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Sample records for canal wall dentine

  1. Effects of the copper vapour laser radiation in the root canal wall dentine: in vitro experiment using scanning electron microscopy and stereoscopy

    International Nuclear Information System (INIS)

    Ten human uniradicular teeth had their crown removed along the cement-enamel junction and right away a proper chemical-surgical preparation of the radicular canals was done; the roots were longitudinally sectioned in order to allow the irradiation of the surfaces of the root canals wall dentine. The hemi-roots were separated in two groups: group I (control), with four hemi-roots, not irradiated; and group II, with 16 hemi-roots, subdivided in four sub-groups submitted to the following exposition time: 0,02 s; 0,05 s; 0,1 s and 0,5 s. A copper vapour laser was used with a 510,6 nm wavelength, total average power of 11 W in green and yellow emissions; average power of 6,5 W in green emission; pulse repetition rate of 16.000 Hz and pulse duration of 30 ns. The pulse energy (green line) is 0,4 mJ and the peak power 13,5 W. The laser cavity is unstable type (R1=3.900 mm and R2-250 mm). The focusing have focal length lens f1=250 mm and f2=150 mm. The beam quality is of the M2=5. The results obtained by scanning electron microscopy analysis showed the appearance of a cavity in the region of the laser beam incidence in the edges of this cavity, dentin was melt and resolidified presenting also cracks due to heat diffusion. Based on these results, we concluded that the size of the cavity formed in the dentin is directly proportional to the rate of exposure and, the more laser emission in the same area, more damage in the root canals wall dentin occurs. More studies need to be done with different exposition's time in order to obtain a safety protocol that does not cause injury in dental and support tissue. (author)

  2. 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.

  3. 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.

  4. Influence of the dentinal wall on the pH of sodium hypochlorite during root canal irrigation

    NARCIS (Netherlands)

    R.G. Macedo; N.P. Herrero; P. Wesselink; M. Versluis; L. van der Sluis

    2014-01-01

    Introduction The purpose of this study was to evaluate the influence of dentin on the pH levels of different concentrations of sodium hypochlorite (NaOCl) solutions over time and to evaluate if preconditioning of dentin with 17% EDTA or agitation of the NaOCl solution influences these pH levels. Met

  5. Influence of the Dentinal Wall on the pH of Sodium Hypochlorite during Root Canal Irrigation

    NARCIS (Netherlands)

    Macedo, Ricardo Gomes; Herrero, Noemi Pascual; Wesselink, Paul; Versluis, Michel; van der Sluis, Luc

    2014-01-01

    Introduction: The purpose of this study was to evaluate the influence of dentin on the pH levels of different concentrations of sodium hypochlorite (NaOCl) solutions over time and to evaluate if preconditioning of dentin with 17% EDTA or agitation of the NaOCl solution influences these pH levels. Me

  6. Canal Wall Reconstruction Mastoidectomy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To investigate the advantages of canal wall reconstruction (CWR) mastoidectomy, a single-stage technique for cholesteatoma removal and posterior external canal wall reconstruction, over the open and closed procedures in terms of cholesteatoma recurrence. Methods: Between June 2002 and December 2005, 38 patients (40 ears) with cholesteatoma were admited to Sun Yat-Sen Memorial Hospital and received surgical treatments. Of these patients, 25 were male with ages ranging between 11 and 60 years (mean = 31.6 years) and 13 were female with ages ranging between 20 and 65 years (mean = 38.8 years). Canal wall reconstruction (CWR)mastoidectomy was performed in 31 ears and canal wall down (CWD) mastoidectomy in 9 ears. Concha cartilage was used for ear canal wall reconstruction in 22 of the 31 CWR procedures and cortical mastoid bone was used in the remaining 9 cases. Results At 0.5 to 4 years follow up, all but one patients remained free of signs of cholesteatoma recurrence, i.e., no retraction pocket or cholesteatoma matrix. One patient, a smoker, needed revision surgery due to cholesteatoma recurrence 1.5 year after the initial operation. The recurrence rate was therefore 3.2% (1/31). Cholesteatoma recurrence was monitored using postoperative CT scans whenever possible. In the case that needed a revision procedure, a retraction pocket was identified by otoendoscopy in the pars flacida area that eventually evolved into a cholesteatoma. A pocket extending to the epitympanum filled with cholesteatoma matrix was confirmed during the revision operation, A decision to perform a modified mastoidectomy was made as the patient refused to quit smoking. The mean air-bone gap in pure tone threshold was 45 dB before surgery and 25 dB after (p < 0.05). There was no difference between using concha cartilage and cortical mastoid bone for the reconstruction regarding air-bone gap improvement, CT findings and otoendoscopic results. Conclusion CWR mastoidectomy can be used for

  7. Assessment Using AutoCAD Software of the Preparation of Dentin Walls in Root Canals Produced by 4 Different Endodontic Instrument Systems

    Directory of Open Access Journals (Sweden)

    Cristina Cabanillas

    2015-01-01

    Full Text Available Objectives. To compare the effectiveness of four instrument systems for preparing oval root canals: manual instrumentation (Step-Back technique, ProTaper Universal, ProTaper Next, and Wave One. Material and Methods. For the purpose of this assessment, 60 teeth extracted for orthodontic or periodontal reasons, specifically canines and premolars with full coronal and root anatomy, were used and 15 samples were assigned to each group. The section of the canals was compared before and after instrumenting and the section of untouched canal wall was measured using AutoCAD software. The data was analysed by means of Shapiro-Wilk, ANOVA, and Kruskal-Wallis tests. Results. In the apical third, 100% of the canals were prepared with all the systems. In the middle third, a p value of 0.5989 in the Kruskal-Wallis test was obtained, which indicates no significant difference between the groups. At the coronal third level, the results obtained revealed that Wave One had a significantly lower mean average than the rest (p<0.05. Conclusions. There are no differences between the various root canal instrument systems in the apical and middle thirds. At the coronal third level, Wave One system showed performance significantly worse than the rest, among which there were no differences.

  8. Interactions between root canal irrigants, sealers and dentin

    OpenAIRE

    Neelakantan, P.

    2016-01-01

    The objective of this thesis was to determine the interactions between root filling materials and root dentin and to investigate if root canal irrigating solutions had an impact on these interactions. The following outcomes were assessed in the studies encompassed in this thesis: (i) dislocation resistance of an epoxy resin based root canal sealer and tricalcium silicate based root canal sealers, (ii) the influence of irrigation protocols on the sealing ability and chemical interactions with ...

  9. Assessment of the wetting behavior of three different root canal sealers on root canal dentin

    OpenAIRE

    Muralidhar Tummala; Veeramachaneni Chandrasekhar; A Shashi Rashmi; Kundabala, M; Vasudev Ballal

    2012-01-01

    Aim: The objective of the present study was to evaluate and compare the wetting behavior of three different root canal sealers on the root canal dentin surface treated with irrigants and their combination. Materials and Methods: Decoronation and apical third resections of 27 extracted single-rooted human mandibular premolars were done. The roots were then split longitudinally into two halves, and randomly assigned into three treatment groups (n=18). The root dentin surfaces in Group1, Gro...

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

    Science.gov (United States)

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

    2015-11-01

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

  11. Assessment of the wetting behavior of three different root canal sealers on root canal dentin

    Directory of Open Access Journals (Sweden)

    Muralidhar Tummala

    2012-01-01

    Full Text Available Aim: The objective of the present study was to evaluate and compare the wetting behavior of three different root canal sealers on the root canal dentin surface treated with irrigants and their combination. Materials and Methods: Decoronation and apical third resections of 27 extracted single-rooted human mandibular premolars were done. The roots were then split longitudinally into two halves, and randomly assigned into three treatment groups (n=18. The root dentin surfaces in Group1, Group 2 and Group 3 were treated with 17% ethylene diamine tetra acetic acid (EDTA, 3% sodium hypochlorite (NaOCl and combination of 17% EDTA and 3% NaOCl, respectively. Each group was subdivided into three subgroups of 6 specimens each, depending on the the sealer used, i.e. sub group A. zinc oxide (ZnOE, sub group B. AH plus, subgroup C. Guttaflow sealer, respectively. The contact angle was measured using First Ten Angstroms (FTA 200 dynamic contact angle analyzer. Results: The contact angle values for AH Plus sealer were significantly lower when compared to the other two sealer groups. Conclusion: The wettability of AH Plus sealer on the root surface dentin was found to be better than Gutta-Flow and ZnOE sealer.

  12. Effects of the copper vapour laser radiation in the root canal wall dentine: in vitro experiment using scanning electron microscopy and stereoscopy; Efeitos da radiacao laser de vapor de cobre na parede de dentina de canais radiculares: estudo in vitro por meio de microscopia eletronica de varredura e microscopio estereoscopico

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Maria Claudia Garcia da

    2001-07-01

    Ten human uniradicular teeth had their crown removed along the cement-enamel junction and right away a proper chemical-surgical preparation of the radicular canals was done; the roots were longitudinally sectioned in order to allow the irradiation of the surfaces of the root canals wall dentine. The hemi-roots were separated in two groups: group I (control), with four hemi-roots, not irradiated; and group II, with 16 hemi-roots, subdivided in four sub-groups submitted to the following exposition time: 0,02 s; 0,05 s; 0,1 s and 0,5 s. A copper vapour laser was used with a 510,6 nm wavelength, total average power of 11 W in green and yellow emissions; average power of 6,5 W in green emission; pulse repetition rate of 16.000 Hz and pulse duration of 30 ns. The pulse energy (green line) is 0,4 mJ and the peak power 13,5 W. The laser cavity is unstable type (R{sub 1}=3.900 mm and R{sub 2}-250 mm). The focusing have focal length lens f{sub 1}=250 mm and f{sub 2}=150 mm. The beam quality is of the M{sup 2}=5. The results obtained by scanning electron microscopy analysis showed the appearance of a cavity in the region of the laser beam incidence in the edges of this cavity, dentin was melt and resolidified presenting also cracks due to heat diffusion. Based on these results, we concluded that the size of the cavity formed in the dentin is directly proportional to the rate of exposure and, the more laser emission in the same area, more damage in the root canals wall dentin occurs. More studies need to be done with different exposition's time in order to obtain a safety protocol that does not cause injury in dental and support tissue. (author)

  13. Vitality of Enterococcus faecalis inside dentinal tubules after five root canal disinfection methods

    Science.gov (United States)

    Vatkar, Niranjan Ashok; Hegde, Vivek; Sathe, Sucheta

    2016-01-01

    Aim: To compare the vitality of Enterococcus faecalis within dentinal tubules after subjected to five root canal disinfection methods. Materials and Methods: Dentin blocks (n = 60) were colonized with E. faecalis. After 4 weeks of incubation, the dentin blocks were divided into one control and five test groups (n = 10 each). The root canals of test groups were subjected to one of the disinfection methods, namely, normal saline (NS), sodium hypochlorite (NaOCl), chlorhexidine digluconate (CHX), neodymium-doped yttrium aluminum garnet (Nd: YAG) laser, and diode laser. The effect of disinfection methods was assessed by LIVE/DEAD BacLight stain under the confocal laser scanning microscopy to determine the “zone of dead bacteria” (ZDB). Mean values were calculated for ZDB and the difference between groups was established. Results: Penetration of E. faecalis was seen to a depth of >1000 μm. Viable bacteria were detected with NS irrigation. NaOCl and CHX showed partial ZDB. When the root canals were disinfected with Nd: YAG and diode lasers, no viable bacteria were found. Conclusion: E. faecalis has the ability to colonize inside dentinal tubules to a depth of >1000 μm. In contrast to conventional irrigants, both Nd: YAG and diode lasers were effective in eliminating the vitality of E. faecalis. NS, NaOCl, and CHX showed viable bacteria remaining in dentinal tubules. PMID:27656064

  14. The Effect of Root Canal Irrigation Solution on Flexural Strength of Dentin

    Directory of Open Access Journals (Sweden)

    Diatri Nari Ratih

    2013-07-01

    Full Text Available Objectives: This study was to investigate the effect of a variety of root canal irrigation solutions on flexural strength of dentin. Materials and Methods: Fifty intact, extracted human mandibular third molars were used in this study. Each tooth was sectioned using diamond cutting disc to create dentin bar (1x1 mm, with 7 mm in length. All dentin bars were randomly assigned into 5 groups of 10 each. Group 1, dentin bars were immersed in 5% NaOCl; group 2, in 2.5% NaOCl; group 3, in 15% EDTA; group 4, in 0.2% chlorhexidine gluconate (CHX; and group 5, in saline (as control respectively. Each group was immeresed for 2 hours. Each dentin bar was subjected to a three-point bend using MTS Universal Testing Machine to test the flexural strength. Data were analyzed using one way Anova, followed by Tukey's test performed at the 0.05 level of significance. Results: All irrigation solution have an effect on the flexural strength (P<0.05. EDTA caused the greatest effect on dentin mechanical properties, which revealed the lowest flexural strength (100.64±7.23. In contrast, 0.2% CHX generated the least influence on dentin mechanical properties, which demonstrated the greatest flexural strength (189.85±6.44. Conclusion: Root canal irrigation solution can induce effect on flexural strength of detin. Chlorhexidine gluconate demonstrates the best irrigation solution since it has a slight effect on dentinal mechanical properties, particularly flexural strength.DOI: 10.14693/jdi.v16i2.97

  15. Effect of the type of endodontic sealer on the bond strength between fiber post and root wall dentin.

    Directory of Open Access Journals (Sweden)

    Ramin Mosharraf

    2014-08-01

    Full Text Available An important factor that interferes with the bonding between the root canal wall and resin cement is the root canal sealer remnant. There is controversy about the effect of eugenol-containing sealers on the bond strength between resin cements and fiber post. The aim of this study was to evaluate the effect of the type of endodontic sealer on the bond strength of FRC posts cemented with resin cement to the root canal wall.In this in vitro study, 20 extracted mandibular first premolars were endodontically treated and divided into two groups according to the endodontic sealer used (n=10: G1: AH26 (Resin based; and G2: Endofill (Eugenol-based. After preparing post space, adhesive resin cement (Panavia F 2.0 was used for cementation of the fiber post to the root canal dentin. Three 3 mm thick slices were obtained from each root. The push-out test was performed with a cross-head speed of 1 mm/minute. Two-way ANOVA and Tukey post hoc tests were used for analyzing data (α=0.05.The two-way ANOVA showed that different root canal sealers (P=0.037 had significant effects on bond strength (BS, but root canal regions (P=0.811 and interaction between root canal sealers and root canal regions (P=0.258 had no significant effects on BS. Maximum and minimum mean values were observed in the AH26 group, the apical region and the Endofill group in the apical region, respectively. Post Hoc Tukey test revealed that there were no significant differences between different root canal regions in both cements (P>0.05.The region of root canal had no effect on the bond strength of cemented fiber posts to the root canal. Eugenol-based sealers (Endofill significantly reduced the bond strength between fiber posts luted with resin cement to the root canal.

  16. Evaluation of Chlorine Dioxide Irrigation Solution on the Microhardness and Surface Roughness of Root Canal Dentin.

    Science.gov (United States)

    Ballal, Nidambur Vasudev; Khandewal, Deepika; Karthikeyan, Saravana; Somayaji, Krishnaraj; Foschi, Federico

    2015-12-01

    The aim of this study was to evaluate the effect of chlorine dioxide and various other more common irrigation solutions on the microhardness and surface roughness of root canal dentin. Fifty human maxillary central incisors were sectioned longitudinally and treated for 1 minute with 5 ml of the following aqueous solutions (v/v%): Group 1: 13.8% chlorine dioxide, Group 2: 17% ethylene diamine tetraacetic acid (EDTA). Group 3: 7% maleic acid, Group 4: 2.5% sodium hypochlorite (5 ml/min), Group 5: Saline (control). Specimens were subjected to microhardness and surface roughness testing. Chlorine dioxide and sodium hypochlorite reduced the microhardness more than other test agents. The highest surface roughness was produced with maleic acid. Chlorine dioxide should be used cautiously during chemomechanical preparation of the root canal system in order to prevent untoward damage to the teeth. PMID:26767238

  17. The Influence of Dentine on the pH of Calcium Hydroxide, Chlorhexidine Gel, and Experimental Bioactive Glass-Based Root Canal Medicament

    OpenAIRE

    Ceci Nunes Carvalho; Laila Gonzales Freire; Alexandre Pinheiro Lima de Carvalho; Evandro Luiz Siqueira; José Bauer; Giovana Cunha Gritti; Juliana Pereira de Souza; Giulio Gavini

    2015-01-01

    Objectives. To evaluate the influence of dentine on the pH of different medications in standardized simulated canals. Materials and Methods. Forty resin blocks were divided into groups with and without dentine powder, as follows: 2% chlorhexidine gel; 2% chlorhexidine gel associated with calcium hydroxide PA; calcium hydroxide PA delivered in propylene glycol 600; and NPG delivered in distilled water. The dentine powder was obtained from the root dentine of bovine teeth and added to the medic...

  18. Dentinal crack formation during root canal preparations by the twisted file adaptive, Reciproc and WaveOne instruments

    OpenAIRE

    Gergi, Richard M.; Osta, Nada E.; Naaman, Alfred S.

    2015-01-01

    Objective: This study aimed to compare the frequency of dentinal microcracks after root canal shaping with 2 reciprocating (Reciproc and WaveOne) and 1 combined continuous reciprocating motion twisted files adaptive (TFA) rotary system. Materials and Methods: Ninety molars were chosen and divided into three groups of 30 each. Root canal preparation was achieved by using Reciproc R25, Primary WaveOne and TFA systems. All the roots were horizontally sectioned at 15, 9, and 3 mm from the apex. T...

  19. The Root Canal Biofilm

    NARCIS (Netherlands)

    Sluis, van der L.W.M.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, M.; Chávez de Paz, E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  20. Root canal irrigation

    NARCIS (Netherlands)

    L. van der Sluis; C. Boutsioukis; L.M. Jiang; R. Macedo; B. Verhaagen; M. Versluis

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  1. Comparative evaluation of demineralization of radicular dentin with 17% ethylenediaminetetraacetic acid, 10% citric acid, and MTAD at different time intervals: An in vitro study

    OpenAIRE

    Kumar, Yogender; Lohar, Jitendra; Bhat, Sureka; Bhati, Manisha; Gandhi, Aanesh; Mehta, Abhishek

    2016-01-01

    Background: The smear layer has the capability to protect the bacteria within the dentinal tubules from intracanal medicament. After removal of the smear layer from infected root canals, it allows disinfection of the entire root canal. The smear layer compromising the seal between the root canal sealer and root canal wall also decreases the penetration of irrigants into dentinal tubules. Aims: This study compares the amount of phosphorous liberated and demineralization of the radicular dentin...

  2. Scanning electron microscopy study of the adhesion of Prevotella nigrescens to the dentin of prepared root canals.

    Science.gov (United States)

    Yang, Sung-Eun; Bae, Kwang-Shik

    2002-06-01

    The purpose of this study was to evaluate the effect of the presence or absence of amorphous, irregular smear layers on the adhesion of Prevotella nigrescens, to the dentin of the root canal by using scanning electron microscopy (SEM). Human incisors extracted within 7 days, with no cavities, no fractures, and no evidence of calcification of the canal, were selected. After cutting the crown portion at the CEJ, root canal preparation was undertaken by using a modified crown-down technique with Profile and Gates Glidden drills. Ten milliliters of physiologic saline solution (groups 1 and 4), 10 ml of 3.5% NaOCl (groups 2 and 5), or 10 ml of NaOCl and 10 ml of 0.5 M EDTA (groups 3 and 6) were used as irrigation solution while preparing the canal. After vertical sectioning and ethylene oxide gas sterilization, samples (groups 1, 2, and 3) were immersed in brain-heart infusion broth with yeast extract, hemin, and menadione, inoculated with P. nigrescens (ATCC 33563), and incubated for 3 h at 37 degrees C. All samples were prepared for and observed with SEM. The data were analyzed by using t test and one-way ANOVA. Smear layer was observed to cover the entire root canal surface after root canal preparation. Smear layer was removed and the entrances of dentinal tubules opened widely after applying 3.5% NaOCl and 0.5 M EDTA. A significantly greater number of bacteria were found to adhere to those teeth in which a smear layer was present (p root canal preparation promoted adhesion and colonization of P. nigrescens to the dentin matrix, it might also increase the likelihood of canal reinfection. PMID:12067123

  3. Influence of irrigation sequence on the adhesion of root canal sealers to dentin: a fourier transform infrared spectroscopy and push-out bond strength analysis

    NARCIS (Netherlands)

    P. Neelakantan; S. Sharma; H. Shemesh; P.R. Wesselink

    2015-01-01

    Introduction There is a lack of evidence on the chemical interaction between sealers and dentin. The influence of irrigation on the chemical interaction between root canal sealers and dentin was analyzed by using Fourier transform infrared spectroscopy (FTIRS) and measurement of dislocation resistan

  4. Effect of the smear layer in the removal of calcium hydroxide from root canal walls

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    Hakan Arslan

    2012-01-01

    Full Text Available Background: The aim of this study was to investigate whether the smear layer influences the removal of calcium hydroxide from the root canal with manual or rotary instruments. Materials and Methods: The root canals of 48 freshly extracted single-rooted maxillary incisors were prepared to apical size 40 (n=40 and finally irrigated with sodium hypochlorite (group A, or ethylene diamine tetra acetic acid (EDTA followed by sodium hypo chlorite (group B. 20 teeth were assigned to each group, while the remaining eight teeth served as positive and negative controls. Each group was divided into two subgroups of 10 teeth (subgroup I - calcium hydroxide was removed with master apical file; subgroup II - with profile file; and, in all removal procedures, citric acid was used for irrigation. The percentage of calcium hydroxide-[Ca(OH [Ca(OH 2 ] coated surface area was calculated by image processing analysis. Results: Considering the root canal as a whole, the removal of Ca(OH 2 from the dentinal walls in group B showed significantly better results (P<0.05 as compared to group A. Conclusions: Under the conditions of this study, it can be concluded that the smear layer is important in the removal of calcium hydroxide.

  5. Bond strength and fracture analysis between resin cements and root canal dentin.

    Science.gov (United States)

    Lopes, Guilherme Carpena; Ballarin, Andressa; Baratieri, Luiz N

    2012-04-01

    The aim of this research is to evaluate bond strength between translucent fibre posts (White Post DC, FGM or FRC Postec Plus, Ivoclar/Vivadent) and intraradicular dentin at three different levels (cervical, middle and apical) using a dual-cure (AllCem, FGM) or self-curing (Multilink, Ivoclar/Vivadent) resin cement. Also, the fracture type after push-out test was analysed under SEM. Thirty-two extracted single-root teeth were selected. After undergoing endodontic therapy, they were randomly divided into four groups according to their post type and resin cement. Root canals were etched using 37% phosphoric acid, and Excite DSC adhesive (Ivoclar/Vivadent) was applied in all groups. The root was sectioned to obtain nine 1-mm-thick slices (three per third: coronal, middle, apical). All slices were subjected to push-out tests. Data were analysed using two-way anova. The mean bond strengths vary from 6.6 (4.6) MPa [apical] to 11.9 (5.9) MPa [cervical]. There were no significant differences between groups. Pearson χ(2)-test revealed significant differences in fracture types for all groups (P < 0.0001). The apical third had the lowest bond strengths and it was also shown to be the most critical region for luting fibre posts. PMID:22432821

  6. A Comparison of Push-Out Bond Strength of Two Endodontic Sealers to Root Canal Dentin: An in Vitro Study

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    Adl A

    2016-03-01

    Full Text Available Statement of Problem: Adhesion to root canal dentin is one of the necessary characteristics of endodontic sealers. MTA Fillapex (Angelus, Londria, PR, Brazil is one of the recently introduced MTA-based sealer. Only a limited number of studies have evaluated the bonding of this sealer to the dentin, with conflicting results. Objectives: The purpose of this study was to evaluate the bond strength of MTA Fillapex sealer to root canal dentin compared to an epoxy resinbased sealer (AH26 sealer. Materials and Methods: Twenty root blocks (6mm length were acquired from the middle part of the extracted single-rooted central or lateral maxillary incisor roots and their lumens were enlarged to achieve a diameter of 1.3 mm. MTA Fillapex and AH26 were placed in the lumens of root blocks (n = 10. The specimens were kept in an incubator for 7 days, the roots were sectioned perpendicular to their long axis to achieve slices with thickness of 1 mm and the push-out test was carried out by a universal testing machine. Results: The mean value of bond strength was 1.84 ± 0.7 Mpa for AH26 and 0.19 ± 0.1 Mpa for MTA Fillapex. The difference between the two groups was statistically significant (p < 0.001. Conclusions: With in the limitation of this study, AH 26 showed significantly higher bond strength in comparison to MTA Fillapex.

  7. The effect of three different antioxidants on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin: An in vitro study

    OpenAIRE

    Sarah Renjelina Christopher; Vijay Mathai; Rajesh Sasidharan Nair; Jeyabalaji Mano Christaine Angelo

    2016-01-01

    Objective: The effect of 10% ascorbic acid, 10% tannic acid, and 10% gallic acid on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin was evaluated. Materials and Methods: Fifty human premolars were decoronated to attain 14-mm root length and divided into five groups of 10 teeth each. Biomechanical preparation was done with rotary instruments. Group I specimens were irrigated with saline and 17% ethylenediaminetetraacetic acid (...

  8. Comparison of dentinal damage induced by different nickel-titanium rotary instruments during canal preparation: An in vitro study

    Directory of Open Access Journals (Sweden)

    Shiwani Garg

    2015-01-01

    Full Text Available Aim: To compare dentinal damage caused by hand and rotary nickel-titanium instruments using ProTaper, K3 Endo, and Easy RaCe systems after root canal preparation. Materials and Methods: One hundred and fifty freshly extracted mandibular premolars were randomly divided into five experimental groups of 30 teeth each and biomechanical preparation was done: Group 1 with unprepared teeth; Group 2 were prepared with hand files; Group 3 with ProTaper rotary instruments; Group 4 with K3 rotary; Group 5 with Easy RaCe rotary instruments. Then, roots were cut horizontally at 3, 6, and 9 mm from apex and were viewed under stereomicroscope. The presence of dentinal defects was noted. Statistical analysis: Groups were analyzed with the Chi-square test. Results: Significant difference was seen between groups. No defects were found in unprepared roots and those prepared with hand files. ProTaper, K3 rotary, and Easy RaCe preparations resulted in dentinal defects in 23.3%, 10%, and 16.7% of teeth, respectively. More defects were shown in coronal and middle sections, and no defect was seen in apical third. Conclusion: The present study revealed that use of rotary instruments could result in an increased chance for dentinal defects as compared to hand instrumentation.

  9. Effect of root canal rinsing protocol on dentin bond strength of two resin cements using three different method of test

    Science.gov (United States)

    Khoroushi, Maryam; Sheikhi, Mohammadreza; Soleimani, Bahram

    2016-01-01

    Background Different studies have used different tests to evaluate bond strength of resin cements to root dentin. In this in vitrostudy, three different tests were used to evaluate the bond strength of two resin cements to root dentin using two root dentin irrigation protocols. Material and Methods Ninety-six intact single-rooted teeth were selected for this study. Forty-eight teeth, with a root length of 15mm, were randomly divided into two groups and irrigated with normal saline or 2.5% sodium hypochlorite solutions during root canal preparation, respectively. For each 12 specimens from each group, fiber post #1 was bonded using an etch-and-rinse (Duo-Link) and a self-adhesive (BisCem) resin cement, respectively. After incubation, two specimens were prepared for the push-out test from the middle thirds of the roots. In another 24 teeth, after two 1.5-mm sections were prepared from the middle thirds of the prepared roots, sections of the post were bonded in two subgroups with each of the cements mentioned above and the samples were prepared for the pull-out test. For shear test, the crowns of 48 teeth were cut away, the dentin surfaces were prepared, the two irrigation solutions were used, and the resin cements were bonded. Data collected from the three tests were evaluated by ANOVA, post-hoc Tukey and Weibull tests (α=0.05). Results There were significant differences in the mean bond strength values between the three bond strength tests (P0.05). Conclusions Under the limitations of the present study, the method of the test used had an effect on the recorded bond strength between the resin cement and root dentin. Cement type and irrigation protocol resulted in similar variations with all the tests. Push-out and shear tests exhibited more coherent results. Key words:Bond strength, endodontically treated tooth, fiber post, resin cement, sodium hypochlorite. PMID:27398173

  10. Vitality of Enterococcus faecalis inside dentinal tubules after five root canal disinfection methods

    Directory of Open Access Journals (Sweden)

    Niranjan Ashok Vatkar

    2016-01-01

    Conclusion: E. faecalis has the ability to colonize inside dentinal tubules to a depth of >1000 μm. In contrast to conventional irrigants, both Nd: YAG and diode lasers were effective in eliminating the vitality of E. faecalis. NS, NaOCl, and CHX showed viable bacteria remaining in dentinal tubules.

  11. Effect of two types of FRC posts on the root canal wall retention

    Directory of Open Access Journals (Sweden)

    Arash Zar Bakhsh

    2016-07-01

    Full Text Available Background and Aims: The zirconia coated FRC posts (Ice light is the next generation of aesthetic posts , ice light features 70% fill of zirconia enriched, parallel glass fiber for exceptional strength. Its flexibility is close to dentine so stress is distributed. The aim of this study was to evaluate the effect of post type (FRC post and the zirconia coated FRC post on the retention to the root canal wall. Materials and Methods: 20 extracted human premolar teeth with 14 mm length were selected. After post space preparation, the teeth were randomly divided into two groups: Group1: the zirconia coated FRC post (Danville, USA Group2: FRC post (RTD DT light post, France. All posts were cemented with a dual-cure resin cement (Panavia, Kuraray, Japan. All specimens were mount in acrylic cylinders, and the push-out test was done using a universal testing machine (Instron 5500 R, USA at 1 mm/min speed. Data were analyzed using T-test. Results: The retentive strengths were in coronal (75.27+14.81 MPa, in middle (64.38+15.29 MPa and in apical (51.46+13.29 MPa for the zirconia coated FRC post, and also were in Coronal (59.16+1.91 MPa, in middle (66.83+12.32 MPa and in apical (67.88+17.47 MPa for the FRC post. There was no significant difference in mean retentive strength between two groups in each region (P=0.07. Conclusion: The FRC post and zirconia coated FRC post had similar retention to the root canal walls.

  12. Evaluation in vitro of effects of Er:YAG and Nd:YAG lasers irradiation on root canal wall, by stereoscopy, scanning electron micrography and thermographic camera

    International Nuclear Information System (INIS)

    This study was carried out to evaluate in vitro the effects of Nd:YAG laser and Er:YAG laser irradiation in the root canal wall by SEM, evaluating the apical leakage and the temperature changes during the laser irradiation. Seventy four extracted human teeth were used, they were instrumented and divided into seven groups of 10 teeth each. The teeth were evaluated through stereoscopy, by SEM, and with the thermographic camera. The Nd:YAG laser irradiation parameters were 100 mJ/p, 15 Hz, and Er:YAG laser were 160 mJ/p and 10 Hz, the irradiation was 4 times at 2 mm/sec speed, with 20 sec interval. The apical leakage was not observed in the teeth irradiated by Nd:YAG laser alone or in association with Er:YAG laser. However in the teeth irradiated only by the Er:YAG laser we observed a little leakage. By SEM observation the Nd:YAG laser irradiation showed melting and recrystallization in the dentin surface closing dentinal tubules, and in the samples irradiated by Er:Y AG laser a clean surface, opened dentinal tubules, and the combination by two lasers, showed melting covering some dentinal tubules The thermographic study found the temperature increase was not more than 6 deg C. This study showed the safety parameters applications of Er:YAG laser in association with Nd:YAG laser in root canal treatment, in order to not cause thermal damages to the periodontal tissues. (author)

  13. The ability of optical coherence tomography to characterize the root canal walls

    NARCIS (Netherlands)

    Shemesh, Hagay; Van Soest, Gijs; Wu, Min-Kai; Van der Sluis, Lucas W. M.; Wesselink, Paul R.

    2007-01-01

    A detailed understanding of the complexity of root canal systems is imperative to ensure successful root canal therapy. The aim of this study was to evaluate the ability of an optical coherence tomography (OCT) system in imaging root canal walls after endodontic preparation and to correlate these im

  14. Calcium loss from root canal dentin following EDTA and Tetracycline HCl Treatment with or without subsequent NaOCl irrigation and evaluation of microhardness of dentine

    Science.gov (United States)

    Mishra, Lora; Kumar, Manoj; Rao, C. V. Subba

    2012-07-01

    To assess Calcium loss from root canal dentin following EDTA and Tetracycline ñ HCL Treatment with or without subsequent NaOCl Irrigation and evaluation of microhardness of dentin. Materials and methods: Sixty freshly extracted single rooted premolars were selected.The teeth were sectioned l ongitudinally into two equal halves along the long axis using Diamond di sc. The one half of the specimen is used for the Calcium l oss eva luation by ICP-AES technique and the other one half with the acrylic block i s used for the micro hardness study. The data was analysed using One ñ way ANOVA and Post Hoc Tuckey test. Results: The maximum calcium loss was observed in Group V 17% EDTA +2.5% NaOCl (3.88 ± 0.30), followed by Group III 17% EDTA (3.46 ± 0.43 mg/L), Group VI 1% Tetracycline HCl + 2.5% NaOCl (1.71 ±0.28mg/L), Group IV Tetracycline HCl (1.46 ± 0.29mg/L). Group I distilled water (0.17± 0.25mg/L) and Group II 2.5% NaOCl (0.28± 0.05mg/L) had the least calcium loss value with p < 0.001. Dentin Microhardness i n Group I (67.6 ± 1.70 VHN), Group II (65.5 ± 3.57 VHN) Group IV and in Group VI ( 61.5± 1.09) showed significantly higher when compared to the mean values in Group III (59.7 ± 4.3 mg/L) and in Group V =(55.2±2.53VHN) withp<0.001. Conclusion: Group V 17% EDTA + 2.5% NaOCl resulted in maximum Calcium loss, but has reduced the microhardness. But Group VI 1%Tetracycline H Cl + 2.5% NaOCl solution e ffectively removed Calcium without much altering the microhardness of the r oot dentin .

  15. Frequency of second mesiobuccal canal in permanent maxillary first molars using the operating microscope and selective dentin removal: A clinical study

    Directory of Open Access Journals (Sweden)

    Suroopa Das

    2015-01-01

    Full Text Available Purpose: The aim of this study was to investigate whether the combination of operating microscope and selective dentin removal increased the frequency of second mesiobuccal (MB2 canal detection in permanent maxillary first molar teeth. Materials and Methods: One hundred fifty permanent maxillary first molars indicated for root canal treatment were randomly selected from patients belonging to the age group of 18-45 years irrespective of gender. After access cavity preparation and location of main canals, the MB2 canal orifice was sought in all teeth with an endodontic explorer under direct vision (Stage I, then under magnification with the aid of operating microscope (Stage II and finally with the combined use of operating microscope and selective dentin removal (Stage III. Results: MB2 canals were detected in 36%, 54% and 72% of the teeth in Stages I-III, respectively. Conclusion: This study demonstrated that dental operating microscope when used along with adjunctive aids such as selective dentin removal/troughing and good clinical knowledge will increase the ability of dental clinician to locate MB2 canals.

  16. Comparison of dentinal and apical crack formation caused by four different nickel-titanium rotary and reciprocating systems in large and small canals.

    Science.gov (United States)

    Zhou, Xin; Jiang, Shan; Wang, Xiao; Wang, Shuai; Zhu, Xiaofei; Zhang, Chengfei

    2015-01-01

    This study compared dentinal and apical crack formation after instrumentation with different nickel-titanium systems at two different working lengths (WL) in large and small canals. Two hundred and eighty human teeth were randomly distributed into two control and 12 experimental groups (n=20 each). Large and small canals were instrumented by the WaveOne, Protaper Universal System (PTU), Twisted File (TF), or Twisted File Adaptive (TFA) at 1 mm shorter than canal length (CL-1 mm) or 1 mm beyond apical foreman (CL+1 mm). Horizontal sections were microscopically observed to evaluate the dentinal cracks (only large canals). Scanning electron microscopy images were taken before and after instrumentation to assess apical cracks. All file types caused more apical cracks in small canals than in large canals regardless of the WL. During over-instrumentation (WL=CL+1 mm), the WaveOne and PTU groups developed significantly more dentinal cracks at the 6 and 9 mm sections than the TF and TFA groups.

  17. Effect of calcium hydroxide dressing on push-out bond strength of endodontic sealers to root canal dentin

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    Flávia Angélica Guiotti

    2014-01-01

    Full Text Available The aim of the present study was to evaluate the effect of calcium hydroxide dressing on the bond strength of three commercially available endodontic sealers (MTA Fillapex, Sealapex, and AH Plus to root canal dentin. Sixty slices of extracted human canines were obtained from cervical, middle, and apical root thirds. Root canals were standardized and specimens were filled and divided into six groups (n = 10: G1, MTA Fillapex; G2, Sealapex; and G3, AH Plus, with prior application of calcium hydroxide dressing; and G4, G5 and G6, without prior application of intracanal dressing. After 7 days, specimens were submitted to a push-out test. The data obtained were analyzed using the ANOVA and Tukey tests (a = 5%. Fracture modes were classified as adhesive, cohesive or mixed. The results of sealer bond strength to root canal dentin varied according to the sealer, root third and prior dressing application. Overall, calcium hydroxide dressing reduced bond strength in all root thirds, but the reduction was significant only for AH Plus, at the cervical (3.25 ± 1.69 and apical (4.43 ± 1.65 thirds (p 0.05. In conclusion, the calcium hydroxide dressing only had a negative effect on the bond strength of AH Plus, at the cervical and apical thirds. On the other hand, the bond strength values for MTA Fillapex and Sealapex were lower than those for AH Plus and, whereas the mixed failure mode predominated for AH Plus, the adhesive failure mode predominated for MTA Fillapex and Sealapex.

