buffer 0.1 M., pH 7.2, for 12 -14 hours, at a temperature of 4ºC, and 3-5 µm thick slices were prepared. The slices were coloured with hematoxylin-eosine (HE, by the trichromic technique – Masson. Photographies were taken with a Zeiss microscope, with Kodak 200 ASA. Results. Significant differences were observed, between the two groups of patients, as to the external factors that produce structural changes on pulp-dentin organ. In the group of young patients dental caries and coronal fillings prevailed, while the group of old patients was mostly associated with atrition and chronic marginal periodontitis. Out of the 40 young patients, 30 presented chronic dental caries (75%, while, among the 65 old patients, only 24 presented dental caries (36.9%. The percentages of coronary fillings between the two study groups were close, which could be considered as one of the causes producing changes in the pulp-dentin organ, following aggresive preparation of cavities, the action of materials used for the protection of pulp-dentin complex or of the materials used for coronry fillings. Conclusions. Dental pulp has a remarkable ability to counteract the action of harmful factors, producing a mineral barrier and stimulating the reparatory processes. Changes in the endodontic

  7. Autologous Platelet Concentrates for Pulp and Dentin Regeneration: A Literature Review of Animal Studies.

    Science.gov (United States)

    Del Fabbro, Massimo; Lolato, Alessandra; Bucchi, Cristina; Taschieri, Silvio; Weinstein, Roberto L

    2016-02-01

    The purpose of this study was to evaluate the effectiveness of autologous platelet concentrates (APCs) in promoting pulp and dentin regeneration in animal models. An electronic search was performed on MEDLINE, Embase, Scopus, SciELO, LILACS, and CENTRAL. Animal studies using APC as a root filling material after pulpectomy in mature or immature teeth were included. Articles underwent risk of bias assessment. Histologic evaluation of intracanal neoformed tissue was the primary outcome; root development, root wall thickening, apical closure, and periapical healing in apical periodontitis were the secondary outcomes. Seven articles were included. Platelet-rich plasma (PRP) was used as root filling material during regenerative procedures in the experimental group in either mature or immature teeth. After revascularization with PRP alone or in conjunction with stem cells of a different source, the histologic analyses revealed that, in addition to an odontoblastic cell layer or dentinlike structure, the neoformed intracanal tissues were mainly cementumlike, bonelike, and connective tissues. True regeneration of necrotic pulp may not be achieved with current techniques using PRP, all of which stimulated tissue repair. Benefits of PRP adjunct for pulp tissue regeneration in preclinical studies remain unclear. Further studies with standardized protocols are necessary to assess the actual contribution of PRP in endodontic regenerative therapies. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Immunolocalization of dentin matrix protein-1 in human primary teeth treated with different pulp capping materials.

    Science.gov (United States)

    Lourenço Neto, Natalino; Marques, Nádia C T; Fernandes, Ana Paula; Rodini, Camila O; Sakai, Vivien T; Abdo, Ruy Cesar C; Machado, Maria Aparecida A M; Santos, Carlos F; Oliveira, Thais M

    2016-01-01

    The aim of this study was to evaluate the immunolocalization of dentin matrix protein (DMP)-1 in human primary teeth treated with different pulp capping materials. Twenty-five primary molars were divided into the following groups: formocresol (FC), calcium hydroxide (CH), mineral trioxide aggregate (MTA), corticosteroid/antibiotic solution + CH (O + CH), and Portland cement (PC), and all received conventional pulpotomy treatment. The teeth at the regular exfoliation period were extracted for histological analysis and immunolocalization of DMP-1. Statistical analysis was performed using the χ(2) test (p < 0.05). Histological analysis revealed statistically significant differences in the comparison among the groups through the use of a score system regarding the presence of hard tissue barrier, odontoblastic layer, and internal resorption, but not regarding pulp calcification. Immunohistochemical analysis showed immunostaining for DMP-1 in groups CH, MTA, O + CH, and PC. Internal resorption was observed in the groups FC and CH. MTA and PC showed pulp repair without inflammation and with the presence of hard tissue barrier. DMP-1 immunostaining was higher for MTA and PC, confirming the reparative and bioinductive capacity of these materials.

  9. Exploiting the Bioactive Properties of the Dentin-Pulp Complex in Regenerative Endodontics.

    Science.gov (United States)

    Smith, Anthony J; Duncan, Henry F; Diogenes, Anibal; Simon, Stephane; Cooper, Paul R

    2016-01-01

    The development of regenerative endodontic therapies offers exciting opportunities for future improvements in treatment outcomes. Advances in our understanding of regenerative events at the molecular and cellular levels are helping to underpin development of these therapies, although the various strategies differ in the translational challenges they pose. The identification of a variety of bioactive molecules, including growth factors, cytokines, chemokines, and matrix molecules, sequestered within dentin and dental pulp provides the opportunity to present key signaling molecules promoting reparative and regenerative events after injury. The protection of the biological activity of these molecules by mineral in dentin before their release allows a continuing supply of these molecules, while avoiding the short half-life and the non-human origin of exogenous molecules. The ready release of these bioactive molecules by the various tissue preparation agents, medicaments, and materials commonly used in endodontics highlights the opportunities for translational regenerative strategies exploiting these molecules with little change to existing clinical practice. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  10. 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.

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

    Science.gov (United States)

    Lymperi, Stefania; Taraslia, Vasiliki; Tsatsoulis, Ioannis N.; Samara, Athina; Agrafioti, Anastasia; Anastasiadou, Ema; Kontakiotis, Evangelos

    2015-01-01

    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. PMID:26146613

  12. Regeneration of the dentine-pulp complex with revitalization/revascularization therapy: challenges and hopes.

    Science.gov (United States)

    Lin, L M; Ricucci, D; Huang, G T-J

    2014-08-01

    The concept of regenerative endodontics has gained much attention in clinical endodontics in the past decade. One aspect of this discipline is the application of revitalization/revascularization therapies for infected and/or necrotic immature pulps in permanent teeth. Following the publication of a case report (Iwaya et al. ), investigators have been rigorously examining the types of tissues formed in the canals as well as exploring strategies to regenerate the pulp-dentine complex in revitalized teeth. This review will provide an update on the types of tissues generated in the canals after revitalization/revascularization therapy in both animal and human studies. The understanding of the role of stem cells and microenvironment in the process of wound healing resulting in either regeneration or repair will be thoroughly discussed. Stem cells and microenvironmental cues introduced into the canal during revitalization/revascularization procedures will be examined. In addition, requirement of a sterile microenvironment in the canal and vital tissue generation in revitalization/revascularization therapy will be emphasized. The challenges that we face and the hopes that we have in revitalization/revascularization therapy for regenerative endodontics will be presented. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  13. Pulp-dentine complex changes and root resorption during intrusive orthodontic tooth movement in patients prescribed nabumetone.

    Science.gov (United States)

    Villa, Paula A; Oberti, Giovanni; Moncada, Cesar A; Vasseur, Olga; Jaramillo, Alejandro; Tobón, Diego; Agudelo, Jaime A

    2005-01-01

    Pulpitis, external root resorption, and pain may be experienced during orthodontic movement. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) has been suggested to control these changes. The purpose of this study was to observe pulp-dentinal reactions, root resorption, tooth pain, and tooth movement after the application of a 4-ounce intrusive orthodontic force to human maxillary first premolars in patients given the NSAID nabumetone. Thirty-four maxillary first premolars were evaluated. A placebo was prescribed to 17 patients after an intrusive force was activated and reactivated for an 8-week period on the right side. The same procedure was repeated on the left side after patients were given nabumetone. Pulp-dentinal reactions and external root resorption were evaluated by histology. Pain and movement were also evaluated. Nabumetone was found to be useful in reducing pulpitis, external root resorption, and pain caused by intrusive orthodontic movement, without altering tooth movement in response to the application of orthodontic force.

  14. Effect of betamethasone on the pulp after topical application to the dentin of rat teeth: vascular aspects of the inflammation

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    Elaine Vianna Freitas Fachin

    2009-08-01

    Full Text Available OBJECTIVE: This study investigated the pulpal effect of topically applied betamethasone to the dentin of rat molars in the vascular phase of inflammation. MATERIAL AND METHODS: Deep cavities were prepared on the occlusal face of the maxillary right and left 1st molars with non-refrigerated inverted-cone steel burs at low speed. Three groups were formed: Group I was composed of right 1st molars; Group II was composed of left 1st molars that received the application of a drop of betamethasone on dentin surface for 5 min; and Group III (control was composed of right 2nd molars that received no cavity preparation or betamethasone application. Changes in the vascular characteristics of the pulp tissue were checked by calculating the pulp vascular area in relation to its total area and the number of blood vessels per unit area. Data were subjected to ANOVA and Tukey's test (?=0.05. RESULTS: Group I presented a significantly larger number of vessels (p<0.05 than Group II. Regarding the vascular/total area ratio (%, Group I presented statistically significantly higher values (p=0.01 than Groups II and III. CONCLUSION: Betamethasone applied on the dentin of rat teeth proved to reduce the vascular phase of pulp inflammation regarding vessel diameter and number of blood vessels.

  15. All- Ceramic Crown Preparation and the Remained wall Thickness of the Pulp Chamber

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    Mohammadzadeh Akhlaghi N.

    2012-12-01

    Full Text Available tatement of Problem: A minimally invasive method of preparation is essential to prevent tooth structure weakening and pulp irritation; especially for mandibular anterior single-tooth all-ceramic crowns. According to many investigations, one of the most important reasons of pulp injury caused by tooth preparation for different restorative procedures is reduced “remained wall thickness” (RWT. In order to protect the pulp from irritation, it is necessary to maintain a 0.5 mm of RWT.Purpose: The purpose of the present study was to evaluate the effect of all-ceramic crown preparation on pulp chamber RWT of mandibular incisors.Materials and Method: Mesiodistal and buccolingual initial images of 24 ex-tracted mandibular incisors were provided. The pulp chamber initial wall thick-nesses of buccal, lingual and proximal surfaces of cervical, 1and 2 mm above the cervical areas and also the incisal surfaces of incisal sections were measured using digital radiography and Photoshop software. After all-ceramic crown preparation, images were provided at the same initial positions. The initial and remained pulp chamber wall thicknesses were statistically evaluated and analyzed by ANOVA, paired t-test and a post hoc Tukey test.Results: Repeated measures ANOVA showed that the mean of pre- or post-preparation wall thicknesses were not significantly different for each surface at the three horizontal levels (p> 0.05. However, there were significant differences between the surfaces for each section. Comparison of pre- and post-preparation wall thicknesses revealed significant differences (p< 0.05. Proximal surfaces of cervical sections had the least RWT (0.42±0.12.Conclusion: According to the results of the present study, the least amount of initial and remained wall thicknesses of pulp chamber were related to the proximal surfaces, particularly in cervical areas. Therefore a reduction of preparation to 0.7 mm is suggested to prevent future pulp injury for

  16. Influence of whitening gel on pulp chamber temperature rise by in-office bleaching technique

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    Sandro Cordeiro Loretto

    Full Text Available INTRODUCTION: Dental bleaching is a conservative method for the aesthetic restoration of stained teeth. However, whitening treatments are likely to cause adverse effects when not well planned and executed. OBJECTIVE: This study evaluated the influence of whitening gel on temperature rise in the pulp chamber, using the in-office photoactivated dental bleaching technique. MATERIAL AND METHOD: The root portion of an upper central human incisor was sectioned 3mm below the cemento-enamel junction. The root canal was enlarged to permit the insertion of the K-type thermocouple sensor (MT-401 into the pulp chamber, which was filled with thermal paste to facilitate the transfer of heat during bleaching. Three photosensitive whitening agents (35% hydrogen peroxide were used: Whiteness HP (FGM, Whiteness HP Maxx (FGM and Lase Peroxide Sensy (DMC. An LED photocuring light (Flash Lite - Discus Dental was used to activate the whitening gels. Six bleaching cycles were performed on each group tested. The results were submitted to one-way ANOVA and LSD t-test (α<0.05. RESULT: The lowest mean temperature variation (ºC was detected for Lase Peroxide Sensy (0.20, while the highest was recorded for Whiteness HP (1.50. CONCLUSION: The Whiteness HP and Whiteness HP Maxx whitening gels significantly affected the temperature rise in the pulp chamber during bleaching, and this variation was dependent on the type of whitening gel used.

  17. Cytotoxicity evaluation of dentin contacting materials with dentin barrier test device using erbium-doped yttrium, aluminum, and garnet laser-treated dentin.

    Science.gov (United States)

    Ülker, H E; Ülker, M; Botsalı, M S; Dündar, A; Acar, H

    2014-09-01

    The effect of dentin contacting materials on three-dimensional cultures of pulp-derived cells was evaluated in a dentin barrier test device using erbium-doped yttrium, aluminum, and garnet (Er:YAG) laser-treated dentin. The test materials (iBond(®), G-Bond™, and Vitrebond™) were applied on laser-treated or untreated dentin discs. After 24 h of exposure with perfusion of the test chamber, cell survival was evaluated by enzyme activity and related to a nontoxic control material. The mean values of control tissues were set to represent 100% viability. Data were analyzed using Kruskal-Wallis and Mann-Whitney U test. Vitrebond was the most toxic material for both laser-treated and untreated dentin. On untreated dentin, G-bond was cytotoxic to the pulp-derived cells (p 0.05). However, G-Bond and iBond were not cytotoxic when they were applied to Er:YAG laser-treated dentin (p > 0.05). Er:YAG laser treatment of dentin may protect the pulp cells from toxic substances of dentin contacting restorative materials; however, this effect is material related. Taking into consideration the limitations of this in vitro study, the Er:YAG laser treatment of dentin before restoration might be an option for decreasing the cytotoxic effects of the dental materials. Further research is required for clinical applications. © The Author(s) 2014.

  18. Trophic Effects and Regenerative Potential of Mobilized Mesenchymal Stem Cells From Bone Marrow and Adipose Tissue as Alternative Cell Sources for Pulp/Dentin Regeneration.

    Science.gov (United States)

    Murakami, Masashi; Hayashi, Yuki; Iohara, Koichiro; Osako, Yohei; Hirose, Yujiro; Nakashima, Misako

    2015-01-01

    Dental pulp stem cell (DPSC) subsets mobilized by granulocyte-colony-stimulating factor (G-CSF) are safe and efficacious for complete pulp regeneration. The supply of autologous pulp tissue, however, is very limited in the aged. Therefore, alternative sources of mesenchymal stem/progenitor cells (MSCs) are needed for the cell therapy. In this study, DPSCs, bone marrow (BM), and adipose tissue (AD)-derived stem cells of the same individual dog were isolated using G-CSF-induced mobilization (MDPSCs, MBMSCs, and MADSCs). The positive rates of CXCR4 and G-CSFR in MDPSCs were similar to MADSCs and were significantly higher than those in MBMSCs. Trophic effects of MDPSCs on angiogenesis, neurite extension, migration, and antiapoptosis were higher than those of MBMSCs and MADSCs. Pulp-like loose connective tissues were regenerated in all three MSC transplantations. Significantly higher volume of regenerated pulp and higher density of vascularization and innervation were observed in response to MDPSCs compared to MBMSC and MADSC transplantation. Collagenous matrix containing dentin sialophosphoprotein (DSPP)-positive odontoblast-like cells was the highest in MBMSCs and significantly higher in MADSCs compared to MDPSCs. MBMSCs and MADSCs, therefore, have potential for pulp regeneration, although the volume of regenerated pulp tissue, angiogenesis, and reinnervation, were less. Thus, in conclusion, an alternative cell source for dental pulp/dentin regeneration are stem cells from BM and AD tissue.

  19. Clinical e radiographic sucess of indirect pulp capping with partial excavation of demineralization dentin in primary posterior teeth

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    Roberta Francisca Martins de Castro

    2009-10-01

    Full Text Available Objective: To assess the outcome of the indirect pulp capping technique after incomplete excavation of the demineralized dentin in primary molars of patients treated in the period from 2004 to 2006.Methods: Sample consisted of 81 teeth of 36 patients aged from 1-to-8 year-old. Clinical and radiographic inclusion criteria, as well as criteria of the success of the evaluated treatments were established.Results: There were four (4.9% failures and 77 (95.1% successful treatments. Treatment failure occurred in three girls and in one boy, and no statistically significant difference (p=0.341 was found. Twenty three teeth were treated with resin-modified glass-ionomer cement and 58 with composite resin, of which 22 and 55, respectively, showed successful results. There was no statistically significant difference between restorative materials used (p=0.877. As regards the studied age group, patients aged from 1 to 4 years showed a significantly lower success rate when compared with 5-8 year-old children (p = 0.0428. Conclusion: The results suggest that the indirect pulp capping technique after incomplete excavation of demineralized dentin is a reliable technique to be adopted in deep lesions of primary teeth.

  20. 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.

  1. Evaluation of temperature variation in pulp chamber after high power diode laser irradiation ({lambda}=830 nm) on dental enamel: 'in vitro' study; Avaliacao da variacao da temperatura na camara pulpar apos a irradiacao de diodo laser de alta potencia de 830 nanometros em esmalte dental: estudo 'in vitro'

    Energy Technology Data Exchange (ETDEWEB)

    Macri, Rodrigo Teixeira

    2001-07-01

    The aim of this study was to observe the variation of temperature in the pulp chamber caused by irradiation of a commercial diode laser operating in continuous wave with wavelength 830 nm over the dental enamel. In the first part of this study, two types of tooth models were tested: 3,5 mm slice and whole tooth. In the second part, we irradiated the buccal si de of the enamel in 2 primary lower incisors from cattle with Opus 10 diode laser for 10 s with power levels of 1 W and 2 W, always using an absorber. Two thermocouples were used. The first one was inserted in the dentin wall closest to the irradiation site, while the second was inserted in the middle of the pulp chamber. It was observed that the thermocouples registered different temperatures. Always, the dentin thermocouple registered higher temperatures. Considering the dentin records, the irradiation of 1 W for 10 s can be safe for the pulp. Further studies must be developed related to the correct positioning of the thermocouples inside the pulp chamber. This was a first step of using diode laser in enamel, and in this study, we concluded that the Opus 10 diode laser shown to be safe for this use, with 1 W power for 10 S. (author)

  2. An in-vitro study to compare the temperature rise in the pulp chamber by direct method using three different provisional restorative materials.

    Science.gov (United States)

    Piplani, Ankita; Suresh Sajjan, M C; Ramaraju, A V; Tanwani, Tushar; Sushma, G; Ganathipathi, G; Jagdish, K; Agrawal, Anil

    2016-01-01

    The provisional restorative materials in fixed prosthodontics are basically bis-GMA resins which releases exothermic temperature while polymerization which can damage the pulp. Intrapulpal temperature exceeding 42.5°C found to result in irreversible damage to the pulp. The remaining thickness of dentine after tooth preparation control the conduction of heat released by the resins. (1) To quantify the temperature changes in the pulp chamber using different provisional restorative materials. (2) To evaluate the peak temperature time of different materials used. (3) To compare the intrapulpal temperature changes with a variation in the width of the finish line. Two intact mandibular molars were selected and designated as Specimen A and B. Tooth preparation was done to prepare a finish line of 1.2 mm and 1 mm width, respectively. Three provisional restorative materials were considered and they were grouped as Group I-Cool temp, Group II-Protemp-4, Group III-Integrity. A J thermocouple probe was placed into the pulp chamber to determine the rise in temperature. The temperature was recorded during polymerization at 30-s intervals until the peak temperature was reached. The same procedure was repeated for fabricating remaining provisional crowns. A total of 45 provisional crowns were fabricated for each specimen. Kruskal-Wallis test revealed that there was a significant difference in the temperature changes associated with the provisional restorative materials used. All the three provisional restorative materials were compared for 1.2 mm and 1 mm wide finish line. Integrity produced the highest temperature rise and the maximum temperature recorded was 40.2°C in 1.2 mm wide finish line. However, for a 1 mm wide finish line, Protemp-4 produced the highest temperature rise and the maximum temperature recorded was 40.3°C. It was observed that peak temperatures with Specimen B were more when compared with Specimen A. Cool temp showed least temperature rise in the pulp

  3. In vitro study of the pulp chamber temperature rise during light-activated bleaching

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    Thaise Graciele Carrasco

    2008-10-01

    Full Text Available This study evaluated in vitro the pulp chamber temperature rise induced by the light-activated dental bleaching technique using different light sources. The root portions of 78 extracted sound human mandibular incisors were sectioned approximately 2 mm below the cementoenamel junction. The root cavities of the crowns were enlarged to facilitate the correct placing of the sensor into the pulp chamber. Half of specimens (n=39 was assigned to receive a 35% hydrogen peroxide gel on the buccal surface and the other halt (n=39 not to receive the bleaching agent. Three groups (n=13 were formed for each condition (bleach or no bleach according to the use of 3 light sources recommended for dental bleaching: a light-emitting diode (LEDlaser system, a LED unit and a conventional halogen light. The light sources were positioned perpendicular to the buccal surface at a distance of 5 mm and activated during 30 s. The differences between the initial and the highest temperature readings for each specimen were obtained, and, from the temperature changes, the means for each specimen and each group were calculated. The values of temperature rise were compared using Kruskal-Wallis test at 1% significance level. Temperature rise varied significantly depending on the light-curing unit, with statistically significant differences (p0.01. When the bleaching agent was applied, there were significant differences among groups (p<0.01: halogen light induced the highest temperature rise (1.41±0.64ºC, and LED-laser system the lowest (0.33±0.12ºC; however, there was no difference between LED-laser system and LED unit (0.44±0.11ºC. LED and LED-laser system did not differ significantly from each other regardless the temperature rise occurred with or without bleaching agent application. It may be concluded that during light-activated tooth bleaching, with or without the bleaching agent, halogen light promoted higher pulp chamber temperature rise than LED unit and LED

  4. Combination of aligned PLGA/Gelatin electrospun sheets, native dental pulp extracellular matrix and treated dentin matrix as substrates for tooth root regeneration.

    Science.gov (United States)

    Chen, Gang; Chen, Jinlong; Yang, Bo; Li, Lei; Luo, Xiangyou; Zhang, Xuexin; Feng, Lian; Jiang, Zongting; Yu, Mei; Guo, Weihua; Tian, Weidong

    2015-06-01

    In tissue engineering, scaffold materials provide effective structural support to promote the repair of damaged tissues or organs through simulating the extracellular matrix (ECM) microenvironments for stem cells. This study hypothesized that simulating the ECM microenvironments of periodontium and dental pulp/dentin complexes would contribute to the regeneration of tooth root. Here, aligned PLGA/Gelatin electrospun sheet (APES), treated dentin matrix (TDM) and native dental pulp extracellular matrix (DPEM) were fabricated and combined into APES/TDM and DPEM/TDM for periodontium and dental pulp regeneration, respectively. This study firstly examined the physicochemical properties and biocompatibilities of both APES and DPEM in vitro, and further investigated the degradation of APES and revascularization of DPEM in vivo. Then, the potency of APES/TDM and DPEM/TDM in odontogenic induction was evaluated via co-culture with dental stem cells. Finally, we verified the periodontium and dental pulp/dentin complex regeneration in the jaw of miniature swine. Results showed that APES possessed aligned fiber orientation which guided cell proliferation while DPEM preserved the intrinsic fiber structure and ECM proteins. Importantly, both APES/TDM and DPEM/TDM facilitated the odontogenic differentiation of dental stem cells in vitro. Seeded with stem cells, the sandwich composites (APES/TDM/DPEM) generated tooth root-like tissues after being transplanted in porcine jaws for 12 w. In dental pulp/dentin complex-like tissues, columnar odontoblasts-like layer arranged along the interface between newly-formed predentin matrix and dental pulp-like tissues in which blood vessels could be found; in periodontium complex-like tissues, cellular cementum and periodontal ligament (PDL)-like tissues were generated on the TDM surface. Thus, above results suggest that APES and DPEM exhibiting appropriate physicochemical properties and well biocompatibilities, in accompany with TDM, could

  5. Influence of Biodentine® - A Dentine Substitute - On Collagen Type I Synthesis in Pulp Fibroblasts In Vitro.

    Science.gov (United States)

    Nikfarjam, Frangis; Beyer, Kim; König, Anke; Hofmann, Matthias; Butting, Manuel; Valesky, Eva; Kippenberger, Stefan; Kaufmann, Roland; Heidemann, Detlef; Bernd, August; Zöller, Nadja Nicole

    2016-01-01

    Preserving a patient's own teeth-even in a difficult situation-is nowadays preferable to surgical intervention and therefore promotes development of suitable dental repair materials. Biodentine®, a mineral trioxide aggregate substitute, has been used to replace dentine in a bioactive and biocompatible manner in both the dental crown and the root. The aim of our study was to evaluate the influence of Biodentine® on pulp fibroblasts in vitro. For this study, one to five Biodentine® discs with a diameter of 5.1mm were incubated in DMEM. To obtain Biodentine® suspensions the media were collected and replaced with fresh medium every 24h for 4 days. Primary pulp cells were isolated from freshly extracted wisdom teeth of 20-23 year old patients and incubated with the Biodentine® suspensions. Proliferation, cell morphology, cell integrity and cell viability were monitored. To evaluate the effect of Biodentine® on collagen type I synthesis, the secretion of the N-terminal domain of pro-collagen type I (P1NP) and the release of transforming growth factor-β1 (TGF-β1) were quantified. None of the Biodentine® suspensions tested influenced cell morphology, proliferation or cell integrity. The cell viability varied slightly depending on the suspension used. However, the concentrations of P1NP of all pulp fibroblast cultures treated for 24h with the moderate to high Biodentine® concentration containing suspensions of day 1 were reduced to 5% of the control. Furthermore, a significant TGF-β1 reduction was observed after treatment with these suspensions. It could be shown that Biodentine® is biocompatible. However, dissolved particles of the moderate to high concentrated Biodentine® suspensions 24h after mixing induce a significant reduction of TGF-β1 release and reduce the secretion of collagen type I of primary pulp fibroblasts.

  6. Temperature changes of pulp chamber during in vitro laser welding of orthodontic attachments.

    Science.gov (United States)

    Işman, Eren; Okşayan, Rıdvan; Sökücü, Oral; Üşümez, Serdar

    2014-01-01

    The use of lasers has been suggested for orthodontists to fabricate or repair orthodontic appliances by welding metals directly in the mouth. This work aimed to evaluate the temperature changes in the pulp chamber during welding of an orthodontic wire to an orthodontic molar band using Nd : YAG laser in vitro. A freshly extracted human third molar with eliminated pulpal tissues was used. J-type thermocouple wire was positioned in the pulp chamber. A conductor gel was used in the transferring of outside temperature changes to the thermocouple wire. An orthodontic band was applied to the molar tooth and bonded using light cured orthodontic cement. Twenty five mm length of 0.6 mm diameter orthodontic stainless steel wires was welded to the orthodontic band using Nd : YAG laser operated at 9.4 watt. Temperature variation was determined as the change from baseline temperature to the highest temperature was recorded during welding. The recorded temperature changes were between 1.8 and 6.8°C (mean: 3.3±1.1°C). The reported critical 5.5°C level was exceeded in only one sample. The results of this study suggest that intraoral use of lasers holds great potential for the future of orthodontics and does not present a thermal risk. Further studies with larger samples and structural analysis are required.

  7. Temperature Changes of Pulp Chamber during In Vitro Laser Welding of Orthodontic Attachments

    Science.gov (United States)

    İşman, Eren; Okşayan, Rıdvan; Sökücü, Oral; Üşümez, Serdar

    2014-01-01

    The use of lasers has been suggested for orthodontists to fabricate or repair orthodontic appliances by welding metals directly in the mouth. This work aimed to evaluate the temperature changes in the pulp chamber during welding of an orthodontic wire to an orthodontic molar band using Nd : YAG laser in vitro. A freshly extracted human third molar with eliminated pulpal tissues was used. J-type thermocouple wire was positioned in the pulp chamber. A conductor gel was used in the transferring of outside temperature changes to the thermocouple wire. An orthodontic band was applied to the molar tooth and bonded using light cured orthodontic cement. Twenty five mm length of 0.6 mm diameter orthodontic stainless steel wires was welded to the orthodontic band using Nd : YAG laser operated at 9.4 watt. Temperature variation was determined as the change from baseline temperature to the highest temperature was recorded during welding. The recorded temperature changes were between 1.8 and 6.8°C (mean: 3.3 ± 1.1°C). The reported critical 5.5°C level was exceeded in only one sample. The results of this study suggest that intraoral use of lasers holds great potential for the future of orthodontics and does not present a thermal risk. Further studies with larger samples and structural analysis are required. PMID:24550714

  8. Temperature Changes of Pulp Chamber during In Vitro Laser Welding of Orthodontic Attachments

    Directory of Open Access Journals (Sweden)

    Eren İşman

    2014-01-01

    Full Text Available The use of lasers has been suggested for orthodontists to fabricate or repair orthodontic appliances by welding metals directly in the mouth. This work aimed to evaluate the temperature changes in the pulp chamber during welding of an orthodontic wire to an orthodontic molar band using Nd : YAG laser in vitro. A freshly extracted human third molar with eliminated pulpal tissues was used. J-type thermocouple wire was positioned in the pulp chamber. A conductor gel was used in the transferring of outside temperature changes to the thermocouple wire. An orthodontic band was applied to the molar tooth and bonded using light cured orthodontic cement. Twenty five mm length of 0.6 mm diameter orthodontic stainless steel wires was welded to the orthodontic band using Nd : YAG laser operated at 9.4 watt. Temperature variation was determined as the change from baseline temperature to the highest temperature was recorded during welding. The recorded temperature changes were between 1.8 and 6.8°C (mean: 3.3 ± 1.1°C. The reported critical 5.5°C level was exceeded in only one sample. The results of this study suggest that intraoral use of lasers holds great potential for the future of orthodontics and does not present a thermal risk. Further studies with larger samples and structural analysis are required.

  9. The Hidden Treasure in Apical Papilla: The Potential Role in Pulp/Dentin Regeneration and BioRoot Engineering

    Science.gov (United States)

    Huang, George T.-J.; Sonoyama, Wataru; Liu, Yi; Liu, He; Wang, Songlin; Shi, Songtao

    2009-01-01

    Some clinical case reports have shown that immature permanent teeth with periradicular periodontitis or abscess can undergo apexogenesis after conservative endodontic treatment. A call for a paradigm shift and new protocol for the clinical management of these cases has been brought to attention. Concomitantly, a new population of mesenchymal stem cells residing in the apical papilla of permanent immature teeth recently has been discovered and was termed stem cells from the apical papilla (SCAP). These stem cells appear to be the source of odontoblasts that are responsible for the formation of root dentin. Conservation of these stem cells when treating immature teeth may allow continuous formation of the root to completion. This article reviews current findings on the isolation and characterization of these stem cells. The potential role of these stem cells in the following respects will be discussed: (1) their contribution in continued root maturation in endodontically treated immature teeth with periradicular periodontitis or abscess and (2) their potential utilization for pulp/dentin regeneration and bioroot engineering. PMID:18498881

  10. Evaluation of the temperature rise in pulp chamber during class V preparation with Er:YAG laser; Avaliacao da temperatura na camara pulpar durante preparo classe V com laser de Erbio:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Picinini, Leonardo Santos

    2001-07-01

    One of the major concerns regarding laser irradiation in the dentistry field is the overheating in dental tissue, specially pulpal tissue. A temperature raise over 5.5 deg C is considered to be harmful to its vitality. The current study evaluated the temperature increase in the pulp chamber, during class V preparation, performed with the laser Er:YAG in 36 bovine incisive extracted teeth. The samples were eroded on the outer side of the vestibular wall to obtain the dentinal thickness of 2.0 mm (group I), 1.0 mm (group II) and 0.5 mm (group III). Thermocouples were fixed to the inner part of the vestibular wall using thermal paste, through the palatine opening of the samples. Class V cavities were prepared in the vestibular side only in 1 mm{sup 2} thick dentins. Irradiation parameters used were: 500 mJ/10 Hz, 850 mJ/10 Hz and 1 000 mJ/10 Hz for all the groups. The results were processed by a microcomputer. This study showed that the temperature increased into the pulpal cavity reached around 3 deg C for the groups I (2,0 mm thick dentine) and II (1.0 mm thick dentine). In the group III (0.5 mm thick) temperature was around 5.5 deg C. Thus, the parameters used for cavity preparation, using Er:YAG laser, were safe in relation to the temperature raise for dentinal thickness of 1,0 and 2,0 mm; in 0.5 mm thick dentins, temperature increase reached 5.5 deg C and an appropriate correction in the laser parameters was necessary. (author)

  11. [The effect of Kaviner and the smear layer on dentin permeability of permanent teeth in children].

    Science.gov (United States)

    Tadmiscija, H; Kobaslija, S; Ganibegović, M; Jusufagić, H; Huseinbegović, A

    1996-01-01

    The dentin permeability is defined as a moving of fluid, of chemical substances and microbial products as well through the dentin. The clinical protection of children permanent teeth in other words the protection of pulp-dentin complex after their preparation makes a big problem into the restorative stomatology. Caviner is one of the newer means which is used in the protection of pulp-dentin complex which represents the components of powder dispersing within the ethyl-acetate mixture of polystirol. The important variable in this study is the presence or absence of smearing layer which has the important influence onto the dentin permeability. In order to confirm the Caviner and smearing layer working onto the dentin permeability of the children permanent teeth in vitro experiment was designed. We used for it the dentin disks made of the intact first premolar, extracted because of orthodontic reasons at the ten years old children. They were put into the split chamber which represents a part of apparatus made at our Faculty, which is, in fact, a modified apparatus which was formed by prof. D.H. Pashley (Georgia, USA), and it is used for measuring of dentin permeability with the help of hydraulic conductance (Lp) of dentin. The dentin permeability is expressed by the hydraulic conductance term, but the measures are still expressed as the Lp percentage maximum because of better survey of results. Comparing the obtained results with the other authors results we have come to the similar conclusions, and that is in fact, that the smearing layer significantly reduces the dentin permeability, and that the Caviner, as the other layners, reduces the dentin permeability. If we compare the reduction of dentin permeability at the dentin covered with the smearing layer and with the Caviner, it has been noticed that the smearing layer reduces more significantly. It should be accented that the Caviner reduces the dentin permeability less than the most earlier researched means for

  12. Dentin dysplasia type I : Five cases within one family

    NARCIS (Netherlands)

    Kalk, WWI; Batenburg, RHK; Vissink, A

    1998-01-01

    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

  13. Pathological studies of cheek teeth apical infections in the horse: 1. Normal endodontic anatomy and dentinal structure of equine cheek teeth.

    Science.gov (United States)

    Dacre, I T; Kempson, S; Dixon, P M

    2008-12-01

    Morphological examinations were performed on 100 normal equine cheek teeth (CT) of 1-12 years dental age (i.e. time since eruption), using gross examination, dissection microscopy, computerised axial tomography, and decalcified and undecalcified histology. The CT in Triadan 07-10 positions consistently had five pulp horns, but the 06 CT had an additional pulp horn more rostrally. Mandibular and maxillary Triadan 11s had six and seven pulp horns, respectively. Sections of CT taken 2-6mm below the occlusal surface (variation due to normal undulating occlusal surface) showed the presence of pulp in up to 50% of individual maxillary CT pulp horns, and in up to 25% of individual mandibular CT pulp horns. The histological appearances of primary and secondary dentine were described and it is proposed that the type of dentine present most centrally in every pulp chamber examined, currently termed tertiary dentine, should be re-classified as irregular secondary dentine, and that the term tertiary dentine be reserved for the focal areas of dentine laid down following insult to dentine or pulp.

  14. Direct pulp capping effect with experimentally developed adhesive resin systems containing reparative dentin-promoting agents on rat pulp: mixed amounts of additives and their effect on wound healing.

    Science.gov (United States)

    Taira, Yoshihisa; Shinkai, Koichi; Suzuki, Masaya; Kato, Chikage; Katoh, Yoshiroh

    2011-07-01

    This study examined the wound-healing process of exposed rat pulp when treated with experimental adhesive resin systems. The experimental direct pulp capping adhesive resin systems were composed of primer-I, primer-II and an experimental bonding agent. Primer-I was Clearfil SE Bond (CSE) primer containing 1.0 or 5.0 wt% CaCl(2), and primer-II was CSE primer containing 0.1, 1.0 or 5.0 wt% compound of equal mole of pA and pB with synthetic peptides derived from dentin matrix protein 1 (DMP1). Primer-I containing 1.0 and 5.0 wt% CaCl(2) was assigned to the experimental groups 1-3 and 4-6, respectively. Primer-II containing 0.1, 1.0 or 5.0 wt% compound of pA and pB was assigned to the experimental groups 1 and 4, 2 and 5, and 3 and 6, respectively. In all experimental groups, CSE bond containing 10 wt% hydroxyapatite powder was used as the experimental bonding agent. The positive control teeth were capped with calcium hydroxide preparation (Dycal), and the negative control teeth were capped with CSE. The specimens were alternately stained with Mayer's H&E and the enhanced polymer one-step staining methods. Experimental groups 1, 4, 5 and 6 showed a higher level of reparative dentin formation compared to the negative control 14 days postoperatively. At 28 days postoperatively, all experimental groups showed the formation of extensive reparative dentin, and experimental groups 4, 5 and 6 demonstrated similar dentin bridge formation as that of the positive control. How quickly reparative dentin formation occurs may depend on the concentration of CaCl(2) and the compound of pA and pB in the experimental primer.

  15. Potential Role of Dentin Sialoprotein by Inducing Dental Pulp Mesenchymal Stem Cell Differentiation and Mineralization for Dental Tissue Repair

    OpenAIRE

    Zhi Chen; Shuo Chen; Li-An Wu; Guo-Hua Yuan; Guo-Bin Yang

    2010-01-01

    Introduction: Dentin sialoprotein (DSP) is a dentin extracellular matrix protein, a unique marker of dentinogenesis and plays a vital role in odontoblast differentiation and dentin mineralization. Recently, studies have shown that DSP induces differentiation and mineralization of periodontal ligament stem cells and dental papilla mesenchymal cells in vitro and rescues dentin deficiency and increases enamel mineralization in animal models.The hypothesis: DSP as a nature therapeutic agent stimu...

  16. Electronomicroscopic evaluation of the microlesional aspects in the pulp dentinal complex after repeated whitening therapy

    Science.gov (United States)

    Bodea, Rodica; Jianu, Rodica; Marchese, Cristian; Vasile, Liliana

    2012-06-01

    The aim of this study was to examine cellular and matriceal dynamics within pulp tissue of the teeth with repeated bleaching. Material and method - The study was made on 25 patients aged between 15 and 45, to whom bleaching method of the premolars with indication of extraction in orthodontic purposes was applied. None of the subjects smoked and throughout the investigation no antibiotics had been used. We initiated an intensive oral hygiene program, and we removed the supragingival and subgingival deposits. Oral hygiene and the gingival health were evaluated before every session of bleaching. During each visit the dentition was cleaned professionally and if needed the subjects were reinstucted in proper oral hygiene. After 3 and 5 successive bleachings of the teeth, we removed the dental pulps and we extracted the premolars. The pulpal biopsies were fixed in buffed formaldehyde 10% for 48 hours, then paraffinized, sectioned at 3-5 μ and stained with topographic, H&E and trichrome stained. For the electonomicroscopic study we used the Lehner technique to process the biopsies (n=3) after the reinclusion of the pieces from the paraffine blocks in Epon, postfixated in buffered glutaraldehyde, micro sectioned at 0,5 μ, contrastated with Pb citrate (stained) and examination in transmission electronic microscopy with Philips microscope. Results - At cellular and matriceal level we observed a marked collagen fibrillogenesis in the presence of active fibroblasts, with well developed cellular organites and fibroclastic aspects which suggest matriceal active repair. The microvascular network presents an activated endothelium with turgescent endothelial cells, with intracitoplasmatic resorbtion vacuols, well developed Golgi Complex. Conclusion - We interpreed the cell - matriceal lesions in the context of the acute inflammatory process in the first lesional phase and chronic scleroatrophic process after successive bleaching.

  17. Effect of low-level laser therapy (λ780 nm) on the mechanically damaged dentin-pulp complex in a model of extrusive luxation in rat incisors.

    Science.gov (United States)

    de Santana, Dandara Andrade; Fonseca, Gabriela Ferraz; Ramalho, Luciana Maria Pedreira; Rodriguez, Tânia Tavares; Aguiar, Marcio Cajazeira

    2017-08-19

    In order to regenerate the dental pulp, many strategies have been developed as phototherapy. In the pulp repair, we do not know if gallium-aluminum-arsenide (GaAlAs) laser preserves the primary odontoblasts or stimulates the formation of more dentin matrix when dental pulp is damaged. The aim of the present study was to examine the effect of laser phototherapy (λ780 nm) on vascularization, inflammation, density of the primary odontoblast layer, and formation of reactionary and reparative dentin in the dental pulp by provoking extrusion of the rat incisor. The upper incisors were extruded 3 mm and then repositioned into their original sockets followed by a laser irradiation of the palatal mucosa (λ = 780 nm; p = 70 mW; CW; 4.2 J/cm(2); 60 s) every 48 h. Non-traumatized and/or non-irradiated incisors were used as the controls. At 8 and 30 days after surgery, incisors were processed for histological and histomorphometric analysis. Morphological analysis revealed no differences in vascularization between groups, but showed discrete inflammation in some non-irradiated and injured specimens, which correlated with a more irregular reparative dentin. The density of primary odontoblasts in the groups treated with lasers was higher when compared to non-irradiated groups, but no statistically significant difference between groups (p > 0.05). The thickness of the tertiary dentin was increased in both traumatized groups with no statistically significant difference between non-irradiated and irradiated groups (p > 0.05).The present findings revealed that the GaAlAs laser induced small changes on dentin-pulp complex, with more regular dentin matrix in the irradiated dental pulps.

  18. In-vitro Study on Temperature Changes in the Pulp Chamber Due to Thermo-Cure Glass Ionomer Cements

    Science.gov (United States)

    van Duinen, Raimond NB; Shahid, Saroash; Hill, Robert

    2016-01-01

    The application of the Glass Ionomer Cements in clinical dentistry is recommended due to properties such as fluoride release, chemical adhesion to tooth, negligible setting shrinkage, and coefficient of thermal expansion close to tooth, low creep, and good color stability. However, the cement is vulnerable to early exposure to moisture due to slow setting characteristics. The uses of external energy such as ultrasound and radiant heat (Thermo-curing) have been reported to provide acceleration of the setting chemistry and enhance physical properties. Aim: The aim of this in vitro study was to analyze temperature changes in the pulpal chamber when using radiant heat to accelerate the setting of GICs. Material and Methods:The encapsulated GIC Equia Forte was used for this study. The temperature changes in the pulp were measured using thermocouple in the cavities which were 2,6 and 4,7mm deep with and without filling. Results:The results showed that a temperature rise (ΔT) in the pulp chamber was 3,7°C. ΔT for the 2.6mm and 4.7mm deep cavity and without placing any restoration the temperature was 4,2°C and 2,6°C respectively. After the restoration has been placed, the ΔT range in the pulp chamber was lower ranging from 1.9°C to 2.4°C. Conclusion: It could be concluded that Thermo-curing of the GIC during the setting is safe for the pulp and can be recommended in clinical practice. PMID:28275275

  19. Effect of an Er,Cr:YSGG laser on water perfusion in human dentine.

    Science.gov (United States)

    Adu-Arko, Ampong Y; Sidhu, Sharanbir K; McCabe, John F; Pashley, David H

    2010-10-01

    Changes in fluid perfusion through tubules may affect the sensitivity of exposed and restored dentine. The rate of perfusion is dependent on the structure and composition of dentine, particularly at the surface. This work analyzed the effect of treatment with an Erbium, Chromium-doped: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser on dentine perfusion. Extracted molars were sectioned above the mid-coronal portion, and below the cemento-enamel junction, to create crown segments. The pulp was extirpated and the dentine treated with the Er,Cr:YSGG laser, a diamond bur or sandpaper. Each specimen was mounted, with the pulp chamber oriented upwards, on a petri-dish cover in order to permit a tube filled with water to be connected to the pulp. Movement of the water meniscus over 24 h provided a measurement of the volume of water that filtered across the dentine. The dishes contained water to provide a moist environment in the relevant specimens, or were left dry to provide dry conditions. Specimens were perfused for 24 h with water pressures ranging from 20 to 60 cm. The results (in μl mm(-2) d(-1) ) showed a significant difference in the perfusion rate between treatments. The difference between perfusion in wet and dry conditions was highly significant. Laser and bur treatment of dentine significantly affected perfusion, which was higher in the former than in the latter. Therefore, laser-treated dentine may be more sensitive than bur-cut dentine.

  20. Dentin sialophosphoprotein knockout mouse teeth display widened predentin zone and develop defective dentin mineralization similar to human dentinogenesis imperfecta type III.

    Science.gov (United States)

    Sreenath, Taduru; Thyagarajan, Tamizchelvi; Hall, Bradford; Longenecker, Glenn; D'Souza, Rena; Hong, Sung; Wright, J Tim; MacDougall, Mary; Sauk, John; Kulkarni, Ashok B

    2003-07-01

    Dentin sialophosphoprotein (Dspp) is mainly expressed in teeth by the odontoblasts and preameloblasts. The Dspp mRNA is translated into a single protein, Dspp, and cleaved into two peptides, dentin sialoprotein and dentin phosphoprotein, that are localized within the dentin matrix. Recently, mutations in this gene were identified in human dentinogenesis imperfecta II (Online Mendelian Inheritance in Man (OMIM) accession number 125490) and in dentin dysplasia II (OMIM accession number 125420) syndromes. Herein, we report the generation of Dspp-null mice that develop tooth defects similar to human dentinogenesis imperfecta III with enlarged pulp chambers, increased width of predentin zone, hypomineralization, and pulp exposure. Electron microscopy revealed an irregular mineralization front and a lack of calcospherites coalescence in the dentin. Interestingly, the levels of biglycan and decorin, small leucine-rich proteoglycans, were increased in the widened predentin zone and in void spaces among the calcospherites in the dentin of null teeth. These enhanced levels correlate well with the defective regions in mineralization and further indicate that these molecules may adversely affect the dentin mineralization process by interfering with coalescence of calcospherites. Overall, our results identify a crucial role for Dspp in orchestrating the events essential during dentin mineralization, including potential regulation of proteoglycan levels.

  1. In-vivo Generation of Dental Pulp-Like Tissue Using Human Pulpal Stem Cells, a Collagen Scaffold and Dentin Matrix Protein 1 Following Subcutaneous Transplantation in Mice

    Science.gov (United States)

    Prescott, Rebecca S.; Alsanea, Rajaa; Fayad, Mohamed I.; Johnson, Bradford R.; Wenckus, Christopher S.; Hao, Jianjun; John, Asha S.; George, Anne

    2008-01-01

    The presence of a perforation is known to significantly compromise the outcome of endodontic treatment. One potential use of regenerative endodontic therapy may be the repair of root canal perforations. In addition to nutrients and systemic in-situ interactions, the three main components believed to be essential for tissue regeneration are: stem cells, scaffold, and growth factors. This study investigated the role of each component of the tissue engineering triad in the organization and differentiation of Dental Pulp Stem Cells (DPSCs) in a simulated furcal perforation site using a mouse model. Collagen served as the scaffold and dentin matrix protein 1 (DMP1) was the growth factor. Materials were placed in simulated perforation sites in dentin slices. MTA was the control repair material. At six weeks, the animals were sacrificed and the perforation sites were evaluated by light microscopy and histological staining. Organization of newly derived pulp tissue was seen in the group containing the triad of DPSCs, a collagen scaffold, and DMP1. The other four groups did not demonstrate any apparent tissue organization. Under the conditions of the present study, it may be concluded that the triad of DPSCs, a collagen scaffold, and DMP1 can induce an organized matrix formation similar to that of pulpal tissue, which may lead to hard tissue formation. PMID:18358888

  2. Topography of the pulp chamber in the maxillary primary molars of a Tunisian children

    Directory of Open Access Journals (Sweden)

    Chiraz Baccouche

    2013-01-01

    Conclusion: Mesiodistal dimension of the pulp cavity is not proportional to that of the dental crown. Endodontic access cavity have to be shifted to the distal and vestibular sides from the first to the second upper molar.

  3. Disruption of Tgfbr2 in odontoblasts leads to aberrant pulp calcification.

    Science.gov (United States)

    Ahn, Y H; Kim, T H; Choi, H; Bae, C H; Yang, Y M; Baek, J A; Lee, J C; Cho, E S

    2015-06-01

    Transforming growth factor β (TGF-β) signaling has been implicated in dentin formation and repair; however, the molecular mechanisms underlying dentin formation remain unclear. To address the role of TGF-β signaling in dentin formation, we analyzed odontoblast-specific Tgfbr2 conditional knockout mice. The mutant mice had aberrant teeth with thin dysplastic dentin and pulpal obliteration, similar to teeth from human patients with dentinogenesis imperfecta type II and dentin dysplasia. In mutant, the odontoblasts lost their cellular polarity, and matrix secretion was disrupted after mantle dentin formation. As a consequence, the amount of predentin decreased significantly, and an ectopic fibrous matrix was formed below the odontoblast layer. This matrix gradually calcified and obliterated the pulp chamber with increasing age. Immunohistochemistry revealed decreased expression of alkaline phosphatase in mutant odontoblasts. In mutant dentin, Dsp expression was reduced, but Dmp1 expression increased significantly. Collagen type I, biglycan, and Dsp were expressed in the ectopic matrix. These results suggest that loss of responsiveness to TGF-β in odontoblasts results in impaired matrix formation and pulpal obliteration. Our study indicates that TGF-β signaling plays an important role in dentin formation and pulp protection. Furthermore, our findings may provide new insight into possible mechanisms underlying human hereditary dentin disorders and reparative dentin formation.

  4. Histological effects of enamel matrix derivative on exposed dental pulp

    Directory of Open Access Journals (Sweden)

    Popović-Bajić Marijana

    2015-01-01

    Full Text Available Introduction. Direct pulp capping procedure is a therapeutic application of a drug on exposed tooth pulp in order to ensure the closure of the pulp chamber and to allow the healing process to take place. Objective. The aim of this study was to examine the histological effects of Emdogain® on exposed tooth pulp of a Vietnamese pig (Sus scrofa verus. Methods. The study comprised 20 teeth of a Vietnamese pig. After class V preparation on the buccal surfaces of incisors, canines and first premolars, pulp was exposed. In the experimental group, the perforations were capped with Emdogain® (Straumann, Basel, Switzerland, while in the control group pulp capping was performed with MTA® (Dentsply Tulsa Dental, Johnson City, TN, USA. All cavities were restored with glass-ionomer cement (GC Fuji VIII, GC Corporation, Tokyo, Japan. The observational period was 28 days, after which the animal was sacrificed and histological preparations were made. A light microscope was used to analyze dentin bridge formation, tissue reorganization and inflammation, and the presence of bacteria in the pulp. Results. The formation of dentin bridge was observed in the experimental and control groups. Inflammation of the pulp was mild to moderate in both groups. Angiogenesis and many odontoblast-like cells, responsible for dentin bridge formation, were observed. Necrosis was not observed in any case, nor were bacteria present in the pulp. Conclusion. Histological analysis indicated a favorable therapeutic effect of Emdogain® Gel in direct pulp capping of Vietnamese pigs. Pulp reaction was similar to that of MTA®. [Projekat Ministarstva nauke Republike Srbije, br. ON172026

  5. A novel type of developmental dentin defect.

    Science.gov (United States)

    Lukinmaa, P L; Waltimo, J; Hölttä, P; Risteli, L; Risteli, J; Alaluusua, S

    1996-01-01

    We describe a developmental dentin disorder distinct from dentin defects characterized thus far. The proband was a 9-year-old boy who was the only family member known to be affected in five generations. The dental defect was not associated with any general disease or developmental disorder. The teeth appeared normal with the exception of the pink hue seen in some primary teeth. Radiographs showed pathological resorption of primary teeth and abnormally shaped pulp chambers and denticles in permanent teeth. Root canals were wide in developing teeth, but appeared thin in erupted teeth. Histological examination of two primary molars revealed canal-like defects in dentin. In the crown, the canals appeared as clusters, which alternated with columns of normal tubular dentin, and in the virtually atubular root dentin they were haphazardly distributed. Scanning electron microscopic examination confirmed the distribution pattern of the canals. In transmission electron microscopy, the defects were found to contain symmetrically banded, segmental collagenous structures. The canal contents immunostained with antibodies to the N-terminal propeptide of type I procollagen, suggesting retention of the propeptide extension in type I collagen. Whereas type III collagen reactivity was barely detectable in the canal region, staining for type V collagen and the non-fibril-forming type VI collagen was strong. The findings imply that the pathogenesis of the defect could be related to a local failure of odontoblasts to produce normal dentin matrix.

  6. Hydration of Biodentine, Theracal LC, and a prototype tricalcium silicate-based dentin replacement material after pulp capping in entire tooth cultures.

    Science.gov (United States)

    Camilleri, Josette; Laurent, Patrick; About, Imad

    2014-11-01

    The calcium-releasing ability of pulp-capping materials induces pulp tissue regeneration. Tricalcium silicate-based materials produce calcium hydroxide as a by-product of hydration. Assessment of hydration and calcium ion leaching is usually performed on samples that have been aged in physiological solution for a predetermined period of time. The hydration and activity of the materials in vivo may not be similar to those displayed in vitro because of insufficient fluid available in contact with dentin. The aim of this research was the assessment of hydration of Biodentine, Theracal LC, and a prototype radiopacified tricalcium silicate-based material after pulp capping and to compare it with direct hydration in an aqueous solution. The extent of hydration of Biodentine, Theracal LC, and a prototype radiopacified tricalcium silicate-based material with a similar composition to Biodentine but not incorporating the additives was assessed by scanning electron microscopy and energy dispersive spectroscopy of polished specimens after being allowed to hydrate in Hank's balanced salt solution for 14 days. The extent of hydration was compared with material hydration when used as direct pulp capping materials by using a tooth culture model. Material activity was also assessed by x-ray diffraction analysis to investigate the deposition of calcium hydroxide by the materials, and calcium ion leaching in Hank's balanced salt solution was assessed by ion chromatography. Biodentine and the prototype tricalcium silicate cement hydrated and reaction by-products were deposited in the cement matrix both after pulp capping and when incubated in an aqueous solution. Calcium hydroxide was formed, and calcium ions were leached in solution. Theracal LC hydration was incomplete because of the limited moisture diffusion within the material. Thus, no calcium hydroxide was produced, and a lower calcium ion leaching was recorded. Theracal LC had a heterogeneous structure with large unhydrated

  7. Modeling of thermal and optical effects in dental pulp during the irradiation with neodymium and diode lasers; Modelagem dos efeitos termicos e opticos na polpa dentaria durante a irradiacao com os lasers de diodo de neodimio

    Energy Technology Data Exchange (ETDEWEB)

    Farhat, Patricia Bahls de Almeida

    2003-07-01

    During the development of applications of high intensity lasers in the enamel and dentine, adverse thermal effects into the entire dental structure, including the pulp, must be verified. The measurement of the temperature in the intact pulp, however, is not a solved problem. For this purpose, models have been used frequently, using extracted teeth, with pulpal cavities filled with materials that simulate only thermal properties of the pulp. Current models, however, do not simulate optical properties of the pulp, not taking the remaining radiation in the pulp chamber into account. The aim of this study was to verify if the remaining radiation from neodymium and diode lasers that reach the pulp chamber, at the models using extracted bovine teeth, can cause local thermal effects. For this purpose, two models were developed, using extracted bovine teeth with their pulp chambers filled with water (simulating pulp thermal characteristics) without (model 1) and with (model 2) an optical absorbent. Models were radiated with 1 W. The obtained results show that, for both lasers, the temperature rise in model 2 pulp chamber is: up to 11 % higher than in the model 1 when the enamel is radiated; and up to 37% higher than in the model 1 when dentine is radiated (1 mm from the pulp), indicating that the level of the remaining radiation is relevant for the construction of models excited by the neodymium and diode lasers. (author)

  8. Regeneration of dentin-pulp complex with cementum and periodontal ligament formation using dental bud cells in gelatin-chondroitin-hyaluronan tri-copolymer scaffold in swine.

    Science.gov (United States)

    Kuo, Tzong-Fu; Huang, An-Ting; Chang, Hao-Hueng; Lin, Feng-Huei; Chen, San-Tai; Chen, Rung-Shu; Chou, Cheng-Hung; Lin, Hsin-Chi; Chiang, Han; Chen, Min-Huey

    2008-09-15

    The purpose of this study is to use a tissue engineering approach for tooth regeneration. The swine dental bud cells (DBCs) were isolated from the developing mandibular teeth, expanded in vitro, and cultured onto cylinder scaffold gelatin-chrondroitin-hyaluronan-tri-copolymer (GCHT). After culturing in vitro, the DBCs/GCHT scaffold was autografted back into the original alveolar socket. Hematoxylin and eosin (H&E) staining combined with immunohistochemical staining were applied for identification of regenerated tooth structure. After 36-week post-transplantation, tooth-like structures, including well-organized dentin-pulp complex, cementum, and periodontal ligament, were evident in situ in two of six experimental animals. The size of the tooth structure (1 x 0.5 x 0.5 cm(3) and 0.5 x 0.5 x 0.5 cm(3) size) appeared to be dictated by the size of the GCHT scaffold (1 x 1 x 1.5 cm(3)). The third swine was demonstrated with irregular dentin-bony like calcified tissue about 1 cm in diameter without organized tooth or periodontal ligament formation. The other three swine in the experimental group showed normal bone formation and no tooth regeneration in the transplantation sites. The successful rate of tooth regeneration from DBCs/GCHT scaffolds' was about 33.3%. In the control group, three swine's molar teeth buds were removed without DBCs/GCHT implantation, the other three swine received GCHT scaffold implants without DBCs. After evaluation, no regenerated tooth was found in the transplantation site of the control group. The current results using DBSs/GCHT scaffold autotransplantation suggest a technical breakthrough for tooth regeneration.

  9. Dental pulp response to bacterial cell wall material.

    Science.gov (United States)

    Warfvinge, J; Dahlén, G; Bergenholtz, G

    1985-08-01

    Lipopolysaccharides (LPS) from Bacteroides oralis and Veillonella parvula and cell wall material from Lactobacillus casei were studied for their capacity to induce leukocyte migration in the dental pulp and in an implanted wound chamber. Three adult monkeys were challenged using lyophilized material sealed into buccal Class V cavities prepared in dentin. Pulp tissue responses were observed histologically eight and 72 hours after initiation of the experiment. Subjacent to cut dentinal tubules, bacterial materials induced polymorphonuclear leukocyte (PMN's) infiltration in the pulp tissue of the majority of test teeth examined. Responses were similar for the three bacterial test materials at both time periods. Topical applications of bovine serum albumin (BSA), used as a control, induced significantly less accumulation of PMN's. Assessments of induced exudate volumes and leukocyte densities in chambers implanted in rats showed comparable rankings with pulpal experiment between test (i.e., bacterial) and control (BSA) materials. Analysis of the data indicates that high-molecular-weight complexes of bacterial cell walls may adversely affect pulpal tissue across freshly exposed dentin.

  10. The effects of phosphoric acid, sodium hypochlorite, ferric oxalate and Scotchbond Multipurpose on the rate of pressure change across dentine: a laboratory study.

    Science.gov (United States)

    Ng, L P; Wilson, P R

    2005-06-01

    The aim of this study was to investigate the consequences of dentine treatment on dentine permeability of crown preparations treated with phosphoric acid, sodium hypochlorite (NaOCl), and then ferric oxalate (Sensodyne sealant) or bis-phenol-A-diglycidyldimethacrylate (BIS-GMA) and hydroxyethylmethacrylate (HEMA) resin combination (Scotchbond Multipurpose). Thirty human premolars received full crown preparations (stage A), were then acid etched (stage B) and subsequently the pulp chamber flushed with NaOCl (stage C). They were then randomly assigned to two groups: group 1 was treated with Scotchbond Multipurpose and group 2 with 6% ferric oxalate (Sensodyne sealant) (stage D). Both groups were acid etched a second time (stage E) as the final step in the sequence. The rise in pressure in the pulp chamber because of the transmission of saline from the pressure chamber through cut dentine was recorded by a pressure transducer after each of the stages described (A to E). The mean rate of pressure change across dentine (Pa s(-1)) for each measurement point (A to E) (n = 30) were A = 2.3; B = 9.8; C = 16; D = 2.1; E = 3.1. Acid etching and NaOCl were both effective in producing significant increases in the rate of pressure change across dentine (P Sensodyne sealant and Scotchbond Multipurpose are both effective dentine sealants and there is no significant difference (P > 0.05) in their abilities in sealing dentine. Acid etching-sealed dentine produced a significant increase in the rate of pressure change across dentine (P < 0.05). The sealing of dentine appears to be a sensible consideration following crown preparations on vital teeth.

  11. Effect of cleaning methods on bond strength of self-etching adhesive to dentin

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    Juliana Delatorre Bronzato

    2016-01-01

    Full Text Available Aim: The aim of this study was to investigate the influence of cleaning methods to remove zinc oxide-eugenol-based root canal sealer (Endomethasone on the bond strength of the self-etching adhesive to dentin. Materials and Methods: Twenty crowns of bovine incisors were cut to expose the pulp chamber. A zinc oxide- and eugenol-based sealer was placed for 10 min in contact with the pulp chamber dentin. Specimens were divided into four groups according to the cleaning method of dentin used: G1, no root canal sealer (control; G2, 0.9% sodium chlorite (NaCl; G3, ethanol; and G4, followed by diamond drill. After cleaning, the teeth were restored with composite resin and Clearfil SE Bond. All specimens were sectioned to produce rectangular sticks and dentin/resin interface was submitted to microtensile bond testing. The mean bond strengths were analyzed using ANOVA/Tukey (α = 0.05. Results: G3 and G4 showed bond strengths similar to the G1 (P > 0.05. A significant decrease in the bond strength in the G2 was observed (P < 0.05. G1, G3, and G4, the predominant failure mode was the mixed type. The prevalence of adhesive failure mode was verified in the G2. Conclusion: The cleaning methods affected the bond strength of the self-etching adhesive to dentin differently.

  12. Effect of Er:YAG laser on dentin bonding durability under simulated pulpal pressure.

    Science.gov (United States)

    Bakry, Ahmed Samir; Nakajima, Masatoshi; Otsuki, Masayuki; Tagami, Junji

    2009-10-01

    To evaluate the effects of Er:YAG laser ablation on the microtensile bond strength and the nanoleakage of Er:YAG-lased dentin bonded to a self-etching adhesive system with and without pulpal pressure. Twenty flat dentin surfaces were obtained from extracted molars. Ten specimens were irradiated by Er:YAG laser, other specimens (control group) were ground using #600 SiC paper. Direct communication to the pulp chamber was created by cutting at a level approximately 1 mm below the cementoenamel junction and parallel to the occlusal surface. The experimental groups were exposed to a simulated pulpal pressure of 15 cm H2O. Each specimen was restored using an adhesive and a photocured composite. The specimens were then sectioned vertically to obtain dentin/adhesive slabs. Ninety-six slabs were prepared for microtensile bond testing. Sixty-four slabs were immersed in ammoniacal silver nitrate tracer solution for 18 h, then rinsed thoroughly, and immersed in photodeveloping solution for 6 h prior to their examination by FE-SEM. The method of dentin preparation and the pulpal pressure storage condition significantly affected the microTBS, while the storage duration did not (p < 0.05). The nanoleakage patterns observed in the dentin/bond interface differed depending on whether the dentin was conventionally prepared or ablated by Er:YAG laser. Er:YAG laser ablation to dentin adversely affected the microTBS and the sealing ability of SE Bond bonded to dentin under simulated pulpal condition.

  13. Bioceramic/Poly (glycolic-poly (lactic acid composite induces mineralized barrier after direct capping of rat tooth pulp tissue

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    Alfonso Gala-Garcia

    2010-03-01

    Full Text Available The aim of this study was to observe the histopathological pulp response following direct pulp capping of mechanically exposed teeth in rats with a composite of beta-tricalcium phosphate-hydroxyapatite bioceramic (BC and poly (glycolic-poly (lactic acid (PLGA material or a calcium hydroxide [Ca(OH2] material, compared to BC alone and a negative control of water. Pulp of the maxillary molars was exposed, followed by capping with the experimental material. The pulpal tissue response was assessed post-operatively at 1, 7, 14 and 30 d, followed by histological analysis. The Ca(OH2 group exhibited severe acute inflammatory cell infiltration at day 14. However after 30 d, a new hard tissue with macro porous obliteration of the pulp chamber and a characteristic necrotic area had appeared. BC and Ca(OH2 capping were associated with moderate inflammation and dentinal bridge similar. Meanwhile, in the BC/PLGA composite group, there was moderate inflammatory infiltrate and formation of a dense and complete dentinal bridge. In conclusion, the BC/PLGA composite material showed a large zone of tertiary dentin, and effectively reorganized the dentin-pulp complex.

  14. Pulp development, repair, and regeneration: challenges of the transition from traditional dentistry to biologically based therapies.

    Science.gov (United States)

    Schmalz, Gottfried; Smith, Anthony J

    2014-04-01

    The traditional concept of replacing diseased tooth/pulp tissues by inert materials (restoration) is being challenged by recent advances in pulp biology leading to regenerative strategies aiming at the generation of new vital tissue. New tissue formation in the pulp chamber can be observed after adequate infection control and the formation of a blood clot. However, differentiation of true odontoblasts is still more speculative, and the approach is largely limited to immature teeth with open apices. A more systematic approach may be provided by the adoption of the tissue engineering concepts of using matrices, suitable (stem) cells, and signaling molecules to direct tissue events. With these tools, pulplike constructs have already been generated in experimental animals. However, a number of challenges still remain for clinical translation of pulp regeneration (eg, the cell source [resident vs nonresident stem cells, the latter associated with cell-free approaches], mechanisms of odontoblast differentiation, the pulp environment, the role of infection and inflammation, dentin pretreatment to release fossilized signaling molecules from dentin, and the provision of suitable matrices). Transition as a process, defined by moving from one form of "normal" to another, is based not only on the progress of science but also on achieving change to established treatment concepts in daily practice. However, it is clear that the significant recent achievements in pulp biology are providing an exciting platform from which clinical translation of dental pulp regeneration can advance. Copyright © 2014. Published by Elsevier Inc.

  15. Morphological Study Of Border Area Of Pulp-Capping Materials And Er:YAG Laser Prepared Hard Dental Surface.

    Science.gov (United States)

    Stefanova, Vessela P; Tomov, Georgi T; Tsanova, Snezhana Ts

    2015-01-01

    Vital pulp therapy involves biologically based therapeutic activities aimed at restoring health and preserving the vitality of cariously or traumatically damaged pulp. Adaptation of pulp-capping materials to the prepared tooth surface may be the key to the success of biological tooth treatment. To investigate the area of adaptation of synthetic tricalcium silicate cement, calcium hydroxide cement and mineral trioxide-aggregate to the dentin surface, prepared with the help of Er:YAG dental laser. Four extracted human tooth cavities were prepared with the help of Er:YAG dental laser (LiteTouch, Syneron, Israel), establishing microcommunication with the pulp chamber less than 1 mm in diameter. As pulp-capping materials in the cavities we used tricalcium silicate cement (Biodentine, Septodont, France), calcium hydroxide cement (Dycal) and mineral-trioxide aggregate (ProRoot MTA), stirred and administered according to manufacturers' instructions. The first material fills the whole cavity and the other two are spread in a thin layer and sealed with glass ionomer cement. Thus prepared, the samples were left for three days at 37°C in humidified environment. The samples were prepared for scanning electron microscopy (SEM) by standard methodology. The border area surfaces of the materials and the dentin were scanned using electron microscopy. The morphological changes occurring to the Er:YAG laser prepared dentin and the structural characteristics of the studied pulp-capping materials are demonstrated using scanograms. The border areas where good contact of materials and dentinal tubules is established are thoroughly studied. Good adaptation is seen in three-calcium silicate cement, followed by mineral trioxide aggregate and calcium hydroxide cement. The dentin surface, prepared with Er:YAG laser demonstrates a very good adaptation of the three tested pulp-capping materials.

  16. Viability of imaging structures inside human dentin using dental transillumination

    Science.gov (United States)

    Grandisoli, C. L.; Alves-de-Souza, F. D.; Costa, M. M.; Castro, L.; Ana, P. A.; Zezell, D. M.; Lins, E. C.

    2014-02-01

    Dental Transillumination (DT) is a technique for imaging internal structures of teeth by detecting infrared radiation transmitted throughout the specimens. It was successfully used to detect caries even considering dental enamel and dentin scatter infrared radiation strongly. Literature reports enamel's scattering coefficient is 10 to 30 times lower than dentin; this explain why DT is useful for imaging pathologies in dental enamel, but does not disable its using for imaging dental structures or pathologies inside the dentin. There was no conclusive data in the literature about the limitations of using DT to access biomedical information of dentin. The goal in this study was to present an application of DT to imaging internal structures of dentin. Slices of tooth were confectioned varying the thickness of groups from 0.5 mm up to 2,5 mm. For imaging a FPA InGaAs camera Xeva 1.7- 320 (900-1700 nm; Xenics, Inc., Belgium) and a 3W lamp-based broadband light source (Ocean Optics, Inc., USA) was used; bandpass optical filters at 1000+/-10 nm, 1100+/-10 nm, 1200+/-10 nm and 1300+/-50 nm spectral region were also applied to spectral selection. Images were captured for different camera exposure times and finally a computational processing was applied. The best results revealed the viability to imaging dent in tissue with thickness up to 2,5 mm without a filter (900-1700nm spectral range). After these results a pilot experiment of using DT to detect the pulp chamber of an incisive human tooth was made. New data showed the viability to imaging the pulp chamber of specimen.

  17. Sodium Thiosulfate for Recovery of Bond Strength to Dentin Treated with Sodium Hypochlorite.

    Science.gov (United States)

    Pimentel Corrêa, Ana Carolina; Cecchin, Doglas; de Almeida, José Flávio Affonso; Gomes, Brenda Paula Figueiredo de Almeida; Zaia, Alexandre Augusto; Ferraz, Caio Cezar Randi

    2016-02-01

    The aim of this study was to evaluate the efficacy of sodium thiosulfate (Na2S2O3) for restoring adhesion to pulp chamber dentin treated with sodium hypochlorite (NaOCl) and EDTA. Sixty-three crowns of bovine incisors were cut to expose the dentin pulp chamber. The specimens were polished and randomly distributed into 9 groups (n = 7) according to the following protocols used: 0.9% sodium chloride for 30 minutes (negative control), 5.25% NaOCl for 30 minutes, 17% EDTA for 3 minutes, and 5.25% NaOCl for 1 minute (positive control). The other groups, after treatments with NaOCl and EDTA, were immersed in 0.5% or 5% Na2S2O3 for 1, 5, and 10 minutes or just immersed in an inert solution for 10 minutes (0.9% sodium chloride). After drying the specimens, Scotchbond Multi-Purpose (3M ESPE, St Paul, MN) was applied to the pulp chamber dentin followed by Filtek Z250 composite (3M ESPE). Six rectangular slabs were obtained from each specimen, and the dentin/resin interface was tested by using a universal testing machine. The resulting data were submitted to 1-way analysis of variance and the Duncan test (P = .05). There was a significant decrease in bond strength regarding NaOCl and EDTA (P composite resin to NaOCl/EDTA-treated dentin, allowing adhesive restorations to be immediately applied after endodontic treatment. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Noninvasive Quantitative Evaluation of the Dentin Layer during Dental Procedures Using Optical Coherence Tomography

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    Cosmin Sinescu

    2015-01-01

    Full Text Available A routine cavity preparation of a tooth may lead to opening the pulp chamber. The present study evaluates quantitatively, in real time, for the first time to the best of our knowledge, the drilled cavities during dental procedures. An established noninvasive imaging technique, Optical Coherence Tomography (OCT, is used. The main scope is to prevent accidental openings of the dental pulp chamber. Six teeth with dental cavities have been used in this ex vivo study. The real time assessment of the distances between the bottom of the drilled cavities and the top of the pulp chamber was performed using an own assembled OCT system. The evaluation of the remaining dentin thickness (RDT allowed for the positioning of the drilling tools in the cavities in relation to the pulp horns. Estimations of the safe and of the critical RDT were made; for the latter, the opening of the pulp chamber becomes unavoidable. Also, by following the fractures that can occur when the extent of the decay is too large, the dentist can decide upon the right therapy to follow, endodontic or conventional filling. The study demonstrates the usefulness of OCT imaging in guiding such evaluations during dental procedures.

  19. Novel dentin phosphoprotein frameshift mutations in dentinogenesis imperfecta type II.

    Science.gov (United States)

    Lee, K-E; Kang, H-Y; Lee, S-K; Yoo, S-H; Lee, J-C; Hwang, Y-H; Nam, K H; Kim, J-S; Park, J-C; Kim, J-W

    2011-04-01

    The dentin sialophosphoprotein (DSPP) gene encodes the most abundant non-collagenous protein in tooth dentin and DSPP protein is cleaved into several segments including the highly phosphorylated dentin phosphoprotein (DPP). Mutations in the DSPP gene have been solely related to non-syndromic form of hereditary dentin defects. We recruited three Korean families with dentinogenesis imperfecta (DGI) type II and sequenced the exons and exon-intron boundaries of the DSPP gene based on the candidate gene approach. Direct sequencing of PCR products and allele-specific cloning of the highly repetitive exon 5 revealed novel single base pair (bp) deletional mutations (c.2688delT and c.3560delG) introducing hydrophobic amino acids in the hydrophilic repeat domain of the DPP coding region. All affected members of the three families showed exceptionally rapid pulp chambers obliteration, even before tooth eruption. Individuals with the c.3560delG mutation showed only mild, yellowish tooth discoloration, in contrast to the affected individuals from two families with c.2688delT mutation. We believe that these results will help us to understand the molecular pathogenesis of DGI type II as well as the normal process of dentin biomineralization.

  20. Temperature changes under demineralized dentin during polymerization of three resin-based restorative materials using QTH and LED units

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    Sayed-Mostafa Mousavinasab

    2014-08-01

    Full Text Available Objectives Light-curing of resin-based materials (RBMs increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs of three different RBMs using quartz tungsten halogen (QTH and light-emitting diode (LED units (LCUs. Materials and Methods Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12 during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey, a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE, and a giomer (Beautifil II, Shofu GmbH, was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. Results The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p 0.05. Conclusions Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

  1. Dentin diffusion of HEMA released from etch-and-rinse and self-etch bonding systems.

    Science.gov (United States)

    Rathke, Andreas; Alt, Andreas; Gambin, Nadin; Haller, Bernd

    2007-12-01

    The aim of this in vitro study was to determine the diffusion of 2-hydroxyethyl methacrylate (HEMA) released from different bonding systems (BS) through dentin. Occlusal cavities with a remaining dentin thickness (RDT) of 0.5 mm (n=90) and 0.25 mm (n=80), respectively, were prepared in dentin discs of non-carious human molars. Artificial pulp chambers were attached to the pulpal side of each dentin disc. Bonding systems were applied with (Clearfil SE Bond, OptiBond FL, OptiBond Solo Plus) or without (AdheSE, Adper Prompt L-Pop, Clearfil SE Bond, OptiBond FL, OptiBond Solo Plus Self Etch, Xeno III) prior phosphoric acid etching. HEMA was detected by gas chromatography/mass spectrometry (n=10 per BS and RDT). The highest mean HEMA concentration was found in the 0.25 mm RDT group treated with OptiBond FL (13.3 microg) and the lowest mean HEMA concentration was detected in the 0.5 mm RDT group treated with AdheSE (0.5 microg). At 0.25 mm RDT the quantities of HEMA recovered in the artificial pulp chambers were significantly higher than at 0.5 mm RDT, except for Clearfil SE Bond. Etching with phosphoric acid increased the detected HEMA quantities compared with self-etch BS. In deep cavity preparations, etching with phosphoric acid should be avoided in favor of the use of self-etch BS.

  2. Hereditary dentine disorders: dentinogenesis imperfecta and dentine dysplasia

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    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

  3. Hereditary dentine disorders: dentinogenesis imperfecta and dentine dysplasia.

    Science.gov (United States)

    Barron, Martin J; McDonnell, Sinead T; Mackie, Iain; Dixon, Michael J

    2008-11-20

    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 number of options including

  4. Effect of biomaterials on angiogenesis during vital pulp therapy

    National Research Council Canada - National Science Library

    SAGHIRI, Mohammad Ali; ASATOURIAN, Armen; GARCIA-GODOY, Franklin; SHEIBANI, Nader

    2016-01-01

    This review intended to provide an overview of the effects of dental materials, used in dentin-pulp complex and dental pulp regeneration, on angiogenesis processes during regenerative endodontic procedures...

  5. Infection and Pulp Regeneration

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    Sahng G. Kim

    2016-03-01

    Full Text Available The regeneration of the pulp-dentin complex has been a great challenge to both scientists and clinicians. Previous work has shown that the presence of prior infection may influence the characteristics of tissues formed in the root canal space after regenerative endodontic treatment. The formation of ectopic tissues such as periodontal ligament, bone, and cementum has been observed in the root canal space of immature necrotic teeth with apical periodontitis, while the regeneration of dentin and pulp has been identified in previously non-infected teeth. The current regenerative endodontic therapy utilizes disinfection protocols, which heavily rely on chemical irrigation using conventional disinfectants. From a microbiological point of view, the current protocols may not allow a sufficiently clean root canal microenvironment, which is critical for dentin and pulp regeneration. In this article, the significance of root canal disinfection in regenerating the pulp-dentin complex, the limitations of the current regenerative endodontic disinfection protocols, and advanced disinfection techniques designed to reduce the microorganisms and biofilms in chronic infection are discussed.

  6. Signaling Molecules and Pulp Regeneration.

    Science.gov (United States)

    Schmalz, Gottfried; Widbiller, Matthias; Galler, Kerstin M

    2017-09-01

    Signaling molecules play an essential role in tissue engineering because they regulate regenerative processes. Evidence exists from animal studies that single molecules such as members of the transforming growth factor beta superfamily and factors that induce the growth of blood vessels (vascular endothelial growth factor), nerves (brain-derived neurotrophic factor), or fibroblasts (fibroblast growth factor) may induce reparative dentin formation. Mainly the formation of atubular dentin (osteodentin) has been described after the application of single molecules or combinations of recombinant growth factors on healthy exposed pulps or in pulp regeneration. Generally, such preparations have not received regulatory approval on the market so far. Only the use of granulocyte colony-stimulating factors together with cell transplantation is presently tested clinically. Besides approaches with only 1 or few combined molecules, the exploitation of tissue-derived growth factors depicts a third promising way in dental pulp tissue engineering. Preparations such as platelet-rich plasma or platelet-rich fibrin provide a multitude of endogenous signaling molecules, and special regulatory approval for the market does not seem necessary. Furthermore, dentin is a perfect reservoir of signaling molecules that can be mobilized by treatment with demineralizing agents such as EDTA. This conditions the dentin surface and allows for contact differentiation of pulp stem cells into odontoblastlike cells, protects dentin from resorption, and enhances cell growth as well as attachment to dentin. By ultrasonic activation, signaling molecules can be further released from EDTA pretreated dentin into saline, thus avoiding cytotoxic EDTA in the final preparation. The use of dentin-derived growth factors offers a number of advantages because they are locally available and presumably are most fit to induce signaling processes in dental pulp. However, better characterization and standardization of the

  7. Dentin conditioning codetermines cell fate in regenerative endodontics.

    Science.gov (United States)

    Galler, Kerstin M; D'Souza, Rena N; Federlin, Marianne; Cavender, Adriana C; Hartgerink, Jeffrey D; Hecker, Stephanie; Schmalz, Gottfried

    2011-11-01

    Recent successes in dental pulp engineering indicate that regenerative treatment strategies in endodontics are feasible. Clinically, revascularization procedures render completion of root formation in immature teeth. The generation of a pulp-like tissue after seeding of dental pulp stem cells into dentin discs or cylinders and transplantation in vivo is possible. In this experimental setup, which mimics the situation in the root canal, the pretreatment of dentin might influence cellular behavior at the cell-dentin interface. Thus, the objective of this study was to investigate whether dentin conditioning can determine cell fate. Dental pulp stem cells (DPSCs) were seeded into a growth factor-laden peptide hydrogel, transferred into dentin cylinders, and transplanted subcutaneously into immunocompromised mice. Before cell seeding, dentin cylinders were either pretreated with sodium hypochloride (NaOCl) or conditioned with EDTA. The constructs were explanted after 6 weeks and subjected to histological and immunohistochemical analysis. In dentin treated with NaOCl, resorption lacunae were found at the cell-dentin interface created by multinucleated cells with clastic activity. After conditioning with EDTA, DPSCs adjacent to the dentin formed an intimate association with the surface, differentiated into odontoblasts-like cells that expressed dentin sialoprotein, and extended cellular processes into the dentinal tubules. A vascularized soft connective tissue similar to dental pulp was observed inside the dentin cylinder. Dentin conditioning considerably influences DPSC fate when seeded in close proximity to dentin. This information might be critical for optimized strategic planning for future regenerative endodontic treatment. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Gambaran densitas kamar pulpa gigi sulung menggunakan cone beam CT-3D (Description of pulp chamber density in deciduous teeth using cone beam CT-3D

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    Herdiyati Y

    2013-06-01

    Full Text Available Background: Dental caries is the most common chronic diseases. Detection of caries is needed, especially on the deciduous teeth. An examination such as radiological examination is essential. The radiographic figures distinguish radiolucent of the crown. Digital radiography cone beam computed tomography (CBCT is able to show a more detailed picture. Purpose: This study was aimed to get value of the density of pulp chamber of caries and non caries deciduous teeth using CBCT radiographs. Methods: The study was conducted by using simple descriptive. The samples were all the data CBCT of pediatric patients aged 7-10 years who visited the Dental Hospital of the Faculty of Dentistry, University of Padjadjaran. The samples were teeth with single and double root. Results: The results showed that the value of the normal pulp density is 422.56 Hu, while the condition of caries decreased becomes -77.89 Hu. Conclusion: The tooth with caries showed a lower density than the non caries/tooth.Latar belakang: Karies gigi merupakan penyakit kronis yang sering terjadi. Deteksi terhadap karies sangat diperlukan terutama pada gigi decidius. Pemeriksaan penunjang berupa pemeriksaan radiologis sangat diperlukan. Secara umum gambaran radiografi dapat membedakan karies berupa gambaran radiolusent pada mahkota. Radiografi digital cone beam computed tomografi (CBCT, merupakan jenis radiografi yang mampu memperlihatkan gambaran yang lebih detail. Tujuan: Penelitian ini bertujuan mendapatkan nilai densitas kamar pulpa gigi sulung yang karies dan non karies menggunakan radiografi CBCT. Metode: Penelitian dilakukan dengan metode simple deskriptif. Sampel penelitian adalah semua data CBCT dari pasien anak berusia 7 - 10 tahun yang berkunjung ke RSGM Fakultas Kedokteran Gigi Universitas Padjadjaran. Gigi yang dianalisa meliputi gigi berakar tunggal dan berakar ganda. Hasil: Hasil penelitian menunjukkan bahwa nilai densitas pulpa normal adalah 422,56 Hu, sedangkan pada kondisi

  9. Dentinal Dysplasia Type I: A Case Report with a 6-Year Followup

    Directory of Open Access Journals (Sweden)

    Sezin Ozer

    2013-01-01

    Full Text Available Introduction. Dentin dysplasia is a rare disturbance of dentin formation characterized by normal enamel but atypical dentin formation with abnormal pulpal morphology that is inherited as an autosomal pulpal morphology. Case Presentation. A 7-year-old female who had problems in chewing function was referred to Oral and Maxillofacial Surgery Department at the Faculty of Dentistry in Ondokuz Mayıs University. In the radiographic examination, it was determined that some of the unerupted permanent teeth of the patient had short, blunted, and malformed roots with obliterated pulp chambers, although the bone below the teeth showed well-defined margins. This unusual case of generalized short roots presents a case demonstrating both classic and atypical features of dentinal dysplasia type I (DDI in the mixed and permanent dentitions. Conclusion. There are still many issues in the diagnosis and management of patients with dentin dysplasia. Early diagnosis, clinical and radiographic findings, as well as treatment of this condition and the initiation of effective preventive strategies may help prevent or delay loss of dentition.

  10. Relationship between laser fluorescence and bacterial invasion in arrested dentinal carious lesions.

    Science.gov (United States)

    Iwami, Yukiteru; Yamamoto, Hiroko; Hayashi, Mikako; Ebisu, Shigeyuki

    2011-07-01

    This study investigated the relationship between caries assessment using a laser fluorescence device (DIAGNOdent), and bacterial invasion in arrested carious dentin detected by polymerase chain reaction (PCR). The ten extracted human molars used in this study had black or dark brown, hard occlusal carious lesions, and were found to be only weakly stained or unstained with a caries detector dye of 1% acid red in propylene glycol. In those extracted human molars, dentin was removed in the direction of the pulp chamber at 150-μm intervals. During each removal (104 sections in total), the dentin surface was assessed with DIAGNOdent, and a dentinal tissue sample was taken with a round bur. Bacterial DNA of each tissue sample was examined using PCR and primers based on the nucleotide sequence of a conserved region of bacterial 16S rDNA. Rates of bacterial detection increased as the DIAGNOdent values increased. When the DIAGNOdent values were DIAGNOdent values was 0.87. These results indicate that the DIAGNOdent values of arrested dentinal carious lesion were closely related to the rates of bacterial detection.

  11. Dentinal Dysplasia Type I: A Case Report with a 6-Year Followup

    Science.gov (United States)

    Ozer, Sezin; Ozden, Bora; Otan Ozden, Feyza; Gunduz, Kaan

    2013-01-01

    Introduction. Dentin dysplasia is a rare disturbance of dentin formation characterized by normal enamel but atypical dentin formation with abnormal pulpal morphology that is inherited as an autosomal pulpal morphology. Case Presentation. A 7-year-old female who had problems in chewing function was referred to Oral and Maxillofacial Surgery Department at the Faculty of Dentistry in Ondokuz Mayıs University. In the radiographic examination, it was determined that some of the unerupted permanent teeth of the patient had short, blunted, and malformed roots with obliterated pulp chambers, although the bone below the teeth showed well-defined margins. This unusual case of generalized short roots presents a case demonstrating both classic and atypical features of dentinal dysplasia type I (DDI) in the mixed and permanent dentitions. Conclusion. There are still many issues in the diagnosis and management of patients with dentin dysplasia. Early diagnosis, clinical and radiographic findings, as well as treatment of this condition and the initiation of effective preventive strategies may help prevent or delay loss of dentition. PMID:23762649

  12. Pulp response to Streptococcus mutans.

    Science.gov (United States)

    Paterson, R C; Pountney, S K

    1987-09-01

    The maxillary molar pulps of germ-free rats were mechanically exposed, and suspensions of a strain of freshly grown Streptococcus mutans were applied to the pulp wounds. The pulps were left open to the oral environment, and the animals were maintained in the isolator until they were killed in groups after 2, 7, and 28 days. After 2 days there was little evidence of any pulp response. In the 7-day group early pulp necrosis was present. No evidence of inflammatory infiltration was detected in either the 2- or 7-day animals. After 28 days there was extensive pulp necrosis in many specimens. Dentine bridges were present in fewer than one fourth of the teeth.

  13. Effect of white mineral trioxide aggregate compared with biomimetic carbonated apatite on dentine bridge formation and inflammatory response in a dental pulp model.

    Science.gov (United States)

    Danesh, F; Vahid, A; Jahanbani, J; Mashhadiabbas, F; Arman, E

    2012-01-01

      To evaluate the effects of apatite precipitation on the biocompatibility and hard tissue induction properties of white mineral trioxide aggregate (WMTA) in a dental pulp model.   Pulp exposures were created on the axial walls of 32 sound canine teeth of eight dogs. Four additional sound teeth served as controls. The pulps were capped either with WMTA or apatite derivatives [biomimetic carbonated apatite (BCAp)] in the interaction of WMTA with a synthetic tissue fluid and restored with zinc oxide-eugenol cement. After 7 and 70 days, the animals were killed, and the histological specimens taken from the teeth were stained with haematoxylin and eosin for histomorphological evaluation. The Brown and Brenn technique was employed to stain bacteria. The data were subjected to nonparametric Kruskall-Wallis analysis and Mann-Whitney U_tests.   Biomimetic carbonated apatite did not induce hard tissue bridge formation. WMTA performed significantly better than BCAp in this respect at both periods (P 0.05).   White mineral trioxide aggregate induced hard tissue formation via a mechanism other than that postulated via apatite formation. © 2011 International Endodontic Journal.

  14. Effect of EDTA on TGF-β1 released from the dentin matrix and its influence on dental pulp stem cell migration.

    Science.gov (United States)

    Gonçalves, Lidiany Freitas; Fernandes, Ana Paula; Cosme-Silva, Leopoldo; Colombo, Fabio Antonio; Martins, Natália Silva; Oliveira, Thais Marchini; Araujo, Tomaz Henrique; Sakai, Vivien Thiemy

    2016-12-22

    Bioactive molecules stored in dentin, such as transforming growth factor beta1 (TGF-b1), may be involved in the signaling events related to dental tissue repair. The authors conducted an in vitro evaluation of the amount of TGF-b1 released from dentin slices after treatment with 10% ethylenediaminetetraacetic acid (EDTA), 2.5% sodium hypochlorite (NaOCl) or phosphate-buffered saline (PBS), and the effect of this growth factor on stem cell migration from human exfoliated deciduous teeth (SHED). Sixty 1-mm-thick tooth slices were prepared with or without the predentin layer, and treated with either 10% EDTA for 1 minute, 2.5% NaOCl for 5 days or kept in PBS. Tooth slice conditioned media were prepared and used for TGF-b1 ELISA and migration assays. Culture medium with different concentrations of recombinant human TGF-b1 (0.5, 1.0, 5.0 or 10.0 ng/mL) was also tested by migration assay. The data were evaluated by ANOVA and Tukey's test. Optical density values corresponding to media conditioned by tooth slices either containing or not containing the predentin layer and treated with 10% EDTA were statistically greater than the other groups and close to 1 ng/mL. Increased rates of migration toward media conditioned by tooth slices containing the predentin layer and treated with PBS, 10% EDTA or 2.5% NaOCl were observed. Recombinant human TGF-b1 also stimulated migration of SHED, irrespective of the concentration used. EDTA may be considered an effective extractant of TGF-b1 from the dentin matrix. However, it does not impact SHED migration, suggesting that other components may account for the cell migration.

  15. Growth Factor Liberation and DPSC Response Following Dentine Conditioning.

    Science.gov (United States)

    Sadaghiani, L; Gleeson, H B; Youde, S; Waddington, R J; Lynch, C D; Sloan, A J

    2016-10-01

    Liberation of the sequestrated bioactive molecules from dentine by the action of applied dental materials has been proposed as an important mechanism in inducing a dentinogenic response in teeth with viable pulps. Although adhesive restorations and dentine-bonding procedures are routinely practiced, clinical protocols to improve pulp protection and dentine regeneration are not currently driven by biological knowledge. This study investigated the effect of dentine (powder and slice) conditioning by etchants/conditioners relevant to adhesive restorative systems on growth factor solubilization and odontoblast-like cell differentiation of human dental pulp progenitor cells (DPSCs). The agents included ethylenediaminetetraacetic acid (EDTA; 10%, pH 7.2), phosphoric acid (37%, pH EDTA, phosphoric acid, and citric acid from powdered dentine. The dentine matrix extracts were shown to be bioactive, capable of stimulating odontogenic/osteogenic differentiation as observed by gene expression and phenotypic changes in DPSCs cultured in monolayer on plastic. Polyacrylic acid failed to solubilize proteins from powdered dentine and was therefore considered ineffective in triggering a growth factor-mediated response in cells. The study went on to investigate the effect of conditioning dentine slices on growth factor liberation and DPSC behavior. Conditioning by EDTA, phosphoric acid, and citric acid exposed growth factors on dentine and triggered an upregulation in genes associated with mineralized differentiation, osteopontin, and alkaline phosphatase in DPSCs cultured on dentine. The cells demonstrated odontoblast-like appearances with elongated bodies and long extracellular processes extending on dentine surface. However, phosphoric acid-treated dentine appeared strikingly less populated with cells, suggesting a detrimental impact on cell attachment and growth when conditioning by this agent. These findings take crucial steps in informing clinical practice on dentine

  16. Effectiveness and biological compatibility of different generations of dentin adhesives.

    Science.gov (United States)

    da Silva, João M F; Rodrigues, José R; Camargo, Carlos H R; Fernandes, Virgilio Vilas Boas; Hiller, Karl-Anton; Schweikl, Helmut; Schmalz, Gottfried

    2014-01-01

    Besides possessing good mechanical properties, dental materials should present a good biological behavior and should not injure the involved tissues. Bond strength and biocompatibility are both highly significant properties of dentin adhesives. For that matter, these properties of four generations of adhesive systems (Multi-Purpose/Single Bond/SE Plus/Easy Bond) were evaluated. Eighty bovine teeth had their dentin exposed (500- and 200-μm thickness). Adhesive was applied on the dentin layer of each specimen. Following that, the microshearing test was performed for all samples. A dentin barrier test was used for the cytotoxicity evaluation. Cell cultures (SV3NeoB) were collected from testing materials by means of 200- or 500-μm-thick dentin slices and placed in a cell culture perfusion chamber. Cell viability was measured 24 h post-exposition by means of a photometrical test (MTT test). The best bonding performance was shown by the single-step adhesive Easy Bond (21 MPa, 200 μm; 27 MPa, 500 μm) followed by Single Bond (15.6 MPa, 200 μm; 23.4 MPa, 500 μm), SE Plus (18.2 MPa, 200 μm; 20 MPa, 500 μm), and Multi-Purpose (15.2 MPa, 200 μm; 17.9 MPa, 500 μm). Regarding the cytotoxicity, Multi-Purpose slightly reduced the cell viability to 92% (200 μm)/93% (500 μm). Single Bond was reasonably cytotoxic, reducing cell viability to 71% (200 μm)/64% (500 μm). The self-etching adhesive Scotchbond SE decreased cell viability to 85% (200 μm)/71% (500 μm). Conversely, Easy Bond did not reduce cell viability in this test, regardless of the dentin thickness. Results showed that the one-step system had the best bond strength performance and was the least toxic to pulp cells. In multiple-step systems, a correct bonding technique must be done, and a pulp capping strategy is necessary for achieving good performance in both properties. The study showed a promising system (one-step self-etching), referring to it as a good alternative for specific cases, mainly due to its

  17. Iloprost induces tertiary dentin formation.

    Science.gov (United States)

    Limjeerajarus, Chalida Nakalekha; Chanarattanubol, Thichaporn; Trongkij, Panruethai; Rujiwanichkul, Mirantee; Pavasant, Prasit

    2014-11-01

    Prostacyclin (PGI2), a member of the prostaglandin family, can promote angiogenesis and cell proliferation. In this study, the effect of the application of a PGI2 analog (iloprost) on dentin repair was examined in vitro and in vivo. Iloprost significantly stimulated the expression of vascular endothelial growth factor and osteo-/odontogenic marker messenger RNA in human dental pulp cells (HDPCs) under osteoinductive conditions in vitro. In addition, iloprost enhanced HDPC alkaline phosphatase enzymatic activity and mineral deposition. An in vivo study was performed using a rat molar mechanical pulp exposure model. After 30 days, histologic analysis revealed that there was a dramatic tertiary dentin formation in the iloprost-treated group compared with the calcium hydroxide and the untreated control groups. Furthermore, vascular endothelial growth factor protein expression in dental pulp tissue was increased in the iloprost-treated group as determined by immunohistochemical staining. Taken together, the present study, for the first time, shows that iloprost induces the expression of osteo-/odontogenic markers in vitro and promotes angiogenic factor expression and enhances tertiary dentin formation in vivo. This implies the potential clinical usefulness of iloprost in vital pulp therapy. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. HISTOLOGICAL ANALYSIS OF IN VITRO REGENERATION OF HUMAN DENTAL PULP COMPLEX WITH AUTOLOGOUS TISSULAR ENGINEERING

    OpenAIRE

    Romero Márquez, Ricardo Manuel; Docente Colaborador del Departamento de Ciencias Básicas Estomatológicas, Curso de Patología General y del Sistema Estomatognático. Facultad de Odontología. UNMSM.

    2014-01-01

    A long time ago, dental pulp-complex regeneration was our main objective in radicular reparation which could guarantee all appropiate growth of healthy and functional tissue. The present study is about a histological assay of a new dentinal-pulp complex formation using platelet rich plasm, pulpar tissue and fibrina, all autolougus, as components of dental pulp tissular engineering treatment. Qualitative and quantitative assays about the dentin pulp-complex regeneration grade on experimental a...

  19. Two-photon laser confocal microscopy of micropermeability of resin-dentin bonds made with water or ethanol wet bonding.

    Science.gov (United States)

    Sauro, Salvatore; Watson, Timothy F; Mannocci, Francesco; Miyake, Katsuya; Huffman, Bradford P; Tay, Franklin R; Pashley, David H

    2009-07-01

    This study evaluated the micropermeability of six etch-and-rinse adhesives bonded to dentin. There were two principal groups: wet bonding with water or wet bonding with absolute ethyl alcohol. After bonding and the creation of composite build-ups, the pulp chambers were filled with 0.1% lucifer yellow. The contents of the pulp chamber were kept under 20 cm H(2)O pressure to simulate pulpal pressure for 3 h. The specimens were vertically sectioned into multiple 0.5-mm thick slabs that were polished and then examined using a two-photon confocal laser scanning microscope (TPCLSM). The results showed that specimens bonded with adhesives using the water wet-bonding condition all showed tracer taken up uniformly by the hybrid layer. This uptake of fluorescent tracer into the hybrid layer was quantified by computer software. The most hydrophobic experimental resins showed the highest fluorescent tracer uptake (ca. 1800 +/- 160 arbitrary fluorescent units/std. surface area). The most hydrophilic experimental resins showed the lowest tracer uptake into water-saturated hybrid layers. When ethanol wet-bonding was used, significantly less fluorescent tracer was seen in hybrid layers. The most hydrophilic experimental resins and Single Bond Plus showed little micropermeability. Clearly, ethanol wet-bonding seals dentin significantly better than water-wet dentin regardless of the adhesive in etch-and-rinse systems.

  20. Respons Pulp Gigi Tikus terhadap Propolis Sebagai Bahan Kaping Pulpa Langsung

    OpenAIRE

    Ardo Sabir, Dr.drg. M.Kes

    2016-01-01

    The present result suggest that direct pulp capping with EEP in rats may delay dental pulp inflammatory process and fail to stimulate reparative dentin. The aim of the present study was to assess the response of rat dental pulp to direct pulp caping with ethanol extracts of propolis (EEP)

  1. Is pulpotomy obsolete? A clinical study on the success rates of indirect pulp capping and pulpotomy in the treatment of deep dentinal caries in primary second molars

    Directory of Open Access Journals (Sweden)

    K B Vidya

    2015-01-01

    Full Text Available Background and Objectives: Traditionally, there are two treatment modalities for vital primary teeth with deep carious lesion, which include indirect pulp therapy (IPT and pulpotomy. Enormous research and review in vital pulp therapy gave rise to a question, if primary tooth pulpotomy is obsolete, and should IPT replace pulpotomy? IPT has shown higher long-term success rates than any pulpotomy procedures other than mineral trioxide aggregate (MTA. Hence, the objectives of this study were to evaluate the success rates of IPT using calcium hydroxide and MTA pulpotomy clinically and radiographically. Materials and Methods: Eighty primary second molars were selected and randomly divided into two therapeutic groups of 40 each. Group 1 were treated with IPT using calcium hydroxide paste and Group 2 were treated with conventional pulpotomy using MTA paste followed by stainless steel crown. Follow-up evaluation was done at an interval of 6 weeks, 3 months, and 6 months. Results: The follow-up evaluation revealed 100% clinical success in teeth treated with MTA pulpotomy and one radiographic failure of internal resorption detected at 3 months. There was 100% clinical and radiographic success with teeth treated with IPT. Though there was one radiographic failure with MTA pulpotomy, it was not statistically significant (P > 0.05. Conclusion: Indications being the same for both the procedures why not opt for IPT which offers several advantages over pulpotomy like fewer potential side effects, non-invasive, decreased chair time, child cooperation, and cost-effectiveness.

  2. The microbial challenge to pulp regeneration.

    Science.gov (United States)

    Fouad, A F

    2011-07-01

    Pulp regeneration is considered in cases where the dental pulp has been destroyed because of microbial irritation. Diverse oral and food-borne micro-organisms are able to invade the pulp space, form biofilm on canal walls, and infiltrate dentinal tubules. Prior to pulp regeneration procedures, the pulp space and dentinal walls need to be sufficiently disinfected to allow for and promote regeneration. The necessary level of disinfection is likely higher than that accepted for traditional endodontic therapy, because in traditional techniques the mere lowering of bacterial loads and prevention of bacterial access to periapical tissues is conducive to healing. Moreover, several of the non-specific antimicrobials used in traditional endodontic therapy may cause significant changes in remaining dentin that interfere with its inherent potential to mediate regeneration. Non-specific antimicrobials also suppress all microbial taxa, which may allow residual virulent micro-organisms to preferentially repopulate the pulp space. Therefore, it is important for endodontic pathogens to be studied by molecular methods that allow for a broad depth of coverage. It is then essential to determine the most effective protocols to disinfect the pulp space, with minimal disruption of remaining dentin. These protocols include the topical use of effective antibiotics, including newer agents that have demonstrated efficacy against endodontic pathogens.

  3. Comparison of temperature rise in pulp chamber during polymerization of materials used for direct fabrication of provisional restorations: An in-vitro study

    Science.gov (United States)

    Khajuria, Rajat R.; Madan, Ravi; Agarwal, Swatantra; Gupta, Reecha; Vadavadgi, Sunil V.; Sharma, Vikas

    2015-01-01

    Objective: The purpose is to compare temperature rise in the pulp chamber during fabrication of provisional crowns using different materials and on different types of teeth using direct technique. Materials and Methods: An extracted, sound, caries free maxillary central incisor and a mandibular molar were selected for the study and crown preparations of all ceramic and all metal were done on central incisor and mandibular molar, respectively. Materials tested were DPI tooth molding self-curing material and protemp-4. Addition silicone putty was used as a matrix and 80 provisional crowns were fabricated, of which 40 were on central incisor and 40 on mandibular molar. Depending on the type of material used, they were further divided into two subgroups: Each comprising 20 provisional crowns. Temperature readings were recorded using K type of thermocouple with 0.1°C precision digital thermometer. Statistical Analysis Used: Analysis of variance, Tukey honest significant difference and Kruskall–Wallis H-test. Results: Statistically significant difference exists between two materials tested on the basis of peak temperature achieved and time taken by a particular material to reach peak temperature. Peak temperature achieved was highest for provisional crowns with DPI tooth molding self-curing material on maxillary central incisor (40.39 + 0.46), followed by DPI tooth molding self-curing material on mandibular molar (40.03 + 0.32), protemp-4 on maxillary central incisor (39.46 + 0.26) and least with protemp-4 on mandibular molar (39.09 + 0.33). The time taken to reach peak temperature was almost double in DPI tooth molding self-curing material (5 min) than in protemp-4. Conclusion: Polymethyl methacrylate resin produced higher intra-pulpal rise when compared to newer generation bis-acrylic composite. PMID:26038649

  4. DENTAL PULP TISSUE ENGINEERING

    Science.gov (United States)

    Demarco, FF; Conde, MCM; Cavalcanti, B; Casagrande, L; Sakai, V; Nör, JE

    2013-01-01

    Dental pulp is a highly specialized mesenchymal tissue, which have a restrict regeneration capacity due to anatomical arrangement and post-mitotic nature of odontoblastic cells. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial material cause loss of a significant amount of dentin leaving as life-lasting sequelae a non-vital and weakened tooth. However, regenerative endodontics is an emerging field of modern tissue engineering that demonstrated promising results using stem cells associated with scaffolds and responsive molecules. Thereby, this article will review the most recent endeavors to regenerate pulp tissue based on tissue engineering principles and providing insightful information to readers about the different aspects enrolled in tissue engineering. Here, we speculate that the search for the ideal combination of cells, scaffolds, and morphogenic factors for dental pulp tissue engineering may be extended over future years and result in significant advances in other areas of dental and craniofacial research. The finds collected in our review showed that we are now at a stage in which engineering a complex tissue, such as the dental pulp, is no longer an unachievable and the next decade will certainly be an exciting time for dental and craniofacial research. PMID:21519641

  5. A Histopathological Study of Direct Pulp Capping with Adhesive Resins

    Directory of Open Access Journals (Sweden)

    J. Salhenejad

    2004-12-01

    Full Text Available Statement of Problem: Recently, it has been proposed that different adhesive materials can be used for direct pulp capping. Previous studies have demonstrated that multi steps dentin adhesives could form reparative dentin similar to calcium hydroxide (CH.Purpose: The aim of this study was to evaluate the histological pulp response of ninety mechanically exposed cat pulps to two adhesive resins (Scotch Bond MP and Single Bond 3M were compared with a calcium hydroxide cement (Dycal, Dentsply.Materials and Methods : Class V facial cavities with similar pulpal exposures were prepared in canines. In the experimental groups phosphoric acid was used to etch the enamel and dentin and pulp exposure, and after it dentin adhesives was applied. The exposure point of the control group was capped with Dycal then the remainder of the cavities was etched and a dentin adhesive (single bond was applied. All of the cavities were restored with a composite resin (Z 100 in usual manner. The animals were scarified after 7, 30 and 60 days (n=30, and the pulp evaluated histologically, statistical analysis was carried out with Kruskal- Wallis test (a=0.05.Results: The data showed that most of the cases had mild inflammation of pulp tissue.There was no significant difference in inflammatory reaction of pulp by Dycal and two adhesive systems, severe inflammatory reaction of pulp was observed only in most of the 30- day Single Bond group. Soft tissue organization of dentin bridge was less than ScotchBond and Dycal groups, the differentiation of dentin bridge was less than Scotch Bond group after 7 days.Conclusion: Slight inflammatory cell infiltration was the main reaction of exposed pulp when two commercially available adhesive resins were placed directly on the exposed pulp.There was no significant difference in inflammatory reaction of pulp between Dycal and two adhesive systems after 7 days and 60 days. After 7 days most of the specimens showed an amount of predentin

  6. Viable bacteria in root dentinal tubules of teeth with apical periodontitis

    NARCIS (Netherlands)

    Peters, LB; Wesselink, P.R.; Buijs, JF; van Winkelhoff, AJ

    2001-01-01

    Two sets of teeth with apical periodontitis were collected at different geographic locations to study the identity of bacteria left in the root dentinal tubules. Root dentin of 20 of these teeth was cultured from three locations between pulp and cementum (A, B, and C). In addition dentin from eight

  7. Morphological aspects and physical properties of enamel and dentine of Sus domesticus: A tooth model in laboratory research.

    Science.gov (United States)

    Fagundes, Nathalia Carolina Fernandes; Cardoso, Miquéias André Gomes; Miranda, Mayara Sabrina Luz; Silva, Raira de Brito; Teixeira, Francisco Bruno; Nogueira, Bárbara Catarina Lima; Nogueira, Brenna Magdalena Lima; de Melo, Sara Elisama Silva; da Costa, Natacha Malu Miranda; Lima, Rafael Rodrigues

    2015-11-01

    This study aims to describe and analyze morphological and physical properties of deciduous teeth of Sus domesticus. Ultrastructural analysis, mineral composition and microhardness of enamel and dentine tissues were performed on 10 skulls of S. domesticus. External anatomic characteristics and the internal anatomy of the teeth were also described. Data regarding microhardness and ultrastructural analysis were subjected to statistical tests. For ultrastructural analysis, we used the analysis of variance (ANOVA) with Tukey's post hoc (p≤0.05) test. In the analysis of microhardness, the difference between the enamel and dentine tissues was analyzed by a Student's t test. Values were expressed as mean with standard error. The results of ultrastructural analysis showed the presence of an enamel prism pattern. A dentinal tubule pattern was also observed, with a larger diameter in the pulp chamber and the cervical third, in comparison to middle and apical thirds. We observed an average microhardness of 259.2kgf/mm(2) for enamel and 55.17kgf/mm(2) for dentine. In porcine enamel and dentine, the chemical elements Ca and P showed the highest concentration. The analysis of internal anatomy revealed the presence of a simple root canal system and the occurrence of main canals in the roots. The observed features are compatible with the functional demand of these animals, following a pattern very similar to that seen in other groups of mammals, which can encourage the development of research using dental elements from the pig as a substitute for human teeth in laboratory research.

  8. External Dentin Stimulation Induces ATP Release in Human Teeth.

    Science.gov (United States)

    Liu, X; Wang, C; Fujita, T; Malmstrom, H S; Nedergaard, M; Ren, Y F; Dirksen, R T

    2015-09-01

    ATP is involved in neurosensory processing, including nociceptive transduction. Thus, ATP signaling may participate in dentin hypersensitivity and dental pain. In this study, we investigated whether pannexins, which can form mechanosensitive ATP-permeable channels, are present in human dental pulp. We also assessed the existence and functional activity of ecto-ATPase for extracellular ATP degradation. We further tested if ATP is released from dental pulp upon dentin mechanical or thermal stimulation that induces dentin hypersensitivity and dental pain and if pannexin or pannexin/gap junction channel blockers reduce stimulation-dependent ATP release. Using immunofluorescence staining, we demonstrated immunoreactivity of pannexin 1 and 2 in odontoblasts and their processes extending into the dentin tubules. Using enzymatic histochemistry staining, we also demonstrated functional ecto-ATPase activity within the odontoblast layer, subodontoblast layer, dental pulp nerve bundles, and blood vessels. Using an ATP bioluminescence assay, we found that mechanical or cold stimulation to the exposed dentin induced ATP release in an in vitro human tooth perfusion model. We further demonstrated that blocking pannexin/gap junction channels with probenecid or carbenoxolone significantly reduced external dentin stimulation-induced ATP release. Our results provide evidence for the existence of functional machinery required for ATP release and degradation in human dental pulp and that pannexin channels are involved in external dentin stimulation-induced ATP release. These findings support a plausible role for ATP signaling in dentin hypersensitivity and dental pain.

  9. Quantification of peroxide ion passage in dentin, enamel, and cementum after internal bleaching with hydrogen peroxide.

    Science.gov (United States)

    Palo, R M; Bonetti-Filho, I; Valera, M C; Camargo, C H R; Camargo, Sea; Moura-Netto, C; Pameijer, C

    2012-01-01

    The aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. Fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (CEJ), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. The external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, exposed dentin, or cementum surface of the tooth. The teeth were divided into three experimental groups according to exposed areas close to the CEJ and into two control groups (n=10/group), as follows: GE, enamel exposure area; GC, cementum exposed area; GD, dentin exposed area; Negative control, no presence of internal bleaching agent and uncoated surface; and Positive control, pulp chamber filled with bleaching agent and external surface totally coated with nail varnish. The pulp chamber was filled with 35% hydrogen peroxide (Opalescence Endo, Ultradent). Each sample was placed inside of individual flasks with 1000 μL of acetate buffer solution, 2 M (pH 4.5). After seven days, the buffer solution was transferred to a glass tube, in which 100 μL of leuco-crystal violet and 50 μL of horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to Kruskal-Wallis and Dunn-Bonferroni tests (α=0.05). All experimental groups presented passage of peroxide to the external surface that was statistically different from that observed in the control groups. It was verified that the passage of peroxide was higher in GD than in GE (pperoxide passage than did GD and GE (pperoxide placed into the pulp chamber passed through the dental hard tissues, reaching the external surface and the periodontal tissue. The cementum surface

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

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Renata M. [Department of Dental Materials and Pronsthodontics at Sao Jose dos Campos Dental Shool, Sao Paulo State University (UNESP), Sao Jose dos Campos, Sao Paulo 12245-820 (Brazil); Rahbar, Nima, E-mail: nrahbar@umassd.edu [Department of Civil and Environmental Engineering, University of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02720 (United States); Soboyejo, Wole [Department of Mechanical and Aerospace Engineering, Princeton Institute of Science and Technology of Materials (PRISM), Princeton University, Princeton, New Jersey 08544 (United States)

    2011-05-10

    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 {approx} 1.5 to 3.2 J/m{sup 2} when the loading angle increases from {approx} 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.

  11. Dentin Topographic Features following Chemomechanical Caries Removal in Primary Teeth.

    Science.gov (United States)

    Kotb, R M; Elkateb, M A; Ahmed, A M; Kawana, K Y; El Meligy, O A

    Study the topographic features of dentin after caries removal with a chemomechanical agent (Papacarie) compared with the conventional drilling method. The sample included 7 exfoliated and extracted primary teeth with carious dentin lesions, not reaching the pulp. Each tooth was sectioned longitudinally through the center of the carious lesions into two halves. The teeth were then divided into two groups according to the method of caries removal. Following caries removal, dentin topography and the cut section were examined using the scanning electron microscope. Papacarie produced an irregular, porous, rough and globular dentin appearance. The dentin surfaces were generally free of smear layer, visible bacteria and the dentinal tubules were opened. The dentin cut surfaces showed patent dentinal tubules with open orifices. The drilling method created a smooth and amorphous surface with a continuous smear layer occluding the dentinal tubules. Numerous bacteria were also observed. The cut dentin surfaces showed patent dentinal tubules with their orifices plugged with smear layer. Papacarie produced a rough and porous surface with partial or complete removal of the smear layer and opened dentinal tubules, while the drill produced a smooth surface with uniform smear layer occluding the dentinal tubules.

  12. Invasion of dentinal tubules by oral bacteria.

    Science.gov (United States)

    Love, R M; Jenkinson, H F

    2002-01-01

    Bacterial invasion of dentinal tubules commonly occurs when dentin is exposed following a breach in the integrity of the overlying enamel or cementum. Bacterial products diffuse through the dentinal tubule toward the pulp and evoke inflammatory changes in the pulpo-dentin complex. These may eliminate the bacterial insult and block the route of infection. Unchecked, invasion results in pulpitis and pulp necrosis, infection of the root canal system, and periapical disease. While several hundred bacterial species are known to inhabit the oral cavity, a relatively small and select group of bacteria is involved in the invasion of dentinal tubules and subsequent infection of the root canal space. Gram-positive organisms dominate the tubule microflora in both carious and non-carious dentin. The relatively high numbers of obligate anaerobes present-such as Eubacterium spp., Propionibacterium spp., Bifidobacterium spp., Peptostreptococcus micros, and Veillonella spp.-suggest that the environment favors growth of these bacteria. Gram-negative obligate anaerobic rods, e.g., Porphyromonas spp., are less frequently recovered. Streptococci are among the most commonly identified bacteria that invade dentin. Recent evidence suggests that streptococci may recognize components present within dentinal tubules, such as collagen type I, which stimulate bacterial adhesion and intra-tubular growth. Specific interactions of other oral bacteria with invading streptococci may then facilitate the invasion of dentin by select bacterial groupings. An understanding the mechanisms involved in dentinal tubule invasion by bacteria should allow for the development of new control strategies, such as inhibitory compounds incorporated into oral health care products or dental materials, which would assist in the practice of endodontics.

  13. Missing Concepts in De Novo Pulp Regeneration.

    Science.gov (United States)

    Huang, G T-J; Garcia-Godoy, F

    2014-08-01

    Regenerative endodontics has gained much attention in the past decade because it offers an alternative approach in treating endodontically involved teeth. Instead of filling the canal space with artificial materials, it attempts to fill the canal with vital tissues. The objective of regeneration is to regain the tissue and restore its function to the original state. In terms of pulp regeneration, a clinical protocol that intends to reestablish pulp/dentin tissues in the canal space has been developed--termed revitalization or revascularization. Histologic studies from animal and human teeth receiving revitalization have shown that pulp regeneration is difficult to achieve. In tissue engineering, there are 2 approaches to regeneration tissues: cell based and cell free. The former involves transplanting exogenous cells into the host, and the latter does not. Revitalization belongs to the latter approach. A number of crucial concepts have not been well discussed, noted, or understood in the field of regenerative endodontics in terms of pulp/dentin regeneration: (1) critical size defect of dentin and pulp, (2) cell lineage commitment to odontoblasts, (3) regeneration vs. repair, and (4) hurdles of cell-based pulp regeneration for clinical applications. This review article elaborates on these missing concepts and analyzes them at their cellular and molecular levels, which will in part explain why the non-cell-based revitalization procedure is difficult to establish pulp/dentin regeneration. Although the cell-based approach has been proven to regenerate pulp/dentin, such an approach will face barriers--with the key hurdle being the shortage of the current good manufacturing practice facilities, discussed herein. © International & American Associations for Dental Research.

  14. Effects of demineralized dentin matrix on proliferation and odontogenic differentiation of human dental pulp stem cells in vitro%脱矿牙本质基质对人牙髓干细胞体外增殖、牙向分化能力的影响

    Institute of Scientific and Technical Information of China (English)

    张红梅; 金岩; 王永刚; 张晓梅; 谭家莉; 荀文兴; 杨海珍; 李蓉; 庞楠; 曾光

    2012-01-01

    目的 观察脱矿牙本质基质(demineralized dentin matrix,DDM)与人牙髓干细胞(human dental pulp stem cells,hDP-SCs)的生物相容性及其作为支架材料的牙向诱导作用.方法 体外分离培养DPSCs,分别用四唑盐比色法(MTS)、茜素红染色法、碱性磷酸酶(alkaline phosphatase,ALP)和逆转录聚合酶链式反应(reverse transcription- polymerase chain reaction,RTPCR)方法观察DDM生物材料对DPSCs增殖活性和牙向分化能力的影响.结果 DDM显著地刺激体外培养的DPSCs增殖,诱导了细胞的矿化和提高细胞ALP活性.RT- PCR结果显示DDM诱导后细胞mRNA水平表达牙本质涎磷蛋白(dentin sialophosphoprotein,DSPP)和牙本质基质蛋白(dentin matrix protein1,DMP -1).结论 体外培养条件下,DDM与DPSCs有良好的生物相容性,作为支架材料对于DPSCs有较好牙向诱导作用.%Objective To observe the adhesion and growth of human dental pulp stem cells seeded on demineralized dentin matrix ( DDM) in vitro and the adontogenic induction of DOM. Methods OPSCs were successfully isolated and cultured. The compatibility of the biomaterial was evaluated by MTS assay. The odontogenic differentiation of DPSCs induced by DDM was measured using Alizarin red staining, the alkaline phosphatase (ALP) activity and reverse transcription-polymerase chain reaction (RT-PCR) assay. Results The proliferation of DPSCs in DDM groups was obviously higher than that in the control groups. The higher levels of ALP activity and larger mineralizing nods were also detected in the experimental groups. RT-PCR demonstrated mRNA expression of dentin sialophosphoprotein ( DSPP ) and dentin matrix protein 1 (DMP-1) in DPSCs induced by DDM. Conclusions DDM possesses a good cellular compatibility with DPSCs, As an engineering scaffold.it can induce the odontogenic differentiation of DPSCs.

  15. Innovative endodontic therapy for anti-inflammatory direct pulp capping of permanent teeth with a mature apex

    Science.gov (United States)

    Komabayashi, Takashi; Zhu, Qiang

    2010-01-01

    Direct pulp capping is a treatment of an exposed vital pulp with a dental material to facilitate the formation of reparative dentin and maintenance of vital pulp. It has been studied as an alternate way to avoid vital pulp extirpation. However, the success rate of pulp capping is much lower than that of vital pulp extirpation. Therefore, direct pulp capping is currently considered controversial by many clinicians. To increase success rate, a critical need exists to develop new biologically-based therapeutics that reduce pulp inflammation, promote the continued formation of new dentin-pulp complex, and restore vitality by stimulating the regrowth of pulpal tissue. Bioengineered anti-inflammatory direct pulp capping materials, together with adhesive materials for leakage prevention, have great potential to improve the condition of the existing pulp from an inflamed to a non-inflamed status and lead to a high rate of long-term success. PMID:20416524

  16. Bonding over Dentin Replacement Materials.

    Science.gov (United States)

    Meraji, Naghmeh; Camilleri, Josette

    2017-08-01

    Dentin replacement materials are necessary in large cavities to protect the pulp and reduce the bulk of filling material. These materials are layered with a composite resin restorative material. Microleakage caused by poor bonding of composite resin to underlying dentin replacement material will result in pulp damage. The aim of this study was to characterize the interface between dentin replacement materials and composite resin and to measure the shear bond strength after dynamic aging. Biodentine (Septodont, Saint Maur-des-Fosses, France), Theracal LC (Bisco, Schaumburg, IL), and Fuji IX (GC, Tokyo, Japan) were used as dentin replacement materials. They were then overlaid with a total-etch and bonding agent or a self-etch primer and composite resin or a glass ionomer cement. All combinations were thermocycled for 3000 cycles. The interface was characterized using scanning electron microscopy and elemental mapping. Furthermore, the shear bond strength was assessed. The Biodentine surface was modified by etching. The Theracal LC and Fuji IX microstructure was unchanged upon the application of acid etch. The Biodentine and glass ionomer interface showed an evident wide open space, and glass particles from the glass ionomer adhered to the Biodentine surface. Elemental migration was shown with aluminum, barium, fluorine, and ytterbium present in Biodentine from the overlying composite resin. Calcium was more stable. The bond strength between Theracal LC and composite using a total-etch technique followed by self-etch primer achieved the best bond strength values. Biodentine exhibited the weakest bond with complete failure of bonding shown after demolding and thermocycling. Dynamic aging is necessary to have clinically valid data. Bonding composite resin to water-based dentin replacement materials is still challenging, and further alternatives for restoration of teeth using such materials need to be developed. Copyright © 2017 American Association of Endodontists

  17. Missing Concepts in De Novo Pulp Regeneration

    OpenAIRE

    Huang, G.T.-J.; Garcia-Godoy, F.

    2014-01-01

    Regenerative endodontics has gained much attention in the past decade because it offers an alternative approach in treating endodontically involved teeth. Instead of filling the canal space with artificial materials, it attempts to fill the canal with vital tissues. The objective of regeneration is to regain the tissue and restore its function to the original state. In terms of pulp regeneration, a clinical protocol that intends to reestablish pulp/dentin tissues in the canal space has been d...