  18. The efficacy of ultrasonic irrigation to remove artificially placed dentine debris from human root canals prepared using instruments of varying taper

    NARCIS (Netherlands)

    van der Sluis, LWM; Wu, MK; Wesselink, PR

    2005-01-01

    Aim To investigate the influence of the taper of root canals on the effectiveness of ultrasonic irrigation to remove artificially placed dentine debris. Method Forty-four maxillary and mandibular canines were selected after bucco-lingual and mesio-distal radiographs indicated that their internal dia

  19. Push-out bond strength and dentinal tubule penetration of different root canal sealers used with coated core materials

    Science.gov (United States)

    Purali, Nuhan; Coşgun, Erdal; Calt, Semra

    2016-01-01

    Objectives The aim of this study was to compare the push-out bond strength and dentinal tubule penetration of root canal sealers used with coated core materials and conventional gutta-percha. Materials and Methods A total of 72 single-rooted human mandibular incisors were instrumented with NiTi rotary files with irrigation of 2.5% NaOCl. The smear layer was removed with 17% ethylenediaminetetraacetic acid (EDTA). Specimens were assigned into four groups according to the obturation system: Group 1, EndoRez (Ultradent Product Inc.); Group 2, Activ GP (Brasseler); Group 3, SmartSeal (DFRP Ltd. Villa Farm); Group 4, AH 26 (Dentsply de Trey)/gutta-percha (GP). For push-out bond strength measurement, two horizontal slices were obtained from each specimen (n = 20). To compare dentinal tubule penetration, remaining 32 roots assigned to 4 groups as above were obturated with 0.1% Rhodamine B labeled sealers. One horizontal slice was obtained from the middle third of each specimen (n = 8) and scanned under confocal laser scanning electron microscope. Tubule penetration area, depth, and percentage were measured. Kruskall-Wallis test was used for statistical analysis. Results EndoRez showed significantly lower push-out bond strength than the others (p < 0.05). No significant difference was found amongst the groups in terms of percentage of sealer penetration. SmartSeal showed the least penetration than the others (p < 0.05). Conclusions The bond strength and sealer penetration of resin-and glass ionomer-based sealers used with coated core was not superior to resin-based sealer used with conventional GP. Dentinal tubule penetration has limited effect on bond strength. The use of conventional GP with sealer seems to be sufficient in terms of push-out bond strength. PMID:27200279

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

    OpenAIRE

    Mitić Aleksandar; Mitić Nadica; Muratovska Ilijana; Stojanovska Vera; Popovska Lidija; Mitić Vladimir

    2008-01-01

    INTRODUCTION The basic work principle of all ultrasonic techniques is the piezoelectric effect of producing high frequency ultrasounds of small length, which are transmitted over the endodontic extensions or canal instruments into the root canal. When in contact with the tissue, ultrasonic vibrations are converted into mechanical oscillations. Ultrasonic waves and the obtained oscillations along with the synergic effect of irrigation bring about the elimination of smear layer from the root ca...

  1. Decalcifying capability of irrigating solutions on root canal dentin mineral content

    OpenAIRE

    Claudio Poggio; Alberto Dagna; Andrea Vinci; Riccardo Beltrami; Lucia Cucca; Luciano Giardino

    2015-01-01

    Background: Chelating agents are believed to aid root canal irrigation and to be able to remove the inorganic smear layer. Aims: The purpose of the present study was to evaluate and to compare the decalcifying capability of different irrigating solutions (Tubuliclean, Largal Ultra, ethylenediaminetetraacetic acid 17%, Tetraclean, Tetraclean NA). Materials and Methods: Sixty maxillary central incisors were used. Root canals were instrumented and irrigated. From each root, four comparable slice...

  2. Effect of Resin Cement Pre-heating on the Push-out Bond Strength of Fiber Post to Root Canal Dentin

    Science.gov (United States)

    Alizadeh Oskoee, Parnian; Nooroloyouni, Ahmad; Pornaghi Azar, Fatemeh; Sajjadi Oskoee, Jafar; Pirzadeh Ashraf, Ahmad

    2015-01-01

    Background and aims. Various factors influence the interfacial bond between the fiber posts and root canal dentin. The aim of the present study was to evaluate the effect of pre-warming of resin cement on the push-out bond strength of fiber posts to various segments of root canal dentin. Materials and methods. In this in vitro study, 40 single-rooted human premolars were decoronated and underwent root canal treatment along with post space preparation. The samples were randomly divided into two groups: In group 1, Panavia F 2.0 cement was used at room temperature; in group 2, the same cement was warmed to 55‒60°C before mixing. After fiber posts were placed and cemented in the root canals, 3 dentin/post sections (coronal, middle and apical) with a thickness of 3 mm were prepared. A universal testing machine was used to measure push-out bond strength in MPa. Data was analyzed using two-factor ANOVA and a post hoc Tukey test at α=0.05. Results. The mean value of push-out bond strength was high at room temperature, and the differences in the means of push-out bond strength values between the resin cement temperatures and between different root segments in each temperature were significant (Pcement up to 55-60°C reduced push-out bond strength to root canal dentin. In addition, in each temperature group bond strengths decreased from coronal to apical segments. PMID:26889360

  3. The effect of three different antioxidants on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin: An in vitro study

    Directory of Open Access Journals (Sweden)

    Sarah Renjelina Christopher

    2016-01-01

    Full Text Available Objective: The effect of 10% ascorbic acid, 10% tannic acid, and 10% gallic acid on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin was evaluated. Materials and Methods: Fifty human premolars were decoronated to attain 14-mm root length and divided into five groups of 10 teeth each. Biomechanical preparation was done with rotary instruments. Group I specimens were irrigated with saline and 17% ethylenediaminetetraacetic acid (EDTA. Specimens from groups II, III, IV, and V were irrigated with 5.25% sodium hypochlorite and 17% EDTA. Specimens from groups III, IV, and V underwent additional irrigation with antioxidants-10% ascorbic acid, 10% tannic acid, and 10% gallic acid, respectively. Following obturation with Resilon and Real Seal SE, scanning electron microscope (SEM analysis was done to note the maximum dentinal tubular penetration at the cervical, middle, and apical thirds of each specimen. The data were statistically analyzed using one-way analysis of variance (ANOVA, Post hoc and Dunnett′s test. Results: Maximum dentinal tubular penetration of Resilon and Real Seal SE was obtained following irrigation with 10% gallic acid. Conclusion: 10% gallic acid was superior among the antioxidant irrigants that enabled the increased dentinal tubular penetration of Resilon and Real Seal SE.

  4. Antimicrobial activity and substantivity of Uncaria tomentosa in infected root canal dentin

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    Daniel Rodrigo HERRERA

    2016-01-01

    Full Text Available Abstract The aim of this study was to analyze the antimicrobial activity and substantivity of Uncaria tomentosa Willd DC (cat’s claw, CC in root dentin contaminated with Enterococcus faecalis. Forty-eight human premolars were contaminated with E. faecalis (ATCC 29212 and randomly divided into four groups according to the irrigant used during chemomechanical preparation (CMP: CC group: 2% CC gel; CHX group: 2% chlorhexidine digluconate gel (CHX; NaOCl group: 5.25% sodium hypochlorite (NaOCl; and SS group: sterile saline (SS. Microbiological samples were collected before (S1 and after (S2 CMP and after 7 days (S3. Colony-forming units (CFU/mL at the different sampling times and comparisons among the groups were statistically analyzed by Wilcoxon and Kruskal-Wallis tests (p 0.05 in the CC and CHX groups. Bacterial load was higher in S3 than in S2 samples (p < 0.05 in the NaOCl and SS groups. Our results suggest antibacterial effect of 2% CC gel against E. faecalis in infected dentin, in addition to antibacterial substantivity of 2% CC and 2% CHX up to 7 days.

  5. Antimicrobial activity and substantivity of Uncaria tomentosa in infected root canal dentin.

    Science.gov (United States)

    Herrera, Daniel Rodrigo; Durand-Ramirez, Jorge Enrique; Falcão, Amanda; Silva, Emmanuel João Leal Nogueira da; Santos, Elizabete Brasil Dos; Gomes, Brenda Paula Figueiredo de Almeida

    2016-01-01

    The aim of this study was to analyze the antimicrobial activity and substantivity of Uncaria tomentosa Willd DC (cat's claw, CC) in root dentin contaminated with Enterococcus faecalis. Forty-eight human premolars were contaminated with E. faecalis (ATCC 29212) and randomly divided into four groups according to the irrigant used during chemomechanical preparation (CMP): CC group: 2% CC gel; CHX group: 2% chlorhexidine digluconate gel (CHX); NaOCl group: 5.25% sodium hypochlorite (NaOCl); and SS group: sterile saline (SS). Microbiological samples were collected before (S1) and after (S2) CMP and after 7 days (S3). Colony-forming units (CFU/mL) at the different sampling times and comparisons among the groups were statistically analyzed by Wilcoxon and Kruskal-Wallis tests (p 0.05) in the CC and CHX groups. Bacterial load was higher in S3 than in S2 samples (p < 0.05) in the NaOCl and SS groups. Our results suggest antibacterial effect of 2% CC gel against E. faecalis in infected dentin, in addition to antibacterial substantivity of 2% CC and 2% CHX up to 7 days.

  6. Antimicrobial activity and substantivity of Uncaria tomentosa in infected root canal dentin.

    Science.gov (United States)

    Herrera, Daniel Rodrigo; Durand-Ramirez, Jorge Enrique; Falcão, Amanda; Silva, Emmanuel João Leal Nogueira da; Santos, Elizabete Brasil Dos; Gomes, Brenda Paula Figueiredo de Almeida

    2016-01-01

    The aim of this study was to analyze the antimicrobial activity and substantivity of Uncaria tomentosa Willd DC (cat's claw, CC) in root dentin contaminated with Enterococcus faecalis. Forty-eight human premolars were contaminated with E. faecalis (ATCC 29212) and randomly divided into four groups according to the irrigant used during chemomechanical preparation (CMP): CC group: 2% CC gel; CHX group: 2% chlorhexidine digluconate gel (CHX); NaOCl group: 5.25% sodium hypochlorite (NaOCl); and SS group: sterile saline (SS). Microbiological samples were collected before (S1) and after (S2) CMP and after 7 days (S3). Colony-forming units (CFU/mL) at the different sampling times and comparisons among the groups were statistically analyzed by Wilcoxon and Kruskal-Wallis tests (p 0.05) in the CC and CHX groups. Bacterial load was higher in S3 than in S2 samples (p < 0.05) in the NaOCl and SS groups. Our results suggest antibacterial effect of 2% CC gel against E. faecalis in infected dentin, in addition to antibacterial substantivity of 2% CC and 2% CHX up to 7 days. PMID:27119588

  7. Reinforcement of thin-walled root canal structures for placement of esthetic dowels: a clinical report.

    Science.gov (United States)

    Ayad, Mohamed F; Bahannan, Salma A; Rosenstiel, Stephen F

    2011-01-01

    Thin-walled root canals always present a challenge to dentists to select a restorative treatment that does not further weaken the thin tooth structure. The prognosis of dowel and core restorations can be unpredictable. This clinical report describes the treatment of a patient with extensive caries extending into the root canal of an endodontically treated maxillary central incisor. The use of a flowable composite resin in combination with a quartz fiber reinforced post is described, resulting in the rehabilitation of a structurally compromised root canal with satisfactory esthetic and functional outcomes.

  8. Effect of the Type of Endodontic Sealer on the Bond Strength Between Fiber Post and Root Wall Dentin

    OpenAIRE

    Ramin Mosharraf; Sepideh Zare

    2014-01-01

    Objectives: An important factor that interferes with the bonding between the root canal wall and resin cement is the root canal sealer remnant. There is controversy about the effect of eugenol-containing sealers on the bond strength between resin cements and fiber post. The aim of this study was to evaluate the effect of the type of endodontic sealer on the bond strength of FRC posts cemented with resin cement to the root canal wall. Materials and Methods: In this in vitro study, 20 extracted...

  9. Evaluation in vitro of effects of Er:YAG and Nd:YAG lasers irradiation on root canal wall, by stereoscopy, scanning electron micrography and thermographic camera; Avaliacao in vitro dos efeitos da irradiacao laser de Er:YAG e Nd:YAG na parede dentinaria do canal radicular, sob observacao do estereoscopio, da micrografia eletronica e da camera termografica

    Energy Technology Data Exchange (ETDEWEB)

    Goya, Claudia

    2001-07-01

    This study was carried out to evaluate in vitro the effects of Nd:YAG laser and Er:YAG laser irradiation in the root canal wall by SEM, evaluating the apical leakage and the temperature changes during the laser irradiation. Seventy four extracted human teeth were used, they were instrumented and divided into seven groups of 10 teeth each. The teeth were evaluated through stereoscopy, by SEM, and with the thermographic camera. The Nd:YAG laser irradiation parameters were 100 mJ/p, 15 Hz, and Er:YAG laser were 160 mJ/p and 10 Hz, the irradiation was 4 times at 2 mm/sec speed, with 20 sec interval. The apical leakage was not observed in the teeth irradiated by Nd:YAG laser alone or in association with Er:YAG laser. However in the teeth irradiated only by the Er:YAG laser we observed a little leakage. By SEM observation the Nd:YAG laser irradiation showed melting and recrystallization in the dentin surface closing dentinal tubules, and in the samples irradiated by Er:Y AG laser a clean surface, opened dentinal tubules, and the combination by two lasers, showed melting covering some dentinal tubules The thermographic study found the temperature increase was not more than 6 deg C. This study showed the safety parameters applications of Er:YAG laser in association with Nd:YAG laser in root canal treatment, in order to not cause thermal damages to the periodontal tissues. (author)

  10. The ability of 5% Tamarindus indica extract as cleaner of the root canal wall smear layer

    Directory of Open Access Journals (Sweden)

    Erawati Wulandari

    2007-12-01

    Full Text Available Tamarindus indica is one of traditional medicines. Pulpa tamaridorum consist of organic acid that is usually used as irrigant and to remove root canal wall smear layer. The aimed of this study was to elucidate the ability of 5% Tamarindus indica extract as a root canal irrigant to remove root canal wall smear layer. Eighteen tooth samples were cut on cervical line and divided into 2 then groups were prepared with K file and irrigated. Group 1 was irrigated by sterile aquabidest and group 2 was irrigated by 5% Tamarindus indica extract. Samples were cut longitudinally and formed 7 × 2× 2 mm specimen. Each specimen was photographed by scanning electron microscope, scored and summed. The total score obtained is used as the hygiene value of root canal wall. The collected data were statistically analyzed by using independent t test at 0.05 level. The result of the study showed there was a significant difference between 5% Tamarindus indica extract and sterile aquabidest (p < 0.05, the hygiene value of 5% Tamarindus indica extract was higher than sterile aquabidest. The conclusion of this investigation showed that 5% Tamarindus indica extract remove root canal wall smear layer.

  11. Push-out bond strength of quartz fibre posts to root canal dentin using total-etch and self-adhesive resin cements

    OpenAIRE

    Kahnamouei, Mehdi A.; Mohammadi, Narmin; Navimipour, Elmira J.; Shakerifar, Maryam

    2011-01-01

    Objectives: Several adhesive systems are available for cementation of fibre posts into the root canal. The aim of the present study was to investigate the push-out bond strengths of quartz fibre posts to root dentin with the use of different total-etch and self-adhesive resin cements. Study Design: Ninety single-rooted human premolars were endodontically treated and standardized post-spaces were prepared. Fibre posts were cemented with different luting agents: total-etch (Nexus NX3, Duo-Link,...

  12. Evaluation of dentin cleansing by a detergent derived from castor oil (Ricinus communis) used as root canal irrigant: a scanning electron miscroscopy study

    OpenAIRE

    Letícia Molteni Aguiar; Lilian Eiko Maekawa; Adriana Chung; Maria Renata Giazzi Nassri

    2010-01-01

    Introduction and objective: To evaluate, by scanning electron microscopy (SEM), the cleaning of root canal walls after biomechanical preparation and irrigation with castor oil (Endoquil®) and 0.5% sodium hypochlorite (NaOCl). Material and methods: Fifteen maxillary incisors were subjected to standardized root canal instrumentation with different irrigants (n = 5): G1 – Endoquil; G2 – 0.5% NaOCl; G3 – saline solution (control). After instrumentation, the teeth were prepared for SEM analysis (...

  13. Groin pain associated with ultrasound finding of inguinal canal posterior wall deficiency in Australian Rules footballers

    OpenAIRE

    Orchard, J. W.; Read, J. W.; Neophyton, J.; Garlick, D

    1998-01-01

    OBJECTIVES: To investigate the prevalence of inguinal canal posterior wall deficiency (sports hernia) in professional Australian Rules footballers using an ultrasound technique and correlate the results with the clinical symptom of groin pain. METHODS: Thirty five professional Australian footballers with and without groin pain were investigated blind with a dynamic high resolution ultrasound technique for presence of posterior wall deficiency. RESULTS: Fourteen players had a history of ...

  14. Adaptation of threaded dowels to dentin.

    Science.gov (United States)

    Zmener, O

    1980-05-01

    Adaptation of threaded dowels to the walls of the canals is minimal in the cervical third and maximal in the apical third. Each of the three types of dowels may cause lateral stresses and possibly fracture. Matched reamers and dowels reduce the danger of fracture. Smaller-diameter dowels maintain less contact with the dentin and avoid weakening the root. The Kurer Anchor system provided a satisfactory combination of nonlateral residual stresses which protected the root from complications. PMID:6988582

  15. Effect of root canal rinsing protocol on dentin bond strength of two resin cements using three different method of test

    OpenAIRE

    Khoroushi, Maryam; Sheikhi, Mohammadreza; Khalilian-Gourtani, Amirhossein; Soleimani, Bahram

    2016-01-01

    Background Different studies have used different tests to evaluate bond strength of resin cements to root dentin. In this in vitrostudy, three different tests were used to evaluate the bond strength of two resin cements to root dentin using two root dentin irrigation protocols. Material and Methods Ninety-six intact single-rooted teeth were selected for this study. Forty-eight teeth, with a root length of 15mm, were randomly divided into two groups and irrigated with normal saline or 2.5% sod...

  16. Defective anterior wall of inguinal canal and its role in the pathophysiology of direct inguinal hernias

    Directory of Open Access Journals (Sweden)

    Abdolvahabi SA

    2002-06-01

    Full Text Available Regrding pathophysiology of direct inguinal hernias the following are pointed our:1-Absence of contribution of fascia of transverses abdominis muscle along with fascia transversalis in making posterior wall of the inguinal canal causing defect point in Hesselbachs triangle.2- Defects in protectin mechanisms of the inguinal canal such as: I shutter like effect of the arch of internal oblique and transverses abdominis muscles. ii Sphincter like effect of fascia of oblique muscle (anterior wall of canl.During several years of observation and practice in the field of surgical repair of hernias, a new phenomenon was observed regarding the etiology of direct hernias.Evaluation of superficial ring and Ant. Wall of inguinal canal in 25 patients showed that the ant. Wall was not perfect and the defect was seen as a spectrum of moderate defect to complete absence of the wall. This phenomenon may be a newly observed mechanism in pathology of direct inguinal hernia that might help the operative repair. Taking this into account, i.e. repair of this defect, might help the classic herniorrhaphy techniques

  17. Techniques of the tympanomastoidectomy with reconstruction of the posterior bone wall of the external auditory canal

    Directory of Open Access Journals (Sweden)

    Dankuc Dragan

    2015-01-01

    Full Text Available A combined tympanoplasty method, the mobile-bridge tympanoplasty, has been applied at the Clinic for Ear, Nose and Throat Diseases in Novi Sad since 1998. Mobile-bridge tympanoplasty is performed at our Clinic by applying Feldmann’s procedure utilizing a microsurgical oscillating saw. It is a combination of closed and open techniques for surgical treatment of middle ear diseases. In addition to this technique, a method for reconstruction of the posterior bone wall of the external auditory canal was introduced. This procedure is applied in cases of damage or impairment of the bony ear canal wall using mastoid cortical temporal bone graft or modeled cartilage of the concha. Maintenance of general anatomical relations in the middle ear enables good ventilation of pneumatic spaces of the middle ear and Eustachian tube permeability, thus providing good conditions for ossicular chain reconstruction. The incidence of recurrent cholesteatoma in combined mobile-bridge tympanoplasty and tympanoplasty with reconstruction of the posterior bone wall was 6% in total. The incidence values for the recurrent cholesteatoma in closed tympanoplasty and in cases of open techniques were 10%. Mobile-bridge tympanoplasty and reconstruction of the posterior bone wall of external auditory canal are methods of choice in surgical treatment of middle ear cholesteatoma that progressed to the attic space, sinus tympani and facial recess.

  18. Analysis of sealing ability of root canal sealers using scanning electronic microscopy technique

    Directory of Open Access Journals (Sweden)

    Vujašković Mirjana

    2010-01-01

    Full Text Available Introduction. An ideal endodontic sealer should adhere firmly both to dentin and to gutta-percha. Objective. The aim of this study was to evaluate the adhesion of the root canal filling to dentin and gutta-percha using scanning electronic microscopy (SEM. Methods. The sealing ability of endodontic sealers to dentinal walls of the root canal was assessed in recently extracted human single canal premolars. Twenty teeth were prepared using the crown-down technique and irrigated with 3% NaOCl. A total of 20 samples were divided into two groups. The root canals were obturated using Ketac-Endo Aplicap and GutaFlow. The sealing ability and adhesion properties at the sealer-dentin interface were studied using SEM and the results were rated from 1 to 3; extremely good adhesion (rated 1, good adhesion (rated 2 and a relatively good adhesion (rated 3. Results. The results showed extremely good adhesion on Ketac-Endo and GuttaFlow dentin interface. GuttaFlow has strong adhesion (rated 1 to gutta-percha in comparison with Ketac-Endo to gutta-percha interface (rated 2. Conclusion. New GuttaFlow filling material has a strong sealing ability and excellent adhesion to dentinal walls and gutta-percha cones. Ketac-Endo showed excellent bond to dentin with a slightly weaker adhesion capacity to the gutta-percha cones in comparison to GuttaFlow.

  19. [The use of ultrasonic files in canal preparation].

    Science.gov (United States)

    Calas, P; Terrie, B

    1990-01-01

    The continuous high volume of irrigating solution delivered by the ultrasonic system facilitates the root canal debridement. An excellent cleaning of dentin wall is obtained even on surfaces unreached by the mechanical instrumentation. In order to obtain an efficacious preparation, the use of ultrasonic files were combined with instrumentation. This new technique is described in this article. PMID:2168733

  20. [The use of ultrasonic files in canal preparation].

    Science.gov (United States)

    Calas, P; Terrie, B

    1990-01-01

    The continuous high volume of irrigating solution delivered by the ultrasonic system facilitates the root canal debridement. An excellent cleaning of dentin wall is obtained even on surfaces unreached by the mechanical instrumentation. In order to obtain an efficacious preparation, the use of ultrasonic files were combined with instrumentation. This new technique is described in this article.

  1. The influence of the Q-switched and free-running Er:YAG laser beam characteristics on the ablation of root canal dentine

    International Nuclear Information System (INIS)

    Laser based dental treatment is attractive to many researchers. Lasers in the 3 μm region, as the Er:YAG, are suitable especially for endodontic applications. In this study a pulsed free-running and Q-switched laser was used for the ablation experiments of root canal dentine. The laser beam was either directly focused on the dental tissue or delivered to it through an infrared fiber. For different spatial beam distributions, energies, number of pulses and both laser operations the quality characteristics (crater's shape formation, ablation efficiency and surface characteristics modification) were evaluated using scanning electron microscopy (SEM). The craters produced, generally, reflect the relevant beam profile. Inhomogeneous spatial beam profiles and short pulse duration result in cracks formation and lower tissue removal efficiency, while longer pulse durations cause hard dentine fusion. Any beam profile modification, due to laser characteristics variations and the specific delivering system properties, is directly reflected in the ablation crater shape and the tissue removal efficiency. Therefore, the laser parameters, as fluence, pulse repetition rate and number of pulses, have to be carefully adjusted in relation to the desirable result

  2. The influence of the Q-switched and free-running Er:YAG laser beam characteristics on the ablation of root canal dentine

    Energy Technology Data Exchange (ETDEWEB)

    Papagiakoumou, Eirini; Papadopoulos, Dimitrios N.; Khabbaz, Marouan G.; Makropoulou, Mersini I.; Serafetinides, Alexander A

    2004-06-30

    Laser based dental treatment is attractive to many researchers. Lasers in the 3 {mu}m region, as the Er:YAG, are suitable especially for endodontic applications. In this study a pulsed free-running and Q-switched laser was used for the ablation experiments of root canal dentine. The laser beam was either directly focused on the dental tissue or delivered to it through an infrared fiber. For different spatial beam distributions, energies, number of pulses and both laser operations the quality characteristics (crater's shape formation, ablation efficiency and surface characteristics modification) were evaluated using scanning electron microscopy (SEM). The craters produced, generally, reflect the relevant beam profile. Inhomogeneous spatial beam profiles and short pulse duration result in cracks formation and lower tissue removal efficiency, while longer pulse durations cause hard dentine fusion. Any beam profile modification, due to laser characteristics variations and the specific delivering system properties, is directly reflected in the ablation crater shape and the tissue removal efficiency. Therefore, the laser parameters, as fluence, pulse repetition rate and number of pulses, have to be carefully adjusted in relation to the desirable result.

  3. Comparative evaluation of canal transportation, centering ability, and remaining dentin thickness between WaveOne and ProTaper rotary by using cone beam computed tomography: An in vitro study

    Science.gov (United States)

    Jain, Aditi; Asrani, Hemant; Singhal, Abhinav Chand; Bhatia, Taranjeet Kaur; Sharma, Vaibhav; Jaiswal, Pragya

    2016-01-01

    Aims: To compare the canal transportation, centering ability, and remaining dentin thickness of WaveOne and ProTaper systems using cone beam computed tomography. Subjects and Methods: Forty extracted human single-rooted premolars were used in the present study. Preinstrumentation scanning of all teeth was taken; canal curvatures were calculated, and the samples were randomly divided into two groups, with twenty samples in each group; one group was instrumented with WaveOne system and the other group with ProTaper rotary system. Postinstrumentation scans were performed, and the two scans were compared to determine canal transportation, centering ability, and remaining dentin thickness at 3 mm, 6 mm, and 9 mm from the root apex. Statistical Analysis Used: Student's unpaired t-test. Results: Using Student's unpaired t-test, results were as follows: for canal transportation, Group 1 showed significant difference at 3 mm and 6 mm and insignificant difference at 9 mm while Group 2 showed insignificant difference in all the three regions. For centering ability and remaining dentin thickness, Group 1 showed insignificant difference at 3 mm and 9 mm while significant difference at 6 mm was obtained. When comparison of remaining dentin thickness was done at three levels using two groups WaveOne and ProTaper, there was no significant difference between two groups. Conclusions: (1) WaveOne single reciprocation file system respected better canal anatomy better than ProTaper. (2) Individually, centering ability of WaveOne was better at 3 mm, 6 mm, and 9 mm levels. (3) However, ProTaper individually was better centered at 3 mm (apical third) and 9 mm (coronal 3rd) levels than 6 mm level (middle third). PMID:27656063

  4. Dentin ablation-rate measurements in endodontics witj HF and CO2 laser radiation

    Science.gov (United States)

    Makropoulou, Mersini I.; Serafetinides, Alexander A.; Khabbaz, Marouan; Sykaras, Sotirios; Tsikrikas, G. N.

    1996-01-01

    Recent studies focused on the ability of the laser light to enlarge the root canal during the endodontic therapy. The aim of this research is the experimental and theoretical study of the ablation rate of two infrared laser wavelengths on dentin. Thirty freshly extracted human teeth were longitudinally sectioned at thicknesses ranged from 0.5 to 2 mm, and irradiated on the root canal dentin. The measured ablation rates in dentinal wall of the root canal showed that the HF laser at 2.9 micrometer can more effectively penetrate into the tissue, whereas the carbon dioxide laser at 10.6 micrometer leads to high thermal damage of the ablation crater surroundings.

  5. Comparison of canal wall incisions for tympanoplasty for large central perforations

    Directory of Open Access Journals (Sweden)

    Sohil I Vadiya

    2015-01-01

    Full Text Available Aim and Objective: To compare surgical outcomes with different canal wall incisions used in common practice for tympanoplasty for large perforations. Materials and Methods: Totally 88 patients included in the study and three groups formed. Group A consisted of 35 patients and the vascular strip incision with anterior tucking (VSAT technique used in these patients. Group B consisted of 31 patients and the tympanometal flap with anterior tucking (TMFAT technique used in these patients. Group C had 22 patients and the near full cuff (NFC technique used in them. Results: Success rate of 97.15% observed for Group A, 93.55% observed for Group B and 86.36% observed for Group C patients. Most of the patients in Group A had healing time <4 weeks, whereas most patients in Group C had more than 5 weeks of healing time. Granulations were not seen in Group A, whereas 3 among Group B and 4 among Group C patients developed granulations. Canal wall sagging was seen in 1 among Group A, 2 among Group B and 4 among Group C patients. The average hearing gain in terms of improvement in air-bone gap for Groups A, B and C have been 19.62, 19.25 and 17.35 db, respectively. Conclusion: The VSAT is the method of choice in terms of better success rates and minimum canal skin related complications in postoperative period. The VSAT also provides good exposure during surgery. Hearing gain in Group A is significantly better than Group C (P = 0.023.

  6. Photo elastic analysis of stresses in the root canal walls around double taper and

    Directory of Open Access Journals (Sweden)

    Zafar Mahdavi Ezadi

    2013-10-01

    Full Text Available   Background and Aims : According to the common application of non-metal prefabricated posts in dentistry and lack of enough information about the stress distribution in the root canal walls by these posts, this study was performed to compare the effect of two simple taper and double taper posts on the stress distribution on root canal walls by photo elastic method .   Materials and Methods: The design of this study was experimental in photoelastic system. The posts, used in this investigation, were double taper and simple taper fiber posts with 0.9 mm diameter and 20 mm length and epoxy resin. First two photo elastic models with tooth dimensions were fabricated and the posts were placed inside the model. Then the core of the each post was fabricated on the model. Each models were loaded in polariscope and the formed fringe order colored ring were photographed.   Results: In 100 N, 90 degree angle loading in cervical and apical fringe order showed 2.50 and 1.39 in simple taper posts and 1.39 and 2.35 in double taper post. In 150 N, 30 degree angle loading in cervical and apical fringe order showed 4 and 2.65 in simple taper posts, and 4 and 2.5 in double taper post.   Conclusion: In the vertical and oblique loads, double taper fiber post showed better stress distribution than that of simple tapered posts.

  7. En face optical coherence tomography investigation of interface fiber posts/adhesive cement/root canal wall

    Science.gov (United States)

    Negruţiu, Meda; Sinescu, Cosmin; Topala, Florin; Rominu, Mihai; Markovic, Dubravka; Pop, Daniela; Hughes, Michael; Bradu, Adrian; Dobre, George; Podoleanu, Adrian G.

    2009-07-01

    This study analyzes the adaptation and gap width between fiber posts, adhesive luting cement and root canal wall using optical coherence tomography. The results prove the importance of assessing the quality of the interface after each process of fiber post luting.

  8. Effect of light-curing units on push-out fiber post bond strength in root canal dentin

    Science.gov (United States)

    Calixto, L. R.; Bandéca, M. C.; Silva, F. B.; Rastelli, A. N. S.; Porto-Neto, S. T.; Andrade, M. F.

    2009-08-01

    The purpose of this study was to evaluate the effectiveness of different light-curing units on the bond strength (push-out) of glass fiber posts in the different thirds of the root (cervical, middle and apical) with different adhesive luting resin systems (dual-cure total-etch; dual-cured and self-etch bonding system; and dual-cure self-adhesive cements), Disks of the samples ( n = 144) were used, with approximately 1 mm of thickness of 48 bovine roots restored with glass fiber posts, that were luted with resin cements photo-activated by halogen LCU (QTH, Optilux 501) and blue LED (Ultraled), with power densities of 600 and 550 mW/cm2, respectively. A universal testing machine (MTS 810 Material Test System) was used with a 1 mm diameter steel rod at cross-head speed of 0.5 mm/min until post extrusion, with load cell of 50 kg, for evaluation of the push-out strength in the different thirds of each sample. The push-out strength values in kgf were converted to MPa and analyzed through Analysis of Variance and Tukey’s test, at significance level of 5%. The results showed that there were no statistical differences between the QTH and LED LCUs. The self-adhesive resin cement had lower values of retention. The total-etch and self-adhesive system resin cements seem to be a possible alternative for glass fiber posts cementation into the radicular canal and the LED LCU can be applied as an alternative to halogen light on photo-activation of dual-cured resin cements.

  9. Comparison of Push-out Bond Strength of Gutta-percha to Root Canal Dentin in Single-cone and Cold Lateral Compaction Techniques with AH Plus Sealer in Mandibular Premolars.

    Science.gov (United States)

    Mokhtari, Hadi; Rahimi, Saeed; Forough Reyhani, Mohammad; Galledar, Saeedeh; Mokhtari Zonouzi, Hamid Reza

    2015-01-01

    Background and aims. The single-cone technique has gained some popularity in some European countries. The aim of the present study was to compare the push-out bond strength of gutta-percha to root canal dentin with the single-cone and cold lateral compaction canal obturation techniques. Materials and methods . The root canals of 58 human mandibular premolars were prepared using modified crown-down technique with ProTaper rotary files up to #F3as a master apical file (MAF) and divided randomly into groups A and B based on canal obturation technique. In group A (n = 29) the root canals were obturated with single-cone technique with #F3(30/.09) ProTaper gutta-percha, which was matched with MAF in relation to diameter, taper and manufacturer; in group B (n = 29) the canals were obturated with gutta-percha using cold lateral compaction technique. In both groups AH plus sealer were used. After two weeks of incubation, three 2-mm slices were prepared at a distance of 2 mm from the coronal surface and push-out test was carried out. Data were analyzed with descriptive statistics using independent samples t-test. Results. There were statistically significant differences between two groups. The mean push-out bond strength was higher in group B (lateral compaction technique) compared to group A (single-cone technique; P < 0.05). Conclusion . Use of single-cone technique for obturation of root canals resulted in a lower bond strength compared to cold lateral compaction technique. PMID:26889358

  10. Clinical application of canal wall reconstruction with homograft cortical bone plate in canal wall down tympanoplasty%自体皮质骨外耳道重建在开放式鼓室成形术中的应用

    Institute of Scientific and Technical Information of China (English)

    马喆; 习国平; 张社江; 蔡爱军; 郝艳芳; 梁宝莲

    2012-01-01

    目的 对开放式鼓室成形术中利用自体皮质骨行外耳道重建的方法及疗效进行评价.方法 将接受手术治疗的胆脂瘤型中耳炎患者49例(49耳)分为两组.实验组,行开放式鼓室成形术+自体皮质骨外耳道重建术25例(耳);对照组,行常规开放式鼓室成形术+耳甲腔成形术24例(耳).术后随访6 ~ 36个月,观察两组患者术后听力结果、干耳率情况.结果 以术后语言频率气骨导差缩小>15 dB或气导听阈<40 dB为有效标准,实验组有效率68% (17/25),对照组有效率62.5% (15/24),组间比较无统计学意义(x2=0.1635,P>0.05).实验组干耳率为92.5%(23/25),明显高于对照组58.33%(14/24),差异有统计学意义(x2=4.363 6,P <0.05).实验组重建后的外耳道结构正常,无闭锁或狭窄情况发生.中耳乳突腔均接近正常.全部病例均无胆脂瘤复发.结论 开放式鼓室成形术加自体皮质骨外耳道重建术,能有效清除中耳病灶组织、恢复外耳道和中耳的结构,术后听力结果满意,干耳率高,是较为理想的手术方式.%Objective To evaluate the therapy of canal wall down tympanoplasty and canal reconstruction with homo-graft cortical bone plate. Methods Retrospective case review. 49 patients were divided into 2 groups. The experimental group that included 25 ears underwent canal wall down tympanoplasty and canal reconstruction with homograft cortical bone plate, while the control group that included 24 ears underwent regular canal wall down tympanoplasty with canal reconstruction. Follow up lasted 6-36 months and postoperative hearing and dry ear rate were evaluated. Results The criteria for success were defined as AB gap closure over 15 dB HL or air conduction threshold less than 40 dB HL (using the mean of 0. 5-, 1-, and 2-KHz threshold values). The experimental group's effective rate was 68% (17/25) and the control group's was 62. 5% (15/24). No significant difference was found between the

  11. Filling in dentinal tubules

    International Nuclear Information System (INIS)

    We report on the demonstration of two occlusion protocols for exposed dentinal tubules with the aid of gold nanoparticles: first, the inner tubular walls are pre-adsorbed by sub-monolayer gold nanoparticles, followed by a silver staining process to achieve tubular occlusion. Second, highly concentrated gold nanoparticles were brushed into the exposed ends of dentinal tubules, followed by laser irradiation which promoted sintering of gold nanoparticle aggregates via photothermal conversion

  12. Evolution of root canal sealers: An insight story

    Directory of Open Access Journals (Sweden)

    Sanjeev Tyagi

    2013-01-01

    Full Text Available Attainment of ideal root canal treatment comprises various essential factors such as proper instrumentation, biomechanical preparation, obturation, and ultimately depending upon the case, post-endodontic restoration. Main objective of the treatment is to get absolute rid of microbial entity and prevent any future predilection of re-infection. In order to achieve that, proper seal is required to cut down any chance of proliferation of bacteria and future occurrence of any pathology. Although gutta-percha has been the standard obturating material used in root canal treatment, it does not reinforce endodontically treated roots owing to its inability to achieve an impervious seal along the dentinal walls of the root canal. Gutta-percha does not from a monoblock even with the use of a resin-based sealer such as AH Plus because the sealer does not bind to gutta-percha. As a result, a monoblock is formed (consisting of Resilon core material, Resin sealer, bonding agent/primer, and dentin. Another reason of Resilon being a better obturating material could be that the removal of smear layer by ethylenediaminetetraacetic acid (EDTA after biomechanical preparation may have allowed the root canal filling material and root canal sealers to contact the canal wall and penetrate in the dentinal tubules, which may increase the strength of roots. New silicone-based sealers like Roekoseal automix and the most recent GuttaFlow have some affirmative results regarding solubility and biocompatibility, as compared to other sealers. Methacrylate resin-based sealers and mineral trioxide aggregate (MTA-based sealers have opened a new horizon for sealers.