  18. 基质细胞衍生因子1α及其受体CXCR4在牙本质-牙髓复合体损伤修复过程中的表达%The expression of stromal cell derived factor 1 a and its receptor CXCR4 in injured dentin-dental pulp

    Institute of Scientific and Technical Information of China (English)

    栗世洋; 张莹; 齐春子; 张云松; 余擎

    2011-01-01

    目的:通过构建牙本质-牙髓复合体损伤修复动物模型,研究基质细胞衍生因子1α 及其受体CXCR4(SDF-1α /CXCR4)在其损伤修复过程中的表达.方法:制备大鼠牙本质-牙髓损伤模型,通过免疫组织化学染色、PCR技术分别对损伤后0、6 h和1、3、7 d及正常大鼠牙髓标本中SDF-1α /CXCR4进行检测.结果:正常大鼠组牙髓中没有发现SDF-1α 、CXCR4阳性表达,实验大鼠组损伤6 h后少量的成牙本质细胞和前期牙本质开始出现较弱阳性表达,损伤1 d后成牙本质细胞阳性表达增强,损伤3 d后牙髓成纤维细胞出现阳性表达,损伤7 d后未分化间充质细胞出现阳性表达,大鼠牙髓损伤后SDF-1α 、CXCR4随着时间的增加阳性表达程度明显增强.图像分析结果显示,SD大鼠牙本质-牙髓复合体损伤后牙髓中SDF-1α 、CXCR4的表达(灰度值)除0 h外其余各组均高于对照组(P<0.05).PCR结果显示,损伤后大鼠牙髓中SDF-1α 、CXCR4均符合产物设计大小.其表达(灰度值)除0 h外其余各组均高于对照组(P<0.05).结论:大鼠牙本质-牙髓复合体损伤后,前期牙本质、成牙本质细胞、牙髓成纤维细胞和未分化间充质细胞对SDF-1α 、CXCR4的表达呈时间依赖性,提示SDF-1α 、CXCR4可能参与了修复性牙本质的形成.%AIM : To investigate the expression and effect of stomal ceU derived factor 1 alpha ( SDF-1α) and its receptor CXCR4 in the rehabilitation process of dentin-dental pulp injury by establishing an arumal model of dentin-dental pulp injury rehabilitation.MEIHODS: A rat model of dental pulp-dentin injury was established.SDF-Ia and CXCR4 expression in dental pulp samples at the moment of O h, 6 h, 1 d, 3 d, 7 d after injury and in normal pulp was detected by immunohiscochemical staining (IHC) and RT-PCR.RESULTS : No positive staining of SDF-1α and CXCR4 was detected in normal dental pulp samples by IHC.6 h after injury, weak expression of SDF-Ia and CXCR4

  19. Is pulp regeneration necessary for root maturation?

    Science.gov (United States)

    Nosrat, Ali; Li, Kevin L; Vir, Kunwar; Hicks, M Lamar; Fouad, Ashraf F

    2013-10-01

    True regeneration of the dental pulp-dentin complex in immature teeth with necrotic pulps has not been shown histologically. It is not known to what extent this true tissue regeneration is necessary to achieve clinically acceptable outcomes. This case report describes the treatment of a patient with an immature maxillary right central incisor with a history of impact trauma and enamel-dentin crown fracture. A diagnosis of pulp necrosis with acute apical abscess was established. A regenerative endodontic protocol that used a paste containing Augmentin for 5 weeks as an intracanal medicament was used. Follow-ups at 9, 12, 17, and 31 months revealed complete osseous healing of the periapical lesion and formation of the root apex, but without increase in root length. Clinically, the tooth was functional, asymptomatic, and nonresponsive to pulp vitality tests. The crown discolored over time. On reentering the root canal, no tissues were observed under magnification inside the root canal space. The root canal treatment was completed with mineral trioxide aggregate obturation. Augmentin might be an acceptable choice for root canal disinfection in regenerative endodontic procedures. The protocol for regenerative endodontic treatment is not predictable for pulp-dentin regeneration. Formation of the root apex is possible without pulp regeneration. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  20. Influence of post-bleaching time intervals on dentin bond strength.

    Science.gov (United States)

    Teixeira, Erica Cappelletto Nogueira; Turssi, Cecilia Pedroso; Hara, Anderson Takeo; Serra, Mônica Campos

    2004-01-01

    It has been reported that bond strength of resin to tooth structure can be reduced when the bonding procedure is carried out immediately after the bleaching treatment. This study evaluated the effect of bleaching of non-vital teeth bleaching on the shear bond strength (SBS) of composite resin/bovine dentin interface and the influence of delaying the bonding procedures for different time intervals following internal bleaching. According to a randomized block design, composite resin cylinders (Z100/Single bond - 3M) were bonded to the flattened dentin surface of two hundred and fifty-six teeth which had previously been subjected to four different treatments: SPH - sodium perborate + 30% hydrogen peroxide; SPW - sodium perborate + distilled water; CP - 37% carbamide peroxide; and CON - distilled water (control), each one followed by storage in artificial saliva for 0 (baseline), 7, 14, and 21 days after bleaching (n = 16). The bleaching agents in the pulp chambers were replaced every 7 days, over 4 weeks. The SBS test of the blocks was done using a universal testing machine. The ANOVA showed that there was no significant interaction between time and bleaching agents, and that the factor time was not statistically significant (p > 0.05). For the factor bleaching treatment, the Student's t-test showed that [CON = CP] > [SPW = SPH]. The bleaching of non-vital teeth affected the resin/dentin SBS values when sodium perborate mixed with 30% hydrogen peroxide or water was used, independently of the elapsed time following the bleaching treatment.

  1. Pulp regeneration: Current approaches and future challenges

    Directory of Open Access Journals (Sweden)

    Jingwen eYANG

    2016-03-01

    Full Text Available Regenerative endodontics aims to replace inflamed/necrotic pulp tissues with regenerated pulp-like tissues to revitalize teeth and improve life quality. Pulp revascularization case reports, which showed successful clinical and radiographic outcomes, indicated the possible clinical application of pulp regeneration via cell homing strategy. From a clinical point of view, functional pulp-like tissues should be regenerated with the characterization of vascularization, re-innervation, and dentin deposition with a regulated rate similar to that of normal pulp. Efficient root canal disinfection and proper size of the apical foramen are the two requisite preconditions for pulp regeneration. Progress has been made on pulp regeneration via cell homing strategies. This review focused on the requisite preconditions and cell homing strategies for pulp regeneration. In addition to the traditionally used mechanical preparation and irrigation, antibiotics, irrigation assisted with EndoVac apical negative-pressure system, and ultrasonic and laser irradiation are now being used in root canal disinfection. In addition, pulp-like tissues could be formed with the apical foramen less than 1 mm, although more studies are needed to determine the appropriate size. Moreover, signaling molecules including stromal cell derived factor (SDF-1α, basic Fibroblast Growth Factor (bFGF, Platelet Derived Growth Factor (PDGF, stem cell factor (SCF, and Granulocyte Colony-Stimulating Factor (G-CSF were used to achieve pulp-like tissue formation via a cell homing strategy. Studies on the cell sources of pulp regeneration might give some indications on the signaling molecular selection. The active recruitment of endogenous cells into root canals to regenerate pulp-like tissues is a novel concept that may offer an unprecedented opportunity for the near-term clinical translation of current biology-based therapies for dental pulp regeneration.

  2. Pulp Regeneration: Current Approaches and Future Challenges.

    Science.gov (United States)

    Yang, Jingwen; Yuan, Guohua; Chen, Zhi

    2016-01-01

    Regenerative endodontics aims to replace inflamed/necrotic pulp tissues with regenerated pulp-like tissues to revitalize teeth and improve life quality. Pulp revascularization case reports, which showed successful clinical and radiographic outcomes, indicated the possible clinical application of pulp regeneration via cell homing strategy. From a clinical point of view, functional pulp-like tissues should be regenerated with the characterization of vascularization, re-innervation, and dentin deposition with a regulated rate similar to that of normal pulp. Efficient root canal disinfection and proper size of the apical foramen are the two requisite preconditions for pulp regeneration. Progress has been made on pulp regeneration via cell homing strategies. This review focused on the requisite preconditions and cell homing strategies for pulp regeneration. In addition to the traditionally used mechanical preparation and irrigation, antibiotics, irrigation assisted with EndoVac apical negative-pressure system, and ultrasonic and laser irradiation are now being used in root canal disinfection. In addition, pulp-like tissues could be formed with the apical foramen less than 1 mm, although more studies are needed to determine the appropriate size. Moreover, signaling molecules including stromal cell derived factor (SDF-1α), basic Fibroblast Growth Factor (bFGF), Platelet Derived Growth Factor (PDGF), stem cell factor (SCF), and Granulocyte Colony-Stimulating Factor (G-CSF) were used to achieve pulp-like tissue formation via a cell homing strategy. Studies on the cell sources of pulp regeneration might give some indications on the signaling molecular selection. The active recruitment of endogenous cells into root canals to regenerate pulp-like tissues is a novel concept that may offer an unprecedented opportunity for the near-term clinical translation of current biology-based therapies for dental pulp regeneration.

  3. Pulp Regeneration: Current Approaches and Future Challenges

    Science.gov (United States)

    Yang, Jingwen; Yuan, Guohua; Chen, Zhi

    2016-01-01

    Regenerative endodontics aims to replace inflamed/necrotic pulp tissues with regenerated pulp-like tissues to revitalize teeth and improve life quality. Pulp revascularization case reports, which showed successful clinical and radiographic outcomes, indicated the possible clinical application of pulp regeneration via cell homing strategy. From a clinical point of view, functional pulp-like tissues should be regenerated with the characterization of vascularization, re-innervation, and dentin deposition with a regulated rate similar to that of normal pulp. Efficient root canal disinfection and proper size of the apical foramen are the two requisite preconditions for pulp regeneration. Progress has been made on pulp regeneration via cell homing strategies. This review focused on the requisite preconditions and cell homing strategies for pulp regeneration. In addition to the traditionally used mechanical preparation and irrigation, antibiotics, irrigation assisted with EndoVac apical negative-pressure system, and ultrasonic and laser irradiation are now being used in root canal disinfection. In addition, pulp-like tissues could be formed with the apical foramen less than 1 mm, although more studies are needed to determine the appropriate size. Moreover, signaling molecules including stromal cell derived factor (SDF-1α), basic Fibroblast Growth Factor (bFGF), Platelet Derived Growth Factor (PDGF), stem cell factor (SCF), and Granulocyte Colony-Stimulating Factor (G-CSF) were used to achieve pulp-like tissue formation via a cell homing strategy. Studies on the cell sources of pulp regeneration might give some indications on the signaling molecular selection. The active recruitment of endogenous cells into root canals to regenerate pulp-like tissues is a novel concept that may offer an unprecedented opportunity for the near-term clinical translation of current biology-based therapies for dental pulp regeneration. PMID:27014076

  4. Dentine in a capsule: Clinical case reports

    Directory of Open Access Journals (Sweden)

    Mallikarjuna Kenchappa

    2015-01-01

    Full Text Available Biodentine TM , a calcium silicate based material has been popular now and can be used as an alternative to mineral trioxide aggregate (MTA due to superior physical and biologic properties. It has been known by several terms as Biodentine, dentin substitute, and RD 94. It has varied clinical applications such as apexification, apexogenesis, pulpotomy, internal resorption, root perforation repair, retrograde filling, pulp capping procedure, and dentin replacement. This article describes the clinical case reports using Biodentine in apexification, apexogenesis, pulpotomy, and root perforation repair.

  5. Immediate and delayed micro-tensile bond strength of different luting resin cements to different regional dentin

    OpenAIRE

    Ali, Abdelraheem Mohamed; Hamouda, Ibrahim Mohamed; Ghazy, Mohamed Hamed; Abo-Madina, Manal Mohamed

    2012-01-01

    We sought to evaluate immediate and delayed micro-tensile bond strength of Panavia F2.0 and Multilink Sprint resin cement to superficial, deep and cervical dentin. Thirty-six freshly extracted non-carious human molars were sectioned in the mesiodistal direction to expose three different dentin regions including superficial dentin (1 mm below the dentine-enamel junction), deep dentin (1 mm above the highest pulp horn) and cervical dentin (0.5 mm above the cemento-enamel junction and 0.5 mm bel...

  6. Effects of low-intensity GaAlAs laser radiation ({lambda}=660 nm) on dentine-pulp interface after class I cavity preparation; Efeitos da radiacao laser GaAlAs ({lambda}=660 nm) em baixa intensidade na interface dentina-polpa pos-preparo cavitario classe 1

    Energy Technology Data Exchange (ETDEWEB)

    Godoy, Bruno Miranda

    2003-07-01

    The aim of this study was to investigate the effects of low-intensity irradiation with GaAlAs laser (red emission) on the ultrastructure of dentine-pulp interface after conventionally prepared class I cavity preparation. Two patients with 8 premolars for extraction indicated for orthodontic reasons. Class I cavities were prepared in these teeth that were then divided into two groups. The first group received a treatment with laser with continuous emission, {lambda}=660 nm, with maximum power output of 30 mW. The dosimetry applied was of approximately 2J/cm{sup 2}, directly and perpendicularly into the cavity in only one section. After the irradiation, the cavities were filled with composite resin. The second group received the same treatment, except by the laser therapy. Twenty-eight days after the preparation, the teeth were extracted and were processed for transmission electron microscopy analysis. Two sound teeth, without any preparation, were also studied. The irradiated group presented odontoblastic processes in higher contact with the extracellular matrix and the collagen fibers appeared more aggregated and organized than those of control group. These results were also observed in the healthy-teeth. Thus, we suggest that laser irradiation accelerates the recovery of the dental structures involved in the cavity preparation at the pre-dentine level. (author)

  7. Trans-dentinal stimulation of tertiary dentinogenesis.

    Science.gov (United States)

    Smith, A J; Murray, P E; Sloan, A J; Matthews, J B; Zhao, S

    2001-08-01

    Trans-dentinal stimulation of tertiary dentinogenesis has long been recognized, and has traditionally been ascribed to diffusion of irritant substances arising during injury and restorative treatment. Identification of bio-active components, especially growth factors including TGF-beta s, sequestered within dentin matrix provides a new explanation for cellular signaling during tertiary dentinogenesis. Both isolated dentin matrix components and pure growth factors (TGF-beta s) have been shown to signal cellular events leading to reactionary and reparative tertiary dentinogenesis. Release of these bio-active components from dentin matrix may arise during carious attack and other injury to the tissue, and also during subsequent surgical intervention and restoration of the tooth. Both cavity-conditioning agents and leaching from restorative materials may contribute to release of these components. Distance of diffusion, as determined by cavity residual dentin thickness, and other restorative parameters may influence the signaling process after release of these components. Careful consideration of the interplay between tissue injury and surgical and restorative material factors is required for optimum exploitation of the exquisite regenerative capacity of dentin-pulp for more biological approaches to clinical treatment of dental disease.

  8. Effect of dentin desensitizing procedures on methyl methacrylate ...

    African Journals Online (AJOL)

    2013-10-29

    Oct 29, 2013 ... To the cementoenamel junction of each tooth a polypropylene chamber .... Dentin thicknesses were measured from five points (two at .... For the first 10 min, the monomer diffusion was the .... with occlusal erosion and attrition.

  9. Clinical management of infected root canal dentin.

    Science.gov (United States)

    Love, R M

    1996-08-01

    Several hundred different species of bacteria are present in the human intraoral environment. Bacterial penetration of root canal dentin occurs when bacteria invade the root canal system. These bacteria may constitute a reservoir from which root canal reinfection may occur during or after endodontic treatment. The learning objective of this article is to review endodontic microbiology, update readers on the role of bacteria in pulp and periapical disease, and discuss the principles of management of infected root canal dentin. Complete debridement, removal of microorganisms and affected dentin, and chemomechanical cleansing of the root canal are suggested as being the cornerstones of successful endodontic therapy, followed by intracanal medication to remove residual bacteria, when required.

  10. Human dental pulp stem cells with highly angiogenic and neurogenic potential for possible use in pulp regeneration.

    Science.gov (United States)

    Nakashima, Misako; Iohara, Koichiro; Sugiyama, Masahiko

    2009-01-01

    Dental caries is a common public health problem, causing early loss of dental pulp and resultant tooth loss. Dental pulp has important functions to sustain teeth providing nutrient and oxygen supply, innervation, reactionary/reparative dentin formation and immune response. Regeneration of pulp is an unmet need in endodontic therapy, and angiogenesis/vasculogenesis and neurogenesis are critical for pulp regeneration. Permanent and deciduous pulp tissue is easily available from teeth after extraction without ethical issues and has potential for clinical use. In this review, we introduce some stem cell subfractions, CD31(-)/CD146(-) SP cells and CD105(+) cells with high angiogenic and neurogenic potential, derived from human adult dental pulp tissue. Potential utility of these cells is addressed as a source of cells for treatment of cerebral and limb ischemia and pulp inflammation complete with angiogenesis and vasculogenesis.

  11. A comparison of human dental pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents.

    Science.gov (United States)

    Jalan, Anushka Lalit; Warhadpande, Manjusha M; Dakshindas, Darshan M

    2017-01-01

    Direct pulp capping involves the placement of a biocompatible agent on pulp tissue that has been inadvertently exposed from traumatic injury or by iatrogenic means. To compare the human pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents. Pulp exposures were performed on the pulpal floor of forty human permanent premolars. The exposure sites were dressed with either Dycal or Biodentine as pulp-capping materials. After 45 days, teeth were extracted and processed for histological examination. The histological data were subjected to Wilcoxon rank-sum test. The dentinal bridges in teeth that were capped with Biodentine were significantly thicker (P Biodentine can be suggested as the material of choice for direct pulp capping procedure instead of Dycal. However, further long-term follow-up in vivo human studies using Biodentine on cariously exposed pulpal teeth are warranted to derive a definite conclusion.

  12. Chronic Inflammation and Angiogenic Signaling Axis Impairs Differentiation of Dental-Pulp Stem Cells: e113419

    National Research Council Canada - National Science Library

    Michael Boyle; Crystal Chun; Chelsee Strojny; Raghuvaran Narayanan; Amelia Bartholomew; Premanand Sundivakkam; Satish Alapati

    2014-01-01

      Dental-pulp tissue is often exposed to inflammatory injury. Sequested growth factors or angiogenic signaling proteins that are released following inflammatory injury play a pivotal role in the formation of reparative dentin...

  13. Caries-resistant bonding layer in dentin.

    Science.gov (United States)

    Zhou, Wei; Niu, Li-Na; Hu, Lin; Jiao, Kai; Chang, Gang; Shen, Li-Juan; Tay, Franklin R; Chen, Ji-Hua

    2016-09-07

    The present study examined the mechanism for caries resistance and the pulp responses in vital teeth following the use of the augmented-pressure adhesive displacement technique. Dentin adhesives were applied to the surface of sound dentin disks in 4 experimental groups: non-antibacterial adhesive and gentle adhesive displacement (N-G), non-antibacterial adhesive and augmented-pressure adhesive displacement (N-H), antibacterial adhesive and gentle adhesive displacement (A-G), antibacterial adhesive and augmented-pressure adhesive displacement (A-H). The depth of demineralization induced by biological or chemical demineralization models was measured using confocal laser scanning microscopy and analyzed with two-way ANOVA. Pulp responses of vital dog's teeth to the augmented-pressure adhesive displacement technique were evaluated using light microscopy. Depth of demineralization was significantly affected by "adhesive type" and "intensity of adhesive displacement" for biological demineralization. For chemical demineralization, only "intensity of adhesive displacement" showed significant influence on lesion depth. Pulp response of 0.1, 0.2 and 0.3 MPa groups showed only moderate disorganization of the odontoblast layer at 24 hours that completely re-organized after 3 weeks. Augmented-pressure adhesive displacement improves the caries resistance property of bonded dentin and does not cause irreversible pulpal damage to vital teeth when the air pressure employed is equal or smaller than 0.3 MPa.

  14. Mineral content of the dentine remaining after chemomechanical caries removal.

    Science.gov (United States)

    Yip, H K; Beeley, J A; Stevenson, A G

    1995-01-01

    Although the dentine remaining after chemomechanical caries removal appears sound by normal clinical criteria, no definitive evidence has yet been obtained to confirm that the dentine surface is in fact mineralised. The aim of this study was to use backscattered electron (BSE) imaging and electron probe micro-analysis (EPMA) to ascertain the level of mineralisation of the dentine remaining in cavities prepared by this technique. Carious dentine was removed from carious lesions by means of N-monochloro-DL-2-aminobutyric acid (NMAB) or NMAB containing 2 mol/l urea. Sections of teeth in which caries removal was complete by normal clinical criteria were examined by EPMA and BSE. Dentine adjacent to the pulp was found to be less mineralised than the surrounding dentine. Although the superficial layer of dentine remaining on the cavity floors frequently appeared to have a slightly reduced mineral content, the results clearly indicated that there was no significant difference between this dentine and the underlying sound dentine.

  15. Multi-factoriality of dentine hypersensitivity

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    Stojšin Ivana

    2008-01-01

    Full Text Available Introduction. Dentine hypersensitivity has been defined as a sharp, short pain arising from exposed dentin in response to stimuli typically thermal, evaporative tactile, osmoticor, chemical and which cannot be ascribed to any other form of dental defect or pathology. Prevalence. The most affected patients range in age from 20 to 40. The following teeth tend to be most sensitive: cuspids, premolars and incisors, location-concentrated on the facial surface. Morphological bases of dentine hypersensitivity Sensitive teeth have much greater numbers of open tubules per unit area and the average diameter of tubules is almost 2 times greater than tubules in nonsensitive teeth. Mechanisms of dentine hypersensitivity. The most widely accepted theory of how the pain occurs is Brannstroms theory. Etiology Dentine hypersensitivity represents a condition of presumable multifactorial pathology. Two processes are essential for its development: (1 dentin must be exposed through either genetic disturbance, enamel defect (lamellae, tufts and spindles, loss of enamel (erosion, abrasion, attrition, abfraction, gingival recession with rapid loss of cementum and (2 the dentin tubules must be open to both the oral cavity and the pulp. Diagnosis. Diagnostic protocol for this condition consisted of Medical, Dental Dietary, Oral Hygiene History and Intra-oral examinations with air indexing method. Differential Diagnosis: We must take into consideration a number of variables such as: dental caries, cracked tooth, restorative sensitivity, medication sensitivity, bleaching sensitivity and abscessed or non-vital tooth. Conclusion. Dentin hypersensitivity is a problem that bothes many patients. Many conditions share the symptoms of tooth sensitivity so differential diagnosis is essential for suitable treatment or preventive measures.

  16. Perbandingan kekerasan mikro dentin mahkota setelah aplikasi berbagai bahan bleaching intrakoronal

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    Apriko Merza

    2016-12-01

    Full Text Available Comparing microhardness of dentine crown after application of various intracoronal bleaching agents. The aim of this study is to compare microhardness of dentine crown after treatment with intracoronal bleaching agents. The method of this study was an experimental laboratory. Thirty two extracted human mandibular first premolars without caries, sectioned at 2 mm below Cemento-Enamel Junction were divided into four groups and bleaching agents were sealed into the pulp chambers as follows: group A – 45% carbamide peroxide, group B – 35% hydrogen peroxide, group C – sodium perborate mixed aquadest and group D – aquadest. Access cavities were sealed and then stored in aquadest at 37 °C. Bleaching procedures were performed on days 0, 7, 14 and 21. After 28 days, the teeth were sectioned longitudinally, and planted on acrylyc. Microhardness of dentine crown was measured by vickers microhardness tester. One Way ANOVA and LSD were used to evaluate the effect of intracoronal bleaching agents on microhardness of dentine crown. The results showed that average values of microhardness of dentine crown on group A was 45,04 VHN, group B was 45,42 VHN, group C was 55,22 VHN and group D was 55,63 VHN. In clonclusion, there was si gnificantly different microhardness of dentine crown between group 45% carbamide peroxide and 35% hidrogen peroxide with sodium perborate mixed aquadest, but between group 45% carbamide peroxide with 35% hidrogen peroxide there was no significant difference. ABSTRAK Tujuan penelitian ini untuk mengetahui perbandingan kekerasan mikro dentin mahkota setelah aplikasi berbagai bahan bleaching intrakoronal. Jenis penelitian ini merupakan penelitian eksperimental laboratoris. Sebanyak 32 gigi premolar pertama mandibula tanpa karies, telah diekstraksi, dipotong 2 mm di bawah cemento-enamel junction dibagi dalam 4 kelompok dan bahan bleaching dimasukkan ke dalam kamar pulpa, yaitu kelompok A – 45% karbamid peroksida, kelompok B -35

  17. RAT DENTAL PULP RESPONSE TO PROPOLIS AS A DIRECT PULP CAPPING AGENT

    Directory of Open Access Journals (Sweden)

    Sabir Ardo

    2006-04-01

    Full Text Available The aim of the present study was to assess the response of rat dental pulp to direct pulp capping with ethanol extracts of propolis (EEP. An occlusal cavity was prepared on the right maxillary first molar of Spraque-Dawley rats. The dental pulp was exposed and the lined with a zinc-oxide based filler as a control (group I, or with EEP (group II. Then, each cavity was filled with glass ionomer cement. The animals were sacrificed at week 1, 2, or 4. Biopsy samples were obtained, and these were stained and viewed by a light microscope. The histological examination was based on the presence of polymorph nuclear leukocytes and macrophages, and also the dentinal bridge formation. Data were statistically analysed using Kruskall-Wallis and Mann-Whitney tests. The results showed that the inflammatory response of EEP group was relatively milder compared to the control group, but there was no significant difference (p>0.05 between the two groups. There was no dentinal bridge formation seen in both groups. Therefore, the present results suggest that direct pulp capping with EEP in rats may delay pulp inflammatory process and fail to stimulate reparative dentin.

  18. Histological evaluation of direct pulp capping with novel nanostructural materials based on active silicate cements and Biodentine® on pulp tissue

    Directory of Open Access Journals (Sweden)

    Popović-Bajić Marijana

    2013-01-01

    Full Text Available The aim of this study was to examine the effect of Biodentine® and two new nanostructured materials based on active silicate cements on exposed tooth pulp of Vietnamese pigs. The study comprised 40 teeth in two Vietnamese pigs (24 months old. After class V cavity preparation, the pulp on each tooth was exposed using a small round bur. The following materials were applied on pulp exposures: Biodentine® (10 teeth, ALBO MPCA-I (10 teeth, and ALBO MPCA-II (10 teeth. In the control group, exposed pulp was covered with ProRoot MTA® (10 teeth. After the observation period of 28 days, the animals were sacrificed and the teeth prepared for histological analysis. Light microscope was used for the analysis of dentin bridge formation, tissue reorganization and inflammation, and the presence of bacteria in the pulp. In the group of Biodentine®, a complete dentin bridge was noted in 3 cases, while incomplete dentin bridge in the form of dental islets was detected in 4 cases. Nanostructured material ALBO-MPCA I provided complete dentin bridge formation in 5 teeth, in 3 teeth the formed dentin bridge was incomplete. ALBO MPCA-II showed complete closure of the pulp opening by dentin bridge in 4 samples, while in the same number of teeth it was incomplete. In the control group, 4 teeth showed a complete dentin bridge, whereas in 6 teeth it was incomplete. Histological analysis indicated favourable therapeutic effects of Biodentine® and the two materials ALBO-MPCA I and ALBO-MPCA II after teeth pulp capping in Vietnamese pigs. Pulp reaction was similar to that caused by ProRoot MTA®. [Projekat Ministarstva nauke Republike Srbije, br. ON172026

  19. Hard tissue deposition in dental pulp canal by {alpha}-tricalcium phosphate cement

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, M.; Toda, T. [Osaka Dental Univ. (Japan). Dept. of Endodontics; Mandai, Y. [Bio-Chemical Lab. of Nitta Gelatin Inc., Yao (Japan); Oonishi, H. [Osaka Minami National Hospital, Kawachi (Japan). Dept. of Orthopaedic Surgery

    2001-07-01

    Canal closure by hard tissue proliferation in the pulp canal and/or apical foramen is the most ideal healing after pulp removal. Generally, Ca(OH){sub 2} may induce secondary dentine or dentine-bridge on the amputated pulp surface. However, Ca(OH){sub 2} shows strong alkalinity and may cause severe inflammatory responses in the residual pulp. Moreover, completely formed dentine-bridge at the orifice will disturb further treatment of residual pulp because of the difficulty in localizing the pathway. The purpose of this study was to see hard tissue induction using newly developed {alpha}-tricalcium phosphate cement and to recognize the morphological difference of hard tissue from that of Ca(OH){sub 2}. (orig.)

  20. Histological evaluation of direct pulp capping with all-in-one adhesives in rat teeth.

    Science.gov (United States)

    Shinkai, Koichi; Taira, Yoshihisa; Kawashima, Satoki; Suzuki, Shiro; Suzuki, Masaya

    2017-05-31

    The aim of this study was to histologically evaluate direct pulp capping using different all-in-one adhesives in rat teeth. Five all-in-one adhesives and a control material (MTA) were used. Each material was applied on the exposed pulp, and each cavity was subsequently restored with the resin composite. Rats were sacrificed 14 days after the surgical procedure. Serial stained sections were histologically evaluated for examining pulp tissue disorganization (PTD), inflammatory cell infiltration (ICI), dentin bridge formation (DBF), and bacterial penetration (BP). We found that rat pulps, which were direct capped with all-in-one adhesives, showed various degrees of PTD, ICI, and DBF depending on the material, and that there were no complete dentin bridges. In contrast, rat pulps capped with MTA showed no PTD and ICI, and there were complete dentin bridges in all, but one specimen. No BP was observed in any specimen.

  1. Indirect pulp treatment in a permanent molar: case reort of 4-year follow-up

    Directory of Open Access Journals (Sweden)

    Ticiane Cestari Fagundes

    2009-02-01

    Full Text Available This case report describes the Indirect Pulp Treatment (IPT of deep caries lesion in a permanent molar. A 16-year-old male patient reported discomfort associated with thermal stimulation on the permanent mandibular left first molar. The radiographs revealed a deep distal caries lesion, very close to the pulp, absence of radiolucencies in the periapical region, and absence of periodontal space thickening. Pulp sensitivity was confirmed by thermal pulp vitality tests. Based on the main complaint and the clinical and radiographic examinations, the treatment plan was established to preserve pulp vitality. Clinical procedures consisted of removing the infected dentin and lining the caries-affected dentin with calcium hydroxide paste. The tooth was provisionally sealed for approximately 60 days. After this period, tooth vitality was confirmed, the remaining carious dentin was removed, and the tooth was restored. At 4-year follow-up, no clinical or radiographic pathological findings were found.

  2. Influence of EDTA and dentine in tissue dissolution ability of sodium hypochlorite.

    Science.gov (United States)

    de Almeida, Luiza Helena Silva; Leonardo, Natália Gomes e Silva; Gomes, Ana Paula Neutzling; Souza, Erick Miranda; Pappen, Fernanda Geraldes

    2015-04-01

    This study verified whether ethylenediaminetetraacetic acid (EDTA) influences the pulp tissue dissolution capability of different concentrations of NaOCl, in the presence of dentine. NaOCl and EDTA solutions were simultaneously mixed in flasks either containing a dentine disc or those not containing a dentine disc. Previously weighed bovine pulp tissues were immersed in the solutions for 5, 15 and 30 min. The weight loss was measured. The dissolution tests were performed in triplicate. Univariate analysis of variance, along with further Tukey's honestly significant difference pairwise comparisons, was used to verify the effect of EDTA, different concentrations of NaOCl, dentine and time of incubation on the tissue dissolution. Higher concentrations of NaOCl increased the tissue dissolution. EDTA reduced the capacity of NaOCl to dissolve pulp tissue, even in presence of dentine. Dentine negatively affects the capacity of NaOCl to dissolve pulp tissue. In conclusion, the presence of EDTA and dentine negatively affects the tissue dissolution ability of NaOCl.

  3. Hybridization quality in cervical cementum and superficial dentin using current adhesives.

    Science.gov (United States)

    Yuan, Yang; Shimada, Yasushi; Ichinose, Shizuko; Tagami, Junji

    2008-05-01

    The aim of this research was to determine the hybridization quality of adhesives to gingival cementum and close superficial dentin using both total-etch and self-etch, one-step and two-step adhesives in vitro. Five adhesive systems were used and evaluated in this study; three kinds of two-step adhesives (total-etch--Single Bond and self-etch--Clearfil SE Bond and Clearfil Protect Bond) and two one-step adhesives (Clearfil S3 Bond, G Bond). Fifteen extracted intact human third molars were used in this study. A diagonal cut which was approximately 45 degrees to the long axis of the roots, with the initiating point located 2 mm below the buccal enamel-cementum junction and ascending towards the pulp chamber was prepared on each tooth. Flat cervical cementum and dentin surfaces were ground with wet 600-grit silicon carbide paper, and bonded with one of the adhesives and finished by applying a flowable resin composite. After 24 h storage at 37 degrees C in water, the bonded assemblies were sectioned into approximately 1mm thick slabs. Two central slabs from each tooth were chosen. One slab was totally demineralized in 0.5 M EDTA and the other was not demineralized and immersed into 50% (w/v) solution of ammoniacal silver nitrate for 24 h, and successively exposed to photodeveloping solution for 8 h. The specimens were then processed for TEM observation. Both the stained demineralized silver unchallenged and unstained non-demineralized silver challenged resin-cervical cementum/proximal superficial dentin interface were observed and evaluated under a transmission electron microscope. The nanoleakage pathway and extent vary among the different adhesives used and also between the resin-cementum interface and resin-dentin interface. Two-step self-etch adhesives showed better hybridization quality both in cementum and proximal superficial dentin as compared to those of two-step total-etch adhesive and one-step self-etch adhesives. Two-step self-etch adhesives may provide a

  4. Revascularization in Immature Permanent Teeth with Necrotic Pulp and Apical Pathology: Case Series

    Directory of Open Access Journals (Sweden)

    López Carmen

    2017-01-01

    Full Text Available Introduction. To present and discuss the results of five clinical cases treated using the revascularization protocol, showing clinical and radiographic monitoring. Necrotic immature teeth with periapical pathology present a challenge to dentists because the techniques used in apexification leave the tooth susceptible to fracture, since the root does not continue to grow in length and the canal walls are thin. Revascularization has emerged as an alternative to resolve these deficiencies, enabling apical closure, continued development of the roots, and thickening of the dentinal walls. Case Series. Five clinically and radiographically diagnosed necrotic immature permanent teeth were treated using revascularization treatment. The therapeutic protocol involved accessing the pulp chamber; irrigating copiously with NaOCl; applying a triple antibiotic paste as intracanal dressing; then provisionally sealing it. After 3 weeks, the canal was cleaned and the apex irritated with a size 15 K-file to induce blood that would serve as a scaffold for pulp revascularization. MTA was used to seal the chamber before final obturation (composite or metallic crown. Conclusion. The discussion of the results leads to debate about different restorative materials and other published protocols.

  5. Response of human dental pulp capped with biodentine and mineral trioxide aggregate.

    Science.gov (United States)

    Nowicka, Alicja; Lipski, Mariusz; Parafiniuk, Mirosław; Sporniak-Tutak, Katarzyna; Lichota, Damian; Kosierkiewicz, Anita; Kaczmarek, Wojciech; Buczkowska-Radlińska, Jadwiga

    2013-06-01

    Biodentine is a new bioactive cement that is similar to the widely used mineral trioxide aggregate (MTA). It has dentin-like mechanical properties, which may be considered a suitable material for clinical indications of dentin-pulp complex regeneration such as direct pulp capping. The purpose of the present study was to compare the response of the pulp-dentin complex in human teeth after direct capping with this new tricalcium silicate-based cement with that of MTA. Pulps in 28 caries-free maxillary and mandibular permanent intact human molars scheduled for extraction for orthodontic reasons were mechanically exposed and assigned to 1 of 2 experimental groups, Biodentine or MTA, and 1 control group. Assay of periapical response and clinical examination were performed. After 6 weeks, the teeth were extracted, stained with hematoxylin-eosin, and categorized by using a histologic scoring system. The majority of specimens showed complete dentinal bridge formation and an absence of inflammatory pulp response. Layers of well-arranged odontoblast and odontoblast-like cells were found to form tubular dentin under the osteodentin. Statistical analysis showed no significant differences between the Biodentine and MTA experimental groups during the observation period. Within the limitations of this study, Biodentine had a similar efficacy in the clinical setting and may be considered an interesting alternative to MTA in pulp-capping treatment during vital pulp therapy. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. [The significance of endogenous peptides for dental pulp pain].

    Science.gov (United States)

    Göres, M; Oehme, P; Zuhrt, R

    1989-01-01

    The increase of knowledges in the field of endorphines and other peptides causes new aspects of development and transmission of dental pain. Methionin-enkephalin (ME) and substance P (SP) are found also in the dental pulp and the dentine. The concentration of SP is higher in the pulp, than in some other tissues. The concentration of both, ME and SP, in the endodont is different with respect to different functional situations, e.g. it is lower in case of pain. We suppose, there is a peptiderg reception and transmission of pain in dentine. Interaction with this new system opens new ways for opposing pulpal pain.

  7. How to bond to root canal dentin

    Science.gov (United States)

    Nica, Luminita; Todea, Carmen; Furtos, Gabriel; Baldea, Bogdan

    2014-01-01

    Bonding to root canal dentin may be difficult due to various factors: the structural characteristic of the root canal dentin, which is different from that of the coronal dentin; the presence of the organic tissue of the dental pulp inside the root canal, which has to be removed during the cleaning-shaping of the root canal system; the smear-layer resulted after mechanical instrumentation, which may interfere with the adhesion of the filling materials; the type of the irrigants used in the cleaning protocol; the type of the sealer and core material used in the obturation of the endodontic space; the type of the materials used for the restoration of the endodontically treated teeth. The influence of the cleaning protocol, of the root canal filling material, of the type of the adhesive system used in the restoration of the treated teeth and of the region of the root canal, on the adhesion of several filling and restorative materials to root canal dentin was evaluated in the push-out bond strength test on 1-mm thick slices of endodontically treated human teeth. The results showed that all these factors have a statistically significant influence on the push-out bond strength. Formation of resin tags between radicular dentin and the investigated materials was observed in some of the samples at SEM analysis.

  8. Interferon-gamma improves impaired dentinogenic and immunosuppressive functions of irreversible pulpitis-derived human dental pulp stem cells.

    Science.gov (United States)

    Sonoda, Soichiro; Yamaza, Haruyoshi; Ma, Lan; Tanaka, Yosuke; Tomoda, Erika; Aijima, Reona; Nonaka, Kazuaki; Kukita, Toshio; Shi, Songtao; Nishimura, Fusanori; Yamaza, Takayoshi

    2016-01-18

    Clinically, irreversible pulpitis is treated by the complete removal of pulp tissue followed by replacement with artificial materials. There is considered to be a high potential for autologous transplantation of human dental pulp stem cells (DPSCs) in endodontic treatment. The usefulness of DPSCs isolated from healthy teeth is limited. However, DPSCs isolated from diseased teeth with irreversible pulpitis (IP-DPSCs) are considered to be suitable for dentin/pulp regeneration. In this study, we examined the stem cell potency of IP-DPSCs. In comparison with healthy DPSCs, IP-DPSCs expressed lower colony-forming capacity, population-doubling rate, cell proliferation, multipotency, in vivo dentin regeneration, and immunosuppressive activity, suggesting that intact IP-DPSCs may be inadequate for dentin/pulp regeneration. Therefore, we attempted to improve the impaired in vivo dentin regeneration and in vitro immunosuppressive functions of IP-DPSCs to enable dentin/pulp regeneration. Interferon gamma (IFN-γ) treatment enhanced in vivo dentin regeneration and in vitro T cell suppression of IP-DPSCs, whereas treatment with tumor necrosis factor alpha did not. Therefore, these findings suggest that IFN-γ may be a feasible modulator to improve the functions of impaired IP-DPSCs, suggesting that autologous transplantation of IFN-γ-accelerated IP-DPSCs might be a promising new therapeutic strategy for dentin/pulp tissue engineering in future endodontic treatment.

  9. Sympathetic nerve fibers sprout into rat odontoblast layer, but not into dentinal tubules, in response to cavity preparation.

    Science.gov (United States)

    Shimeno, Yoichi; Sugawara, Yumiko; Iikubo, Masahiro; Shoji, Noriaki; Sasano, Takashi

    2008-04-11

    This study was designed to determine if sympathetic nerve fibers exist in dentinal tubules in rat normal dental pulp, and if they sprout into the dentinal tubules in response to artificial cavity preparation in dentin. Sympathetic nerve fibers in rat molar dental pulp were labeled using an anterograde axonal transport technique involving injection of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) into the superior cervical ganglion (SCG). They were then observed using light and electron microscopes. In normal dental pulp (control), scattered WGA-HRP reaction products were observed in unmyelinated nerve endings in the odontoblast layer and subodontoblastic region. In injured pulp 3 weeks after cavity preparation, reaction products were about 1.8-times more plentiful in the above areas (versus control pulp). However, no labeled nerve fibers were observed in the dentinal tubules in either control or injured dental pulp. These results indicate that although sympathetic nerve fibers do indeed sprout in rat dental pulp in response to cavity preparation, they do not penetrate into the dentinal tubules in which postganglionic nerve endings derived from the SCG were not originally present.

  10. Pulp nerve fibers distribution of human carious teeth: An immunohistochemical study

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    Tetiana Haniastuti

    2010-12-01

    Full Text Available Background: Human dental pulp is richly innervated by trigeminal afferent axons that subserve nociceptive function. Accordingly, they respond to stimuli that induce injury to the pulp tissue. An injury to the nerve terminals and other tissue components in the pulp stimulate metabolic activation of the neurons in the trigeminal ganglion which result in morphological changes in the peripheral nerve terminals. Purpose: The aim of the study was to observe caries-related changes in the distribution of human pulpal nerve. Methods: Under informed consents, 15 third molars with caries at various stages of decay and 5 intact third molars were extracted because of orthodontic or therapeutic reasons. All samples were observed by micro-computed tomography to confirm the lesion condition 3-dimensionally, before decalcifying with 10% EDTA solution (pH 7.4. The specimens were then processed for immunohistochemistry using anti-protein gene products (PGP 9.5, a specific marker for the nerve fiber. Results: In normal intact teeth, PGP 9.5 immunoreactive nerve fibers were seen concentrated beneath the odontoblast cell layer. Nerve fibers exhibited an increased density along the pulp-dentin border corresponding to the carious lesions. Conclusion: Neural density increases throughout the pulp chamber with the progression of caries. The activity and pathogenicity of the lesion as well as caries depth, might influence the degree of neural sprouting.Latar belakang: Pulpa gigi manusia diinervasi oleh serabut saraf trigeminal yang berespon terhadap stimuli penyebab perlukaan dengan menimbulkan rasa sakit. Perlukaan pada akhiran saraf dan komponen lain dari pulpa akan menstimulasi aktivasi metabolik dari neuron pada ganglion trigeminal sehingga mengakibatkan perubahan morfologi pada akhiran saraf perifer. Tujuan: Penelitian ini bertujuan untuk mengamati perubahan distribusi saraf pada pulpa gigi manusia yang disebabkan oleh proses karies. Metode: Penelitian ini menggunakan

  11. [Dentin adhesives. An update].

    Science.gov (United States)

    Grandini, R; Novelli, C; Pierleoni, P

    1991-11-01

    Even if mechanical bonding to enamel utilizing the acid-etch technique has been very successful, adhesion to dentin is still a challenge to researchers and clinicians. Dentin is a vital tissue and differs in composition from enamel: acid-etching does not enhance the bond strength of composite resins to dentin and may elicit a severe pulpal response. For an effective bond to occur, a dentin bonding system has to be used. The first generation of methacrylate-based dentin adhesives was capable of chemical bonding to the inorganic phase of dentin. The chemical basis for this resin-dentin adhesive was the interaction between a phosphate group attached to the methacrylate and the calcium ions on the dentin surface. This system yielded rather low bond strengths which were clinically unsatisfying. The second generation of dentin adhesives became available to the profession recently. Each of these new bonding systems use similar chemical composition for the same purpose of bonding with physicochemical interaction to the hard tooth tissues. All these systems contain a mild acid dentin conditioner to remove the smear layer and an aqueous resin containing primer to improve monomer penetration into the hydrophilic dentin surface. The second generation dentin bonding systems are extremely sensitive to variations upon the completeness of instructions and how accurately these are followed by dental practitioners.

  12. Dentin tubule occluding ability of dentin desensitizers.

    Science.gov (United States)

    Han, Linlin; Okiji, Takashi

    2015-04-01

    To compare the dentin tubule-occluding ability of fluoroaluminocalciumsilicate-based (Nanoseal), calcium phosphate-based (Teethmate Desensitizer), resin-containing oxalate (MS Coat ONE) and diamine silver fluoride (Saforide) dentin desensitizers using artificially demineralized bovine dentin. Simulated hypersensitive dentin was created using cervical dentin sections derived from bovine incisors using phosphoric acid etching followed by polishing with a paste containing hydroxyapatite. The test desensitizers were applied in one, two, or three cycles, where each cycle involved desensitizer application, brushing, and immersion in artificial saliva (n= 5 each). The dentin surfaces were examined with scanning electron microscopy, and the dentin tubule occlusion rate was calculated. The elemental composition of the deposits was analyzed with electron probe microanalysis. Data were analyzed by one-way ANOVA and the Tukey honestly significant different test. Marked deposit formation was observed on the specimens treated with Nanoseal or Teethmate Desensitizer, and tags were detected in the specimens' dentin tubules. These findings became more prominent as the number of application cycles increased. The major elemental components of the tags were Ca, F, and Al (Nanoseal) and Ca and P (Teethmate Desensitizer). The tubule occlusion rates of MS Coat ONE and Saforide were significantly lower than those of Nanoseal and Teethmate Desensitizer (P< 0.05).

  13. Interactions between cavity preparation and restoration events and their effects on pulp vitality.

    Science.gov (United States)

    Wisithphrom, Kessiri; Murray, Peter E; About, Imad; Windsor, L Jack

    2006-12-01

    The purpose of this study was to investigate the precise effect and rank the importance of cavity preparation and restoration variables on human pulp vitality. Fifty-three Class V unexposed cavities were prepared and restored with calcium hydroxide/amalgam, resin-modified glass ionomer, zinc oxide-eugenol, resin composite, or zinc polycarboxylate materials. Pulp vitality was reduced by the remaining dentin thickness of the cavity preparations, whereas the other variables, including the type of restorative material, had little effect. Restorative materials cause minimal pulp damage in isolation; it is more important to minimize the removal of intact dentin to maintain the vitality of teeth.

  14. In vivo assessment of secondary caries and dentin characteristics after traditional amalgam restorations

    Science.gov (United States)

    de Assunção Pinheiro, Isauremi Vieira; Borges, Boniek Castillo Dutra; de Lima, Kenio Costa

    2012-01-01

    Objective This study aimed to evaluate in vivo the occurrence of secondary caries and dentin characteristics in permanent molars after traditional amalgam restorations, by means of clinical visual examination, radiographs and laser-induced fluorescence (LF) (DIAGNOdent). Methods: Thirty first permanent molars of 30 schoolchildren in the 7 to14 year-old age group were included. Caries was removed by hand. Thus, indirect pulp capping was performed with glass-ionomer cement (GIC), the cavity was varnished and amalgam filled. LF was measured before and after cavity preparation and after a 12-month observation period. Dentin color after cavity preparation and after the 12-month observation period was recorded. Recurrent caries was also investigated by visual clinical and radiographic examinations, in addition to dentin thickness between pulp and indirect GIC pulp capping. Data was analyzed by ANOVA for repeated measurements, paired “t” test and descriptive statistic. Results: There were statistically significant differences (P<.05) among LF scores for dentin in all periods evaluated, with the lowest scores shown after 12 month of observation. There was no statistical difference between dentin color after cavity preparation and following 12 months of observation. Moreover, there was no recurrent caries attack at 12-month follow-up; dentin thickness between pulp and indirect GIC pulp capping was similar between baseline and final observation periods. It was concluded that the clinical restorative procedure using hand caries removal, indirect pulp capping with GIC, varnishing and amalgam filling the cavity did not provide secondary caries and increased dentin mineral content after 12 months. PMID:22904654

  15. Effect of delayed light curing of a resin composite on marginal integrity in cylindrical dentine cavities.

    Science.gov (United States)

    Manabe, A; Debari, K; Itoh, K; Hisamitsu, H; Wakumoto, S

    1993-12-01

    The effect of delayed light curing of resin composite on marginal adaptation has been examined by measuring the wall-to-wall polymerization contraction gap when using a commercial resin composite together with experimental dentine bonding systems to restore cylindrical preparations in dentine. Morphological changes in dentine during dentine bonding procedures were observed using a scanning electron microscope. In a previous report, the contraction gap width for a resin composite increased when irradiation of the resin system was delayed, despite the use of a dentine bonding system considered to be 'contraction' gap free. Such deterioration in marginal adaptation was minimized by use of an experimental dentine primer, 40% erythritol methacrylate aqueous solution (EM), followed by the use of a commercial dual- or autocured dentine bonding agent. Under scanning electron microscopy, the dentine surface microstructure became unclear after EM priming, and a polymer film was detected after polymerization of the dual-cured dentine bonding agent. The hydrogelled primer and the formation of a polymer network on the dentine surface may prevent the flow of fluid from the pulp through the dentine tubules, and maintain marginal integrity if there is delay in light curing of light-activated resin composite systems.

  16. Autophagy in SDF-1α-mediated DPSC migration and pulp regeneration.

    Science.gov (United States)

    Yang, Jing-Wen; Zhang, Yu-Feng; Wan, Chun-Yan; Sun, Zhe-Yi; Nie, Shuai; Jian, Shu-Juan; Zhang, Lu; Song, Guang-Tai; Chen, Zhi

    2015-03-01

    Critical morphological requirements for pulp regeneration are tissues replete with vascularisation, neuron formation, and dentin deposition. Autophagy was recently shown to be related to angiogenesis, neural differentiation, and osteogenesis. The present study aimed to investigate the involvement of autophagy in stromal cell-derived factor-1α (SDF-1α)-mediated dental pulp stem cell (DPSC) migration and pulp regeneration, and identify its presence during pulp revascularisation of pulpectomised dog teeth with complete apical closure. In vitro studies showed that SDF-1α enhanced DPSCs migration and optimised focal adhesion formation and stress fibre assembly, which were accompanied by autophagy. Moreover, autophagy inhibitors significantly suppressed, whereas autophagy activator substantially augmented SDF-1α-stimulated DPSCs migration. Furthermore, after ectopic transplantation of tooth fragment/silk fibroin scaffold with DPSCs into nude mice, pulp-like tissues with vascularity, well-organised fibrous matrix formation, and new dentin deposition along the dentinal wall were generated in SDF-1α-loaded samples accompanied by autophagy. More importantly, in a pulp revascularisation model in situ, SDF-1α-loaded silk fibroin scaffolds improved the de novo ingrowth of pulp-like tissues in pulpectomised mature dog teeth, which correlated with the punctuated LC3 and Atg5 expressions, indicating autophagy. Our findings provide novel insights into the pulp regeneration mechanism, and SDF-1α shows promise for future clinical application in pulp revascularisation.

  17. Can miniature pulpotomy procedure improve treatment outcomes of direct pulp capping?

    Science.gov (United States)

    Asgary, Saeed; Ahmadyar, Maryam

    2012-02-01

    Dental pulp exposure is a common incident during dental treatment. If there are clinical signs of pulp vitality, it is recommended to carry out direct pulp capping (DPC) using appropriate pulp covering agents (PCA). The main objectives are maintenance of pulp vitality/healing along with the formation of a calcified bridge beneath the PCA. Our proposed hypothesis is based on consideration of biologic principles in order to achieve improved treatment outcomes of DPC for cariously exposed pulp using miniature pulpotomy procedure (MPP). MPP will result in improved treatment outcomes of DPC by improved maintenance of a clean surgical pulp wound; removal of infected dentin chips/damaged pulp tissue specially injured odontoblast cells; improved proximity/interaction of PCA to undifferentiated mesenchymal/stem cells; better control of bleeding; and creating an improved seal using PCA.

  18. Histological Analysis of Rat dental Pulp Tissue Capped With Propolis

    OpenAIRE

    Ardo Sabir, Dr.drg. M.Kes

    2005-01-01

    The Result Showed that pulp inflammatory occured in groups I and II as early as week 1. No dentin bridge formation was seen in these groups. In constast, there was no evident inflammatory response in group II at week 1. Mild and moderate pulp inflammatory in this group occured at 2 and 4 weeks after treatment, respectively. Partial dental bridge formation was seen in group II at week4. Therefore, the present result suggest that direct pulp caping with propolis flavonoids in rets may delay den...

  19. Frameshift mutations in dentin phosphoprotein and dependence of dentin disease phenotype on mutation location.

    Science.gov (United States)

    Nieminen, Pekka; Papagiannoulis-Lascarides, Lisa; Waltimo-Siren, Janna; Ollila, Päivi; Karjalainen, Sara; Arte, Sirpa; Veerkamp, Jaap; Tallon Walton, Victoria; Chimenos Küstner, Eduard; Siltanen, Tarja; Holappa, Heidi; Lukinmaa, Pirjo-Liisa; Alaluusua, Satu

    2011-04-01

    We describe results from a mutational analysis of the region of the dentin sialophosphoprotein (DSPP) gene encoding dentin phosphoprotein (DPP) in 12 families with dominantly inherited dentin diseases. In eight families (five mutations in the N-terminal third of DPP), the clinical and radiologic features were uniform and compatible with dentin dysplasia type II (DD-II) with major clinical signs in the deciduous dentition. In the other families (four mutations in the more C-terminal part), the permanent teeth also were affected, and the diseases could be classified as variants of dentinogenesis imperfecta. Attrition was not prominent, but periapical infections were common. Discoloring with varying intensity was evident, and pulps and root canals were obliterated in the permanent dentition. All mutations caused a frameshift that replaced the Ser-Ser-Asx repeat by a code for a hydrophobic downstream sequence of approximately original length. We conclude that frameshift mutations in DSPP explain a significant part of dentin diseases. Furthermore, we propose that the location of the mutation is reflected in the phenotypic features as a gradient from DD-II to more severe disease that does not conform to the classic definitions of DI-II. Copyright © 2011 American Society for Bone and Mineral Research.

  20. Dentinal fluid dynamics in human teeth, in vivo.

    Science.gov (United States)

    Ciucchi, B; Bouillaguet, S; Holz, J; Pashley, D

    1995-04-01

    Cavities were prepared in human premolars scheduled for extraction for orthodontic reasons. The smear layer was removed from the dentin surface by acid etching, and the cavity was sealed using a hollow chamber. The chamber was filled with sterile saline solution and connected via tubing to a hydraulic circuit featuring an adjustable pressure reservoir and a device that measures fluid movement across dentin. In the absence of any exogenous pressure, all cavities exhibited an outward fluid flow rate of 0.36 microliters min-1 cm-2. As exogenous pressure was applied to the cavity, the outward flow slowed. The exogenous pressure that stopped outward fluid flow was taken to be equal to normal pulpal tissue pressure. The mean value was 14.1 cm H2O in five teeth. This simple method permits measurement of dentinal fluid flux, the hydraulic conductance of dentin, and estimates pulpal tissue pressure.

  1. 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.

  2. 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.

  3. In vivo model for microbial invasion of tooth root dentinal tubules.

    Science.gov (United States)

    Brittan, Jane L; Sprague, Susan V; Macdonald, Emma L; Love, Robert M; Jenkinson, Howard F; West, Nicola X

    2016-04-01

    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.

  4. In vivo model for microbial invasion of tooth root dentinal tubules

    Directory of Open Access Journals (Sweden)

    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.

  5. Immediate and delayed micro-tensile bond strength of different luting resin cements to different regional dentin.

    Science.gov (United States)

    Ali, Abdelraheem Mohamed; Hamouda, Ibrahim Mohamed; Ghazy, Mohamed Hamed; Abo-Madina, Manal Mohamed

    2013-03-01

    We sought to evaluate immediate and delayed micro-tensile bond strength of Panavia F2.0 and Multilink Sprint resin cement to superficial, deep and cervical dentin. Thirty-six freshly extracted non-carious human molars were sectioned in the mesiodistal direction to expose three different dentin regions including superficial dentin (1 mm below the dentine-enamel junction), deep dentin (1 mm above the highest pulp horn) and cervical dentin (0.5 mm above the cemento-enamel junction and 0.5 mm below the dentine-enamel junction). Resin cements were applied on dentin surfaces and composite blocks were luted under constant seating pressure. Each group was divided into three subgroups according to time intervals. Specimens were sectioned to obtain sticks of 1 mm(2) in diameter and subjected to microtensile bond strength testing at a cross head speed of 1 mm/min. Both resin cements showed higher micro-tensile bond strength to superficial dentin than that to deep or cervical dentin (P Micro-tensile bond strengths of Panavia F2.0 were higher than those of Multilink Sprint at different dentin regions (P micro-tensile bond strengths were higher than those of delayed micro-tensile bond strengths for both resin cements (P micro-tensile bond strengths to different dentin regions.

  6. Differences in tensile adhesion strength between HEMA and nonHEMA-based dentin bonding applied on superficial and deep dentin surfaces

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    Eresha Melati Kusuma Wurdani

    2017-03-01

    Full Text Available Background: Improvement in dentistry shows some progresses, due to patients awareness on the importance of dental care. Cervical lesion is the most common phenomenon which oftenly found 46.36% in man and 38.13% in woman. Cervical lesions need composite restoration for treatment to stop the process of tissue damage. The process of adhesion of composite restoration material to the structure of the tooth is not easily separated and it needs optimal function in the oral cavity. Application of dentin bonding agents to attach the composite is needed. Selection of HEMA-based bonding material and Hema free-based bonding material which have a different solvent in their composition, as applied to the dentin superficial and deep dentin, affect the results of debonding test. Debonding test is done to measure the adhesion strength of a bonding material. Purpose: The purpose of this study was to analyze differences in tensile bond strength of dentine bonding HEMA-based and HEMA-free based after application in superficial and deep dentine surfaces. Method: The tooth of the bovine was as samples. A superficial dentine sample was taken from 0.5-1 mm of dentino enamel junction and a deep dentine sample was taken from 0.5 mm culmination of pulp horn. Dentine surface area was equal to p x r2 = (3.14 x 22 = 12.56 mm2. Six samples of HEMA-based bonding was applied to the dentine superficial. Six samples of HEMAfree based bonding was applied to the superficial dentine. Six samples of HEMA-based bonding was applied to the deep dentine. Six samples of HEMA-free based bonding was applied to the deep dentine. Tensile strength was measured using an Autograph AG-10TE. Result: There were differences tensile bond strength of dentine bonding HEMA-based and HEMA-free based after the application on superficial (p=0.000 and deep dentine surfaces (p=0.000. Conclusion: There were differences tensile bond strength of dentine bonding HEMA-based and HEMA-free based after the

  7. Citrus pulp for cattle.

    Science.gov (United States)

    Arthington, John D; Kunkle, William E; Martin, Amy M

    2002-07-01

    Citrus pulp is classified as an energy concentrate by-product feed. Citrus by-products fed to beef cattle include citrus molasses, citrus meal, wet citrus pulp, dried citrus pulp, and pelleted citrus pulp; however, in current production systems, pulp (wet, dry, and pelleted) is the only by-product commonly used. Citrus pulp production in the United States is limited to specific subtropical regions, of which south central Florida remains the largest with additional production in California and Texas.

  8. Roles of dental pulp fibroblasts in the recognition of bacterium-related factors and subsequent development of pulpitis

    OpenAIRE

    Tadashi Nakanishi; Daisuke Takegawa; Kouji Hirao; Kanako Takahashi; Hiromichi Yumoto; Takashi Matsuo

    2011-01-01

    As caries-related bacteria invade deeply into dentin and come into close proximity to the pulp, inflammatory cells (such as lymphocytes, macrophages and neutrophils) infiltrate into the bacterium-invaded area and consequently pulpitis develops. Many types of cytokines and adhesion molecules are responsible for the initiation and progression of pulpitis. Dental pulp fibroblasts, a major cell type in the dental pulp, also have capacity to produce pro-inflammatory cytokines and express adhesion ...

  9. Dentin hypersensitivity: from diagnosis to a breakthrough therapy for everyday sensitivity relief.

    Science.gov (United States)

    Cummins, Diane

    2009-01-01

    This paper provides an overview of the current knowledge of diagnosis, epidemiology, etiology, and clinical management of dentin hypersensitivity. It summarizes technical approaches to relieve sensitivity in professional and home-use products, with emphasis on the clinical evidence for the efficacy of desensitizing toothpaste, and introduces a new innovative dentifrice technology containing 8% arginine, calcium carbonate, and 1450 ppm fluoride. Dentin hypersensitivity is characterized by short, sharp pain arising from exposed dentin in response to external stimuli which cannot be ascribed to any other form of dental defect or disease. The hydrodynamic theory proposes that pain-producing stimuli cause a change in dentin fluid flow that activates intra-dental nerve fibers, via a mechanoreceptor response, to cause pain. To be hypersensitive, dentin must be exposed and dentin tubules must be open to external stimuli and patent at the pulp. Gingival recession is the primary cause of dentin exposure, and a major predisposing factor for dentin hypersensitivity. Dentin hypersensitivity is a prevalent condition. It has been reported to afflict 15-20% of the adult population, typically 20 to 50-year-olds, with peak incidence between 30 and 39 years. Some studies have reported higher prevalence levels of up to 57%. The incidence of dentin hypersensitivity is expected to rise with changing diets, and as caries and periodontal disease prevention result in improved oral health status, and retention and functionality of the dentition. Treatments to relieve dentin hypersensitivity are based on interruption of the neural response to pain stimuli or occlusion of open tubules to block the hydrodynamic mechanism. Effective and robust dentin occlusion offers the greatest prospect for instant and lasting relief of dentin hypersensitivity. In particular, materials which can coat exposed dentin surfaces, in addition to plugging and sealing open dentin tubules, offer the intriguing

  10. 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

  11. Pulp and plaque microbiotas of children with severe early childhood caries

    Directory of Open Access Journals (Sweden)

    Natalia I. Chalmers

    2015-02-01

    Full Text Available Background and objective: Bacterial invasion into pulps of primary teeth can lead to infection and premature tooth loss in children. This pilot study aimed to explore whether the microbiota of carious exposures of dental pulps resembles that of carious dentin or that of infected root canals. Design: Children with severe early childhood caries were studied. Children were consented and extent of caries, plaque, and gingivitis measured. Bacteria were sampled from carious lesion biofilms and vital carious exposures of pulps, and processed by anaerobic culture. Isolates were characterized from partial sequences of the 16S rRNA gene and identified by comparison with taxa in the Human Oral Microbiome Database (http://www.HOMD.org. The microbiotas of carious lesions and dental pulps were compared using univariate and multivariate approaches. Results: The microbiota of cariously exposed pulps was similar in composition to that of carious lesion biofilms except that fewer species/taxa were identified from pulps. The major taxa identified belonged to the phyla Firmicutes (mainly streptococci and Actinobacteria (mainly Actinomyces species. Actinomyces and Selenomonas species were associated with carious lesions whereas Veillonella species, particularly Veillonella dispar was associated with pulps. Other bacteria detected in pulps included Streptococcus mutans, Parascardovia denticolens, Bifidobacterium longum, and several Lactobacillus and Actinomyces species. By principal, component analysis pulp microbiotas grouped together, whereas those in caries biofilms were widely dispersed. Conclusions: We conclude that the microbiota of cariously exposed vital primary pulps is composed of a subset of species associated with carious lesions. Vital primary pulps had a dominant Firmicutes and Actinobacteria microbiota which contrasts with reports of endodontic infections which can harbor a gram-negative microbiota. The microbiota of exposed primary pulps may provide

  12. Subtraction Radiographic Assessment of Underlying Dentin After Partial Carious Dentin Removal in Primary Teeth.

    Science.gov (United States)

    Phonghanyudh, Araya; Ruangdit, Chayathorn; Pornprasertsuk-D Amrongsri, Suchaya; Phanthumvanit, Prathip

    2017-09-21

    To assess the one-year outcome of glass-ionomer cement (GIC) restorations with partial carious dentin removal in primary molars using digital subtraction radiographs. Children ages 6-8 years were recruited. Forty-nine primary molars with deep carious lesions were studied. The carious dentin was removed at the dentoenamel junction (DEJ) and restored with GIC. Digital radiographs were taken immediately after restoration, and at 6 and 12 months after restoration. The sets of digital radiographs were subtracted and analysed using Image-Pro Plus software. At the 12-month follow-up, 38 of the original 49 primary molars were analysed. No postoperative pain or signs of pulp pathology were reported. 76% and 87% of molars showed an increase in density of the studied areas compared to control areas at 6- and 12- month follow-ups, respectively. The density of digital subtraction radiographs increased to 5.3 and 8.2 at 6 and 12 months from baseline, respectively. The mean density of the areas under restoration at 6 months and 12 months was statistically significantly higher than at baseline (paired t-test; p carious dentin removal in primary molars showed a high potential for dentin remineralisation after 1 year.

  13. Pulpo-dentin complex response after direct capping with self-etch adhesive systems.

    Science.gov (United States)

    Nowicka, Alicja; Parafiniuk, Miroslaw; Lipski, Mariusz; Lichota, Damian; Buczkowska-Radlinska, Jadwiga

    2012-01-01

    The purpose of the present study was to evaluate morphologically the response of feline teeth pulp to direct pulp capping with two different self-etch adhesive systems. Twenty-four cavities in feline teeth were mechanically exposed and assigned to one of two experimental groups: AdheSE + Tetric Ceram (the ASE group), or Adper Prompt L-Pop + Filtek Supreme (the APLP group). There was also a control group Dycal Ca(OH)(2) liner + Amalgam (the CH group eight teeth), and six teeth were used as an intact control group. The animals were sacrificed after 40 days. The teeth were removed and processed for standard histological evaluation, using a scoring system for inflammatory cell response, pulp tissue disorganisation, reparative tissue formation, and the presence of bacteria. Statistical analysis revealed no significant differences between the ASE and APLP self-etching resin systems during the observation period. The majority of the specimens presented inflammatory pulp response with tissue disorganisation and a lack of dentinal bridge formation. CH capping resulted in a significantly smaller inflammatory pulp response and a considerably higher incidence of reparative dentin formation. ASE and APLP were comparably effective as direct pulp capping materials, but their application resulted in significantly greater pulp tissue damage than CH capping. Further in vivo human studies are necessary to determine which adhesive resin systems should be clinically used for direct pulp capping without incurring severe damage to the pulpal tissue.

  14. In vitro reparative dentin: a biochemical and morphological study

    Directory of Open Access Journals (Sweden)

    G. Teti

    2013-08-01

    Full Text Available In this study, starting from human dental pulp cells cultured in vitro, we simulated reparative dentinogenesis using a medium supplemented with different odontogenic inductors. The differentiation of dental pulp cells in odontoblast-like cells was evaluated by means of staining, and ultramorphological, biochemical and biomolecular methods. Alizarin red staining showed mineral deposition while transmission electron microscopy revealed a  synthesis of extracellular matrix fibers during the differentiation process. Biochemical assays demonstrated that the differentiated phenotype expressed odontoblast markers, such as Dentin Matrix Protein 1 (DMP1 and Dentin Sialoprotein (DSP, as well as type I collagen. Quantitative data regarding the mRNA expression of DMP1, DSP and type I  collagen were obtained by Real Time PCR. Immunofluorescence data demonstrated the various localizations of DSP and DMP1 during odontoblast differentiation. Based on our results, we obtained odontoblast-like cells which simulated the reparative dentin processes in order to better investigate the mechanism of odontoblast differentiation, and dentin extracellular matrix deposition and mineralization. 

  15. Aetiology, classification and pathogenesis of pulp and periapical disease.

    Science.gov (United States)

    López-Marcos, Joaquín F

    2004-01-01

    At present, the majority of the treatments that are performed in the clinic are due to disease entities involving the dental pulp and periapex. Dental pulp is a richly vascularized and innervated tissue, enclosed by surrounding tissues that are incapable of expanding, such as dentin. It has terminal blood flow and small-gauge circulatory access the periapex. All of these characteristics severely constrain the defensive capacity of the pulp tissue when faced with the different aggressions it may be subjected to. Pulp tissue can also be affected by a retrograde infection, arising from the secondary canaliculi, from the periodontal ligament or from the apex during the course of periodontitis. Due to the fact that periapical disease is almost inevitably preceded by pulp disease, we shall begin by describing the causes of pulp disease and will then proceed to a discussion of the causes of periapical disease. The course of illness and classification of these pathological entities will depend on the aetiology involved. We will analyse pulp necrosis and pulp degeneration that are capable of triggering reversible apical periodontitis or irreversible apical periodontitis.

  16. Dentin sialoprotein and dentin phosphoprotein overexpression during amelogenesis.

    Science.gov (United States)

    Paine, Michael L; Luo, Wen; Wang, Hong-Jun; Bringas, Pablo; Ngan, Amanda Y W; Miklus, Vetea G; Zhu, Dan-Hong; MacDougall, Mary; White, Shane N; Snead, Malcolm L

    2005-09-09

    The gene for dentin sialophosphoprotein produces a single protein that is post-translationally modified to generate two distinct extracellular proteins: dentin sialoprotein and dentin phosphoprotein. In teeth, dentin sialophosphoprotein is expressed primarily by odontoblast cells, but is also transiently expressed by presecretory ameloblasts. Because of this expression profile it appears that dentin sialophosphoprotein contributes to the early events of amelogenesis, and in particular to those events that result in the formation of the dentino-enamel junction and the adjacent "aprismatic" enamel. Using a transgenic animal approach we have extended dentin sialoprotein or dentin phosphoprotein expression throughout the developmental stages of amelogenesis. Overexpression of dentin sialoprotein results in an increased rate of enamel mineralization, however, the enamel morphology is not significantly altered. In wild-type animals, the inclusion of dentin sialoprotein in the forming aprismatic enamel may account for its increased hardness properties, when compared with bulk enamel. In contrast, the overexpression of dentin phosphoprotein creates "pitted" and "chalky" enamel of non-uniform thickness that is more prone to wear. Disruptions to the prismatic enamel structure are also a characteristic of the dentin phosphoprotein overexpressing animals. These data support the previous suggestion that dentin sialoprotein and dentin phosphoprotein have distinct functions related to tooth formation, and that the dentino-enamel junction should be viewed as a unique transition zone between enamel and the underlying dentin. These results support the notion that the dentin proteins expressed by presecretory ameloblasts contribute to the unique properties of the dentino-enamel junction.

  17. Pulp response to Enamelite restorations in teeth of rhesus monkeys.

    Science.gov (United States)

    Amet, E M; Sayegh, F S

    1977-01-01

    The average magnitudes of cellular displacements, superficial responses, and deep responses were less for specimens restored with ZOE than for Enamelite specimens at the 1 week postoperative period. Of 20 teeth treated, three abscesses were found in the 1 week Enamelite postoperative period when the remaining dentin was 0.3 mm. or less. This indicates the presence of ingredients that are toxic to the pulp when there is little remaining dentin or when the material is placed directly over an exposure. Teeth restored with Enamelite in the 6 week group had values comparable to the ZOE teeth for the same time period.

  18. Role of laser irradiation in direct pulp capping procedures: a systematic review and meta-analysis.

    Science.gov (United States)

    Javed, Fawad; Kellesarian, Sergio Varela; Abduljabbar, Tariq; Gholamiazizi, Elham; Feng, Changyong; Aldosary, Khaled; Vohra, Fahim; Romanos, Georgios E

    2017-02-01

    A variety of materials are available to treat exposed dental pulp by direct pulp capping. The healing response of the pulp is crucial to form a dentin bridge and seal off the exposed pulp. Studies have used lasers to stimulate the exposed pulp to form tertiary dentin. The aim of the present systematic review and meta-analysis was to evaluate the evidence on the effects of laser irradiation as an adjunctive therapy to stimulate healing after pulp exposure. A systematic literature search was conducted up to April 2016. A structured search using the keywords "Direct pulp capping," "Lasers," "Calcium hydroxide pulp capping," and "Resin pulp capping" was performed. Initially, 34 potentially relevant articles were identified. After removal of duplicates and screening by title, abstract, and full text when necessary, nine studies were included. Studies were assessed for bias and data were synthetized using a random-effects meta-analysis model. Six studies were clinical, and three were preclinical animal trials; the follow-up period ranged from 2 weeks to 54 months. More than two thirds of the included studies showed that laser therapy used as an adjunct for direct pulp capping was more effective in maintaining pulp vitality than conventional therapy alone. Meta-analysis showed that the success rate in the laser treatment group was significantly higher than the control group (log odds ratio = 1.737; 95 % confidence interval, 1.304-2.171). Lasers treatment of exposed pulps can improve the outcome of direct pulp capping procedures; a number of confounding factors may have influenced the outcomes of the included studies.

  19. 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.

  20. The Dentin Tubule System: A Replica and Scanning Electron Microscope Study.

    Science.gov (United States)

    1978-06-20

    ultrason ica tor and washed for 2 addi tional 15 minute periods in distilled water. The speci- mens were then dehydrated in increasing concentrations of...branches , and the ease of penetration therein of endodontic reagents from the pulp. Intratubular network throughout the dentin may be a route of intra

  1. Direct pulp capping in an immature incisor using a new bioactive material

    Directory of Open Access Journals (Sweden)

    Sham S Bhat

    2014-01-01

    Full Text Available Preservation of the pulp in a traumatized immature fractured incisor tooth is of prime importance in order to achieve apexogenesis, a natural apical closure. The main factor influencing this is pulpal protection by a bioactive material proving optimum marginal seal in preventing any microleakage. This case report presents an 8-year-old female diagnosed with Ellis Class 3 fracture of immature tooth 11 involving the mesial pulp horn. Under rubber dam isolation, a partial pulpotomy was performed and the pulp was sealed using a new bioactive material BIODENTINE to stimulate apexogenesis, dentine replacement and pulp protection. The fractured segment was reattached for optimum esthetics, which was a concern for the patient. The patient was followed-up for 1, 3, 6 and 12 months, which revealed continued apical closure and maintenance of pulp vitality. The patient remained asymptomatic. This case report provides evidence for the potential use of Biodentine as an effective pulp capping material in the future.

  2. Identification and Isolation of Human Dental Pulp Stem Cells

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionDentinal repair in the postnatal organism occurs through the activity of specialized cells, odontoblasts, that are thought to be maintained by an as yet undefined precursor population associated with pulp tissue. Adult pulp stem cells was found in 2000. Now, it become a critical research in the world and a new stem-cells resourse for potential clinical applications. But, specific marker of DPSCs is not clear. STRO-1 was the marker that used universally. But, the expression rate was very low in...

  3. Pulp response after calcitonin treatment of direct exposures in the dog.

    Science.gov (United States)

    Cullum, D R; Kline, L W

    1985-08-01

    The hypocalcemic hormone, calcitonin, was used in directly pulp-capped teeth to determine whether or not calcitonin promoted healing. Two dogs were used. Twelve teeth received the calcitonin; nine control teeth were prepared, and five were treated with calcium hydroxide. Calcitonin did not increase either the rate of healing or the amount of secondary dentin formed. Calcitonin reduced the degree of inflammation in the treated tooth pulps.

  4. Root maturation and dentin–pulp response to enamel matrix derivative in pulpotomized permanent teeth

    OpenAIRE

    Darwish, Sherif S; Shadia H Abd El Meguid; Wahba, Nadia A; Ahmed A-R Mohamed; Wojciech Chrzanowski; Abou Neel, Ensanya A.

    2014-01-01

    The success of pulpotomy of young permanent teeth depends on the proper selection of dressing materials. This study aimed to evaluate the histological and histomorphometric response of dentin–pulp complex to the enamel matrix derivative (Emdogain® gel) compared to that of calcium hydroxide when used as a pulp dressing in immature young permanent dogs’ teeth. Dentin-like tissues bridging the full width of the coronal pu...

  5. The effects of desensitizing agents on the hydraulic conductance of human dentin in vitro.

    Science.gov (United States)

    Greenhill, J D; Pashley, D H

    1981-03-01

    The hydrodynamic theory of dentin sensitivity states that a stimulus applied at the orifice of exposed dentinal tubules causes movement of tubular fluid which stimulates nerve receptors. The fluid should obey principles of fluid movement through capillary tubes. Any decrease in the functional radius of the dentinal tubules should greatly reduce the rate of fluid flow, thus reducing dentinal sensitivity. The purpose of this study was to evaluate the ability of agents that have been used previously for clinical dentin desensitization to reduce the rate of fluid flow through dentin in vitro. Dentin discs prepared from extracted human third molars were treated with 50% citric acid to remove debris from tubular orifices. After placing the discs in a split chamber device, the rate at which buffer solution could filter across the dentin under 240 cm of water pressure was measured. The occlusal side of the disc was then treated with an agent thought to desensitize dentin to determine if it reduced fluid flow rate. Discs that had more than a 50% reduction in flow rate were examined by scanning electron microscopy to determine if those agents that decreased fluid flow also partially occluded tubular orifices. This in vitro model provided a useful quantitative method for screening a host of preparations that have been used in the past to decrease dentin sensitivity.

  6. Dentin bond strengths of simplified adhesives: effect of dentin depth.

    Science.gov (United States)

    Lopes, Guilherme Carpena; Perdigão, Jorge; Lopes, Mariana de F; Vieira, Luiz Clovis Cardoso; Baratieri, Luiz Narciso; Monteiro, Sylvio

    2006-06-01

    The objective of this study was to compare the shear bond strength of 3 simplified adhesive systems applied on shallow vs deep dentin. For superficial dentin, 30 human molars were sectioned with a diamond saw to expose dentin immediately below the dentoenamel junction. For deep dentin, 30 molars were sectioned 3 mm below the dentoenamel junction. The teeth were mounted, polished to 600-grit, and randomly assigned to 3 groups (n=10): Single Bonda and OptiBond Solo, total-etch adhesives, and Clearfil Liner Bond 2V, a self-etching primer adhesive. Adhesives were applied, the restorative material Filtek Z250 inserted in a No. 5 gelatin capsule, and light-cured. After 24 hours in water at 37 degrees C, shear bond strength was measured with an Instron at 5 mm/min. The data were analyzed with 2-way ANOVA and Duncan's post-hoc test. The results showed the following shear bond strengths (mean +/- SD in MPa): Single Bond/superficial dentin = 22.1 +/- 2.8; Single Bond/deep dentin = 14.2 +/- 7.0; OptiBond Solo/superficial dentin = 18.9 +/- 4.1; OptiBond Solo/deep dentin = 18.4 +/- 4.8; Clearfil Liner Bond 2V/superficial dentin = 21.0 +/- 7.4; Clearfil Liner Bond 2V/deep dentin = 17.6 +/- 5.9. There were no significant differences between mean shear bond strength for the factor "adhesive system" (P>.822). The Duncan's test showed that Single Bond resulted in higher shear bond strength on superficial dentin than on deep dentin. The mean shear bond strength for Clearfil Liner Bond 2V and OptiBond Solo were not influenced by dentin depth. When data were pooled for dentin depth, deep dentin resulted in statistically lower bond strengths than superficial dentin (Pcomposition of the dentin adhesive.

  7. Microbial Factors and Antimicrobial Strategies in Dental Pulp Regeneration.

    Science.gov (United States)

    Fouad, Ashraf F

    2017-09-01

    Dental pulp regeneration after pulp necrosis in immature teeth represents a major departure from traditional endodontic therapy of these conditions. Preliminary clinical attempts have shown the feasibility of developing mineralized repair tissue, which may provide a clinically acceptable outcome. However, this outcome may not provide sufficient host response and root strength to ensure the longevity of the involved teeth. It is not clear if these preliminary suboptimal results are caused by the inability to fully disinfect the pulp space or the absence of a suitable progenitor cell/scaffold template together with adequate vascularity. Moreover, it is not known to what degree the root canal system needs to be disinfected in order for clinical success to be evident. This article describes the current clinical strategies and protocols for the optimal disinfection and preparation of the pulp space environment to promote periapical healing as well as soft and hard tissue development after an infectious process. Current and future strategies for disinfecting the pulp space with minimal disruption of the necessary biological factors from dentin, the progenitor cells in periapical vital tissues, and the vascularity are discussed. The potential for success of pulp regeneration after necrosis and infection would transform the practice of endodontics, even for mature teeth. This is a goal worth pursuing because it would achieve the restoration of normal host responses in the pulp space and the regeneration of destroyed dental tissues. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Possible mechanisms of lack of dentin bridge formation in response to calcium hydroxide in primary teeth

    Directory of Open Access Journals (Sweden)

    G R Ravi

    2015-01-01

    Full Text Available Introduction: The usage of Calcium hydroxide (CaOH2 has wide applications due to the property of osteo-inductive, protective, and antibacterial actions. However, it is not used in primary teeth, as it fails to form reparative dentin and the exact mechanism has not been explained. The hypothesis: The authors propose an explanation that lack of dentin bridge formation in response to (CaOH2 in primary teeth could be multifactorial: inability of the deciduous stem cells to generate complete dentin-pulp-like tissue; the absence of calcium-magnesium-dependent adenosine triphosphatase (Ca-Mg ATPase in the odontoblasts; the pre-existing predilection of deciduous dentine pulp to form odontoclasts; the solubility of (CaOH2. Evaluation of the hypothesis: The hypothesis discusses the innate traits of the deciduous stem cells that lack the ability to form the dentin bridge, the absence of Ca-Mg ATPase enzyme and increased solubility of (CaOH2 together fail to stimulate the odontoblasts. Alternatively, pre-existing progenitor cells with proclivity to change into odontoclasts may cause internal resorption and hamper formation of reparative dentin.

  9. Regenerative medicine in dental and oral tissues: Dental pulp mesenchymal stem cell

    Directory of Open Access Journals (Sweden)

    Janti Sudiono

    2017-08-01

    Full Text Available Background. Regenerative medicine is a new therapeutic modality using cell, stem cell and tissue engineering technologies. Purpose. To describe the regenerative capacity of dental pulp mesenchymal stem cell. Review. In dentistry, stem cell and tissue engineering technologies develop incredibly and attract great interest, due to the capacity to facilitate innovation in dental material and regeneration of dental and oral tissues. Mesenchymal stem cells derived from dental pulp, periodontal ligament and dental follicle, can be isolated, cultured and differentiated into various cells, so that can be useful for regeneration of dental, nerves, periodontal and bone tissues. Tissue engineering is a technology in reconstructive biology, which utilizes mechanical, cellular, or biological mediators to facilitate regeneration or reconstruction of a particular tissue. The multipotency, high proliferation rates and accessibility, make dental pulp as an attractive source of mesenchymal stem cells for tissue regeneration. Revitalized dental pulp and continued root development is the focus of regenerative endodontic while biological techniques that can restore lost alveolar bone, periodontal ligament, and root cementum is the focus of regenerative periodontic. Conclucion. Dentin-derived morphogens such as BMP are known to be involved in the regulation of odontogenesis. The multipotency and angiogenic capacity of DPSCs as the regenerative capacity of human dentin / pulp complex indicated that dental pulp may contain progenitors that are responsible for dentin repair. The human periodontal ligament is a viable alternative source for possible primitive precursors to be used in stem cell therapy.

  10. Preliminary study on dental pulp stem cell-mediated pulp regeneration in canine immature permanent teeth.

    Science.gov (United States)

    Wang, Yuanyuan; Zhao, Yuming; Jia, Weiqian; Yang, Jie; Ge, Lihong

    2013-02-01

    The health of human teeth depends on the integrity of the hard tissue and the activity of the pulp and periodontal tissues, which are responsible for nutritional supply. Without the nourishing of the pulp tissue, the possibility of tooth fracture can increase. In immature permanent teeth, root development may be influenced as well. This study explored the potential of using autologous dental pulp stem cells (DPSCs) to achieve pulp regeneration in a canine pulpless model. The establishment of the pulpless animal model involved pulp extirpation and root canal preparation of young permanent incisor teeth in beagles. Autologous DPSCs were obtained from extracted first molars and expanded ex vivo to obtain a larger number of cells. The biological characteristics of canine DPSCs (cDPSCs) were analyzed both in vitro and in vivo by using the same method as used in human DPSCs. cDPSCs were transplanted into the pulpless root canal with Gelfoam as the scaffold, and root development was evaluated by radiographic and histologic analyses. cDPSCs with rapid proliferation, multiple differentiation capacity, and development potential were successfully isolated and identified both in vitro and in vivo. After they were transplanted into the pulpless root canal with Gelfoam as the scaffold, DPSCs were capable of generating pulp-like tissues containing blood vessels and dentin-like tissue. Thickening of the root canal wall was also observed. This study demonstrates the feasibility of using stem cell-mediated tissue engineering to realize pulp regeneration in immature teeth. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Mobilized dental pulp stem cells for pulp regeneration: initiation of clinical trial.

    Science.gov (United States)

    Nakashima, Misako; Iohara, Koichiro

    2014-04-01

    Stem cell therapy is a potential strategy to regenerate the dentin-pulp complex, enabling the conservation and restoration of functional teeth. We assessed the efficacy and safety of pulp stem cell transplantation as a prelude before the initiation of clinical trials. Granulocyte-colony stimulating factor (G-CSF) induces subsets of dental pulp stem cells to form mobilized dental pulp stem cells (MDPSCs). Good manufacturing practice is a prerequisite for the isolation and expansion of MDPSCs that are enriched in stem cells, expressing a high level of trophic factors with properties of high proliferation, migration, and antiapoptotic effects and endowed with regenerative potential. The quality of clinical-grade MDPSCs was assured by the absence of abnormalities/aberrations in karyotype and the lack of tumor formation after transplantation in immunodeficient mice. Autologous transplantation of MDPSCs with G-CSF in pulpectomized teeth in dogs augmented the regeneration of pulp tissue. The combinatorial trophic effects of MDPSCs and G-CSF on cell migration, antiapoptosis, immunosuppression, and neurite outgrowth were also confirmed in vitro. Furthermore, MDPSCs from the aged donors were as potent as the young donors. It is noteworthy that there were no significant age-related changes in biological properties such as stability, regenerative potential, and expression of the senescence markers in MDPSCs. On the other hand, autologous transplantation of MDPSCs with G-CSF induced less regenerated pulp tissue in the aged dogs compared with the young dogs. In conclusion, the preclinical safety, feasibility, and efficacy of pulp regeneration by MDPSCs and G-CSF were established. Therefore, the standardization and establishment of regulatory guidelines for stem cell therapy in clinical endodontics is now a reality. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Scaffold-free Prevascularized Microtissue Spheroids for Pulp Regeneration.

    Science.gov (United States)

    Dissanayaka, W L; Zhu, L; Hargreaves, K M; Jin, L; Zhang, C

    2014-12-01

    Creating an optimal microenvironment that mimics the extracellular matrix (ECM) of natural pulp and securing an adequate blood supply for the survival of cell transplants are major hurdles that need to be overcome in dental pulp regeneration. However, many currently available scaffolds fail to mimic essential functions of natural ECM. The present study investigated a novel approach involving the use of scaffold-free microtissue spheroids of dental pulp stem cells (DPSCs) prevascularized by human umbilical vein endothelial cells (HUVECs) in pulp regeneration. In vitro-fabricated microtissue spheroids were inserted into the canal space of tooth-root slices and were implanted subcutaneously into immunodeficient mice. Histological examination revealed that, after four-week implantation, tooth-root slices containing microtissue spheroids resulted in well-vascularized and cellular pulp-like tissues, compared with empty tooth-root slices, which were filled with only subcutaneous fat tissue. Immunohistochemical staining indicated that the tissue found in the tooth-root slices was of human origin, as characterized by the expression of human mitochondria, and contained odontoblast-like cells organized along the dentin, as assessed by immunostaining for nestin and dentin sialoprotein (DSP). Vascular structures formed by HUVECs in vitro were successfully anastomosed with the host vasculature upon transplantation in vivo, as shown by immunostaining for human CD31. Collectively, these findings demonstrate that prevascularized, scaffold-free, microtissue spheroids can successfully regenerate vascular dental pulp-like tissue and also highlight the significance of the microtissue microenvironment as an optimal environment for successful pulp-regeneration strategies. © International & American Associations for Dental Research.

  13. Effect of IRM on human dental pulp.

    Science.gov (United States)

    Möller, B; Schröder, U; Granath, L

    1983-08-01

    IRM has been shown to be superior to conventional ZnOE cements. This study is a biotechnical investigation of IRM's effect on the dental pulp with respect to its sealing capacity. Enamel-dentin test bodies with IRM fillings were used in the in vitro part, where insufficiencies in sealing were detected with compressed air. The in vivo part included 44 buccal cavities in intact premolars. In teeth in which the material effect of IRM was tested, the IRM fillings were sealed off from the saliva by acid etch and composite resin. The observation intervals were 1, 7 and 28 days. Histologic changes such as capillary dilatations and presence of inflammatory cells in the pulp adjacent to the dentinal tubules involved in the cavity preparation were registered. The in vitro test showed no leakage in five cases out of six. After extreme temperature cycling, the leakage was comparable with that of zinc-containing amalgam of traditional alloy. The pulpal changes were mild and mainly ascribed to the material effect of IRM, since no evidence was found of leakage of biologic importance.

  14. C-myb Regulates Autophagy for Pulp Vitality in Glucose Oxidative Stress.

    Science.gov (United States)

    Lee, Y H; Kim, H S; Kim, J S; Yu, M K; Cho, S D; Jeon, J G; Yi, H K

    2016-04-01

    Diabetes mellitus is closely related to oral-complicated diseases by oxidative stress. This study investigates whether cellular myeloblastosis (c-myb) could protect human dental pulp cells against glucose oxidative stress and regulate autophagy activity for pulp vitality. Diabetes mellitus was induced by streptozotocin in Sprague-Dawley rats, and their pulp tissue in teeth was analyzed in terms of pulp cavity and molecules by hematoxylin and eosin and immunohistochemistry staining. Human dental pulp cells were serially subcultured and treated with glucose oxidase in the presence of elevated glucose to generate glucose oxidative stress. The replication-deficient adenovirus c-myb and small interfering RNA c-myb were introduced for c-myb expression. The pulp tissue from the diabetic rats was structurally different from normal tissue in terms of narrow pulp capacity, reduced c-myb, and dentinogenesis molecules. Glucose oxidase treatment decreased c-myb and dentinogenesis molecules (bone morphogenetic protein 2 and 7, dentin matrix protein 1, and dentin sialophosphoprotein) in human dental pulp cells. However, overexpression of c-myb by adenovirus c-myb increased dentinogenesis, autophagy molecules (autophagy protein 5, microtubule-associated protein 1A/1B-light chain 3, and Beclin-1), and cell survival via p-AMPK/AKT signaling even with glucose oxidative stress. In contrast, the lack of c-myb decreased the above molecules and cell survival by downregulating p-AMPK/AKT signaling. The results indicate that diabetes leads to irreversible damage to dental pulp, which is related to downexpression of autophagy via the p-AMPK/AKT pathway by decline of c-myb. The findings of this study provide a new insight that c-myb could ameliorate autophagy activity and that it is applicable for monitoring complicated diseases of dental pulp. The involvement of c-myb in pulp pathology could serve a therapeutic target in oral-complicated diseases.

  15. Evaluation of primary carious dentin after cavity sealing in deep lesions: a 10- to 13-month follow-up.

    Science.gov (United States)

    Chibinski, Ana Claudia R; Reis, Alessandra; Kreich, Eliane Maria; Tanaka, Jefferson Luis O; Wambier, Denise S

    2013-01-01

    This study's purpose was to describe the primary dentin reactions following restoration without complete removal of infected dentin. Fragments of carious dentin from 43 teeth with acute deep lesions were removed at baseline and compared to samples of carious dentin removed 60 days later, using scanning electron microscopy (SEM) photographs. At the follow-up periods (60 days; 10-13 months), restorations were evaluated using US Public Health Service criteria and standardized radiographs. A postprocessing routine of radiographs was used to identify changes in radiographic density between periods. At baseline, SEM photographs showed disorganized tissue and bacterial invasion. After 60 days, the dentin exhibited a better organization and signs of remineralization. Differences in restoration characteristics were detected for cavosurface discoloration (P=.008), wear (Pcarious and sound dentin increased after 10 to 13 months (Pcarious and sound dentin only for the 60-day images (P=.03). Removal of infected dentin wasn't fundamental for caries arrestment. Carious dentin tended to reorganize in a short period when properly sealed, and the remineralization process continued for longer periods. Correct diagnosis of pulp vitality seems fundamental for the success of this protocol.

  16. REINFORCING POTENTIAL OF JUTE PULP WITH TREMA ORIENTALIS (NALITA) PULP

    OpenAIRE

    Sabina Rawshan; M. Sarwar Jahan

    2009-01-01

    Two morphologically different pulps, a long-fiber jute pulp from a soda-AQ process and a short-fiber Trema orientalis pulp from a kraft process, were evaluated and compared for their reinforcing potential. T. orientalis pulp needed less beating energy than jute pulp at the same drainage resistance. Addition of jute fiber pulp to the T. orientalis pulp increased tear strength. Sheet density of pulp blends was increased with the increase of beating degree of both pulps and the proportion of T. ...

  17. Cigarette smoke affects bonding to dentin.

    Science.gov (United States)

    Almeida e Silva, Junio S; de Araujo, Edson Medeiro; Araujo, Elito

    2010-01-01

    This in vitro study evaluated the microtensile bond strength (muTBS) of composite resin bonded to dentin that had been contaminated by cigarette smoke. Ten extracted unerupted human third molars were used: Six molars were prepared for muTBS testing, while the other four molars were assigned to pre- and post-etching scanning electronic microscopy (SEM) analysis. The 20 specimens obtained from the 10 coronal portions were distributed into two experimental groups so that each tooth served as its own control. Group 1 underwent a daily toothbrushing simulation and exposure to a smoking simulation chamber, while Group 2 received only a daily simulated toothbrushing. Student's t-test demonstrated that Group 1 samples demonstrated significantly lower bond strength (49.58 MPa) than Group 2 samples (58.48 MPa). Pre and postetching SEM analysis revealed the presence of contaminants on the dentinal surfaces of the Group 1 specimens. It was concluded that contamination by cigarette smoke decreases the bond strength between dentin and composite resin.

  18. Clinical evaluation of mineral trioxide aggregate and biodentine as direct pulp capping agents in carious teeth.

    Science.gov (United States)

    Hegde, Swaroop; Sowmya, B; Mathew, Sylvia; Bhandi, Shilpa H; Nagaraja, Shruthi; Dinesh, K

    2017-01-01

    Root canal treatment has been a routine treatment option for carious exposure of the dental pulp. In the context of minimally invasive dentistry, direct pulp capping (DPC) procedure with a reliable biomaterial may be considered as an alternative provided the pulp status is favorable. Mineral trioxide aggregate (MTA), a bioactive cement with excellent sealing ability and biocompatibility is capable of regenerating relatively damaged pulp and formation of dentin bridge when used as DPC agent. Biodentine is comparatively a new biomaterial claimed to possess properties similar to MTA and is currently explored for vital pulp therapy procedures. The aim of the present study was to evaluate the clinical response of pulp-dentin complex after DPC with MTA and biodentine in carious teeth. Twenty-four permanent molars with carious exposure having no signs and symptoms of irreversible pulpitis were selected and assigned to one of the two groups, Group I - MTA and Group II - biodentine. Patients were recalled at 3 weeks, 3 months, and 6 months for clinical and radiographic evaluation. Fisher's exact test was used along with Chi-square test for statistical analysis. Over a period of 6 months, MTA and biodentine showed 91.7% and 83.3% success rate, respectively, based on the subjective symptoms, pulp sensibility tests, and radiographic appearance. MTA and biodentine may be used as DPC agents when the pulpal diagnosis is not more than reversible pulpitis.

  19. Indirect pulp therapy: an alternative to pulpotomy in primary teeth.

    Science.gov (United States)

    Seale, N Sue

    2010-11-01

    Preservation of the primary teeth until their normal exfoliation is essential for normal oral function and facial growth of the child. To that end, treatment of primary teeth with large carious lesions approximating the pulp should be aimed at preserving the tooth. Currently, the pulpotomy is the most frequently used pulp treatment for cariously involved primary teeth. The purpose of this manuscript is to describe the use of an alternative to the pulpotomy, indirect pulp therapy (IPT), for the treatment of vital, primary teeth with carious involvement approaching the pulp. Accurate diagnosis of the vitality status of the pulp is critical to the success of IPT and involves careful radiographic and clinical assessment of the teeth to be sure they are healthy or at worst, reversibly inflamed. The indications for IPT are the same as for pulpotomy. The technique involves one appointment, requires that some carious dentin be left to avoid pulp exposure and requires the placement of a biologically sealing base and sealing final restoration. Teeth treated with IPT have success rates at least as good as those treated with pulpotomies, and IPT offers an acceptable alternative to pulpotomy as a treatment for vital, asymptomatic, cariously involved primary teeth.

  20. Advanced Scaffolds for Dental Pulp and Periodontal Regeneration.

    Science.gov (United States)

    Bottino, Marco C; Pankajakshan, Divya; Nör, Jacques E

    2017-10-01

    No current therapy promotes root canal disinfection and regeneration of the pulp-dentin complex in cases of pulp necrosis. Antibiotic pastes used to eradicate canal infection negatively affect stem cell survival. Three-dimensional easy-to-fit antibiotic-eluting nanofibers, combined with injectable scaffolds, enriched or not with stem cells and/or growth factors, may increase the likelihood of achieving predictable dental pulp regeneration. Periodontitis is an aggressive disease that impairs the integrity of tooth-supporting structures and may lead to tooth loss. The latest advances in membrane biomodification to endow needed functionalities and technologies to engineer patient-specific membranes/constructs to amplify periodontal regeneration are presented. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. The inhibition effect of non-protein thiols on dentinal matrix metalloproteinase activity and HEMA cytotoxicity.

    Science.gov (United States)

    Nassar, Mohannad; Hiraishi, Noriko; Shimokawa, Hitoyata; Tamura, Yukihiko; Otsuki, Masayuki; Kasugai, Shohei; Ohya, Keiichi; Tagami, Junji

    2014-03-01

    Phosphoric acid (PA) etching used in etch-and-rinse adhesives is known to activate host-derived dentinal matrix-metalloproteinases (MMPs) and increase dentinal permeability. These two phenomena will result, respectively; in degradation of dentine-adhesive bond and leaching of some monomers especially 2-hydroxyethyl methacrylate (HEMA) into the pulp that would negatively affect the viability of pulpal cells. This study is the first to investigate the inhibitory effect of non-protein thiols (NPSH); namely reduced glutathione (GSH) and N-acetylcysteine (NAC) on dentinal MMPs and compare their effects on HEMA cytotoxicity. Dentine powder was prepared from human teeth, demineralized with 1% PA and then treated with 2% GSH, 2% NAC or 2% chlorhexidine (CHX). Zymographic analysis of extracted proteins was performed. To evaluate the effect of GSH, NAC and CHX on HEMA cytotoxicity, solutions of these compounds were prepared with or without HEMA and rat pulpal cells were treated with the tested solutions for (6 and 24h). Cells viability was measured by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cytotoxicity data were analysed by one-way ANOVA and Tukey post hoc tests (pcytotoxicity inhibition. NPSH were effective to inhibit dentinal MMPs and HEMA cytotoxicity. The tested properties of NPSH provide promising clinical use of these agents which would enhance dentine-bond durability and decrease post-operative sensitivity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Phenotypic variation in dentinogenesis imperfecta/dentin dysplasia linked to 4q21.

    Science.gov (United States)

    Beattie, M L; Kim, J-W; Gong, S-G; Murdoch-Kinch, C A; Simmer, J P; Hu, J C-C

    2006-04-01

    Dentinogenesis imperfecta (DGI) and dentin dysplasia (DD) are allelic disorders that primarily affect the formation of tooth dentin. Both conditions are autosomal-dominant and can be caused by mutations in the dentin sialophosphoprotein gene (DSPP, 4q21.3). We recruited 23 members of a four-generation kindred, including ten persons with dentin defects, and tested the hypothesis that these defects are linked to DSPP. The primary dentition showed amber discoloration, pulp obliteration, and severe attrition. The secondary dentition showed either pulp obliteration with bulbous crowns and gray discoloration or thistle-tube pulp configurations, normal crowns, and mild gray discoloration. Haplotype analyses showed no recombination between three 4q21-q24 markers and the disease locus. Mutational analyses identified no coding or intron junction sequence variations associated with affection status in DMP1, MEPE, or the DSP portion of DSPP. The defects in the permanent dentition were typically mild and consistent with a diagnosis of DD-II, but some dental features associated with DGI-II were also present. We conclude that DD-II and DGI-II are milder and more severe forms, respectively, of the same disease.

  3. Performance of electrospun poly(ε-caprolactone) fiber meshes used with mineral trioxide aggregates in a pulp capping procedure.

    Science.gov (United States)

    Lee, WooCheol; Oh, Joung-Hwan; Park, Joo-Cheol; Shin, Hong-In; Baek, Jeong-Hwa; Ryoo, Hyun-Mo; Woo, Kyung Mi

    2012-08-01

    Living dental pulp tissue exposed to the oral environment should be protected with an appropriate pulp capping material to support the dentinogenesis potential of the pulp cells. Mineral trioxide aggregate (MTA) is the material of choice for the treatment of pulp. However, due to cytotoxicity during the initial setting phase of MTA, a new material is required that can act as a barrier to direct contact but facilitate the favorable effect of MTA. This study examined the feasibility of using electrospun poly(ε-caprolactone) fiber (PCL-F) meshes in the MTA-based pulp capping procedures. An experimental pulp capping was performed on the premolars of beagle dogs, and the efficacy of the PCL-F meshes was evaluated after 8 weeks. PCL-F/MTA formed a dentin bridge that was approximately fourfold thicker than that formed by the MTA. Columnar polarized odontoblast-like cells with long processes and tubular dentin-like matrices were observed beneath the dentin bridge in the PCL-F/MTA. The cells were also intensely immunostained for dentin sialoprotein. In cell cultures, PCL-F/MTA reduced cell death to ~8% of that in the MTA group. The proliferation of the cells cultured on PCL-F/MTA was much greater than that of cells cultured on MTA. Furthermore, PCL-F/MTA promoted the differentiation of MDPC23 cells to odontoblast-like cells and biomineralization, as confirmed by the expression of alkaline phosphatase and dentin sialophosphoprotein, and by the deposition of calcium. Based on these histologic findings and the cell responses observed in this study, PCL-F may be used efficiently in the MTA-based dental pulp therapy.

  4. Role of CTGF/CCN2 in reparative dentinogenesis in human dental pulp.

    Science.gov (United States)

    Muromachi, Koichiro; Kamio, Naoto; Matsumoto, Takashi; Matsushima, Kiyoshi

    2012-03-01

    Connective tissue growth factor/CCN family 2 (CTGF/CCN2) has been considered to participate in tooth development. To date, the expression and role of CTGF/CCN2 in reparative dentinogenesis have been unclear. Our previous study revealed that matrix metalloproteinase-3 (MMP-3) stimulates cell migration via CTGF/CCN2 expression and secretion in human dental pulp cells, and that this is dependent on dynamin-related endocytosis and independent of protease activity. The objective of the present study was to determine the expression of CTGF/CCN2 in reparative dentin in human carious teeth and to examine the effect of CTGF/CCN2 on mineralization in cultured human dental pulp cells. Minimal expression of CTGF/CCN2 was evident in odontoblasts subjacent to the dentin-pulp junction in healthy teeth, whereas strong expression was detected in odontoblast-like cells lining the reparative dentin subjacent to dental caries. In human dental pulp cells, CTGF/CCN2 promoted mineralization but failed to induce proliferation, suggesting that this molecule has the ability to induce the differentiation of human dental pulp cells. Taken together, the data suggest that CTGF/CCN2 is likely involved in reparative dentinogenesis through formation of hard tissue in human carious teeth.

  5. Apoptosis Activation in Human Carious Dentin. An Immunohistochemical Study

    Science.gov (United States)

    Loreto, C.; Psaila, A.; Musumeci, G.; Castorina, S.; Leonardi, R.

    2015-01-01

    The exact mechanisms and enzymes involved in caries progression are largely unclear. Apoptosis plays a key role in dentin remodelling related to damage repair; however, it is unclear whether apoptosis in decayed teeth is activated through the extrinsic or the intrinsic pathway. This ex vivo immunohistochemical study explored the localization of TRAIL, DR5, Bcl-2 and Bax, the main proteins involved in apoptosis, in teeth with advanced caries. To evaluate TRAIL, DR5, Bcl-2 and Bax immunoexpressions twelve permanent carious premolars were embedded in paraffin and processed for immunohistochemistry. The results showed that TRAIL and DR5 were overexpressed in dentin and in pulp vessels and mononuclear cells; strong Bax immunostaining was detected in dilated dentinal tubules close to the lesion, and Bcl-2 staining was weak in some dentin areas under the cavity or altogether absent. These findings suggest that both apoptosis pathways are activated in dental caries. Further studies are required to gain insights into its biomolecular mechanisms. PMID:26428882

  6. Side population cells isolated from porcine dental pulp tissue with self-renewal and multipotency for dentinogenesis, chondrogenesis, adipogenesis, and neurogenesis.

    Science.gov (United States)

    Iohara, Koichiro; Zheng, Li; Ito, Masataka; Tomokiyo, Atsushi; Matsushita, Kenji; Nakashima, Misako

    2006-11-01

    Dental pulp has the potential to form dentin as a regenerative response to caries. This regeneration is mediated by stem/progenitor cells. Thus, stem cell therapy might be of potential utility in induction of reparative dentin. We isolated side population (SP) cells from dental pulp based on the exclusion of the DNA binding dye Hoechst 33342 by flow cytometry and compared its self-renewal capacities and multipotency with non-SP cells and primary pulp cells. The cumulative cell number of the SP cells was greater than the non-SP cells and primary pulp cells. Bmi1 was continuously expressed in SP cells, suggesting longer proliferative lifespan and self-renewal capacity of SP cells. Next, the maintenance of the multilineage differentiation potential of pulp SP cells was investigated. Expression of type II collagen and aggrecan confirmed chondrogenic conversion (30%) of SP cells. SP cells expressed peroxisome proliferator-activated receptor gamma and adaptor protein 2, showing adipogenic conversion. Expression of mRNA and proteins of neurofilament and neuromodulin confirmed neurogenic conversion (90%). These results demonstrate that pulp SP cells maintain multilineage differentiation potential. We further examined whether bone morphogenetic protein 2 (BMP2) could induce differentiation of pulp SP cells into odontoblasts. BMP2 stimulated the expression of dentin sialophosphoprotein (Dspp) and enamelysin in three-dimensional pellet cultures. Autogenous transplantation of the Bmp2-supplemented SP cells on the amputated pulp stimulated the reparative dentin formation. Thus, adult pulp contains SP cells, which are enriched for stem cell properties and useful for cell therapy with BMP2 for dentin regeneration.

  7. Histopathologic study on pulp response to single-bottle and self-etching adhesive systems.

    Science.gov (United States)

    Medina, Vicente O; Shinkai, Koichi; Shirono, Manabu; Tanaka, Norihiro; Katoh, Yoshiroh

    2002-01-01

    This study compared the pulp response to seven adhesive resins (three single-bottle and four self-etching primers) and their companion resin composite systems with a commercial calcium hydroxide material when applied to exposed monkey pulps. The control group was capped with Dycal (DY), while the experimental groups were capped with one of the following adhesive resin systems: AQ Bond (AQ), Single Bond (SB), Imperva Fluorobond (IF), One Step (OS), Prime&Bond NT (PBNT), Perme Bond F (PBF) and One-up Bond F (OBF). Histopathologic evaluation of pulp tissue disorganization, inflammatory cell infiltration, reparative dentin formation and bacterial penetration at the 3rd, 30th and 90th post-operative days was done using light microscopy. Data were analyzed using the Kruskal-Wallis test followed by the Least Significant Difference Test to determine differences between the control group and the experimental groups at each observation period. The correlation of inflammatory cell infiltration and bacterial presence was investigated by the Kendall correlation analysis. All tests were performed at a 95% level of confidence. The pulpal responses of groups DY, SB, OS, PBF and OBF were generally characterized by none-to-mild pulp tissue disorganization and inflammatory cell infiltration. Also, initiation of reparative dentin formation was found earlier in Group DY, resulting in more complete dentin bridges at the 30- and 90-day observation periods. Groups AQ, IF and PBNT had significantly more inflammatory cell infiltration and a lower incidence of reparative dentin formation than Group DY. A significant correlation was detected between inflammatory cell infiltration and the presence of bacteria. It is concluded that the pulp response to SB, OS, PBF and OBF is not significantly different from the calcium hydroxide preparation. However, calcium hydroxide capping resulted in a higher incidence and faster rate of reparative dentin formation.

  8. Hyperlipidemia induced by high-fat diet enhances dentin formation and delays dentin mineralization in mouse incisor.

    Science.gov (United States)

    Ye, Xin; Zhang, Jin; Yang, Pishan

    2016-10-01

    Dyslipidemia has become a serious health problem in children and adolescents worldwide for its high prevalence. Since hard tissues of permanent teeth form mainly during this period and lipids are actively involved in tooth development, the effects of hyperlipidemia on dental tissue formation and mineralization need to be illustrated. In this study, hyperlipidemia model was established in mice fed with high-fat diet (HFD). Micro-CT and histomorphological analyses were performed on the mandibular bones to assess the morphological changes of the mandibular incisor and first molar. After 4 weeks of HFD feeding, mice had significantly elevated serum lipid levels compared with mice fed with control diet. After 8 weeks, the mandibular incisor presented significantly increased dentin thickness and decreased diameter of pulp cavity in HFD-fed mice compared with control diet-fed mice, while its gross morphology and enamel thickness were not altered. In the mandibular first molar, dentin thickness of root did not show difference between the two groups. Histological section showed that mandibular incisor of HFD-fed mice manifested a wider predentin region and a lower mineral apposition rate compared with that of the control mice. In conclusion, hyperlipidemia induced by HFD feeding enhances dentin formation and delays dentin mineralization in the developing mouse incisor.

  9. spark chamber

    CERN Multimedia

    A few cosmic rays pass through your body every second of every day, no matter where you are. Look at the spark chamber to your right – every flash is the track made by a cosmic ray from outer space. The spark chamber is filled with a special gas mixture. Cosmic rays knock electrons out of the atoms in the gas. These electrons accelerate towards high voltage metal strips layered throughout the chamber, creating sparks like little bolts of lightning.

  10. spark chamber

    CERN Multimedia

    A few cosmic rays pass through your body every second of every day, no matter where you are. Look at the spark chamber to your right – every flash is the track made by a cosmic ray from outer space. The spark chamber is filled with a special gas mixture. Cosmic rays knock electrons out of the atoms in the gas. These electrons accelerate towards high voltage metal strips layered throughout the chamber, creating sparks like little bolts of lightning.

  11. Dental Pulp Testing: A Review

    OpenAIRE

    Eugene Chen; Abbott, Paul V

    2009-01-01

    Dental pulp testing is a useful and essential diagnostic aid in endodontics. Pulp sensibility tests include thermal and electric tests, which extrapolate pulp health from sensory response. Whilst pulp sensibility tests are the most commonly used in clinical practice, they are not without limitations and shortcomings. Pulp vitality tests attempt to examine the presence of pulp blood flow, as this is viewed as a better measure of true health than sensibility. Laser Doppler flowmetry and pulse o...

  12. Dentin sensitivity, odontoblasts and nerves under desiccated or infected experimental cavities. A clinical, light microscopic and ultrastructural investigation.

    Science.gov (United States)

    Lilja, J; Nordenvall, K J; Bränström, M

    1982-01-01

    Cavities were prepared in 35 pairs of young human premolars. One tooth in each pair served as a control. In one Series the test cavity was desiccated with compressed air for one minute. LM and TEM examination of the dentin and the adjacent pulp revealed an extensive aspiration of odontoblasts. Nerve fibers had moved 0.1 to 0.2 mm outward in the tubules. It is suggested that a streching or disruption of the nerve had occurred during desiccation. In a second Series, the test cavity was infected for 1 to 2 weeks. No nerve fibers were seen in the dentinal tubules under the cavities, only cellular remnants and some microorganisms. Despite the absence of nerves the dentin in the bottom of the infected cavities was highly sensitive to stimulation. It was concluded that the nociceptive nerves present in the adjacent inflamed pulp may be terminals, mechanosensitive in nature and that they activated by rapid outward movements of the tubules fluid.

  13. 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.

  14. Differences in the Microstructure and Fatigue Properties of Dentin Between Residents of North and South America

    Science.gov (United States)

    Ivancik, J.; Naranjo, M.; Correa, S.; Ossa, A.; Tay, F.R.; Pashley, D.H.; Arola, D.

    2014-01-01

    Spatial variations in the microstructure of dentin contribute to its mechanical behavior. Objective The objective of this investigation was to compare the microstructure and fatigue behavior of dentin from donors of two different countries. Methods Caries-free third molars were obtained from dental practices in Colombia, South America and the US to assemble two age-matched samples. The microstructure of the coronal dentin was evaluated at three characteristic depths (i.e. deep, middle and superficial dentin) using scanning electron microscopy and image processing techniques. The mechanical behavior of dentin in these three regions was evaluated by the fatigue crack growth resistance. Cyclic crack growth was achieved in-plane with the dentin tubules and the fatigue crack growth behavior was characterized in terms of the stress intensity threshold and the Paris Law parameters. Results There was no difference in the tubule density between the dentin of patients from the two countries. However, there were significant differences (p≤0.05) in the tubule lumen diameters between the two groups in the deep and peripheral regions. In regards to the fatigue resistance, there was a significant increase (p≤0.05) in threshold stress intensity range, and a significant decrease in fatigue crack growth coefficient with increasing distance from the pulp in teeth from the US donors. In contrast, these properties were independent of location for the dentin of teeth from the Colombian donors. Conclusions The microstructure of dentin and its mechanical behavior appear to be a function of patient background, which may include environmental factors and/or ethnicity. PMID:24960115

  15. Concentrations of trace element in human dentin by sex and age.

    Science.gov (United States)

    Kumagai, Akiko; Fujita, Yuji; Endo, Shigeatsu; Itai, Kazuyoshi

    2012-06-10

    Teeth are recently drawing attention for their potential as biological modeling investigation samples due to their ability to be collected and their slow substance metabolism. There is no active metabolism of elements after the completion of dentin. Dentin is surrounded by enamel and cementum, and is not affected by the oral environment. Therefore, the amount of trace elements in dentin may change with age, and this is considered to be a reliable biological load index. The objectives in this study are to demonstrate concentrations of elements in the dentin of healthy Japanese subjects by sex and age, and to reveal the relationship between element levels and age. 121 healthy teeth samples were extracted due to periodontal disease or orthodontic treatment. Each tooth was sliced from the crown to the root apex into 0.5-1mm thickness, then enamel, cementum, and the pulp were removed; the dentins were used as samples. The concentration of 10 trace elements (B, Mn, Co, Cu, Zn, Rb, Sr, Mo, Cd, and Pb) in the dentin was measured using inductively coupled plasma mass spectrometer (ICP-MS). The differences Co and Pb in the dentin between men and women were significant (p<0.01). Significant positive correlation was observed between B, Co, Cu, Zn, Sr and Pb concentrations in the dentin and age (p<0.001). The results of the present study suggest that human dentin is an appropriate substance for relativity with sex and age at further future research. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. Rescue of Odontogenesis in Dmp1-deficient Mice by Targeted Re-expression of DMP1 Reveals Roles for DMP1 in Early Odontogenesis and Dentin Apposition in vivo

    OpenAIRE

    Lu, Yongbo; Ye, Ling; Yu, Shibin; Zhang, Shubin; Xie, Yixia; McKee, Marc D.; Li, Yan Chun; Kong, Juan; Eick, J. David; Dallas, Sarah L.; Feng, Jian Q.

    2006-01-01

    Dentin matrix protein 1 (DMP1) is expressed in both pulp and odontoblast cells and deletion of the Dmp1 gene leads to defects in odontogenesis and mineralization. The goals of this study were to examine how DMP1 controls dentin mineralization and odontogenesis in vivo. Fluorochrome labeling of dentin in Dmp1-null mice showed a diffuse labeling pattern with a three-fold reduction in dentin appositional rate compared to controls. Deletion of DMP1 was also associated with abnormalities in the de...

  17. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  18. Comparison of mineral trioxide aggregate and formocresol as pulp-capping agents in pulpotomized primary teeth.

    Science.gov (United States)

    Agamy, Hadeer A; Bakry, Niveen S; Mounir, Maha M F; Avery, David R

    2004-01-01

    The aim of this study was to use clinical, radiographic, and histologic examinations to compare the relative success of gray mineral trioxide aggregate (MTA), white MTA, and formocresol as pulp dressings in pulpotomized primary teeth. Twenty-four children, each with at least 3 primary molars requiring pulpotomy, were selected for this study's clinical and radiographic portion. An additional 15 carious primary teeth planned for serial extraction were selected for this study's histologic portion. All selected teeth were evenly divided into 3 test groups and treated with pulpotomies. Gray MTA was used as the pulp dressing for one third of the teeth, white MTA was the dressing for one third, and the remaining one third were treated with formocresol. The treated teeth selected for the clinical and radiographic evaluations were monitored periodically for 12 months. The treated teeth selected for histologic study were monitored periodically and extracted 6 months postoperatively. Four children with 12 pulpotomized teeth failed to return for any follow-up evaluations in the clinical and radiographic study. Of the remaining 60 teeth in 20 patients, 1 tooth (gray MTA) exfoliated normally and 6 teeth (4 white MTA and 2 formocresol) failed due to abscesses. The remaining 53 teeth appeared to be clinically and radiographically successful 12 months postoperatively. Pulp canal obliteration was a radiographic finding in 11 teeth treated with gray MTA and 1 tooth treated with white MTA. In the histologic study, both types of MTA successfully induced thick dentin bridge formation at the amputation sites, while formocresol induced thin, poorly calcified dentin. Teeth treated with gray MTA demonstrated pulp architecture nearest to normal pulp by preserving the odontoblastic layer and delicate fibrocellular matrix, yet few inflammatory cells or isolated calcified bodies were seen. Teeth treated with white MTA showed a denser fibrotic pattern, with more isolated calcifications in the

  19. Wound healing process of injured pulp tissues with emdogain gel.

    Science.gov (United States)

    Kaida, Hikaru; Hamachi, Takafumi; Anan, Hisashi; Maeda, Katsumasa

    2008-01-01

    This study aimed to investigate the wound healing process of injured pulp tissues with Emdogain gel (EMD). Pulpotomy was performed for the first molars of the mandibles in rats. EMD or Vitapex (VIT)-containing calcium hydroxide was applied to the exposed pulp tissues. The treated teeth were extracted after 7, 14, and 28 days and prepared for histologic examination. In the VIT-treated group, the number of interleukin-1 beta (IL-1 beta)-expressing macrophages initially increased, followed by that of transforming growth factor-beta1 (TGF-beta1)-expressing macrophages. The number of cells expressing bone morphogenetic proteins (BMPs) gradually increased with reparative dentin formation. Meanwhile, in the EMD-treated group, cells expressing IL-1 beta or TGF-beta1 were few. However, the number of BMP-expressing cells, partly macrophages, increased in the early phase, and large amounts of reparative dentin were observed. This study demonstrated that different healing processes existed for EMD and VIT. BMP-expressing macrophages might play important roles in reparative dentin formation.

  20. Dentin bonding--state of the art 1999.

    Science.gov (United States)

    Perdigão, J; Lopes, M

    1999-12-01

    The adhesion of restorative materials to the hard components of tooth structure has been a goal pursued by many researchers ever since Buonocore established the foundation for adhesive and preventive dentistry. Based on the industrial use of phosphoric acid to obtain better adhesion of paints and resin coatings to metal surfaces, Buonocore proposed that phosphoric acid could be used to transform the surface of enamel to "render it more receptive to adhesion." Subsequent research indicated that the formation of taglike resin prolongations into the enamel microporosities was the leading bonding mechanism of resin to phosphoric acid-etched enamel. The enamel bonding agents of the 1960s and 1970s progressively evolved into complex multibottle or universal adhesives in the early 1990s, which were designed to bond to enamel, dentin, composite, amalgam, porcelain, and non-precious metal. Although bonding to enamel has been a dependable technique, bonding to dentin still represents an overwhelming task because dentin is a naturally wet organic tissue penetrated by a tubular maze containing the odontoblastic process, which communicates with the pulp. This intrinsic moisture may actually benefit the chemistry of the newest adhesive systems, which must be applied on moist dentin to be effective. In fact, the collapse of the collagen that occurs on air-drying may prevent the adhesive monomers from penetrating the network of nano-channels formed by the dissolution of hydroxyapatite crystals between collagen fibrils. In view of the complexity of the mechanisms associated with these mechanisms, the objective of this review article is to summarize the most recent concepts in dentin bonding.

  1. Pulp tissue in sex determination: A fluorescent microscopic study

    Directory of Open Access Journals (Sweden)

    Amit Nayar

    2014-01-01

    Full Text Available Aims: To determine and compare the reliability of pulp tissue in determination of sex and to analyze whether caries have any effect on fluorescent body test. Materials and Methods: This study was carried on 50 maxillary and mandibular teeth (25 male teeth and 25 female teeth, which were indicated for extraction. The teeth are categorized into 5 groups, 10 each (5 from males and 5 from females on the basis of caries progression. The pulp cells are stained with quinacrine hydrochloride and observed with fluorescent microscope for fluorescent body. Gender is determined by identification of Y chromosome fluorescence in dental pulp. Results: Fluorescent bodies were found to be more in sound teeth in males as the caries increase the mean percentage of fluorescent bodies observed decreases in males. We also observed the fluorescent spots in females, and the value of the spot increases in female as the caries progresses, thereby giving false positive results in females. Conclusion: Sex determination by fluorescent staining of the Y chromosome is a reliable technique in teeth with healthy pulps or caries with enamel or up to half way of dentin. Teeth with caries involving pulp cannot be used for sex determination.