  13. Root canal therapy and microcracks of the root canal wall%根管治疗与根管壁微裂

    Institute of Scientific and Technical Information of China (English)

    赵朋朋; 秦宗长

    2014-01-01

    根管治疗是治疗牙髓病和根尖周病的首选方法。研究表明:根管治疗的多个环节都会产生根管壁的微裂,微裂在咀嚼负荷等因素作用下可能进展成为根折,降低患牙的远期生存率。本文将就根管治疗与根管壁微裂间的研究进展作一综述。%Root canal therapy is the most popular treatment for pulpitis and apical periodontitis. Previous research showed that endodontic procedures might contribute to incomplete cracks in the root dentine. These localized defects may develop into fractures under masticatory pressure and reduce the long-term survival of the tooth. This review focuses on the relationship between root canal therapy and microcracks at the root canal wall.

  14. 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.

  15. Bond strength of fibre glass and carbon fibre posts to the root canal walls using different resin cements.

    Science.gov (United States)

    Farina, Ana Paula; Cecchin, Doglas; Garcia, Lucas da Fonseca Roberti; Naves, Lucas Zago; Pires-de-Souza, Fernanda de Carvalho Panzeri

    2011-08-01

    The aim of the study was to evaluate the bond strength of fibre glass and carbon fibre posts in the root canal walls cemented with self-adhesive (RelyX-Unicem) and chemical (Cement-Post) resin cements. Forty maxillary canines were divided into four groups according to the cement and post used and submitted to the push-out test (0.5 mm min(-1)). The data were submitted to statistical analysis (2-way ANOVA, Bonferroni--PFibre glass presented the best results when cemented with RelyX-Unicem and Cement-Post (Pfibre glass posts and RelyX-Unicem.

  16. Ancient engineering geology projects in China; A canal system in Ganzu province and trenches along the Great Wall in Ningxia Hui Autonomous Region

    Science.gov (United States)

    Wallace, R.E.; Bucknam, R.C.; Hanks, T.C.

    1994-01-01

    Two major construction projects of ancient times in China involved what today would be considered engineering geology. We describe an ancient canal system in Gaotai County, Gansu province that was possibly begun in the Han dynasty (206 BC-220 AD). The canal system heads at the Dasha River and extends northwestward for about 55 km to the City of Camels and Xusanwan village. Four parallel canals are present at the local site we examined. The canals were likely built primarily to transport water but may also have served as defensive military barriers. A second project involves trenches and berms along the north side of the Great Wall, clearly part of the Great Wall defensive system. This site is in Ningxia Autonomous Region near the town of Shizuishan. ?? 1994.

  17. Diode laser irradiation effects on the sealing ability of root canal sealers

    Science.gov (United States)

    Ribeiro, A. C.; Nogueira, G. E. C.; Mayer, M. P. A.; Antoniazzi, J. H.; Zezell, D. M.

    2010-06-01

    This study aimed to test the hypothesis that dentine alterations induced by 810 nm-diode laser may affect the interaction between root canal sealers and the dentin wall. Seventy-two single root human teeth were selected and root canals were enlarged with K-files. Dentine was treated with 0.5% NaOCl and 17% EDTA-T and irradiated (laser group) by diode laser (810 nm/ P = 2.5W/ I = 1989 W/cm2) or remained non-irradiated (control group). Six samples per group were analyzed by scanning electron microscopy (SEM). The remaining samples of each group were divided into three subgroups ( n = 10) and sealed with one of the tested sealers (N-Rickert/AHPlus™/Apexit®). Apical leakage was estimated by evaluating penetration of 0.5% methylene-blue dye. SEM analysis revealed that dentine at the apical third in irradiated samples was melted and fusioned whereas non-irradiated samples exhibited opened dentinal tubules. Despite the morphological changes induced by irradiation, laser did not affect the sealing ability of N-Rickert and AHPlusTM sealers. However, the length of apical leakage in roots filled with Apexit® was lower in irradiated root canals than in non-irradiated samples ( p root canal walls promoted by diode laser irradiation may improve de sealing ability of Apexit®, a calcium hydroxide-based sealer, suggesting that improved sealing promoted by irradiation may represent an additional factor contributing to the endodontic clinical outcome.

  18. 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.

  19. Comparison of the effectiveness of 3 irrigation devices for the cleaning of root canal walls instrumented with oscillatory and rotary techniques.

    Science.gov (United States)

    Ferreira, Nadia Souza; Camargo, Carlos Henrique Ribeiro; Palo, Renato Miotto; Martinho, Frederico Canato; Gomes, Ana Paula Martins

    2015-01-01

    In this study, scanning electron microscopy (SEM) was used to evaluate the smear layer removal of 3 irrigation devices. The study hypothesis was that more contemporary side-vented needles and brush-covered needles are more efficient for smear layer removal of root canals than traditional needles. The aim of this study was to compare the effectiveness of these irrigation devices in the cleansing of root canals instrumented with oscillatory and rotary systems. Sixty single-rooted teeth were divided according to instrumentation and irrigation techniques into 6 groups. The teeth were prepared for SEM analysis to evaluate the cleansing of cervical, middle, and apical thirds. For all groups, the cleansing of the cervical and middle thirds was better than that of the apical third (P cleansing of root canal walls (P > 0.05). PMID:25734291

  20. Root dentine and endodontic instrumentation: cutting edge microscopic imaging.

    Science.gov (United States)

    Atmeh, Amre R; Watson, Timothy F

    2016-06-01

    Cutting of the dental hard tissues is an integral part of restorative dentistry. Cutting of the root dentine is also needed in preparation prior to endodontic treatment, with significant commercial investment for the development of flexible cutting instruments based around nickel titanium (NiTi) alloys. This paper describes the evolution of endodontic cutting instruments, both in materials used, e.g. the transition from stainless steel to NiTi, and the design of the actual instruments themselves and their method of activation-by hand or motor driven. We have been examining tooth-cutting interactions microscopically for over 25 years using a variety of microscopic techniques; in particular, video-rate confocal microscopy. This has given a unique insight into how many of the procedures that we take for granted are achieved in clinical practice, by showing microscopic video images of the cutting as it occurs within the tooth. This technology has now been extended to allow imaging of the endodontic instrument and the root canal wall for the first time. We are able to image dentine distortion and crack propagation during endodontic filing of the root canal space. We are also able to visualize the often claimed, but seldom seen action of contemporary endodontic instruments. PMID:27274802

  1. 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.

  2. A comparative study of intra canal stress pattern in endodontically treated teeth with average sized canal diameter and reinforced wide canals with three different post systems using finite element analysis

    Directory of Open Access Journals (Sweden)

    Kaur Amandeep

    2010-01-01

    Full Text Available Study methodology: This is a comparative study of intra canal stress patterns in endodontically treated maxillary central incisor with: average sized canal diameter and wide canals reinforced with three different post systems - cast post and core, carbon fiber post, stainless steel post; restored with ceramic crown using finite element analysis (FEA. All the models were subjected to a force of 100N applied at 450 to the long axis of the tooth at the middle third of the palatal surface of the restored ceramic crown. Results: The FEA revealed that all the post systems showed maximum stress in the coronal and middle third of the root. Maximum stress was seen on the inner dentinal wall in case of stainless steel post followed by cast gold and carbon fiber post, both in the models without reinforcement as well as in the reinforced models.

  3. Antimicrobial Effect of Citrus Aurantifolia Extract on Enterococcus Faecalis Within the Dentinal Tubules in The Presence of Smear Layer

    Directory of Open Access Journals (Sweden)

    Sharifian MR

    2011-12-01

    Full Text Available Background and Aims: Instrumentation of the root canals results in formation of smear layer which covers the dentinal tubules. In infected teeth, it is ideal to achieve a material that has the ability to remove the smear layer besides antimicrobial activity. Therefore, this study was designed to evaluate the antimicrobial effect of Citrus aurantifolia extracts (lime juice and rind extract on Enterococcus faecalis within dentinal tubules in the presence of smear layer.Materials and Methods: One-hundred and forty dentin tubes were prepared from bovine incisors. After removal the smear layer, the specimens were infected with Enterococcus faecalis. Then, the smear layer was reformed. Test solutions were used as the irrigants in study roups as follows: group 1: 5.25% NaOCl; group 2: 17% EDTA; group 3: NaOCl+EDTA; group 4: Lime juice; group 5: ethanolic rind extract of C.aurantifolia; group 6: 96% ethanol. Dentin chips were collected from inner and outer layers of dentinal walls and optical density was measured. The data were analyzed using one-way ANOVA and Tamhane tests.Results: In outer layer of dentin, the efficacy of rind extract was less than that of NaOCl+EDTA (P<0.05. Also Lime juice was less effective than EDTA, NaOCl and NaOCl+EDTA (P<0.05. In inner layer of dentin, Lime juice was significantly less effective than NaOCl and NaOCl+EDTA (P<0.05. The efficacy of rind extract was less than that of NaOCl+EDTA (P<0.05.Conclusion: In the presence of smear layer, the antimicrobial activity of Lime juice was less than that of NaOCl but the efficacy of rind extract was similar to that of NaOCl.

  4. 软壁外耳道重建的鼓室成形术%Tympanoplasty with soft-wall reconstruction of ear canal

    Institute of Scientific and Technical Information of China (English)

    孙开; 管国芳; 金春顺; 刘瑶; 张德军; 都延茹; 娄玮; 史平; 孙丽丽

    2011-01-01

    目的:观察软壁外耳道重建的鼓室成形术治疗胆脂瘤中耳炎的疗效.方法:73例(76耳)胆脂瘤中耳炎患者行开放式乳突病变切除鼓室成形术,以耳后肌骨膜瓣行软壁外耳道重建,不做耳甲腔成形术,应用自体乳突皮质骨或砧骨雕刻后行听骨链重建.观察术后外耳道的形态和功能、术后听力以及有无并发症.结果:本组平均干耳时间为术后(21.1士3.1)d.术后外耳道形态基本正常,保持了正常的功能.随访6~24个月,术后气导听力平均改善(14.5士6.1) dB HL.结论:应用耳后肌骨膜瓣行软壁外耳道重建的鼓室成形术能使外耳道的形态和功能基本恢复正常,无需行耳甲腔成形术,听力改善满意.%Objective:To observe the therapeutic effect of tympanoplasty with soft-wall reconstruction of ear canal for chronic otitis media with cholesteatoma. Method: Seventy-three patients(76 ears) suffering from chronic otitis media with cholesteatoma were treated with canal wall down mastoidectomy with tympanoplasty. Postauricu-lar myo-periosteal flap was used to the soft-wall reconstruction of ear canal, and the cavityplasty of auricular con-cha was not performed. The auricular bone prosthesis was made of the autogeneic mastoid cortical bone or residual incus. The postoperative modality and the function of external auditory canal and the postoperative hearing and the postoperative complications were observed. Result:The mean dry ear time was(21. 1±3. 1) days after surgery in this study. The postoperative modality of external auditory canal was normal on the whole. The patients were fol-lowed up between 6 months and 24 months after surgery. The postoperative average air conduction hearing was improved by (14. 5±6. DdB HL. Conclusion: Tympanoplasty with soft-wall reconstruction of ear canal using the postauricular myo-periosteal flap can recover the modality and function of external auditory canal on the whole, and the cavityplasty of auricular

  5. Efficiency of final irrigation of root canal in removal of smear layer

    Directory of Open Access Journals (Sweden)

    Mitić Aleksandar

    2009-01-01

    Full Text Available Introduction A smear layer forms on the root canal walls as the consequence of root instrumentation. The smear layer formed in such a way considerably influences the quality of root obturation and endodontic treatment outcome. Objective The aim of this study was to ultrastructurally analyze the surface of intracanal dentine after removal of the smear layer by the solution of doxycycline, citric acid and detergent Tween-80 (MTAD. Methods The study involved 60 single-rooted, extracted, human teeth divided into four groups. All samples were instrumented by a step-back technique and manual K-files, and rinsed during instrumentation by 2% CHX and H2O2. The first group of samples was exclusively rinsed by CHX and H2O2; in the second group, besides using CHX and H2O2, MTAD solution was used for the final irrigation. The samples which were rinsed by distilled water (+ control and the samples rinsed by 5.25% NaOCl and 17% Na EDTA (-control served as control groups. All samples were observed under the scanning electronic microscope JEOL-JSM-5300. The coronary, middle and apex thirds of the radix region were analyzed. Results The obtained results of the SEM analysis showed that the application of 2% chlorhexidine and hydrogen peroxide did not give clear dentine walls, and the smear layer could not be removed completely. The application of the same combination (CHX and H2O2, added by the final MTAD irrigation solution, led to the efficient removal of the smear layer, while the morphological structure of dentine surface remained unchanged. Statistical analysis showed that canal walls in the experimental group with MTAD as the final irrigation were significantly clearer compared to the control group (p<0.001. Conclusion Based on the obtained results, it can be concluded that MTAD is an efficient solution for the final irrigation of the canal system.

  6. Ex vivo analysis of root canal cleaning using Endo-PTC associated to NaOCl and different irrigant solutions

    Directory of Open Access Journals (Sweden)

    Andrea Kanako Yamazaki

    2010-03-01

    Full Text Available The aim of this study was to assess qualitatively, by means of SEM images, the cleaning of the dentin walls of root canals after chemical-surgical preparation using Endo-PTC cream with 0.5% and 1% sodium hypochlorite and different final irrigating solutions. Seventy-two single-rooted human teeth were divided into eight groups and prepared using Endo-PTC cream with sodium hypochlorite (NaOCl at different concentrations, and irrigated with NaOCl at different concentrations. Final irrigation was performed with either EDTA-T or EDTA-C. The best results were obtained with Group 1, followed by Groups 5, 2, 7, 8, 3, 6 and 4. We can conclude that the use of 0.5% NaOCl during instrumentation and final flush of the root canals was more efficient in cleaning than was 1% sodium hypochlorite. EDTA-T was more efficient in removing smear layer than EDTA-C, and the cervical third presented better cleaning of the root canal walls than did the middle third, which showed cleaner dentin walls than the apical third.

  7. In-vitro evaluation of the effect of canal curvature on adaptation of gutta-percha in canals obturated with HEROfill system by CBCT

    International Nuclear Information System (INIS)

    A hermetic seal of the root canal space following canal preparation is important in endodontics. This study evaluated the effect of canal curve on adaptation of gutta-percha to dentinal walls of canals obturated using the Herofill system. For this in vitro study, 80 mesial roots of mature human first molars with length of 16 mm, curve between 5 deg and 45 deg, and no caries or resorption of the root surface were selected. A cone beam computed tomography system was used to evaluate the presence or absence of a gap in the samples. Photographs were taken in three sections: 2 mm above the curve, at the curve and 2 mm below the curve. The gap area was identified using Photoshop and AutoCAD software. Kruskal Wallis and Mann-Whitney tests were used to analyze the data mounted in a castcurve. There were significant differences between the two lateral condensation groups with various curves; roots with more curve had more gaps. When the Herofill and lateral condensation groups were compared without considering the sections and curve, there was a significant difference between these groups and the Herofill group had less gaps. The Herofill system is an alternative to the lateral condensation technique in severely curved canals. (author)

  8. Coinvasion of dentinal tubules by Porphyromonas gingivalis and Streptococcus gordonii depends upon binding specificity of streptococcal antigen I/II adhesin.

    Science.gov (United States)

    Love, R M; McMillan, M D; Park, Y; Jenkinson, H F

    2000-03-01

    Cell wall-anchored polypeptides of the antigen I/II family are produced by many species of oral streptococci. These proteins mediate adhesion of streptococci to salivary glycoproteins and to other oral microorganisms and promote binding of cells to collagen type I and invasion of dentinal tubules. Since infections of the root canal system have a mixed anaerobic bacterial etiology, we investigated the hypothesis that coadhesion of anaerobic bacteria with streptococci may facilitate invasive endodontic disease. Porphyromonas gingivalis ATCC 33277 cells were able to invade dentinal tubules when cocultured with Streptococcus gordonii DL1 (Challis) but not when cocultured with Streptococcus mutans NG8. An isogenic noninvasive mutant of S. gordonii, with production of SspA and SspB (antigen I/II family) polypeptides abrogated, was deficient in binding to collagen and had a 40% reduced ability to support adhesion of P. gingivalis. Heterologous expression of the S. mutans SpaP (antigen I/II) protein in this mutant restored collagen binding and tubule invasion but not adhesion to P. gingivalis or the ability to promote P. gingivalis coinvasion of dentin. An isogenic afimbrial mutant of P. gingivalis had 50% reduced binding to S. gordonii cells but was unaffected in the ability to coinvade dentinal tubules with S. gordonii wild-type cells. Expression of the S. gordonii SspA or SspB polypeptide on the surface of Lactococcus lactis cells endowed these bacteria with the abilities to bind P. gingivalis, penetrate dentinal tubules, and promote P. gingivalis coinvasion of dentin. The results demonstrate that collagen-binding and P. gingivalis-binding properties of antigen I/II polypeptides are discrete functions. Specificity of antigen I/II polypeptide recognition accounts for the ability of P. gingivalis to coinvade dentinal tubules with S. gordonii but not with S. mutans. This provides evidence that the specificity of interbacterial coadhesion may influence directly the etiology

  9. Use of /sup 99m/Tc-labelled chelates to evaluate their penetration into the dentin

    International Nuclear Information System (INIS)

    The /sup 99m/Tc-labelled EDTA and DPTA complexes proved to be of high purity. After application of the complexes into the root canal their penetration into the dentin was examined autoradiographically

  10. Radicular Dentin Dysplasia Associated with Enamel Hypoplasia

    International Nuclear Information System (INIS)

    The author observed a rare case of radicular dentin dysplasia associated with enamel hypoplasia in a 11-year-old boy with a complaint of gum boil formation. 1. Clinically, yellowish-brown colored teeth with severe attrition and several gum boils were observed. 2. Radiographically, obliteration of pulp chamber and root canal, multiple periapical radiolucencies without obvious cause and blunt roots were observed. 3. Systemically, scalp hair and eyebrows were loose and short. And saddle nose could be also seen.

  11. Contemporary root canal filling strategies

    OpenAIRE

    Moinzadeh, A.T.

    2016-01-01

    Currently, clinicians can choose from a wide range of root canal filling materials and techniques, some of which have been evaluated in this thesis. Methacrylate resin-based sealers suffer from polymerization shrinkage stresses. This limitation may partly be overcome by a two-step cementation procedure. This alternative placement technique results in an increase and homogenization of the adhesion of the material to intraradicular dentin. Subsequent research should aim at developing sealers wi...

  12. Management of incompletely developed teeth requiring root canal treatment.

    Science.gov (United States)

    Harlamb, S C

    2016-03-01

    Endodontic management of the permanent immature tooth continues to be a challenge for both clinicians and researchers. Clinical concerns are primarily related to achieving adequate levels of disinfection as 'aggressive' instrumentation is contraindicated and hence there exists a much greater reliance on endodontic irrigants and medicaments. The open apex has also presented obturation difficulties, notably in controlling length. Long-term apexification procedures with calcium hydroxide have proven to be successful in retaining many of these immature infected teeth but due to their thin dentinal walls and perceived problems associated with long-term placement of calcium hydroxide, they have been found to be prone to cervical fracture and subsequent tooth loss. In recent years there has developed an increasing interest in the possibility of 'regenerating' pulp tissue in an infected immature tooth. It is apparent that although the philosophy and hope of 'regeneration' is commendable, recent histologic studies appear to suggest that the calcified material deposited on the canal wall is bone/cementum rather than dentine, hence the absence of pulp tissue with or without an odontoblast layer. PMID:26923451

  13. The effect of an Nd-YAG pulsed laser on the cleaning of the root canal and the formation of a fused apical plug.

    Science.gov (United States)

    Saunders, W P; Whitters, C J; Strang, R; Moseley, H; Payne, A P; McGadey, J

    1995-07-01

    A Neodymium-yttrium aluminium garnet (Nd-YAG) pulsed laser was used in vitro to determine whether various laser energy levels from 0.75 W to 1.7 W at 15 pulses s(-1) (pps) were able to (i) remove debris from the walls of prepared root canals (ii) remove pulpal tissue from unprepared canals and (iii) create a fused apical plug from dentine chips, hydroxyapatite (HAP) or low-fusing dental porcelain. Single-rooted teeth were sectioned at the amelocemental junction and the crowns discarded. The root canals of 50 teeth were prepared chemomechanically and allocated to four groups of 10 teeth for laser treatment. One group was left unlased as a control. After lasing, the teeth were split longitudinally, stained and examined for residual debris. Results showed that there was no statistically significant difference between the groups (Plaser energy was applied to dentine chips, HAP and low-fusing porcelain in an attempt to produce a fused apical plug. The laser was unable to melt the dentine chips but some hardening of HAP occurred when combined with blue food-colouring, with or without glycerine, at energy levels of 1.0 W, at 15 pps for 30 s. Superficial hardening of low-fusing porcelain occurred at 1.0 W, 15 pps for 30 s.

  14. Capacidade de remoção da smear layer das paredes do canal radicular utilizando o vinagre de álcool e o vinagre de maçã como soluções irrigadoras durante a terapia endodôntica

    OpenAIRE

    Luis Eduardo Duarte Irala; Renata Grazziotin Soares; Alcebíades Nunes Barbosa; Alice Rorig; Jaqueline Peter

    2009-01-01

    The authors analyzed by scanning electron microscopy (SEM) the capacity to remove smear layer of dentin root canal wall after endodontic treatment. The study used premolars extracted human teeth. ProTaper System (Dentsply Maillefer) was used to endodontic instrumentation helpful by five irrigants solutions: sodium hypochlorite 1% + EDTA; sodium hypochlorite 1% + vinegar of apple; vinegar of apple; sodium hypochlorite 1% + vinegar of alcohol and vinegar of alcohol. Root longitudinal-sections w...

  15. Effects of adsorbed and templated nanosilver in mesoporous calcium-silicate nanoparticles on inhibition of bacteria colonization of dentin

    Directory of Open Access Journals (Sweden)

    Fan W

    2014-11-01

    Full Text Available Wei Fan,1,* Daming Wu,1,* Franklin R Tay,2 Tengjiao Ma,1 Yujie Wu,1 Bing Fan1 1The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, People’s Republic of China; 2Department of Endodontics, Georgia Regents University, Augusta, Georgia, USA *These authors contributed equally to this work Abstract: Mesoporous calcium-silicate nanoparticles (MCSNs are advanced biomaterials for controlled drug delivery and mineralization induction. Nanosilver-incorporated MCSNs (Ag-MCSNs were prepared in the present study using both the adsorption and template methods. Both versions of Ag-MCSNs showed characteristic morphology of mesoporous materials and exhibited sustained release of ions over time. In antibacterial testing against planktonic Enterococcus faecalis, Ag-MCSNs showed significantly better antibacterial effects when compared with MCSNs (P<0.05. The Ag-MCSNs aggregated on the dentin surface of root canal walls and infiltrated into dentinal tubules after ultrasound activation, significantly inhibiting the adherence and colonization of E. faecalis on dentin (P<0.05. Despite this, Ag-MCSNs with templated nanosilver showed much lower cytotoxicity than Ag-MCSNs with adsorbed nanosilver (P<0.05. The results of the present study indicated that nanosilver could be incorporated into MCSNs using the template method. The templated nanosilver could release silver ions and inhibit the growth and colonization of E. faecalis both in the planktonic form and as biofilms on dentin surfaces as absorbed nanosilver. Templated Ag-MCSNs may be developed into a new intracanal disinfectant for root canal disinfection due to their antibacterial ability and low cytotoxicity, and as controlled release devices for other bioactive molecules to produce multifunctional biomaterials. Keywords: antibacterial effect, mesoporosity

  16. Permeability of Dentine

    OpenAIRE

    Ghazali, Farid Bin Che

    2003-01-01

    This is an update on the present integrated knowledge regarding dentine permeability that assumed a role in dentine sensitivity and contribute clinically to the effective bonding properties of restorative dental materials. This paper will attempt to refer to in vivo and in vitro studies of dentine permeability and the various interrelated factors governing it.

  17. 完壁式乳突根治鼓室成形术的发展及应用%Development and Application of Canal Wall up Mastoid-tympanoplasty

    Institute of Scientific and Technical Information of China (English)

    宋昱(综述); 马芙蓉(审校)

    2015-01-01

    慢性化脓性中耳炎严重影响患者生活质量,伴胆脂瘤者可能因颅内外并发症危及生命,手术目的为彻底清除病灶,并尽可能保存和重建听力。手术方式主要包括开放式及完壁式乳突根治鼓室成形术,前者在清除病灶方面具有较为广阔的视野,后者术后胆脂瘤复发可能性较高,但因外耳道后壁的保存使患者术后有更高的生活质量。本文对完壁式乳突根治鼓室成形术的术式、手术疗效、术后复发率及手术适应证进行概述,旨在为该术式的选择提供参考。%[Summary] Chronic suppurative otitis media affects patients ’ quality of life, and is life-threatening in patients with cholesteatoma which causes intracranial or extracranial complications .The purpose of surgery is to clear up all the lesions and to reconstruct hearing function .Tympanoplasty is the main surgical method , which includes basically canal wall down ( CWD) and canal wall up (CWU) styles.CWD provides lager surgical field but impairs normal auditory canal structure ; CWU preserves the posterior wall of external auditory canal and provides better quality of life although it has higher possibility of recurrence of cholesteatoma .We reviewed the surgical methods , surgical effects , recurrence rates , and surgical indications of canal wall up mastoid-tympanoplasty , hoping to provide meaningful reference for clinical application .

  18. 完壁式乳突切开鼓室成形术%Intact canal wall mastoidectomy and tympanoplasty in the treatment of chronic suppurative otitis media

    Institute of Scientific and Technical Information of China (English)

    余坤飞; 张松; 熊武; 袁佛良; 吴淑献; 潘松

    2015-01-01

    Objective To report outcomes in patients with active chronic suppurative otitis media treat-ed with intact canal wall mastoidectomy and tympanoplasty. Methods Data from 57 cases treated with intact canal wall mastoidectomy and tympanoplasty were retrospectively reviewed. Result Regarding the tympanic membrane, primary healing was achieved in 48 ears;residual perforation was seen with delayed (2-3 weeks) healing in 5 ears with transplanted fascia;and surgical sites was infected with no tympanic membrane healing in 4 ears. There were no recurrent cases found during the follow-up period of 10 to 34 months. Air-conductive average threshold over 0.5, 1.0, 2.0 and 4.0 kHz improved from 49.7±9.4 dB HL pre-operatively to 30.3±8.0 dB HL postoperatively, with the average air-bone gap reduced by 15 dB. Hearing improvement was reported by the patient in 48 cases. Conclusion Intact canal wall mastoidectomy can be used in active chronic suppura-tive otitis media to effectively remove middle ear lesions and reconstruct middle ear conduction structures, while retaining the normal morphology of ear, improving hearing and enhancing quality of life.%目的:介绍完壁式乳突切开鼓室成形术治疗活动期慢性化脓性中耳炎的临床效果。方法回顾分析我院采用完壁式乳突切开鼓室成形术治疗的57例(耳)活动期慢性化脓性中耳炎的临床资料。结果48耳术后鼓膜一期愈合,5耳移植筋膜边缘残留裂隙,2-3周后延期愈合,4耳术后感染鼓膜穿孔未愈合;随访10个月至34个月,无复发病例,57耳的0.5、1.0、2.0、4.0kHz气导听阈平均值由术前的49.7±9.4 dBHL恢复到30.3±8.0 dBHL,气骨导差平均缩小15 dBHL,其中48耳听力有改善。结论采用完壁式乳突切开鼓室成形术治疗活动期慢性化脓性中耳炎,亦可有效清除中耳乳突病灶,重建中耳传导结构,且能保留耳部正常形态,提升患者听力及生活质量。

  19. Investigations of radicular dentin permeability and ultrastructural changes after irradiation with Er,Cr:YSGG laser and dual wavelength (2780 and 940 nm) laser.

    Science.gov (United States)

    Al-Karadaghi, Tamara Sardar; Franzen, Rene; Jawad, Hussein A; Gutknecht, Norbert

    2015-11-01

    The aim of this study was to assess the effectiveness of dual wavelength (2780 nm Er,Cr:YSGG, 940 nm diode) laser in elimination of smear layer comparing it with Er,Cr:YSGG laser in terms of radicular dentin permeability and ultrastructural changes of root canal walls. Fifty-one sound single-rooted extracted teeth were instrumented up to size F4 and divided into three groups: group Co, non-irradiated samples; group A, irradiated with Er,Cr:YSGG laser; group B, irradiated with the dual wavelength laser. Afterward, the roots were made externally impermeable, filled with 2% methylene blue dye, divided horizontally into three segments reflecting the cervical, middle, and apical thirds then examined under microscope. Using analytical software, the root section area and dye penetration area were measured, and then, the percentage of net dye penetration area was calculated. Additionally, scanning electron microscope investigations were accomplished. Analysis of variance (ANOVA) showed significant differences between all groups over the three root thirds. Dye permeation in dual wavelength laser group was significantly higher over the whole root length: cervical, middle, and apical compared to Er,Cr:YSGG laser group and non-irradiated samples (p laser root canal irradiation produced uneven removal of smear layer, in efficient cleanliness especially in the apical third. There was no sign of melting and carbonization. Within the studied parameters, root canal irradiation with dual wavelength laser increased dentin permeability.

  20. High speed imaging of an Er,Cr:YSGG laser in a model of a root canal

    Science.gov (United States)

    Verdaasdonk, Rudolf; Blanken, Jan; van Heeswijk, Hans; de Roode, Rowland; Klaessens, John

    2007-02-01

    Laser systems of various wavelengths and pulse characteristics have been introduced in dentistry. At present, the range of applications for the different systems is being investigated mainly differentiating between soft and hard tissue applications. For the preparation of root canals both hard and soft tissues are involved. Ideally, one would like to use one laser system for the whole treatment. In this study, we studied the characteristics of the pulsed 2,78 Er,Cr:YSGG laser (Biolase, Waterlase Millenium), in view of root canal cleaning and desinfection. The laser energy was fiber delivered with fiber tip diameters from 400 μm down to 200 μm. Special thermal and high speed imaging techniques were applied in a transparent model of a tapered root canal and slices cut from human teeth. High speed imaging revealed the dynamics of an explosive vapor bubble at the tip of the Er laser in water and the root canal model. Typically for Erbium lasers, within a time span of several hundred μs, a longitudinal bubble expanded to maximum size of 5 mm length and 2 mm diameter at 100 mJ and imploded afterwards. In the root canal, the explosive bubble created turbulent high speed water streaming which resects soft tissue from the hard tissue. Thermal imaging showed the dynamics of all lasers heating of the canal wall up to several mm depending on the wavelength and energy settings. The mechanism of smear layer removal and sterilization in the root canal, is attributed to cavitation effects induced by the pulsed laser. The heat generation into the dentine wall was minimal.

  1. Root canal surface after application of an x-ray opaque waveguide

    Science.gov (United States)

    Dostalova, Tatjana; Jelinkova, Helena; Bartonova, Marie; Sulc, Jan; Nemec, Michal; Koranda, Petr; Miyagi, Mitsunobu; Shi, Yi-Wei; Matsuura, Yuji

    2004-05-01

    The success of endodontic treatment depends on the methods used for shaping, cleaning, disinfecting, and sealing of a root canal. In the last few decades, big progress has been achieved in the application of the following methods: manual instrumentation, sonic and ultrasonic devices, and rotary instruments. The procedures used in the root canal system preparation result in a smear layer creation. The aim of this study was to give more precision to the smear layer removal using laser radiation. The root canal systems of 20 human teeth were treated endodontically. As laser radiation sources, Er:YAG laser system generating a wavelength of 2940 nm (rep. rate 1.5 Hz, spot size diameter 320 um, number of pulses 55, energy 100 mJ) and Alexandrite laser system generating a wavelength of 375 nm (rep. rate 1 Hz, spot size diameter 320 um, number of pulses 200, energy 1 mJ) were used. As a delivery system, a hollow glass waveguide with the special X-ray contrast cover was used. The flexible waveguide was moved via root canal and the laser radiation cleaned the wall surface. After application of Er:YAG laser radiation, the smear layer was fully removed, the surface was clean and smooth, and in the SEM investigation the open dentinal tubules were visible. No cracks were determined. The surface modifications were also not observed after endodontic preparation as well as Alexandrite laser radiation therapy. The whole treatment can be checked by X-ray machine.

  2. Dynamic intratubular biomineralization following root canal obturation with pozzolan-based mineral trioxide aggregate sealer cement.

    Science.gov (United States)

    Yoo, Yeon-Jee; Baek, Seung-Ho; Kum, Kee-Yeon; Shon, Won-Jun; Woo, Kyung-Mi; Lee, WooCheol

    2016-01-01

    The application of mineral trioxide aggregates (MTA) cement during the root canal obturation is gaining concern due to its bioactive characteristic to form an apatite in dentinal tubules. In this regard, this study was to assess the biomineralization of dentinal tubules following root canal obturation by using pozzolan-based (Pz-) MTA sealer cement (EndoSeal MTA, Maruchi). Sixty curved roots (mesiobuccal, distobuccal) from human maxillary molars were instrumented and prepared for root canal obturation. The canals were obturated with gutta-percha (GP) and Pz-MTA sealer by using continuous wave of condensation technique. Canals obturated solely with ProRoot MTA (Dentsply Tulsa Dental) or Pz-MTA sealer were used for comparison. In order to evaluate the biomineralization ability under different conditions, the PBS pretreatment before the root canal obturation was performed in each additional samples. At dentin-material interfaces, the extension of intratubular biomineralization was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy. When the root canal was obturated with GP and Pz-MTA sealer, enhanced biomineralization of the dentinal tubules beyond the penetrated sealer tag was confirmed under the SEM observation (p cement can be used as a promising bioactive root canal sealer to enhance biomineralization of dentinal tubules under controlled environment.

  3. Capacidade de remoção da smear layer das paredes do canal radicular utilizando o vinagre de álcool e o vinagre de maçã como soluções irrigadoras durante a terapia endodôntica

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Duarte Irala

    2009-01-01

    Full Text Available The authors analyzed by scanning electron microscopy (SEM the capacity to remove smear layer of dentin root canal wall after endodontic treatment. The study used premolars extracted human teeth. ProTaper System (Dentsply Maillefer was used to endodontic instrumentation helpful by five irrigants solutions: sodium hypochlorite 1% + EDTA; sodium hypochlorite 1% + vinegar of apple; vinegar of apple; sodium hypochlorite 1% + vinegar of alcohol and vinegar of alcohol. Root longitudinal-sections were obtained and analyzed by SEM. We analyzed three regions of root canal wall: cervical third, the region located 3 mm after the root canal open; apical third, the region located 3 mm short of the apical foramen and middle third. Every samples tested, associated or single, were effectives in removal of smear layer.

  4. 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. PMID:27119760

  5. 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.

  6. 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.

  7. 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.

  8. Gambaran Radiografi Dari Dentin Dysplasia

    OpenAIRE

    Sipayung, Andrew Naro Mario

    2011-01-01

    Dentin dysplasia merupakan salah satu penyakit kelainan herediter secara autosomal dominan pada dentin. Menurut Shields Prevalensi individu yang terjadi pada kasus ini perbandingannya 1:100.000. Secara klinis gambaran dentin dysplasia terlihat normal dan ada perubahan warna gigi yang kekuning-kuningan. Secara radiografi dentin dysplasia tipe I terlihat kelainan perkembangan pada akar dengan hampir tidak ada pembentukan akar sama sekali. Dentin dysplasia tipe II terlihat kelainan perkemban...

  9. The effects of various irrigating solutions on intra-radicular dentinal surface: An SEM analysis

    OpenAIRE

    Karunakaran, J. V.; S.Senthil Kumar; Mohan Kumar; Chandrasekhar, S.; Namitha, D.

    2012-01-01

    Aim: The action of irrigant solutions on intra- radicular dentinal surface were evaluated in an in vitro setting using a scanning electron microscope (SEM) and it was observed that sodium hypochlorite and MTAD produced the cleanest surface and that none of the irrigants were able to produce an ideal preparation of the dentinal surface when used individually. The primary objective of endodontic therapy is to achieve a clean, optimal environment in root canals to avoid unsuccessful treatment ou...

  10. Treatment of dentin hypersensitivity.

    Science.gov (United States)

    Trushkowsky, Richard D; Oquendo, Anabella

    2011-07-01

    Dentinal hypersensitivity is exemplified by brief, sharp, well-localized pain in response to thermal, evaporative, tactile, osmotic, or chemical stimuli that cannot be ascribed to any other form of dental defect or pathology. Pulpal pain is usually more prolonged, dull, aching, and poorly localized and lasts longer than the applied stimulus. Up to 30% of adults have dentinal hypersensitivity at some time. Current techniques for treatment may be only transient in nature and results are not always predictable. Two methods of treatment of dentin hypersensitivity are tubular occlusion and blockage of nerve activity. A differential diagnosis needs to be accomplished before any treatment. PMID:21726693

  11. The effective concentration of red betel leaf (Piper crocatum infusion as root canal irrigant solution

    Directory of Open Access Journals (Sweden)

    Fani Pangabdian

    2012-03-01

    Full Text Available Background: Smear layer is a debris consisting of organic and inorganic particles of calcified tissue, necrotic tissue, pulp tissue, and dentinoblast and microorganism processes that can close the entrance to the dentin tubuli. Smear layer, will not only inhibit the penetration of disinfection materials and sealers to the dentin tubuli, but will also reduce the attachment of root canal filling material so that root canal irrigation solution is needed to dissolve the smear layer. Red betel leaf (Piper crocatum infusion, on the other hand, contains saponin characterized as “surfactants” which can dissolve smear layer. Nevertheless, the effective concentration of the red betel leaf infusion has still not been known clearly. Purpose: This study is aimed to determine the effective concentration of the red betel leaf infusion for cleaning root canal walls from smear layer. Methods: Fiveteen extracted human teeth with straight single roots were randomized into 5 groups (n=3. The specimens were then shaped by using rotary instruments up to a size of 25/.07. During instrumentation, each canal was irrigated with 10, 20, 30 and, 40% red betel leaf infusion for treatment groups, while another was irrigated with aquadest for the control group. Root canal cleanliness was observed by using scanning electron microscope (SEM. Results: There were significant differences among treatment groups (p<0.05, except in the treatment groups irrigated with red betel leaf infusion with concentrations of 30% and 40% (p>0.05. Conclusion: It can be concluded that red betel leaf infusion with a concentration of 30% is effective for cleaning the root canal walls from the smear layer.Latar belakang: Smear layer adalah suatu debris yang mengandung partikel organik dan anorganik dari jaringan terkalsifikasi, jaringan nekrotik, proses dentinoblas, jaringan pulpa dan mikroorganisme yang dapat menutup jalan masuk ke tubuli dentin. Smear layer akan menghalangi penetrasi dari bahan

  12. Dynamic intratubular biomineralization following root canal obturation with pozzolan‐based mineral trioxide aggregate sealer cement

    Science.gov (United States)

    Yoo, Yeon‐Jee; Baek, Seung‐Ho; Kum, Kee‐Yeon; Shon, Won‐Jun; Woo, Kyung‐Mi

    2015-01-01

    Summary The application of mineral trioxide aggregates (MTA) cement during the root canal obturation is gaining concern due to its bioactive characteristic to form an apatite in dentinal tubules. In this regard, this study was to assess the biomineralization of dentinal tubules following root canal obturation by using pozzolan‐based (Pz‐) MTA sealer cement (EndoSeal MTA, Maruchi). Sixty curved roots (mesiobuccal, distobuccal) from human maxillary molars were instrumented and prepared for root canal obturation. The canals were obturated with gutta‐percha (GP) and Pz‐MTA sealer by using continuous wave of condensation technique. Canals obturated solely with ProRoot MTA (Dentsply Tulsa Dental) or Pz‐MTA sealer were used for comparison. In order to evaluate the biomineralization ability under different conditions, the PBS pretreatment before the root canal obturation was performed in each additional samples. At dentin‐material interfaces, the extension of intratubular biomineralization was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy. When the root canal was obturated with GP and Pz‐MTA sealer, enhanced biomineralization of the dentinal tubules beyond the penetrated sealer tag was confirmed under the SEM observation (p cement can be used as a promising bioactive root canal sealer to enhance biomineralization of dentinal tubules under controlled environment. SCANNING 38:50–56, 2016. © 2015 The Authors. Scanning Published by Wiley Periodicals, Inc. PMID:26179659

  13. canal24

    Data.gov (United States)

    California Department of Resources — Canal system center lines in the Central Valley of California and adjacent areas captured from 1:24,000-scale USGS topographic maps. Updates and modifications made...

  14. Assessment of the bacteria reduction in the infected root canal irradiated with diode laser

    International Nuclear Information System (INIS)

    point which width measured 1 mm, approximately. The maximum temperature variation was 7.45 deg C. Under electron microscope scanning, the control groups showed areas with smear layer covering the dentinal walls. The laser irradiated groups showed a smooth, uniform, clean appearance, with small areas of closed dentinal tubules without cracking alternately with areas of exposed open dentinal tubules. Some parts showed fusion of the dentinal mass (groups irradiated with 3 W). In groups where calcium hydroxide was associated with laser irradiation remains were found over the irradiated surface and, in many parts, the dentinal tubules could not be observed. The use of high intensity diode laser at 830 nm proved to be efficient and able to promote reduction in the Enterococcus faecalis population in the infected root canals. (author)

  15. Epidemiology of dentin hypersensitivity

    OpenAIRE

    Splieth, Christian H.; Tachou, Aikaterini

    2012-01-01

    Objective In contrast to the well-established caries epidemiology, data on dentin hypersensitivity seem to be scarce and contradictory. This review evaluates the available literature on dentin hypersensitivity and assesses its prevalence, distribution, and potential changes. Materials and methods The systematic search was performed to identify and select relevant publications with several key words in electronic databases. In addition, the articles’ bibliographies were consulted. Results Prev...

  16. Regional variation in root dentinal tubule infection by Streptococcus gordonii.

    Science.gov (United States)

    Love, R M

    1996-06-01

    The purpose of this study was to investigate the pattern of bacterial invasion of dentinal tubules at different regions in human roots. Specimens were obtained from single-rooted teeth that had their root canals prepared in a standard manner. Roots were then sectioned longitudinally through the canals and the resulting specimens chemically treated to remove the smear layers. Specimens were immersed in a suspension of Streptococcus gordonii for 3 weeks and then prepared for histological analysis. Sections from the cervical, midroot, and apical areas were examined. The pattern of bacterial infection of the cervical and midroot areas was similar, characterized as a heavy infection with bacteria penetrating as deep as 200 microns. Invasion of the apical dentin was significantly different, with a mild infection and maximum penetration of 60 microns.

  17. Morphology of bacterial flora in root canals associated with apical abscesses

    Institute of Scientific and Technical Information of China (English)

    Guo Huijie; Gao Chengzhi; Zhang Chengfei; Zheng Shuying; Yue Lin

    2014-01-01

    Background Apical abscess is an inflammatory process in the peri-radicular tissues caused by biofllms in the necrotic root canal systems.Therefore,a comprehensive analysis of the bacterial colonization is required for a better understanding of the pathogenesis.This study aimed to investigate the patterns of bacterial infection of root canals of teeth with apical abscesses and to determine whether histological and microbiological findings correlated with clinical conditions.Methods Eighteen samples from 18 teeth with apical pathological lesions were analyzed.Nine patients with acute apical abscesses experienced severe pain,and nine patients were asymptomatic with a sinus tract.After extraction,each affected root was divided into two halves.One half was processed for histobacteriologic analysis and examined using light microscopy,and the other half was analyzed using scanning electron microscopy (SEM) to determine the patterns of microbial colonization of the root canals.Results The appearance of each sample subjected to SEM was consistent with the histobacteriologic findings despite the presence or absence of clinical symptoms.Intraradicular biofilms comprising cocci,rods,and/or filaments of amorphous materials were observed in the apical third of the main root canals in all samples.The bacterial biofilms covering the main root canal walls also penetrated the dentinal tubules to varying depths.The morphologies of biofilms varied,and a unique pattern of intraradicular infection was not identified.Conclusion Intraradicular infections formed complex and variable multispecies biofilms and their presence did not correlate with clinical symptoms.

  18. Microhardness of root dentin: effect of endodontic techniques and irrigants

    OpenAIRE

    Muratovska, Ilijana; Atanasovska-Stojanovska, Aneta; Kovacevska, Ivona; Daci, Arijan; Stojanovska, Vera

    2012-01-01

    The Aim of our study is to measure and evaluate the effect of standard step-back (k-file) endodontic technique and rotary (Pro-taper) endodontic technique followed by irrigation with 2,5% Natrium hypohlorite alone or combined with 17% EDTA on microhardness changes of root canal dentin. Method: Forty mandibular human unerupted trird molars were sectioned transversely at the cementoenamel junction and the crowns were discarded.. The data were recorded with Vicker’s ha...

  19. In vitro comparison of antimicrobial effectiveness of QMix and other final irrigants in human root canals

    OpenAIRE

    Ying Liu; Lili Guo; Yuqin Li; Xiangjun Guo; Bin Wang; Ligeng Wu

    2015-01-01

    Final root canal irrigation stands as an effective strategy for eliminating the dentin infection. This study aimed to investigate and compare the antibacterial efficacy of QMix and other four final irrigation regimens in reducing Enterococcus faecalis within human root canals. Single-canal human teeth contaminated with E. faecalis for 4 weeks were prepared chemomechanically with sodium hypochlorite (NaOCl). Then, the teeth were randomly assigned into six groups according to the final irrigati...

  20. Effect of dentin on the antimicrobial efficacy of 3% sodium hypochlorite, 2% chlorhexidine, 17% ethylenediaminetetraacetic acid, and 18% etidronic acid on Candida albicans: An in vitro study

    Science.gov (United States)

    Karale, Rupali; Odedra, Kamal Maldebhai; Srirekha, A.; Champa, C.; Shetty, Ashwija; Pushpalatha, S; Sharma, Rini

    2016-01-01

    Aim: The aim of this study was to evaluate the effect of dentin on the antimicrobial efficacy of 3% sodium hypochlorite, 2% chlorhexidine, 17% EDTA and 18% etidronic acid against C. albicans. Methodology: Dentin powder was prepared from mandibular first premolar using electrical grinder and sterilized. 3% NaOCl, 2%CHX, 17% EDTA and 18% etidronic acid were tested against C. albicans in the presence and absence of dentin, in eppendorf tubes. Group 1 (presence of dentin):- 100ul dentin powder + 100ul C. albicans suspension + 100ul irrigating solution. Group 2 (absence of dentin):- 100ul C. albicans suspension+ 100ul irrigating solution. Control group:- 100ul C. albicans suspension.+ 100ul sterile saline Suspension was thoroughly mixed, submitted for serial dilution upto10-5 after 1 min and colony forming units were counted. Results: In group 2 (without dentin powder), 3% NaOCl and 2% CHX showed the lowest bacterial count compared to group 1 (with dentin powder). Dentin had a significant inhibitory effect on 3% NaOCl (P < 0.001) and 2% CHX (P<0.001). 17% EDTA showed lowest bacterial count in group 1 (with dentin powder) compared to group 2 (without dentin powder). 18% Etidronic acid showed similar bacterial counts in the both the groups. No reduction was observed in the control group. Conclusion: NaOCl & EDTA showed measurable antimicrobial effect even in the presence of dentin which can be promising in the reduction of C. albicans in root canal therapy. PMID:27656066

  1. In vitro study of caries detection through sound dentin using a laser fluorescence device, DIAGNOdent.

    Science.gov (United States)

    Iwami, Yukiteru; Shimizu, Ayako; Yamamoto, Hiroko; Hayashi, Mikako; Takeshige, Fumio; Ebisu, Shigeyuki

    2003-02-01

    The objective of this study was to investigate the feasibility of proximal surface caries detection using a laser fluorescence device, DIAGNOdent, through the sound dentin surrounding the cavity wall after removal of occlusal caries. Extracted sound human molars were ground to prepare horizontal and vertical dentin plates 1.4 mm thick. Extracted carious human molars were reduced in thickness horizontally from the occlusal surfaces until exposure of the dentin caries. The dentin plate was placed on the carious tooth. Before and after gradual thinning of the dentin plate from approximately 1.4 mm to 0.2 mm thick, the dentin caries was measured 10 times through the plate by the laser fluorescence device with a cone-shaped tip or a broad tip. When the dentin plate was reduced to less than 0.3 mm thick (using a combination of a horizontal plate and cone-shaped tip) or 0.2 mm thick (using the other combinations), the values measured with the laser fluorescence device were significantly larger than the values before reducing the thickness of the dentin. Based on these results, the device offers potential use as one of the screening tests for proximal surface caries detection through sound dentin when the sound dentin between tip and caries is thin.

  2. 开放式乳突根治鼓室成形术中乳突术腔复合填塞方法的应用%The combined mastoid cavity obliteration in canal wall down tympanomastoidectomy

    Institute of Scientific and Technical Information of China (English)

    刘稳; 神平; 曹恒明; 李巍; 樊可成; 李培华; 孙海清

    2012-01-01

    目的 探讨开放式乳突根治、鼓室成形术中联合使用自体骨粉、颞肌筋膜、耳后肌骨膜瓣、外耳道皮瓣来缩小术腔容积的方法.方法 回顾性分析179例施行开放式乳突根治、鼓室成形术的患者.研究对象分为2组:复合缩容123例(A组),使用健康骨粉填充上鼓室、鼓窦、窦脑膜角,颞肌筋膜覆盖骨粉及术腔骨质,耳后肌骨膜瓣填充术腔,外耳道皮瓣覆盖下部术腔;常规处理56例(B组),术中仅用颞肌筋膜修补鼓膜、覆盖术腔,未使用骨粉、肌骨膜瓣、皮瓣行术腔复合缩容.随访比较2组术后术腔大小、干耳时间以及术后痂皮生成情况等.结果 A组的术腔容积明显缩小,术后平均干耳时间(6.6±2.3)周,较B组(8.4±2.4)周明显缩短(P<0.01),术后随访基本无痂皮形成,无需反复清理术腔.结论 开放式乳突根治、鼓室成形术中联合使用自体骨粉、颞肌筋膜、耳后肌骨膜瓣、外耳道皮瓣来缩小术腔体积,能够缩短干耳时间、减少术后痂皮形成.%Objective To describe the technique for mastoid cavity obliteration in canal wall down tympanomastoid ectomy using autologous bone chips , temporal myofascial flap, musculoperiosteal flap , and ear canal skin flap. Methods Retrospective analysis based on 179 cases of chronic otitis media treated with canal wall down tympanomastoidectomy . Subjects were divided into 2 groups by the methods of mastoid cavity obliteration . 123 cases (group A) were treated with combined mastoid cavity obliteration using autologous bone chips , temporal myofascial flap, musculoperiosteal flap, and ear canal skin flap; 56 cases ( group B) were treated with routine therapy without combined mastoid cavity obliteration . Postoperative dry ear time and mastoid cavity size were compared between the two groups . Results The mastoid cavity size of group A was much smaller than group B and the average dry ear time of group A was much shorter than group B

  3. The cleanliness differences of root canal irrigated with 0.002% saponin of mangosteen peel extract and 2.5% NaOCl

    Directory of Open Access Journals (Sweden)

    Anis Sakinah

    2015-06-01

    Full Text Available Background: Root canal treatment consists of preparation, sterilization, and obturation. During root canal preparation, debris is smeared over the dentinal surface forming a smear layer. Smear layer will reduce the attachment of root canal filling materials. Organic material in smear layer can be substrated for microorganism. Preparation of root canal should be followed by irrigation. NaOCl is common irrigation solution in endodontics. It has been very effective for their disinfecting and tissue-dissolving properties, but it is incapable of removing the smear layer. On the other hand, saponin of mangosteen peel extract has an ability as a surfactant to lower the surface tension, and it can dissolve debris containing of anorganic and organic materials. Purpose: This study aims to know the differences between 2.5% NaOCl and 0.002% saponin of mangosteen peel extract in removing the debris in the root canal after the preparation procedure. Method: Three groups of teeth (7 teeth in each were instrumented with K-file and irrigated as follow: group 1 (control with aquadest; group 2 with 2.5% NaOCl; and group 3 with 0.002% saponin of mangosteen peel extract. Furthermore, those teeth were split horizontally and longitudinally 4mm above the apical. The apical third of root canal walls was observed by a scanning electron microscope (SEM. Result: There were significant differences between each group (p<0.05. Median value of the group 3 was score 1 considered as the smallest value. It indicates that Group 3 with 0.002% saponin of mangosteen peel extract was the cleanest group. Conclusion:It can be concluded that 0.002% saponin of mangosteen peel extract can clean the smear layer of the root canal better than 2.5% NaOCl.

  4. Scalloping at the lumbosacral canal

    International Nuclear Information System (INIS)

    Scalloping is an indentation of the dorsal side of the vertebral body (anterior wall of the lumbosacral or sacral canal) which typically involves several adjacent lumbal vertebral body segments and the anterior wall of the canalis sacralis. Occurrence without underlying disease is rare; it occurs most frequently with chondrodystrophy, neurofibromatosis, Morquio's syndrome, Hurler's syndrome, acromegaly, Ehlers-Danlos syndrome, Marfan's syndrome, cysts, tumors and in peridural lipomas. (orig.)

  5. Scalloping at the lumbosacral canal

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, R.

    1987-07-01

    Scalloping is an indentation of the dorsal side of the vertebral body (anterior wall of the lumbosacral or sacral canal) which typically involves several adjacent lumbal vertebral body segments and the anterior wall of the canalis sacralis. Occurrence without underlying disease is rare; it occurs most frequently with chondrodystrophy, neurofibromatosis, Morquio's syndrome, Hurler's syndrome, acromegaly, Ehlers-Danlos syndrome, Marfan's syndrome, cysts, tumors and in peridural lipomas.

  6. wall

    Directory of Open Access Journals (Sweden)

    Irshad Kashif

    2016-01-01

    Full Text Available Maintaining indoor climatic conditions of buildings compatible with the occupant comfort by consuming minimum energy, especially in a tropical climate becomes a challenging problem for researchers. This paper aims to investigate this problem by evaluating the effect of different kind of Photovoltaic Trombe wall system (PV-TW on thermal comfort, energy consumption and CO2 emission. A detailed simulation model of a single room building integrated with PV-TW was modelled using TRNSYS software. Results show that 14-35% PMV index and 26-38% PPD index reduces as system shifted from SPV-TW to DGPV-TW as compared to normal buildings. Thermal comfort indexes (PMV and PPD lie in the recommended range of ASHARE for both DPV-TW and DGPV-TW except for the few months when RH%, solar radiation intensity and ambient temperature were high. Moreover PVTW system significantly reduces energy consumption and CO2 emission of the building and also 2-4.8 °C of temperature differences between indoor and outdoor climate of building was examined.

  7. Biocompatibility of dental materials used in contemporary endodontic therapy: a review. Part 2. Root-canal-filling materials.

    Science.gov (United States)

    Hauman, C H J; Love, R M

    2003-03-01

    Root-canal-filling materials are either placed directly onto vital periapical tissues or may leach through dentine. The tissue response to these materials therefore becomes important and may influence the outcome of endodontic treatment. This paper is a review of the biocompatibility of contemporary orthograde and retrograde root-canal-filling materials.

  8. 开放式鼓室成形术听力重建效果的分析%Analysis of auditory outcomes in canal wall down tympanoplasty with ossiculoplasty

    Institute of Scientific and Technical Information of China (English)

    郭敛容; 胡洪义; 苏永进

    2011-01-01

    目的 比较自体骨及钛金属两种听力重建材料在开放式鼓室成形术后的听力改善状况.方法 对2007年10月~2010年5月接受开放式鼓室成形术的21例(21耳)进行回顾性分析,根据听骨链重建材料分为自体骨组和金属钛组,听力统计以0.5,1,2,4 kHz的平均气骨导差值计算.结果 自体骨组术后平均气骨导差和术前比较无明显统计学差异,金属钛组术后平均气骨导差较术前缩小(27.5±7.25)dB,两组比较差异有统计学意义.结论 在开放式鼓室成形术中,使用金属钛重建听力链的听力改善较自体骨好.%Objective To compare the hearing improvement in canal wall down tympanoplasty with autologous bone or titanium prostheses. Methods The data of 2 1 cases underwent canal wall down tympanoplasty since October 2007 to May 2010 was retrospectively analysed. The patients were divided into 2 groups : autologous bone group and titanium prostheses group. The average postoperative air - bone gaps (A - BC ) of four frequencies : 0.5,1, 2 , 4 kHz were measured. Results There was no significant hearing improvement in autologous bone group . The postoperative A - BC in titanium prostheses group significantly reduced by 2 7 . 5 ± 7.25 dB. Conclusions The hearing improvement in canal wall down tympanoplasty with titanium prostheses was better than with autologous bone.

  9. X-ray microanalysis of dentin: a review

    International Nuclear Information System (INIS)

    The aim of this review was to present a condensed summary of the literature on X-ray microanalysis of dentin, including both energy-dispersive (EDS) and wavelength-dispersive (WDS) analysis. Estimations of concentrations by XMA of dentin should be regarded as semiquantitative values. The Ca level in rat odontoblasts was elevated in the secreting end of the cell body. In predentin Ca accumulated at a concentration of 2% that of mineralized dentin. In coronal dentin the peritubular areas were hypermineralized (Ca, P, Mg). Primary caries lesions showed a decrease of Ca, P, Mg and Cl, and usually an increase of S and Zn. The mineralized surface often present contained especially high concentrations of F and K. Considerable uptake of various ions in cavity walls exposed to filling materials was assessed: from silver amalgam, Zn and Sn, from silicate cement and glassionomer cement F, Al and Zn, and from zinc oxide-eugenol cement, Zn. The highest F concentrations following topical application were found with solutions of TiF4 and with the varnishes Duraphat and Fluor Protector. Dentin wall lesions adjacent to amalgam fillings exhibited considerably reduced Ca and P values, but concomitantly considerable amounts of Zn and Sn, that explained the increased radiopacity seen in some microradiographs. 84 references

  10. X-ray microanalysis of dentin: a review

    Energy Technology Data Exchange (ETDEWEB)

    Hals, E.; Tveit, A.B.; Totdal, B.

    1988-03-01

    The aim of this review was to present a condensed summary of the literature on X-ray microanalysis of dentin, including both energy-dispersive (EDS) and wavelength-dispersive (WDS) analysis. Estimations of concentrations by XMA of dentin should be regarded as semiquantitative values. The Ca level in rat odontoblasts was elevated in the secreting end of the cell body. In predentin Ca accumulated at a concentration of 2% that of mineralized dentin. In coronal dentin the peritubular areas were hypermineralized (Ca, P, Mg). Primary caries lesions showed a decrease of Ca, P, Mg and Cl, and usually an increase of S and Zn. The mineralized surface often present contained especially high concentrations of F and K. Considerable uptake of various ions in cavity walls exposed to filling materials was assessed: from silver amalgam, Zn and Sn, from silicate cement and glassionomer cement F, Al and Zn, and from zinc oxide-eugenol cement, Zn. The highest F concentrations following topical application were found with solutions of TiF4 and with the varnishes Duraphat and Fluor Protector. Dentin wall lesions adjacent to amalgam fillings exhibited considerably reduced Ca and P values, but concomitantly considerable amounts of Zn and Sn, that explained the increased radiopacity seen in some microradiographs. 84 references.

  11. Fiber-post bond strength in canals obturated with a cross-linked gutta-percha core obturator.

    Science.gov (United States)

    Scotti, Nicola; Coero Borga, Francesco A; Alovisi, Mario; Bergantin, Emanuele; Marchionni, Silvia; Pasqualini, Damiano; Berutti, Elio

    2014-04-01

    The aim of this in-vitro study was to evaluate the bond strength of fiber posts cemented in a root canal filled using various root-canal obturation techniques. A total of 33 monoradicular samples, treated endodontically, were randomly assigned to three groups according to the root-canal obturation technique: group 1, continuous-wave technique; group 2, plastic-obturator-core technique; and group 3, cross-linked gutta-percha obturator-core technique. Fiber posts were luted in each sample and each was sectioned perpendicular to the post axis. The push-out test was performed using a universal machine and the maximum failure load was recorded in MPa mm(-2) . Several samples were randomly chosen for scanning electron microscopy evaluation. The mean debris and dentinal tubule-opening scores were calculated separately in the coronal and apical portions. Bond strength was significantly higher in group 1 than in groups 2 and 3. Debris scores were significantly higher in the apical portion of groups 2 and 3 than in group 1. Within the limitations of this study it can be affirmed that thermoplasticized alpha gutta-percha seemed to worsen the cleaning of post-space walls and hence reduced fiber-post bond strength.

  12. Canal-wall-down mastoidectomy and tympanoplasty surgery preserving chorda tympani nerve integrality%保留鼓索神经的开放式乳突根治鼓室成形术

    Institute of Scientific and Technical Information of China (English)

    王林娥; 张汝祥; 张道行

    2012-01-01

    目的:报告开放式乳突根治鼓室成形术中寻找鼓索神经的方法和保留鼓索神经的意义.方法:66例慢性化脓性中耳炎或中耳胆脂瘤患者,术中以砧骨短突为标志,磨低外耳道后壁,沿面神经垂直段找到鼓索嵴(鼓索神经出骨管处),沿鼓索嵴找到游离于鼓室内的鼓索神经,仔细清理鼓索神经表面的病变组织,保持其完整性.结果:24例中耳胆脂瘤患者和42例慢性化脓性中耳炎患者鼓索神经表面胆脂瘤上皮及肉芽彻底清理,无一例鼓索神经断裂,患者术后味觉无明显变化.结论:开放式乳突根治鼓室成形术中彻底清理病变的同时保持鼓索神经的完整性,保留了鼓索神经的结构和功能,可以减低移植于镫骨头上的听小骨膺复物脱落的危险,且可对移植筋膜起支架作用.%Objective:To report the way for searching the chorda tympani nerve and the significance for preserving the chorda tympani nerve during canal'wall-down mastoidectomy and tympanoplasty surgery. Method:Sixty-six cases with chronic suppurative otitis media underwent canal-wall-down mastoidectomy and tympanoplasty surgery. According to the marker of the short crus of incus, the posterior wall of auditory canal was lowered and crista of the chorda tympani nerve was found through tracing the facial nerve contour. The chorda tympani nerve was preserved after clearing the surrounding tissue. Result: Among the 66 cases, 24 cases had middle ear chol-esteatoma,42 cases had granulation in middle ear. The cholesteatoma and granulation on the surface of the chorda tympani nerve were cleared thoroughly. No neurotmesis or obvious change of taste occurred after operation. Conclu sion: Canal-wall-down mastoidectomy and tympanoplasty surgery preserving chorda tympani nerve integrality may preserve the structure and function of the chorda tympani nerve , reduce the risk of ossicle extrusion above the head of stapes and serve as a frame for transplanting

  13. Holmium:YAG laser in dentistry: photoconditioning of dentinal surfaces

    Science.gov (United States)

    Holt, Raleigh A.; Nordquist, Robert E.

    1994-09-01

    This in vitro study was undertaken to determine energy levels necessary to produce tubule closure and surface smoothing on dentinal surfaces of human teeth and their resultant temperature increases within the pulpal canals with the Holmium:YAG laser. An optimal working spot size and even absorption pattern were produced by defocusing the laser beam and evaluated by images produced on light exposed and developed photographic paper. The surface effects on dentin were examined by scanning electron microscopy. A thermocouple was positioned in the canals of fresh dissected dog jaws and attached to a recorder which produced a graph of the temperature changes. The in vitro research model for intrapulpal temperatures changes was verified by comparing premortem and postmortem temperature readings. The same protocol was used to evaluate temperature changes in fresh human extracted teeth. In vivo histological studies were conducted to evaluate the effects of HO:YAG laser energy on pulpal tissues. The results of these studies indicate the HO:YAG laser at a wavelength of 2.12 microns can be safely and effectively used for photoconditioning of the dentinal surfaces of teeth in clinical conditions.

  14. A scanning electron microscopic evaluation of different root canal irrigation regimens Avaliação por microscopia eletrônica de varredura de diferentes regimes irrigantes no canal radicular

    Directory of Open Access Journals (Sweden)

    Chaves Medici Mônika

    2006-09-01

    Full Text Available The purpose of this study was to assess the effectiveness of endodontic irrigants in removing the smear layer from instrumented root canal walls using Scanning Electron Microscopy (SEM. The endodontic irrigants used were: 1% sodium hypochlorite (NaOCl; 1% NaOCl mixed to 17% EDTAC; 2% chlorhexidine gel; and Ricinus communis gel. Photomicrographs of the middle and apical thirds were evaluated with the aid of the Fotoscore - v. 2.0 software. The results indicated that the mixture of sodium hypochlorite and EDTAC completely removed the smear layer from dentinal walls. The other endodontic irrigants were not as efficient in cleansing the root canals.A proposta deste estudo foi avaliar, por meio de microscopia eletrônica de varredura (MEV, a efetividade dos irrigantes endodônticos na remoção da "smear layer" das paredes dos canais radiculares instrumentados. Os irrigantes endodônticos utilizados foram: solução de hipoclorito de sódio a 1%; solução de hipoclorito de sódio a 1% misturado ao EDTAC a 17%, gel de clorexidina a 2% e gel de Ricinus communis. Fotomicrografias dos terços médio e apical foram avaliadas com o auxílio do software Fotoscore - versão 2.0. Os resultados indicaram que a mistura da solução de hipoclorito de sódio e EDTAC removeu eficientemente a "smear layer" das paredes dentinárias. Os demais irrigantes endodônticos não foram tão eficientes na limpeza dos canais.

  15. Ex Vivo Evaluation of the Root Form and Root Canal Morphology of the Mandibular First Molar Using CBCT Technology

    OpenAIRE

    Narges Farhad-Mollashahi; Eshagh Ali Saberi; Mahdi Niknami; Elnaz Mousavi; Hossein Rasuli

    2014-01-01

    Background: This study aims to evaluate the root canal system and its curvature and the relationship between the root concavity and the dentin thickness of danger zone in the mandibular first molar using the cone beam CT method. Materials and Methods: A sum of 101 fresh extracted mandibular first molar were gathered and scanned by CBCT (planmeca romexis 3D) machine. The root canal configuration was evaluated according to Vertucci’s classification. Then, the canal curvature was evaluated a...

  16. Evaluation of the antimicrobial effect of super-oxidized water (Sterilox® and sodium hypochlorite against Enterococcus faecalis in a bovine root canal model

    Directory of Open Access Journals (Sweden)

    Giampiero Rossi-Fedele

    2010-10-01

    Full Text Available ABSTRACT Ideally root canal irrigants should have, amongst other properties, antimicrobial action associated with a lack of toxicity against periapical tissues. Sodium hypochlorite (NaOCl is a widely used root canal irrigant, however it has been shown to have a cytotoxic effect on vital tissue and therefore it is prudent to investigate alternative irrigants. Sterilox's Aquatine Alpha Electrolyte® belongs to the group of the super-oxidized waters; it consists of a mixture of oxidizing substances, and has been suggested to be used as root canal irrigant. Super-oxidized waters have been shown to provide efficient cleaning of root canal walls, and have been proposed to be used for the disinfection of medical equipment. OBJECTIVE: To compare the antimicrobial action against Enterococcus faecalis of NaOCl, Optident Sterilox Electrolyte Solution® and Sterilox's Aquatine Alpha Electrolyte® when used as irrigating solutions in a bovine root canal model. METHODOLOGY: Root sections were prepared and inoculated with E. faecalis JH2-2. After 10 days of incubation the root canals were irrigated using one of three solutions (NaOCl, Optident Sterilox Electrolyte Solution®and Sterilox's Aquatine Alpha Electrolyte® and subsequently sampled by grinding dentin using drills. The debris was placed in BHI broth and dilutions were plated onto fresh agar plates to quantify growth. RESULTS: Sodium hypochlorite was the only irrigant to eliminate all bacteria. When the dilutions were made, although NaOCl was still statistically superior, Sterilox's Aquatine Alpha Electrolyte® solution was superior to Optident Sterilox Electrolyte Solution®. CONCLUSIONS: Under the conditions of this study Sterilox's Aquatine Alpha Electrolyte® appeared to have significantly more antimicrobial action compared to the Optident Sterilox Electrolyte Solution® alone, however NaOCl was the only solution able to consistently eradicate E. faecalis in the model.

  17. Age-related changes in ac-impedance spectroscopy studies of normal human dentine: further investigations.

    Science.gov (United States)

    Eldarrat, A H; High, A S; Kale, G M

    2010-01-01

    One of the age-related changes occurring in dentine structure is the formation of peritubular dentine on the inner walls of dentinal tubules leading to complete closure of tubules. Ac-impedance is safe, fast and non-invasive technique. In the last decade, the popularity of the technique has increased in dental research. Several investigators have used the technique to detect tooth cracks and caries. The results of in vitro studies showed that ac-impedance technique was more advanced for caries detection than visual and radiographic methods. However, other studies demonstrated that the accuracy of impedance measurements can be affected by many factors such as remineralization after tooth eruption. A study has been published on effect of age on impedance measurements by the authors for two age groups by employing ac-impedance spectroscopy. Therefore, the aim of this study was to demonstrate the importance of this technique by conducting further investigations on dentine samples of wider age groups. Dentine samples were prepared from extracted sound third molars of known patient age. The ac-impedance measurements were carried out over a wide range of frequency. After performing all electrical measurements, dentine samples were examined under SEM to correlate the electrical measurements with their structure. Impedance measurements showed that there were differences in impedance between young and old dentine. One-way ANOVA of the means of resistance and capacitance for all age groups (20, 25, 30, 40 and 50 years old dentine) revealed a significant difference (ANOVA, P < 0.0001) as a function of age. Applying Tukey's post hoc test, to the same data showed that this difference was due to the 50 years old dentine for resistance and was due to the 40 and 50 years old dentine for capacitance which were statistically different to all other groups. SEM investigation of dentine samples showed that young dentine is characterized by open dentinal tubules distributed all over the

  18. A comparison of stainless steel and nickel-titanium K-files in curved root canals.

    Science.gov (United States)

    Chan, A W; Cheung, G S

    1996-11-01

    The purpose of this study was to determine the effects of hand instrumentation using traditional stainless steel K-files and nickel-titanium K-files on the final shape of curved root canals. A total of 24 moderately curved canals in the mesial roots in extracted human mandibular first molars were randomly divided into two groups. These were instrumented manually using either stainless steel or nickel-titanium, K-files with the stepdown technique. The cross-sectional shape of each canal at three different horizontal levels were captured, before and after instrumentation, into a computer for comparison using image analyser software. Three parameters at each level were evaluated: (i) amount of dentine removed; (ii) least remaining dentine thicknesses on mesial and furcal aspects; and (iii) the amount and direction of canal transportation. The results showed that the two file types removed similar amounts of dentine at all three levels examined. The nickel-titanium files left a thicker layer of dentine on both the mesial and furcal aspects than stainless steel files. However, the difference was not significant (pooled T-test, P > 0.05). Both types of files transported the centre of the canals but the nickel-titanium instrument seemed to be safer because of the reduced amount of transportation towards the danger areas. PMID:10332236

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

    Science.gov (United States)

    Neves, Pierre Adriano Moreno; Lima, Leonardo Abrantes; Rodrigues, Fernanda Cristina Nogueira; Leitão, Tarcisio Jorge; Ribeiro, Cecília Cláudia Costa

    2016-05-20

    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. PMID:27223131

  20. Immediate Dentin Bond Strength of Self-etch Dentine Adhesives

    Directory of Open Access Journals (Sweden)

    David Lafuente

    2014-02-01

    Full Text Available Purpose: The purpose of this study was to evaluate the immediate bond strength of two sixth generation and two seventh generation dentin bonding agents to superficial dentin. Specimens were prepared to exposed superficial dentin and either Clearfil SE, Clearfil S3, Adper Prompt-l-pop of G-bond was applied over the dentin surface and light cured. Then composite resin was applied to the treated surface and light-cured in two increments. Specimens were tested 15 minutes after they were made for shear bond strength at 0.01 cm/min. Clearfil SE had statistically higher bond strength than the other three adhesives evaluated (42.9 MPa. There was no statistical difference among Clearfil S3, Adper Prompt-l-pop and G-Bond. The dentin adhesive with an application of an acidic primer before the application of the adhesive showed better immediate bond strength.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Canals in the Roof of the Pharynx :Anatomic Study and their Clinical Meaning

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionThe palatovaginal canal and the vomerovaginal canal are small canals which connect the roof of the nasopharynx to the posterior wall of the pterygopalatine fossa. The pterygopalatine fossa represents a major pathway for spread of malignant tumors and infections. In most of the classic anatomy texts brief descriptions of the palatovaginal canal and the vomerovaginal canal are provided. There is still a scarcity of studies comparing the radiologic and microdissection findings~([1]). The aim of t...

  3. Diffusion of calcitonin through the wall of the root canal Avaliação da difusão da calcitonina através da dentina radicular

    Directory of Open Access Journals (Sweden)

    Selma Cristina Cury Camargo

    2004-03-01

    Full Text Available The aim of this study was to evaluate the in vitro diffusion of synthetic salmon calcitonin (CT, used as an intracanal medication, to the external root surface, with or without the presence of intact root cementum. Fifty-four human central incisors were used in the experiment, and were divided into two groups of 21 (test groups and two groups of 6 teeth (control groups. After root canal preparation, 10 ml of calcitonin was inserted within the root canal chamber. The root was sealed and made externally impermeable. Specimens were then placed in tubes with saline solution buffered with phosphates and stored at 37°C. The diffusion of calcitonin was measured after 1, 4 and 7 days. To count calcitonin present at the external media (PBS, ELISA test (an antigen-antibody reaction was used. Results showed that there was calcitonin diffusion through dentin in all of the test samples. The absence of cementum increased the diffusion of calcitonin (p=0.05. The highest counts of CT were obtained on day 7 for groups with or without cementum - showing a direct relation between time and diffusion of the medication.O presente estudo determinou in vitro a difusão da calcitonina sintética de salmão, como medicação intracanal, até a superfície externa radicular, com e sem a presença de cemento radicular. Foram utilizados cinqüenta e quatro incisivos centrais humanos, divididos em dois grupos com 21 dentes cada e dois grupos com 6 dentes cada (controle negativo. Após o preparo endodôntico, os dentes receberam 10 ml de calcitonina como medicação intracanal. Feitos o selamento e a impermeabilização externa da raiz, os espécimes foram acondicionados em tubos com solução salina tamponada com fosfatos e incubados em estufa a 37°C. Foram colhidas amostras da solução salina nos períodos de 1, 4 e 7 dias. Para a análise das soluções teste, utilizou-se teste ELISA. Os resultados mostram que existe a difusão da medicação testada até a superf

  4. The Effect of Smear Layer on Antimicrobial Efficacy of Three Root Canal Irrigants

    OpenAIRE

    Zargar, Nazanin; Dianat, Omid; Asnaashari, Mohammad; Ganjali, Mojtaba; Zadsirjan, Saeede

    2015-01-01

    Introduction: One of the main goals of endodontic treatment is to decrease the harboring bacteria within the root canal system and dentinal tubules. This experimental study attempted to investigate the antibacterial efficacy of three root canal irrigants in the presence and absence of smear layer (SL). Methods and Materials: A total of 210 sound extracted human single-rooted teeth were prepared. After creating the SL and its removal in half of the samples, they were infected with Candida albi...