  2. Distinctive genetic activity pattern of the human dental pulp between deciduous and permanent teeth.

    Directory of Open Access Journals (Sweden)

    Ji-Hee Kim

    Full Text Available Human deciduous and permanent teeth exhibit different developmental processes, morphologies, histological characteristics and life cycles. In addition, their pulp tissues react differently to external stimuli, such as the pulp sensitivity test, dental trauma and pulp therapy materials. These suggest differences in gene expression and regulation, and in this study we compared gene-expression profiles of the human dental pulp from deciduous and permanent teeth. Pulp tissues from permanent premolars and deciduous molars aged 11-14 years were extirpated and mRNA was isolated for cDNA microarray analysis, and quantitative real-time PCR (qPCR. Other teeth were used for immunohistochemical analysis (IHC. Microarray analysis identified 263 genes with a twofold or greater difference in expression level between the two types of pulp tissue, 43 and 220 of which were more abundant in deciduous and permanent pulp tissues, respectively. qPCR analysis was conducted for eight randomly selected genes, and the findings were consistent with the cDNA microarray results. IHC confirmed that insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1 was broadly expressed in deciduous dental pulp tissue, but minimally expressed in permanent dental pulp tissue. Immunohistochemical analysis showed that calbindin 1 (CALB1, leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5, and gamma-aminobutyric acid A receptor beta 1 (GABRB1 were abundantly expressed in permanent predentin/odontoblasts, but only minimally expressed in deciduous dental pulp tissue. These results show that deciduous and permanent pulp tissues have different characteristics and gene expression, suggesting that they may have different functions and responses to therapies focused on pulp or dentin regeneration.

  3. Potential dental pulp revascularization and odonto-/osteogenic capacity of a novel transplant combined with dental pulp stem cells and platelet-rich fibrin.

    Science.gov (United States)

    Chen, Yong-Jin; Zhao, Yin-Hua; Zhao, Ya-Juan; Liu, Nan-Xia; Lv, Xin; Li, Qiang; Chen, Fa-Ming; Zhang, Min

    2015-08-01

    Our aim is to investigate the cytobiological effects of autologous platelet-rich fibrin (PRF) on dental pulp stem cells (DPSCs) and to explore the ectopic and orthotopic possibilities of dental pulp revascularization and pulp-dentin complex regeneration along the root canal cavities of the tooth by using a novel tissue-engineered transplant composed of cell-sheet fragments of DPSCs and PRF granules. Canine DPSCs were isolated and characterized by assaying their colony-forming ability and by determining their cell surface markers and osteogenic/adipogenic differentiation potential. The biological effects of autologous PRF on DPSCs, including cell proliferation, alkaline phosphatase (ALP) activity and odonto-/osteogenic gene expression, were then investigated and quantified. A novel transplant consisting of cell-sheet fragments of DPSCs and PRF granules was adopted to regenerate pulp-dentin-like tissues in the root canal, both subcutaneously in nude mice and in the roots of canines. PRF promoted the proliferation of DPSCs in a dose- and time-dependent manner and induced the differentiation of DPSCs to odonto-/osteoblastic fates by increasing the expression of the Alp, Dspp, Dmp1 and Bsp genes. Transplantation of the DPSC/PRF construct led both to a favorable regeneration of homogeneous and compact pulp-like tissues with abundantly distributed blood capillaries and to the deposition of regenerated dentin along the intracanal walls at 8 weeks post-operation. Thus, the application of DPSC/PRF tissue constructs might serve as a potential therapy in regenerative endodontics for pulp revitalization or revascularization.

  4. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  5. wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  6. Dentinal tubules driven wetting of dentin: Cassie-Baxter modelling

    Science.gov (United States)

    Ramos, S. M. M.; Alderete, L.; Farge, P.

    2009-10-01

    We investigate the wetting properties of dentin surfaces submitted to a phosphoric acid etching followed by an air drying procedure, as in clinical situations of adhesive dentistry. The surface topography of the etched surfaces was characterized by AFM, and the wetting properties of water on these rough and heterogeneous surfaces were studied, by contact angle measurements. We showed that the contact angle increases with the acid exposure time and consequently with both surface roughness and the organic-mineral ratio of the dentin components. From the whole results, obtained on dentin and also on synthesized hydroxyapatites samples, we inferred a water contact angle of ˜ 133° on the dentinal tubule. These experimental results may be described by the Cassie-Baxter approach, and it is suggested that small air pockets could be formed inside the dentinal tubules.

  7. The dentinal surface: its influence on dentinal adhesion. Part I.

    Science.gov (United States)

    Eick, J D; Cobb, C M; Chappell, R P; Spencer, P; Robinson, S J

    1991-12-01

    Three categories of dentinal adhesive are proposed: category I includes adhesives with shear bond strength values between 5 and 7 MPa; category II includes dentinal adhesives with shear bond strengths between 8 and 14 MPa; and category III includes adhesives with shear bond strength values up to 20 MPa. In part I of this article, photomicrographs of the dentinal smear layer and three category I first-generation dentin-adhesive interfaces are presented. The photomicrographs show that the wetting and penetration of the first-generation dentinal adhesives were not adequate to produce high shear bond strengths. When the category I adhesives were tested for shear bond strength, failures occurred at the interface or in the resin adhesive. Future articles will explain wetting and adhesive performance of category II and III adhesives.

  8. SCANNING ELECTRON MICROSCOPIC INVESTIGATION OF DENTINAL TUBULES IN MONKEY DENTIN SCANNING ELECTRON MICROSCOPIC INVESTIGATION OF DENTINAL TUBULES IN Cebus apella DENTIN

    Directory of Open Access Journals (Sweden)

    João Humberto Antoniazzi

    2009-12-01

    Full Text Available

    The aim of the study was to investigate the number and diameter of the Cebus apella dentinal tubules. The roots of the Cebus apella teeth were examined in specific tooth locations: the apical, middle and cervical dentin. The calculations were based on the scanning electron microscope photographs of the fractured surfaces. The results showed that the average number of dentinal tubules for each location was: 74,800 tubules/mm2 for apical root dentin, 90,000 tubules/mm2 for mid-root dentin, 91,600 tubules/mm2 for cervical root dentin. The average diameter was the following: apical root dentin, 4,30µm; mid-root dentin, 4,37µm; cervical root dentin,  5,23µm. These findings demonstrate that the Cebus apella teeth are a suitable substitute for human in endodontics studies. 

    KEY WORDS: Dentin, dentinal tubules, teeth.
    The aim of the study was to investigate the number and diameter of the Cebus apella dentinal tubules. The roots of the Cebus apella teeth were examined in specific tooth locations: the apical, middle and cervical dentin. The calculations were based on the scanning electron microscope photographs of the fractured surfaces. The results showed that the average number of dentinal tubules for each location was: 74,800 tubules/mm2 for apical root dentin, 90,000 tubules/mm2 for mid-root dentin, 91,600 tubules/mm2 for cervical root dentin. The average diameter was the following: apical root dentin, 4,30µm; mid-root dentin, 4,37µm; cervical root dentin,  5,23µm. These findings demonstrate that the Cebus apella teeth are a suitable substitute for human in endodontics studies. 

    KEY WORDS: Dentin, dentinal tubules, teeth.

  9. Wire Chamber

    CERN Multimedia

    1986-01-01

    Two wire chambers made originally for the R807 Experiment at CERN's Intersecting Storage Rings. In 1986 they were used for the PS 201 experiment (Obelix Experiment) at LEAR, the Low Energy Antiproton Ring. The group of researchers from Turin, using the chambers at that time, changed the acquisition system using for the first time 8 bit (10 bit non linear) analog to digital conversion for incoming signals from the chambers. The acquisition system was controlled by 54 CPU and 80 digital signal processors. The power required for all the electronics was 40 kW. For the period, this system was one of the most powerful on-line apparatus in the world. The Obelix Experiment was closed in 1996. To find more about how a wire chamber works, see the description for object CERN-OBJ-DE-038.

  10. A Histological Comparison of a New Pulp Capping Material and Mineral Trioxide Aggregate in Rat Molars

    Science.gov (United States)

    Moazzami, Fariborz; Ghahramani, Yasmin; Tamaddon, Ali Mohammad; Dehghani Nazhavani, Ali; Adl, Alireza

    2014-01-01

    Introduction: Recent investigations have attempted to improve regenerative endodontics with the help of stem cell therapy. In vitro studies have shown the ability of different agents to stimulate the differentiation of dental pulp stem cells (DPSC) into odontoblast-like cells. A combination of dexamethasone, β-glycerophosphate and Vitamin D has been proven to induce a successful differentiation. The aim of this animal study was to evaluate the effect of this combination, named odontoblastic differentiating material (ODM), on pulp tissue when used as a capping material. Materials and Methods: Sixty maxillary right and left molars of 30 Sprague-dawley rats were selected for this study. The teeth were exposed under sterile condition. Half of the teeth were capped with mineral trioxide aggregate (MTA) and the other half with ODM. All cavities were restored with glass ionomer. The rats were sacrificed at post-operative intervals of 2 weeks and 2 months. Samples were histologically evaluated for the degree of inflammation and reparative dentin formation. Finally the data was analyzed with Mann-Whitney and Chi-Square tests. Results: Reparative dentin formed in all groups within both time periods and there was no statistically significant difference between the groups in the mentioned time periods. The MTA group, however, showed a statistically significant reduction in inflammation at both time intervals (P<0.05). Compared to MTA, ODM samples showed a greater amount of inflammation in the pulp tissue. Conclusion: ODM, as a pulp capping material, can induce dentinal bridge formation. PMID:24396376

  11. OPTIMIZING EUCALYPTUS PULP REFINING

    Institute of Scientific and Technical Information of China (English)

    Vail Manfredi

    2004-01-01

    This paper discusses the refining of bleached eucalyptus kraft pulp (BEKP).Pilot plant tests were carried out in to optimize the refining process and to identify the effects of refining variables on final paper quality and process costs.The following parameters are discussed: pulp consistency, disk pattern design, refiner speed,energy input, refiner configuration (parallel or serial)and refining intensity.The effects of refining on pulp fibers were evaluated against the pulp quality properties, such as physical strengths, bulk, opacity and porosity, as well as the interactions with papermaking process, such as paper machine runnability, paper breaks and refining control.The results showed that process optimization,considering pulp quality and refining costs, were obtained when eucalyptus pulp is refined under the lowest intensity and the highest pulp consistency possible. Changes on the operational refining conditions will have the highest impact on total energy requirements (costs) without any significant effect on final paper properties.It was also observed that classical ways to control the industrial operation, such as those based on drainage measurements, do not represent the best alternative to maximize the final paper properties neither the paper machine runability.

  12. Pulp regeneration after non-infected and infected necrosis, what type of tissue do we want?

    DEFF Research Database (Denmark)

    Andreasen, Jens O; Bakland, Leif K

    2012-01-01

    that such events may take place in four variants: (i) Revascularization of the pulp with accelerated dentin formation leading to pulp canal obliteration. This event has a good long-term prognosis. (ii) Ingrowth of cementum and periodontal ligament (PDL). The long-term prognosis for this event is not known. (iii......) Ingrowth of cementum, PDL, and bone. The long-term prognosis is only partly known, but cases developing an internal ankylosis have been described. (iv) Ingrowth of bone and bone marrow is a rare phenomenon and the long-term prognosis does not appear to be good. Based on current knowledge, expectations...... with respect to pulp regeneration (revitalization) of infected necrotic dental pulps are difficult to predict; more information than now available is needed before procedures for pulpal regeneration can be routinely recommended with a predictable long-term prognosis....

  13. Preliminary report on the effects of propolis on wound healing in the dental pulp.

    Science.gov (United States)

    Bretz, W A; Chiego, D J; Marcucci, M C; Cunha, I; Custódio, A; Schneider, L G

    1998-01-01

    The purpose of this investigation was to determine the antimicrobial and healing potential of propolis on direct dental pulp exposures. This study used 25 adult male rats. Pulp exposures were performed and animals were allocated to propolis and calcium hydroxide (Ca(OH)2 groups. Animals were killed on days 5, 7, 10, and 14. The teeth were routinely processed for histological evaluation. Non-parametric tests were employed to analyze the data. No significant differences were found between study groups on the wound healing of the dental pulp. Both substances were comparable in exhibiting normal reorganization of the pulp and no increased vascularity, and were equally efficacious in maintaining a low inflammatory and microbial cell population as well as in stimulating the formation of reparative dentin.

  14. Dentin permeability: determinants of hydraulic conductance.

    Science.gov (United States)

    Reeder, O W; Walton, R E; Livingston, M J; Pashley, D H

    1978-02-01

    A technique is described which permits measurements of the ease with which fluid permeates dentin. This value, the hydraulic conductance of dentin, increased as surface area increases and/or as dentin thickness decreases. It increased 32-fold when dentin was acid etched due to removal of surface debris occluding the tubules.

  15. Deposition of growth layer groups in dentine tissue of captive common dolphins Delphinus delphis

    Directory of Open Access Journals (Sweden)

    Sinéad Murphy

    2014-07-01

    Full Text Available Knowledge of age structure and longevity (maximum age are essential for modelling marine mammal population dynamics. Estimation of age in common dolphins (Delphinus spp. is primarily based on counting Growth Layer Groups (GLGs in the dentine of thin, decalcified and stained sections of teeth. An annual incremental deposition rate was validated for Delphinus spp. 30-years ago through the use of tetracycline. However, it is not known if the pulp cavity becomes occluded in older individuals or GLGs continue to be deposited in dentine tissue. To investigate the deposition of GLGs in dentine tissue, teeth samples were obtained during the necropsies of two short-beaked common dolphins (Delphinus delphis that were held in captivity for 31 and 33 years in New Zealand. Individuals were captured together in Hawkes Bay, North Island, New Zealand and classified as juveniles based on physical appearance. Teeth were processed in two ageing laboratories, using four different bone decalcifiers, two sectioning techniques incorporating the use of both a freezing microtome (-20°C and paraffin microtome, and two different stains. An age was estimated for one of the dolphins, in line with that proposed based on estimated age at capture and period in captivity. However, a hypomineralised area was observed in the dentine tissue close to the pulp cavity of the second individual, preventing estimation of maximum age. The presence and structure of this anomaly is explored further within the study.

  16. Semaphorin 3A controls timing and patterning of the dental pulp innervation.

    Science.gov (United States)

    Moe, Kyaw; Sijaona, Angelina; Shrestha, Anjana; Kettunen, Paivi; Taniguchi, Masahiko; Luukko, Keijo

    2012-12-01

    Timing and patterning of dental pulp innervation are strictly spatio-temporally regulated but it is still not known how they are controlled at molecular level. We analyzed postnatal innervation of the dental pulp in the mandibular first molar of mice deficient for Semaphorin 3A (Sema3A) axon repellant molecule. Immunohistochemical localization of nerve fibers on serial sections covering the whole tooth germs using anti-peripherin antibody revealed that nerve fibers were prematurely present within the preodontoblast layer next to the inner enamel epithelium already at PN0 in Sema3A(-/-) mice. In contrast, in the wild-type (Sema3A(+/+)) mice nerve fibers were seen in the pulp only after enamel formation at PN3. The nerves in Sema3A(-/-) pulp were notably defasciculated and thinner compared to that of Sema3A(+/+) mice. A premature formation of an abnormal, enlarged nerve plexus with a high number of arborizations was apparent in the pulp-dentin border target area in Sema3A(-/-) already at PN2 whereas in the wild-type mice the first sign of plexus formation was seen at PN7. The expression of mRNAs for Ngf, Gdnf and Ncam neuroregulatory molecules in mandibular molar as well as receptors for neurotrophic factors and class 3 semaphorins including Sema3A (TrkA, p75, TrkB, TrkC, Ret, Npn1, Npn2, PlxA4) in trigeminal ganglia were not altered in the Sema3A(-/-) mice. Collectively, this data show that Sema3A serves an essential role in molar tooth pulp innervation controlling the timing of nerve fiber penetration into the pulp, their patterning and the formation of nerve plexus at pulp-dentin border area, and provide further support for the hypothesis that tooth innervation is regulated by the coordinated activity of locally expressed neuroregulatory molecules exerting positive and negative influences on growing dental nerve fibers.

  17. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  18. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  19. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  20. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  1. Dental trauma. Combination injuries 2. The risk of pulp necrosis in permanent teeth with subluxation injuries and concomitant crown fractures

    DEFF Research Database (Denmark)

    Lauridsen, Eva Fejerskov; Hermann, Nuno Vibe; Gerds, Thomas Alexander

    2012-01-01

    age, crown fracture type, mobility and response to an electric pulp test (EPT) at the initial examination. Results:  Teeth with immature root development: The risk of PN was increased in teeth with a concomitant enamel fracture (log-rank test: P = 0.002), enamel–dentin fracture (log-rank test: P ...The reported risk of pulp necrosis (PN) is generally low in teeth with subluxation injuries. A concomitant crown fracture may increase the risk of PN in such teeth. Aim:  To analyse the influence of a concomitant trauma-related infraction, enamel-, enamel–dentin- or enamel–dentin–pulp fracture...... on the risk of PN in permanent teeth with subluxation injury. Material and Methods:  The study included 404 permanent incisors with subluxation injury from 289 patients (188 male, 101 female). Of these teeth, 137 had also suffered a concomitant crown fracture. All the teeth were examined and treated according...

  2. Root maturation and dentin–pulp response to enamel matrix derivative in pulpotomized permanent teeth

    Directory of Open Access Journals (Sweden)

    Sherif S Darwish

    2014-01-01

    Full Text Available The success of pulpotomy of young permanent teeth depends on the proper selection of dressing materials. This study aimed to evaluate the histological and histomorphometric response of dentin–pulp complex to the enamel matrix derivative (Emdogain® gel compared to that of calcium hydroxide when used as a pulp dressing in immature young permanent dogs’ teeth. Dentin-like tissues bridging the full width of the coronal pulp at the interface between the injured and healthy pulp tissues were seen after 1 month in both groups. With time, the dentin bridge increased in thickness for calcium hydroxide but disintegrated and fully disappeared for Emdogain-treated group. Progressive inflammation and total pulp degeneration were only evident with Emdogain-treated group. The root apices of Emdogain-treated teeth became matured and closed by cementum that attached to new alveolar bone by a well-oriented periodontal ligament. In young permanent dentition, Emdogain could be a good candidate for periodontium but not dentino–pulpal complex regeneration.

  3. Appropriate electrode placement site of electric pulp tester for the premolars: A clinical study

    Directory of Open Access Journals (Sweden)

    Seema Dinesh Bargale

    2015-01-01

    Full Text Available Context: Electric pulp testers (EPTs are widely used as diagnostic aid in dentistry for dental pulp. This delivers enough current to overcome enamel and dentin resistance and to stimulate the myelinated sensory fibers at the junction of pulp and dentin. Such testing requires the electrode to be in contact with the surface of the tooth, with optimal positions identified for anterior teeth, premolars, and molars. Aims: To determine the best site position of EPT on premolars. The objective of electric pulp testing was to determine the sensibility of each premolar at the lowest sensory response threshold. Settings and Design: Clinical study Materials and Methods: The premolars of 20 patients between 13 and 15 years accompanied with parents, free of restorations, and caries were selected. Five sites on the crown were tested with EPT for minimum of four times. Statistical analysis used: One-way analysis of variance test and the Tukey′s honestly significant difference test. Results: The lowest threshold response was noted at the incisal edge of the tooth; the middle third had a higher threshold among all the different placement of electrode. Statistically significant difference was observed for occlusal surface in terms of region of placement of electrode. Conclusions: This experiment found the best electrode site for pulp testing in premolars. The appropriate EPT site was on the occlusal surface of maxillary and mandibular premolars.

  4. Pulp response to a novel adhesive calcium hydroxide based cement.

    Science.gov (United States)

    Watts, A; Paterson, R C; Cohen, B D; Combe, E C

    1994-09-01

    This study compares pulp responses to 3 formulations of calcium hydroxide, namely: a) An experimental adhesive calcium hydroxide cement containing polyacrylic acid, b) Dycal (L.D> Caulk Co, Milford, Delaware) Batch Nos 176970/176990, c) "Analar" calcium hydroxide mixed with sterile distilled water. After 28 days dentine bridges were present in 77% of teeth capped with the test material, 64% of teeth treated with Dycal and in 62% of teeth capped with calcium hydroxide and water. Inflammatory infiltrates were observed in a number of teeth remote from the bridges. Bacteria were detected in these specimens. Exposed rat molar pulp responses to an experimental adhesive calcium hydroxide cement were similar to to those observed with 2 other calcium hydroxide formulations.

  5. Pulp tissue from primary teeth: new source of stem cells

    Directory of Open Access Journals (Sweden)

    Paloma Dias Telles

    2011-06-01

    Full Text Available SHED (stem cells from human exfoliated deciduous teeth represent a population of postnatal stem cells capable of extensive proliferation and multipotential differentiation. Primary teeth may be an ideal source of postnatal stem cells to regenerate tooth structures and bone, and possibly to treat neural tissue injury or degenerative diseases. SHED are highly proliferative cells derived from an accessible tissue source, and therefore hold potential for providing enough cells for clinical applications. In this review, we describe the current knowledge about dental pulp stem cells and discuss tissue engineering approaches that use SHED to replace irreversibly inflamed or necrotic pulps with a healthy and functionally competent tissue that is capable of forming new dentin.

  6. OPTIMIZING EUCALYPTUS PULP REFINING

    Institute of Scientific and Technical Information of China (English)

    VailManfredi

    2004-01-01

    This paper discusses the refining of bleachedeucalyptus kraft pulp (BEKP).Pilot plant tests were carded out in to optimize therefining process and to identify the effects of refiningvariables on final paper quality and process costs.The following parameters are discussed: pulpconsistency, disk pattern design, refiner speed,energy input, refiner configuration (parallel or serial)and refining intensity.The effects of refining on pulp fibers were evaluatedagainst the pulp quality properties, such as physicalstrengths, bulk, opacity and porosity, as well as theinteractions with papermaking process, such as papermachine runnability, paper breaks and refiningcontrol.The results showed that process optimization,considering pulp quality and refining costs, wereobtained when eucalyptus pulp is refined under thelowest intensity and the highest pulp consistencypossible. Changes on the operational refiningconditions will have the highest impact on totalenergy requirements (costs) without any significanteffect on final paper properties.It was also observed that classical ways to control theindustrial operation, such as those based on drainagemeasurements, do not represent the best alternative tomaximize the final paper properties neither the papermachine runability.

  7. The effects of current dentinal adhesives on the dentinal surface.

    Science.gov (United States)

    Chappell, R P; Spencer, P; Eick, J D

    1994-12-01

    The effects of the dentinal surface treatments from six currently available commercial dentinal adhesives are presented. The adhesives are All-Bond 2, etched and unetched, Syntac, Prisma Universal Bond 3, Scotchbond Multipurpose, Tenure Solution, and Adhesive By Choice. Unerupted third molar human teeth were sectioned and treated with the appropriate adhesive according to the manufacturer's directions. After the teeth were treated, they were processed for observation by scanning electron microscopy. Scanning-electron microscopic photomicrographs were made of each step in the process to show the effects of the constituents, including the adhesives, on the dentinal surface. For All-Bond 2, unetched, the smear layer was not removed before the primer and the adhesive were applied. The primer for Prisma Universal Bond 3 altered the smear layer by reacting with it but did not produce a large demineralized zone in the dentin. All the other adhesives did remove the smear layer before the tooth was treated with the primer and adhesive.

  8. Environmental scanning electron microscopy of hydrated conditioned/etched dentine.

    Science.gov (United States)

    de Wet, F A; van der Vyver, P J; Eick, J D; Dusevich, V M

    2000-11-01

    Various etchants/conditioners are used during dental treatment to affect or remove the smear layer. The purpose of this study was to evaluate the effect of different treatments on moist dentine, using a field emission environmental scanning electron microscope (FE-ESEM). Twenty freshly extracted, human molar teeth were utilised. The roots and pulps were removed, and the crowns horizontally sectioned with a low speed diamond saw (Isomet) (with cooling in a saline solution) in order to expose superficial dentine. A smear layer was created on these surfaces by using 600 grit silicone carbide paper. Test surfaces were then treated in one of the following ways: 1. 37% phosphoric acid liquid 2. 37% phosphoric acid gel 3. NRC (non-rinse conditioner) without rinsing 4. NRC with rinsing. Shallow grooves were cut on the untreated sides, using a thin diamond bur. This enabled the samples to be split in half when pressure was applied in the grooves. Samples were maintained moist throughout specimen preparation. Samples were examined in the FE-ESEM (Philips XL 30) in such a way that the effect of the treatment could be viewed occlusally, as well as perpendicular to the treated interface. Phosphoric acid liquid and gel removed the smear layer, and demineralised the dentine for approximately 5-10 micrometers. NRC penetrated the smear layer and modified it to a lesser degree. However, washing of the NRC treated surface removed part of the smear layer, and opened up some dentinal tubules. Excellent resolution was possible with the FE-ESEM in both the wet and dry modes.

  9. The influence of liners on the pulp inflammation

    Directory of Open Access Journals (Sweden)

    Davidović Lado

    2015-01-01

    Full Text Available Introduction. The study included application of liners and dental composites in to cavities of six experimental animals - rabbits (Oryctolagus cuniculus. Objective. The aim of the study was to investigate rabbit dental pulp response to different liners. Methods. Cavity preparation for class V were made on the maxillary central incisors and one lower incisor, while the second lower incisor served as a control tooth. These teeth were restored with the use of one of the following liners - Calcimol LC, ANA Liner and Fuji II LC Improved, and Ceram-X mono dental composite. After an observation period of five days animals were sacrificed and prepared for histological analysis. The existence and degree of the pulp inflammation was determined by using a light microscope. Results. Results showed that the used liners do not cause distortion of the structure and continuity of the odontoblastic layer. Inflammation was not registered in the control group, while in each group of tested materials one tooth with mild signs of hyperemia was registered. Results showed that all three tested liners demonstrated favorable effects on the pulp of the tooth and did not lead to inflammatory reactions. Conclusion. Histological analysis of the dental pulp of experimental animals suggests that the liners used in this study do not compromise the integrity of the odontoblastic layer, if it is applied over a thin layer of dentin. In each group of tested materials one tooth with mild signs of hyperemia and vasodilation was registered.

  10. DIRECT PULP CAPPING IN TREATMENT OF REVERSIBLE PULPITIS IN PRIMARY TEETH- CLINICAL PROTOCOL

    Directory of Open Access Journals (Sweden)

    Nina Milcheva

    2016-10-01

    Full Text Available The pulp of primary teeth is identical morphologically and physiologically to that of permanent teeth and it is capable to answer to pathological stimuli by producing tertiary dentin. When the inflammation of the pulp is in its reversible stage vital methods of treatment are indicated in order to stimulate the healing processes in it and protect its vitality. In Bulgaria the most popular method of treatment of inflammation diseases of the pulp in primary dentition is the mortal amputation. The biological way of treatment is not very common even in cases where there are indications for it. Purpose: The aim of this paper is to present the approbated by us protocol for application of direct pulp capping for treatment of reversible pulpitis in primary teeth. Material and methods: On the base of world experience and our contemporary meta- analysis of the researches published in the last 15 years concerning the problems of diagnostics. We determined clinical and radiographic diagnostic criteria for reversible pulpitis in primary teeth and indications for application of direct pulp capping as a method of treatment. We give clinical steps for application of the method and summarized the clinical and radiographic criteria for success after treatment. Results/conclusion: We gather all the information for applying direct pulp cappingfor treatment of reversible pulpitis in primary dentition. We offer the method of direct pulp capping as a clinical protocol “step by step” and illustrated by scheme which can be useful for students and dentists in their everyday practice.

  11. Human pulp response after partial pulpotomy with two calcium hydroxide products.

    Science.gov (United States)

    Sübay, R K; Suzuki, S; Suzuki, S; Kaya, H; Cox, C F

    1995-09-01

    Twenty human permanent teeth were used to study the pulpal response of two calcium hydroxide products, Dycal and Pulpdent Multi-Cal, after partial pulpotomy. Teeth were extracted at 4 months, fixed, and prepared for histologic examination. All 10 teeth treated with Dycal showed complete soft tissue healing and bridge formation. No stained bacteria were seen throughout the serial sections. One tooth treated with Dycal showed acceptable histologic results, dentin deposition in the root canal. Six cases dressed with Pulpdent Multi-Cal showed acceptable histologic results, whereas four teeth showed severe inflammation or necrosis associated with bacterial penetration into the pulp tissue. Clinically, one tooth treated with Pulpdent Multi-Cal showed pulpal pain and was extracted at 90 days. Our data support the thesis that human permanent pulps will promote tissue healing and dentin bridge formation as long as bacterial microleakage is excluded.

  12. Carious dentine removal: current approach

    Directory of Open Access Journals (Sweden)

    Germana Coeli de Farias Sales

    2008-01-01

    Full Text Available Dentistry is renewed day after day through the results of qualified researches. The approach as regards carious dentin removal is goingthrough questioning and innovation. The scope of this study was to perform a literature review in the sense of elucidating questions pertaining to the problem of whether or not it is necessary to completely remove carious dentin, and the possibility of performing restoration in a single session, in addition to a discussion about which type of material should be applied in this type of substrate. After analyzing the referenced articles, it was concluded that the stepwise treatment controls caries progression; there is a trend in the literature to partially remove the carious dentin in deep lesions and perform definitive restoration; Calcium hydroxide cement is a classical liner in these situations, while glass ionomer cement and resinous materials are other possibilities of materials that can be in close contact with the remaining dentin.

  13. How can sensitive dentine become hypersensitive and can it be reversed?

    Science.gov (United States)

    Pashley, David H

    2013-07-01

    This paper reviews a number of studies in oral biology and endodontics that deal with the reactivity of the pulpo-dentine complex in response to mechanical and immunological stimuli. It can be hypothesized that these reactions could also apply to changes in dentine sensitivity following periodontal procedures. Some of these changes involve neurogenic inflammation of the pulp under exposed open tubules; this increases the rate of outward fluid flow through the tubules, making the overlying exposed dentine more sensitive. Other changes may be due to inflammation-related nerve sprouting of pulpal nerves, which can lead to innervation of more tubules than normal. Changes may also involve upregulation of new, more sensitive ion channels in the membranes of these nerves. The goal of the paper is to increase awareness of the complex issues involved in dentine sensitivity, so that future investigators may develop agents or techniques to stimulate mechanisms that mitigate dentine sensitivity, or to block mechanisms that aggravate the condition, for therapeutic effect.

  14. The role of toothpaste in the aetiology and treatment of dentine hypersensitivity.

    Science.gov (United States)

    Addy, M; West, N X

    2013-01-01

    Dentine hypersensitivity (DH) is a common, painful dental condition with a multi-factorial aetiology. The hydrodynamic mechanism theory to explain dentine sensitivity also appears to fit DH: lesions exhibiting large numbers of open dentinal tubules at the surface and patent to the pulp. By definition, DH can only occur when dentine becomes exposed (lesion localisation) and tubules opened (lesion initiation), thus permitting increased fluid flow in tubules on stimulation. Erosion, particularly from dietary acids appears to play a dominant role in both processes. Toothbrushing with most toothpaste products alone cause clinically insignificant wear of enamel but are additive, even synergistic, to erosive enamel loss. Additionally, toothbrushing with toothpaste is implicated in 'healthy' gingival recession. Toothbrushing with most toothpastes removes the smear layer to expose tubules and again can exacerbate erosive loss of dentine. These findings thereby implicate toothbrushing with toothpaste in the aetiology of DH. Management of the condition should have secondary prevention at the core of treatment and therefore, must consider first and foremost the aetiology. Fluoride toothpaste at present appears to provide little primary or secondary preventive benefits to DH; additional ingredients can provide therapeutic benefits. Potassium-based products to block pulpal nerve response have caused much debate and are considered by many as unproven, which should not translate to ineffective. Several toothpaste technologies formulated to block tubules are from studies in vitro, in situ and controlled clinical trials considered proven for the treatment of DH.

  15. Low-level laser therapy of dentin hypersensitivity: a short-term clinical trial.

    Science.gov (United States)

    Orhan, Kaan; Aksoy, Umut; Can-Karabulut, Deniz C; Kalender, Atakan

    2011-09-01

    The aim of this study was to evaluate low-level laser therapy in cervical dentin hypersensitivity. A randomized controlled clinical trial was conducted with a total of 64 teeth. Dentin desensitizer and diode laser were applied on the cervical dentin surfaces. Distilled water and placebo laser was used as the placebo groups. The irradiance used was 4 J/cm(2) per treatment site. The baseline measurement of hypersensitivity was made by using visual analog scale (VAS). Twenty-four hours and 7 days after the application of desensitizer, diode laser and placebo groups, a new VAS analysis was conducted for the patients' sensitivity level. The mean pain scores of placebo groups were significantly higher than the desensitizer's and diode laser's mean scores (ANOVA, p low-level laser therapy and no statistically significant difference was observed between these two treatments (p > 0.05). Although low-level laser and glutaraldehyde containing desensitizer present distinct modes of action, experimental agents caused a significant reduction of dentin hypersensitivity without showing secondary effects, not irritating the pulp or causing pain, not discoloring or staining the teeth, and not irritating the soft tissues at least for a period of 1 week with no drawbacks regarding handling and/or ease of application. Low-level laser therapy and desensitizer application had displayed similar effectiveness in reducing moderate dentin hypersensitivity.

  16. Clinical effect of photodynamic therapy on primary carious dentin after partial caries removal

    Directory of Open Access Journals (Sweden)

    Pierre Adriano Moreno NEVES

    2016-01-01

    Full Text Available Abstract This study was conducted to assess the clinical effect of photodynamic therapy (PDT in the decontamination of the deep dentin of deciduous molars submitted to partial removal of carious tissue. After cavity preparation, dentin samples were taken from the pulp wall of nineteen deciduous molars before and after PDT application. Remaining dentin was treated with 0.01% methylene blue dye followed by irradiation with an InGaAlP diode laser (λ – 660 nm; 40 mW; 120 J/cm2; 120 s. Dentin samples were microbiologically assessed for the enumeration of total microorganisms, Lactobacillus spp. and mutans streptococci. There was no significant difference in the number of colony-forming units (CFU for any of the microorganisms assessed (p > 0.05. Photodynamic therapy, using 0.01% methylene blue dye at a dosimetry of 120 J/cm2 would not be a viable clinical alternative to reduce bacterial contamination in deep dentin.

  17. Cytotoxicity of DP-bioglass paste used for treatment of dentin hypersensitivity.

    Science.gov (United States)

    Kuo, Tien-Chun; Lee, Bor-Shiunn; Kang, Shu-Han; Lin, Feng-Huei; Lin, Chun-Pin

    2007-04-01

    DP-bioglass mixed with 30% phosphoric acid has been suggested to treat dentin hypersensitivity because the material is able to produce homogeneous occlusion of exposed dentinal tubules and is able to provide a sealing depth of up to 60 microm. The purpose of this study was to investigate the relative cytotoxic effect of the DP-bioglass paste, intermediate restorative material (IRM; DeTrey, Dentsply, Germany), and commercial desensitizing agent (Abmindent; Abmin Technologies Ltd, Turku, Finland) on human dental pulp cells by using a transwell insert model and a dentin-disc model. Cell viability was measured by means of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results of this study indicated that cell viability for the DP-bioglass paste did not differ significantly from those of the IRM or Abmindent in the transwell insert model. In addition, MTT results of DP-bioglass paste were similar to the control group in the dentin-disc model. The results indicated that DP-bioglass paste was a highly biocompatible material and could potentially serve as an effective material for treatment of dentin hypersensitivity.

  18. 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

  19. Biogas generation apple pulp.

    Science.gov (United States)

    Llaneza Coalla, H; Blanco Fernández, J M; Morís Morán, M A; López Bobo, M R

    2009-09-01

    In view of the pressing problem that appears in our region (Asturias, north of Spain) with the residues from the cider production, it was decided to test this kind of material as a co-substrate joint with slaughterhouse waste in a laboratory unit. The anaerobic digestion of apple pulp was investigated for biogas production. This paper presents the results where apple pulp was co-digested with slaughterhouse waste (pig intestine and bovine stomach content) in a biogas laboratory unit (10 l CSTR reactor). The production of biogas has reached very satisfactory values during the whole test (0.8m(3)kg(-1)OTS), verifying that the process is kept in stable conditions of pH (near 8.0), and the volatile fatty acids was always underneath 3000 mg/l, when the pulp amount was lower than 100g in mesophilic conditions. The fat concentration into the digester remained always below the value that causes inhibition of the methanogenic bacteria, 500 mg/l. Finally, methane concentration (77-80%) and H(2)S concentration (400 ppm) in the biogas, they were similar to those obtained when the test was run out in the absence of apple pulp. The process efficiency with respect to COD removal was high, near 80% of the total COD. Finally, inhibitory effects of methanogenic bacteria were observed when pulp concentration was around 10% in the input material.

  20. MMP2-cleavage of DMP1 generates a bioactive peptide promoting differentiation of dental pulp stem/progenitor cell

    Directory of Open Access Journals (Sweden)

    C Chaussain

    2009-11-01

    Full Text Available Dentin Matrix Protein 1 (DMP1 plays a regulatory role in dentin mineralization and can also function as a signaling molecule. MMP-2 (matrix metalloproteinase-2 is a predominant protease in the dentin matrix that plays a prominent role in tooth formation and a potential role during the carious process. The possibility that MMP-2 can cleave DMP1 to release biologically active peptides was investigated in this study. DMP1, both in the recombinant form and in its native state within the dentin matrix, was shown to be a substrate for MMP-2. Proteolytic processing of DMP1 by MMP-2 produced two major peptides, one that contains the C-terminal region of the protein known to carry both the ASARM (aspartic acid and serine rich domain domain involved in biomineralization and the DNA binding site of DMP1. In vitro experiments with recombinant N- and C-terminal polypeptides mimicking the MMP-2 cleavage products of DMP1 demonstrated an effect of the C-polypeptide on the differentiation of dental pulp stem/progenitor cells to a putative odontoblast phenotype. In vivo implantation of this peptide in a rat injured pulp model induced a rapid formation of a homogeneous dentin bridge covered by a palisade of orientated cells expressing dentin sialoprotein (DSP and DMP1, attesting an efficient repair process. These data suggest that a peptide generated through the proteolytic processing of DMP1 by MMP-2 can regulate the differentiation of mesenchymal cells during dentinogenesis and thus sustain reparative dentin formation in pathological situations such as carious decay. In addition, these data open a new therapeutic possibility of using this peptide to regenerate dentin after an injury.

  1. Human tooth culture: a study model for reparative dentinogenesis and direct pulp capping materials biocompatibility.

    Science.gov (United States)

    Téclès, Odile; Laurent, Patrick; Aubut, Virginie; About, Imad

    2008-04-01

    In a previous work, based on an in vitro entire tooth culture model of human immature third molars, we demonstrated that perivascular progenitor cells can proliferate and migrate to the injury site after pulp exposure. In this work, we investigated the differentiation of cells after direct capping with biomaterials classically used in restorative dentistry. Histological staining after direct pulp capping with Calcium Hydroxide XR(R) or MTA revealed early and progressive mineralized foci formation containing BrdU-labeled sequestered cells. The molecular characterization of the matrix and the sequestered cells by immunohistochemistry (Collagene type I, Dentin sialoprotein, and Nestin) clearly demonstrates that these areas share common characteristics of the mineralized matrix of reparative dentin formed by odontoblast-like cells. This reproduces some features of the pulp responses after applying these materials in vivo and demonstrates that the entire tooth culture model reproduces a part of the early steps of dentin regeneration in vivo. Its future development may be useful in studying the effects of biomaterials on this process.

  2. Mineralized polycaprolactone nanofibrous matrix for odontogenesis of human dental pulp cells.

    Science.gov (United States)

    Kim, Jong-Jin; Bae, Won-Jung; Kim, Joung-Mok; Kim, Jung-Ju; Lee, Eun-Jung; Kim, Hae-Won; Kim, Eun-Cheol

    2014-03-01

    The aim of the present study was to fabricate mineralized polycaprolactone nanofibrous scaffold and investigate its ability to elicit odontogenic differentiation of human dental pulp cells, compared to the pure polycaprolactone scaffold. Polycaprolactone nanofibrous scaffold was produced by electrospinning, and the surface was mineralized with apatite. Cellular behaviors on the mineralized polycaprolactone scaffold were assessed in terms of cell adhesion, growth, and odontoblastic differentiation. To evaluate the signal transduction of human dental pulp cells, mRNA expression was analyzed and Western blotting was performed. Mineralized polycaprolactone showed improved cell proliferation, mineralized nodule formation, and expression of odontoblastic marker genes including alkaline phosphatase, osteopontin, osteocalcin, dentin sialophosphoprotein (DSPP), and dentin matrix protein-1, as compared with pure polycaprolactone. Although the cell adhesion on the mineralized polycaprolactone was similar to that of the polycaprolactone, the expression level of proteins including collagen type I and the key adhesion receptor (integrin components α1, α2, and β1) was upregulated in mineralized polycaprolactone compared to polycaprolactone. Especially, cells seeded onto mineralized polycaprolactone scaffolds showed significantly increased levels of phosphorylated focal adhesion kinase, a marker of integrin activation, and downstream pathways, such as phosphor (p)-Akt, p-extracellular signal regulated kinase, p-c Jun N-terminal kinase, nuclear factor-kappa B, c-fos, and c-jun, compared with pure polycaprolactone. The mineralized polycaprolactone scaffold is attractive for dentin tissue engineering by promoting growth and odontogenic differentiation of human dental pulp cells through the integrin-mediated signaling pathway.

  3. Enamel Matrix Derivative Promote Primary Human Pulp Cell Differentiation and Mineralization

    Directory of Open Access Journals (Sweden)

    Elisabeth Aurstad Riksen

    2014-05-01

    Full Text Available Enamel matrix derivative (EMD has been found to induce reactive dentin formation; however the molecular mechanisms involved are unclear. The effect of EMD (5–50 μg/mL on primary human pulp cells were compared to untreated cells and cells incubated with 10−8 M dexamethasone (DEX for 1, 2, 3, 7, and 14 days in culture. Expression analysis using Affymetrix microchips demonstrated that 10 μg/mL EMD regulated several hundred genes and stimulated the gene expression of proteins involved in mesenchymal proliferation and differentiation. Both EMD and DEX enhanced the expression of amelogenin (amel, and the dentinogenic markers dentin sialophosphoprotein (DSSP and dentin matrix acidic phosphoprotein 1 (DMP1, as well as the osteogenic markers osteocalcin (OC, BGLAP and collagen type 1 (COL1A1. Whereas, only EMD had effect on alkaline phosphatase (ALP mRNA expression, the stimulatory effect were verified by enhanced secretion of OC and COL1A from EMD treated cells, and increased ALP activity in cell culture medium after EMD treatment. Increased levels of interleukin-6 (IL-6, interleukin-8 (IL-8, and monocyte chemoattractant proteins (MCP-1 in the cell culture medium were also found. Consequently, the suggested effect of EMD is to promote differentiation of pulp cells and increases the potential for pulpal mineralization to favor reactive dentine formation.

  4. EFFECT OF SCREW EXTRUSION PRETREATMENT ON PULPS FROM CHEMICAL PULPING

    Directory of Open Access Journals (Sweden)

    Cuihua Dong,

    2012-07-01

    Full Text Available The effect of compressive pretreatment before chemical pulping on the properties of poplar kraft and soda-AQ pulp was evaluated. Compressive pretreatment not only resulted in the dissolution of hemicellulose, but also leached extractives. Pulps made from compressive pretreated wood chips required lower beating energy than the untreated pulps to achieve the same beating degree of 45°SR, and the brightness of the handsheets was improved by 2% ISO. Compressive pretreatment allowed for efficient delignification and saved about 6% alkali consumption to achieve similar pulp screen yield. Furthermore, a higher content of fines and slightly lower mechanical properties were observed after the compressive treatment.

  5. Dental pulp vitality measurement based on multiwavelength photoplethysmography

    Science.gov (United States)

    Sarkela, Ville; Kopola, Harri K.; Oikarinen, Kyosti; Herrala, Esko

    1995-01-01

    Observation of the intradental blood supply is important in cases of dental trauma, but difficult. As the methods used by dentists to measure pulp vitality are not very reliable, a dental pulp vitalometer based on fiberoptic reflectance measurement and measurement of the absorption of blood has been designed and built. In addition to the fiber optic probe and reflectance sensor electronics, the vitalometer includes a data acquisition card, a PC and data processing programs. The thick dentin and enamel layers and the small amount of blood in a tooth are major problems for optical measurement of its vitality, and scattered light from the enamel and the dentin surrounding the pulpa also causes a problem in measurements based on reflectance. These problems are assessed here by means of theoretical models and calculations. The advantage of reflectance measurement is that only one probe is used, which is easy to put against the tooth. Thus measurements are simple to make. Three wavelengths (560 nm, 650 nm, 850 nm) are used to measure photoplethysmographic signals, and these should allow the oxygen saturation of the blood in a tooth to be measured as well in the future. Series of measurements have been performed on vital and non-vital teeth by recording photoplethysmographic signals, using the vitalometer and using a commercial laser-Doppler instrument. Verifications of the laser-Doppler and vitalometer results are presented and deduced here.

  6. Dental pulp stem cells

    DEFF Research Database (Denmark)

    Ashri, N. Y.; Ajlan, S. A.; Aldahmash, Abdullah M.

    2015-01-01

    Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable...... scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from...... an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors....

  7. Effectiveness of simplified dentin bonding systems.

    Science.gov (United States)

    Imai, T; Itoh, K; Tani, C; Manabe, A; Yamashita, T; Hisamitsu, H; Wakumoto, S

    1998-03-01

    The effectiveness of newly developed commercial dentin bonding systems (SB, MB II and KB) was evaluated by measuring the contraction gap width of a resin composite restored into a cylindrical dentin cavity prepared in an extracted human molar and by measuring the tensile bond strength to the flat dentin surface. In addition, calcium loss during dentin conditioning was analyzed using electron microanalyses. An experimental dentin bonding system composed of EDTA conditioning, GM solution priming and a bonding agent containing 10-MDP was employed as a control in which it was presumed that contraction gap formation was prevented completely. However, gap formation was observed using the three commercial simplified dentin bonding systems. SEM observation showed that the gap was formed between the resin composite and the top surface of the dentin cavity wall indicating that the fracture occurred at the adhesive interface, but never inside the dentin nor inside the resin composite.

  8. Evaluation of dental pulp repair using low level laser therapy (688 nm and 785 nm) morphologic study in capuchin monkeys

    Science.gov (United States)

    Pretel, H.; Oliveira, J. A.; Lizarelli, R. F. Z.; Ramalho, L. T. O.

    2009-02-01

    The aim of this study was to evaluate the hypothesis that low-level laser therapy (LLLT) 688 nm and 785 nm accelerate dentin barrier formation and repair process after traumatic pulp exposure. The sample consisted of 45 premolars of capuchin monkeys (Cebus apella) with pulp exposure Class V cavities. All premolars were treated with calcium hydroxide (Ca(OH)2), divided in groups of 15 teeth each, and analyzed on 7th, 25th, and 60th day. Group GI - only Ca(OH)2, GII - laser 688 nm, and GIII - laser 785 nm. Laser beam was used in single and punctual dose with the parameters: continuous, 688 nm and 785 nm wavelength, tip's area of 0.00785 cm2, power 50 mW, application time 20 s, dose 255 J/cm2, energy 2 J. Teeth were capped with Ca(OH)2, Ca(OH)2 cement and restored with amalgam. All groups presented pulp repair. On 25th day the thickness of the formed dentin barrier was different between the groups GI and GII (p < 0.05) and between groups GI and GIII (p < 0.01). On 60th day there was difference between GI and GIII (p < 0.01). It may be concluded that, LLLT 688 nm and 785 nm accelerated dentin barrier formation and consequently pulp repair process, with best results using infrared laser 785 nm.

  9. Design of a Turbulence Generator of Medium Consistency Pulp Pumps

    Directory of Open Access Journals (Sweden)

    Hong Li

    2012-01-01

    Full Text Available The turbulence generator is a key component of medium consistency centrifugal pulp pumps, with functions to fluidize the medium consistency pulp and to separate gas from the liquid. Structure sizes of the generator affect the hydraulic performance. The radius and the blade laying angle are two important structural sizes of a turbulence generator. Starting with the research on the flow inside and shearing characteristics of the MC pulp, a simple mathematical model at the flow section of the shearing chamber is built, and the formula and procedure to calculate the radius of the turbulence generator are established. The blade laying angle is referenced from the turbine agitator which has the similar shape with the turbulence generator, and the CFD simulation is applied to study the different flow fields with different blade laying angles. Then the recommended blade laying angle of the turbulence generator is formed to be between 60° and 75°.

  10. The Role of Host-derived Dentinal Matrix Metalloproteinases in Reducing Dentin Bonding of Resin Adhesives

    OpenAIRE

    Zhang, Shan-chuan; Kern, Matthias

    2009-01-01

    Dentin matrix metalloproteinases (MMPs) are a family of host-derived proteolytic enzymes trapped within mineralized dentin matrix, which have the ability to hydrolyze the organic matrix of demineralized dentin. After bonding with resins to dentin there are usually some exposed collagen fibrils at the bottom of the hybrid layer owing to imperfect resin impregnation of the demineralized dentin matrix. Exposed collagen fibrils might be affected by MMPs inducing hydrolytic degradation, which migh...

  11. Pulp bleeding color is an indicator of clinical and histohematologic status of primary teeth.

    Science.gov (United States)

    Aaminabadi, Naser Asl; Parto, Marziyeh; Emamverdizadeh, Parya; Jamali, Zahra; Shirazi, Sajjad

    2017-06-01

    This study was carried out to investigate whether the changes in hematologic characteristic and color of pulpal bleeding is associated with clinical and histologic status of the pulp in primary teeth. A total of 211 primary molars in 103 patients, 3-6 years old, were treated. One hundred eight teeth had pulpectomy, 57 teeth had pulpotomy after pulp exposure during caries excavation, and 46 teeth had pulpotomy after accidental pulp exposure in sound dentin. After pulpal exposure, pulpal blood was collected in capillary tubes for blood color and hematologic assessment. Coronal and radicular pulp tissues were amputated for histologic assessment. Blood color was significantly darker in pulpectomy cases and samples with severe inflammation. The differences were clinically perceptible by the human eye. A significant negative correlation was detected between white blood cell (WBC) count and blood color. The counts of neutrophils and lymphocytes were significantly different between treatment groups. In addition, WBC, eosinophil, monocyte, neutrophil, and basophils counts were significantly different between degrees of inflammation in coronal pulp. Moreover, severe inflammation was higher in pulpectomy group versus pulpotomy groups. Pulp tissue calcification was also significantly higher in the pulpectomy cases. Considering the significant difference in pulpal blood color between the pulpectomy and pulpotomy cases, and between the different levels of pulpal inflammation; blood color can be a valid clinical diagnostic criterion of pulpal status and can be used for the selection of appropriate pulp treatment strategy. This study shows that pulp bleeding color can be used for selection of an appropriate pulp treatment method in primary teeth.

  12. Comparison of Calcium Hydroxide and Bioactive Glass after Direct Pulp Capping in Primary Teeth

    Directory of Open Access Journals (Sweden)

    R. Haghgoo

    2007-12-01

    Full Text Available Objective: Bioactive glass is often used as a filler material for repair of dental bone defects.In different studies osteogenic potential of this material was proved, but its dentinogenesisproperty is in doubt. The purpose of this study was to evaluate the histological pulp responses of Calcium hydroxide and Bioactive glass placed directly on exposed pulp tissues.Materials and Methods: Twenty teeth to be extracted due to orthodontic reasons were selected. These teeth were divided into two groups and treated with direct pulp capping.Calcium hydroxide was used for 10 teeth and Bioactive glass for 10 teeth. After 60 daysthe teeth were extracted and prepared for histological evaluation. Finally the data was analyzed with exact Fisher test.Results: All teeth treated with Calcium hydroxide showed inflammation. Internal resorption was seen in six teeth, abscess in five teeth and dentinal bridge in two teeth. Inflammationwas seen in three Bioactive glass samples and dentinal bridge in seven teeth, but internal resorption and abscess were not seen.Conclusion: Bioactive glass appears to be superior to Calcium hydroxide as a pulp capping agent in primary teeth.

  13. The Effect of Full Crown Preparation on Normal and Inflamed Pulp Tissue: An Animal Study

    Directory of Open Access Journals (Sweden)

    Mandana Vardkar

    2013-12-01

    Full Text Available Introduction: Full crown preparation may have adverse effects on pulp tissue. In this study, the effect of full-crown preparation on intact versus inflamed pulp tissue was studied. Methods: Fifteen healthy mature cats were randomly selected for this study. The study was performed on four canine teeth of each cat. Cats were anesthetized and then radiographs were taken from the canine teeth. Class V cavities were prepared in cat canine teeth. Soft decayed dentin was placed on the floor of cavities and sealed. After 1 month, all of the samples prepared for crown fabrication. Before crown preparation, an impression was taken in a custom tray. During crown preparation, the remnants of carious dentin were removed and undercuts were sealed by glass-ionomer. After preparation, self-cured acrylic temporary crowns were fabricated in a direct procedure and cemented permanently by glass-ionomer. One week later, teeth of the opposite jaw were prepared in a similar procedure. After 2 months, vital perfusion performed and the pulp tissue was histologically examined. Results: There was no significant difference between 4 groups, regarding to histologic status of the pulp. In healthy lower jaw, inflammation was the most frequent but in the other groups, necrosis was most frequent. Also, there was no significant difference between the upper jaw and the lower jaw groups regarding to the frequency of necrosis and inflammation. Conclusion: There is no significant difference between intact and inflamed groups regarding the frequency of necrosis and inflammation

  14. The Effect of Full Crown Preparation on Normal and Inflamed Pulp Tissue: An Animal Study

    Directory of Open Access Journals (Sweden)

    Maryam Bidar

    2013-01-01

    Full Text Available Introduction: Full crown preparation may have adverse effects on pulp tissue. In this study, the effect of full-crown preparation on intact versus inflamed pulp tissue was studied. Methods: Fifteen healthy mature cats were randomly selected for this study. The study was performed on four canine teeth of each cat. Cats were anesthetized and then radiographs were taken from the canine teeth. Class V cavities were prepared in cat canine teeth. Soft decayed dentin was placed on the floor of cavities and sealed. After 1 month, all of the samples prepared for crown fabrication. Before crown preparation, an impression was taken in a custom tray. During crown preparation, the remnants of carious dentin were removed and undercuts were sealed by glass-ionomer. After preparation, self-cured acrylic temporary crowns were fabricated in a direct procedure and cemented permanently by glass-ionomer. One week later, teeth of the opposite jaw were prepared in a similar procedure. After 2 months, vital perfusion performed and the pulp tissue was histologically examined. Results: There was no significant difference between 4 groups, regarding to histologic status of the pulp. In healthy lower jaw, inflammation was the most frequent but in the other groups, necrosis was most frequent. Also, there was no significant difference between the upper jaw and the lower jaw groups regarding to the frequency of necrosis and inflammation. Conclusion: There is no significant difference between intact and inflamed groups regarding the frequency of necrosis and inflammation

  15. A comparison between new dentinal adhesives (fifth generation) and traditional varnish in microleakage reduction of amalgam restorations in primary teeth

    OpenAIRE

    Mortazavi M. Associate Professor; Bahrololoomi Z. Assistant Professor

    2003-01-01

    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 li...

  16. Treatment of pulps in teeth affected by deep caries - A systematic review of the literature.

    OpenAIRE

    Bergenholtz, Gunnar; Axelsson, Susanna; Davidson, Thomas; Frisk, Fredrik; Hakeberg, Magnus; Kvist, Thomas; Norlund, Anders; Petersson, Arne; Portenier, Isabelle; Sandberg, Hans; Tranæus, Sofia; Mejare, Ingegerd

    2013-01-01

    BACKGROUND: This systematic review assesses the effect of methods commonly used to manage the pulp in cases of deep caries lesions, and the extent the pulp chamber remains uninfected and does not cause pulpal or periapical inflammatory lesions and associated tooth-ache over time. STUDY DESIGN: An electronic literature search included the databases PubMed, EMBASE, The Cochrane Central Register of Controlled Trials and Cochrane Reviews from January 1950 to March 2013. In addition, hand searches...

  17. MM-MTA for direct pulp capping: a histologic comparison with ProRoot MTA in rat molars.

    Science.gov (United States)

    Khalil, Issam Tanios; Sarkis, Tony; Naaman, Alfred

    2013-11-01

    To compare the histomorphological response of rat dental pulps capped with MM-MTA and ProRoot MTA at 1, 2 and 4 weeks postoperatively. Direct pulp capping with MM-MTA and ProRoot MTA, overlaid with light-cured composite resin, was performed on right and left maxillary first molars of 20 Wistar rats. Animals were killed at 1, 2 and 4 weeks postoperatively. Biopsy samples were stained and viewed by light microscopy to determine dentin bridge formation. Data were statistically evaluated with the Kruskal-Wallis test (p MTA and ProRoot MTA. The results showed no statistically significant difference between both materials at 4 weeks. Both materials produced similar responses in the pulp when used for pulp capping in intact, caries-free molars of rats.

  18. Roles of dental pulp fibroblasts in the recognition of bacterium-related factors and subsequent development of pulpitis

    Directory of Open Access Journals (Sweden)

    Tadashi Nakanishi

    2011-08-01

    Full Text Available As caries-related bacteria invade deeply into dentin and come into close proximity to the pulp, inflammatory cells (such as lymphocytes, macrophages and neutrophils infiltrate into the bacterium-invaded area and consequently pulpitis develops. Many types of cytokines and adhesion molecules are responsible for the initiation and progression of pulpitis. Dental pulp fibroblasts, a major cell type in the dental pulp, also have capacity to produce pro-inflammatory cytokines and express adhesion molecules in response to pathogen-associated molecular patterns (PAMPs, including lipopolysaccharide. The innate immune system senses microbial infection using pattern recognition receptors, such as Toll-like receptors (TLRs and nucleotide-binding oligomerization domain (NOD, for PAMPs. In this review, we summarize the roles of dental pulp fibroblasts in the recognition of invaded bacterium-related factors via TLR and NOD pathways, and the subsequent pulpal immune responses, leading to progressive pulpitis.

  19. Histo-pathological study of pulp response to a composite resin restoration with two lining materials.

    Science.gov (United States)

    Aoki, S; Ishikawa, T

    1990-11-01

    This histopathological study investigated the pulp reaction to a restoration system employing a posterior composite resin with or without the pulp protection of visible light curing calcium hydroxide composition and alpha-TCP cement lining to dentin. Black's class V cavities were prepared in 120 adult dog teeth. They were then extracted for histological examination. As a result of this study, their lining materials were found to be effective in pulp protection. To understand the pathological finding, the pH values of "Fulfil", "Universal bond", "VLC Dycal" and "Vitacemen Type II" were measured. The pH levels of "Fulfil" and "Universal Bond" were mildly acidic (4.79-5.18) before polymerization, with no subsequent changes. "VLC Dycal" was initially a strongly alkaline (11.75) and remained this condition. "Vitacemen Type II" was initially acidic (3.78), but eventually reached the milder acidity of 5.12 after 24 hours.

  20. Hard tissue regeneration capacity of apical pulp derived cells (APDCs) from human tooth with immature apex.

    Science.gov (United States)

    Abe, Shigehiro; Yamaguchi, Satoshi; Watanabe, Akihiko; Hamada, Keiichi; Amagasa, Teruo

    2008-06-20

    Recent studies indicate that dental pulp is a new source of adult stem cells. The human tooth with an immature apex is a developing organ, and the apical pulp of this tooth may contain a variety of progenitor/stem cells, which participate in root formation. We investigated the hard tissue regeneration potential of apical pulp derived cells (APDCs) from human tooth with an immature apex. APDCs cultured with a mineralization-promoting medium showed alkaline phosphatase activity in porous hydroxyapatite (HA) scaffolds. The composites of APDCs and HA were implanted subcutaneously in immunocompromised rats and harvested at 12 weeks after implantation. In histological analysis, the APDCs/HA composites exhibited bone- and dentine-like mineralized tissues in the pore areas of HA. This study suggests that the human tooth with an immature apex is an effective source of cells for hard tissue regeneration.

  1. Chamber transport

    Energy Technology Data Exchange (ETDEWEB)

    OLSON,CRAIG L.

    2000-05-17

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system.

  2. 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.