  5. Root canal irrigants

    OpenAIRE

    Kandaswamy Deivanayagam; Venkateshbabu Nagendrababu

    2010-01-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are...

  6. The Comparative Efficacy of Different Files in The Removal of Different Sealers in Simulated Root Canal Retreatment- An In-vitro Study

    Science.gov (United States)

    Kanaparthy, Aruna

    2016-01-01

    Introduction Root canal treatment enjoys a high success rate all over the world and has saved billions of teeth from extraction. However, there are instances of failure, the main causes being insufficient cleaning and inadequate obturation. In such cases the most conservative treatment option would be non-surgical retreatment. It requires regaining access to the entire root canal system through removal of the original root canal filling thus permitting further cleaning and re- obturation. Removal of gutta-percha and sealer becomes a critical step to gain access to the root canal system, remove necrotic tissue debris, bacteria and infected dentin. Aim To compare and evaluate the efficacy of manual hand Hedstrom files and two rotary retreatment file systems ProTaper Universal retreatment files and MtwoR (retreatment) files in the removal of root canal filling material during root canal retreatment and the influence of the type of sealers zinc oxide eugenol and AH plus on the presence of remaining debris in the reinstrumented canals in the apical, middle and coronal third. Materials and Methods Sixty single rooted human premolar teeth were divided into 3 Groups of 20 teeth each Group I (20 Teeth): prepared using hand K Files, Group II (20 Teeth): prepared using ProTaper rotary system and Group III (20 Teeth): prepared using Mtwo rotary system. In Groups- IA, IIA, IIIA: (10 teeth each) Obturation was done using Zinc Oxide Eugenol sealer and gutta percha. In Groups- IB, IIB, IIIB: (10 teeth each) obturation was done with AH Plus sealer and gutta percha. All the teeth were subjected to retreatment. Groups IA and IB with Hedstrom files, Groups IIA and IIB with ProTaper retreatment files and for Groups IIIA and IIIB with Mtwo retreatment Files. The roots were longitudinally split and were observed under a stereomicroscope for remaining amount of filling material on the canal walls. Statistical analysis was done using One–way ANOVA (Analysis of variance) test and Tukey

  7. Hereditary dentine disorders: dentinogenesis imperfecta and dentine dysplasia

    OpenAIRE

    MacKie Iain; McDonnell Sinead T; Barron Martin J; Dixon Michael J

    2008-01-01

    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 cham...

  8. Clinical application of pedicle retroauricular flap in canal wall-down tympanoplasty%耳后带蒂皮瓣在开放式鼓室成形术中的应用

    Institute of Scientific and Technical Information of China (English)

    黄永久; 鲍学礼

    2011-01-01

    Objective To explore the practical restorative procedure for tissue defect in canal wall-down (CWD) tympanoplasty based on a clinical trial. Methods Included in this study were 26 cases, among them 22 cases with cholesteatoma in the middle ear cleft and 4 with chronic suppurative otitis media, all treated by CWD type of tympanoplasty with pedicle retroauricular flap transplanting to repair the tissue defect in the operative cavity. Then, all these cases were followed up for 1 to 15 years to observe the therapeutic outcomes for evaluating the restorative effect on these cases. Results All the flaps were survived among these cases, with their operative cavities all clearing and dried in a period of one month and no granulation growing. During the following up period, it was found that the operated mastoid cavity were almost vanished in all of them, with a slightly wider external auditory meatus present when compared with that of the opposite side, covered with smooth and clear skin on the reconstructed posterior canal wall, and improved postoperative hearing level at different degrees. Conclusions The tissue defect in the operative cavity, met during CWD type of tympanoplasty, can be repaired with a pedicle retroauricular flap in a simple and convenient way to improve the survival rate of the flap to a higher level and to shorten the period of ear drying for avoiding granulation growing in the operative cavity.%目的 探讨开放式鼓室成形术中上皮缺损的有效修复方法.方法 26例开放式鼓室成形术患者,应用耳后带蒂皮瓣一期修复术腔上皮缺损,系统观察修复效果.结果 所有患者皮瓣全部成活,均在1月内干耳,术腔无肉芽生长.术后随访1~16年,全部患者乳突术腔基本消失,外耳道略宽,后壁皮肤光滑、洁净,术后听力均有不同程度提高.结论 对于开放式鼓室成形术中出现的上皮缺损,耳后带蒂皮瓣修复法简单方便,成活率高,有利于缩短干耳时间.

  9. The effects of various irrigating solutions on intra-radicular dentinal surface: An SEM analysis

    Directory of Open Access Journals (Sweden)

    J V Karunakaran

    2012-01-01

    Full Text Available Aim: The action of irrigant solutions on intra- radicular dentinal surface were evaluated in an in vitro setting using a scanning electron microscope (SEM and it was observed that sodium hypochlorite and MTAD produced the cleanest surface and that none of the irrigants were able to produce an ideal preparation of the dentinal surface when used individually. The primary objective of endodontic therapy is to achieve a clean, optimal environment in root canals to avoid unsuccessful treatment outcomes. The complexities of the root canal system necessitate the use of irrigating solutions which act on radicular dentin surface, modifying it. The action of irrigants can be beneficial, and yet at the same time, as they modify the surface structure of dentin, they can have an adverse impact on the properties of dentin. The present study was undertaken to assess the effect of various irrigants on the dentinal surface using an SEM. Materials and Methods: Forty-five roots were randomly divided into nine groups (n=5 and prepared by sectioning at the level of cemento-enamel junction (CEJ and 10 mm from the CEJ and split longitudinally. The dentin surface was prepared and the cemental surfaces were coated with double layer of varnish. The irrigants tested were normal saline, de-ionized water, 17% ethylenediaminetetraacetic acid (EDTA, 5% sodium hypochlorite (NaOCl, 5% NaOCl with ultrasonic agitation, 3% hydrogen peroxide, 2% chlorhexidine (CHX, MTAD, and MTAD with ultrasonic agitation. The prepared samples were placed in the irrigant solution for 3 min, subsequently dehydrated, sputter coated, and observed under SEM. The images were subsequently analyzed for dentinal surface changes. Results: 17% EDTA and MTAD produced the cleanest dentinal surface. Ultrasonic agitation enhanced the effect of irrigants. 5% NaOCl and 3% hydrogen peroxide were efficient at removal of organic debris, but were unable to remove the smear layer. De-ionized water, normal saline, and 2

  10. Evaluation of a Sonic Device Designed to Activate Irrigant in the Root Canal

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Verhaagen, Bram; Versluis, Michel; van der Sluis, Lucas W. M.

    2010-01-01

    Introduction: The aims of this study were to evaluate the removal of dentin debris from the root canal by sonic or ultrasonic activation of the irrigant and the physical mechanisms of sonic activation by visualizing the oscillations of the sonic tip, both inside and outside the confinement of the ro

  11. 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.)

  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. 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

  14. 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.

  15. [Retrograde root filling utilizing resin and a dentin bonding agent: indication and applications].

    Science.gov (United States)

    Rud, J; Rud, V; Munksgaard, E C

    1989-05-01

    With Gluma a methacrylate-based resin may be chemically bonded to dentin with considerable strength. Resin may therefore be used for retrograde root fillings. Whereas a retrograde amalgam filling demands a box-like preparation, retroplast (Gluma and resin) may be applied to a slightly concave root surface. It may therefore be employed in areas normally inaccessible with amalgam technique. Retroplast can thus be used on roots of all molars and to restore root perforations, root resorptions, cracks, grooves and defects of the root. In addition on lateral canals, on extremely thin roots and to cover perforating root canal posts, this technique can also be used. Dentin/root-cement transplantation may be performed for the purpose of reattachment. The article discusses the technique and its applications with examples showing that it may result in satisfactory healing. PMID:2696126

  16. Assessment of ion diffusion from a calcium hydroxide-propolis paste through dentin

    OpenAIRE

    Janaina Corazza Montero; Graziela Garrido Mori

    2012-01-01

    This study evaluated the ability of ions from a non-alcoholic calcium hydroxide-propolis paste to diffuse through dentinal tubules. Thirty-six single-rooted bovine teeth were used. The tooth crowns were removed, and the root canals were instrumented and divided into 3 groups: Group 1 - calcium hydroxide-propylene glycol paste; Group 2 - calcium hydroxide-saline solution paste; Group 3 - calcium hydroxide-propolis paste. After the root canal dressings were applied, the teeth were sealed and pl...

  17. Epitympanoplasty with Cartilage Obliteration in the Canal Wall Up Technique to the Middle Ear Cholesteatoma%保留外耳道后壁上鼓室切开软骨重建术治疗中耳胆脂瘤

    Institute of Scientific and Technical Information of China (English)

    赵丹珩; 刘阳; 孙建军; 林勇生

    2013-01-01

    Objective To report the curative effect of the epitympanoplasty with cartilage obliteration in the treatment of middle ear cholesteatoma .Methods This study retrospectively analysed 123 cases ,with middle ear cholesteatoma treated in our department from November 2009 to July 2012 .The operation included mastoidectomy with posterior canal wall preserved ,lateral wall of attic resected ,facial recess opened to the epitympanum ,epitym-panum obliterated with cartilage and mastoid cavity blocked with bone dust .All cases were followed up on complica-tions and hearing improvement .Results All cases were followed up 6~38 months .In 123 cases ,there were 2 ca-ses had cholesteatoma recurrence in the middle ear cavity ,6 cases had infection of post auricular incision after opera-tion ,3 cases had residual marginal tympanic membrane perforation ,2 cases had ossicular replacement prosthesis ex-clusion ,and 6 cases had canal wall skin swelling or defect .The rest cases acquired full -recovery after 2 or 3 wound dressing changes .Out of 123 cases ,83 cases had the whole hearing document ,the average AB gap at 0 .5 ,1 ,2 kHz reduced from 32 .2 ± 11 .2 dB pre-operation to 20 .7 ± 12 .4 dB post -operation .The AB gap of pre - and post -operation had significant difference (P<0 .001) .Conclusion The mastoidectomy with posterior canal wall preserved greatly shortened the healing time .The resection of lateral wall of epitympanum can exposed operating field more completely and remove lesions thoroughly .The cartilage obliteration in the attic can prevent the retraction pocket formation effectively .This technique provides alternative in treating middle ear cholesteatoma .%目的探讨在保持外耳道后壁完整的情况下,切除上鼓室外侧壁并软骨封闭治疗中耳胆脂瘤的疗效。方法2009年11月~2012年7月对123例(123耳)中耳胆脂瘤患者行保留外耳道后壁的乳突切开、上鼓室盾板切除及面神经隐窝向上鼓室开放,清除病

  18. 前壁外耳道-鼓膜瓣应用于开放式鼓室成形术31例%Application of anterior wall of external auditory canal ardrum flap for open tympanoplasty in 31 patients

    Institute of Scientific and Technical Information of China (English)

    陈泽; 钟兆棠; 梁敏志

    2014-01-01

    目的:探讨前壁外耳道-鼓膜瓣应用于开放式鼓室成形术中,能否提高鼓膜修补成功率和手术疗效。方法对慢性化脓性中耳炎及中耳胆脂瘤伴中、下鼓室自行封闭患者66例(66耳),予开放式鼓室成形术治疗,其中31例术中应用前壁外耳道-鼓膜瓣内植法鼓室成形(前瓣组),35例应用软骨和筋膜内植法鼓室成形(软骨组),测定术前及术后6个月气导(AC)、气骨导差(ABG),比较两组的临床疗效。结果前瓣组成功率为96.8%(30/31),软骨组88.6%(31/35),两组比较差异无统计学意义(P >0.05);前瓣组有效率为88.46%,软骨组为65.52%,两组比较差异有统计学意义(P <0.05),即前瓣组优于软骨组。结论伴有中、下鼓室封闭的慢性中耳炎患者,行开放式鼓室成形术中应用前壁外耳道-鼓膜瓣鼓室成形能提高筋膜成活率,术后鼓膜穿孔率低,较好成形鼓室,并能同期听力重建,提高听力。%Objective To investigate the application of anterior wall of external auditory canal-eardrum flap in open tympanoplasty to improve tympanic molding.Methods 66 patients (66 ears)with chronic suppurative otitis media or middle ear cholesteatoma accompanied with self sealing of mesotympanum and hypotympanum underwent open tympan-oplasty.31 cases were applied with anterior wall of external auditory meatus-eardrum flap (Anterior flap group)and 35 cases were treated with cartilage and fascia inner-transplanted method (Cartilage group).Air conduction (AC)and air bone gap (ABG)were performed six months before and after surgery.The clinical effect of the two groups were Com-pared.Results The success rates were 96.8%(30 /31)and 88.6%(31 /35)in anterior flap group and cartilage group respectively (P >0.05 ),while the effective rates were 88.46% and 65.52% correspondingly in the two groups (P <0.05).Conclusion For the patients

  19. Adaptation and penetration of resin-based root canal sealers in root canals irradiated with high-intensity lasers

    Science.gov (United States)

    Moura-Netto, Cacio; Mello-Moura, Anna Carolina Volpi; Palo, Renato Miotto; Prokopowitsch, Igor; Pameijer, Cornelis H.; Marques, Marcia Martins

    2015-03-01

    This research analyzed the quality of resin-based sealer adaptation after intracanal laser irradiation. Extracted teeth (n=168) were root canal treated and divided into four groups, according to dentin surface treatment: no laser; Nd:YAG laser (1.5 W, 100 mJ, 15 Hz) diode laser (2.5 W in CW), and Er:YAG laser (1 W, 100 mJ, 10 Hz). The teeth were divided into four subgroups according to the sealer used: AH Plus, EndoREZ, Epiphany, and EpiphanySE. For testing the sealing after root canal obturation, the penetration of silver nitrate solution was measured, whereas to evaluate the adaptation and penetration of the sealer into the dentin, environmental scanning electron microscopy (ESEM) was used. The ESEM images were analyzed using a four-grade criteria score by three evaluators. The inter-examiner agreement was confirmed by Kappa test and the scores statistically compared by the Kruskal-Wallis' test (proot canals were not affected by the laser irradiation. Nd:YAG and diode laser decreased the tracer penetration for AH Plus, whereas EndoREZ and EpiphanySE performances were affected by Nd:YAG irradiation (proot canals were irradiated with Nd:YAG laser.

  20. Application of microcomputed tomography for quantitative analysis of dental root canal obturations

    Directory of Open Access Journals (Sweden)

    Małgorzata Jaworska

    2014-03-01

    Full Text Available Introduction: The aim of the study was to apply microcomputed tomography to quantitative evaluation of voids and to test any specific location of voids in tooth’s root canal obturations. Materials and Methods: Twenty root canals were prepared and obturated with gutta-percha and Tubli-Seal sealer using the thermoplastic compaction method (System B + Obtura II. Roots were scanned and three-dimensional visualization was obtained. The volume and Feret’s diameter of I-voids (at the filling/dentine interface and S-voids (surrounded by filling material were measured. Results: The results revealed that none of the scanned root canal fillings were void-free. For I-voids, the volume fraction was significantly larger, but their number was lower (P = 0.0007, than for S-voids. Both types of voids occurred in characteristic regions (P < 0.001. I-voids occurred mainly in the apical third, while S-voids in the coronal third of the canal filling. Conclusions: Within the limitations of this study, our results indicate that microtomography, with proposed semi-automatic algorithm, is a useful tools for three-dimensional quantitative evaluation of dental root canal fillings. In canals filled with thermoplastic gutta-percha and Tubli-Seal, voids at the interface between the filling and canal dentine deserve special attention due to of their periapical location, which might promote apical microleakage. Further studies might help to elucidate the clinical relevance of these results.

  1. Rootless teeth: Dentin dysplasia type I

    Directory of Open Access Journals (Sweden)

    Sangamesh G Fulari

    2013-01-01

    Full Text Available A rare case of hereditary disturbance of dentine, Dentin dysplasia type I is presented, which is characterized by short or total absence of roots, obliterated pulp chambers, and peri-apical radiolucencies. It affects both primary and secondary dentition. Management of patients with dentinal dysplasia is difficult and requires a multidisciplinary approach. An overview of dentin dysplasia and its management along with a case report is discussed.

  2. Penetration of amalgam constituents into dentine

    OpenAIRE

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

    2009-01-01

    OBJECTIVES: Amalgam restorations are replaced by adhesively placed composite resin restorations at an increasing rate. After the removal of amalgam dentine often shows marked dark discoloration that is attributed to the penetration of corrosion products from overlying amalgams. It is questioned whether penetration of metals into dentine affects the dentine as a substrate for adhesive procedures. This study has been performed to clarify the origin of dark discoloration of dentine by metals fro...

  3. Effect of chloroform, eucalyptol and orange oil solvents on the microhardness of human root dentin.

    Directory of Open Access Journals (Sweden)

    Sedigheh Khedmat

    2015-02-01

    Full Text Available This study aimed to assess the effect of chloroform, eucalyptol and orange oil solvents on the microhardness of human root dentin.Sixty-eight single-rooted single-canal extracted human premolar teeth were used. Tooth crowns were separated from the roots at the cementoenamel junction (CEJ. Roots were buccolingually sectioned into mesial and distal halves. Specimens were randomly divided into 5 groups, with 20 teeth in each solvent group and 4 teeth in each control group. Primary microhardness of specimens was measured using Vickers microhardness tester. Specimens were exposed to solvents for 15 minutes and were subjected to microhardness testing again. Data were recorded and analyzed using repeated measure ANOVA.No significant difference was found in dentin microhardness before and after exposure to solvents in any of the orange oil, eucalyptol, chloroform or saline groups (P=0.727. None of the experimental groups showed any significant difference in terms of dentin microhardness reduction (P=0.99 and had no significant difference with the negative control group.This study showed that chloroform, eucalyptol and orange oil as gutta percha solvents did not decrease the microhardness of root dentin. Thus, none of the mentioned solvents has any superiority over the others in terms of affecting dentin properties.

  4. 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.

  5. Comparison the Effects of Different Root Canal Irrigants on the Retention of Quarts Fiber Posts Cemented by Resin Cement

    OpenAIRE

    Mehdi Shirinzad; Zahed Mohammadi; Loghman Rezaei-Soufi; Mehdi Rasekh

    2012-01-01

    Introduction: Root canal irrigants could change the structure of root dentin and affect the posts retention the purpose of this study was to compare the effects of three different endodontic irrigants on the retention of quarts fiber posts cemented by different resin cements. Materials & Methods: In this in-vitro study, 10 mm long post spaces were prepared in root canals of 120 premolars after endodontic therapy and cutting the crowns at the cementoenamel junction. The teeth were randomly div...

  6. The effect of electropolishing on torque and force during simulated root canal preparation with ProTaper shaping files

    OpenAIRE

    Boessler, C; Paqué, F; Peters, O A

    2009-01-01

    Surface modifications of nickel-titanium instruments such as electropolishing may reduce fracture incidence but could potentially alter the instruments' mechanical properties. We studied the impact of two surface types, machined and electropolished, of ProTaper shaping files on torque and force during simulated root canal preparation. Pilot holes of 0.5-mm diameter were drilled perpendicularly through 3-mm thick human dentin discs and served as standardized simulated root canals (SSRCs). A to...

  7. 开放式鼓室成形听力重建术不同频率效果分析%Frequency-specific hearing assessment after canal wall-down tympanoplasty for chronic ear diseases

    Institute of Scientific and Technical Information of China (English)

    陶朵朵; 陈兵

    2012-01-01

    Objectives To analyze frequency-specific hearing results after canal wall-down tympanoplasty for chronic ear diseases, in relation to various surgical factors. Methods Patients who underwent canal wall-down tympanoplasty for chronic ear diseases from June 2008 to January 2011 in the Department of Otolaryngology, Eye Ear Nose & Throat Hospital, Fudan University were reviewed retrospectively (n=87). Using pure tone audiometry, air-conductive threshold (AC), bone-conductive threshold (BC) ,and air-bone gap (ABG), and pre- and post-operative changes were analyzed for each of the following frequencies: 0.25 kHz, 0.5 kHz, 1 kHz, 2 kHz, 3 kHz, 4 kHz (AC and BC) and 6 kHz (AC). Frequency-specific results were investigated in relation to various surgical factors. Results Both AC and ABC results showed improvements at each frequency, primarily in the low and mid frequencies. The improvement decreased gradually from low to high frequencies. BC results showed significant improvement at every frequency except 4 kHz. In patients without ossiculoplasty, BC results improved significantly only at 1 kHz. Conclusion Canal wall-down tympanoplasty for chronic ear diseases can improve hearing primarily in low and mid frequencies.%目的 探讨慢性中耳炎患者开放式鼓室成形术后听力重建效果,并对不同频率听力重建效果进行对比分析.方法 回顾2008年6月至2011年1月在复旦大学附属眼耳鼻喉科医院耳鼻喉科行开放式鼓室成形术的920例患者,从中筛选具有完整随访资料患者87名,利用纯音测听对患者手术前后0.25 kHz、0.5 kHz、1 kHz、2kHz、3 kHz、4kHz、6 kHz频率处的纯音气导听阈、骨导听阈和气骨导差进行评估,比较各项指标手术前后差异,探讨各频率重建效果的可能影响因素.结果 术后气导听阈总体平均值在各个频率均有显著改善,听觉重建效果从低频到高频呈下降趋势,其中1 kHz以下频率明显优于2 kHz以上频率;术后气骨导

  8. Root canal filling evaluation using optical coherence tomography

    Science.gov (United States)

    Negrutiu, Meda L.; Sinescu, Cosmin; Topala, Florin; Nica, Luminita; Ionita, Ciprian; Marcauteanu, Corina; Goguta, Luciana; Bradu, Adrian; Dobre, George; Rominu, Mihai; Podoleanu, Adrian Gh.

    2010-04-01

    Endodontic therapy consists in cleaning and shaping the root canal system, removing organic debris and sealing the intra-canal space with permanent filling materials. The purpose of this study was to evaluate various root canal fillings in order to detect material defects, the marginal adaptation at the root canal walls and to assess the quality of the apical sealing. 21 extracted single-root canal human teeth were selected for this study. We instrumented all roots using NiTi rotary instruments. All canals were enlarged with a 6% taper size 30 GT instrument, 0,5 mm from the anatomical apex. The root canals were irrigated with 5% sodium hypochlorite, followed by 17% ethylenediaminetetraacetic acid (EDTA). After the instrumentation was completed, the root canals were obturated using a thermoplasticizable polymer of polyesters. In order to assess the defects inside the filling material and the marginal fit to the root canal walls, the conebeam micro-computed tomography (CBμCT) was used first. After the CBμCT investigation, time domain optical coherence tomography working in en face mode (TDefOCT) was employed to evaluate the previous samples. The TDefOCT system was working at 1300 nm and was doubled by a confocal channel at 970 nm. The results obtained by CBμCT revealed no visible defects inside the root-canal fillings and at the interfaces with the root-canal walls. TDefOCT investigations permit to visualize a more complex stratificated structure at the interface filling material/dental hard tissue and in the apical region.

  9. Dentin hypersensitivity and its management.

    Science.gov (United States)

    Chu, C H; Lam, Anty; Lo, Edward C M

    2011-01-01

    Dentin hypersensitivity is a common patient complaint that is more prevalent than the profession realizes. It is important for dentists to diagnose dentin hypersensitivity by exclusion and provide appropriate treatment recommendations for patients. Various treatment methods have been proposed but no universally accepted desensitizing agent or treatment has been identified. When a patient has symptoms that can be attributed to dentin hypersensitivity, a thorough clinical examination should be carried out to rule out other likely causes prior to diagnosis and treatment. Depending on the identified cause, a combination of individualized instructions on proper oral health behaviors, use of at-home products, and professional treatment may be required to manage the problem. PMID:21903521

  10. Effect of irrigation technique for removal of triple antibiotic paste on bond strength of MTA to root dentin.

    Science.gov (United States)

    Dumani, Aysin; Yilmaz, Sehnaz; Yoldas, Oguz; Bek, Zeliha Gonca

    2016-01-01

    This study evaluated the bond strength of mineral trioxide aggregate (MTA) to root canal dentin after the performance of various irrigation procedures to remove triple antibiotic paste (TAP). A total of 56 single-rooted human mandibular premolars were instrumented using a rotary system to size 40 and divided randomly into a control group (no intracanal dressing) and three experimental groups (TAP application for 28 days). TAP was then removed by rinsing with 10 mL 2.5% NaOCl using three irrigation systems (Vibringe sonic irrigation, CanalBrush, and syringe irrigation). The coronal and middle parts of root canals were then obturated with MTA. After storage for 1 week, each specimen was embedded in an acrylic block and sectioned horizontally (2-mm-thick slices) at two levels (coronal and middle). Bond strength of MTA to root canal dentin was assessed in 28 samples per group via push-out test using a universal testing machine. Data from the four groups were compared using one-way analysis of variance. Tukey's test was used for multiple comparisons. Push-out bond strength values were significantly higher in the control and Vibringe groups than in the CanalBrush and syringe irrigation groups (p irrigation system may increase the push-out bond strength of MTA compared with the use of the CanalBrush or syringe irrigation. PMID:27191739

  11. Effect of irrigation technique for removal of triple antibiotic paste on bond strength of MTA to root dentin.

    Science.gov (United States)

    Dumani, Aysin; Yilmaz, Sehnaz; Yoldas, Oguz; Bek, Zeliha Gonca

    2016-01-01

    This study evaluated the bond strength of mineral trioxide aggregate (MTA) to root canal dentin after the performance of various irrigation procedures to remove triple antibiotic paste (TAP). A total of 56 single-rooted human mandibular premolars were instrumented using a rotary system to size 40 and divided randomly into a control group (no intracanal dressing) and three experimental groups (TAP application for 28 days). TAP was then removed by rinsing with 10 mL 2.5% NaOCl using three irrigation systems (Vibringe sonic irrigation, CanalBrush, and syringe irrigation). The coronal and middle parts of root canals were then obturated with MTA. After storage for 1 week, each specimen was embedded in an acrylic block and sectioned horizontally (2-mm-thick slices) at two levels (coronal and middle). Bond strength of MTA to root canal dentin was assessed in 28 samples per group via push-out test using a universal testing machine. Data from the four groups were compared using one-way analysis of variance. Tukey's test was used for multiple comparisons. Push-out bond strength values were significantly higher in the control and Vibringe groups than in the CanalBrush and syringe irrigation groups (p irrigation system may increase the push-out bond strength of MTA compared with the use of the CanalBrush or syringe irrigation.

  12. Assessment of the bacteria reduction in the infected root canal irradiated with diode laser; Avaliacao da reducao bacteriana em conduto radicular infectado e irradiado com laser de diodo. Estudo in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Radaelli, Claudia Amaral Rabello de Mello

    2002-07-01

    the periapical point which width measured 1 mm, approximately. The maximum temperature variation was 7.45 deg C. Under electron microscope scanning, the control groups showed areas with smear layer covering the dentinal walls. The laser irradiated groups showed a smooth, uniform, clean appearance, with small areas of closed dentinal tubules without cracking alternately with areas of exposed open dentinal tubules. Some parts showed fusion of the dentinal mass (groups irradiated with 3 W). In groups where calcium hydroxide was associated with laser irradiation remains were found over the irradiated surface and, in many parts, the dentinal tubules could not be observed. The use of high intensity diode laser at 830 nm proved to be efficient and able to promote reduction in the Enterococcus faecalis population in the infected root canals. (author)

  13. A radiographic study of mandibular canal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Chul; Lee, Sang Rae [Dept. of Oral Radiology, Division of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    1987-11-15

    The author invested the gonial angle, the angle of mandibular and mental canal to the lower border of the mandible, and a relationship of the position of the mandibular canal to the root apex of the posterior teeth and the cortical plate of the lower of the mandible. The materials consisted of 458 pantomograms in male and female aged 11-40 and divided into 5 groups at year intervals and subdivided into 3 groups by gonial angle. The results were as follows: 1. The gonial angle decreased with age, but slight increase occurred over 26-30 years. 2. The average angle of the mandibular canal to the lower border of the mandible was 151.6 degree and did not correlate with age. 3. The average angle of the mental canal to the lower border of the mandible was 36.9 degree and didn't correlate with age. 4. The angles of mandibular and mental canal to the lower border of mandible correlated with gonial angle. 5. The distance from the root apex of the posterior teeth to the upper wall mandibular canal was most short at the region of the distal root of the mandibular second and increased with age at the region of the mandibular second molar. 6. The distance from the lower wall of the mandibular canal to the cortical plate of the lower border of the mandibule was most short at the region of the mesial root of the mandibular first molar and didn't correlate with age.

  14. Femtosecond laser ablation of dentin

    International Nuclear Information System (INIS)

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

  15. Comparison of two sonic handpieces during the preparation of simulated root canals.

    Science.gov (United States)

    Dummer, P M; Hutchings, R; Hartles, F R

    1993-05-01

    The objective of this study was to assess and compare two sonic handpieces during the preparation of simulated root canals. A total of 60 simulated canals in clear resin blocks of various angles and positions of curvature were prepared using Shaper files activated either by an MM1500 Sonic Air or an MM1400 Mecasonic handpiece. Each handpiece was used to prepare 30 canals using an identical preparation procedure which involved a linear filing motion and an anticurvature technique in curved canals. The efficacy of the handpieces was determined for straight and curved canals separately and included an assessment of loss of canal length, weight loss from the blocks, smoothness of canal walls, transportation and overall shape of the prepared canals. Canals were prepared rapidly and effectively by both handpieces. Overall, the MM1500 handpiece was associated with significantly less distance loss (P canals (8%) had hour-glass shapes displaying zips and elbows, each handpiece created two. Only two canals (4%) had danger zones, both were created by the MM1400 handpiece. There was little difference between the handpieces in terms of the smoothness of canal walls, the direction and amount of transportation or the overall shape of canals. Under the conditions of this study, the new MM1400 Mecasonic handpiece performed as well as the established MM1500 Sonic Air. PMID:8406963

  16. The fluid mechanics of root canal irrigation.

    Science.gov (United States)

    Gulabivala, K; Ng, Y-L; Gilbertson, M; Eames, I

    2010-12-01

    Root canal treatment is a common dental operation aimed at removing the contents of the geometrically complex canal chambers within teeth; its purpose is to remove diseased or infected tissue. The complex chamber is first enlarged and shaped by instruments to a size sufficient to deliver antibacterial fluids. These irrigants help to dissolve dying tissue, disinfect the canal walls and space and flush out debris. The effectiveness of the procedure is limited by access to the canal terminus. Endodontic research is focused on finding the instruments and clinical procedures that might improve success rates by more effectively reaching the apical anatomy. The individual factors affecting treatment outcome have not been unequivocally deciphered, partly because of the difficulty in isolating them and in making the link between simplified, general experimental models and the complex biological objects that are teeth. Explicitly considering the physical processes within the root canal can contribute to the resolution of these problems. The central problem is one of fluid motion in a confined geometry, which makes the dispersion and mixing of irrigant more difficult because of the absence of turbulence over much of the canal volume. The effects of treatments can be understood through the use of scale models, mathematical modelling and numerical computations. A particular concern in treatment is that caustic irrigant may penetrate beyond the root canal, causing chemical damage to the jawbone. In fact, a stagnation plane exists beyond the needle tip, which the irrigant cannot penetrate. The goal is therefore to shift the stagnation plane apically to be coincident with the canal terminus without extending beyond it. Needle design may solve some of the problems but the best design for irrigant penetration conflicts with that for optimal removal of the bacterial biofilm from the canal wall. Both irrigant penetration and biofilm removal may be improved through canal fluid

  17. The fluid mechanics of root canal irrigation

    International Nuclear Information System (INIS)

    Root canal treatment is a common dental operation aimed at removing the contents of the geometrically complex canal chambers within teeth; its purpose is to remove diseased or infected tissue. The complex chamber is first enlarged and shaped by instruments to a size sufficient to deliver antibacterial fluids. These irrigants help to dissolve dying tissue, disinfect the canal walls and space and flush out debris. The effectiveness of the procedure is limited by access to the canal terminus. Endodontic research is focused on finding the instruments and clinical procedures that might improve success rates by more effectively reaching the apical anatomy. The individual factors affecting treatment outcome have not been unequivocally deciphered, partly because of the difficulty in isolating them and in making the link between simplified, general experimental models and the complex biological objects that are teeth. Explicitly considering the physical processes within the root canal can contribute to the resolution of these problems. The central problem is one of fluid motion in a confined geometry, which makes the dispersion and mixing of irrigant more difficult because of the absence of turbulence over much of the canal volume. The effects of treatments can be understood through the use of scale models, mathematical modelling and numerical computations. A particular concern in treatment is that caustic irrigant may penetrate beyond the root canal, causing chemical damage to the jawbone. In fact, a stagnation plane exists beyond the needle tip, which the irrigant cannot penetrate. The goal is therefore to shift the stagnation plane apically to be coincident with the canal terminus without extending beyond it. Needle design may solve some of the problems but the best design for irrigant penetration conflicts with that for optimal removal of the bacterial biofilm from the canal wall. Both irrigant penetration and biofilm removal may be improved through canal fluid

  18. Root canal irrigants

    Directory of Open Access Journals (Sweden)

    Kandaswamy Deivanayagam

    2010-01-01

    Full Text Available Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ′root canal irrigants′ and ′endodontic irrigants.′ The reference lists of each article were manually checked for additional articles of relevance.

  19. 完壁式鼓室成形术治疗慢性化脓性中耳炎%Intact Canal Wall Tympanoplasty in Treating Patients with Chronic Suppurative Otitis Media

    Institute of Scientific and Technical Information of China (English)

    王凯; 俞杰; 李幼珍; 张建

    2013-01-01

    目的:介绍完壁式鼓室成形术治疗慢性化脓性中耳炎的的手术体会。方法回顾性分析96完壁式鼓室成形术治疗慢性化脓性中耳炎的临床资料,术中注意上鼓室外侧壁盾板的完整,清除病灶保护粘膜,建立咽鼓管、鼓室、鼓窦、乳突的通气引流系统。结果术前纯音听力测试0.5、1.0、2.0、4.0kHz语言频率区听阈气骨导差的平均值0-10dB为0耳(0%),11-20 dB为4耳(4.17%),21-30 dB为29耳(30.2%),31-40 dB为46耳(47.9%),大于40 dB为17耳(17.7%),平均气导为(54.1±6.5)dB,平均骨导为(13.6±7.6)dB;术后3月纯音听力测试,0.5、1.0、2.0、4.0kHz语言频率区听阈气骨导差的平均值0-10dB为25耳(26.0%),11-20 dB为46耳(47.9%),21-30 dB为19耳(19.8%),31-40 dB为6耳(6.3%),大于40 dB为0耳0%),平均气导为(38.1.±7.9)dB,平均骨导为(12.5±6.3)dB。术后8月以上(平均间隔时间为11个月)纯音听力测试的情况是0-10dB为22耳(22.9%),11-20 dB为41耳(42.7%),21-30 dB为24耳(25%),31-40 dB为9耳(9.3%),大于40 dB为0耳0%),平均气导为(41.2±8.4)dB,平均骨导为(12.6±7.6)dB。术后8个月~3年随访中行颞骨CT扫描(平均间隔时间为11个月),96耳中75耳乳突鼓窦保持气化(78.1%),21耳乳突鼓窦软组织影充填(21.9%)。结论完壁式鼓室成形术治疗慢性化脓性中耳炎可取得满意疗效,遵循个体化原则建立合理的中耳通气引流系统是手术的关键。%Objective To introduce the experience of the intact canal wall tympanoplasty in chronic suppurative otitis media. Methods Clinical data of 96 cases of the intact canal wall tympanoplasty for treating chronic suppurative otitis media was retrospectively reviewed. During the operation, the outside wall of attic should be keeped intact, lesions should be re-moved, mucosa

  20. A quantitative analysis of rotary, ultrasonic and manual techniques to treat proximally flattened root canals

    Directory of Open Access Journals (Sweden)

    Fabiana Soares Grecca

    2007-04-01

    Full Text Available OBJECTIVE: The efficiency of rotary, manual and ultrasonic root canal instrumentation techniques was investigated in proximally flattened root canals. MATERIAL AND METHODS: Forty human mandibular left and right central incisors, lateral incisors and premolars were used. The pulp tissue was removed and the root canals were filled with red die. Teeth were instrumented using three techniques: (i K3 and ProTaper rotary systems; (ii ultrasonic crown-down technique; and (iii progressive manual technique. Roots were bisected longitudinally in a buccolingual direction. The instrumented canal walls were digitally captured and the images obtained were analyzed using the Sigma Scan software. Canal walls were evaluated for total canal wall area versus non-instrumented area on which dye remained. RESULTS: No statistically significant difference was found between the instrumentation techniques studied (p<0.05. CONCLUSION: The findings of this study showed that no instrumentation technique was 100% efficient to remove the dye.