  3. The Effect of Low Level Laser Therapy on Direct Pulp Capping in Dogs

    Science.gov (United States)

    Bidar, Maryam; Moushekhian, Siavash; Gharechahi, Maryam; Talati, Ali; Ahrari, Farzaneh; Bojarpour, Maryam

    2016-01-01

    Introduction: The aim of this study was to determine the histologic effect of low level laser therapy (LLLT) with or without the use of mineral trioxide aggregate (MTA) on exposed pulp tissues of dogs. Methods: Twenty-five premolar teeth in three healthy mature dogs were randomly divided into five groups. In group 1, the pulp tissue was capped with MTA. In groups 2 and 3, before capping with MTA, the exposure site was irradiated by low power lasers at 630 nm (20 mW, 150 seconds, 7.5 J/cm2) and 810 nm (peak power 80 W, average power 50 mW, 1500 Hz, 50 seconds, 6.25 J/cm2) wavelengths, respectively. In groups 4 and 5, the exposure site was irradiated similar to that described in groups 2 and 3, but the pulp tissue was covered by gold foil instead of MTA. After 2 months, the animals were sacrificed and the samples were prepared for histologic evaluation. Results: There were differences in pulpal response and dentinal barrier formation among the study groups. The morphology of pulpal tissue and the integrity of dentinal barrier and formation of odontoblastic layer were more favorable in the first three groups. The occurrence of extensive and intense inflammation and necrosis was more frequent in groups 4 and 5. Conclusion: Under the conditions used in this study, the presence of MTA as a pulp capping material was more important than laser therapy in the success of direct pulp capping (DPC) treatment. MTA proved to be an effective material either alone or in combination with laser irradiation in vital pulp therapy. PMID:28144439

  4. Dentinogenic responses after direct pulp capping of miniature swine teeth with Biodentine.

    Science.gov (United States)

    Tziafa, Christina; Koliniotou-Koumpia, Eugenia; Papadimitriou, Serafim; Tziafas, Dimitrios

    2014-12-01

    The aim of this study was to evaluate pulpal responses after experimental direct pulp capping of mechanically exposed teeth with a new calcium silicate-based dentin replacement material. Thirty-four anterior and posterior teeth of 3 miniature swine were used. Class V or I cavities were prepared on the buccal or occlusal surfaces, respectively. Pulpal exposures were further performed using a round carbide bur 0.8 mm in diameter. Exposures were treated with white MTA Angelus (Angelus, Londrina, PR, Brazil) or Biodentine (Septodont, Saint Maur des Fosses, France), and the cavities were further restored with Biodentine. The pulpal tissue responses were histologically assessed at postoperative periods of 3 and 8 weeks. Data were statistically analyzed using the Kruskal Wallis and the Mann-Whitney U tests. Inflammatory infiltration or pulp tissue necrosis was not found in any of the specimens. All teeth showed mineralized matrix formation in the form of a complete hard tissue bridge composed of osteodentin or osteodentin followed by a discontinuous or continuous reparative dentin zone. A significantly higher thickness of the hard tissue bridge was found in the group of teeth treated with Biodentine at both 3 and 8 weeks. A number of teeth, which were under root development at the onset of the experimental procedures, exhibited ectopic pulp calcification. The application of both calcium silicate-based materials in direct contact with the mechanically exposed pulp of healthy miniature swine teeth led to pulp repair with complete hard tissue bridge formation. The thickness of hard tissue bridges was significantly higher after pulp capping with Biodentine. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Pulp response to ferric sulfate, diluted formocresol and IRM in pulpotomized primary baboon teeth.

    Science.gov (United States)

    Fuks, A B; Eidelman, E; Cleaton-Jones, P; Michaeli, Y

    1997-01-01

    This study investigated the pulp response to a 15.5 percent ferric sulfate solution (FS) and a 20 percent dilution of formocresol (DFC) in pulpotomized primary teeth of baboons, after four and eight weeks. Pulpotomies were performed in seventy-nine primary teeth of 4 baboons. After coronal pulp resection, the pulp stumps were painted with ferric sulfate for fifteen seconds, in thirty-two teeth (group 1); in another thirty-two teeth, a cotton pellet moistened with dilution of formocresol was placed over the pulp stumps for five minutes, and removed (group 2). In fifteen teeth, IRM was placed directly over the pulp stumps after hemostasis (group 3--control). The teeth of all groups were sealed with IRM, and examined for inflammatory changes under a microscope by two blinded examiners. Seventy-seven teeth were assessed. Mild or no inflammation was found in 58 percent (18/31) of the teeth of group 1, in 48 percent (15/31) of those of group 2, and in 73 percent (11/15) of those of group 3. Severe inflammation was found in 35 percent (11/31) of group 1, 29 percent (9/31) of group 2, and in 7 percent (1/15) of group 3. No statistically significant difference between the three groups was observed for degree of inflammation, periradicular or interradicular abscess or inflammatory root resorption (chi-square p > 0.05). Dentin bridges were observed in 52 percent (16/31) of the teeth in group 1, 52 percent (16/31) of those of group 2, and in 73 percent (11/15) of those of group 3. No difference was found between the experimental and control groups for the presence of dentin bridge, (p > 0.05). Ferric sulfate produced pulp responses that compared favorably to those of diluted formocresol.

  6. Antimicrobial properties and dentin bonding strength of magnesium phosphate cements.

    Science.gov (United States)

    Mestres, G; Abdolhosseini, M; Bowles, W; Huang, S-H; Aparicio, C; Gorr, S-U; Ginebra, M-P

    2013-09-01

    The main objective of this work was to assess the antimicrobial properties and the dentin-bonding strength of novel magnesium phosphate cements (MPC). Three formulations of MPC, consisting of magnesium oxide and a phosphate salt, NH4H2PO4, NaH2PO4 or a mixture of both, were evaluated. As a result of the setting reaction, MPC transformed into either struvite (MgNH4PO4·6H2O) when NH4H2PO4 was used or an amorphous magnesium sodium phosphate when NaH2PO4 was used. The MPC had appropriate setting times for hard tissue applications, high early compressive strengths and higher strength of bonding to dentin than commercial mineral trioxide aggregate cement. Bacteriological studies were performed with fresh and aged cements against three bacterial strains, Escherichia coli, Pseudomonas aeruginosa (planktonic and in biofilm) and Aggregatibacter actinomycetemcomitans. These bacteria have been associated with infected implants, as well as other frequent hard tissue related infections. Extracts of different compositions of MPC had bactericidal or bacteriostatic properties against the three bacterial strains tested. This was associated mainly with a synergistic effect between the high osmolarity and alkaline pH of the MPC. These intrinsic antimicrobial properties make MPC preferential candidates for applications in dentistry, such as root fillers, pulp capping agents and cavity liners.

  7. Biodentine-a novel dentinal substitute for single visit apexification.

    Science.gov (United States)

    Nayak, Gurudutt; Hasan, Mohammad Faiz

    2014-05-01

    Use of an apical plug in management of cases with open apices has gained popularity in recent years. Biodentine, a new calcium silicate-based material has recently been introduced as a dentine substitute, whenever original dentine is damaged. This case report describes single visit apexification in a maxillary central incisor with necrotic pulp and open apex using Biodentine as an apical barrier, and a synthetic collagen material as an internal matrix. Following canal cleaning and shaping, calcium hydroxide was placed as an intracanal medicament for 1 mon. This was followed by placement of small piece of absorbable collagen membrane beyond the root apex to serve as matrix. An apical plug of Biodentine of 5 mm thickness was placed against the matrix using pre-fitted hand pluggers. The remainder of canal was back-filled with thermoplasticized gutta-percha and access cavity was restored with composite resin followed by all-ceramic crown. One year follow-up revealed restored aesthetics and function, absence of clinical signs and symptoms, resolution of periapical rarefaction, and a thin layer of calcific tissue formed apical to the Biodentine barrier. The positive clinical outcome in this case is encouraging for the use of Biodentine as an apical plug in single visit apexification procedures.

  8. Biodentine-a novel dentinal substitute for single visit apexification

    Directory of Open Access Journals (Sweden)

    Gurudutt Nayak

    2014-05-01

    Full Text Available Use of an apical plug in management of cases with open apices has gained popularity in recent years. Biodentine, a new calcium silicate-based material has recently been introduced as a dentine substitute, whenever original dentine is damaged. This case report describes single visit apexification in a maxillary central incisor with necrotic pulp and open apex using Biodentine as an apical barrier, and a synthetic collagen material as an internal matrix. Following canal cleaning and shaping, calcium hydroxide was placed as an intracanal medicament for 1 mon. This was followed by placement of small piece of absorbable collagen membrane beyond the root apex to serve as matrix. An apical plug of Biodentine of 5 mm thickness was placed against the matrix using pre-fitted hand pluggers. The remainder of canal was back-filled with thermoplasticized gutta-percha and access cavity was restored with composite resin followed by all-ceramic crown. One year follow-up revealed restored aesthetics and function, absence of clinical signs and symptoms, resolution of periapical rarefaction, and a thin layer of calcific tissue formed apical to the Biodentine barrier. The positive clinical outcome in this case is encouraging for the use of Biodentine as an apical plug in single visit apexification procedures.

  9. Effect of an Experimental Direct Pulp-capping Material on the Properties and Osteogenic Differentiation of Human Dental Pulp Stem Cells

    Science.gov (United States)

    Yu, Fan; Dong, Yan; Yang, Yan-Wei; Lin, Ping-Ting; Yu, Hao-Han; Sun, Xiang; Sun, Xue-Fei; Zhou, Huan; Huang, Li; Chen, Ji-Hua

    2016-10-01

    Effective pulp-capping materials must have antibacterial properties and induce dentin bridge formation; however, many current materials do not satisfy clinical requirements. Accordingly, the effects of an experiment pulp-capping material (Exp) composed of an antibacterial resin monomer (MAE-DB) and Portland cement (PC) on the viability, adhesion, migration, and differentiation of human dental pulp stem cells (hDPSCs) were examined. Based on a Cell Counting Kit-8 assay, hDPSCs exposed to Exp extracts showed limited viability at 24 and 48 h, but displayed comparable viability to the control at 72 h. hDPSC treatment with Exp extracts enhanced cellular adhesion and migration according to in vitro scratch wound healing and Transwell migration assays. Exp significantly upregulated the expression of osteogenesis-related genes. The hDPSCs cultured with Exp exhibited higher ALP activity and calcium deposition in vitro compared with the control group. The novel material showed comparable cytocompatibility to control cells and promoted the adhesion, migration, and osteogenic differentiation of hDPSCs, indicating excellent biocompatibility. This new direct pulp-capping material containing MAE-DB and PC shows promise as a potential alternative to conventional materials for direct pulp capping.

  10. Effect of an Experimental Direct Pulp-capping Material on the Properties and Osteogenic Differentiation of Human Dental Pulp Stem Cells

    Science.gov (United States)

    Yu, Fan; Dong, Yan; Yang, Yan-wei; Lin, Ping-ting; Yu, Hao-han; Sun, Xiang; Sun, Xue-fei; Zhou, Huan; Huang, Li; Chen, Ji-hua

    2016-01-01

    Effective pulp-capping materials must have antibacterial properties and induce dentin bridge formation; however, many current materials do not satisfy clinical requirements. Accordingly, the effects of an experiment pulp-capping material (Exp) composed of an antibacterial resin monomer (MAE-DB) and Portland cement (PC) on the viability, adhesion, migration, and differentiation of human dental pulp stem cells (hDPSCs) were examined. Based on a Cell Counting Kit-8 assay, hDPSCs exposed to Exp extracts showed limited viability at 24 and 48 h, but displayed comparable viability to the control at 72 h. hDPSC treatment with Exp extracts enhanced cellular adhesion and migration according to in vitro scratch wound healing and Transwell migration assays. Exp significantly upregulated the expression of osteogenesis-related genes. The hDPSCs cultured with Exp exhibited higher ALP activity and calcium deposition in vitro compared with the control group. The novel material showed comparable cytocompatibility to control cells and promoted the adhesion, migration, and osteogenic differentiation of hDPSCs, indicating excellent biocompatibility. This new direct pulp-capping material containing MAE-DB and PC shows promise as a potential alternative to conventional materials for direct pulp capping. PMID:27698421

  11. Effect of dentinal tubules and resin-based endodontic sealers on fracture properties of root dentin.

    Science.gov (United States)

    Jainaen, Angsana; Palamara, Joseph E A; Messer, Harold H

    2009-10-01

    To investigate the role of dentinal tubules in the fracture properties of human root dentin and whether resin-filled dentinal tubules can enhance fracture resistance. Crack propagation in human root dentin was investigated in 200 microm thick longitudinal samples and examined by light and scanning electron microscopy. 30 maxillary premolar teeth were prepared for work of fracture (Wf) test at different tubule orientations, one perpendicular and two parallel to dentinal tubules. Another 40 single canal premolars were randomly divided into four groups of 10 each: intact dentin, prepared but unobturated canal, canal obturated with epoxy rein (AH Plus/gutta percha), or with UDMA resin sealer (Resilon/RealSeal. The samples were prepared for Wf test parallel to dentinal tubules. Wf was compared under ANOVA with statistical significance set at pcanal preparation nor obturation using epoxy- or UDMA-based resins as sealer cements substantially influenced fracture properties of root dentin, despite extensive infiltration of dentinal tubules by both sealer cements.

  12. Interactions of dentine desensitisers with human dentine: morphology and composition.

    Science.gov (United States)

    Eliades, George; Mantzourani, Maria; Labella, Roberto; Mutti, Bruna; Sharma, Deepak

    2013-07-01

    To evaluate the effect of desensitising agents on human dentine morphology and composition. Randomly assigned human coronal-dentine specimens were subjected to: (a) no treatment (smear-layer control, n=4); (b) acid etching with 6% citric acid (demineralised control, n=4); (c) treatment with desensitising agents (12 cycles of 60 s treatment with 60 s between-treatment rinsing, n=6 per agent); and (d) exposure to acidic challenge (pH 5.0 for 90 s, n=6 per agent). The tested products were: Listerine® Advanced Defence Sensitive (LADS; 1.4% potassium oxalate) mouthrinse, Colgate® Sensitive Pro-Relief™ mouthrinse, and toothpaste slurries (paste/water 1:2 wt/wt ratio) of Colgate® Sensitive Pro-Relief™ paste, Crest® Sensitive paste and Sensodyne® Repair and Protect paste. All dentine surfaces were studied by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, Raman microscopy and high vacuum scanning electron microscopy with energy-dispersive X-ray microanalysis (HV-SEM/EDX). Desensitising slurry treatments occluded tubule orifices of acid-etched dentine, creating a randomly distributed surface pattern of particle aggregates. The greatest intratubular penetration of occluding particles was found in dentine treated with LADS. The atomic ratios of Ca/N and Ca/P, and the mineral/matrix ratios increased after toothpaste-slurry treatments compared with the acid-etched dentine. However, the acidic challenge removed most surface precipitates and further demineralised these substrates. Before the acidic challenge, the surface features were least affected in specimens treated with Sensodyne® Repair and Protect. After the acidic challenge, the sub-surface occlusion features were least affected in specimens treated with LADS. Although most tested products achieved occlusion of dentinal tubules and provided evidence of mineral deposits, the deposit formed by LADS demonstrated the greatest resistance to acidic challenge, which simulates intra

  13. Adhesion to bovine dentin--surface characterization.

    Science.gov (United States)

    Ruse, N D; Smith, D C

    1991-06-01

    X-ray photo-electron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) were used to characterize the dentin surface, to determine the effects of different pre-conditioning procedures on the elemental composition of the dentin surface, and to investigate the interaction between dentin and a dentin bonding agent (ScotchBond) by studying the changes in the elemental composition of dentin as a result of the interaction. Scanning electron microscopy (SEM) was used to characterize sample surface morphology, which was then correlated with surface elemental composition. The results showed that: (a) the elemental composition of the smear layer was similar to that of the underlying dentin; (b) cleaning with hydrogen-peroxide did not produce any modification in the elemental composition of the dentin surface; and (c) acid-etching led to an almost complete demineralization of the dentin, leaving behind an organic-rich surface. The results suggest that bonding systems that use acid-etching as a pre-conditioning procedure should be based on agents able to interact with the organic components of dentin, since bonding agents that rely on a chelation-to-calcium reaction are unlikely to be successful. The investigation of the interaction between the bonding agent and dentin led to a postulated adhesive-bonding reaction mechanism and suggested a partially cohesive failure in the bonding agent during fracturing of a dentin-bonding-agent-bonded assembly.

  14. Glycerol Salicylate-based Pulp-Capping Material Containing Portland Cement.

    Science.gov (United States)

    Portella, Fernando Freitas; Collares, Fabrício Mezzomo; Santos, Paula Dapper; Sartori, Cláudia; Wegner, Everton; Leitune, Vicente Castelo Branco; Samuel, Susana Maria Werner

    2015-01-01

    The purpose of this study was to evaluate the water sorption, solubility, pH and ability to diffuse into dentin of a glycerol salicylate-based, pulp-capping cement in comparison to a conventional calcium hydroxide-based pulp capping material (Hydcal). An experimental cement was developed containing 60% glycerol salicylate resin, 10% methyl salicylate, 25% calcium hydroxide and 5% Portland cement. Water sorption and solubility were determined based on mass changes in the samples before and after the immersion in distilled water for 7 days. Material discs were stored in distilled water for 24 h, 7 days and 28 days, and a digital pHmeter was used to measure the pH of water. The cement's ability to diffuse into bovine dentin was assessed by Raman spectroscopy. The glycerol salicylate-based cement presented higher water sorption and lower solubility than Hydcal. The pH of water used to store the samples increased for both cements, reaching 12.59 ± 0.06 and 12.54 ± 0.05 after 7 days, for Hydcal and glycerol salicylate-based cements, respectively. Both cements were able to turn alkaline the medium at 24 h and sustain its alkalinity after 28 days. Hydcal exhibited an intense diffusion into dentin up to 40 µm deep, and the glycerol salicylate-based cement penetrated 20 µm. The experimental glycerol salicylate-based cement presents good sorption, solubility, ability to alkalize the surrounding tissues and diffusion into dentin to be used as pulp capping material.

  15. Revitalization of an Immature Permanent Mandibular Molar with a Necrotic Pulp Using Platelet-Rich Fibrin: A Case Report

    Science.gov (United States)

    Shoba, Krishnamma; Aman, Shibu; Bharkavi, Srinivasan Kumar Indu

    2016-01-01

    Any insult to the pulp during its development causes cessation of dentin formation and root growth. Pulpal status and degree of root development are the decisive factors in the treatment approach. Various treatment options have been tried like surgery with root-end sealing, calcium hydroxide–apexification, placement of apical plug and regenerative endodontic procedures to induce apexogenesis. An ideal scenario for a necrosed tooth with immature root would be continued root development coupled with regeneration of pulp tissue. We report a case, where revitalization was done using Platelet-Rich Fibrin (PRF) as a scaffold in immature mandibular molar tooth. PMID:28050518

  16. Purple sweet potato (Ipomea Batatas P. as dentin hypersensitivity desensitization gel

    Directory of Open Access Journals (Sweden)

    Chariza Hanum Mayvita Iskandar

    2015-12-01

    Full Text Available Background: Dentin hypersensitivity is a short sharp sense of pain in the teeth when exposed to excitatory stimulus. A total of 74% of world population experiencing dentin hypersensitivity. Home treatment topical desensitization is rarely found in Indonesia. The use of dentrifice is less practical because it must be done with regular brushing. Indonesia has abundant natural resources, one of which is purple sweet potato. Purple sweet potato (Ipomea Batatas P. has highest potasium ions compared to other foodstuffs. Potassium ions can be a solution of dentin hypersensitivity by temporary blocking the suffix pulp nerve impulses. Purpose: The research objective was to determine the effectiveness of the 10% purple sweet potato extract gel of the dental pain threshold score. Method: An experimental study carried out by dental pain threshold score measurements using vitality tester into the teeth with gum recession. Samples included 32 respondents with a single blind and pre-post test control group design. They were divided into treatment group and negative control group. Paired T-test and Wilcoxon were used as data analysis. Result: The results showed dental pain threshold score increasing either in treatment group and negative control, although not as significant as in the treatment group. Conclusion: 10% purple sweet potato extract gel containing potassium ions is able to reduce the pain of dentin hypersensitivity.

  17. Effects of Non-Collagenous Proteins, TGF-β1, and PDGF-BB on Viability and Proliferation of Dental Pulp Stem Cells

    Science.gov (United States)

    Tabatabaei, Fahimeh Sadat

    2016-01-01

    ABSTRACT Objectives The dentin matrix servers as a reservoir of growth factors, sequestered during dentinogenesis. The aim of this study was to assess the viability and proliferation of dental pulp stem cells in the presence of dentin matrix-derived non-collagenous proteins and two growth factors; platelet-derived growth factor BB and transforming growth factor beta 1. Material and Methods The dental pulp cells were isolated and cultured. The dentin proteins were extracted and purified. The MTT assay was performed for assessment of cell viability and proliferation in the presence of different concentrations of dentin proteins and growth factors during 24 - 72 h post-treatment. Results The cells treated with 250 ng/mL dentin proteins had the best viability and proliferation ability in comparison with other concentrations (P < 0.05). The MTT assay demonstrated that cells cultured with 5 ng/mL platelet-derived growth factor BB had the highest viability at each time point as compared to other groups (P < 0.05). However, in presence of platelet-derived growth factor BB alone and in combination with transforming growth factor beta 1 and dentin proteins (10 ng/mL), significant higher viability was seen at all time points (P < 0.05). The least viability and proliferation at each growth factor concentration was seen in cells treated with combination of transforming growth factor beta 1 and dentin proteins at 72 h (P < 0.05). Conclusions The results indicated that the triple combination of growth factors and matrix-derived non-collagenous proteins (especially at 10 ng/mL concentration) has mitogenic effect on dental pulp stem cells. PMID:27099698

  18. Effects of Non-Collagenous Proteins, TGF-β1, and PDGF-BB on Viability and Proliferation of Dental Pulp Stem Cells

    Directory of Open Access Journals (Sweden)

    Fahimeh Sadat Tabatabaei

    2016-03-01

    Full Text Available Objectives: The dentin matrix servers as a reservoir of growth factors, sequestered during dentinogenesis. The aim of this study was to assess the viability and proliferation of dental pulp stem cells in the presence of dentin matrix-derived non-collagenous proteins and two growth factors; platelet-derived growth factor BB and transforming growth factor beta 1. Material and Methods: The dental pulp cells were isolated and cultured. The dentin proteins were extracted and purified. The MTT assay was performed for assessment of cell viability and proliferation in the presence of different concentrations of dentin proteins and growth factors during 24 - 72 h post-treatment. Results: The cells treated with 250 ng/mL dentin proteins had the best viability and proliferation ability in comparison with other concentrations (P < 0.05. The MTT assay demonstrated that cells cultured with 5 ng/mL platelet-derived growth factor BB had the highest viability at each time point as compared to other groups (P < 0.05. However, in presence of platelet-derived growth factor BB alone and in combination with transforming growth factor beta 1 and dentin proteins (10 ng/mL, significant higher viability was seen at all time points (P < 0.05. The least viability and proliferation at each growth factor concentration was seen in cells treated with combination of transforming growth factor beta 1 and dentin proteins at 72 h (P < 0.05. Conclusions: The results indicated that the triple combination of growth factors and matrix-derived non-collagenous proteins (especially at 10 ng/mL concentration has mitogenic effect on dental pulp stem cells.

  19. The permeability of dentine from bovine incisors in vitro.

    Science.gov (United States)

    Tagami, J; Tao, L; Pashley, D H; Horner, J A

    1989-01-01

    The permeability of coronal dentine was investigated by measuring the hydraulic conductance of dentine discs. Reductions in dentine thickness from the enamel side of disc resulted in a greater increase in permeability than reductions from the pulpal side. Scanning electron microscopy revealed fewer dentinal tubules with smaller diameters in superficial dentine than in deep dentine. The permeability of coronal incisor bovine dentine is six to eight times less than that of unerupted coronal human third molar dentine but similar to that of human root dentine.

  20. 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

  1. Dentinal candidiasis in cancer patients.

    Science.gov (United States)

    Damm, D D; Neville, B W; Geissler, R H; White, D K; Drummond, J F; Ferretti, G A

    1988-01-01

    Two examples of an unusual presentation of oropharyngeal candidiasis in cancer patients are offered. The light and scanning electron microscopic appearances of candidiasis involving the dentin of teeth are described. The potential significance of recognition of this form of candidiasis in cancer patients is discussed.

  2. Effect of two desensitizing agents on dentin permeability in vitro

    Science.gov (United States)

    ISHIHATA, Hiroshi; KANEHIRA, Masafumi; FINGER, Werner J.; TAKAHASHI, Hidekazu; TOMITA, Makoto; SASAKI, Keiichi

    2017-01-01

    Abstract Objective The aim of this in vitro study was to investigate the effect of two desensitizing agents and water on hydraulic conductance in human dentin. Material and Methods GLUMA Desensitizer PowerGel (GLU) contains glutaraldehyde (GA) and 2-hydroxyethyl methacrylate (HEMA), and Teethmate Desensitizer (TD) is a powder comprising tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA) that is mixed with water. Deionized water was used as a negative control (CTR). Thirty discs with a thickness of 1.2 mm were cut from the coronal dentin of the third molars and cleaned with 0.5 M EDTA (pH 7.4). After being mounted in a split-chamber device, the discs were pressurized with water at 1 kPa and 3 kPa in order to measure flow rates with a highly sensitive micro-flow sensor and to calculate hydraulic conductance as a baseline value (BL). Following the application of GLU, TD, and CTR (n=10), hydraulic conductance was remeasured with intermittent storage in water after 15 min, 1 d, 1 w, and 1 m. Reduction in permeability (PR%) was calculated from hydraulic conductance. Data were statistically analyzed using nonparametric methods (α<0.05). Representative discs were inspected by SEM. Results PR% for GLU and TD were 30-50% 15 min and 1 m after their application. Post hoc tests indicated that PR% of CTR was significantly greater than those of GLU and TD at all time points tested. The PR% of GLU and TD were not significantly different. SEM examinations showed noncollapsed collagen meshes at the tubular entrances after GLU, and crystalline precipitates occluding the tubular orifices after TD, whereas CTR specimens showed typical patterns of etched dentin. Conclusions The present study on hydraulic conductance in dentin discs treated with two chemically different desensitizing agents and water as a control demonstrated that both products may be characterized as effective. PMID:28198974

  3. Stage-specific effects of fibroblast growth factor 2 on the differentiation of dental pulp cells.

    Science.gov (United States)

    Sagomonyants, Karen; Mina, Mina

    2014-01-01

    Dentinogenesis is a complex and multistep process, which is regulated by various growth factors, including members of the fibroblast growth factor (FGF) family. Both positive and negative effects of FGFs on dentinogenesis have been reported, but the underlying mechanisms of these conflicting results are still unclear. To gain a better insight into the role of FGF2 in dentinogenesis, we used dental pulp cells from various transgenic mice, in which fluorescent protein expression identifies cells at different stages of odontoblast differentiation. Our results showed that the continuous exposure of pulp cells to FGF2 inhibited mineralization and revealed both the stimulatory and inhibitory effects of FGF2 on the expression of markers of dentinogenesis and various transgenes. During the proliferation phase of in vitro growth, FGF2 increased the expression of markers of dentinogenesis and the percentages of dentin matrix protein 1/green fluorescent protein (DMP1-GFP)-positive functional odontoblasts and dentin sialophosphoprotein (DSPP)-Cerulean-positive odontoblasts. Additional exposure to FGF2 during the differentiation/mineralization phase of in vitro growth decreased the extent of mineralization and the expression of markers of dentinogenesis and of the DMP1-GFP and DSPP-Cerulean transgenes. Recovery experiments showed that the inhibitory effects of FGF2 on dentinogenesis were related to the blocking of the differentiation of cells into mature odontoblasts. These observations together showed the stage-specific effects of FGF2 on dentinogenesis by dental pulp cells, and they provide critical information for the development of improved treatments for vital pulp therapy and dentin regeneration.

  4. Promotion of Dental Pulp Cell Migration and Pulp Repair by a Bioceramic Putty Involving FGFR-mediated Signaling Pathways.

    Science.gov (United States)

    Zhang, J; Zhu, L X; Cheng, X; Lin, Y; Yan, P; Peng, B

    2015-06-01

    Mineral trioxide aggregate is the currently recommended material of choice for clinical pulp repair despite several disadvantages, including handling inconvenience. Little is known about the signaling mechanisms involved in bioceramic-mediated dental pulp repair-particularly, dental pulp cell (DPC) migration. This study evaluated the effects of iRoot BP Plus, a novel ready-to-use nanoparticulate bioceramic putty, on DPC migration in vitro and pulp repair in vivo, focusing on possible involvement of fibroblast growth factor receptor (FGFR)-related signaling, including mitogen-activated protein kinase and Akt pathways. Treatment with iRoot BP Plus extracts enhanced horizontal and vertical migration of DPCs, which was comparable with the effects induced by mineral trioxide aggregate extracts. The DPCs exposed to iRoot BP Plus extracts demonstrated no evident apoptosis. Importantly, treatment with iRoot BP Plus extracts resulted in rapid activation of FGFR, p38 mitogen-activated protein kinase, extracellular signal-regulated kinase (ERK) 1/2, c-Jun-N-terminal kinase (JNK), and Akt signaling in DPCs. Confocal immunofluorescence staining revealed that iRoot BP Plus stimulated focal adhesion formation and stress fiber assembly in DPCs, in addition to upregulating the expression of focal adhesion molecules, including p-focal adhesion kinase, p-paxillin, and vinculin. Moreover, activation of FGFR, ERK, JNK, and Akt were found to mediate the upregulated expression of focal adhesion molecules, stress fiber assembly, and enhanced DPC migration induced by iRoot BP Plus. Consistent with the in vitro results, we observed induction of homogeneous dentin bridge formation and expression of p-focal adhesion kinase, p-FGFR, p-ERK 1/2, p-JNK, and p-Akt near injury sites by iRoot BP Plus in an in vivo pulp repair model. These data demonstrate that iRoot BP Plus can promote DPC migration and pulp repair involving the FGFR-mediated ERK 1/2, JNK, and Akt pathways. These findings provide

  5. Effect of phytic acid etchant on the structural stability of demineralized dentine and dentine bonding.

    Science.gov (United States)

    Kong, Kalyan; Islam, Md Sofiqul; Nassar, Mohannad; Hiraishi, Noriko; Otsuki, Masayuki; Yiu, Cynthia K Y; Tagami, Junji

    2015-08-01

    This study examined the effect of phytic acid (IP6) in stabilizing the morphology of dentine collagen network and resin-dentine bonding. Dentine beams were fully demineralized with 10% phosphoric acid (PA) or 1% IP6 (pH 1.2). PA-demineralized beams were divided into three groups: (a) no further treatment (control), (b) treatment with 5% glutaraldehyde (GA) for 1 h and (c) treatment with 1% IP6 (pH 7) for 1 h. IP6-demineralized beams received no further treatment. The beams were then subjected to ultimate tensile strength (UTS) testing. Dentine micromorphology evaluation was performed using a field-emission scanning electron microscope (FE-SEM). Dentine disks were etched with 35% PA for 15 s or 1% IP6 for 30s. PA-etched dentine disks were divided into three groups as (a), (b) and (c) as for UTS testing, but the treatment with GA or IP6 was done in 1min. For microtensile bond strength (µTBS) testing, flat dentine surfaces etched with PA or IP6 were blot-dried (wet dentine) or air-dried for 10s (dry dentine) and bonded with an etch-and-rinse adhesive followed by composite build-up. IP6-demineralized dentine showed significantly higher UTS, when compared to PA-demineralized dentine. GA and IP6 significantly improved UTS of PA-demineralized dentine. FE-SEM observation revealed that dentine collagen network was preserved by GA and IP6. No significant difference in µTBS was found between the wet and dry IP6-etched dentine groups. IP6 etching showed a structural stabilizing effect on demineralized dentine matrix and produced good resin-dentine bonding, regardless of dentine moistness or dryness. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Pulp tissue inflammation and angiogenesis after pulp capping with transforming growth factor β1

    Directory of Open Access Journals (Sweden)

    Sri Kunarti

    2008-06-01

    Full Text Available In Restorative dentistry the opportunity to develop biomemitic approaches has been signalled by the possible use of various biological macromolecules in direct pulp capping reparation. The presence of growth factors in dentin matrix and the putative role indicating odontoblast differentiation during embryogenesis has led to the examination on the effect of endogenous TGF-β1. TGF-β1 is one of the Growth Factors that plays an important role in pulp healing. The application of exogenous TGF-β1 in direct pulp capping treatment should be experimented in fibroblast tissue in-vivo to see the responses of inflammatory cells and development of new blood vessels. The increase in food supplies always occurs in the process of inflammation therefore the development of angiogenesis is required to fulfil the requirement. This in-vivo study done on orthodontic patients indicated for premolar extraction between 10–15 years of age. A class V cavity preparation was created in the buccal aspect 1 mm above gingival margin to pulp exposure. The cavity was slowly irrigated with saline solution and dried using a sterile small cotton pellet. The sterile absorbable collagen membrane was applied and soaked in 5 ml TGF-β1. It was covered by a Teflon pledge to separate from Glass Ionomer Cement restoration. Evaluation was performed on day 7; 14; and 21. All samples were histopathologycally examined and data was statistically analysed using one way ANOVA and Dunnet T3.There were no inflammatory symptoms in clinical examination on both Ca(OH2 and TGF-β1, but they increased the infiltration of inflammatory cells on histopathological examination. There were no significant differences (p > 0.05 between Ca(OH2 and TGF-β1 in inflammation cell and significant differences (p < 0.05 in angiogenesis on day 7 and 14. There were no significant differences (p > 0.05 in inflammation cell with in TGF-β1 groups and significant differences (p < 0.05 with in Ca(OH2 groups on day 7

  7. Effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding.

    Science.gov (United States)

    Secilmis, Asli; Bulbul, Mehmet; Sari, Tugrul; Usumez, Aslihan

    2013-01-01

    The neodymium/yttrium-aluminum-garnet (Nd/YAG) laser has been suggested to repair broken prostheses in the mouth. This study investigated the effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding. Three intact human maxillary molars were prepared for full-veneer crown. For each tooth, dentin thicknesses in mesiobuccal cusp was 2, 3, or 4 mm. Twenty dies were duplicated from each of the prepared teeth. For metal copings with 0.5-mm thickness, wax patterns were prepared with dip wax technique directly onto each of dies. All patterns were sprued and invested. The castings were made using a nickel-chromium alloy (Nicromed Premium, Neodontics). A hole with 0.5-mm diameter was prepared on the mesiobuccal cusp of each crown. The Nd/YAG laser (9.85 W; 1 Hz repetition rate; fluence, 1.230 J/cm(2); Fidelis Plus 3, Fotona) was used for welding with or without air cooling (n = 10). The temperature rise was measured in pulpal chamber with a J-type thermocouple wire that was connected to a data logger. Differences between start and highest temperature reading were taken, and temperature rise values were compared using two-way analysis of variance and Tukey's honestly significant difference tests (α = .05). Pulpal temperature rise varied significantly depending on the dentin thickness and air cooling (p cooling group induced significantly the highest temperature increases. There were no significant differences between 2- and 3-mm dentin thicknesses groups (p > 0.05); however, pulpal temperature rise was the lowest for 4-mm dentin thickness group (p cooling was used in 2-mm dentin thickness group. Laser welding on base metal castings with Nd/YAG laser can be applied with air cooling to avoid temperature rises known to adversely affect pulpal health when dentin thickness is 2 or 3 mm.

  8. A Review on Biodentine, a Contemporary Dentine Replacement and Repair Material

    Science.gov (United States)

    Malkondu, Özlem; Kazandağ, Meriç Karapinar; Kazazoğlu, Ender

    2014-01-01

    Biodentine is a calcium-silicate based material that has drawn attention in recent years and has been advocated to be used in various clinical applications, such as root perforations, apexification, resorptions, retrograde fillings, pulp capping procedures, and dentine replacement. There has been considerable research performed on this material since its launching; however, there is scarce number of review articles that collates information and data obtained from these studies. Therefore, this review article was prepared to provide the reader with a general picture regarding the findings about various characteristics of the material. The results of a PubMed search were classified and presented along with some critical comments where necessary. The review initially focuses on various physical properties of the material with subheadings and continues with biocompatibility. Another section includes the review of studies on Biodentine as a vital pulp treatment material and the article is finalized with the summary of some case reports where the material has been used. PMID:25025034

  9. 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.

  10. The effect of exposure duration of self etch dentin bonding on the toxicity of human gingival fibroblast of cell culture

    Directory of Open Access Journals (Sweden)

    Sri Lestari

    2008-06-01

    Full Text Available Self etch dentin bonding created to make light easily activate the application of composite resin on tooth surface. The monomer content has acid effect that could irritate tooth pulp. The purpose of this study was to evaluate the effect of light exposure duration of self etch dentin bonding on toxicity of human gingival fibroblast of cell culture by MTT assay. Self etch dentin bonding was used as on experimental unit and the sample was exposed by visible light curing in different duration: 10, 20, 30 seconds and immerged in artificial saliva in pH 7 for 24 hours. 100 µl artificial saliva was exposed to human gingival fibroblast of cell culture 20.000 cells/100 µl RPMI for 24 hours. Toxicity was evaluated by MTT assay, optical density was measured using 550 nm spectrophotometer. The data was analyzed using Kruskal Wallis in 5% degree of significance. The result showed that increasing exposure duration (10, 20, 30 seconds of self etch dentin bonding will reduce the toxicity of human gingival fibroblast of cell culture. It is concluded that 30 seconds-exposure of self etch dentin bonding will reduce the toxicity of human gingival fibroblast of cell culture.

  11. Doriot Climatic Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers are two, 60-feet long, 11-feet high, 15-feet wide chambers that are owned and operated by NSRDEC. The Doriot Climatic Chambers are among...

  12. Contraction stress in dentin adhesives bonded to dentin.

    Science.gov (United States)

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

    2006-08-01

    Adhesives cured under constrained conditions develop contraction stresses. We hypothesized that, with dentin as a bonding substrate, the stress would reach a maximum, followed by a continuous decline. Stress development was determined with a tensilometer for two total-etch systems and two systems with self-etching primers. The adhesives were placed in a thin layer between a glass plate and a flat dentin surface pretreated with phosphoric acid or self-etching primer. After an initial maximum shortly after light-curing, the stress decreased dramatically for the total-etch systems (70%) and, to a lesser extent, for the adhesives with self-etching primers (30%). The greater stress decrease for the total-etch systems was ascribed to water and/or solvents released into the adhesives from the fully opened dentinal tubules by the pulling/sucking action of the contraction stress. This happened less with the adhesives with self-etching primers, where the tubules remained mainly closed.

  13. Directed Energy Anechoic Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

  14. The critical apical diameter to obtain regeneration of the pulp tissue after tooth transplantation, replantation, or regenerative endodontic treatment.

    Science.gov (United States)

    Laureys, Wim G M; Cuvelier, Claude A; Dermaut, Luc R; De Pauw, Guy A M

    2013-06-01

    Regeneration of pulp-like tissue in the pulp chamber after tooth transplantation, replantation, or in regenerative endodontic treatment is only possible if the apical foramen is open. According to the literature, the success of regeneration decreases considerably if the foramen is smaller than 1 mm when measured on radiographs. The aim of this study was to study histologically the relation between the width of the apical foramen and regeneration of tissue in the pulp chamber after autotransplantation. Fifteen single-rooted mature teeth of 3 adult beagle dogs were used. All experimental teeth were extracted and underwent apicoectomy. The teeth were photographed from the apical side, and the width of the foramen was calculated. The foramen width ranged from 0.24-1.09 mm. All teeth were replanted in infraocclusion. The observation period was 90 days after transplantation. The 10 teeth with the smallest apical diameter, ranging between 0.24 and 0.53 mm, showed vital tissue in at least one third of the pulp chamber. The 6 most successful teeth showing vital tissue in the entire pulp chamber had an apical diameter between 0.32 and 0.65 mm, and 80% of the experimental teeth with a diameter varying between 1.09 and 0.31 mm showed vital tissue in at least one third of the pulp chamber 90 days after transplantation. The size of the apical foramen seems not to be the all decisive factor for successful revascularization and ingrowth of new tissue after transplantation. The minimum width of the apical foramen has not been determined, but a size smaller than 1 mm does not prevent revascularization and ingrowth of vital tissue. In this animal study an apical foramen of 0.32 mm did not prevent ingrowth of new tissue in two-thirds of the pulp chamber 90 days after transplantation. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Accelerated coffee pulp composting.

    Science.gov (United States)

    Sánchez, G; Olguín, E J; Mercado, G

    1999-02-01

    The effect of two abundant, easily available and very low-cost agro-industrial organic residues, i.e., filter cake from the sugar industry and poultry litter, on the composting stabilization time of coffee pulp and on the quality of the produced compost, was evaluated. Piles of one cubic meter were built and monitored within the facilities of a coffee processing plant in the Coatepec region of the State of Veracruz, Mexico. Manual aeration was carried out once a week. A longer thermophilic period (28 days) and a much lower C/N ratio (in the range of 6.9-9.1) were observed in the piles containing the amendments, as compared to the control pile containing only coffee pulp (14 days and a C/N ratio of 14.4, respectively). The maximum assimilation rate of the reducing sugars was 1.6 g kg-1 d-1 (from 7.5 to 5.3%) during the first two weeks when accelerators were present in the proportion of 20% filter cake plus 20% poultry litter, while they accumulated at a rate of 1.2 g kg-1 d-1 (from 7.4 to 9.13%) during the same period in the control pile. The best combination of amendments was 30% filter cake with 20% poultry litter, resulting in a final nitrogen content as high as 4.81%. The second best combination was 20% filter cake with 10% poultry litter, resulting in a compost which also contained a high level of total nitrogen (4.54%). It was concluded that the use of these two residues enhanced the composting process of coffee pulp, promoting a shorter stabilization period and yielding a higher quality of compost.

  16. Frameshift mutations in dentin phosphoprotein and dependence of dentin disease phenotype on mutation location

    NARCIS (Netherlands)

    P. Nieminen; L. Papagiannoulis-Lascarides; J. Waltimo-Siren; P. Ollila; S. Karjalainen; S. Arte; J. Veerkamp; V. Tallon Walton; E. Chimenos Küstner; T. Siltanen; H. Holappa; P.L. Lukinmaa; S. Alaluusua

    2011-01-01

    We describe results from a mutational analysis of the region of the dentin sialophosphoprotein (DSPP) gene encoding dentin phosphoprotein (DPP) in 12 families with dominantly inherited dentin diseases. In eight families (five mutations in the N-terminal third of DPP), the clinical and radiologic fea

  17. Multi-factoriality of dentine hypersensitivity

    OpenAIRE

    Stojšin Ivana; Petrović Ljubomir; Stojanac Igor; Drobac Milan

    2008-01-01

    Introduction. Dentine hypersensitivity has been defined as a sharp, short pain arising from exposed dentin in response to stimuli typically thermal, evaporative tactile, osmoticor, chemical and which cannot be ascribed to any other form of dental defect or pathology. Prevalence. The most affected patients range in age from 20 to 40. The following teeth tend to be most sensitive: cuspids, premolars and incisors, location-concentrated on the facial surface. Morphological bases of dentine hypers...

  18. IMMEDIATE HUMAN PULP RESPONSE TO ETHANOL-WET BONDING TECHNIQUE

    Science.gov (United States)

    Scheffel, Débora Lopes Salles; Sacono, Nancy Tomoko; Ribeiro, Ana Paula Dias; Soares, Diana Gabriela; Basso, Fernanda Gonçalves; Pashley, David Henry; Costa, Carlos Alberto de Souza; Hebling, Josimeri

    2016-01-01

    Objective To evaluate the short-term response of human pulps to ethanol-wet bonding technique associated with an etch-and-rinse adhesive system. Methods Deep class V cavities were prepared on the buccal surface of 17 sound premolars scheduled for extraction for orthodontics. The teeth were assigned into three groups: Ethanol-wet bonding (G1), water-wet bonding (G2) and calcium hydroxide (G3, control). Two teeth were used as intact control. After acid-etching, the cavities from G1 were filled with 100% ethanol for 60s and blot-dried before the application of Single Bond 2. In G2, the cavities were filled with distilled water for 60s previously to adhesive application and in G3, the cavity floor was lined with calcium hydroxide before etching and bonding. All cavities were restored with resin composite. The teeth were extracted 48h after the clinical procedures. From each tooth 6 μm-thick serial sections were obtained and stained with hematoxylin and eosin (H/E) and Masson's trichrome. Bacteria microleakage was assessed using Brown & Brenn. All sections were blindly evaluated and scored for five histological features. Results Mean remaining dentin thickness was 463±65μm (G1); 425±184μm (G2); and 348±194μm (G3). Similar pulp reactions followed ethanol- or water-wet bonding techniques. Slight inflammatory responses and disruption of the odontoblast layer related to the cavity floor were seen in all groups. Stained bacteria were not detected in any cavities. Normal pulp tissue was observed in G3 except for one case. Conclusions After 48 h, ethanol-wet bonding technique applied on deep cavities prepared in vital teeth does not increase pulpal damage compared to water-wet bonding technique. Clinical significance Ethanol-wet bonding has been considered an experimental technique that may increase resin-dentin bond durability. This study reported the in vivo response of human pulp tissue when 100% ethanol was applied previously to an etch-and-rinse simplified adhesive

  19. ALKALINE PULP OF CORN STALKS

    Institute of Scientific and Technical Information of China (English)

    M.SarwarJalaan; M.AN.Russell; S.A.N.Shamim; A.I.Mostafa; Md.AbdulQuaiyyum

    2004-01-01

    Pulping of corn stalks was studied in soda,soda-anthraquinone (AQ), kraft and kraft-AQprocesses. The time, temperature and alkaliconcentration were varied in soda process. In respectto kappa number and pulp yield, 1 hour cooking at1400C in 14% alkali were best conditions for cornstalks pulping. Pulp yield was increased by 5.5% andkappa number was reduced by 4.4 points with anaddition of 0.05% AQ in the soda liquor. Breakinglength was better in soda-AQ process than sodaprocess but tear strength was inferior. In the kraftprocess, pulp yield was increased with increasingsulphidity and decreasing active alkali. Theeffectiveness of AQ in the low and high sulphiditykraft process was studied. Results showed that AQwas more effective in low sulphidity than highsulphidity. Strength properties in kraft processeswere better than the soda and soda-AQ processes.

  20. Evaluation of reparative dentin formation of ProRoot MTA, Biodentine and BioAggregate using micro-CT and immunohistochemistry.

    Science.gov (United States)

    Kim, Jia; Song, Young-Sang; Min, Kyung-San; Kim, Sun-Hun; Koh, Jeong-Tae; Lee, Bin-Na; Chang, Hoon-Sang; Hwang, In-Nam; Oh, Won-Mann; Hwang, Yun-Chan

    2016-02-01

    The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA.

  1. Evaluation of reparative dentin formation of ProRoot MTA, Biodentine and BioAggregate using micro-CT and immunohistochemistry

    Directory of Open Access Journals (Sweden)

    Jia Kim

    2016-02-01

    Full Text Available Objectives The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA. Materials and Methods Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP. Results On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p < 0.05. On H&E staining, ProRoot MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. Conclusions Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA.

  2. NEWSPRINT FROM SODA BAGASSE PULP IN ADMIXTURE WITH HARDWOOD CMP PULP

    Directory of Open Access Journals (Sweden)

    Seed Rahman Jafari Petroudy

    2011-05-01

    Full Text Available Based on global research and experiences producing newsprint from bagasse, the possibility of using bagasse chemical pulp in the furnish of local mill-made mixed hardwood CMP pulp was studied at laboratory scale, for making newsprint. Bagasse soda chemical pulp at digester yield of about 47% was bleached to about 60% brightness by single stage hydrogen peroxide. The effects of using up to 30% bagasse chemical pulp in a blend with hardwood CMP pulp, with or without softwood kraft pulp, were studied. The results showed that superior hand sheet properties could be achieved by using bagasse chemical pulp; in comparison with main mill pulp furnish (83% hardwood CMP pulp and 17% imported long fiber pulp. In other words, by using bagasse chemical pulp in a blend with local mill made hardwood CMP pulp, acceptable newsprint could be made with considerable reduction in the consumptions of hardwood species and softwood reinforcing kraft pulp.

  3. Dentinogenic Specificity in the Preclinical Evaluation of Vital Pulp Treatment Strategies: A Critical Review

    Directory of Open Access Journals (Sweden)

    Dimitrios Tziafas

    2015-11-01

    Full Text Available Reviews on the clinical performance of vital pulp treatment strategies and capping materials repeatedly showed an insufficient grade of evidence concerning their therapeutic validity. The biological mechanisms underlying the regenerative potential of pulp-dentin complex have attracted much attention during the last two decades, since new pulp treatment modalities have been designed and tested at the preclinical level. It has been recognized that evaluation should be based on the specific ability of therapeutic interventions to signal recruitment and differentiation of odontoblast-like cells forming a matrix in a predentin-like pattern, rather than uncontrolled hard tissue deposition in a scar-like form. The aim of the present article was to critically review data from histological experimental studies on pulp capping, published during the last 7 decades. A comprehensive literature search covering the period from 1949 to 2015 was done using the Medline/Pubmed database. Inclusion of a study was dependent on having sufficient data regarding the type of capping material used and the unit of observation (human permanent tooth in vivo or animal permanent dentition; primary teeth were excluded. The post-operatively deposited matrix was categorized into three types: unspecified, osteotypic, or dentin-like matrix. One hundred fifty-two studies were included in the final evaluation. Data from the present systematic review have shown that only 30.2% of the 152 experimental histological pulp capping studies described the heterogenic nature of the hard tissue bridge formation, including osteotypic and tubular mineralized tissue. Structural characteristics of the new matrix and the associated formative cells were not provided by the remaining 106 studies. Analysis showed that more careful preclinical evaluation with emphasis on the evidence regarding the dentinogenic specificity of pulp therapies is required. It seems that selection of appropriate vital pulp

  4. Advances in regeneration of dental pulp--a literature review.

    Science.gov (United States)

    Ajay Sharma, Lavanya; Sharma, Ajay; Dias, George J

    2015-05-01

    This review summarizes the biological response of dentin-pulp complexes to a variety of stimuli and responses to current treatment therapies and reviews the role of tissue engineering and its application in regenerative endodontics. An electronic search was undertaken based on keywords using Medline/PubMed, Embase, Web of Science and Ovid database resources up to March 2012 to identify appropriate articles, supplemented by a manual search using reference lists from relevant articles. Inclusion criteria were mainly based on different combinations of keywords and restricted to articles published in English language only. Biological approaches based on tissue engineering principles were found to offer the possibility of restoring natural tooth vitality, with distinct evidence that regeneration of lost dental tissues is possible. Studies to formulate an ideal restorative material with regenerative properties, however, are still under way. Further research with supporting clinical studies is required to identify the most effective and safe treatment therapy. © 2013 Wiley Publishing Asia Pty Ltd.

  5. PULP FIBER SIZE CHARACTERIZATION

    Institute of Scientific and Technical Information of China (English)

    Shijie Liu

    2004-01-01

    Pulp fiber length distribution characterization has been examined in this study. Because of the fiber morphology: slender in shape, fiber size distribution characterization is a very difficult task. Traditional technique involves separation of the particles by size,such as Bauer-McNett fiber classifier, and measuring the weight fractions. The particle fractions obtained may or may not reflect the desired size classification.On the other hand, the more recent technique through optical measurement of fiber length is limited by its inability to measure the mass of the particle fractions.Therefore, not only the two techniques fail to generate identical results, either one was accepted to be of better value. Pure hardwood kraft, softwood kraft, and their mixture samples have been measured for their fiber length distributions using an optical fiber quality analyzer: FQA. The data obtained from FQA are extensively studied to investigate more reliable way of representing the fiber length data and thus examining the viable route for measuring the fiber size distributions. It has been found that the fiber length averaged length 11 is a viable indicator of the average pulp fiber length. The fiber size fraction and/or distribution can be represented by the fiber "length" fractions.

  6. PULP FIBER SIZE CHARACTERIZATION

    Institute of Scientific and Technical Information of China (English)

    ShijieLiu

    2004-01-01

    Pulp fiber length distribution characterization hasbeen examined in this study. Because of the fibermorphology: slender in shape, fiber size distributioncharacterization is a very difficult task. Traditionaltechnique involves separation of the particles by size,such as Bauer-McNett fiber classifier, and measuringthe weight fractions. Themay or may not reflect theparticle fractions obtaineddesired size classification.On the other hand, the more recent technique throughoptical measurement of fiber length is limited by itsinability to measure the mass of the particle fractions.Therefore, not only the two techniques fail togenerate identical results, either one was accepted tobe of better value. Pure hardwood kraft, softwoodkraft, and their mixture samples have been measuredfor their fiber length distributions using an opticalfiber quality analyzer: FQA. The data obtained fromFQA are extensively studied to investigate morereliable way of representing the fiber length data andthus examining the viable route for measuring thefiber size distributions. It has been found that thefiber length averaged length 1~ is a viable indicator ofthe average pulp fiber length. The fiber size fractionand/or distribution can be represented by the fiber"length" fractions.

  7. Pulp tissue dissolution capacity of QMix 2in1 irrigation solution

    Science.gov (United States)

    Arslan, Dilara; Guneser, Mehmet Burak; Kustarci, Alper; Er, Kursat; Siso, Seyda Herguner

    2015-01-01

    Objective: The aim of this study was to evaluate the tissue dissolution efficacy of four root canal irrigation solutions (sodium hypochlorite [NaOCl], chlorhexidine gluconate [CHX], Octenidine [OCT], and QMix 2in1) on bovine pulp tissue. Materials and Methods: Fifty bovine pulp tissue samples, each weighing 6.55 mg, were prepared and randomly divided into four experimental groups and one control group (n = 10) according to the dissolution irrigants used: (1) 5.25% NaOCl group; (2) 2% CHX group; (3) OCT group; (4) QMix 2in1 group; and (5) control group (saline solution). These samples were then placed into special bovine dentin reservoir models and immersed for 1 h with each test solution (0.1 mL of each) at room temperature. The pulp samples were then blotted dry and weighed again. The percentage of weight loss was calculated. Statistically analyzed with one-way analysis of variance and post-hoc Tukey tests (P = 0.05). Results: Saline solution did not dissolve the bovine pulp tissue. All groups, except OCT, dissolved pulp samples more effectively than the control group (P < 0.05). The highest tissue dissolution was observed in 5.25% NaOCl group (P < 0.05). No statistically significant difference was found between the tissue-dissolving effect between QMix 2in1 and those of 2% CHX. Conclusions: Within the limitations of this in vitro study, NaOCl exhibited the best tissue-dissolving effect out of all solutions tested. CHX and QMix 2in1 were able to dissolve pulp tissue but less than NaOCl. OCT and saline solutions could not exhibit significantly tissue-dissolving effectiveness. This study shown that QMix 2in1 has little capacity to dissolve pulp tissue therefore used alone is not sufficient for this purpose. PMID:26430374

  8. Chapter 6: Prehydrolysis Pulping with Fermentation Coproducts

    Science.gov (United States)

    T.H. Wegner; C.J. Houtman; A.W. Rudie; B.L. Illman; P.J. Ince; E.M. Bilek; T.W. Jeffries

    2013-01-01

    Although the term “integrateed biorefinery” is new, the concept has long been familiar to the pulp and paper industry, where processes include biomass boilers providing combined heat and power, and byproducts of pulping include turpentine, fatty acids and resin acids. In the dominant kraft (or sulfate) pulping process, dissolved lignin and chemicals from the pulp...

  9. The antimicrobial peptide LL37 induces the migration of human pulp cells: a possible adjunct for regenerative endodontics.

    Science.gov (United States)

    Kajiya, Mikihito; Shiba, Hideki; Komatsuzawa, Hitoshi; Ouhara, Kazuhisa; Fujita, Tsuyoshi; Takeda, Katsuhiro; Uchida, Yuushi; Mizuno, Noriyoshi; Kawaguchi, Hiroyuki; Kurihara, Hidemi

    2010-06-01

    The antimicrobial peptide LL37 has multiple functions, such as the induction of angiogenesis and migration. Pulp cell migration is a key phenomenon in the early stage of pulp-dentin complex regeneration. In this study, we examined the effect of LL37 on the migration of human pulp (HP) cells. HP cells at the sixth passage were exposed to LL37. The migration of HP cells was assessed by a wound-healing assay. The phosphorylation of epidermal growth factor receptor (EGFR) and c-Jun N-terminal kinase (JNK) was analyzed by immunoblotting. LL37 as well as heparin binding (HB)-EGF, which is an agonist of EGFR, induced HP cell migration. LL37 increased the level of phosphorylated EGFR. An anti-EGFR antibody, an EGFR tyrosine kinase inhibitor, and a JNK inhibitor abolished the migration induced by both LL37 and HB-EGF. Furthermore, the two peptides increased the levels of phosphorylated JNK. LL37 activates EGFR and JNK to induce HP cell migration, and it may contribute to enhancing the regeneration of pulp-dentin complexes. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  10. Effects of orthodontic forces on pulp tissue

    Directory of Open Access Journals (Sweden)

    Pinandi Sri Pudyani

    2006-09-01

    Full Text Available Numerous researches on pulp tissue changes caused by orthodontic forces have been performed, among others are: pulp angiogenesis, pulp tissue respiration rate, alkaline phosphatase and aspartate aminotransferase enzyme activities; micro vascular response inside the pulp and the effect of dental movement i.e. extrusion, intrusion, and torque. The result is still controversial, as some researchers claim that orthodontic force has a negative effect, others deny by saying there is no such effect on pulp tissue.

  11. Pulp regeneration after non-infected and infected necrosis, what type of tissue do we want? A review.

    Science.gov (United States)

    Andreasen, Jens O; Bakland, Leif K

    2012-02-01

    Regeneration (revitalization) of infected necrotic pulp tissue has been an important issue in endodontics for more than a decade. Based on a series of case reports, there appears to be evidence that new soft tissue can enter the root canal with a potential for subsequent hard tissue deposition resulting in a narrowing of the root canal. Very little is presently known about the exact nature of this tissue growing into the canal and how it may behave in the long term. In the case of regeneration of necrotic non-infected pulp tissue, a series of clinical and histological studies have shown that such events may take place in four variants: (i) Revascularization of the pulp with accelerated dentin formation leading to pulp canal obliteration. This event has a good long-term prognosis. (ii) Ingrowth of cementum and periodontal ligament (PDL). The long-term prognosis for this event is not known. (iii) Ingrowth of cementum, PDL, and bone. The long-term prognosis is only partly known, but cases developing an internal ankylosis have been described. (iv) Ingrowth of bone and bone marrow is a rare phenomenon and the long-term prognosis does not appear to be good. Based on current knowledge, expectations with respect to pulp regeneration (revitalization) of infected necrotic dental pulps are difficult to predict; more information than now available is needed before procedures for pulpal regeneration can be routinely recommended with a predictable long-term prognosis. © 2011 John Wiley & Sons A/S.

  12. Clinical and radiographic comparison of indirect pulp treatment using light-cured calcium silicate and mineral trioxide aggregate in primary molars: A randomized clinical trial

    OpenAIRE

    Navya P Menon; Balagopal R Varma; Sureshkumar Janardhanan; Parvathy Kumaran; Arun Mamachan Xavier; Bhat Sangeetha Govinda

    2016-01-01

    Aim: To clinically and radiographically evaluate the reparative dentin formation in indirect pulp treatment (IPT) using mineral trioxide aggregate (MTA) and light cured calcium silicate (TheraCal) in primary molars over a period of 6 months. Materials and Methods: A clinical trial on IPT on 43 primary molars in 21 patients between the age of 4–7 years, divided into two groups: 22 teeth in MTA group and 21 in TheraCal group. Measurement of the variation in dentin thickness was done on the digi...

  13. Pulpal responses to bacterial contamination following dentin bridging beneath hard-setting calcium hydroxide and self-etching adhesive resin system.

    Science.gov (United States)

    Kitasako, Yuichi; Ikeda, Masaomi; Tagami, Junji

    2008-04-01

    To evaluate the pulp healing to bacterial contamination beneath a hard-setting calcium hydroxide (DY: Dycal, L.D. Caulk Co.) and a self-etching adhesive resin (2V: Clearfil Liner Bond 2V, Kuraray Medical Inc.) following dentin bridge formation. Class V cavities were prepared on 30 monkey teeth, and the pulps were exposed with a carbide bur through the cavity floor. Each exposed pulp was capped with either DY or 2V. The cavities were restored with a hybrid resin composite. The resin composite was removed at 180 days after capping, and then cavities were left open to the oral environment for 2 weeks to obtain bacteria contamination DY (BDY) and 2V (B2V; n = 10). A non-bacterial-contaminated group capped with DY was used as control. After bacterial challenges, inflammatory cell infiltration, incidence and differentiation of dentin bridges were evaluated histologically. There were significant differences in the presence of inflammatory cell infiltration among all groups (P < 0.05). No moderate or severe inflammatory reaction was found in Group DY. Group BDY showed moderate or severe inflammatory cell infiltration in 50%, and showed four necrotic specimens. Although no statistically significant difference was found in the formation and differentiation of dentin bridges among all groups, tunnel defects in dentin bridges were detected in 70% (DY), 80% (BDY), and 50% (B2V). Group B2V showed a significantly lower presence of inflammatory cell infiltration than Group BDY (P < 0.05). Bonding agent is supposed to seal the exposure site, and the remaining bonding agent on the cavities was effective as the barrier in the dentin bridges after bacterial challenges.

  14. Fluid mechanics in dentinal microtubules provides mechanistic insights into the difference between hot and cold dental pain.

    Science.gov (United States)

    Lin, Min; Luo, Zheng Yuan; Bai, Bo Feng; Xu, Feng; Lu, Tian Jian

    2011-03-23

    Dental thermal pain is a significant health problem in daily life and dentistry. There is a long-standing question regarding the phenomenon that cold stimulation evokes sharper and more shooting pain sensations than hot stimulation. This phenomenon, however, outlives the well-known hydrodynamic theory used to explain dental thermal pain mechanism. Here, we present a mathematical model based on the hypothesis that hot or cold stimulation-induced different directions of dentinal fluid flow and the corresponding odontoblast movements in dentinal microtubules contribute to different dental pain responses. We coupled a computational fluid dynamics model, describing the fluid mechanics in dentinal microtubules, with a modified Hodgkin-Huxley model, describing the discharge behavior of intradental neuron. The simulated results agreed well with existing experimental measurements. We thence demonstrated theoretically that intradental mechano-sensitive nociceptors are not "equally sensitive" to inward (into the pulp) and outward (away from the pulp) fluid flows, providing mechanistic insights into the difference between hot and cold dental pain. The model developed here could enable better diagnosis in endodontics which requires an understanding of pulpal histology, neurology and physiology, as well as their dynamic response to the thermal stimulation used in dental practices.