  1. Status of bacterial colonization in infected root canal%感染根管内细菌定植状态的观察

    Institute of Scientific and Technical Information of China (English)

    郭惠杰; 岳林; 高岩

    2011-01-01

    bacteria in the root canals using a scanning electron microscope. Results: Histobacteriologic observation showed that bacteria were found in all the seven specimens, which were clogged with a dense bacterial biofilm in the apical third of the main canal. Bacteria could penetrate into the dentinal tubules about 140 - 1 000 μm. Scanning electron microscopy observation showed that bacteria consisting of cocci, rods and/or filaments with amorphous materials formed the typical biofilm structure in the apical third of the root canals. Conclusion : The findings support the view that bacteria colonizing the root canal system play an essential role in the pathogenesis of periradicular diseases. In all the seven specimens, bacteria usually formed dense aggregates on the root canal walls, penetrating the dentinal tubules in the apical third of the main canal. Dense bacteria and amorphous materials filled the inter-bacterial spaces and formed the typical biofilm structure.

  2. Effect of pressure upon wall-to-wall polymerization contraction of a chemically-cured resin.

    Science.gov (United States)

    Hansen, E K

    1983-02-01

    The marginal gaps of 105 Silar fillings were measured after application of a load between zero and 100 N on the matrix during the initial polymerization. The fillings were placed in non-etched dentin cavities in extracted human teeth. The dentin surrounding the cavities was either roughened with carborundum paper No. 220 or polished with Alfa Micropolish 1 micron before the cavities were filled. When load was applied to the matrix, no effect was found of the roughness surrounding the cavities, but without load the wall-to-wall contraction was significantly greater in cavities where the surrounding dentin surfaces had been polished with Alfa Micropolish. Apparently the effect of load was related to friction during the polymerization between filling surplus and the dentin surrounding the cavities and not to load per se.

  3. Influence of endodontic sealer composition and time of fiber post cementation on sealer adhesiveness to bovine root dentin.

    Science.gov (United States)

    Rosa, Ricardo Abreu da; Barreto, Mirela Sangoi; Moraes, Rafael do Amaral; Broch, Juliana; Bier, Carlos Alexandre Souza; Só, Marcus Vinícius Reis; Kaizer, Osvaldo Bazzan; Valandro, Luiz Felipe

    2013-01-01

    This study aimed to assess the influence of the type of endodontic sealer (salicylate resin-based sealer vs. two endodontic sealers) and the time of fiber post cementation after root filling on the post adhesion to bovine root dentin. Sixty bovine roots were assigned to six groups (n=10), considering an experimental design with two factors (factorial 3x2): endodontic sealer factor in three levels [epoxy resin-based sealer (AH Plus), eugenol-based sealer (Endofill), and salicylate resin-based sealer plus mineral trioxide aggregate - MTA (MTA Fillapex)] and time for post cementation factor in two levels (immediate post cementation or 15 days after root canal filling). After post cementation, 2-mm-thick slices were produced and submitted to push-out test. The failure modes were analyzed under a 40× stereomicroscope and scored as: adhesive at cement/dentin interface; adhesive at cement/post interface; cement cohesive; post cohesive; dentin cohesive; or mixed. Data were analyzed using two-way ANOVA and Tukey's post-hoc tests (α=0.05). When the fiber posts were cemented immediately after the root canal filling, the bond strengths were similar, independent of the endodontic sealer type. However, after 15 days, the epoxy resin-based sealer presented higher bond strength than the other sealers (pcement interface (89.4%). The time elapsed between the root canal filling and post cementation has no influence on post/root dentin adhesion. On the contrary, the type of endodontic sealer can influence the adhesion between fiber posts and root dentin. PMID:23969913

  4. Is bovine dentine an appropriate substitute for human dentine in erosion/abrasion tests?

    OpenAIRE

    Wegehaupt, F; Gries, D.; A. Wiegand; Attin, T.

    2008-01-01

    The study aimed to compare the dentine wear of primary and permanent human and bovine teeth because of erosion/abrasion and evaluate if bovine dentine is an appropriate substitute for human dentine in further erosion/abrasions tests. Dentine samples from deciduous molars and human third molars as well as from calves' and cattle's lower incisors were prepared and baseline surface profiles were recorded. Each day all samples were demineralized in 1% citric acid, tooth brushed with 100 brushing ...

  5. Application of a proanthocyanidin agent to improve the bond strength of root dentin treated with sodium hypochlorite

    Directory of Open Access Journals (Sweden)

    V Sujatha Manimaran

    2011-01-01

    Full Text Available Aim: The objective of this study was to analyze the application of PA agent that improves the bond strength of root dentin treated with NaOCl. Materials and Methods: Group 1: root canals were irrigated using 0.9% isotonic saline as an irrigant (negative control; Group 2: root canals were irrigated using 5.25% NaOCl (positive control; Group 3: root canals were irrigated with 5.25% NaOCl followed by 10% sodium ascorbate for 10 minutes; Group 4: root canals were irrigated with 5.25% NaOCl followed by 5% PA for 10 minutes. All the canals were then coated with self-etch dentin bonding agent, filled with resin cement, stored for one day in water, and then cross sectioned into three slabs of 2-mm thickness that were prepared and tested for microtensile bond strength. Results: The results demonstrated that 5.25% NaOCl caused significant reduction (P<0.05 in the bond strength, but this can be reversed by 5% PA significantly more than the 10% sodium ascorbate.

  6. COHESIVE STRENGTH OF DENTIN RESISTÊNCIA COESIVA DA DENTINA

    OpenAIRE

    DEMARCO, Flávio Fernando; Turbino, Miriam Lacalle; Edmir MATSON

    1997-01-01

    The bond strength of dentin adhesives to dentin has increased after each generation. Although dentin substratum is part of the bonding process, little importance has been given to measure dentin cohesive strength. The aim of this study was to evaluate the cohesive strength of dentin in human canines. Seventeen non carious canines were selected. All of them had been extracted for more than one year. The teeth were ground until dentin square samples with approximately 2 X 2 mm were obtained. Th...

  7. 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.

  8. 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

  9. Dielectric response of the human tooth dentine

    Energy Technology Data Exchange (ETDEWEB)

    Leskovec, J. [Dental Clinic, Faculty of Medicine, University of Ljubljana, Hrvatski trg 6, 1104 Ljubljana (Slovenia); Filipic, C. [Jozef Stefan Institute, P.O. Box 3000, 1001 Ljubljana (Slovenia); Levstik, A. [Jozef Stefan Institute, P.O. Box 3000, 1001 Ljubljana (Slovenia)]. E-mail: adrijan.levstik@ijs.si

    2005-07-15

    Dielectric properties of tooth dentine can be well described by the model which was developed for the dielectric response to hydrating porous cement paste. It is shown that the normalized dielectric constant and the normalized specific conductivity are proportional to the model parameters -bar {sub v0} and {sigma}{sub v}, indicating the deposition of AgCl in the dentine tubules during the duration of the precipitation. The fractal dimension of the tooth dentine was determined by dielectric spectroscopy.

  10. Dielectric response of the human tooth dentine

    International Nuclear Information System (INIS)

    Dielectric properties of tooth dentine can be well described by the model which was developed for the dielectric response to hydrating porous cement paste. It is shown that the normalized dielectric constant and the normalized specific conductivity are proportional to the model parameters -bar v0 and σv, indicating the deposition of AgCl in the dentine tubules during the duration of the precipitation. The fractal dimension of the tooth dentine was determined by dielectric spectroscopy

  11. 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...

  12. Effects of human vascular endothelial growth factor on reparative dentin formation.

    Science.gov (United States)

    Zhang, Juan; Liu, Xia; Yu, Weixian; Zhang, Yingli; Shi, Ce; Ni, Shilei; Liu, Qilin; Li, Xiangwei; Sun, Yingjian; Zheng, Changyu; Sun, Hongchen

    2016-01-01

    It is a challenge for dentists to save dental pulp in patients with pulp disease without resorting to root canal therapy. Formation of tertiary dentin to maintain pulp vitality is a key odontoblast response to dental pulp injury. Vascular endothelial growth factor (VEGF) is the most potent angiogenic and vasculogenic factor involved in tertiary dentin formation. It was hypothesized that VEGF may be used to treat pulp diseases such as pulpitis. To explore this hypothesis, the first step was to assess whether VEGF affects dental pulp cells to promote reparative dentin formation. In the current study, an AdCMV‑hVEGF vector was constructed to deliver hVEGF into dental pulp cells of exfoliated deciduous teeth (hDPCs) in vitro and dental pulp cells in a rat model in vivo. The collected data clearly demonstrated that hVEGF increased alkaline phosphatase and mineralization by enzymatic activity. RT‑qPCR data demonstrated that hVEGF significantly increased the expression levels of genes commonly involved in osteogenesis/odontogenesis. Data from the in vivo assays indicated that hVEGF enhanced pulp cell proliferation and neovascularization, and markedly increased formation of reparative dentin in dental pulp. The in vitro and in vivo data suggest that hVEGF may have potential clinical applications, thus may aid in the development of novel treatment strategies for dental pulpitis. PMID:26647730

  13. 3D root canal modeling for advanced endodontic treatment

    Science.gov (United States)

    Hong, Shane Y.; Dong, Janet

    2002-06-01

    More than 14 million teeth receive endodontic (root canal) treatment annually. Before a clinician's inspection and diagnosis, destructive access preparation by removing teeth crown and dentin is usually needed. This paper presents a non-invasive method for accessing internal tooth geometry by building 3-D tooth model from 2-D radiographic and endoscopic images to be used for an automatic prescription system of computer-aided treatment procedure planning, and for the root canal preparation by an intelligent micro drilling machine with on-line monitoring. It covers the techniques specific for dental application in the radiographic images acquirement, image enhancement, image segmentation and feature recognition, distance measurement and calibration, merging 2D image into 3D mathematical model representation and display. Included also are the methods to form references for irregular teeth geometry and to do accurately measurement with self-calibration.

  14. Ex Vivo Evaluation of the Root Form and Root Canal Morphology of the Mandibular First Molar Using CBCT Technology

    Directory of Open Access Journals (Sweden)

    Narges Farhad-Mollashahi

    2014-07-01

    Full Text Available Background: This study aims to evaluate the root canal system and its curvature and the relationship between the root concavity and the dentin thickness of danger zone in the mandibular first molar using the cone beam CT method. Materials and Methods: A sum of 101 fresh extracted mandibular first molar were gathered and scanned by CBCT (planmeca romexis 3D machine. The root canal configuration was evaluated according to Vertucci’s classification. Then, the canal curvature was evaluated according to schneider's method in clinical and proximal views. Finally, the relationship between the root concavity and the dentin thickness of danger zone was evaluated using the Pearson correlation coefficient. Results: The most common canal configuration of the mesial roots was vertucci type IV (49.5%, followed by type II (46.5%. Root canal configuration of the distal root revealed type I in 50.5% and type II in 29.7%. The average angles in proximal dimension for MB, ML, DB and DL canals were 18.80, 18.77, 8.22 and 16.86, respectively. These values in clinical dimension were 22.50, 21.90, 13.83 and 12.04, respectively. No meaningful relationship was found between the dentin thickness and the root concavity of danger zone. Conclusion: The clinician's awareness of the anatomy of the root canal system and the canal curvatures and the internal and external anatomy of the root is helpful and necessary in diagnosis and treatment of the endodontic cases.

  15. EPR properties of intact and deproteinated dentin

    International Nuclear Information System (INIS)

    The effect of sample preparation on dentin electron paramagnetic resonance (EPR) spectra was investigated. The analysis was performed on dentin samples prepared by pure mechanical treatment or by an alkaline deproteination method. It was observed that (1) mechanical treatment induces both stable and transient signals, depending on the specific mechanical operation applied; and (2) sodium hydroxide deproteination removes the native signal, but at the same time introduces new confounding signals in the EPR spectrum. Also, it increases the radiation sensitivity of dentin. These findings suggest that attention must be paid to dentin sample preparation. (authors)

  16. Hereditary dentine disorders: dentinogenesis imperfecta and dentine dysplasia

    Directory of Open Access Journals (Sweden)

    MacKie Iain

    2008-11-01

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

  17. 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

  18. [The dentinal smear layer. Characteristics and interactions. 2].

    Science.gov (United States)

    Negri, P L; Eramo, S; Lotito, M; De Pino, C

    1991-03-15

    The Authors, after the presentation (in the first part of the Dossier) of a large literature review about the physical, chemical and clinical characteristics of formation, interaction, remotion of "smear layer" during cavity preparation in hard tooth tissue, describe the results of a scanning microelectronic research about the action as cleanser (for the dentinal cavity wall) of the CK101 (Caridex) versus wather, Tubulicid and phosphoric acid. The experimental results obtained "in vitro" show that the substance has relative action, without removing the tubular portion of "smear layer". PMID:2070916

  19. CT findings of the osteoma of the external auditory canal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ha Young; Song, Chang Joon; Yoon, Chung Dae; Park, Mi Hyun; Shin, Byung Seok [Chungnam National University, School of Medicine, Daejeon (Korea, Republic of)

    2006-07-15

    We wanted to report the CT image findings of the osteoma of the external auditory canal. Temporal bone CT scanning was performed on eight patients (4 males and 4 females aged between 8 and 41 years) with pathologically proven osteoma of the external auditory canal after operation, and the findings of the CT scanning were retrospectively reviewed. Not only did we analyze the size, shape, distribution and location of the osteomas, we also analyzed the relationship between the lesion and the tympanosqumaous or tympanomastoid suture line, and the changes seen on the CT scan images for the patients who were able to undergo follow-up. All the lesions of the osteoma of the external auditory canal were unilateral, solitary, pedunculated bony masses. In five patients, the osteomas occurred on the left side and for the other three patients, the osteomas occurred on the right side. The average size of the osteoma was 0.6 cm with the smallest being 0.5 cm and the largest being 1.2 cm. Each of the lesions was located at the osteochondral junction in the terminal part of the osseous external ear canal. The stalk of the osteoma of the external auditory canal was found to have occurred in the anteroinferior wall in five cases (63%), in the anterosuperior wall (the tympanosqumaous suture line) in two cases (25%), and in the anterior wall in one case. The osteoma of the external auditory canal was a compact form in five cases and it was a cancellous form in three cases. One case of the cancellous form was changed into a compact form 35 months later due to the advanced ossification. Osteoma of the external auditory canal developed in a unilateral and solitary fashion. The characteristic image findings show that it is attached to the external auditory canal by its stalk. Unlike our common knowledge about its occurrence, osteoma mostly occurred in the tympanic wall, and this is regardless of the tympanosquamous or tympanomastoid suture line.

  20. Design of canals

    CERN Document Server

    Swamee, P K

    2015-01-01

    The book presents firsthand material from the authors on design of hydraulic canals. The book discusses elements of design based on principles of hydraulic flow through canals. It covers optimization of design based on usage requirements and economic constraints. The book includes explicit design equations and design procedures along with design examples for varied cases. With its comprehensive coverage of the principles of hydraulic canal design, this book will prove useful to students, researchers, and practicing engineers. End-of-chapter pedagogical elements make it ideal for use in graduate courses on hydraulic structures offered by most civil engineering departments across the world.

  1. Metachronous tubulovillous and tubular adenomas of the anal canal

    OpenAIRE

    NOZAWA, HIROAKI; ISHIHARA, SOICHIRO; Morikawa, Teppei; Tanaka, Junichiro; YASUDA, KOJI; Ohtani, Kensuke; Nishikawa, Takeshi; Tanaka, Toshiaki; Kiyomatsu, Tomomichi; Kawai, Kazushige; Hata, Keisuke; Kazama, Shinsuke; Yamaguchi, Hironori; Sunami, Eiji; Kitayama, Joji

    2015-01-01

    Anal canal adenoma is an extremely rare disease that has the potential to transform into a malignant tumor. We herein presented a rare case of metachronous multiple adenomas of the anal canal. A 48-year-old woman underwent total colonoscopy following a positive fecal blood test. A 9-mm villous polyp arising from the posterior wall of the anal canal was removed by snare polypectomy. Histologically, the tumor was tubulovillous adenoma with high-grade dysplasia and the cut end was negative for t...

  2. The use of plastic models for teaching root canal cleansing and shaping

    OpenAIRE

    Eftekhar B

    2004-01-01

    The use of root canal models in endodontics education is of high importance. So, in this article"na new method is presented that the students can produce these models with simple and low cost"ninstruments."nThese plastic models are made of polyester which is low cost, available and has the approximate cutting"nproperties of dentin. The best molds were disposable syringes due to their low cost, availability and"nproducing smooth surfaces on polyester models. A spreader...

  3. Clinical application of titanium ossicular prostheses in intact canal wall tympanoplasty with mastoidectomy%钛质听骨在完壁式鼓室成形中的应用

    Institute of Scientific and Technical Information of China (English)

    仇弋戈; 何蓉; 陈永国; 麻宁; 郭欣

    2012-01-01

    目的:评价钛质听小骨假体在完壁式乳突根治鼓室成形术(ICWT)后的疗效.方法:对31例使用钛质听小骨假体进行ICWT的患者进行评估,按听骨类型分为部分听骨赝复物(PORP)组和全听骨赝复物(TORP)组,对2组患者术后1年的听力情况和并发症发生率进行分析.结果:手术总有效率为(气骨导差≤20 dB)87.1%,术后平均增益PROP组为(19.38±10.08)dB,TORP组为(15.15±10.15)dB;术后气骨导差PROP组为(12.29±4.40)dB,TORP组为(15.48±6.26)dB;2组术后气骨导差及气导增益表现均差异无统计学意义,但在低频区(0.5 kHz)气骨导差存在统计学差异;未见听骨排出发生.结论:钛质听小骨在ICWT能够取得满意的听力结果,成功率高于其他综合文献的报告.但2种类型听骨比较差异无统计学意义,术后并发症发生率低,有待长期的随访.%To evaluate the effects of intact canal wall tympanoplasty with mastoidectomy(ICWT) with titanium ossicular prostheses. Method: A retrospective review was performed on 31 patients who underwent ICWT from 2008 to 201L Patients' postoperative hearing results and complication rates were evaluated based on different types of ossicular prosthesis: partial ossicular replacement prosthesis(PORP) , total ossicular replacement prosthesis(TORP). Result:The total effectiveness was 87. 1%. No prosthesis was extruded. There was no significant difference in postoperative hearing results (average postoperative gain and ABG) between the two prostheses. In the low frequency(0. 5 kHz), singnificant difference in ABG was found. Conclusion: No significant difference in postoperative hearing results was found between PORP and TORP, which could be useful materials for tympanoplasty and obviously improve the hearing of otitis media patients after operation. As for the low incidence of postoperative complications in our short-term study Jong-term follow-up visit is necessary.

  4. Scanning electron microscopy and thermal characteristics of dentin ablated by a short-pulse XeCl excimer laser.

    Science.gov (United States)

    Neev, J; Stabholtz, A; Liaw, L H; Torabinejad, M; Fujishige, J T; Ho, P D; Berns, M W

    1993-01-01

    The interaction of a short pulse XeCl excimer laser radiation with human dentin was investigated. The dependence of surface temperatures and temperature gradients into the treated teeth on laser parameters such as fluence (0.5J/cm2-7J/cm2), pulse repetition rate (1Hz-35Hz), and spot size (0.004cm2-0.12cm2) was studied. Additionally, the effect of fluence and pulse repetition rate on dentin microstructure was studied using scanning electron microscopy (SEM). It is demonstrated that this "cold ablation" excimer laser can result in significant thermal modification in the dentin surfaces. Changes include the formation of melted dentin grains, which uniformly cover the surface and the exposed dentin tubules. Maximum temperatures of the ablated surfaces, however, remained relatively low at most laser parameters used. Also, the immediate neighborhood of the root canal was essentially undisturbed at most laser parameters. These observations suggest that with the appropriate choice of parameters XeCl lasers can be effective in producing surface structures that may prove useful in enhancing bond strength or other applications in dentistry, without exposing tooth pulp to significant temperature elevation. PMID:8515674

  5. 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

  6. 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.

  7. 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.

  8. Estudio de la variación de la permeabilidad de la dentina radicular usando isótopos 99mTc, después de la aplicación de láser de alta intensidad Study of the dentin root permeability variation using 99mTc isotopes, after the application of high intensity laser

    Directory of Open Access Journals (Sweden)

    R. Cabrales Salgado

    2012-02-01

    containing 1 ml of saline. After 1 hour, the account of the radioactive isotope (99mTc was performed. Results: After statistical analysis (ANOVA found that the best results in terms of decreased permeability were found in Group 3, followed by Group 2 and Group 1. Conclusion: We conclude that irradiation with Nd: YAG caused a significant decrease in the permeability of root canal dentin. Laser Er: YAG and control in relation to the dentin permeability of root canal walls showed no statistically significant differences at 5%.

  9. Surface modification of tooth root canal after application of an X-ray opaque waveguide

    Science.gov (United States)

    Dostálová, T.; Jelínková, H.; Šulc, J.; Němec, M.; Koranda, P.; Bartoňová, M.; Radina, P.; Miyagi, M.; Shi, Y.-W.; Matsuura, Y.

    The interest in endodontic use of dental laser systems has been increasing. With the development of thin and flexible delivery systems for various wavelengths, laser applications in endodontics may become even more desirable. The aim of this study is to check the X-ray opacity of a hollow waveguide and to observe the results after laser root canal treatment. The root canal systems of 10 molars were treated endodontically by laser. For the laser radiation source, an Er:YAG laser system generating a wavelength of 2940 nm and an Alexandrite laser system generating a wavelength of 375 nm were used. The hollow waveguide used was checked under X-ray . A root canal surface treated by laser radiation was analyzed by a scanning electron microscope (SEM). The special hollow glass waveguide used was visible in the root canal system under X-ray imaging. Surface modification of the root canal after laser treatment was not found. After conventional treatment the root canal was enlarged. The surface was covered with a smear layer. After application of both laser systems, the smear layer was removed. The resulting canal surface was found to be clean and smooth. Under SEM observation open dentinal tubules were visible. No cracks were present, nor were surface modifications observed.

  10. First Branchial Cleft Fistula Associated with External Auditory Canal Stenosis and Middle Ear Cholesteatoma

    Directory of Open Access Journals (Sweden)

    shahin abdollahi fakhim

    2014-10-01

    Full Text Available Introduction: First branchial cleft anomalies manifest with duplication of the external auditory canal.   Case Report: This report features a rare case of microtia and congenital middle ear and canal cholesteatoma with first branchial fistula. External auditory canal stenosis was complicated by middle ear and external canal cholesteatoma, but branchial fistula, opening in the zygomatic root and a sinus in the helical root, may explain this feature. A canal wall down mastoidectomy with canaloplasty and wide meatoplasty was performed. The branchial cleft was excised through parotidectomy and facial nerve dissection.   Conclusion:  It should be considered that canal stenosis in such cases can induce cholesteatoma formation in the auditory canal and middle ear.

  11. Etidronate from Medicine to Endodontics: effects of different irrigation regimes on root dentin roughness

    Directory of Open Access Journals (Sweden)

    Talita Tartari

    2013-09-01

    Full Text Available An increase in dentin roughness, associated with surface composition, contributes to bacterial adherence in recontaminations. Surface roughness is also important for micromechanical interlocking of dental materials to dentin, and understanding the characteristics of the surface is essential to obtain the adhesion of root canal sealers that have different physico-chemical characteristics. OBJECTIVES: To evaluate the effects of sodium hypochlorite (NaOCl, ethylenediaminetetraacetic (EDTA, etidronic (HEBP, and citric acid (CA associated with different irrigation regimens on root dentin roughness. MATERIAL AND METHODS: Forty-five root halves of anterior teeth were used. The root parts were sectioned in thirds, embedded in acrylic resin and polished to a standard surface roughness. Initially, the samples of each third were randomly assigned into 3 groups and treated as follows: G1 - saline solution (control; G2 - 5% NaOCl+18% HEBP mixed in equal parts; and G3 - 2.5% NaOCl. After initial measuments, the G3 samples were distributed into subgroups G4, G5 and G6, which were subjected to 17% EDTA, 10% CA and 9% HEBP, respectively. Following the new measuments, these groups received a final flush with 2.5% NaOCl, producing G7, G8 and G9. The dentin surface roughness (Ra was determined before and after treatments using a profilometer. The Wilcoxon test (α<0.05 was used to compare the values before and after treatments, and the Friedman test (α<0.05 to detect any differences among root thirds. RESULTS: (i NaOCl did not affect the surface roughness; (ii there was a significant increase in roughness after the use of chelating agents (P<0.01; and (iii only the G3 group showed a difference in surface roughness between apical third and other thirds of the teeth (P<0.0043. CONCLUSION: Only the irrigation regimens that used chelating agents altered the roughness of root dentin.

  12. Tissue dissolution and modifications in dentin composition by different sodium hypochlorite concentrations

    Science.gov (United States)

    TARTARI, Talita; BACHMANN, Luciano; MALIZA, Amanda Garcia Alves; ANDRADE, Flaviana Bombarda; DUARTE, Marco Antonio Hungaro; BRAMANTE, Clovis Monteiro

    2016-01-01

    ABSTRACT Sodium hypochlorite (NaOCl) remains the most used irrigation solution during root canal preparation because of characteristics such as wide-spectrum antimicrobial activity and organic tissue dissolution capacity. However, these solutions can alter dentin composition and there is no consensus on the optimal concentration of NaOCl to be used. Objectives To determine the organic matter dissolution and changes in dentin chemical composition promoted by different concentrations of NaOCl over time. Material and Methods: Fragments of bovine muscle tissue were weighed before and after 5, 10, and 15 min of immersion in the groups (n=10): G1- 0.9% saline solution; G2- 1% NaOCl; G3- 2.5% NaOCl; and G4- 5% NaOCl. Bovine dentin fragments were subjected to the same irrigants and absorption spectra were collected by Attenuated Total Reflectance of Fourier Transform Infrared Spectroscopy (ATR-FTIR) before and after 0,5, 1, 2, 3, 5, 8, and 10 min of immersion in the solutions. The ratios of the amide III/phosphate and carbonate/phosphate absorption bands were determined. The tissue dissolution and carbonate/phosphate ratios were submitted to the two-way analysis of variance (ANOVA) with Tukey’s multiple-comparison test (α0.05). Intergroup differences were not observed in this ratio (p>0.05). Conclusions The increase in the exposure time and in the concentration of NaOCl solution lead to an increase in the tissue dissolution and dentin collagen deproteination. Furthermore, some carbonate ions are removed from the dentin inorganic phase by the NaOCl. PMID:27383711

  13. The role of perilymph in the response of the semicircular canals to angular acceleration.

    Science.gov (United States)

    Anliker, M.; Van Buskirk, W.

    1971-01-01

    A new model for the response of the semicircular canals to angular motion is postulated. This model is based on evidence that the bony canal is not compartmentalized and assumes that the ampulla wall is highly flexible. It is shown that the perilymph induces a cupula displacement far greater than that produced by the endolymph alone. The predicted dynamic behavior of the canals on the basis of this model is found to be consistent with experimental observations.

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

    International Nuclear Information System (INIS)

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

  15. Nanoleakage of dentin adhesive systems bonded to Carisolv-treated dentin.

    Science.gov (United States)

    Kubo, Shisei; Li, Heping; Burrow, Michael F; Tyas, Martin J

    2002-01-01

    The hybrid layer created in caries-affected dentin has not been fully elucidated and may influence bond durability. This study investigated the nanoleakage patterns of caries-affected dentin after excavation with Carisolv or conventional instruments treated with one of three adhesive systems. Flat occlusal dentin surfaces, including carious lesions, were prepared from extracted human molars and finished with wet 600-grit silicon carbide paper. Carious dentin was removed with Carisolv or round steel burs in conjunction with Caries Detector. PermaQuik, Single Bond or One-Up Bond F was bonded to the excavated dentin surfaces and adjacent flat occlusal surfaces and it was covered with Silux Plus resin-based composite. After 24-hour storage in 37 degrees C water, the bonded interfaces were polished to remove flash, and the surrounding tooth surfaces were coated with nail varnish. Specimens were immersed in 50% (w/v) silver nitrate solution for 24 hours, exposed to photo developing solution for eight hours, then sectioned longitudinally through the bonded, excavated dentin or "normal" dentin surfaces. The sectioned surfaces were polished, carbon coated and observed in a Field Emission-SEM using back scattered electrons. Silver deposition occurred along the base of the hybrid layer for all specimens. However, Single Bond showed a greater density of silver deposition in the caries-affected dentin compared with normal dentin. PermaQuik had a thicker hybrid layer in caries-affected dentin than normal dentin. One-Up Bond F exhibited a thin hybrid layer in normal dentin, but the hybrid layer was often difficult to detect in caries-affected dentin. PMID:12120777

  16. In vitro study of the effect of Er: YAG laser irradiation on the apical sealing of different root canal sealers Estudo "in vitro" do efeito da irradiação do laser Er: YAG no selamento apical de diferentes tipos de cimentos obturadores

    Directory of Open Access Journals (Sweden)

    Fernanda Vieira Medina

    2006-08-01

    Full Text Available OBJECTIVES: The aim of this study was to determine the effect of Er:YAG laser irradiation used to clean dentinal walls on the apical sealing of root canals filled with different types of sealers. Background Data: Laser application to the dentinal walls removed debris, rendering the root canals free of smear layers and leaving the dentinal canaliculi open. METHODS: Sixty-four maxillary canines obtained from laboratory files were instrumented with K-files (Dentsply, Maillefer, Ballaigues, Switzerland using the crown-down technique, and irrigated with a 0.5% sodium hypochlorite solution. The specimens were divided into two groups of 32 teeth each. In group I, the teeth were instrumented and irrigated with sodium hypochlorite solution, and divided into four subgroups to be sealed with the different materials (Endofill, N-Rickert, Sealapex and Sealer 26. In group II, the root canals were subjected to Er:YAG laser irradiation (200 mJ, 7 Hz and 60 J total energy, followed by root canal sealing as in group I. RESULTS: The data showed lower levels of apical microleakage in the teeth filled with N-Rickert, Sealapex and Sealer 26 cements than in those sealed with Endofill (p 0.05. CONCLUSIONS: The Er:YAG laser irradiation applied to the root canal walls was not able to prevent apical microleakage.OBJETIVOS: Avaliou-se a infiltração marginal apical em caninos superiores, obturados com quatro tipos diferentes de cimento, os quais foram imersos em tinta nanquim e mantidos a uma temperatura de 37º C por 96 horas, descalcificados em solução de ácido clorídrico a 5%, desidratados em série crescente de álcoois e diafanizados em salicilato de metila. MÉTODOS: Para isto, 64 dentes de estoque foram instrumentados pela técnica "crown-down", irrigados com solução de hipoclorito de sódio a 0,5% e divididos em dois grupos experimentais. Os dentes do Grupo I foram subdivididos em quatro sub-grupos de oito elementos e obturados cada um deles com os cimentos

  17. Canals, River Irrigation Company Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2002. It is described as 'River Irrigation Company Canal'. Data by this publisher are...

  18. Canals, Lake Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2002. It is described as 'Lake Canal'. Data by this publisher are often provided in...

  19. Canals, Yellowstone Feeder Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2002. It is described as 'Yellowstone Feeder Canal'. Data by this publisher are often...

  20. Canals, Bypass Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2002. It is described as 'Bypass Canal'. Data by this publisher are often provided in...

  1. Ear canal cholesteatoma.

    Science.gov (United States)

    Holt, J J

    1992-06-01

    Although cholesteatomas are more commonly found in the middle ear and the mastoid, the disease can occur in the external ear canal. All cases of ear canal cholesteatoma treated by the author were reviewed. There were nine ears in seven patients, who had an average age of 62 years. The lesions ranged in size from a few millimeters to extensive mastoid destruction. Smaller lesions can be managed by frequent cleaning as an office procedure. Larger lesions require surgery, either canaloplasty or mastoidectomy. The otolaryngologist should suspect this disease in the elderly. Microscopic examination of the ear with meticulous cleaning of all wax, especially in elderly patients, is most useful in detecting early disease. Frequent applications of mineral oil to the canal should be used in the management of the disease and to prevent recurrence. PMID:1376388

  2. Evaluation of Osteoconductive and Osteogenic Potential of a Dentin-Based Bone Substitute Using a Calvarial Defect Model

    Directory of Open Access Journals (Sweden)

    Ibrahim Hussain

    2012-01-01

    Full Text Available The aim of this study was to assess the osteoconductive and osteogenic properties of processed bovine dentin using a robust rabbit calvarial defect model. In total, 16 New Zealand White rabbits were operated to create three circular defects in the calvaria. One defect was left unfilled, one filled with collected autogenous bone, and the third defect was filled with the dentin-based bone substitute. Following surgery and after a healing period of either 1 or 6 weeks, a CT scan was obtained. Following sacrificing, the tissues were processed for histological examination. The CT data showed the density in the area grafted with the dentin-based material was higher than the surrounding bone and the areas grafted with autologous bone after 1 week and 6 weeks of healing. The area left unfilled remained an empty defect after 1 week and 6 weeks. Histological examination of the defects filled with the dentin product after 6 weeks showed soft tissue encapsulation around the dentin particles. It can be concluded that the rabbit calvarial model used in this study is a robust model for the assessment of bone materials. Bovine dentin is a biostable material; however, it may not be suitable for repairing large 4-wall defects.

  3. Ecological Hypothesis of Dentin and Root Caries.

    Science.gov (United States)

    Takahashi, Nobuhiro; Nyvad, Bente

    2016-01-01

    Recent advances regarding the caries process indicate that ecological phenomena induced by bacterial acid production tilt the de- and remineralization balance of the dental hard tissues towards demineralization through bacterial acid-induced adaptation and selection within the microbiota - from the dynamic stability stage to the aciduric stage via the acidogenic stage [Takahashi and Nyvad, 2008]. Dentin and root caries can also be partly explained by this hypothesis; however, the fact that these tissues contain a considerable amount of organic material suggests that protein degradation is involved in caries formation. In this review, we compiled relevant histological, biochemical, and microbiological information about dentin/root caries and refined the hypothesis by adding degradation of the organic matrix (the proteolytic stage) to the abovementioned stages. Bacterial acidification not only induces demineralization and exposure of the organic matrix in dentin/root surfaces but also activation of dentin-embedded and salivary matrix metalloproteinases and cathepsins. These phenomena initiate degradation of the demineralized organic matrix in dentin/root surfaces. While a bacterial involvement has never been confirmed in the initial degradation of organic material, the detection of proteolytic/amino acid-degrading bacteria and bacterial metabolites in dentin and root caries suggests a bacterial digestion and metabolism of partly degraded matrix. Moreover, bacterial metabolites might induce pulpitis as an inflammatory/immunomodulatory factor. Root and dentin surfaces are always at risk of becoming demineralized in the oral cavity, and exposed organic materials can be degraded by host-derived proteases contained in saliva and dentin itself. New approaches to the prevention and treatment of root/dentin caries are required. PMID:27458979

  4. Comparison of different retreatment techniques and root canal sealers: a scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Neslihan Simsek

    2014-05-01

    Full Text Available The aim of this study was to evaluate the effectiveness of two retreatment techniques, in terms of the operating time and scanning electron microscopy (SEM results, in removing three different root canal sealers from root canals that were previously filled with gutta-percha. Sixty extracted single-rooted human premolars were divided into three groups and filled with iRoot SP, MM Seal, and AH Plus sealers, along with gutta-percha, through a lateral compaction technique. Root canal fillings of the samples were removed by ESI ultrasonic tips or R-Endo files. The time to reach the working length was recorded. Longitudinally sectioned samples were examined under SEM magnification. Each picture was evaluated in terms of the residual debris. Data were statistically analyzed with the Kruskall-Wallis test. No statistically significant differences were found in terms of operating time (p>0.05. Significant differences in the number of debris-free dentinal tubules were found among the root canal thirds, but this finding was not influenced by the experimental group (p < 0.05. Resin sealer tags were observed inside the dentinal tubules in the MM Seal group. Under the conditions of this study, it may be established that there was no difference among the sealers and retreatment techniques.

  5. Love canal questions

    Science.gov (United States)

    Bell, Peter M.

    The Environmental Protection Agency (EPA) conducted a 3-month monitoring study of the Love Canal area near Niagara Falls, N.Y., after the federal government pronounced that a potential health risk existed due to chemical waste dumps. In 1982 the Department of Health and Human Services (HHS) decided that the area was habitable, subject to implementation of effective safeguards against leakage from the canal and to cleaning up of the contaminants. Now, the Congressional Office of Technology Assessment (OTA) has announced that, with the information available, it is not possible to demonstrate with certainty that unsafe levels do not exist within the so-called “emergency declaration area” (EDA).

  6. Dentin hypersensitivity: differential diagnosis, tests, and etiology.

    Science.gov (United States)

    Trushkowsky, Richard D; Garcia-Godoy, Franklin

    2014-02-01

    Dentin hypersensitivity (DHS) is a painful condition that affects up to 57 percent of the adult population. It occurs as a result of exposure of dentin to the oral environment. Ensuring the correct diagnosis of this condition is based on history and examination. An oral screening for DHS should encompass such elements as patient history, clinical examination that includes radiographs, a variety of tests, identification of risk factors, and a differential diagnosis. An understanding of dentinal fluid and odontoblasts is also beneficial for diagnosis. PMID:24571559

  7. 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.

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

    OpenAIRE

    Mirzakoucheki, Parvin; Walter, Ricardo; Khalighinejad, Navid; Jahromi, Maryam Zare; Mirsattari, Sanaz; Akbarzadeh, Navid

    2015-01-01

    Objectives The aim of this study was to evaluate the effects of tri-antibiotic paste (TAP) on microtensile bond strengths (MTBS) of dental adhesives to dentin. Materials and Methods Sixty extracted molars had their occlusal surfaces flattened to expose dentin. They were divided into two groups, i.e., control group with no dentin treatment and experimental group with dentin treatment with TAP. After 10 days, specimens were bonded using self-etch (Filtek P90 adhesive) or etch-and-rinse (Adper S...

  9. Differences in cytotoxicity between 5% tetracycline hydrochloride and 15% EDTA as root canal irrigant

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    Devi Eka Juniarti

    2008-06-01

    Full Text Available 5% tetracycline hydrochloride and 15% EDTA as a root canal irrigant have been proven to be able to remove smear layer, open dentinal tubules and have antimicrobial activity. An effective root canal irrigation solution must be able to dissolve organic and anorganic debris, lubricate endodontic instruments, disinfect microorganism and non toxic. The purpose of this laboratory experimental study was to determine cytotoxicity differences between 5% tetracycline hydrochloride and 15% EDTA. 21 samples were used and classified into 3 groups: control, 5% tetracycline hydrochloride and 15% EDTA groups. Cytotoxicity test was done using BHK21 cells. The data was analyzed using Bird and Forrester formula. It concluded that 5% tetracycline hydrochloride more toxic than 15% EDTA as a root canal irrigant.

  10. Identification of dentin phosphophoryn localization by histochemical stainings.

    Science.gov (United States)

    Takagi, Y; Fujisawa, R; Sasaki, S

    1986-01-01

    Phosphophoryn, the most abundant of the dentin non-collagenous proteins, has been considered to be related in function to the mineralization process. In the present study, identification of dentin phosphophoryn localization was attempted using newly developed, precautionary histological methods by which phosphophoryn was retained in the sections during the specimen preparation and stained selectively in situ. Phosphophoryn was found to be present widely in all of the calcified dentin except the mantle dentin, the external, first-formed portion of dentin, but was not found in the predentin, the inner, uncalcified layer of dentin. These results indicate that phosphophoryn is apparently related to the mineral phase of calcified dentin and that the mineralization process of mantle dentin, which is formed before the odontoblasts are fully differentiated, may be different from that of circumpulpal dentin. PMID:2421974

  11. 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.

  12. Root dentin strain and temperature rise during endodontic treatment and post rehabilitation.

    Science.gov (United States)

    Amade, Euridsse Sulemane; Novais, Veridiana Resende; Roscoe, Marina Guimarães; Azevedo, Fabiane Maria Ferreira; Bicalho, Aline Aredes; Soares, Carlos José

    2013-01-01

    This study investigated the effects of endodontic treatment procedures and different post systems rehabilitation steps on the strain and temperature rise on apical and cervical root dentin regions. Twenty-one extracted human canine teeth had two strain gages attached to the distal root surface and two thermocouples attached to the mesial root surface (cervical and apical). The strain and temperature rise were recorded during the following procedures: root canal preparation, final rinse and drying, root canal filling and canal relief. Then the teeth were divided into three groups (n=7), according to the type of post system: CPC, cast post and core; FGP, fiberglass post; and PSP, prefabricated steel post. Data continued to be recorded during the post space preparation, post modeling (only for CPC), post trying and post cementation. Data were subjected to a two-way ANOVA followed by Tukey's test (α=0.05). The post-space preparation caused the highest temperature rise (4.0-14.9 °C) and the highest strain in the apical region during irrespective of post type. The resin cement light-activation resulted in significant temperature increases in the cervical region for all of the groups. The canal relief and the post-space preparation produced highest temperature rises. The CPC post modeling resulted in higher root strain level similarly the level of post preparation. The PSP resulted in highest strain during post trying and post cementation.

  13. Root Canal Morphology of Permanent Maxillary and Mandibular Canines in Indian Population Using Cone Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    Nikhita Somalinga Amardeep

    2014-01-01

    Full Text Available Aim. To investigate the root canal anatomy of single-rooted permanent maxillary and mandibular canines in an Indian population using cone beam computed tomography (CBCT. Methodology. A total of 250 permanent maxillary canines and 250 permanent mandibular canines were selected and scanned using CBCT. The root anatomy of each tooth was evaluated for the following parameters: the pattern of the root canals, anatomic length of the crown and the root, the presence of accessory canals, the shape of the access cavity, the position of the apical foramina, root diameter, and dentin thickness of the root. Results. Majority of the teeth had a Type I canal configuration in both maxillary canines (81.6% and mandibular canines (79.6%. In maxillary canine the other canal patterns found were Type III (11.6%, Type II (2.8%, Type V (2%, Type XIX (1.2%, and Type IV (0.8%. In mandibular canines the various other canal patterns found were Type III (13.6%, Type II (3.2%, Type V (2%, and Type XIX (1.6%. Apical foramina were laterally positioned in the majority of the teeth, 70.4% and 65.6% in maxillary and mandibular canines, respectively. 12% of the maxillary canines and 12.8% of the mandibular canines had accessory canals. Conclusion. The root canal anatomy of permanent maxillary and mandibular canines varied widely in an Indian population.

  14. Bacterial coronal leakage after obturation with three root canal sealers.

    Science.gov (United States)

    Timpawat, S; Amornchat, C; Trisuwan, W R

    2001-01-01

    The purpose of this study was to compare the bacterial leakage of root canals obturated with three root canal sealers, using Endodontalis faecalis as a microbial tracer to determine the length of time for bacteria to penetrate through the obturated root canal to the root apex. Seventy-five, single-rooted teeth with straight root canals had the crown cut off at the cementoenamel junction. Root canals were instrumented by a step-back technique. The prepared teeth were randomly divided into 3 groups of 19 teeth each and another 2 groups as positive and negative controls (9 teeth each). The experimental groups were dependent on the sealer used: AH-Plus, Apexit, and Ketac-Endo. The root canals were obturated using a lateral condensation technique. After 24 h the teeth were attached to microcentrifuge tubes with 2 mm of the root apex submerged in Brain Heart Infusion broth in glass test tubes. The coronal portions of the root canal filling materials were placed in contact with E. faecalis. The teeth were observed for bacterial leakage daily for 30 and 60 days. With the chi2 test for comparing pairs of groups at the 0.05 level (p 0.06), but Apexit had significantly higher leakage (p 0.05), but Apexit leaked more than AH-Plus. The conclusion drawn from this experiment was that epoxy resin root canal sealer was found to be more adaptable to the root canal wall and filling material than a calcium hydroxide sealer when bacterial coronal leakage was studied.

  15. Chlorhexidine Preserves Dentin Bond in vitro

    OpenAIRE

    Carrilho, M. R. O.; Carvalho, R. M.; de Goes, M. F.; di Hipólito, V.; Geraldeli, S.; Tay, F.R.; Pashley, D.H.; Tjäderhane, L.

    2007-01-01

    Loss of hybrid layer integrity compromises resin-dentin bond stability. Matrix metalloproteinases (MMPs) may be partially responsible for hybrid layer degradation. Since chlorhexidine inhibits MMPs, we hypothesized that chlorhexidine would decelerate the loss of resin-dentin bonds. Class I preparations in extracted third molars were sectioned into two halves. One half was customarily restored (etch-and-rinse adhesive/resin composite), and the other was treated with 2% chlorhexidine after bein...

  16. 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.

  17. Aspects of solvents in dentine bonding

    OpenAIRE

    Ekambaram, Manikandan

    2015-01-01

    Degradation starts at the resin-dentine bonded interfaces within a few months’ of bonding. There are two major causes of degradation of the bonded interfaces over time. The simplified dental adhesives that are routinely used in the contemporary clinical dental practice are extremely hydrophilic and are prone to water sorption, leading to hydrolytic degradation. Dentine matrix-bound metalloproteinases (MMPs) and cysteine cathepsins (CCs) are proteolytic enzymes that have been shown to degrade ...

  18. Dentin hypersensitivity: Recent trends in management

    OpenAIRE

    Miglani Sanjay; Aggarwal Vivek; Ahuja Bhoomika

    2010-01-01

    Dentinal hypersensitivity (DH) is a common clinical condition usually associated with exposed dentinal surfaces. It can affect patients of any age group and most commonly affects the canines and premolars of both the arches. This article concisely reviews the patho-physiology, mechanism and clinical management of the DH. Treatment of DH should start with an accurate diagnosis. Differential diagnosis should be made and all other probable causes should be excluded. An often neglected phase of c...

  19. Comparative evaluation of microleakage of newer generation dentin bonding agents: An in vitro study

    OpenAIRE

    Rani Somani; Shipra Jaidka; Sameksha Arora

    2016-01-01

    Context: Adhesive dentistry has been progressing with rapid pace over the past decade. Composite resin is the most esthetic restorative material currently available for restoring teeth. In spite of it being in use since a decade, still failure cases are seen which are mainly due to polymerization shrinkage and subsequent inadequate adhesion to cavity walls, leading to microleakage. Various generations of dentin bonding agents have been introduced to overcome the shortcoming of composite resin...

  20. Curved canals: Ancestral files revisited

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    Jain Nidhi

    2008-01-01

    Full Text Available The aim of this article is to provide an insight into different techniques of cleaning and shaping of curved root canals with hand instruments. Although a plethora of root canal instruments like ProFile, ProTaper, LightSpeed ® etc dominate the current scenario, the inexpensive conventional root canal hand files such as K-files and flexible files can be used to get optimum results when handled meticulously. Special emphasis has been put on the modifications in biomechanical canal preparation in a variety of curved canal cases. This article compiles a series of clinical cases of root canals with curvatures in the middle and apical third and with S-shaped curvatures that were successfully completed by employing only conventional root canal hand instruments.

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

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    Kun Ismiyatin

    2010-06-01

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

  2. 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.

  3. 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.

  4. Managing curved canals

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    Iram Ansari

    2012-01-01

    Full Text Available Dilaceration is the result of a developmental anomaly in which there has been an abrupt change in the axial inclination between the crown and the root of a tooth. Dilaceration can be seen in both the permanent and deciduous dentitions, and is more commonly found in posterior teeth and in maxilla. Periapical radiographs are the most appropriate way to diagnose the presence of root dilacerations. The controlled regularly tapered preparation of the curved canals is the ultimate challenge in endodontics. Careful and meticulous technique will yield a safe and sufficient enlargement of the curved canals. This article gives a review of the literature and three interesting case reports of root dilacerations.

  5. Influence of the glide path on various parameters of root canal prepared with WaveOne reciprocating file using cone beam computed tomography

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    Anil Dhingra

    2015-01-01

    Full Text Available Background: Nickel-titanium (NiTi rotary instrumentation carries a risk of fracture, mainly as a result of flexural (fatigue fracture and torsional (shear failure stresses. This risk might be reduced by creating a glide path before NiTi rotary instrumentation. The aim of this study was to compare various root canal parameters with the new WaveOne single-file reciprocating system in mesial canals of mandibular molars with and without glide path using cone beam computed tomography (CBCT. Materials and Methods: One hundred mandibular molar teeth with canal curvature between 20° and 30° were divided into two groups of 50 teeth each. In Group 1, no glide path was created, whereas in Group 2, a glide path was created with PathFiles at working length (WL. In both groups, canals were shaped with WaveOne primary reciprocating files to the WL. Canals were scanned in a CBCT unit before and after instrumentation. Postinstrumentation changes in canal curvature, cross-sectional area, centric ability, residual dentin thickness, and the extent of canal transportation were calculated using image analysis software and subjected to statistical analysis. Data were analyzed using Student′s t-test and Mann-Whitney U-test (P < 0.05. Results: The mean difference of root canal curvature, cross-sectional area, centric ability, and residual dentin thickness increased, whereas it reduced significantly for canal transportation in Group 2. Conclusion: WaveOne NiTi files appeared to maintain the original canal anatomy and the presence of a glide path further improves their performance and was found to be beneficial for all the parameters tested in this study.

  6. Metachronous tubulovillous and tubular adenomas of the anal canal.

    Science.gov (United States)

    Nozawa, Hiroaki; Ishihara, Soichiro; Morikawa, Teppei; Tanaka, Junichiro; Yasuda, Koji; Ohtani, Kensuke; Nishikawa, Takeshi; Tanaka, Toshiaki; Kiyomatsu, Tomomichi; Kawai, Kazushige; Hata, Keisuke; Kazama, Shinsuke; Yamaguchi, Hironori; Sunami, Eiji; Kitayama, Joji; Fukayama, Masashi; Watanabe, Toshiaki

    2015-01-01

    Anal canal adenoma is an extremely rare disease that has the potential to transform into a malignant tumor. We herein presented a rare case of metachronous multiple adenomas of the anal canal. A 48-year-old woman underwent total colonoscopy following a positive fecal blood test. A 9-mm villous polyp arising from the posterior wall of the anal canal was removed by snare polypectomy. Histologically, the tumor was tubulovillous adenoma with high-grade dysplasia and the cut end was negative for tumor cells. Six years later, an elevated lesion, macroscopically five millimeters in size, was detected in the left wall of the anal canal in a follow-up colonoscopy. Local excision of the tumor was performed, and the lesion was pathologically confirmed to be tubular adenoma with high-grade dysplasia limited to the mucosa. The patient is currently alive without any evidence of recurrence for six months after surgery. Although she had a past history of cervical cancer, the multiple tumors arising in the anal canal were unlikely to be related to human papilloma virus infection. Our case report underscores the importance of careful observations throughout colonoscopy to detect precancerous lesions, particularly in anatomically narrow segments. PMID:26249723

  7. The Effect of Diode Laser Treatment for Root Canal Disinfection on Fracture Resistance and Micro-hardness of the Tooth

    International Nuclear Information System (INIS)

    This study evaluated the effect of diode laser treatment for root canal disinfection on fracture resistance and micro-hardness of the tooth. Sixty freshly extracted mandibular and maxillary premolars were accessed under coolant then root canals were flared up to apical preparation size 40 MFA coupled with 5.25% NaOCl as an irrigant. Teeth were divided into two groups, control group (group I) and lased group (group II) that was lased by diode laser with average power 2 w through fibrooptic into the canal 2 mm shorter than the apex. Each tooth was embedded in acrylic block, and then subjected to the fracture resistance test. Each root was then sectioned transversely and polished to record dentin Vickers hardness. Data was analysed with student t-test then with linear regression test. The Lased samples presented a significantly higher resistance to fracture than unlased samples. There was no statistically significant differences found between Vickers hardness (HV) of lased and unlased samples and there was no relation between fracture resistance and microhardness. Diode laser (980 nm) treatment had no adverse effect on dentin microhardness, also it increased the fracture resistance of dentin. Diode laser (980 nm) treatment could attain better function ability and maintenance of tooth after endodontic treatment.

  8. Characterization of dentine to assess bond strength of dental composites

    OpenAIRE

    Saad Liaqat; Anas Aljabo; Muhammad Adnan Khan; Hesham Ben Nuba; Laurent Bozec; Paul Ashley; Anne Young

    2015-01-01

    This study was performed to develop alternating dentine adhesion models that could help in the evaluation of a self-bonding dental composite. For this purpose dentine from human and ivory was characterized chemically and microscopically before and after acid etching using Raman and SEM. Mechanical properties of dentine were determined using 3 point bend test. Composite bonding to dentine, with and without use of acid pre-treatment and/or the adhesive, were assessed using a shear bond test. F...

  9. Effect of chitosan-ethylenediamine tetraacetic acid on Enterococcus faecalis dentinal biofilm and smear layer removal

    Science.gov (United States)

    Geethapriya, Nagarajan; Subbiya, Arunajatesan; Padmavathy, Kesavaram; Mahalakshmi, Krishnan; Vivekanandan, Paramasivam; Sukumaran, Virudhachalam Ganapathy

    2016-01-01

    Objective: The objective of the study was to evaluate the effectiveness of chitosan and chitosan-ethylenediamine tetraacetic acid (EDTA) (3:1,1:1,1:3) in comparison with 5.2% sodium hypochlorite (NaOCl) in disinfecting Enterococcus faecalis biofilm on root canal dentin and in the removal of smear layer with minimal erosion. Materials and Methods: Seventy single-rooted extracted human mandibular premolars (n = 70) were selected for the study. Forty tooth samples were biomechanically prepared, vertically sectioned, and sterilized by autoclaving. The tooth sections were artificially infected with E. faecalis (ATCC 29212 [n = 35] and clinical isolate [SBEF2, n = 35]) to form mature dentinal biofilm in vitro. The tooth samples were treated with the test solutions: chitosan and chitosan-EDTA (3:1, 1:1, 1:3), and the killing time was determined. The smear layer removal ability of the test solutions (Group A: chitosan-EDTA [1:1], Group B: EDTA, Group C: control) (n = 10 tooth/group) was assessed. Results: Chitosan and chitosan-EDTA (3:1, 1:1, 1:3) exhibited antibacterial activity against both the strains of E. faecalis. Chitosan and chitosan-EDTA caused 3 log reduction in the viable count of the sessile cells of E. faecalis at 15 min while 5.2% NaOCl exhibited 99.98% inhibition at 15 min. Chitosan-EDTA (1:1) was found to be effective in removing the smear layer and showed lesser erosion than EDTA at the coronal and middle portions. Conclusion: Chitosan-EDTA (1:1) is a potential root canal irrigant that performs a dual role – root canal disinfection and smear layer removal. PMID:27656070

  10. Bond strength of different endodontic sealers to dentin: push-out test

    Directory of Open Access Journals (Sweden)

    João Vicente Baroni Barbizam

    2011-12-01

    Full Text Available OBJECTIVE: The aim of this in vitro study was to evaluate the bond strength of different root canal sealers to dentin. MATERIAL AND METHODS: Forty extracted single-rooted human teeth were examined and the coronal and middle thirds of the canals were prepared with a 1.50 mm post drill (FibreKor Post System, Pentron. The teeth were allocated in two experimental groups, irrigated with 2.5% NaOCl+17% EDTA or saline solution (control group and instrumented using Race rotary files (FKG to a size #40 at the working length. Then, the groups were divided into four subgroups and filled with Epiphany sealer (Group 1, EndoREZ (Group 2, AH26 (Group 3 and Grossman's Sealer (Group 4. After 2 weeks of storage in 100% humidity at 37ºC, all teeth were sectioned transversally into 2-mm-thick discs. Push-out tests were performed at a cross-head speed of 1 mm/min using a universal testing machine. The maximum load at failure was recorded and expressed in MPa. RESULTS: Means (±SD in root canals irrigated with 2.5% NaOCl and 17% EDTA were: G1 (21.6±6.0, G2 (15.2±3.7, G3 (14.6±4.5 and G4 (11.7±4.1.Two-way ANOVA and Tukey's test showed the highest bond strength for the Epiphany's group (p< 0.01 when compared to the other tested sealers. Saline solution decreased the values of bond-strength (p<0.05 for all sealers. CONCLUSION: Epiphany sealer presented higher bond strength values to dentin in both irrigating protocols, and the use of 2.5% NaOCl and 17% EDTA increased the bond strength values for all sealers.

  11. An ex vivo comparison of detection ability of three methods in discovering of MB2 canal in maxillary molars

    Directory of Open Access Journals (Sweden)

    Ghorbanzadeh A.

    2009-11-01

    Full Text Available "nBackground and Aim: A considerable percentage of failure in Endodontic treatments in maxillary molars is attributed to undiscovered second mesiobuccal canal (MB2.There are different methods for discovering and accessing to this canal. The purpose of this ex vivo study was to compare the detection ability of three methods (direct look, fiberoptic loup and surgical microscope to find MB2 after troughing with ultrasonic. "nMaterials and Methods: In this experimental study, we selected 90 extracted maxillary molars (45 first and 45 second molars in which after access cavity preparation MB2 canal was not discovered by direct vision and endodontic explorer. They were divided into 3 groups (n=30. The dentinal shelf between mesiobuccal and palatal canals was eliminated by an endodontic ultrasonic tip (troughing. After that, first group was searched by direct vision, second group by a loup and fiberoptic light and third group by dental operating microscope. Data were analyzed, specificity and sensitivity were calculated. "nResults: The results showed that 21%, 61%, and 92% of MB2 canals after troughing was found by direct vision, fiberoptic loup, and surgical microscope, respectively. "nConclusion: Based on the results of this study, surgical microscope and loup with fiberoptic are preferred methods for discovering MB2 canal. Troughing with ultrasonic can help find MB2 canal in all methods.

  12. The use of plastic models for teaching root canal cleansing and shaping

    Directory of Open Access Journals (Sweden)

    Eftekhar B

    2004-02-01

    Full Text Available The use of root canal models in endodontics education is of high importance. So, in this article"na new method is presented that the students can produce these models with simple and low cost"ninstruments."nThese plastic models are made of polyester which is low cost, available and has the approximate cutting"nproperties of dentin. The best molds were disposable syringes due to their low cost, availability and"nproducing smooth surfaces on polyester models. A spreader with desired curve and tapering is used for"nproducing canals. Rockwell A hardness coefficient of polyester is "33", which is near dentin "31" and"nforeign made models "35.5". Since these polyester models can tolerate up to 280°C and have acceptable"nresistance to chloroform, all root canal therapy techniques such as vertical condensation and retreatments"nare practicable. Their transparency encourage the students to work on them. As a result, the use of these"nmodels is recommended for endodontics training.

  13. Risk-Based Disposal Plan for PCB Paint in the TRA Fluorinel Dissolution Process Mockup and Gamma Facilities Canal

    Energy Technology Data Exchange (ETDEWEB)

    R. A. Montgomery

    2008-05-01

    This Toxic Substances Control Act Risk-Based Polychlorinated Biphenyl Disposal plan was developed for the Test Reactor Area Fluorinel Dissolution Process Mockup and Gamma Facilities Waste System, located in Building TRA-641 at the Reactor Technology Complex, Idaho National Laboratory Site, to address painted surfaces in the empty canal under 40 CFR 761.62(c) for paint, and under 40 CFR 761.61(c) for PCBs that may have penetrated into the concrete. The canal walls and floor will be painted with two coats of contrasting non-PCB paint and labeled as PCB. The canal is covered with open decking; the access grate is locked shut and signed to indicate PCB contamination in the canal. Access to the canal will require facility manager permission. Protective equipment for personnel and equipment entering the canal will be required. Waste from the canal, generated during ultimate Decontamination and Decommissioning, shall be managed and disposed as PCB Bulk Product Waste.

  14. 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

  15. Curative effect of cholesteatoma by canal wall-down mastoidectomy and type Ⅲa tympanoplasty%开放式乳突根治术并Ⅲa型鼓室成形术治疗胆脂瘤中耳炎的临床研究

    Institute of Scientific and Technical Information of China (English)

    翟锦明; 马钊恩; 陈观贵; 张建国

    2013-01-01

    Objective:To explore the curative effect and auditory outcomes in canal wall -down mastoidectomy and type Ⅲa tympanoplasty. Methods; Retrospective review of 62 patients with cholesteatoma , who underwent canal wall-down mastoidectomy and type Ⅲa tympanoplasty with titanium partial ossicular replacement prosthesis in a single stage. The postoperative complication , operation and aural rehabilitation were analyzed during 2-4 years follow-up. Results: In all 62 cases, 3 patients remained tympanic perforation , 6 patients with postoperative retraction pocket, 1 reurrence of cholesteatoma and 3 (3/62, 4.8%) extrusion of ossicular replacement prosthesis. The rate of total curative effectiveness was 58. 1% , dry ear was 91. 9% , postoperative infection rate was 8. 1%. Auditory outcomes showed that preoperative average air threshold (500, 1k, 2k, 4 k Hz) was (51. 0 ±13. 5) dB, postoperative (32. 6 ±8. 8 ) dB, and average air threshold reduction was statistically significant (t =16. 549, P <0. 01). Preoperative average air-bone gap was (35.2 ±10.0) dB, postoperative was (24.4 ±7.7) dB, with statistical significance (t = 11.276, P <0. 01). Conclusion: Canal wall-down mastoidectomy and type Ⅲa tympanoplasty with titanium partial ossicular replacement prosthesis in single stage is safe and effective surgery for chol -esteatoma, with less complication and relatively satisfactory hearing improvement . Application of tragal cartilage -perichondria autograft is of unique advantages .%目的:探讨开放式乳突根治术并Ⅲa型鼓室成形术治疗胆脂瘤中耳炎的临床效果.方法:62例胆脂瘤中耳炎患者均行开放式乳突根治术并Ⅲa型鼓室成形术(钛质部分听骨植入),随访2~4年,观察手术、术后并发症及听力恢复情况.结果:62例中3例鼓膜遗留穿孔,6例鼓膜内陷,1例胆脂瘤复发,3例(3/62,4.8%)听骨赝复物脱出,手术总有效率为58.1%,术后干耳率达91.9%,术后感染率为8.1%.

  16. 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

  17. 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.

  18. 12-Month color stability of enamel, dentine, and enamel-dentine samples after bleaching

    OpenAIRE

    Wiegand, Annette; Drebenstedt, S; Roos, Malgorzata; Magalhães, A C; Attin, Thomas

    2008-01-01

    The study aimed to quantify the color regression of enamel (E), dentine (D), and combined enamel-dentine (ED) of differently bleached ED specimens over a period of 12 months in vitro. Two ED samples were obtained from the labial surfaces of bovine teeth and prepared to a standardized thickness with the enamel and dentine layer each 1 mm. The ED samples were distributed on four groups (each n = 80), in which the different bleaching products were applied on enamel (1, Whitestrips; 2, Illuminé 1...

  19. Controversy at Love Canal.

    Science.gov (United States)

    Paigen, B

    1982-06-01

    A cancer researcher reviews the events surrounding the toxic waste contamination at Love Canal with emphasis on the political nature of the controversy about its health impact. Antagonism between the community and the New York State Department of Health was fueled by several factors: the state's awareness that it gained from delay in investigation, disagreement on health problems to be studied, control over the information gathering process, silencing of opposition opinion, and the violation of norms of scientific behavior. The author calls for the establishment of standards of ethical behavior for scientists in such situations, standards for conflict resolution, and means of appeal for those injured.

  20. The efficacy of an experimental single solution versus alternate use of multiple irrigants on root dentin microhardness

    OpenAIRE

    Akcay, Ilgin; Erdilek, Necdet; Sen, Bilge Hakan Sen

    2013-01-01

    Objectives: This study was carried-out to evaluate and compare the efficacy of various irrigants when used singly or in combination on the microhardness of root canal dentin. Study Design: A total of 50 root-halves were randomly divided into 5 groups immediately after the initial baseline microhardness measurements and treated with: Group-1; 7.5%Ethylenediaminetetraaceticacid (EDTA) + 2.5%sodium hypochlorite (NaOCl), Group-2; 7.5%ethyleneglycol-bis[b-aminoethylether]-N,N,N0,N0-tetraaceticacid...

  1. Transmission electron microscopic characterization of hypersensitive human radicular dentin

    International Nuclear Information System (INIS)

    Transmission electron microscopy (TEM) and x-ray microanalysis (XMA) were used for the study of the ultrastructure of the lumens of dentinal tubules in superficial layers of dentin specimens obtained by use of a new biopsy technique from both hypersensitive and naturally desensitized areas of exposed root surfaces, in vivo. The TEM images showed clearly that the lumens of most of the tubules were occluded with mineral crystals in naturally desensitized areas, but such lumens were empty and surrounded with peritubular and intertubular dentin in hypersensitive areas. Moreover, electron-dense structures that lined peritubular dentin were observed in the empty lumens of dentinal tubules

  2. Classification, mechanism and surgical treatments for spinal canal cysts

    Institute of Scientific and Technical Information of China (English)

    Jianjun Sun

    2016-01-01

    A variety of cystic lesions may develop in spinal canal. These cysts can be divided into intramedullary, intradural, extradural, cervical, thoracic, lumbar, and sacral cysts according to anatomical presentation, as well as arachnoid, meningeal, perineural, juxtafacet, discal, neurenteric cysts, and cyst-like lesions according to different etiologies. Mechanisms of initiation and growth vary for different cysts, such as congenital, trauma, bleeding, inflammatory, instability, hydrostatic pressure, osmosis of water, secretion of cyst wall, and one-way-valve effect, etc. Up to now, many treatment methods are available for these different spinal canal cysts. One operation method can be applied in cysts with different types. On the other hand, several operation methods may be utilized in one type of cyst according to the difference of location or style. However, same principle should be obeyed in surgical treatment despite of difference among spinal canal cysts, given open surgery is melely for symptomatic cyst. The surgical approach should be tailored to the individual patient.

  3. Spinal canal stenosis; Spinalkanalstenose

    Energy Technology Data Exchange (ETDEWEB)

    Papanagiotou, P.; Boutchakova, M. [Klinikum Bremen-Mitte/Bremen-Ost, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Bremen (Germany)

    2014-11-15

    Spinal stenosis is a narrowing of the spinal canal by a combination of bone and soft tissues, which can lead to mechanical compression of spinal nerve roots or the dural sac. The lumbal spinal compression of these nerve roots can be symptomatic, resulting in weakness, reflex alterations, gait disturbances, bowel or bladder dysfunction, motor and sensory changes, radicular pain or atypical leg pain and neurogenic claudication. The anatomical presence of spinal canal stenosis is confirmed radiologically with computerized tomography, myelography or magnetic resonance imaging and play a decisive role in optimal patient-oriented therapy decision-making. (orig.) [German] Die Spinalkanalstenose ist eine umschriebene, knoechern-ligamentaer bedingte Einengung des Spinalkanals, die zur Kompression der Nervenwurzeln oder des Duralsacks fuehren kann. Die lumbale Spinalkanalstenose manifestiert sich klinisch als Komplex aus Rueckenschmerzen sowie sensiblen und motorischen neurologischen Ausfaellen, die in der Regel belastungsabhaengig sind (Claudicatio spinalis). Die bildgebende Diagnostik mittels Magnetresonanztomographie, Computertomographie und Myelographie spielt eine entscheidende Rolle bei der optimalen patientenbezogenen Therapieentscheidung. (orig.)

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

    Directory of Open Access Journals (Sweden)

    SH. Kasraei

    2009-06-01

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

  5. A COMPARATIVE EVALUATION OF BOND - STRENGTH BETWEEN NORMAL DENTIN AND CARIES AFFECTED DENTIN: AN INVITRO STUDY

    OpenAIRE

    Arun; Sanjeev; Rohit; De, Asit; Ajay; Kshiti; Harpreet Singh; Farah

    2015-01-01

    INTRODUCTION: The concept of adhesive dentistry has taken leaps forward and has resulted in a concept of more conservation of tooth structure which in turn enhance the life of teeth. The bonding agent forms a hybrid layer with dentin and its other side co - polymerize with the matrix p hase of dental composite, producing strong micro - mechanical bonding. AIMS AND OBJECTIVE: To evaluate the bond strength of adhesive agent to normal dentin and caries affe...

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

    Directory of Open Access Journals (Sweden)

    Atabak Shahidi

    2011-08-01

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

  7. Cytotoxicity of 5% Tamarindus indica extract and 3% hydrogen peroxide as root canal irrigation

    Directory of Open Access Journals (Sweden)

    Erawati Wulandari

    2008-09-01

    Full Text Available Background: Preparation of root canal is an important stage in endodontic treatment. During conducting preparation, it is always be followed with root canal irrigation that has aim to clean root canal from necrotic tissue remains, grind down dentin powder, micro organism, wet the root canal to make preparation process of root canal easier, and solute root canal content at area that can not be reached by equipment. Flesh of Tamarindus indica (pulpa tamarindorum is used as traditional medicine and it contains vitamin C (antioxidant, protein, fat, glucose, etc. Previous research shows that 5% tamarindus indica extract can clean smear layer but it is more cytotoxicity to cell line BHK–21 than sterilized aquabides. Purpose: This research is to compare cytotoxicity between 5% Tamarindus indica extract with 3% H2O2 as root canal irrigation material. Method: Four teen culture cell line BHK 21 divides into 2 groups. Group 1 is treated with 3% H2O2 and Group 2 is treated with 5% Tamarindus indica extract, for about 2.5 minutes in every group. Then, living and death cell percentage is measured. Data is analyzed with independent t test with significant level of 0.05%. Result: The research showed that death cell in group 1 was 29.3% and in group 2 was 21.1%. There was a significant different (p < 0.05 between group 1 and group 2. Conclusion: Cytotoxicity of 5% Tamarindus indica extract to the cell line BHK–21 is lower than 3% H2O2.

  8. Origin and evolution of the canal raphe system in diatoms.

    Science.gov (United States)

    Ruck, Elizabeth C; Theriot, Edward C

    2011-11-01

    One lineage of pennate diatoms has a slit through the siliceous cell wall, called a "raphe," that functions in motility. Raphid pennate diatoms number in the perhaps tens of thousands of species, with the diversity of raphe forms potentially matching this number. Three lineages-the Bacillariales, Rhopalodiales, and Surirellales-possess a complex and presumably highly derived raphe that is physically separated from the cell interior, most often by a set of siliceous braces. Because the relationship among these three lineages is unclear, the number of origins of the canal raphe system and the homology of it and its constitutive parts among these lineages, is equally unclear. We reconstructed the phylogeny of raphid pennate diatoms and included, for the first time, members of all three canal raphid diatom lineages, and used the phylogeny to test specific hypotheses about the origin of the canal raphe. The canal raphe appears to have evolved twice, once in the common ancestor of Bacillariales and once in the common ancestor of Rhopalodiales and Surirellales, which form a monophyletic group in our analyses. These results recommend careful follow-up morphogenesis studies of the canal raphe in these two lineages to determine the underlying developmental basis for this remarkable case of parallel evolution.

  9. Hydrofluoric acid on dentin should be avoided.

    NARCIS (Netherlands)

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

    2010-01-01

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

  10. Dentin Dysplasia in Notum Knockout Mice.

    Science.gov (United States)

    Vogel, P; Read, R W; Hansen, G M; Powell, D R; Kantaputra, P N; Zambrowicz, B; Brommage, R

    2016-07-01

    Secreted WNT proteins control cell differentiation and proliferation in many tissues, and NOTUM is a secreted enzyme that modulates WNT morphogens by removing a palmitoleoylate moiety that is essential for their activity. To better understand the role this enzyme in development, the authors produced NOTUM-deficient mice by targeted insertional disruption of the Notum gene. The authors discovered a critical role for NOTUM in dentin morphogenesis suggesting that increased WNT activity can disrupt odontoblast differentiation and orientation in both incisor and molar teeth. Although molars in Notum(-/-) mice had normal-shaped crowns and normal mantle dentin, the defective crown dentin resulted in enamel prone to fracture during mastication and made teeth more susceptible to endodontal inflammation and necrosis. The dentin dysplasia and short roots contributed to tooth hypermobility and to the spread of periodontal inflammation, which often progressed to periapical abscess formation. The additional incidental finding of renal agenesis in some Notum (-/-) mice indicated that NOTUM also has a role in kidney development, with undiagnosed bilateral renal agenesis most likely responsible for the observed decreased perinatal viability of Notum(-/-) mice. The findings support a significant role for NOTUM in modulating WNT signaling pathways that have pleiotropic effects on tooth and kidney development. PMID:26926082

  11. Creep and Viscoelastic Behaviour of Human Dentin

    Directory of Open Access Journals (Sweden)

    T.Jafarzadeh

    2004-03-01

    Full Text Available Statement of Problem: Biomechanics of the human dentition is inherently complex.Purpose: The aim of this study is to investigate, in vitro, the creep and the recovery of dentin under static uniaxial compressive stress conditions.Materials and Methods: Specimens of cylindrical morphology were prepared from recently extracted non-carious lower molar teeth, such that the average tubule orientation was axial. Slides of mid- coronal dentin (parallel surfaces, height 1.8 mm were sectionedwith a slow speed diamond saw and then cut into cylindrical discs. Specimens were stored at 4ºC for 24h to restabilize water content. Creep data were then measured by LVDT axially in water for periods of 2h load + 2h recovery on 4 separate groups (n=6: at two stresses (10 & 18 MPa and at two temperatures: 37 & 60ºC. Maximum creep strain, permanent set,strain recovery and initial compressive modulus were reported.Results: Compliance values were also calculated and slight non-linearity found at 60ºC.Two-way ANOVA was performed on results. Dentin exhibited a linear viscoelastic response under 'clinical' compressive stress levels , with a maximum strain ~ 1% and highrecoverability: permanent set<0.3%.Conclusion: This established a performance standard for viscoelastic stability of restorative biomaterials, replacing human dentin.

  12. Bonding amalgam to dentin by different methods.

    Science.gov (United States)

    Hadavi, F; Hey, J H; Strasdin, R B; McMeekin, G P

    1994-09-01

    The shear bond strengths of amalgam to dentin by use of (1) All-Bond-2 adhesive, (2) Amalgambond Plus adhesive and (3) TMS Minim pins were compared in this study. Forty-five sound human molars were mounted in acrylic resin and randomly assigned to one of the three groups. The occlusal surfaces were ground to expose the dentin, which was then wet-polished with 600-grit sand paper. All materials were applied according to manufacturer's instructions. A split die with a 5 mm opening was placed and amalgam was condensed, which created an amalgam cylinder bonded/retained to the dentin surface. A shear bond force was applied to the base of the amalgam cylinder. The data were analyzed with analysis of variance and Scheffé's test at the 95% level. All systems were found to promote adhesion/retention of amalgam to dentin. The All-Bond 2 group showed significantly higher bond strength (11.106 +/- 3.585 MPa) than Amalgambond Plus (6.343 +/- 3.564 MPa) and TMS pin (6.868 +/- 0.794 MPa) (p < 0.05). PMID:7965897

  13. Characterization of Genipin-Modified Dentin Collagen

    Directory of Open Access Journals (Sweden)

    Hiroko Nagaoka

    2014-01-01

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

  14. Evaluation of Calcium Phosphate Cement As a Root Canal Sealer Filling Material

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Calcium phosphate cement for root end sealing was obtained by mixing α-tricalcium phosphate and additives with an aqueous solution of citric. Powder and liquid were mixed at a ratio of 1.25g/mL. The biocompatibility of this material was investigated primarily by subcutaneous implantation tests. Then calcium phosphate cement was used to fill three adult dogs' root canal, both calcium hydroxide paste and hydroxyapatite paste as control. The animals were killed at 4,12,20 weeks postoperatively respectively. The effects of different materials on the apical closure, restoration of periapical tissues and adaptability to the dentinal surface were examined by optical and electronic microscope. The observation at 20 weeks shows that the calcium phosphate cement has the potentialities of being a root canal sealer filling material available for pulpless teeth with open-apex and destructive periapical tissue.