  15. Dentinal innervation of impacted human third molars.

    Science.gov (United States)

    Lilja, J; Fagerberg-Mohlin, B

    1984-12-01

    Five totally impacted third molars were studied in the transmission electron microscope for the presence of nervous structures in the dentin before eruption. In contradiction to earlier studies available, nervous structures were found in the predentin and the dentin of the impacted third molars in different parts of the crown and also in the predentin of the root.

  16. Raman spectra of human dentin mineral

    NARCIS (Netherlands)

    Tsuda, H; Ruben, J; Arends, J

    1996-01-01

    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

  17. 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.

  18. Intra-pulp temperature increase of equine cheek teeth during treatment with motorized grinding systems: influence of grinding head position and rotational speed

    Science.gov (United States)

    2014-01-01

    Background In equine practice, teeth corrections by means of motorized grinding systems are standard procedure. The heat resulting from that treatment may cause irreparable damage to the dental pulp. It has been shown that a 5.5°C temperature rise may cause severe destruction in pulp cells. Hence, the capability to continuously form secondary dentine is lost, and may lead, due to equine-typical occlusal tooth abrasion, to an opening of the pulp cavity. To obtain reliable data on the intra-pulp increase in temperature during corrective treatments, equine cheek teeth (CT) were modified in a way (occlusal surface smoothed, apical parts detached, pulp horns standardized) that had been qualified in own former published studies. All parameters influencing the grinding process were standardized (force applied, initial temperatures, dimensions of pulp horns, positioning of grinding disk, rotational speed). During grinding experiments, imitating real dental treatments, the time span for an intra-pulp temperature increase of 5.5°C was determined. Results The minimum time recorded for an intra-pulp temperature increase of 5.5°C was 38 s in mandibular CT (buccal grinding, 12,000 rpm) and 70 s in maxillary CT (flat occlusal grinding, 12,000 rpm). The data obtained showed that doubling the rotational speed of the disk results in halving the time span after which the critical intra-pulp temperature increase in maxillary CT is reached. For mandibular CT, the time span even drops by two thirds. Conclusion The use of standardized hypsodont CT enabled comparative studies of intra-pulp heating during the grinding of occlusal tooth surfaces using different tools and techniques. The anatomical structure of the natural vital hypsodont tooth must be kept in mind, so that the findings of this study do not create a deceptive sense of security with regard to the time-dependent heating of the native pulp. PMID:24559121

  19. Pulp response to collagen and glutaraldehyde in pulpotomized primary teeth of baboons.

    Science.gov (United States)

    Fuks, A B; Jones, P C; Michaeli, Y; Bimstein, E

    1991-01-01

    This investigation assessed histologically the pulp tissue reaction to glutaraldehyde (GA) and to a commercial collagen preparation in pulpotomized primary teeth of baboons. One hundred and eighty-eight primary teeth were pulpotomized; in half of them inflammation was induced prior to the treatment. The teeth were divided into five groups: in three of them GA was used as a pulp dressing and applied for 1 min (group 1), 5 min (group 2), or mixed into the paste (group 3); collagen was used in group 4 and in group 5 (control) IRM was placed directly over the pulp stumps. Follow-up times were two, eight, and 24 weeks. Total necrosis was observed only in the collagen group. Partial necrosis and severe inflammation also were seen mainly in this group, and when the GA was incorporated into the paste. Slight to moderate inflammation was evident in all groups two and eight weeks postoperatively; however, 78% of the teeth of group 2 (GA 5 min) were inflammation-free after 24 weeks. Partial dentin bridges were seen in 92% of the teeth of the control group, in 82% of group 2, and 50% each of groups 1 and 3 eight weeks postoperatively. Dentin bridges were present in only 4% of the collagen group. After 24 weeks, all the teeth in group 2 and 83% of group 1 had dentin bridges. We conclude that Zyderm (Colagen Corp. Palo Alto, CA) led to unacceptable results, 5 min application of GA presented the best healing response, and GA 1 min and IRM also were satisfactory.

  20. Platelet Rich Fibrin in the revitalization of tooth with necrotic pulp and open apex

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    Vasundara Yayathi Shivashankar

    2012-01-01

    Full Text Available Regeneration of pulp-dentin complex in an infected necrotic tooth with an open apex is possible if the canal is effectively disinfected. The purpose of this case report is to add a regenerative endodontic case to the existing literature about using Platelet Rich Fibrin (PRF. A nine year old boy who accidently broke his immature maxillary central incisor tooth, developed pulpal necrosis with apical periodontitis. After the access cavity preparation, the canal was effectively irrigated with 20 ml of 5.25% sodium hypochlorite solution and 10ml of 0.2% chlorhexidine solution and dried with paper points. Triple antibiotic paste was placed inside the canal and left for 21 days. 12 ml of whole blood was drawn from the patient′s right antecubital vein and centrifuged for 10 minutes to obtain the Choukroun′s PRF. After the removal of the triple antibiotic paste, the PRF was placed into the canal till the level of cementoenamel junction and 3mm of grey MTA was placed directly over the PRF clot. The setting of MTA was confirmed 3 days later and the tooth was double sealed with GIC and Composite restoration.After 1 year the clinical examination revealed negative responses to percussion and palpation tests. The tooth responded positively to cold and electric pulp tests. Radiographic examination revealed continued thickening of the dentinal walls, root lengthening, regression of the periapical lesion and apical closure. On the basis of the results obtained in our case report we conclude that revitalization of necrotic infected immature tooth is possible under conditions of total canal disinfection and PRF is an ideal biomaterial for pulp-dentin complex regeneration.

  1. EDTA soluble chemical components and the conditioned medium from mobilized dental pulp stem cells contain an inductive microenvironment, promoting cell proliferation, migration, and odontoblastic differentiation.

    Science.gov (United States)

    Kawamura, Rei; Hayashi, Yuki; Murakami, Hiroshi; Nakashima, Misako

    2016-05-25

    The critical challenge in tissue engineering is to establish an optimal combination of stem cells, signaling morphogenetic molecules, and extracellular matrix scaffold/microenvironment. The extracellular matrix components of teeth may be reconstituted as an inductive microenvironment in an ectopic tooth transplantation bioassay. Thus, the isolation and identification of the chemical components of the inductive microenvironment in pulp/dentin regeneration will accelerate progress towards the goal of tissue engineering of the tooth. The teeth demineralized in 0.6 M hydrochloric acid were sequentially extracted by 4.0 M guanidine hydrochloride (GdnHCl), pH 7.4, and 0.5 M ethylenediaminetetraacetic acid (EDTA), pH 7.4. The extracted teeth were transplanted into an ectopic site in severe combined immunodeficiency (SCID) mice with mobilized dental pulp stem cells (MDPSCs). The unextracted tooth served as a positive control. Furthermore, the soluble components for the inductive microenvironment, the GdnHCl extracts, or the EDTA extracts together with or without MDPSC conditioned medium (CM) were reconstituted systematically with autoclaved teeth in which the chemical components were completely inactivated and only the physical microenvironment was preserved. Their pulp/dentin regenerative potential and angiogenic potential were compared 28 days after ectopic tooth transplantation by histomorphometry and real-time RT-PCR analysis. Expression of an odontoblastic marker, enamelysin, and a pulp marker, thyrotropin-releasing hormone degrading enzyme (TRH-DE), was lower, and expression of a periodontal cell marker, anti-asporin/periodontal ligament-associated protein 1 (PLAP-1), was higher in the transplant of the EDTA-extracted teeth compared with the GdnHCl-extracted teeth. The autoclaved teeth reconstituted with the GdnHCl extracts or the EDTA extracts have weak regenerative potential and minimal angiogenic potential, and the CM significantly increased this potential

  2. Cysteine Cathepsins in Human Carious Dentin

    Science.gov (United States)

    Nascimento, F.D.; Minciotti, C.L.; Geraldeli, S.; Carrilho, M.R.; Pashley, D.H.; Tay, F.R.; Nader, H.B.; Salo, T.; Tjäderhane, L.; Tersariol, I.L.S.

    2011-01-01

    Matrix metalloproteinases (MMPs) are important in dentinal caries, and analysis of recent data demonstrates the presence of other collagen-degrading enzymes, cysteine cathepsins, in human dentin. This study aimed to examine the presence, source, and activity of cysteine cathepsins in human caries. Cathepsin B was detected with immunostaining. Saliva and dentin cysteine cathepsin and MMP activities on caries lesions were analyzed spectrofluorometrically. Immunostaining demonstrated stronger cathepsins B in carious than in healthy dentin. In carious dentin, cysteine cathepsin activity increased with increasing depth and age in chronic lesions, but decreased with age in active lesions. MMP activity decreased with age in both active and chronic lesions. Salivary MMP activities were higher in patients with active than chronic lesions and with increasing lesion depth, while cysteine cathepsin activities showed no differences. The results indicate that, along with MMPs, cysteine cathepsins are important, especially in active and deep caries. PMID:21248362

  3. NEWSPRINT FROM SODA BAGASSE PULP IN ADMIXTURE WITH HARDWOOD CMP PULP

    OpenAIRE

    Seed Rahman Jafari Petroudy; Hossein Resalati Mail; pejman Rezayati Charani Mail

    2011-01-01

    Based on global research and experiences producing newsprint from bagasse, the possibility of using bagasse chemical pulp in the furnish of local mill-made mixed hardwood CMP pulp was studied at laboratory scale, for making newsprint. Bagasse soda chemical pulp at digester yield of about 47% was bleached to about 60% brightness by single stage hydrogen peroxide. The effects of using up to 30% bagasse chemical pulp in a blend with hardwood CMP pulp, with or without softwood kraft pulp, were st...

  4. Temporal and spatial expression of c-jun and jun-B proto-oncogenes in pulp cells involved with reparative dentinogenesis after cavity preparation of rat molars.

    Science.gov (United States)

    Kitamura, C; Kimura, K; Nakayama, T; Terashita, M

    1999-02-01

    c-jun and jun-B are nuclear proto-oncogenes induced by growth factors such as bone morphogenetic proteins (BMPs). These gene products enhance the expression of many genes, including osteocalcin and collagen types, indicating that c-jun and jun-B play important roles in the cell differentiation process. It is also known that BMPs affect the differentiation of pulp cells to odontoblast-like cells during reparative dentinogenesis, but little is known about the transcriptional regulation of genes in cells associated with reparative dentinogenesis. In this study, we examined the expression of c-jun and jun-B in pulp cells during reparative dentinogenesis after cavity preparation of rat molars by in situ hybridization. In rat tooth germs, c-jun and jun-B were co-expressed in the odontoblastic lineage. In rat adult molars, c-jun was expressed in the odontoblast layer, but the jun-B expression was absent in all pulp cells. After cavity preparation, we found that c-jun and jun-B were coexpressed in pulp cells underneath cavities. During the early phase of reparative dentinogenesis, levels of c-jun and jun-B greatly increased in pulp cells within and around the reparative dentin matrix formed adjacent to the cavity floor. Fourteen days after cavity preparation, c-jun and jun-B were expressed only in pulp cells lining the irregular surface of the thick reparative dentin. These results suggest that c-jun and jun-B may play important roles both in physiological and in reparative dentinogenesis; in particular, the limited distribution of the jun-B expression suggests a specific role of jun-B only in cells involved with the active formation of the dentin matrix during primary and reparative dentinogenesis.

  5. Histopathologic Responses of the Dental Pulp to Calcium-Enriched Mixture (CEM) and Mineral Trioxide Aggregate (MTA) in Diabetic and Non-Diabetic Rats.

    Science.gov (United States)

    Madani, Zahra Sadat; Haddadi, Azam; Mesgarani, Abbas; Seyedmajidi, Maryam; Mostafazadeh, Amrollah; Bijani, Ali; Ashraphpour, Manouchehr

    2014-01-01

    Diabetes mellitus is a chronic disease which affects the healing ability of the pulp and periodontium. The aim of the present study was to assess the histopathologic response of dental pulp to pulp capping using MTA or CEM cement in diabetic rats. Thirty two Wistar male rats aged between 8 and 10 weeks (weight: 200-250g) were divided into two groups of diabetic (n=16) and healthy (n=16) animals and then subdivided into MTA and CEM subgroups. In each group, 10 MTA treated, 10 CEM treated and 12 intact (without any intervention) teeth were analyzed. Intact teeth were considered as a baseline inflammation control. Then, class I cavity was made in the maxillary first molars teeth with pinpoint pulpal exposure. Either MTA or CEM cement was then placed over exposed pulp as pulp capping agent and the cavities were restored using resin- modified glass ionomer cement. Both teeth of rats in subgroups remained intact without any intervention. After four weeks, the rats were sacrificed and the teeth were subjected to histological evaluation in terms of inflammation intensity, dentin bridge formation and dentin bridge continuity. The CEM cement treated diabetic rats exhibited a significant higher inflammatory response when compared to healthy control group (P=0.004) whereas, MTA treated diabetic rats did not exhibit a significant higher inflammatory response in comparison to healthy controls. There was no significant difference between MTA and CEM cement in the induction of dentin bridge formation in diabetic and healthy controls. This preliminary study suggests that MTA is a superior dental material than CEM cement for pulp therapy in subjects with diabetes.

  6. ON THE STIFFNESS OF DEMINERALIZED DENTIN MATRICES

    Science.gov (United States)

    Ryou, Heonjune; Turco, Gianluca; Breschi, Lorenzo; Tay, Franklin R.; Pashley, David H.; Arola, Dwayne

    2015-01-01

    Resin bonding to dentin requires the use of self-etching primers or acid etching to decalcify the surface and expose a layer of collagen fibrils of the dentin matrix. Acid-etching reduces the stiffness of demineralized dentin from approximately 19 GPa to 1 MPa, requiring that it floats in water to prevent it from collapsing during bonding procedures. Several publications show that crosslinking agents like gluteraladehyde, carbodiimide or grape seed extract can stiffen collagen and improve resin-dentin bond strength. Objective The objective was to assess a new approach for evaluating the changes in stiffness of decalcified dentin by polar solvents and a collagen cross-linker. Methods Fully demineralized dentin beams and sections of etched coronal dentin were subjected to indentation loading using a cylindrical flat indenter in water, and after treatment with ethanol or ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). The stiffness was measured as a function of strain and as a function of loading rate from 1 to 50 µm/sec. Results At a strain of 0.25% the elastic modulus of the fully demineralized dentin was approximately 0.20 MPa. It increased to over 0.90 MPa at strains of 1%. Exposure to ethanol caused an increase in elastic modulus of up to four times. Increasing the loading rate from 1 to 50 µm/sec caused an increase in the apparent modulus of up to three times in both water and ethanol. EDC treatment caused increases in the stiffness in fully demineralized samples and in acid-etched demineralized dentin surfaces in situ. Significance Changes in the mechanical behavior of demineralized collagen matrices can be measured effectively under hydration via indentation with cylindrical flat indenters. This approach can be used for quantifying the effects of bonding treatments on the properties of decalcified dentin after acid etching, as well as to follow the loss of stiffness over time due to enzymatic degradation. PMID:26747822

  7. Mesenchymal Stem Cells Derived from Dental Pulp: A Review

    Directory of Open Access Journals (Sweden)

    Edgar Ledesma-Martínez

    2016-01-01

    Full Text Available The mesenchymal stem cells of dental pulp (DPSCs were isolated and characterized for the first time more than a decade ago as highly clonogenic cells that were able to generate densely calcified colonies. Now, DPSCs are considered to have potential as stem cell source for orthopedic and oral maxillofacial reconstruction, and it has been suggested that they may have applications beyond the scope of the stomatognathic system. To date, most studies have shown that, regardless of their origin in third molars, incisors, or exfoliated deciduous teeth, DPSCs can generate mineralized tissue, an extracellular matrix and structures type dentin, periodontal ligament, and dental pulp, as well as other structures. Different groups worldwide have designed and evaluated new efficient protocols for the isolation, expansion, and maintenance of clinically safe human DPSCs in sufficient numbers for various therapeutics protocols and have discussed the most appropriate route of administration, the possible contraindications to their clinical use, and the parameters to be considered for monitoring their clinical efficacy and proper biological source. At present, DPSC-based therapy is promising but because most of the available evidence was obtained using nonhuman xenotransplants, it is not a mature technology.

  8. Do different dentin tubular patterns of primary molars affect the bond strength of total-etching and self-etching adhesive systems?

    Directory of Open Access Journals (Sweden)

    Henrique Castilhos Ruschel

    2014-01-01

    Full Text Available Aims: To evaluate the tensile bond strength of self-etching and total-etching adhesive systems to the different dentin surfaces of primary molars and to analyze the resin-dentin interface. Methodology: In this in vitro study, dentin samples 35 to 65% distant from the pulp (intermediate dentin were obtained from buccal and lingual surfaces at the middle third of the crown of fi rst and second primary molars. Dentin surfaces were prepared with 400 and 600-grit silicon carbide paper. Three adhesive systems (Prime & Bond NT, AdheSE and Clear fi l SE Bond were tested on the fi rst and second primary molar surfaces (n=15; inverted truncated cones of resin composite with a 2.0 mm bonding diameter were built. After 24 hour storage in distilled water at 37°C, the specimens were submitted to the tensile bond strength test. To analyze the resin-dentin interface under scanning electron microscopy, samples were prepared with the same three adhesive systems (n=5. Results: No differences between fi rst and second primary molar dentin substrates could be observed in mean bond strength values (ANOVA; p>0.05. The following mean bond strength values (MPa were obtained: 15.65±3.70 (Prime & Bond NT, 19.47±7.09 (AdheSE and 17.14 ±5.35 (Clear fi l SE Bond. There were no statistically signi fi cant differences between the self-etching adhesive systems. The presence of hybrid a layer and tags were observed in all groups. Conclusions: Contemporary adhesive systems showed similar behaviors on both dentin tubular surfaces of primary molars. Follow-up studies of the clinical performance of these materials are needed.

  9. Analysis of the soluble human tooth proteome and its ability to induce dentin/tooth regeneration.

    Science.gov (United States)

    Chun, So Young; Lee, Hyo Jung; Choi, Young Ae; Kim, Kyung Min; Baek, Sang Heum; Park, Hyo Sang; Kim, Jae-Young; Ahn, Jung-Mo; Cho, Je-Yeol; Cho, Dong-Woo; Shin, Hong-In; Park, Eui Kyun

    2011-01-01

    While the soluble proteins of human teeth consist of various extracellular matrix and bioactive proteins, they have not yet been characterized fully. Moreover, the role they play in tooth regeneration is not clear. Analysis of the soluble proteins in human teeth by liquid chromatography-mass spectrometry revealed 147 different ethylenediaminetetraacetic acid-soluble tooth proteins (ESTPs). Of these, 29 had not been shown previously to be present in human teeth. To determine their effect on the in vitro responses of dental pulp stem cells (DPSCs), DPSCs were cultured in ESTP-coated culture plates and three-dimensional scaffolds. The ESTPs significantly enhanced DPSC odontoblast differentiation and mineralization in vitro, but had only partial effect on bone marrow stem cells or adipose tissue stem cells. To test the effect of ESTPs on in vivo dentin and tooth formation, mouse embryonic tooth-forming primordia and xenogenic murine apical bud epithelium/human DPSC composites were treated with ESTPs before implantation under the renal capsule of ICR mice. ESTP treatment promoted the formation of morphologically normal teeth by the tooth-forming primordium regions and enhanced the development of a regular and large dentin structure by the composites. These observations suggest that human ESTPs contain dentinogenic proteins and can promote dentin and tooth formation.

  10. Pulp response to bases and cavity depths.

    Science.gov (United States)

    Lee, S J; Walton, R E; Osborne, J W

    1992-04-01

    In cavities of ferret canines, preparation depth and bases were compared as to their effect on odontoblasts and to rate of dentin formation. These were measured by injecting 3H-proline at 0, 20 and 40 days post-preparation. Odontoblast activity was determined by label density in each band; inter-band distances indicated the amount of dentin formed. Correlations were by Pearson's coefficient. The following were determined: 1) cavity depth (remaining dentin thickness) was the major factor in odontoblast response and in dentin formation; deeper cavities suppressed odontoblasts with less subsequent dentin formation at all time periods; 2) basing materials had little effect on odontoblast activity or on the rate of dentin formation. An exception was in deep cavities, with Ca(OH)2 showing more label; this activity was temporary with no increased dentin formation; 3) there was no evidence of a "rebound" response.

  11. Gene Expression Profiling and Molecular Signaling of Dental Pulp Cells in Response to Tricalcium Silicate Cements: A Systematic Review.

    Science.gov (United States)

    Rathinam, Elanagai; Rajasekharan, Sivaprakash; Chitturi, Ravi Teja; Martens, Luc; De Coster, Peter

    2015-11-01

    Signaling molecules and responding dental pulp stem cells are the 2 main control keys of dentin regeneration/dentinogenesis. The aim of this study was to present a systematic review investigating the gene expression of various dental pulp cells in response to different variants of tricalcium silicate cements. A systematic search of the literature was performed by 2 independent reviewers followed by article selection and data extraction. Studies analyzing all sorts of dental pulp cells (DPCs) and any variant of tricalcium silicate cement either as the experimental or as the control group were included. A total of 39 articles were included in the review. Among the included studies, ProRoot MTA (Dentsply, Tulsa Dental, OK) was the most commonly used tricalcium silicate cement variant. The extracellular signal regulated kinase/mitogen-activated protein kinase pathway was the most commonly activated pathway to be identified, and similarly, dentin sialophosphoprotein osteocalcin dentin matrix acidic phosphoprotein 1, alkaline phosphatase, bone sialoprotein, osteopontin, type I collagen, and Runx2 were the most commonly expressed genes in that order of frequency. Biodentine (Septodont Ltd, Saint Maur des Faussés, France), Bioaggregate (Innovative Bioceramix, Vancouver, BC, Canada), and mineral trioxide aggregate stimulate the osteogenic/odontogenic capacity of DPCs by proliferation, angiogenesis, and biomineralization through the activation of the extracellular signal regulated kinase ½, nuclear factor E2 related factor 2, p38, c-Jun N-terminal kinase mitogen-activated protein kinase, p42/p44 mitogen-activated protein kinase, nuclear factor kappa B, and fibroblast growth factor receptor pathways. When DPCs are placed into direct contact with tricalcium silicate cements, they show higher levels of gene activation, which in turn could translate into more effective pulpal repair and faster and more predictable formation of reparative dentin. Copyright © 2015 American

  12. EVALUATION OF CONDITION OF THE PULP BY PULSE OXIMETRY.

    Directory of Open Access Journals (Sweden)

    Dimitar Kosturkov

    2015-12-01

    Full Text Available Purpose: To conduct pulse oximetry (PO and electric pulp test (EPT on intact frontal teeth in clinically healthy patients aged between 18 and 25 years who do not have periodontal disease. Material/Methods: To achieve the aim 1058 teeth of 31 patients were studied. The following inclusion criteria for the study were set: 1. Age – 18-25 years. 2. Clinically healthy patient, who does not have any systemic diseases, do not take any medicine systematically. 3. Intact frontal teeth – without carious lesions, restorations or root canal treatment. 4. Lack of periodontal disease. Research was conducted with a pulse oximeter Contec™ - CMS60D and a custom made probe holder. Results: Average values obtained by pulse oximetry in upper jaw vary between 83% and 85%. In lower jaw – between 82% and 85%. 99% is the maximum and 48% is the minimum registered value. The average value of the measurement of all the teeth is 84%. The average saturation measured on the small finger of the right hand of the patient is 98%. The average value of EPT for all teeth is 4 μA. The maximum measured value is 20 μA, and the minimum - 1 μA. Conclusions: 1. Adequate study of the pulp includes two complementary methods – electric pulp test (evaluation of innervation and pulse oximetry (assessment of pulp microcirculation. 2. Teeth that are larger in size have larger values of PO and EPT, which is in direct relation to the size of their pulp chamber. 3. The total saturation, measured in the little finger of the right hand is greater than the one of the teeth.

  13. Rescue of odontogenesis in Dmp1-deficient mice by targeted re-expression of DMP1 reveals roles for DMP1 in early odontogenesis and dentin apposition in vivo.

    Science.gov (United States)

    Lu, Yongbo; Ye, Ling; Yu, Shibin; Zhang, Shubin; Xie, Yixia; McKee, Marc D; Li, Yan Chun; Kong, Juan; Eick, J David; Dallas, Sarah L; Feng, Jian Q

    2007-03-01

    Dentin matrix protein 1 (DMP1) is expressed in both pulp and odontoblast cells and deletion of the Dmp1 gene leads to defects in odontogenesis and mineralization. The goals of this study were to examine how DMP1 controls dentin mineralization and odontogenesis in vivo. Fluorochrome labeling of dentin in Dmp1-null mice showed a diffuse labeling pattern with a 3-fold reduction in dentin appositional rate compared to controls. Deletion of DMP1 was also associated with abnormalities in the dentinal tubule system and delayed formation of the third molar. Unlike the mineralization defect in Vitamin D receptor-null mice, the mineralization defect in Dmp1-null mice was not rescued by a high calcium and phosphate diet, suggesting a different effect of DMP1 on mineralization. Re-expression of Dmp1 in early and late odontoblasts under control of the Col1a1 promoter rescued the defects in mineralization as well as the defects in the dentinal tubules and third molar development. In contrast, re-expression of Dmp1 in mature odontoblasts, using the Dspp promoter, produced only a partial rescue of the mineralization defects. These data suggest that DMP1 is a key regulator of odontoblast differentiation, formation of the dentin tubular system and mineralization and its expression is required in both early and late odontoblasts for normal odontogenesis to proceed.

  14. Decellularized Human Dental Pulp as a Scaffold for Regenerative Endodontics.

    Science.gov (United States)

    Song, J S; Takimoto, K; Jeon, M; Vadakekalam, J; Ruparel, N B; Diogenes, A

    2017-06-01

    Teeth undergo postnatal organogenesis relatively late in life and only complete full maturation a few years after the crown first erupts in the oral cavity. At this stage, development can be arrested if the tooth organ is damaged by either trauma or caries. Regenerative endodontic procedures (REPs) are a treatment alternative to conventional root canal treatment for immature teeth. These procedures rely on the transfer of apically positioned stem cells, including stem cells of the apical papilla (SCAP), into the root canal system. Although clinical success has been reported for these procedures, the predictability of expected outcomes and the organization of the newly formed tissues are affected by the lack of an available suitable scaffold that mimics the complexity of the dental pulp extracellular matrix (ECM). In this study, we evaluated 3 methods of decellularization of human dental pulp to be used as a potential autograft scaffold. Tooth slices of human healthy extracted third molars were decellularized by 3 different methods. One of the methods generated the maximum observed decellularization with minimal impact on the ECM composition and organization. Furthermore, recellularization of the scaffold supported the proliferation of SCAP throughout the scaffold with differentiation into odontoblast-like cells near the dentinal walls. Thus, this study reports that human dental pulp from healthy extracted teeth can be successfully decellularized, and the resulting scaffold supports the proliferation and differentiation of SCAP. The future application of this form of an autograft in REPs can fulfill a yet unmet need for a suitable scaffold, potentially improving clinical outcomes and ultimately promoting the survival and function of teeth with otherwise poor prognosis.

  15. Tensile bond strength and SEM evaluation of caries-affected dentin using dentin adhesives.

    Science.gov (United States)

    Nakajima, M; Sano, H; Burrow, M F; Tagami, J; Yoshiyama, M; Ebisu, S; Ciucchi, B; Russell, C M; Pashley, D H

    1995-10-01

    Tensile bond strength measurements are commonly used for the evaluation of dentin adhesive systems. Most tests are performed using extracted non-carious human or bovine dentin. However, the adhesion of resins to caries-affected dentin is still unclear. The objectives of this study were to test the hypothesis that bonding to caries-affected dentin is inferior to bonding to normal dentin, and that the quality of the hybrid layer plays a major role in creating good adhesion. We used a micro-tensile bond strength test to compare test bond strengths made to either caries-affected dentin or normal dentin, using three commercial adhesive systems (All Bond 2, Scotchbond Multi-Purpose, and Clearfil Liner Bond II). For scanning electron microscopy, the polished interfaces between the adhesive bond and dentin were subjected to brief exposure to 10% phosphoric acid solution and 5% sodium hypochlorite, so that the quality of the hybrid layers could be observed. Bonding to normal dentin with either All Bond 2 (26.9 +/- 8.8 MPa) or Clearfil Liner Bond II (29.5 +/- 10.9 MPa) showed tensile bond strengths higher than those to caries-affected dentin (13.0 +/- 3.6 MPa and 14.0 +/- 4.3 MPa, respectively). The tensile bond strengths obtained with Scotchbond Multi-Purpose were similar in normal and caries-affected dentin (20.3 +/- 5.5 MPa and 18.5 +/- 4.0 MPa, respectively). The hybrid layers created by All Bond 2 in normal dentin and by Clearfil Liner Bond II in normal or caries-affected dentin showed phosphoric acid and sodium hypochlorite resistance, whereas the hybrid layers created by All Bond 2 in caries-affected dentin and those created by Scotchbond Multi-Purpose to normal and caries-affected dentin showed partial susceptibility to the acid and sodium hypochlorite treatment. The results indicate that the strength of adhesion to dentin depends upon both the adhesive system used and the type of dentin. Moreover, the quality of the hybrid layer may not always contribute

  16. ISR Intersection Vacuum Chamber

    CERN Multimedia

    1975-01-01

    This special vacuum chamber presenting a lateral opening at the beam crossing point is one of the many chambers specifically designed for a particular experiment. Here it is shown during assembly at the ISR mechanical worshop.

  17. Microbiome of Deep Dentinal Caries Lesions in Teeth with Symptomatic Irreversible Pulpitis.

    Directory of Open Access Journals (Sweden)

    Isabela N Rôças

    Full Text Available This study used a next-generation sequencing approach to identify the bacterial taxa occurring in the advanced front of caries biofilms associated with pulp exposure and irreversible pulpitis. Samples were taken from the deepest layer of dentinal caries lesions associated with pulp exposure in 10 teeth diagnosed with symptomatic irreversible pulpitis. DNA was extracted and the microbiome was characterized on the basis of the V4 hypervariable region of the 16S rRNA gene by using paired-end sequencing on Illumina MiSeq device. Bacterial taxa were mapped to 14 phyla and 101 genera composed by 706 different OTUs. Three phyla accounted for approximately 98% of the sequences: Firmicutes, Actinobacteria and Proteobacteria. These phyla were also the ones with most representatives at the species level. Firmicutes was the most abundant phylum in 9/10 samples. As for genera, Lactobacillus accounted for 42.3% of the sequences, followed by Olsenella (13.7%, Pseudoramibacter (10.7% and Streptococcus (5.5%. Half of the samples were heavily dominated by Lactobacillus, while in the other half lactobacilli were in very low abundance and the most dominant genera were Pseudoramibacter, Olsenella, Streptococcus, and Stenotrophomonas. High bacterial diversity occurred in deep dentinal caries lesions associated with symptomatic irreversible pulpitis. The microbiome could be classified according to the relative abundance of Lactobacillus. Except for Lactobacillus species, most of the highly prevalent and abundant bacterial taxa identified in this study have been commonly detected in infected root canals. The detected taxa can be regarded as candidate pathogens for irreversible pulpitis and possibly the pioneers in pulp invasion to initiate endodontic infection.

  18. Success Rate of MTA Pulpotomy on Vital Pulp of Primary Molars: A 3-Year Observational Study

    Science.gov (United States)

    Tyagi, Rishi

    2016-01-01

    Introduction Vital pulp therapy is a major contributor in the preservation of primary dentition after caries affliction. Introduction of mineral trioxide aggregate (MTA) has revolutionized such treatment. Aim The aim of our study was to evaluate and correlate the effects of MTA clinically and radiographically on pulpotomized primary molars till their exfoliation or extraction followed by histological evaluation. Study design This is an observational study. Materials and methods A total of 25 teeth were selected from 5- to 8-year-old children requiring pulp therapy on the basis of inclusion and exclusion criterion. The teeth were treated by conventional pulpotomy technique under aseptic conditions using MTA and were immediately restored with stainless steel crown. The teeth were assessed postoperatively till 36 months. The exfoliated or extracted teeth were examined histologically. Results The pulpotomized teeth were vital with no adverse clinical findings during the observation period. After 3 months, one tooth showed internal resorption, but the same was not observed after 12 months. Pulp canal obliteration was seen in three cases. At the end of the study, five teeth were exfoliated and one tooth was extracted for maintaining arch symmetry. The histological examination of extracted tooth revealed the presence of healthy pulp and the area of true calcification. Remaining exfoliated teeth presented dentin bridge formation. Statistics Frequencies and percentages were used for descriptive statistics. Fisher’s exact tests were used to see the difference between clinical and radiological findings. The probability value was fixed at 5% level of significance. Conclusion The response of pulp in primary teeth to MTA was favorable in all cases from clinical and radiographic perspective, and histological evaluation confirmed the observation. How to cite this article Godhi B, Tyagi R. Success Rate of MTA Pulpotomy on Vital Pulp of Primary Molars: A 3-Year Observational Study

  19. SEM evaluation of resin-carious dentin interfaces formed by two dentin adhesive systems

    Science.gov (United States)

    Hsu, Kuang-Wei; Marshall, Sally J.; Pinzon, Lilliam M.; Watanabe, Larry; Saiz, Eduardo; Marshall, Grayson W.

    2008-01-01

    Objectives We investigated the influence of dentin tubule direction and identifiable zone of carious dentin on the microstructure and the thickness of the hybrid-like layer (HL) formed by self-etch and etch-rinse adhesive systems. Methods An etch-rinse and a self-etching adhesive were bonded to dentin carious zones divided into groups with parallel or perpendicular orientation relative to the dentin tubules at the resin-carious dentin interface (N = 5/variable). Bonds were prepared to each of the four zones of carious dentin apparent after staining with Caries Detector: pink, light pink, transparent and apparently normal Six non-carious third molars were controls. The microstructure and thickness of the HL were determined by SEM.and compared using three-way ANOVA and Tukey's multiple comparisons (pcarious zone. PMID:18155289

  20. Biodentine induces immortalized murine pulp cell differentiation into odontoblast-like cells and stimulates biomineralization.

    Science.gov (United States)

    Zanini, Marjorie; Sautier, Jean Michel; Berdal, Ariane; Simon, Stéphane

    2012-09-01

    Biodentine (Septodont, Saint Maur des Faussés, France), a new tricalcium silicate-based cement, has recently been commercialized and advertised as a bioactive material. Its clinical application and physical properties have been widely described, but, so far, its bioactivity and biological effect on pulp cells have not been clearly shown. Thus, the aim of this study was to evaluate the biological effect of Biodentine on immortalized murine pulp cells (OD-21). OD-21 cells were cultured with or without Biodentine. Cell proliferation was determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) colorimetric assay after 2, 3, and 5 days of stimulation. The expression of several biomolecular markers was analyzed to screen differentiation pathways, both on a gene level with Real-time reverse transcription polymerase chain reaction and on a protein level by measuring alkaline phosphatase activity. Alizarin red staining was used to assess and quantify biomineralization. The expression patterns of several genes confirmed the differentiation of OD-21 cells into odontoblasts during the period of cell culture. Our results suggest that Biodentine is bioactive because it increased OD-21 cell proliferation and biomineralization in comparison with controls. Because of its bioactivity, Biodentine can be considered as a suitable material for clinical indications of dentin-pulp complex regeneration, such as direct pulp capping. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  1. Histological evaluation of pulp tissue from second primary molars correlated with clinical and radiographic caries findings

    Directory of Open Access Journals (Sweden)

    Vellore Kannan Gopinath

    2014-01-01

    Full Text Available Background: Managing dental caries in young children is demanding due to the elusions present on the right diagnostic criteria for treatment. The present study evaluated the histological status of pulp tissues extracted from primary second molar with caries involvement. Histological findings are correlated with clinical and radiographic assessment. Materials and Methods: Simple experimental study was conducted on upper or lower second primary molars with occlusal (22 teeth or proximal (22 teeth dental caries. Selected children were below 6 years of age. Percentage of caries involvement, residual dentin thickness (RDT, radiographic assessment of interradicular and periapical areas, clinical caries depth and signs and symptoms are the parameters considered for comparing with the histological findings. The specimens were grouped based on the nature of the inflammatory process as acute or chronic. The data were analyzed by Student t-test to compare histological types of inflammation with clinical parameters. P value < 0.05 was considered as significant. Results: Four cases revealed severe acute inflammation in coronal and relatively mild acute inflammation in radicular pulp. In the rest of the specimen coronal and radicular pulp had similar acute or chronic inflammatory changes. Histological evidence of pulpitis correlated with dental caries depth of ≥80%, RDT of ≤1 mm, radiographic rarefactions in the interradicular regions and symptoms of pain. Conclusion: Primary second molars with more than two-third caries involvement with symptoms of pain histologically showed inflammation of both coronal and radicular pulp tissues in all cases.

  2. Pulp therapy in primary teeth--profile of teaching in Brazilian dental schools.

    Science.gov (United States)

    Bergoli, Anieli Dossa; Primosch, Robert Eliot; de Araujo, Fernando Borba; Ardenghi, Thiago Machado; Casagrande, Luciano

    2010-01-01

    This study investigates the profile of teaching primary tooth pulp therapy practiced by Brazilian dental schools. A multiple-choice questionnaire was sent by e-mail to 191 dental schools in Brazil, addressed to the pediatric dentistry Chairperson. The two-part survey consisting of multiple-choice questions regarding specific materials and techniques on pulp therapies, moreover, hypothetical clinical scenarios were presented so that the respondents could guide the treatment approach. The questionnaires were returned by 46.5% of the dental schools. Ninety-five percent of surveyed schools teach IPT for the treatment of deep carious lesions in dentin and indicate the calcium hydroxide as capping material (59.3%). The direct pulp capping is taught by 68.7% of schools and calcium hydroxide (97%) was the capping material most indicated. Pulpotomy is taught in 98.7% of schools and formocresol (1:5 dilution) was the medicament of choice (50%). All schools taught pulpectomy and Iodoform paste was the filling material preferred (55%). The results showed a lack of consensus in certain modalities and techniques for primary tooth pulp therapy taught by Brazilian dental schools.

  3. Treatment of deep caries lesions in adults: randomized clinical trials comparing stepwise vs. direct complete excavation, and direct pulp capping vs. partial pulpotomy.

    Science.gov (United States)

    Bjørndal, Lars; Reit, Claes; Bruun, Gitte; Markvart, Merete; Kjaeldgaard, Marianne; Näsman, Peggy; Thordrup, Marianne; Dige, Irene; Nyvad, Bente; Fransson, Helena; Lager, Anders; Ericson, Dan; Petersson, Kerstin; Olsson, Jadranka; Santimano, Eva M; Wennström, Anette; Winkel, Per; Gluud, Christian

    2010-06-01

    Less invasive excavation methods have been suggested for deep caries lesions. We tested the effects of stepwise vs. direct complete excavation, 1 yr after the procedure had been carried out, in 314 adults (from six centres) who had received treatment of a tooth with deep caries. The teeth had caries lesions involving 75% or more of the dentin and were centrally randomized to stepwise or direct complete excavation. Stepwise excavation resulted in fewer pulp exposures compared with direct complete excavation [difference: 11.4%, 95% confidence interval (CI) (1.2; 21.3)]. At 1 yr of follow-up, there was a statistically significantly higher success rate with stepwise excavation, with success being defined as an unexposed pulp with sustained pulp vitality without apical radiolucency [difference: 11.7%, 95% CI (0.5; 22.5)]. In a subsequent nested trial, 58 patients with exposed pulps were randomized to direct capping or partial pulpotomy. We found no significant difference in pulp vitality without apical radiolucency between the two capping procedures after more than 1 yr [31.8% and 34.5%; difference: 2.7%, 95% CI (-22.7; 26.6)]. In conclusion, stepwise excavation decreases the risk of pulp exposure compared with direct complete excavation. In view of the poor prognosis of vital pulp treatment, a stepwise excavation approach for managing deep caries lesions is recommended.

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

    Science.gov (United States)

    Mollica, Fernanda Brandão; Rocha Gomes Torres, Carlos; Gonçalves, Sergio Eduardo de Paiva; Mancini, Maria Nadir Gasparoto

    2012-01-01

    There are several methods for identifying carious dentinal tissue aiming to avoid removal of healthy dentinal tissue. 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. 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. 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). 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.

  5. Optical Spectroscopy Study of Transparent Non-Carious Human Dentin and Dentin-Enamel Junction

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, G.W.; Marshall, S.J.; Gallagher, R.R.; Demos, S.

    1999-12-14

    Improving our knowledge of the morphology, composition and properties of the dentin, enamel, and the dentin-enamel junction (DEJ) is vital for the development of improved restorative materials and clinical placement techniques. Most studies of dental tissues have used light microscopy for characterization. In our investigation, the spectroscopic properties of normal and non-carious transparent human root dentin, and the dentin-enamel junction were investigated using emission imaging microscopy, and micro-spectroscopy. Experimental results reveal new information on the structural and biochemical characteristics of these dental tissues.

  6. Biochemical composition of carious dentin and different layers of sound dentin.

    Science.gov (United States)

    Magnus, Larissa; Maltz, Marisa; Bavaresco, Caren; Bastos, Lucelen F; Hashizume, Lina N

    2013-01-01

    The aim of this study was to evaluate the concentrations of calcium (Ca), inorganic phosphate (Pi) and fluoride (F) in carious dentin and in different layers of sound dentin. The samples examined were 52 permanent teeth (26 sound and 26 carious), which were subjected to two experiments to assess the mineral content of: 1) two layers (internal and external) of sound dentin and 2) sound and carious dentin. Ca and Pi were analyzed using a colorimetric method with arsenazo III (C22H18As2N4O14S2) and molybdate reagents, and F was analyzed using a specific electrode. A non-parametric test, the Mann-Whitney test, was used to verify differences between groups. Sound dentin showed a higher concentration of fluoride in the internal layer than in the external layer (P = 0.03), but no inter-layer differences in Ca or Pi concentration were evident. Lower concentrations of Ca, Pi and F were observed in carious dentin than in sound dentin (P carious dentin has lower concentrations of Ca, Pi and F than sound dentin.

  7. A new method to extract dental pulp DNA: application to universal detection of bacteria.

    Directory of Open Access Journals (Sweden)

    Lam Tran-Hung

    Full Text Available BACKGROUND: Dental pulp is used for PCR-based detection of DNA derived from host and bacteremic microorganims. Current protocols require odontology expertise for proper recovery of the dental pulp. Dental pulp specimen exposed to laboratory environment yields contaminants detected using universal 16S rDNA-based detection of bacteria. METHODOLOGY/PRINCIPAL FINDINGS: We developed a new protocol by encasing decontaminated tooth into sterile resin, extracting DNA into the dental pulp chamber itself and decontaminating PCR reagents by filtration and double restriction enzyme digestion. Application to 16S rDNA-based detection of bacteria in 144 teeth collected in 86 healthy people yielded a unique sequence in only 14 teeth (9.7% from 12 individuals (14%. Each individual yielded a unique 16S rDNA sequence in 1-2 teeth per individual. Negative controls remained negative. Bacterial identifications were all confirmed by amplification and sequencing of specific rpoB sequence. CONCLUSIONS/SIGNIFICANCE: The new protocol prevented laboratory contamination of the dental pulp. It allowed the detection of bacteria responsible for dental pulp colonization from blood and periodontal tissue. Only 10% such samples contained 16S rDNA. It provides a new tool for the retrospective diagnostic of bacteremia by allowing the universal detection of bacterial DNA in animal and human, contemporary or ancient tooth. It could be further applied to identification of host DNA in forensic medicine and anthropology.

  8. Effect of adhesive system and application strategy on reduction of dentin permeability

    Directory of Open Access Journals (Sweden)

    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.

  9. Observations on pulpal response to carbon dioxide laser drilling of dentine in healthy human third molars.

    Science.gov (United States)

    Nair, P N R; Baltensperger, M; Luder, H U; Eyrich, G K H

    2005-01-01

    Preservation of pulpal health is the primary prerequisite for successful application of laser systems in the hard tissue management of vital teeth. The purpose of this study was to investigate the short and long-term pulpal effects to cavity preparations in healthy human teeth using carbon dioxide (CO2) laser. A total of seven, healthy, third molars that were scheduled to be removed due to space problems were used. After the laser drilling, the occlusal cavities were closed temporarily, and the teeth were extracted 7 days (n=5) and 3 months (n=2) after the operation. The specimens were fixed, decalcified, subdivided and processed for light and transmission electron microscopy. Seven days postoperatively all the five teeth that had been irradiated with the CO2 laser did not reveal any pathological changes in the pulpo-dentine complex. Three months postoperatively the two teeth that were prepared with the laser showed subtle but distinct apposition of tertiary dentine that was lined with intact odontoblasts. One of the specimens at 3 months revealed the presence of a mild, but very circumscribed, pulpal infiltration of chronic inflammatory cells subjacent to the cavity preparation. The latter is unlikely to be due to a direct effect of the laser irradiation but a possible consequence of microleakage of oral antigens and/or other tissue-irritating molecules through the temporary restoration and the remaining dentine thickness (RDT). Although these preliminary histological results suggest that the CO2 laser under investigation induced only minimal response of the dentine-pulp complex when used as a hard-tissue drilling tool, with specific energy settings, pulse duration within thermal relaxation time and emitting radiations at 9.6 microm of wavelength, larger clinical trials involving various types of teeth are necessary to reach definite conclusions for large-scale clinical application of the laser device.

  10. Pulping of the giant leucaena wood. I. Pulping by the kraft process

    Energy Technology Data Exchange (ETDEWEB)

    Usami, K.; Ogino, T.; Takano, I.; Shimada, K.; Nishida, A.

    1980-01-01

    Cooking of Leucaena latisiliqua with kraft liquor (30% sulfidity as Na/sub 2/O) at 160 degrees gave 59.1% pulp with Kappa number 59.0 and Hunter brightness 19.9. The strength properties of pulp were comparable to those of beech pulp. It was confirmed that the extractives remaining in the bleached pulp adversely affect the color reversion.

  11. SYNERGISTIC EFFECTS BETWEEN BIRCH CHEMICAL MECHANICAL PULPS AND ASPEN BLEACHED KRAFT PULP

    Institute of Scientific and Technical Information of China (English)

    Eric C. Xu; Yajun Zhou

    2004-01-01

    In this investigation, two different grades of birch chemical mechanical (P-RC APMP) pulps and aspen market bleached kraft pulp were compared by low consistency refining of the pulps separately and in different combinations. In addition, the separately refined pulps were also combined to compare with the pulps from the co-refined pulp blend. The results showed that in both cases there were synergistic effects between the two types of pulps: adding the birch P-RC APMP pulp to the aspen kraft pulp improved pulp properties, and the resultant pulp blends had a higher fiber bonding strength (tensile and tensile energy absorption) than the sum of weighted contributions from the individual components. Understanding this synergistic effect between chemical mechanical (P-RC APMP) and kraft pulps can help to improve their applications and performances in various papermaking processes.The results also showed that introducing, at least up to certain percentage of, the birch P-RC APMP pulp into the aspen bleached kraft pulp not only improves optical and bulk properties, but also maintains or improves tensile strength, even though the P-RC APMP pulp used has lower tensile than the kraft pulp.

  12. SYNERGISTIC EFFECTS BETWEEN BIRCH CHEMICAL MECHANICAL PULPS AND ASPEN BLEACHED KRAFT PULP

    Institute of Scientific and Technical Information of China (English)

    EricC.Xu; YajunZhou

    2004-01-01

    In this investigation, two different grades of birch chemical mechanical (P-RC APMP) pulps and aspen market bleached kraft pulp were compared by low consistency refining of the pulps separately and in different combinations. In addition, the separately refined pulps were also combined to compare with the pulps from the co-refined pulp blend. The results showed that in both cases there were synergistic effects between the two types of pulps: adding the birch P-RC APMP pulp to the aspen kraft pulp improved pulp properties, and the resultant pulp blends had a higher fiber bonding strength (tensile and tensile energy absorption) than the sum of weighted contributions from the individual components. Understanding this synergistic effect between chemical mechanical (P-RC APMP) and kraft pulps can help to improve their applications and performances in various papermaking processes. The results also showed that introducing, at least up to certain percentage of, the birch P-RC APMP pulp into the aspen bleached kraft pulp not only improves optical and bulk properties, but also maintains or improves tensile strength, even though the P-RC APMP pulp used has lower tensile than the kraft pulp.

  13. Dissolving pulp from jute stick.

    Science.gov (United States)

    Matin, Mhafuza; Rahaman, M Mostafizur; Nayeem, Jannatun; Sarkar, Mamon; Jahan, M Sarwar

    2015-01-22

    Jute stick is woody portion of jute plant, which remain as leftover after extracting bast fibre. Presently, it is being used for fencing in the rural area. In this investigation, biorefinery concept was initiated in producing dissolving pulp from jute stick by pre-hydrolysis kraft process. At 170°C for 1h of pre-hydrolysis, 70% of hemicelluloses was dissolved with negligible loss of α-cellulose. At this condition, 75% of dissolved sugars in the pre-hydrolysis liquor were in the oligomeric form. The pre-hydrolysed jute stick was subsequently pulped by kraft process with the variation of active alkali. The pulp yield was 36.2% with kappa number 18.5 at the conditions of 16% active alkali for 2h of cooking at 170°C. Final pulp was produced with 92% α-cellulose and 89% brightness after D0EpD1EpD1 bleaching. The produced dissolving pulp can be used in rayon production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Isolated dentinogenesis imperfecta and dentin dysplasia: revision of the classification.

    Science.gov (United States)

    de La Dure-Molla, Muriel; Philippe Fournier, Benjamin; Berdal, Ariane

    2015-04-01

    Dentinogenesis imperfecta is an autosomal dominant disease characterized by severe hypomineralization of dentin and altered dentin structure. Dentin extra cellular matrix is composed of 90% of collagen type I and 10% of non-collagenous proteins among which dentin sialoprotein (DSP), dentin glycoprotein (DGP) and dentin phosphoprotein (DPP) are crucial in dentinogenesis. These proteins are encoded by a single gene: dentin sialophosphoprotein (DSPP) and undergo several post-translational modifications such as glycosylation and phosphorylation to contribute and to control mineralization. Human mutations of this DSPP gene are responsible for three isolated dentinal diseases classified by Shield in 1973: type II and III dentinogenesis imperfecta and type II dentin dysplasia. Shield classification was based on clinical phenotypes observed in patient. Genetics results show now that these three diseases are a severity variation of the same pathology. So this review aims to revise and to propose a new classification of the isolated forms of DI to simplify diagnosis for practitioners.

  15. Leeuwenhoek and the structure of dentine.

    Science.gov (United States)

    O'Sullivan, R; Flannelly, M

    1990-01-01

    This short paper includes extracts from the original translations of Leeuwenhoek's descriptions of the histology of teeth, investigates his findings and demonstrates that in addition to describing dentinal tubules, he may have identified the presence of calcospherites within that tissue.

  16. Effect of two contemporary root canal sealers on root canal dentin microhardness

    Science.gov (United States)

    2017-01-01

    Background Successful root canal treatment depends on proper cleaning, disinfecting and shaping of the root canal space. Pulpless teeth have lower dentin microhardness value compared to that of vital teeth. A material which can cause change in dentin composition may affect the microhardness. Thus the aim of this study was to evaluate and compare the effect of two root canal sealers on dentin microhardness. Material and Methods Forty two single rooted teeth were selected and divided into 3 equal groups; Apexit, iRootSP and control groups (n=14) Each group was then divided into 2 subgroups according to the post evaluation period; 1 week and 2 months (n=7). Root canal procedure was done in the experimental groups and obturation was made using either; Apexit, iRootSP or left unprepared and unobturated in the control group. Roots were sectioned transversely into cervical, middle and apical segments. The three sections of each root were mounted in a plastic chuck with acrylic resin. The coronal dentin surfaces of the root segments werepolished. Microhardness of each section was measured at 500 µm and 1000 µm from the canal lumen. Results Four way-ANOVA revealed that different tested sealer materials, canal third, measuring distance from the pulp and time as independent variables had statistically non significant effect on mean microhardness values (VHN) at p≤0.001. Among iRootSP groups there was a statistically significant difference between iRoot SP at coronal root portion (87.79±17.83) and iRoot SP at apical root portion (76.26±9.33) groups where (p=0.01). IRoot SP at coronal canal third had higher statistically significant mean microhardness value (87.79±17.83) compared to Apexit at coronal third (73.61±13.47) where (p=0.01). Conclusions Root canal sealers do not affect dentin microhardness. Key words:Root canal, dentin, sealers, microhardness, bioceramic. PMID:28149466

  17. Age-at-death estimation by pulp/tooth area ratio in canines: study of a 20th-century Mexican sample of prisoners to test Cameriere's method.

    Science.gov (United States)

    De Luca, Stefano; Bautista, Josefina; Alemán, Inmaculada; Cameriere, Roberto

    2011-09-01

    Accurate age estimation has always been a problem for forensic scientists, and apposition of secondary dentine is often used as an indicator of age. Cameriere et al. studied the pulp/tooth area ratio by peri-apical X-ray images of the canines, to observe the apposition of secondary dentine. The present study examines the application of this technique in a Mexican identified sample coming from the Department of Physical Anthropology of the INAH, at Mexico City. The main aim of this work is to test the reliability of this method in a skeletal sample of a specific population, different from the samples used for its development. The obtained regression model explained 96.2% of total variance (R(2) = 0.962) with a standard error of estimate of 1.909 and a standard deviation of 1.947. These results demonstrate great reliability and that the age/secondary dentine relationship is not variable in this specific population.

  18. Study on the micropermeability of resin-dentin bonding interfaces with ethanol-wet bonding technique%乙醇润湿对牙本质粘接界面渗透性的影响

    Institute of Scientific and Technical Information of China (English)

    陈东平; 裴丹丹; 王亚珂; 黄翠; 阿达莱提·麻合苏提; 刘思颖

    2011-01-01

    min ( group 3 ),3 min ( group 4 ) or with a series of increasing ethanol concentrations before application of hydrophobic adhesive ( group 5 ).All the bonding procedures were done under simulated pulp pressure.After 24 hours,micro-tensile bond strength test were performed on the specimens.Bonding interfaces were observed under laser scanning confocal microscope (LSCM) after the pulp chamber were filled with a water-soluble fluoroprobe rhodamine B for 3 hours.Results Compared with the control group[(38.14 ± 4.97 ) MPa],bond strengths in group 1 [(21.02 ± 7.23 ) MPa]and group 2 [( 29.64 ± 3.81 ) MPa]were statistically lower ( P > 0.05 ),while bond strngth in group 3 [( 38.40 ± 5.03 ) MPa],group 4 [( 37.26 ± 4.68 ) MPa]and group 5[(40.12 ±5.95) MPa]were similar to the control group (P<0.05).The images taken by LSCM showed that with extension of ethanol-wet time,the deposition of fluorescent dye in hybrid layer and along the dentinal tubules decreased gradually.Especially in group 5,only spare fluorescent dye deposition could be detected in the hybrid layer.Conclusions Dentin saturated with ethanol for more than 2 min before bonding hydrophobic adhesive to dentin could provide favorable bond strength and decreased the micropermeability of bonding interfaces under simulated pulp pressure.

  19. FHL2 mediates tooth development and human dental pulp cell differentiation into odontoblasts, partially by interacting with Runx2.

    Science.gov (United States)

    Du, Jianxin; Wang, Qiang; Yang, Pishan; Wang, Xiaoying

    2016-04-01

    The differentiation of mesenchymal cells in tooth germ and dental pulp cells into odontoblasts is crucial for dentin formation, and the transcription factor runt-related transcription factor (Runx2) is necessary for odontoblast differentiation. Our previous study demonstrated that four and a half LIM domains 2 (FHL2) may play an important role in tooth development and human dental pulp cell differentiation. This study aimed to determine whether FHL2 mediated the mesenchymal cells in tooth development and human dental pulp cell differentiation into odontoblasts by interacting with Runx2. The expression patterns of FHL2 and Runx2 were examined at the early stages of mouse molar development using double immunofluorescence staining. Western blot analysis and co-immunoprecipitation (Co-IP) were conducted for the preliminary study of the relationship between FHL2 and Runx2 in human dental pulp cell differentiation into odontoblasts. Results of double immunofluorescence staining showed that FHL2 and Runx2 exhibited similar expression patterns at the early stages of tooth development. Western blot analysis indicated that the expression patterns of FHL2 and Runx2 were synchronized on day 7 of induction, whereas those on day 14 differed. Co-IP analysis revealed positive bands of protein complexes, revealing the interaction of FHL2 and Runx2 on days 0, 7 and 14 of induction. Our data suggested that FHL2 might interact with Runx2 to mediate mesenchymal cell differentiation at the early stages of tooth development and human dental pulp cell differentiation.

  20. APPLICATION OF SURFACTANTS AS PULPING ADDITIVES IN SODA PULPING OF BAGASSE

    OpenAIRE

    2009-01-01

    The effects of several non-ionic commercial surfactants and their dosage on soda pulping and ECF bleaching of soda and soda-surfactant pulps of bagasse were investigated. The properties of bleachable pulps obtained with conventional soda and with soda-surfactants were studied and compared. The results showed application of surfactants during the soda pulping of bagasse decreased kappa number and improved the yield and brightness of resulting pulp. Using the surfactants reduced alkali consumpt...

  1. Current status of dentin adhesive systems.

    Science.gov (United States)

    Leinfelder, K F

    1998-12-01

    Undoubtedly, dentin bonding agents have undergone a major evolution during the last several years. The shear bond strength of composite resin to the surface of dentin is actually greater than the inherent strength of the dentin itself under well-controlled conditions. No longer must the clinician depend only upon the bonding to enamel as the sole bonding mechanism. Bonding to both types of dental structure permits even better reinforcement of the tooth itself. Perhaps even more important than the high level of bonding exhibited by the current dentin adhesives is their ability to seal the dentin. So effective is this sealing capability that it is now possible to protect the pulpal tissue from microbial invasion through the dentinal tubules. Further, by enclosing the odontoblastic processes and preventing fluid flow, the potential for postoperative sensitivity is diminished considerably. In fact, so evolutionary is the concept of bonding that the procedures associated with the restoration of teeth has changed dramatically. Undoubtedly, far greater improvements can be anticipated in the future.

  2. Remineralization of caries lesions extending into dentin.

    Science.gov (United States)

    ten Cate, J M

    2001-05-01

    Remineralization is one aspect of the overall process of tooth decay. However, it is primarily studied in shallow lesions. The aim of this study was to explore whether caries lesions in enamel and extending into the dentin can be remineralized. A single-section model was developed for the longitudinal and non-destructive monitoring of changes in enamel and dentin. Lesions at least 200 microm into dentin were formed in undersaturated acetate buffers. Next, the lesions were divided into groups (three treatment and one control) and remineralized. The treatments were: weekly immersion in 1,000 ppm fluoride, single treatment with methanehydroxybisphosphonate, and a constant level of 1 ppm fluoride. De- and remineralization was assessed by transverse microradiography. Remineralization was observed in enamel, but also in dentin, indicating that, deep into dentin, the pores become supersaturated to apatite formation. Treatments affected remineralization only in the outer part of enamel. Both findings are explained by a relatively fast diffusion of mineral ions, with precipitation being rate-limiting. The results suggest that dentin remineralization, underneath enamel, can be achieved and could possibly be used in clinical treatment strategies.

  3. A clinical perspective on dentin adhesives.

    Science.gov (United States)

    Eichmiller, F C

    1993-01-01

    The newer generation of dentin adhesives has changed the practice of restorative dentistry. Two features common to most of the bonding restorative materials are the ability to alter, through the use of acidic etching agents, the surface of the dentin and the ability to completely wet and re-infiltrate the altered dentin surface with a hydrophilic polymerizable monomer. The acidic etchants remove or break up the smear layer, partially demineralize and/or alter the mineral in the first few microns of the dentin surface, and expose the collagen fibril network. The hydrophilic adhesive monomers that contain both acidic and methacrylate groups on the same molecule are bifunctional in nature. These monomers are able to infiltrate the demineralized dentin due to their hydrophilic nature and polymerize to encapsulate the exposed collagen fibers. Available products can be divided into two broad categories: systems that contain a low concentration of adhesive monomer diluted in a volatile solvent and systems that use adhesive resins of moderate to high viscosity. Knowledge of the features and properties of dentin adhesives provides the needed rationale for the protocol of application and the proper choice of materials in restorative dentistry.

  4. Permeability of normal versus carious dentin.

    Science.gov (United States)

    Pashley, E L; Talman, R; Horner, J A; Pashley, D H

    1991-10-01

    Although a number of reports have been published demonstrating that carious dentin is less permeable than normal dentin, these reports have been qualitative rather than quantitative. The purpose of this in vitro study was to apply a quantitative technique to the study of the permeability of carious human teeth before and after excavation, before and after removal of the smear layer and before and after preparation of a control cavity of similar size and depth in normal dentin subjected to the same measurements, for comparative purposes. Dentin permeability was measured as a hydraulic conductance. The permeability values measured at each step in the protocol were expressed as a percent of the maximum permeability of both cavities, permitting each tooth the serve as its own control. Carious lesions exhibited a slight degree of permeability (2.3 +/- 0.6% of controls) which remained unchanged after excavation of the lesions. Removal of the smear layer in the excavated carious lesions increased the permeability significantly to 6.9 +/- 3.2%. Preparation of a control cavity of the same area and depth increased the permeability slightly. Removal of its smear layer increased the permeability of the dentin 91%. These results confirm previous qualitative studies that carious dentin, even after excavation and removal of the smear layer has a very low permeability.

  5. Enzymatic hydrolysis of potato pulp

    Directory of Open Access Journals (Sweden)

    Mariusz Lesiecki

    2012-03-01

    Full Text Available Background. Potato pulp constitutes a complicated system of four types of polysaccharides: cellulose, hemicellulose, pectin and starch. Its composition makes it a potential and attractive raw material for the production of the second generation bioethanol. The aim of this research project was to assess the usefulness of commercial enzymatic preparations for the hydrolysis of potato pulp and to evaluate the effectiveness of hydrolysates obtained in this way as raw materials for ethanol fermentation. Material  and methods. Sterilised potato pulp was subjected to hydrolysis with commercial enzymatic preparations. The effectiveness of the preparations declared as active towards only one fraction of potato pulp (separate amylase, pectinase and cellulase activity and mixtures of these preparations was analysed. The monomers content in hydrolysates was determined using HPLC method. Results.  The application of amylolytic enzymes for potato pulp hydrolysis resulted in the release of only 18% of raw material with glucose as the dominant (77% constituent of the formed product. In addition, 16% galactose was also determined in it. The hydrolysis of the cellulose fraction yielded up to 35% raw material and the main constituents of the obtained hydrolysate were glucose (46% and arabinose (40%. Simultaneous application of amylolytic, cellulolytic and pectinolytic enzymes turned out to be the most effective way of carrying out the process as its efficiency in this case reached 90%. The obtained hydrolysate contained 63% glucose, 25% arabinose and 12% other simple substances. Conclusion. The application of commercial enzymatic preparations made it possible to perform potato pulp hydrolysis with 90% effectiveness. This was achieved by the application of a complex of amylolytic, cellulolytic and pectinolytic enzymes and the hydrolysate obtained in this way contained, primarily, glucose making it a viable substrate for ethanol fermentation.

  6. Pulp response to high fluoride releasing glass ionomer, silver diamine fluoride, and calcium hydroxide used for indirect pulp treatment: An in-vivo comparative study

    Directory of Open Access Journals (Sweden)

    Atish Korwar

    2015-01-01

    Full Text Available Aims and Objectives: The study aims at determining pulp response of two high fluoride releasing materials silver diamine fluoride (SDF and Type VII glass ionomer cement (GIC when used as indirect pulp treatment (IPT materials. Materials and Methods: Deep Class V cavities were made on four first premolars indicated for extraction for orthodontic reasons. SDF, Type VII GIC, and calcium hydroxide base are given in three premolars, and one is kept control. Premolars were extracted 6 weeks after the procedure and subjected to histopathological examination to determine the pulp response. The results were analyzed using Chi-square test. Results: No inflammatory changes were observed in any of the groups. Significantly more number of specimens in SDF and Type VII GIC groups showed tertiary dentin deposition (TDD when compared to control group. No significant difference was seen in TDD when intergroup comparison was made. Odontoblasts were seen as short cuboidal cells with dense basophilic nucleus in SDF and Type VII GIC group. Conclusion: The study demonstrated TDD inducing ability of SDF and Type VII GIC and also established the biocompatibility when used as IPT materials.

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

    Directory of Open Access Journals (Sweden)

    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

  8. Comparative pulping of sunflower stalks

    Directory of Open Access Journals (Sweden)

    Valerii Barbash

    2016-03-01

    Full Text Available The procedure of holocellulose content determination in non-wood plant raw materials was developed. The strength properties of pulp obtained from sunflower stalks by neutral-sulphite, soda, alkaline sulphite-anthraquinone-ethanol and peracetic methods of delignification were studied. Methodology of comparison of plant materials delignification methods using new lignin-carbohydrate diagram was proposed. It was shown, that the alkaline sulphite-anthraquinone-ethanol method of pulping is characterized by the highest delignification degree and is the most efficient among the studied methods

  9. REINFORCEMENT POTENTIAL OF BLEACHED SAWDUST KRAFT PULP IN DIFFERENT MECHANICAL PULP FURNISHES

    Directory of Open Access Journals (Sweden)

    Risto I. Korpinen

    2009-11-01

    Full Text Available Bleached unrefined and refined sawdust kraft pulps were added to bleached Norway spruce thermomechanical (TMP and pressurised groundwood (PWG pulps in different proportions. Handsheets were prepared and tested for physical properties. In addition, economic calculations were done to estimate the production costs of different bleached pulps in Finland. It was found that the addition of unrefined and refined sawdust kraft pulp improved drainability of the mechanical pulps. Tear strength of PGW furnishes was increased when either unrefined or refined sawdust pulp was added. Tear strength of TMP furnishes was not influenced when different sawdust kraft pulps were added. Up to 30 % of unrefined sawdust kraft pulp could be added and no significant negative effect was observed in TMP and PGW furnishes. On the other hand, when refined sawdust kraft pulp was added into the mechanical pulp furnishes, a clear improvement in the tensile strength was observed. According to the economic calculation the production cost of bleached sawdust kraft pulp is almost as low as the production cost of bleached mechanical pulp. We suggest that economically viable sawdust kraft pulp can be used as a substituent for expensive long fibre reinforcement kraft pulp in the production of mechanical pulp based papers.

  10. Bioactive injectable aggregates with nanofibrous microspheres and human dental pulp stem cells: A translational strategy in dental endodontics.

    Science.gov (United States)

    Garzón, I; Martin-Piedra, M A; Carriel, V; Alaminos, M; Liu, X; D'Souza, R N

    2017-01-12

    Regeneration of the pulp-dentin complex with stem cells is a potential alternative to conventional root canal treatments. Human dental pulp stem cells (hDPSCs) have been extensively studied because of their ability to proliferate and differentiate into mineralized dental and non-dental tissues. Here we combined hDPSCs with two types of injectable poly-l-lactic acid (PLLA) microsphere with a nanofibrous or smooth surface to form bioactive injectable aggregates, and examined their ability to promote pulp regeneration in the root canal in an in vivo model. We investigated the biocompatibility, biosafety and odontogenic potential of fibrous (F-BIM) and smooth bioactive injectable microspheres (S-BIM) in vitro and in vivo. Our results demonstrated that PLLA microspheres and hDPSCs were able to form bioactive injectable aggregates that promoted dentin regeneration in both in vitro and in vivo models. Our results suggest that F-BIM and S-BIM may induce dentinogenesis upon in vivo grafting, and propose that the potential usefulness of the microsphere-hDPSC aggregates described here should be evaluated in clinical settings. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  11. The role of host-derived dentinal matrix metalloproteinases in reducing dentin bonding of resin adhesives.

    Science.gov (United States)

    Zhang, Shan-chuan; Kern, Matthias

    2009-12-01

    Dentin matrix metalloproteinases (MMPs) are a family of host-derived proteolytic enzymes trapped within mineralized dentin matrix, which have the ability to hydrolyze the organic matrix of demineralized dentin. After bonding with resins to dentin there are usually some exposed collagen fibrils at the bottom of the hybrid layer owing to imperfect resin impregnation of the demineralized dentin matrix. Exposed collagen fibrils might be affected by MMPs inducing hydrolytic degradation, which might result in reduced bond strength. Most MMPs are synthesized and released from odontoblasts in the form of proenzymes, requiring activation to degrade extracellular matrix components. Unfortunately, they can be activated by modem self-etch and etch-and-rinse adhesives. The aim of this review is to summarize the current knowledge of the role of dentinal host-derived MMPs in dentin matrix degradation. We also discuss various available MMP inhibitors, especially chlorhexidine, and suggest that they could provide a potential pathway for inhibiting collagen degradation in bonding interfaces thereby increasing dentin bonding durability.

  12. EFFECTS OF XYLAN IN EUCALYPTUS PULP PRODUCTION

    Directory of Open Access Journals (Sweden)

    Bianca Moreira Barbosa

    2016-06-01

    Full Text Available The search for a better use of wood in the pulp industry has fuelled interest in a more rational use of its components, particularly xylans. The impact of xylans removal and of xylans redeposition on pulp properties for tissue and P&W paper grades are discussed in this paper. Kraft pulp (15.6% xylans treatment with 10-70 g.L-1 NaOH resulted in pulps of 14.5-5.9% xylans. The treatments decreased pulp lignin and HexA contents and caused significant positive impact on subsequent oxygen delignification and ECF bleaching. Xylan removal decreased pulp beatability, water retention value and tensile index but increased drainability, water absorption capacity, capillarity Klemm and bulk. Overall, xylan depleted pulps showed almost ideal properties for tissue paper grade pulps. In a second step of the research, xylans extracted from unbleached (BXL and bleached eucalyptus pulps (WXL by cold caustic extraction (CCE were added to a commercial brown pulp in the oxygen delignification (O-stage and further bleached. Xylans deposition occurred at variable degree (up to 7% on pulp weight depending upon the O-stage reaction pH. Pulp bleachability was not impaired by WXL xylan deposition but slightly negatively affected by BXL xylans. Pulp beatability was improved by xylan deposition. The deposited xylans were quite stable across bleaching and beating, with the WXL xylans being more stable than the BXL ones. At low energy consumption, the deposited xylans improved pulp physical and mechanical properties. Xylans extraction by CCE with subsequent deposition onto pulp in the O-stage proved attractive for manufacturing high xylan P&W paper grades.

  13. Endodoncia preventiva: Protección pulpar mediante la técnica de eliminación de la caries en etapas (stepwise excavation Preventive endodontics: pulp protection using stepwise caries removal procedure

    Directory of Open Access Journals (Sweden)

    L. Castellanos-Cosano

    2011-10-01

    Full Text Available El tratamiento de la caries dentinaria profunda en dientes permanentes se ha venido realizando, generalmente, mediante la remoción completa y en una sola sesión de la dentina cariada, incluyendo la dentina blanda desmineralizada, sin tener en cuenta el potencial regenerador de la pulpa dental. Una complicación frecuentemente ligada a esta actitud es la exposición pulpar intraoperatoria que, en muchos casos, termina en tratamiento de conductos. Varios estudios han demostrado que la eliminación de la caries dentinaria profunda por etapas, en dos visitas con varios meses de diferencia, protege a la pulpa, disminuyendo la frecuencia de exposiciones pulpares, a la vez que permite la formación de dentina terciaria, con la consiguiente disminución del porcentaje de casos que requieren tratamiento endodóncico. En este artículo se analiza el estado del conocimiento y la evidencia científica sobre este tema.The treatment of deep dentine carious lesions in permanent teeth has included, generally, complete removal of affected dentin in a single session, including soft demineralized dentin, regardless of the regenerative potential of dental pulp. One complication often linked to this attitude is the pulp exposure, in many cases ending in root canal treatment. Several studies have shown that the elimination of deep dentine caries in stages, in two visits to several months apart, protects the pulp, reducing the frequency of pulp exposures, while allowing the development of tertiary dentin, with the consequent decrease in the percentage of cases requiring endodontic treatment. This article discusses the state of knowledge and scientific evidence on this topic.

  14. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  15. Prototype multiwire proportional chamber

    CERN Multimedia

    1975-01-01

    Chambers of this type were initially developed within the Alpha project (finally not approved). They were designed such to minimize the radiation length with a view to a mass spectrometer of high resolution meant to replace the Omega detector. The chambers were clearly forerunners for the (drift) chambers later built for R606 with the novel technique of crimping the wires. See also photo 7510039X.

  16. Electromagnetic reverberation chambers

    CERN Document Server

    Besnier, Philippe

    2013-01-01

    Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

  17. 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.

  18. EFFECT OF DENTIN TUBULES TO THE MECHANICAL PROPERTIES OF DENTIN.PART II:EXPERIMENTAL STUDY

    Institute of Scientific and Technical Information of China (English)

    Huo Bo; Zheng Quanshui; Zhang Qing; Wang Jiade

    2000-01-01

    To verify the theoretical models of varying transversely isotropic stress-strain relations of dentin established in the preceding work(Part I),we perform a set of experiments.Because of the very fine tooth size,it usually seems to be difficult to directly measure the inhomogeneons and anisotropic parameters of dentin.In this paper,by the digital speckle correlation method,tensile experiments are made on the small dentin samples either parallel or perpendicular to the dentin tubules.With the theoretically predicted elastic stress-strain relations,an optimization method is proposed to fit the strain curve adapted to the experimental data.The results show that the theoretical elastic stress-strain relations coincides very well with the experimental observations.The determined Young's modulus and Poisson's ratio of dentin matrix are 29.5GPa and 0.44,respectively,in the optimization sense.

  19. Antibacterial Effects of Antimicrobials Used in Regenerative Endodontics against Biofilm Bacteria Obtained from Mature and Immature Teeth with Necrotic Pulps.

    Science.gov (United States)

    Jacobs, Jordon C; Troxel, Alex; Ehrlich, Ygal; Spolnik, Kenneth; Bringas, Josef S; Gregory, Richard L; Yassen, Ghaeth H

    2017-04-01

    We investigated the direct and residual antibacterial effects of intracanal antimicrobials against bacterial biofilms obtained from infected mature and immature teeth with necrotic pulps. Sterile dentin slabs (n = 100) were inoculated with bacterial biofilms obtained from root canals of an immature or a mature tooth with pulpal necrosis and incubated anaerobically for 3 weeks (n = 50 per biofilm). Dentin infected with each type of biofilm received 1 week of treatment with 1 or 5 mg/mL double antibiotic paste (DAP) in methylcellulose hydrogels, calcium hydroxide, or placebo paste or received no treatment (n = 10). The pastes were removed, and biofilm disruption assays were performed. Additional dentin slabs (n = 100) were pretreated with the same treatments (n = 20). The pastes were rinsed off, and the samples were immersed in phosphate-buffered saline for 1 week. Thereafter, samples from the treatment groups were infected with bacterial biofilm from both clinical sources mentioned earlier (n = 10 per biofilm) and incubated anaerobically for 3 weeks before conducting biofilm disruption assays. Uninfected dentin slabs were used for both antibacterial experiments as negative control groups (n = 20). All antimicrobials showed significant direct antibacterial effects regardless of the biofilm source. Dentin pretreated with 5 mg/mL DAP provided significantly higher residual antibacterial effects in comparison with all other groups regardless of the source of biofilm. Dentin pretreated with calcium hydroxide did not show any residual antibacterial effects. Tested antimicrobials showed significant direct antibacterial effects. Only 5 mg/mL DAP exhibited significant residual antibacterial effects against bacterial biofilms from an infected root canal of an immature tooth. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  20. Evaluation of the Morphological Characteristics of Laser-Irradiated Dentin

    Science.gov (United States)

    Lilaj, Bledar; Franz, Alexander; Degendorfer, Daniela; Moritz, Andreas

    2015-01-01

    Abstract Objective: The aim of this study was to investigate the effect of different energy settings of Er:YAG laser irradiation on dentin surface morphology with respect to the number of opened dentinal tubules. Background data: An ideally prepared dentin surface with opened dentinal tubules is a prerequisite for adhesive fixation. No study, however, has yet compared the numbers of opened dentinal tubules with regard to statistical differences. Methods: Conventional preparations using a bur with or without additional acid etching acted as control groups. Dentin specimens were prepared from human third molars and randomly divided into eight groups according to the energy settings of the laser (1, 1.5, 4, 6, 7.5, and 8 W) and two controls (bur and bur plus acid etching). After surface preparation, dentin surfaces were analyzed with a scanning electron microscope, and the number of opened dentinal tubules in a defined area was counted. Results: The control groups showed smooth surfaces with (bur plus acid etching) and without opened dentinal tubules (bur), whereas all laser-irradiated surfaces showed rough surfaces. Using the energy setting of 4 W resulted in significantly more opened dentinal tubules than the conventional preparation technique using the bur with additional acid etching. In contrast, the energy setting of 8 W showed significantly fewer opened dentinal tubules, and also exhibited signs of thermal damage. Conclusions: The Er:YAG laser with an energy setting of 4 W generates a dentin surface with opened dentinal tubules, a prerequisite for adhesive fixation. PMID:26389986

  1. The peritubular reinforcement effect of porous dentine microstructure.

    Science.gov (United States)

    Wang, Rong; Niu, Lin; Li, Qun; Liu, Qida; Zuo, Hong

    2017-01-01

    In the current study, we evaluate the equivalent stiffness of peritubular reinforcement effect (PRE) of porous dentine optimized by the thickness of peritubular dentine (PTD). Few studies to date have evaluated or quantitated the effect of PRE on composite dentine. The miscrostructure of porous dentine is captured by scanning electron microscope images, and then finite element modeling is used to quantitate the deformation and stiffness of the porous dentine structure. By optimizing the radius of PTD and dentine tubule (DT), the proposed FE model is able to demonstrate the effect of peritubular reinforcement on porous dentine stiffness. It is concluded that the dentinal equivalent stiffness is reduced and degraded with the increase of the radius of DT (i.e., porosity) in the certain ratio value of Ep/Ei and certain radius of PTD, where Ep is the PTD modulus and Ei is the intertubular dentine modulus. So in order to ensure the whole dentinal equivalent stiffness is not loss, the porosity should get some value while the Ep/Ei is certain. Thus, PTD prevents the stress concentration around DTs and reduces the risk of DTs failure. Mechanically, the overall role of PTD appears to enhance the stiffness of the dentine composite structure. These results provide some new and significant insights into the biological evolution of the optimal design for the porous dentine microstructure. These findings on the biological microstructure design of dentine materials are applicable to other engineering structural designs aimed at increasing the overall structural strength.

  2. Refrigeration Test Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The enclosed and environmentally controlled chamber is able to test four units (single-phase) simultaneously at conditions ranging from tundra to desert temperatures...

  3. DORIOT CLIMATIC CHAMBERS

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers reproduce environmental conditions occurring anywhere around the world. They provide an invaluable service by significantly reducing the...

  4. Regulation of reactionary dentin formation by odontoblasts in response to polymicrobial invasion of dentin matrix

    Science.gov (United States)

    Charadram, Nattida; Farahani, Ramin M; Harty, Derek; Rathsam, Catherine; Swain, Michael V; Hunter, Neil

    2011-01-01

    Odontoblast synthesis of dentin proceeds through discrete but overlapping phases characterized by formation of a patterned organic matrix followed by remodelling and active mineralization. Microbial invasion of dentin in caries triggers an adaptive response by odontoblasts, culminating in formation of a structurally altered reactionary dentin, marked by biochemical and architectonic modifications including diminished tubularity. Scanning electron microscopy of the collagen framework in reactionary dentin revealed a radically modified yet highly organized meshwork as indicated by fractal and lacunarity analyses. Immuno-gold labelling demonstrated increased density and regular spatial distribution of dentin sialoprotein (DSP) in reactionary dentin. DSP contributes putative hydroxyapatite nucleation sites on the collagen scaffold. To further dissect the formation of this altered dentin matrix, the associated enzymatic machinery was investigated. Analysis of extracted dentin matrix indicated increased activity of matrix metalloproteinase-2 (MMP-2) in the reactionary zone referenced to physiologic dentin. Likewise, gene expression analysis of micro-dissected odontoblast layer revealed up-regulation of MMP-2. Parallel up-regulation of tissue inhibitor of metalloproteinase-2 (TIMP-2) and membrane type 1- matrix metalloproteinase (MT1-MMP) was observed in response to caries. Next, modulation of odontoblastic dentinogenic enzyme repertoire was addressed. In the odontoblast layer expression of Toll-like receptors was markedly altered in response to bacterial invasion. In carious teeth TLR-2 and the gene encoding the corresponding adaptor protein MyD88 were down-regulated whereas genes encoding TLR-4 and adaptor proteins TRAM and Mal/TIRAP were up-regulated. TLR-4 signalling mediated by binding of bacterial products has been linked to up-regulation of MMP-2. Further, increased expression of genes encoding components of the TGF-β signalling pathway, namely SMAD-2 and SMAD-4

  5. Effect of different calcium phosphate scaffold ratios on odontogenic differentiation of human dental pulp cells.

    Science.gov (United States)

    AbdulQader, Sarah Talib; Kannan, Thirumulu Ponnuraj; Rahman, Ismail Ab; Ismail, Hanafi; Mahmood, Zuliani

    2015-04-01

    Calcium phosphate (CaP) scaffolds have been widely and successfully used with osteoblast cells for bone tissue regeneration. However, it is necessary to investigate the effects of these scaffolds on odontoblast cells' proliferation and differentiation for dentin tissue regeneration. In this study, three different hydroxyapatite (HA) to beta tricalcium phosphate (β-TCP) ratios of biphasic calcium phosphate (BCP) scaffolds, BCP20, BCP50, and BCP80, with a mean pore size of 300μm and 65% porosity were prepared from phosphoric acid (H2PO4) and calcium carbonate (CaCO3) sintered at 1000°C for 2h. The extracts of these scaffolds were assessed with regard to cell viability and differentiation of odontoblasts. The high alkalinity, more calcium, and phosphate ions released that were exhibited by BCP20 decreased the viability of human dental pulp cells (HDPCs) as compared to BCP50 and BCP80. However, the cells cultured with BCP20 extract expressed high alkaline phosphatase activity and high expression level of bone sialoprotein (BSP), dental matrix protein-1 (DMP-1), and dentin sialophosphoprotein (DSPP) genes as compared to that cultured with BCP50 and BCP80 extracts. The results highlighted the effect of different scaffold ratios on the cell microenvironment and demonstrated that BCP20 scaffold can support HDPC differentiation for dentin tissue regeneration. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Effects of dental trauma on the pulp.

    Science.gov (United States)

    Love, R M

    1997-05-01

    Infection of the root canal system following dental trauma induces pulp and periapical disease and prevents healing of previously healthy pulp. A clinical goal in treating trauma is the maintenance of pulp vitality, and clinicians should be aware of factors that influence pulp healing. The learning objective of this article is to review the factors and techniques that influence pulp vitality and examine the influence pulp has on the healing of adjacent tissues. The potential routes for bacterial infection of the root canal system are discussed, with the clinical crown as the primary portal of entry. Uncomplicated and complicated crown fractures, as well as the crown-root and root fractures, are reviewed. Complications in pulp healing include canal obliteration, disturbed root development, apexogenesis, apexification, and the various forms of resorption.

  7. Differentiation potential of STRO-1+ dental pulp stem cells changes during cell passaging

    Directory of Open Access Journals (Sweden)

    Wang Ruoning

    2010-05-01

    Full Text Available Abstract Background Dental pulp stem cells (DPSCs can be driven into odontoblast, osteoblast, and chondrocyte lineages in different inductive media. However, the differentiation potential of naive DPSCs after serial passaging in the routine culture system has not been fully elucidated. Results DPSCs were isolated from human/rat dental pulps by the magnetic activated cell sorting based on STRO-1 expression, cultured and passaged in the conventional culture media. The biological features of STRO-1+ DPSCs at the 1st and 9th passages were investigated. During the long-term passage, the proliferation ability of human STRO-1+ DPSCs was downregulated as indicated by the growth kinetics. When compared with STRO-1+ DPSCs at the 1st passage (DPSC-P1, the expression of mature osteoblast-specific genes/proteins (alkaline phosphatase, bone sialoprotein, osterix, and osteopontin, odontoblast-specific gene/protein (dentin sialophosphoprotein and dentin sialoprotein, and chondrocyte-specific gene/protein (type II collagen was significantly upregulated in human STRO-1+ DPSCs at the 9th passage (DPSC-P9. Furthermore, human DPSC-P9 cells in the mineralization-inducing media presented higher levels of alkaline phosphatase at day 3 and day 7 respectively, and produced more mineralized matrix than DPSC-P9 cells at day 14. In vivo transplantation results showed that rat DPSC-P1 cell pellets developed into dentin, bone and cartilage structures respectively, while DPSC-P9 cells can only generate bone tissues. Conclusions These findings suggest that STRO-1+ DPSCs consist of several interrelated subpopulations which can spontaneously differentiate into odontoblasts, osteoblasts, and chondrocytes. The differentiation capacity of these DPSCs changes during cell passaging, and DPSCs at the 9th passage restrict their differentiation potential to the osteoblast lineage in vivo.

  8. Nanoleakage patterns of four dentin bonding systems.

    Science.gov (United States)

    Li, H; Burrow, M F; Tyas, M J

    2000-01-01

    The purpose of this study was to evaluate the nanoleakage patterns of four dentin bonding systems. The dentin bonding systems used in this study were: Single Bond, One Coat Bond, Prime & Bond NT/Non Rinse Conditioner (NRC), and PermaQuik. Flat occlusal dentin surfaces from extracted human molars were finished with wet 600-grit silicon carbide paper, and bonded with one of the dentin bonding systems. After 24 h storage at 37 degrees C in water, margins were finished with polishing discs and the surrounding tooth surfaces coated with nail varnish. The samples were immersed in a 50% (w/v) solution of silver nitrate for 24 h, and exposed to photodeveloping solution for 8 h. The samples were cut longitudinally, polished, and mounted on stubs, carbon coated and observed in a Field Emission-SEM using backscattered electron mode. Different nanoleakage patterns were observed with the different adhesive systems. However, accumulations of silver particles were often noted at the base of the hybrid layer for all materials. Single Bond and One Coat Bond demonstrated uptake of silver particles both within the hybrid layer and the adhesive resin. Prime & Bond NT/NRC showed silver staining throughout almost the entire thickness of the hybrid layer. The leakage pattern of PermaQuik revealed loose silver deposition within the hybrid layer. The composition of each adhesive system may play a role in forming the different leakage patterns. The current dentin bonding systems used in this study do not achieve perfect sealing at the restoration/dentin interface, which may influence the durability of the bond to dentin.

  9. Concomitant multipotent and unipotent dental pulp progenitors and their respective contribution to mineralised tissue formation

    Directory of Open Access Journals (Sweden)

    S Dimitrova-Nakov

    2012-05-01

    Full Text Available Upon in vitro induction or in vivo implantation, the stem cells of the dental pulp display hallmarks of odontoblastic, osteogenic, adipogenic or neuronal cells. However, whether these phenotypes result from genuine multipotent cells or from coexistence of distinct progenitors is still an open question. Furthermore, determining whether a single cell-derived progenitor is capable of undergoing a differentiation cascade leading to tissue repair in situ is important for the development of cell therapy strategies. Three clonal pulp precursor cell lines (A4, C5, H8, established from embryonic ED18 first molars of mouse transgenic for a recombinant plasmid adeno-SV40, were induced to differentiate towards the odonto/osteogenic, chondrogenic or adipogenic programme. Expression of phenotypic markers of each lineage was evaluated by RT-PCR, histochemistry or immunocytochemistry. The clones were implanted into mandibular incisors or calvaria of adult mice. The A4 clone was capable of being recruited towards at least 3 mesodermal lineages in vitro and of contributing to dentin-like or bone formation, in vivo, thus behaving as a multipotent cell. In contrast, the C5 and H8 clones displayed a more restricted potential. Flow cytometric analysis revealed that isolated monopotent and multipotent clones could be distinguished by a differential expression of CD90. Altogether, isolation of these clonal lines allowed demonstrating the coexistence of multipotential and restricted-lineage progenitors in the mouse pulp. These cells may further permit unravelling specificities of the different types of pulp progenitors, hence facilitating the development of cell-based therapies of the dental pulp or other cranio-facial tissues.

  10. Enhanced Dentinogenesis of Pulp Progenitors by Early Exposure to FGF2.

    Science.gov (United States)

    Sagomonyants, K; Kalajzic, I; Maye, P; Mina, M

    2015-11-01

    Members of the fibroblast growth factor (FGF) family play essential and important roles in primary and reparative dentinogenesis. Although there appears to be a general agreement on the effects of FGF signaling on the proliferation of pulp cells, there are conflicting results regarding its effects on odontoblast differentiation. We recently examined the effects of continuous exposure of dental pulp cells to FGF2 and showed that the effects of FGF2 on differentiation of progenitor cells into odontoblasts were stage specific and dependent on the stage of cell maturity. The purpose of this study was to gain further insight into cellular and molecular mechanisms regulating the stimulatory effects of FGF2 on odontoblast differentiation. To do so, we examined the effects of early and limited exposure of pulp cells from a series of green fluorescent protein (GFP) reporter transgenic mice that display stage-specific activation of transgenes during odontoblast differentiation to FGF2. Our results showed that early and limited exposure of pulp cells to FGF2 did not have significant effects on the extent of mineralization but induced significant increases in the expression of Dmp1 and Dspp and the number of DMP1-GFP(+) and DSPP-Cerulean(+) odontoblasts. Our results also showed that the stimulatory effects of FGF2 on odontoblast differentiation were mediated through FGFR/MEK/Erk1/2 signaling, increases in Bmp2, and activation of the BMP/BMPR signaling pathway. These observations show that early and limited exposure of pulp cells to FGF2 alone promotes odontoblast differentiation and provides critical insight for applications of FGF2 in dentin regeneration.

  11. Clinical and radiographic evaluation of indirect pulp treatment with MTA and calcium hydroxide in primary teeth (in-vivo study

    Directory of Open Access Journals (Sweden)

    Vimi George

    2015-01-01

    Full Text Available Objectives: Clinical and radiographic effects of mineral trioxide aggregate (white MTA and calcium hydroxide (Dycal in indirect pulp treatment (IPT of primary teeth over a period of 6 months. Materials and Methods: A clinical trial with sample size of 40 primary molars between the age group of 5-9 years, of which, 20 teeth were considered, each for MTA and Dycal. Measurements on the digitized radiographs were performed at baseline, third and sixth month, increase in dentin was then measured using Corel Draw software. Result: Independent t-test had indicated that at the end of 3 months and 6 months, a statistically significant increase in dentin thickness with both MTA and Dycal (P-value ≤ 0.001 was found. Within the MTA group, the thickness of dentin formed was 0.089 mm ± 0.031 mm at first 3 months and 0.055 ± 0.022 mm at the second 3 months, (P ≤ 0.001 evaluated using paired t-test. In the Dycal group, increment in dentin deposited was 0.068 mm at the first 3 months and second 3 months, it was 0.030 mm (P-value ≤ 0.001. Conclusion: Clinically and radiographically, MTA is superior to Dycal as a good IPT medicament in primary teeth.

  12. Pulp response in primary teeth with deep residual caries treated with silver fluoride and glass ionomer cement ('atraumatic' technique)

    Science.gov (United States)

    Gotjamanos, T

    1996-10-01

    Histological assessment of the dental pulps of 55 carious primary teeth was carried out 3 to 58 months after treatment by the 'atraumatic' technique involving application of 40 per cent silver fluoride to residual caries followed by restoration with glass ionomer cement. Fifty of the 55 teeth examined showed a favourable pulpal response, inducing presence of abundant reparative dentine and a wide odontoblast layer. Histological comparisons were made between these teeth and others not treated with silver fluoride but restored with glass ionomer cement, amalgam or zinc oxide and eugenol. Possible mechanisms of the action of silver fluoride in arresting residual caries are discussed. The question of whether or not treatment of carious dentine with silver fluoride represents a biologically acceptable clinical procedure cannot be answered on the basis of pulpal histology alone. The very high concentration of fluoride in commercial preparations of silver fluoride raises several questions concerning its clinical safety.

  13. DELPHI time projection chamber

    CERN Multimedia

    1989-01-01

    The time projection chamber is inserted inside the central detector of the DELPHI experiment. Gas is ionised in the chamber as a charged particle passes through, producing an electric signal from which the path of the particle can be found. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  14. Fluidized bed combustion chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kullendorff, A.; Wikner, J.

    1985-03-25

    The chamber is confined in a pressure vessel. The lower part of the chamber has tilted parallel gutters up to the height of the fluidized bed. The slope of the gutter walls is 5 degrees-15 degrees and the top area of the gutters is 1.3 to 3 times larger than their bottom.

  15. Target chambers for gammashpere

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Falout, J.W.; Nardi, B.G. [and others

    1995-08-01

    One of our responsibilities for Gammasphere, was designing and constructing two target chambers and associated beamlines to be used with the spectrometer. The first chamber was used with the early implementation phase of Gammasphere, and consisted of two spun-Al hemispheres welded together giving a wall thickness of 0.063 inches and a diameter of 12 inches.

  16. Climatic chamber ergometer

    CSIR Research Space (South Africa)

    Atkins, AR

    1968-01-01

    Full Text Available The design and calibration of an ergometer for exercising subjects during calorimetric studies in the climate chamber, are described. The ergometer is built into the climatic chamber and forms an integral part of the whole instrumentation system foe...

  17. BEBC bubble chamber

    CERN Multimedia

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  18. The Mobile Chamber

    Science.gov (United States)

    Scharfstein, Gregory; Cox, Russell

    2012-01-01

    A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

  19. CHAMBER OF COMMERCE INFORMATION

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Experience Japan The Japanese Chamber of Commerce and Industry will further promote its Japan-experience program and seek cooperation with various Chinese institutions.Between early May and June 2007,the chamber organized a Chinese college student delegation to Japan with the support from its members in China.

  20. Role of Dentin MMPs in Caries Progression and Bond Stability

    OpenAIRE

    A. Mazzoni; Tjäderhane, L.; Checchi, V.; Di Lenarda, R.; Salo, T.; Tay, F.R.; Pashley, D.H.; Breschi, L

    2015-01-01

    Dentin can be described as a biological composite with collagen matrix embedded with nanosized hydroxyapatite mineral crystallites. Matrix metalloproteinases (MMPs) and cysteine cathepsins are families of endopeptidases. Enzymes of both families are present in dentin and collectively capable of degrading virtually all extracellular matrix components. This review describes these enzymes and their presence in dentin, mainly focusing on their role in dentin caries pathogenesis and loss of collag...

  1. [Influence of different dentin depths on microtensile bond strength of two dentin adhesive systems].

    Science.gov (United States)

    Zheng, Tie-li; Huang, Cui; Zheng, Zhi-xing

    2009-10-01

    To determine the microtensile bond strength of two adhesives systems to either superficial or deep dentin. The crowns extracted human premolars were transversally sectioned next to the occlusal DEJ to expose flat dentin surfaces. The surfaces were bonded with: (1)two-step, total-etch adhesive Prime&Bond NT (PB),(2)wo-step, self-etching adhesive FL-Bond (FB), according to manufacturers' directions. Composite build-ups were constructed incrementally. After storage for 24 hours in water at 37 degrees, the teeth were longitudinally sectioned in the "x" and "y" directions to obtain bonded sticks with a cross-sectional area of 0.81mm(2) with a slow-speed diamond saw. The remaining dentin thickness (RDT) was measured to assess the superficial dentin group (RDT> or =3mm) and the deep dentin group (RDT0.05). No cohesive failure was observed in either superficial or deep dentin. Most of the failure was adhesive failure. From this study, it can be concluded that different dentin depths can not influence the microtensile bond strengths of Prime&Bond NT and FL-Bond adhesive systems.

  2. Scanning electron microscopy and dentinal permeability analysis of smear layer.

    Science.gov (United States)

    Prati, C; Mongiorgi, R; Pashley, D H; Riva di Sanseverino, L

    1991-05-01

    The aim of the present study was to evaluate the surface morphology and the permeability of dentine after different acid treatments: polyacrylic acid, maleic acid, phosphoric acid and saline solution as control. Dentine permeability was expressed as hydraulic conductance. All the acid treatments removed the smear layer and increased the dentine permeability.

  3. Human Pulp Responses to Partial Pulpotomy Treatment with TheraCal as Compared with Biodentine and ProRoot MTA: A Clinical Trial.

    Science.gov (United States)

    Bakhtiar, Hengameh; Nekoofar, Mohammad Hossein; Aminishakib, Pouyan; Abedi, Fatemeh; Naghi Moosavi, Fereshteh; Esnaashari, Ehsan; Azizi, Arash; Esmailian, Samar; Ellini, Mohammad Reza; Mesgarzadeh, Vahid; Sezavar, Mehdi; About, Imad

    2017-08-16

    Questions exist regarding the efficacy of resin-containing materials such as TheraCal directly applied on the pulp. This study sought to investigate the clinical efficacy of TheraCal as compared with Biodentine and ProRoot mineral trioxide aggregate (MTA) for partial pulpotomy. In this clinical trial, partial pulpotomy was performed for 27 sound human maxillary and mandibular third molars scheduled for extraction. The teeth were randomly divided into 3 groups (n = 9) and underwent partial pulpotomy with TheraCal, Biodentine, and ProRoot MTA. The teeth were then restored with glass ionomer cement. Clinical and electric pulp tests were performed after 1 and 8 weeks. The teeth were radiographed and extracted at 8 weeks. Histologic sections were prepared and analyzed for pulp inflammation and dentinal bridge formation. Data were analyzed by using one-way analysis of variance. Clinical examination showed no sensitivity to heat, cold, or palpation in ProRoot MTA and Biodentine groups. Two patients in TheraCal group (20%) reported significant pain at 1 week. Periapical radiographs showed no periapical pathology, and electric pulp test revealed a normal pulp response with no hypersensitivity. Inflammation was absent with all materials at 8 weeks. Normal pulp organization was seen in 33.33% of the teeth in ProRoot MTA, 11.11% in TheraCal, and 66.67% in Biodentine group (P = .06). Biodentine group showed complete dentinal bridge formation in all teeth, whereas this rate was 11% and 56% in TheraCal and ProRoot MTA groups, respectively (P = .001). Overall, Biodentine and MTA performed better than TheraCal when used as partial pulpotomy agent and presented the best clinical outcomes. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Plasma treatment of dentin surfaces for improving self-etching adhesive/dentin interface bonding.

    Science.gov (United States)

    Dong, Xiaoqing; Li, Hao; Chen, Meng; Wang, Yong; Yu, Qingsong

    2015-06-01

    This study is to evaluate plasma treatment effects on dentin surfaces for improving self-etching adhesive and dentin interface bonding. Extracted unerupted human third molars were used after crown removal to expose dentin. One half of each dentin surface was treated with atmospheric non-thermal argon plasmas, while another half was untreated and used as the same tooth control. Self-etching adhesive and universal resin composite was applied to the dentin surfaces as directed. After restoration, the adhesive-dentin bonding strength was evaluated by micro-tensile bonding strength (μTBS) test. Bonding strength data was analyzed using histograms and Welch's t-test based on unequal variances. μTBS test results showed that, with plasma treatment, the average μTBS value increased to 69.7±11.5 MPa as compared with the 57.1±17.5 MPa obtained from the untreated controls. After 2 months immersion of the restored teeth in 37 °C phosphate buffered saline (PBS), the adhesive-dentin bonding strengths of the plasma-treated specimens slightly decreased from 69.7±11.5 MPa to 63.9±14.4 MPa, while the strengths of the untreated specimens reduced from 57.1±17.5 MPa to 48.9±14.6 MPa. Water contact angle measurement and scanning electron microscopy (SEM) examination verified that plasma treatment followed by water rewetting could partially open dentin tubules, which could enhance adhesive penetration to form thicker hybrid layer and longer resin tags and consequently improve the adhesive/dentin interface quality.

  5. Plasma treatment of dentin surfaces for improving self-etching adhesive/dentin interface bonding

    Science.gov (United States)

    Dong, Xiaoqing; Li, Hao; Chen, Meng; Wang, Yong; Yu, Qingsong

    2015-01-01

    This study is to evaluate plasma treatment effects on dentin surfaces for improving self-etching adhesive and dentin interface bonding. Extracted unerupted human third molars were used after crown removal to expose dentin. One half of each dentin surface was treated with atmospheric non-thermal argon plasmas, while another half was untreated and used as the same tooth control. Self-etching adhesive and universal resin composite was applied to the dentin surfaces as directed. After restoration, the adhesive-dentin bonding strength was evaluated by micro-tensile bonding strength (μTBS) test. Bonding strength data was analyzed using histograms and Welch’s t-test based on unequal variances. μTBS test results showed that, with plasma treatment, the average μTBS value increased to 69.7±11.5 MPa as compared with the 57.1±17.5 MPa obtained from the untreated controls. After 2 months immersion of the restored teeth in 37 °C phosphate buffered saline (PBS), the adhesive-dentin bonding strengths of the plasma-treated specimens slightly decreased from 69.7±11.5 MPa to 63.9±14.4 MPa, while the strengths of the untreated specimens reduced from 57.1±17.5 MPa to 48.9±14.6 MPa. Water contact angle measurement and scanning electron microscopy (SEM) examination verified that plasma treatment followed by water rewetting could partially open dentin tubules, which could enhance adhesive penetration to form thicker hybrid layer and longer resin tags and consequently improve the adhesive/dentin interface quality. PMID:26273561

  6. Evaluation of reparative dentin formation of ProRoot MTA, Biodentine and BioAggregate using micro-CT and immunohistochemistry

    Science.gov (United States)

    Kim, Jia; Song, Young-Sang; Min, Kyung-San; Kim, Sun-Hun; Koh, Jeong-Tae

    2016-01-01

    Objectives The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). Materials and Methods Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). Results On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. Conclusions Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA. PMID:26877988

  7. Optimum dose of 2-hydroxyethyl methacrylate based bonding material on pulp cells toxicity

    Directory of Open Access Journals (Sweden)

    Widya Saraswati

    2010-06-01

    Full Text Available Background: 2-hydroxyethyl methacrylate (HEMA, one type of resins commonly used as bonding base material, is commonly used due to its advantageous chemical characteristics. Several preliminary studies indicated that resin is a material capable to induce damage in dentin-pulp complex. It is necessary to perform further investigation related with its biological safety for hard and soft tissues in oral cavity. Purpose: The author performed an in vitro test to find optimum dose of HEMA resin monomer that may induce toxicity in pulp fibroblast cells. Method: The method of this study was experimental laboratory with post test control group design. Primary cell culture was made from dental pulp fibroblast cells, and was given with HEMA resin bonding material in various concentrations (5 µg/ml–2560 µg/ml, and then subjected to toxicity test (MTT assay. Result: HEMA optimum concentration was 320 µg/ml to induce cytotoxicity in pulp fibroblast cells. Conclusion: The used of HEMA - base bonding material with the concentration of 200 µg/ml may induced pulp fibroblas cell toxicity.Latar belakang: Keberhasilan suatu bahan bonding secara klinis tergantung pada kandungan fisik, kimia dan keamanan secara biologis. HEMA (2-hydroxyethyl methacrylate adalah bahan resin yang paling banyak digunakan karena memiliki sifat fisik-kimia yang baik. Beberapa penelitian pendahuluan menyebutkan bahwa resin merupakan bahan yang mampu menyebabkan gangguan pada kompleks dentin pulpa sehingga perlu dilakukan penelitian lebih lanjut menyangkut segi keamanan secara biologis bagi jaringan keras dan jaringan lunak di rongga mulut. Tujuan: Penelitian ini akan menguji secara in vitro (pada kultur sel fibroblas pulpa gigi untuk mengetahui dosis optimal monomer resin HEMA yang dapat menyebabkan toksisitas pada sel fibroblas pulpa. Metode: Metode penelitian ini adalah eksperimental laboratoris dengan rancangan penelitian post test control group design. Kultur sel primer dibuat dari

  8. Investigation of dental pulp stem cells isolated from discarded human teeth extracted due to aggressive periodontitis.

    Science.gov (United States)

    Sun, Hai-Hua; Chen, Bo; Zhu, Qing-Lin; Kong, Hui; Li, Qi-Hong; Gao, Li-Na; Xiao, Min; Chen, Fa-Ming; Yu, Qing

    2014-11-01

    Recently, human dental pulp stem cells (DPSCs) isolated from inflamed dental pulp tissue have been demonstrated to retain some of their pluripotency and regenerative potential. However, the effects of periodontal inflammation due to periodontitis and its progression on the properties of DPSCs within periodontally compromised teeth remain unknown. In this study, DPSCs were isolated from discarded human teeth that were extracted due to aggressive periodontitis (AgP) and divided into three experimental groups (Groups A, B and C) based on the degree of inflammation-induced bone resorption approaching the apex of the tooth root before tooth extraction. DPSCs derived from impacted or non-functional third molars of matched patients were used as a control. Mesenchymal stem cell (MSC)-like characteristics, including colony-forming ability, proliferation, cell cycle, cell surface antigens, multi-lineage differentiation capability and in vivo tissue regeneration potential, were all evaluated in a patient-matched comparison. It was found that STRO-1- and CD146-positive DPSCs can be isolated from human teeth, even in very severe cases of AgP. Periodontal inflammation and its progression had an obvious impact on the characteristics of DPSCs isolated from periodontally affected teeth. Although all the isolated DPSCs in Groups A, B and C showed decreased colony-forming ability and proliferation rate (P biomaterials were transplanted directly into an ectopic transplantation model. However, when cell-seeded scaffolds were placed in the root fragments of human teeth, all the cells formed significant dentin- and pulp-like tissues. The ability of DPSCs to generate dental tissues decreased when the cells were isolated from periodontally compromised teeth (P < 0.05). Again, increased periodontal destruction was not necessarily followed by a decrease in the amount of dentin- and pulp-like tissue formed. These findings provide preliminary evidence that periodontally compromised teeth might

  9. Can Dental Pulp Calcification Predict the Risk of Ischemic Cardiovascular Disease?

    Directory of Open Access Journals (Sweden)

    Leila Khojastepour

    2013-01-01

    Full Text Available Objective: To report the association of pulp calcification with that of cardiovascular disease (CVD using digital panoramic dental radiographs.Materials and Methods: Digital panoramic radiographs of patients referred from the angiography department were included if the patient was under 55 years old and had non-restored or minimally restored molars and canines. An oral and maxillofacial radiologist evaluated the images for pulpal calcifications in the selected teeth. The sensitivity, specificity, positive predictive value and negative predictive value of panoramic radiography in predicting CVD were calculated.Results: Out of 122 patients who met the criteria, 68.2% of the patients with CVD had pulp chamber calcifications. Pulp calcification in panoramic radiography had a sensitivity of 68.9% to predict CVD.Conclusion: This study demonstrates that patients with CVD show an increased incidence of pulp calcification compared with healthy patients. The findings suggest that pulp calcification on panoramic radiography may have possibilities for use in CVD screening.

  10. Pulp treatment for extensive decay in primary teeth.

    Science.gov (United States)

    Smaïl-Faugeron, Violaine; Courson, Frédéric; Durieux, Pierre; Muller-Bolla, Michele; Glenny, Anne-Marie; Fron Chabouis, Helene

    2014-08-06

    . We included 47 trials (3910 randomised teeth) compared to three trials in the previous version of the review published in 2003. All trials were single centre and small sized (median number of randomised teeth 68). Overall, the risk of bias was low in only one trial with all other trials being at unclear or high risk of bias. The overall quality of the evidence was low. The 47 trials examined 53 different comparisons: 25 comparisons between different medicaments/techniques for pulpotomy, 13 comparisons between different medicaments for pulpectomy, 13 comparisons between different medicaments for direct pulp capping and two comparisons between pulpotomy and pulpectomy. Regarding pulpotomy, 14 trials compared mineral trioxide aggregate (MTA) with formocresol (FC). MTA reduced both clinical and radiological failures at six, 12 and 24 months, although the difference was not statistically significant. MTA also showed favourable results for all secondary outcomes measured, although again, differences between MTA and FC were not statistically significant (with the exception of pathological root resorption at 24 months and dentine bridge formation at six months). MTA showed favourable results compared with calcium hydroxide (CH) (two trials) for all outcomes measured, but the differences were not statistically significant (with the exception of radiological failure at 12 months). When comparing MTA with ferric sulphate (FS) (three trials), MTA had statistically significantly fewer clinical, radiological and overall failures at 24 months. This difference was not shown at six or 12 months.FC was compared with CH in seven trials and with FS in seven trials. There was a statistically significant difference in favour of FC for clinical failure at six and 12 months, and radiological failure at six, 12 and 24 months. FC also showed favourable results for all secondary outcomes measured, although differences between FC and CH were not consistently statistically significant across

  11. Effect of self-etching adhesives on dentin permeability in a fluid flow model.

    Science.gov (United States)

    Grégoire, Geneviève; Guignes, Philippe; Millas, Arlette

    2005-01-01

    Numerous self-etching bonding systems exist, with composition differing from one product to another. It is important for the clinician to know if they are all equally effective, and whether they provide an effective seal between dentin and restorative materials. This study was designed to measure the hydraulic conductance of physiologic saline across dentin after application of various self-etching bonding systems or of a 1-bottle adhesive system preceded by a phosphoric acid etch. One hundred extracted noncarious human third molars from patients 18-25 years old were used for this study. Dentin disks were cut from crown segments parallel to the occlusal surface at the top of the pulp cavity. The 100 disks, each 1 mm thick, were divided into 10 groups (n=10 per group), each of which was treated with 1 of 9 self-etching systems-AdheSE, Adper Prompt L-Pop, Clearfil SE Bond, Etch & Prime 3.0, Prime & Bond NRC Nt, One-Up Bond F, optiBond solo Plus Self Etch, Prompt L-Pop, or Xeno III-or a control bonding system (Prime & Bond NT) preceded by a phosphoric acid etch. Hydraulic conductance, the volume of fluid transported across a known area of surface (0.28 cm2) per unit time under a unit pressure gradient (200 cm H2O), was analyzed for the adhesive systems using a fluid flow apparatus (Flodec). First, both sides of each specimen were etched with 36% phosphoric acid for 30 seconds, and the hydraulic conductance was measured every 30 seconds for 15 minutes. The initial set of measurements served as the reference value for each specimen. The measurements were repeated when a smear layer had been formed and, finally, after 1 of the 10 bonding systems had been applied. The data were analyzed using a 1-way ANOVA and Duncan's multiple range test (alpha=.05). The control 1-bottle adhesive used with a phosphoric acid pre-etch did not provide the largest reduction in penetration (42.3%). The greatest mean reduction (68.9%, PAdheSE, 58.2%; Etch & Prime 3.0, 56.8%; Adper Prompt L

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

    Science.gov (United States)

    MOLLICA, Fernanda Brandão; TORRES, Carlos Rocha Gomes; GONÇALVES, Sergio Eduardo de Paiva; MANCINI, †Maria Nadir Gasparoto

    2012-01-01

    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. PMID:23032207

  13. 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.

  14. Culture medium modulates the behaviour of human dental pulp-derived cells: Technical Note

    Directory of Open Access Journals (Sweden)

    S Lopez-Cazaux

    2006-02-01

    Full Text Available In vitro approaches have extensively been developed to study reparative dentinogenesis. While dental pulp is a source of unidentified progenitors able to differentiate into odontoblast-like cells, we investigated the effect of two media; MEM (1.8mM Ca and 1mM Pi and RPMI 1640 (0.8mM Ca and 5mM Pi on the behaviour of human dental pulp cells. Our data indicate that MEM significantly increased cell proliferation and markedly enhanced the proportion of -smooth muscle actin positive cells, which represent a putative source of progenitors able to give rise to odontoblast-like cells. In addition, MEM strongly stimulated alkaline phosphatase activity and was found to induce expression of transcripts encoding dentin sialophosphoprotein, an odontoblastic marker, without affecting that of parathyroid hormone/parathyroid hormone related protein-receptor and osteonectin. In conclusion, these observations demonstrate that not only proliferation but also differentiation into odontoblast-like cells was induced by rich calcium and poor phosphate medium (MEM as compared to RPMI 1640. This study provides important data for the determination of the optimal culture conditions allowing odontoblast-like differentiation in human pulp cell culture.

  15. Expression of DMP-1 in the human pulp tissue using low level laser therapy

    Science.gov (United States)

    Lourenço Neto, Natalino; Teixeira Marques, Nádia Carolina; Fernandes, Ana Paula; Oliveira Rodini, Camila; Cruvinel Silva, Thiago; Moreira Machado, Maria Aparecida Andrade; Marchini Oliveira, Thais

    2015-09-01

    This study aimed to evaluate the effects of low-level laser therapy (LLLT) on DMP-1 expression in pulp tissue repair of human primary teeth. Twenty mandibular primary molars were randomly assigned into the following groups: Group I—Buckley’s Formocresol (FC); Group II—Calcium Hydroxide (CH); Group III—LLLT + CH and Group IV—LLLT + Zinc oxide/Eugenol. The teeth at the regular exfoliation period were extracted for histological analysis and immunolocalization of DMP-1. Descriptive analysis was performed on the dentin pulp complex. Histopathological assessment showed internal resorption in group FC. Groups CH and LLLT + CH provided better pulpal repair due to the absence of inflammation and the formation of hard tissue barrier. These two groups presented odontoblastic layer expressing DMP-1. According to this study, low level laser therapy preceding the use of calcium hydroxide exhibited satisfactory bio-inductive activity on pulp tissue repair of human primary teeth. However, other histological and cellular studies are needed to confirm the laser tissue action and efficacy.

  16. Effect of different calcium phosphate scaffold ratios on odontogenic differentiation of human dental pulp cells

    Energy Technology Data Exchange (ETDEWEB)

    AbdulQader, Sarah Talib [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Department of Pedodontic and Preventive Dentistry, College of Dentistry, University of Baghdad, Baghdad (Iraq); Kannan, Thirumulu Ponnuraj, E-mail: kannan@usm.my [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Human Genome Centre, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Rahman, Ismail Ab [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Ismail, Hanafi [School of Materials and Minerals Resource Engineering, Universiti Sains Malaysia, 14300 Penang (Malaysia); Mahmood, Zuliani [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

    2015-04-01

    Calcium phosphate (CaP) scaffolds have been widely and successfully used with osteoblast cells for bone tissue regeneration. However, it is necessary to investigate the effects of these scaffolds on odontoblast cells' proliferation and differentiation for dentin tissue regeneration. In this study, three different hydroxyapatite (HA) to beta tricalcium phosphate (β-TCP) ratios of biphasic calcium phosphate (BCP) scaffolds, BCP20, BCP50, and BCP80, with a mean pore size of 300 μm and 65% porosity were prepared from phosphoric acid (H{sub 2}PO{sub 4}) and calcium carbonate (CaCO{sub 3}) sintered at 1000 °C for 2 h. The extracts of these scaffolds were assessed with regard to cell viability and differentiation of odontoblasts. The high alkalinity, more calcium, and phosphate ions released that were exhibited by BCP20 decreased the viability of human dental pulp cells (HDPCs) as compared to BCP50 and BCP80. However, the cells cultured with BCP20 extract expressed high alkaline phosphatase activity and high expression level of bone sialoprotein (BSP), dental matrix protein-1 (DMP-1), and dentin sialophosphoprotein (DSPP) genes as compared to that cultured with BCP50 and BCP80 extracts. The results highlighted the effect of different scaffold ratios on the cell microenvironment and demonstrated that BCP20 scaffold can support HDPC differentiation for dentin tissue regeneration. - Highlights: • BCPs of different HA/β-TCP ratios influence cell microenvironment. • BCP20 decreases cell viability of HDPCs as compared to BCP50 and BCP80. • HDPCs cultured with BCP20 express highest ALP activity. • HDPCs cultured with BCP20 up-regulate BSP, DMP-1 and DSPP gene expressions. • BCP20 can support HDPC differentiation for dentin tissue regeneration.

  17. A mesoporous biomaterial for biomimetic crystallization in dentinal tubules without impairing the bonding of a self-etch resin to dentin

    Directory of Open Access Journals (Sweden)

    Yu-Chih Chiang

    2016-06-01

    Conclusion: CCMS-HP can be used to form a biomimetic barrier for prevention of dentin sensitivity because it neither impedes the bonding of SBU to dentin nor impairs the shear bonding strength between the SBU and dentin.

  18. Evaluation of a Commercially Available Hyaluronic Acid Hydrogel (Restylane) as Injectable Scaffold for Dental Pulp Regeneration: An In Vitro Evaluation.

    Science.gov (United States)

    Chrepa, Vanessa; Austah, Obadah; Diogenes, Anibal

    2017-02-01

    Regenerative endodontic procedures (REPs) are viable alternatives for treating immature teeth, yet these procedures do not predictably lead to pulp-dentin regeneration. A true bioengineering approach for dental pulp regeneration requires the incorporation of a scaffold conducive with the regeneration of the pulp-dentin complex. Several materials have been proposed as scaffolds for REPs; nonetheless, the majority are not eligible for immediate clinical chairside use. Thus, the aim of this study was to evaluate Restylane, a Food and Drug Administration-approved hyaluronic acid-based gel, as possible scaffold for REPs. Stem cells of the apical papilla (SCAP) were cultured either alone or in mixtures with either Restylane or Matrigel scaffolds. Groups were cultured in basal culture medium for 6, 24, and 72 hours, and cell viability was assessed. For the mineralizing differentiation experiments, groups were cultured in differentiation medium either for 7 days and processed for alkaline phosphatase activity or for 14 days and processed for gene expression by using quantitative reverse-transcription polymerase chain reaction. SCAP in basal medium served as control. Cell encapsulation in either Restylane or Matrigel demonstrated reduced cell viability compared with control. Nonetheless, cell viability significantly increased in the Restylane group in the course of 3 days, whereas it decreased significantly in the Matrigel group. Restylane promoted significantly greater alkaline phosphatase activity and upregulation of dentin sialophosphoprotein, dentin matrix acidic phosphoprotein-1, and matrix extracellular phosphoglycoprotein, compared with control. A Food and Drug Administration-approved hyaluronic acid-based injectable gel promoted SCAP survival, mineralization, and differentiation into an odontoblastic phenotype and may be a promising scaffold material for REPs. Published by Elsevier Inc.

  19. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  20. OPAL Jet Chamber Prototype

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

  1. [Functional morphology of pulp tissue].

    Science.gov (United States)

    Heine, H; Schaeg, G; Türk, R

    1989-01-01

    As compared with mesenchyme no genuine defense cells are developed in the tissue of the dental pulp and the nervous tissue. This is a further hint for the common development from ectoderm. The three dimensional meshwork of pulpa fibroblasts ("mesectoderm") is structured by elongated cell processes connected with each other by a variety of special cell junctions ("electronic cell coupling"). Metabolites from the microcirculation and neuropeptides from vegetative axons influence the activity of fibroblasts synthetizing groundsubstance. The meshwork of the groundsubstance has exclusion effects concerning molecules with a distinct molecular weight and charge. Thus a primitive defense system is established. With this the role of a newly described cell type of the dental pulp, the "lymphocytic pericyte" is discussed. Because of the poor capacity of the pulpa tissue for immunological reactions pathologically disorders may easily become chronically spreading their antigenic components throughout the body.

  2. Caffeine reduction in coffee pulp through silage.

    Science.gov (United States)

    Porres, C; Alvarez, D; Calzada, J

    1993-01-01

    Silage tests to study reductions of antiphysiological compounds (caffeine and polyphenols) of fresh coffee pulp during the anaerobic fermentation were done. A concrete silo divided in compartments, with a total capacity of 9 tons of fresh material was utilized. The silage periods ranged between 99-224 days and the following materials were ensiled: 1) coffee pulp, 2) coffee pulp with sugar cane molasses, 3) coffee pulp with a mixture of molasses and ammonia and 4) screw pressed coffee pulp with molasses. Reductions in caffeine, total polyphenols and condensed polyphenols ranged between 13-63%, 28-70% and 51-81% respectively. It was concluded that in the case of coffee pulp, silage presents and ideal method to preserve the material and partially reduce the contents of antiphysiological compounds.

  3. 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.

  4. [Pulp response to restorative materials].

    Science.gov (United States)

    Advokaat, J G

    1990-03-01

    Restorations may affect the pulp negatively, rather due to microleakage than to toxic properties of the materials used. Hyperalgesia occurs more frequently after restoration with composite resins than with amalgam, though the resins in contrast to amalgam may be bonded to the enamel margins. A number of recommendations are presented in order to minimize the marginal gap between cavity walls and amalgam and to prevent marginal fracture.

  5. Pilot-plant pulping studies on four abaca varieties. I. Soda pulping

    Energy Technology Data Exchange (ETDEWEB)

    Zerrudo, J.V.; Visperas, R.V.; Ballon, C.H.

    1981-01-01

    Cooking of spindle-stripped and decorticated abaca varieties with 13.5% NaOH for 2.5 hours at 170 degrees gave pulp in average yield of 69.1% and 60.9%, respectively. All the pulps had low permanganate numbers, indicating that they can be bleached easily. The strength properties of abaca pulp were related to the plant variety, and Sabahon variety gave pulp with best strength characteristics.

  6. Influence of post-bleaching time intervals on dentin bond strength Influência de tempos de espera pós-clareamento na resistência adesiva da dentina

    Directory of Open Access Journals (Sweden)

    Erica Cappelletto Nogueira Teixeira

    2004-03-01

    Full Text Available It has been reported that bond strength of resin to tooth structure can be reduced when the bonding procedure is carried out immediately after the bleaching treatment. This study evaluated the effect of bleaching of non-vital teeth bleaching on the shear bond strength (SBS of composite resin/bovine dentin interface and the influence of delaying the bonding procedures for different time intervals following internal bleaching. According to a randomized block design, composite resin cylinders (Z100/Single bond - 3M were bonded to the flattened dentin surface of two hundred and fifty-six teeth which had previously been subjected to four different treatments: SPH - sodium perborate + 30% hydrogen peroxide; SPW - sodium perborate + distilled wate