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

    International Nuclear Information System (INIS)

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

  16. Extracellular matrix proteins and the dynamics of dentin formation.

    Science.gov (United States)

    Butler, William T; Brunn, Jan C; Qin, Chunlin; McKee, Marc D

    2002-01-01

    Dentinogenesis involves controlled reactions that result in conversion of unmineralized predentin to dentin when apatite crystals are formed. This process is dynamic: Maturation events occur within predentin beginning at the proximal layer and progressing to the predentin-dentin (PD) border. One type of controlled reaction is the proteolytic processing of dentin sialophosphoprotein (DSPP) to dentin sialoprotein (DSP) and dentin phosphoprotein (DPP), by cleavage of at least three highly conserved peptide bonds. We postulate that this processing event represents an activation step, resulting in release of DPP, which is active in its effects on formation and growth of apatite crystals. Dentin matrix protein 1 (DPM1), present as a processed fragment (57-kD protein) in bone, is seen in dentin on sodium dodecyl sulfate polyacrylamide gel electrophoresis as one intact protein of 150-200 kD. Anti-57-kD antibodies elicit immunoreactivity in bone, dentin, and cellular cementum. In bone, the reactivity is associated with osteocytes and their cell processes. Similarly, dentin shows reactivity in odontoblasts, predentin, and the odontoblast processes. In summary, the processing of large sialic acid-rich proteins into smaller fragments may be an important part of the controlled conversion of predentin to dentin and osteoid to bone.

  17. Hood Canal Steelhead - Hood Canal Steelhead Supplementation Experiment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Hood Canal Steelhead Project is a 17-year before-after-control-impact experiment that tests the effects of supplementation on natural steelhead populations in...

  18. Method for Constructing Standardized Simulated Root Canals.

    Science.gov (United States)

    Schulz-Bongert, Udo; Weine, Franklin S.

    1990-01-01

    The construction of visual and manipulative aids, clear resin blocks with root-canal-like spaces, for simulation of root canals is explained. Time, materials, and techniques are discussed. The method allows for comparison of canals, creation of any configuration of canals, and easy presentation during instruction. (MSE)

  19. [External auditory canal osteoma resulting in cholesteatoma which is complicated with meningitis].

    Science.gov (United States)

    Yorgancılar, Ediz; Kınış, Vefa; Gün, Ramazan; Bakır, Salih; Ozbay, Musa; Topçu, Ismail

    2013-01-01

    Osteoma of external auditory canal is a unilateral benign tumor which usually presents with no symptoms. They only cause symptoms when cerumen collection or conduction type hearing loss occurs. They are the most common osseous lesions of the temporal bone. It very rarely presents with cholesteatoma. So far, no osteoma case concomitant with, cholesteatoma and meningitis has not been reported. In this article, we report an interesting case presenting with external auditory canal osteoma, cholestatoma and meningitis concomitantly who was treated successfully using the canal Wall-down mastoidectomy technique.

  20. Health risk assessment for the Building 3001 Storage Canal at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    This human health risk assessment has been prepared for the Environmental Restoration (ER) Program at the Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee. The objectives of this risk assessment are to evaluate the alternatives for interim closure of the Building 3001 Storage Canal and to identify the potential health risk from an existing leak in the canal. The Building 3001 Storage Canal connects Buildings 3001 and 3019. The volume of water in the canal is monitored and kept constant at about 62,000 gal. The primary contaminants of the canal water are the radionuclides 137Cs, 60Co, and 90Sr; a layer of sediment on the canal floor also contains radionuclides and metals. The prime medium of contaminant transport has been identified as groundwater. The primary route for occupational exposure at the canal is external exposure to gamma radiation from the canal water and the walls of the canal. Similarly, the primary exposure route at the 3042 sump is external exposure to gamma radiation from the groundwater and the walls of the sump. Based on the exposure rates in the radiation work permits (Appendix C) and assuming conservative occupational work periods, the annual radiation dose to workers is considerably less than the relevant dose limits. The potential risk to the public using the Clinch River was determined for three significant exposure pathways: ingestion of drinking water; ingestion of contaminated fish; and external exposure to contaminated sediments on the shoreline, the dominant exposure pathway

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

    Directory of Open Access Journals (Sweden)

    Farimah Sardari

    2012-01-01

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

  2. Strain Distribution in Root Surface Dentin of Maxillary Central Incisors during Lateral Compaction

    Science.gov (United States)

    Pilo, Raphael; Metzger, Zvi; Brosh, Tamar

    2016-01-01

    Aim To precisely quantify the circumferential strains created along the radicular dentin of maxillary incisors during a simulated clinical procedure of lateral compaction. Methods Six miniature strain gauges were bonded on the roots of fourteen recently extracted maxillary central incisors that were subjected to root canal instrumentation. The strain gauges were bonded at three levels (apical, middle, and coronal) and four aspects (buccal, lingual, mesial, and distal) of the roots. Each tooth was embedded in a PVC cylinder containing polyvinyl-siloxane impression material. Root filling was then performed by simulating the clinical procedure of lateral compaction using nickel-titanium finger spreaders. The force applied to the spreader and the strains developing in the surface root dentin were continuously recorded at a frequency of 10 Hz. Results The highest strains that developed during lateral compaction were in the mesial and distal aspects at the apical level of the root. The magnitudes of the maximal mesial/distal strains at the apical as well as the mid-root levels were approximately 2.5–3 times higher than those at the buccal/lingual aspects (p = 0.041). The strains decreased significantly (pdentin but decrease gradually to negligible levels. PMID:27227404

  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. PMID:27069484

  4. Quantitative Analysis of Defects at the Dentin-Post Space in Endodontically Treated Teeth

    Directory of Open Access Journals (Sweden)

    Mariasevera Di Comite

    2015-06-01

    Full Text Available The objective of this study was to assess frequency and extension of the defects affecting the dentin-post interface after using different combinations of irrigants and sealers. The experimental work was conducted on single-rooted teeth extracted for orthodontic reasons. The specimens were divided into different groups, according to irrigant and endodontic cement utilized, and endodontically instrumented. After fiberglass posts cementation, cross sections were obtained at apical, middle and coronal level of the root and submitted to quantitative analyses. Different types of defects were found: bubbles, bonding defects, polymerization defect, and cement residues. The percent extension of each defect and its frequency were related to the specific irrigant/sealer combination and to the root level. Detachments of the material from dentin were found only at apical and middle levels. Chlorhexidine digluconate seems to have more beneficial effects if compared to sodium hypochlorite: samples prepared with chlorhexidine digluconate showed a higher performance, with roots including null to few defects. In detail, samples treated with chlorhexidine digluconate and Pulp Canal Sealer showed the lowest frequency and the smallest dimension of defects.

  5. Antibacterial efficacy of Mangifera indica L. kernel and Ocimum sanctum L. leaves against Enterococcus faecalis dentinal biofilm

    Directory of Open Access Journals (Sweden)

    Arunajatesan Subbiya

    2013-01-01

    Full Text Available Introduction: The Enterococcus faecalis biofilm in the root canal makes it difficult to be eradicated by the conventional irrigants with no toxicity to the tissues. Hence, plant products with least side effects are explored for their use as irrigants in the root canal therapy. Aim: To evaluate and compare the antibacterial efficacy of Mangifera indica L. kernel (mango kernel and Ocimum sanctum L. leaves (tulsi extracts with conventional irrigants (5% sodium hypochlorite (NaOCl and 2% chlorhexidine against E. faecalis dentinal biofilm. Materials and Methods: Agar diffusion and broth microdilution assay was performed with the herbal extracts and conventional irrigants (2% chlorhexidine and 5% NaOCl against E. faecalis planktonic cells. The assay was extended onto 3 week E. faecalis dentinal biofilm. Results: Significant reduction of colony forming units (CFU/mL was observed for the herbal groups and the antibacterial activity of the herbal groups was at par with 5% NaOCl. Conclusions: The antibacterial activity of these herbal extracts is found to be comparable with that of conventional irrigants both on the biofilm and planktonic counterparts.

  6. The Love Canal: Beyond science?

    Science.gov (United States)

    Bell, Peter M.

    When in 1978, the New York State Department of Health issued the report, ‘Love Canal—Public Health Time Bomb,’ the serious effects of chemical waste contamination in the Love Canal area became an issue of national concern. A few ‘studies’ since then have produced results in concert with those of initial reports that described ‘conditions of acute health effects’ as being linked to hazardous wastes incorporated in landfill in the Love Canal site near Niagara Falls, New York. Now that a ‘blue ribbon’ panel of experts from the medical sciences has reviewed the problems of Love Canal, however, a different view has emerged. The ‘Report of the Governors' Panel to Review Scientific Studies and the Development of Public Policy on Problems Resulting from Hazardous Wastes,’ transmitted in October of this year, identifies the following factors about the health effects at Love Canal:

  7. Ultrasonic cleaning of root canals

    Science.gov (United States)

    Verhaagen, Bram; Boutsioukis, Christos; Jiang, Lei-Meng; Macedo, Ricardo; van der Sluis, Luc; Versluis, Michel

    2011-11-01

    A crucial step during a dental root canal treatment is irrigation, where an antimicrobial fluid is injected into the root canal system to eradicate all bacteria. Agitation of the fluid using an ultrasonically vibrating miniature file has shown significant improvement in cleaning efficacy over conventional syringe irrigation. However, the physical mechanisms underlying the cleaning process, being acoustic streaming, cavitation or chemical activity, and combinations thereof, are not fully understood. High-speed imaging allows us to visualize the flow pattern and cavitation in a root canal model at microscopic scales, at timescales relevant to the cleaning processes (microseconds). MicroPIV measurements of the induced acoustic streaming are coupled to the oscillation characteristics of the file as simulated numerically and measured with a laser vibrometer. The results give new insight into the role of acoustic streaming and the importance of the confinement for the cleaning of root canals.

  8. Porcine dentin sialoprotein glycosylation and glycosaminoglycan attachments

    Directory of Open Access Journals (Sweden)

    Yamakoshi Fumiko

    2011-02-01

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

  9. Influences of sample preparations on dentine ESR signals

    International Nuclear Information System (INIS)

    The work is to study influences of sample preparations on dentine ESR (electron spin resonance) signals, in order to use dentine samples for dose reconstruction, which has been performed with enamel samples. The dentine and enamel samples were collected from non-irradiated adult teeth and prepared by mechanical or mechanical plus chemical methods. The samples were scanned by an ESR spectrometer before and after their irradiation by 60Co γ-rays. The sensitivities of ESR signals of dentine and enamel samples to irradiation dose differed significantly among different sample preparation methods. The results show that dentine samples mechanically and chemically prepared have good enough ESR response to low dose γ-ray irradiations, and it is possible to use the dentine samples for dose reconstruction, as a substitution to enamel samples when they are short of supply. (authors)

  10. Horizontal Canal Benign Positional Vertigo

    Directory of Open Access Journals (Sweden)

    Mohtaram Najafi

    1998-03-01

    Full Text Available Benign paroxysmal positional vertigo (BPPV is a syndrome characterized by transient episodes of vertigo in association with rapid changes in head position in Dix-Halpike Maneuver. This kind of vertigo is thought to be caused by migration of otoconial debris into canals other than the posterior canal, such as the anterior or lateral canals. It is also theoretically possible for many aberrant patterns of BPPV to occur from an interaction of debris in several canals, location of debris within the canal, and central adaptation patterns to lesions. The symptoms of BPPV are much more consistent with free-moving densities (canaliths in the posterior SCC rather than fixed densities attached to the cupula. While the head is upright, the particles sit in the PSC at the most gravity-dependent position. The best method to induce and see vertigo and nystagmus in BPPV of the lateral semicircular canal is to rotate head 90°while patient is in the supine position, nystagmus would appear in the unaffected side weaker but longer than the affected side. canal paresis has been described in one third of the patients with BPPV. Adaptation which is one of the remarkable features of BPPV in PSC is rarely seen in LSC. Rotations of 270° or 360° around the yaw axis (the so-called barbecue maneuver toward the unaffected ear are popular methods for the treatment of geotropic HC-BPPV. These maneuvers consist of sequential head turning of 90° toward the healthy side while supine. With these maneuvers, the free-floating otoconial debris migrates in the ampullofugal direction, finally entering the utricle through the nonampullated end of the horizontal canal. This kind of vertigo recovers spontaneously more rapidly and suddenly.

  11. Microtensile Bond Strength of Cad-Cam and Pressed-Ceramic Inlays to Dentin

    Science.gov (United States)

    Öztürk, A. Nilgün; İnan, Özgür; İnan, Erkan; Öztürk, Bora

    2007-01-01

    Objectives CAD-CAM system is popular because of high esthetic and short fabrication time. But, there is limited information available about the microtensile bonding of luting cements to CAD-CAM inlays and to dentin. The aim of this study was to examine the bond strength of CAD-CAM (Cerec 3) and pressed-ceramic (IPS Empress 2) inlays to dentin surface by microtensile testing using two luting cements. Materials and Methods Standardized mesio-occlusal cavities were made in forty extracted molar teeth. An occlusal reduction of 2 mm was made; the bucco-lingual width of the proximal boxes was 4 mm, the occlusal width 3 mm and the depth of the pulpal and axial walls 2 mm. The proximal boxes were extended 1 mm below the cemento-enamel junction. Teeth were randomly assigned to 2 groups to evaluate the bonding of 2 ceramic systems, Cerec 3 (Group I) and IPS Empress 2 (Group II), to dentin. Each of the 2 groups were further divided into 2 luting cement groups, Panavia F (Group A) and Variolink II (Group B). After cementation, the teeth were sectioned into two 1.2x1.2 mm wide ‘I’ shape sections. The specimens were then subjected to microtensile testing at a crosshead speed of 1 mm/min. Two-way ANOVA and Tukey HSD tests were used to evaluate the results. Results The mean microtensile bond strengths of Cerec 3 and IPS Empress 2 bonding to dentin with luting agents in MPa were Panavia F (13.98±3.44), Variolink II (14.19±3.12) and Panavia F (15.12±3.15), Variolink II (15.45±3.08) respectively. No significant differences were found among the 2 ceramic systems (P>.05) and 2 luting cements with regard to dentin bond strengths (P>.05). Conlusions There was no difference found between the dentin bond strength of the Cerec 3 and IPS Empress 2 inlays cemented with two luting cements. PMID:19212483

  12. Dentin phosphoprotein compound mutation in dentin sialophosphoprotein causes dentinogenesis imperfecta type III.

    Science.gov (United States)

    Dong, Juan; Gu, TingTing; Jeffords, Leticia; MacDougall, Mary

    2005-01-30

    A rare compound mutation involving a 36 bp deletion and 18 bp insertion within exon 5 of the dentin sialophosphoprotein (DSPP) gene has been identified in a family with dentinogenesis imperfecta type III (DGI-III). The DSPP gene encodes two major tooth matrix proteins dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). DSPP mutations associated with DGI-III results in an in frame truncation of the serine aspartic acid triplet repeat found in DPP near the highly conserved carboxyl terminal region shortening the protein by six amino acids. Clinically this family presents with discolored amber opalescent teeth and severe attrition of the tooth structure. This study is the first report of a mutation within DPP associated with a genetic dentin disease. Our study indicates that DGI-III is allelic with some forms of DGI-II with and without progressive hearing loss and dentin dysplasia type II that have been shown to be caused by mutations within the DSP coding or signal peptide regions.

  13. Efficacy of various root canal irrigants on removal of smear layer in the primary root canals after hand instrumentation: A scanning electron microscopy study

    Directory of Open Access Journals (Sweden)

    Hariharan V

    2010-01-01

    Full Text Available Aim: The purpose of this in-vitro study is to determine the efficacy of various irrigants in removing the smear layer in primary teeth root canals after hand instrumentation. Materials and Methods: The present study consisted of 30 human primary incisors which were sectioned at the cementoenamel junction horizontally. The specimens were divided randomly into four experimental and one control group having six teeth each and each group was treated with the specific irrigant. 5.25% NaOCl, 5.25% NaOCl + 10% EDTA, 6% citric acid, 2% chlorhexidine, saline (control were the irrigants evaluated for efficacy in removal of smear layer. The specimens were split along the longitudinal axis using a chisel after placing superficial grooves in cementum not extending to the root canal. The exposed surface was subjected to scanning electron microscopic analysis to reveal the efficacy of irrigants in removal of smear layer. The representative areas were evaluated twice at 15 days interval by a single evaluator. The scale for the smear layer removal by Rome et al was modified and used in the present study. Results: The pictures from the scanning electron microscopy showed that among the tested irrigants, citric acid has the best efficacy to remove the smear layer without altering the normal dentinal structures, which was supported by the lowest mean smear scores. The pictures from the 10%EDTA + 5.25% sodium hypochlorite group showed that even though it removed the smear layer, it adversely affected the dentine structure. SEM pictures of the other groups like sodium hypochlorite, chlorhexidine revealed that these irrigants does not have the capacity to remove the smear layer in primary teeth. Conclusions: The results of the present study clearly indicate the superior efficacy of 6% citric acid than the other tested irrigants on removing the smear layer in primary teeth root canals.

  14. Bahan-Bahan Pembentuk Dentin Sekunder Dalam Bidang Kedokteran Gigi

    OpenAIRE

    Ahmad Fauzi M.

    2008-01-01

    Sepanjang hidup, selama pulpa masih vital, dentin sekunder terbentuk secara teratur pada tepi pulpa, hal ini merupakan fungsi formatif pulpa yaitu jaringan pulpa mampu mengadakan reparasi dalam menanggulangi cedera yang diterima. Dentin sekunder yang dibentuk berfungsi dalam hal pertahanan diri terhadap efek atrisi, karies gigi, trauma, dan mengurangi masuknya iritan. Bahan-bahan pembentuk dentin sekunder dapat digunakan pada keadaan dimana jaringan pulpa tidak mampu lagi mengadakan repa...

  15. The everyday impact of dentine sensitivity: personal and functional aspects

    OpenAIRE

    Gibson, B.; BOIKO O.V.; S. Baker; Robinson, P G; Barlow, A.; Player, T.; Locker, D

    2010-01-01

    Research into oral health status and the impact of oral conditions on everyday life has been developed over the last 30 years. To date it is not clear the degr ee to which these measures can be applied to the pr oblems and impacts associated with dentine sensitivity. Th ere has been very little research on the everyday i mpact of dentine sensitivity. The aim of this study was t o explore the everyday experiences of dentine sensi tivity; in particular ...

  16. The effect of rotary instrumentation on the permeability of dentin

    International Nuclear Information System (INIS)

    The filtration and diffusion of tritiated water through dentin disks were measured ina split-chamber diffusion cell. The dentin had been cut with a diamond disk and the surfaces modified with a carbide fissure bur or diamond bur. Disks were given a secondary burnishing treatment with a blank bur or a modified blank bur. Burnishing reduced the permeability of dentin cut with a fissure bur

  17. Is bovine dentine an appropriate substitute in abrasion studies

    OpenAIRE

    Wegehaupt, F J; Widmer, R.; Attin, T.

    2010-01-01

    The study aimed to compare the wear behaviour of human and bovine dentine due to toothbrushing with different relative dentin abrasivity (RDA) toothpastes. Forty human and 40 bovine dentine samples were prepared from bovine lower incisors or human premolars roots, and baseline surface profiles were recorded. The samples were distributed to four groups (each group n = 10 human and 10 bovine samples) and brushed with fluoridated experimental toothpastes with different RDAs (group A: RDA 10, B: ...

  18. A technical report on repair of amalgam-dentin complex

    OpenAIRE

    Özcan, M; Salihoğlu-Yener, E

    2011-01-01

    This clinical report describes a repair protocol for cusp fracture of a failed amalgam-dentin complex. A maxillary right first premolar with an amalgam restoration presented a buccal cusp fracture. Chairside repair has been undertaken by conditioning the existing amalgam restoration with silica coating (30 μm CoJet®-Sand), phosphoric acid etching the beveled enamel surface, priming dentin, and application of a bonding agent on both enamel and dentin. Thereafter, the amalgam was silanized (ESP...

  19. Shear bond strength of partial coverage restorations to dentin

    OpenAIRE

    Román Rodríguez, Juan Luis; Agustín Panadero, Rubén; Alonso Pérez Barquero, Jorge; Fons Font, Antonio; Solá Ruiz, María Fernanda

    2015-01-01

    Background When partial coverage restorations (veneers, inlays, onlays…) must be cemented to dentin, bond strength may not reach the same predictable values as to enamel. The purpose of this study was: 1. To compare, with a shear bond test, the bond strength to dentin of a total-etch and a self-etching bonding agent. 2. To determine whether creating microretention improves the bond strength to dentin. Material and Methods Two bonding agents were assayed, Optibond FL® (Kerr), two-bottle adhesi...

  20. Morphological effects of MMPs inhibitors on the dentin bonding

    OpenAIRE

    Li, He; Li, Tianbo; Li, Xiuying; Zhang, Zhimin; Li, Penglian; Li, Zhenling

    2015-01-01

    Matrix metalloproteinases (MMPs) have been studied extensively, and MMP inhibitors have been used as dental pretreatment agents prior to dentin bonding because they reduce collagen fiber degradation and improve bonding strength. However, morphologic characteristics of the collagen network after etching and of the post-adhesive dentin hybrid layers (DHL) after MMP inhibitors pretreatment have not been evaluated. Thus, we investigated demineralized dentin pretreated with chlorhexidine (CHX) and...

  1. Dentin hassasiyeti ve tedavi yöntemleri

    OpenAIRE

    Atilla Berberoglu; Esra Cengiz; Hakan Bayindir; Hasan Güney Yilmaz

    2012-01-01

    Dentin hypersensitivity (DH) is a relatively common problem experienced in clinical dental practice. This condition has been defined as a short, sharp pain arising from exposed dentin in response to stimuli typically thermal, evaporative, tactile, osmotic or chemical and which cannot be described to any other form of dental defect or pathology. DH may ocur as a result of exposed dentinal tubules through either loss of enamel or gingival recession. Management strategies, which take in...

  2. Effect of ethylene diamine tetra-acetic acid, MTAD TM , and HEBP as a final rinse on the microhardness of root dentin

    Directory of Open Access Journals (Sweden)

    Mukura Kulasekaran Dineshkumar

    2012-01-01

    Aims: This study evaluated the effect of 17% EDTA, MTAD, and 18% HEBP solutions on the microhardness of human root canal dentin using the Vickers microhardness test. Materials and Methods: Forty human single-rooted teeth were decoronated at the cementoenamel junction and sectioned longitudinally into buccal and lingual segments. Eighty specimens were divided into four groups (n=20. Group I was treated with distilled water (control, groups II, III, and IV were treated with 1.3% NaOCl as a working solution for 20 minutes followed by 17% EDTA, MTAD, and 18% HEBP respectively. The surface hardness of the root dentin was determined in each specimen with a Vicker′s hardness tester. The values were statistically analyzed using the one-way ANOVA and post hoc Tukey multiple comparison tests. Results: There was a statistical significant difference among all the groups (one-way ANOVA; P<0.001. Among the experimental groups, HEBP showed the highest dentin microhardness (53.74 MPa, P<0.001. Least microhardness was found with MTAD (42.85 MPa, P<0.001. Conclusions: HEBP as a final rinse appears to be a promising irrigation protocol with less impact on the mineral content of root dentin.

  3. A Stereomicroscopic Evaluation of Dentinal Cracks at Different Instrumentation Lengths by Using Different Rotary Files (ProTaper Universal, ProTaper Next, and HyFlex CM: An Ex Vivo Study

    Directory of Open Access Journals (Sweden)

    Fauzia Ashraf

    2016-01-01

    Full Text Available Introduction. The aim of the present study was to evaluate the dentinal cracks after root canal preparation with rotary files: Gates Glidden, ProTaper Universal, ProTaper Next, and HyFlex CM at different instrumentation lengths. Methodology. Sixty-five mandibular premolars were mounted in the acrylic tube with simulated periodontal ligaments and the apex was exposed. The root canals were instrumented with different rotary files, namely, ProTaper Universal, ProTaper Next, and HyFlex CM, to the major apical foramen (AF, short AF, and beyond AF. The root apex was stained with 1% methylene blue dye and digital images of apical surface of every tooth were taken and development of dentinal defects was determined by using stereomicroscope. Multinomial logistic regression test was performed to identify influencing factors. Results. Instrumentation with rotary files terminated 2 mm short AF and did not cause any cracks. Significantly less cracks were seen when instrumentation with rotary files terminated 1 mm short apical foramen when compared with the instrumentation terminated at or beyond apical foramen (p<0.05. Conclusion. ProTaper Universal rotary files caused more dentinal cracks than ProTaper Next and HyFlex CM. Instrumentation short AF reduced the risk of dentinal defects.

  4. A Stereomicroscopic Evaluation of Dentinal Cracks at Different Instrumentation Lengths by Using Different Rotary Files (ProTaper Universal, ProTaper Next, and HyFlex CM): An Ex Vivo Study

    Science.gov (United States)

    Shankarappa, Pushpa; Misra, Abhinav; Sawhney, Asheesh; Sridevi, Nandamuri; Singh, Anu

    2016-01-01

    Introduction. The aim of the present study was to evaluate the dentinal cracks after root canal preparation with rotary files: Gates Glidden, ProTaper Universal, ProTaper Next, and HyFlex CM at different instrumentation lengths. Methodology. Sixty-five mandibular premolars were mounted in the acrylic tube with simulated periodontal ligaments and the apex was exposed. The root canals were instrumented with different rotary files, namely, ProTaper Universal, ProTaper Next, and HyFlex CM, to the major apical foramen (AF), short AF, and beyond AF. The root apex was stained with 1% methylene blue dye and digital images of apical surface of every tooth were taken and development of dentinal defects was determined by using stereomicroscope. Multinomial logistic regression test was performed to identify influencing factors. Results. Instrumentation with rotary files terminated 2 mm short AF and did not cause any cracks. Significantly less cracks were seen when instrumentation with rotary files terminated 1 mm short apical foramen when compared with the instrumentation terminated at or beyond apical foramen (p < 0.05). Conclusion. ProTaper Universal rotary files caused more dentinal cracks than ProTaper Next and HyFlex CM. Instrumentation short AF reduced the risk of dentinal defects.

  5. Wall-lesion development in gaps: The role of the adhesive bonding material

    NARCIS (Netherlands)

    Montagner, A.F.; Kuper, N.K.; Opdam, N.J.M.; Bronkhorst, E.M.; Cenci, M.S.; Huysmans, M.C.D.N.J.M.

    2015-01-01

    OBJECTIVES: This study evaluated the caries wall lesion development in different composite-dentin interfaces to investigate if the presence and location of two bonding materials in the gaps influence wall caries lesion development. METHODS: Fourteen volunteers wore a modified occlusal splint contain

  6. Bactericidal effect of the 908 nm diode laser on Enterococcus faecalis in infected root canals

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    Thomas Preethee

    2012-01-01

    Full Text Available Aim: The aim of this study is to evaluate the bactericidal effect of 908 nm diode laser in conjunction with various irrigation regimes in disinfection of apical third of root dentin. Materials and Methods: Sixty prepared teeth with single canals were contaminated with Enterococcus faecalis. The specimens were divided into 6 groups (n = 10: Group 1 and 3 and 5 were subjected to chemo-mechanical preparation using 5.25% sodium hypochlorite (NaOCl, 17% Ethylenediaminetetraacetic acid (EDTA; 1.3% NaOCl, MTAD (mixture of doxycycline, citric acid and a detergent (Tween 80; and, 8.5% saline, respectively followed by 908 nm diode laser irradiation; Group 2 and 4, followed the same procedure as Group1 and 3, however without laser irradiation; and, Group 6, rinsed with saline solution (control. Dentin shavings from apical third were analyzed for the presence of E. faecalis using culture method and Polymerase Chain reaction (PCR. Results: One-way Analysis of variance showed statistically significant differences between the laser irradiated groups, non irradiated groups and the control group. Conclusion: 908 nm diode used in conjunction with conventional chemomechanical techniques demonstrated a significant elimination of E. faecalis in the apical third of root dentin.

  7. Native and short-life signals in dentine EPR spectrum

    International Nuclear Information System (INIS)

    In this paper two aspects of dentine based dosimetry are investigated, namely the comparison of dentine and enamel native signal and the stability of the EPR spectrum after irradiation. Native signal intensity of dentine and enamel was found to be of the same order of the magnitude, suggesting that the origin of the native signal is not completely related to the total amount of organic component. Post-irradiation short life signals, with half-life of approximately 10 h, were observed. These signals are similar to those observed shortly after irradiation in enamel and after mechanical treatment in dentine

  8. Native and short-life signals in dentine EPR spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Onori, S.; De Coste, V. [Istituto Superiore di Sanita, Department of Technology and Health, and Istituto Nazionale di Fisica, Nucleare, Rome (Italy); Fattibene, P. [Istituto Superiore di Sanita, Department of Technology and Health, and Istituto Nazionale di Fisica, Nucleare, Rome (Italy)], E-mail: paola.fattibene@iss.it; La Civita, S. [Istituto Superiore di Sanita, Department of Technology and Health, and Istituto Nazionale di Fisica, Nucleare, Rome (Italy)

    2008-02-15

    In this paper two aspects of dentine based dosimetry are investigated, namely the comparison of dentine and enamel native signal and the stability of the EPR spectrum after irradiation. Native signal intensity of dentine and enamel was found to be of the same order of the magnitude, suggesting that the origin of the native signal is not completely related to the total amount of organic component. Post-irradiation short life signals, with half-life of approximately 10 h, were observed. These signals are similar to those observed shortly after irradiation in enamel and after mechanical treatment in dentine.

  9. The Crystal Characteristics of Enamel and Dentin by XRD Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Crystal characteristics of tooth enamel and dentin were investigated using XRD, SEM, and EPMA methods.The results show that the mineral phase in enamel is HA and in dentin is HA and minor whitlock ites.The dentin HA and the enamel HA have different crystallinity, the crystallinity of enamel HA is much higher than that of dentin HA.The average particle size of the enamel HA and dentin HA are 897A and 309A, respectively.The HA in enamel is regularly arranged, and in dentin the arrangement of HA is diifferent from the enamel HA in the same section.Both the enamel and the dentin are mainly consisted of Ca, P, O, and C, and the trace elements Mg , Sr, Al, Na , and K.The dentin contains more trace elements than the enamel.However,the incorporation of trace elements in both dentin and enamel are very limited.Other impurities such as F and Cl are less than their detection limit.The a and c values of enamel HA are 9.433A and 6.8A, and those of thedentin HA are 9.498A and 6.896A, respectively.The expansion in a value results from those the larger size of [CO3 ]2 group substituing for the smaller [ OH]- group in the channel, and replacement of [ OH ]- by[ CO3 ]2- dominates the change in cell parameter, taking into account of other trace elements.

  10. Photosensitizer and light diffusion through dentin in photodynamic therapy

    Science.gov (United States)

    Nogueira, Ana C.; Graciano, Ariane X.; Nagata, Juliana Y.; Fujimaki, Mitsue; Terada, Raquel S. S.; Bento, Antonio C.; Astrath, Nelson G. C.; Baesso, Mauro L.

    2013-05-01

    Photodynamic therapy has been considered a potential antimicrobial modality against oral infections, including dental caries. A model to estimate the penetration of both photosensitizers and light through human dentin, a factor of interest in photodynamic therapy, is proposed. The photoacoustic spectroscopy technique was used to evaluate in vitro dentin permeability of three different photosensitizers. Using the dentin optical absorption and scattering coefficients, it was possible to propose a semi-quantitative model predicting both photosensitizer and light doses within dentin. The graphic illustrations obtained provided guidelines that may be useful in photodynamic therapy protocols used as antimicrobial tools in caries lesions.

  11. A Mechanistic study of Plasma Treatment Effects on Demineralized Dentin Surfaces for Improved Adhesive/Dentin Interface Bonding

    Science.gov (United States)

    Dong, Xiaoqing; Chen, Meng; Wang, Yong; Yu, Qingsong

    2014-01-01

    Our previous work has shown that non-thermal plasma treatment of demineralized dentin significantly (p<0.05) improved adhesive/dentin bonding strength for dental composite restoration as compared with the untreated controls. This study is to achieve mechanistic understanding of the plasma treatment effects on dentin surface through investigating the plasma treated dentin surfaces and their interaction with adhesive monomer, 2-Hydroxyethyl methacrylate (HEMA). The plasma treated dentin surfaces from human third molars were evaluated by water contact angle measurements and scanning electron microscopy (SEM). It was found that plasma-treated dentin surface with subsequent HEMA immersion (Plasma/HEMA Treated) had much lower water contact angle compared with only plasma-treated (Plasma Treated) or only HEMA immersed (HEMA Treated) dentin surfaces. With prolong water droplet deposition time, water droplets spread out completely on the Plasma/HEMA Treated dentin surfaces. SEM images of Plasma/HEMA Treated dentin surfaces verified that dentin tubules were opened-up and filled with HEMA monomers. Extracted type I collagen fibrils, which was used as simulation of the exposed dentinal collagen fibrils after acid etching step, were plasma treated and analyzed with Fourier transform infrared spectroscopy (FT-IR) and circular dichroism (CD) spectra. FT-IR spectra of the Plasma/HEMA Treated collage fibrils showed broadened amide I peak at 1660 cm−1 and amide II at 1550 cm−1, which indicate secondary structure changes of the collagen fibrils. CD spectra indicated that 67.4% collagen helix structures were denatured after plasma treatment. These experimental results demonstrate that non-thermal argon plasma treatment was very effective in loosing collagen structure and enhancing adhesive monomer penetration, which are beneficial to thicker hybrid layer and longer resin tag formation, and consequently enhance adhesive/dentin interface bonding. PMID:25267936

  12. 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.

  13. Dentin hypersensitivity: Recent trends in management.

    Science.gov (United States)

    Miglani, Sanjay; Aggarwal, Vivek; Ahuja, Bhoomika

    2010-10-01

    Dentinal hypersensitivity (DH) is a common clinical condition usually associated with exposed dentinal surfaces. It can affect patients of any age group and most commonly affects the canines and premolars of both the arches. This article concisely reviews the patho-physiology, mechanism and clinical management of the DH. Treatment of DH should start with an accurate diagnosis. Differential diagnosis should be made and all other probable causes should be excluded. An often neglected phase of clinical management of DH is the identification and treatment of the causative factors of DH. By removing the etiological factors, the condition can be even prevented from occurring or recurring. There are various treatment modalities available which can be used at home or may be professionally applied. The "at home" desensitizing agents include toothpastes, mouthwashes or chewing gums and they act by either occluding the dentinal tubules or blocking the neural transmission. This article also discusses the recent treatment options like bioglass, Portland cement, lasers and casein phosphopeptide. PMID:21217949

  14. Diagnosis and treatment of dentinal hypersensitivity.

    Science.gov (United States)

    Porto, Isabel C C M; Andrade, Ana K M; Montes, Marcos A J R

    2009-09-01

    This bibliographic review provides a general view of the etiology, characteristics and treatment of dentinal hypersensitivity, so that professionals can use this information in the therapeutic management of this clinical condition. For this purpose, the authors have analyzed whole texts of relevant articles on the subject. This study showed that the predisposing factors associated with the causes of dentinal hypersensitivity must be controlled or eliminated, by educating the patient regarding the excessive intake of acidic food, as well as providing guidance on the proper tooth brushing technique and analysis of occlusion. Effective treatment must be preceded by a proper diagnosis, established after the exclusion of any other possible causes of the pain. These cases must be managed efficiently, quickly and permanently. The availability of a wide variety of treatment could be an indicator that there is still no effective desensitizing agent to completely resolve the patient's discomfort, or that it is difficult to treat, irrespective of the available treatment options. Even with the large number of published studies, it has not been possible to reach a consensus about the product that represents the gold standard in the treatment of dentinal hypersensitivity. PMID:19776498

  15. Dentin hypersensitivity: Recent trends in management

    Directory of Open Access Journals (Sweden)

    Miglani Sanjay

    2010-01-01

    Full Text Available Dentinal hypersensitivity (DH is a common clinical condition usually associated with exposed dentinal surfaces. It can affect patients of any age group and most commonly affects the canines and premolars of both the arches. This article concisely reviews the patho-physiology, mechanism and clinical management of the DH. Treatment of DH should start with an accurate diagnosis. Differential diagnosis should be made and all other probable causes should be excluded. An often neglected phase of clinical management of DH is the identification and treatment of the causative factors of DH. By removing the etiological factors, the condition can be even prevented from occurring or recurring. There are various treatment modalities available which can be used at home or may be professionally applied. The "at home" desensitizing agents include toothpastes, mouthwashes or chewing gums and they act by either occluding the dentinal tubules or blocking the neural transmission. This article also discusses the recent treatment options like bioglass, Portland cement, lasers and casein phosphopeptide.

  16. Dentin matrix protein 1 and dentin sialophosphoprotein in human sound and carious teeth: an immunohistochemical and colorimetric assay

    Directory of Open Access Journals (Sweden)

    D. Martini

    2013-10-01

    Full Text Available Dentin matrix protein 1 (DMP1 and dentin sialophosphoprotein (DSPP are extracellular matrix proteins produced by odontoblasts involved in the dentin mineralization. The aim this study was to compare the distribution of DMP1 and DSPP in human sound dentin vs human sclerotic dentin. Sixteen sound and sixteen carious human molars were selected, fixed in paraformaldehyde and processed for immunohistochemical detection of DMP1 and DSPP by means of light microscopy, transmission electron microscopy (TEM and high-resolution field emission in-lens scanning electron microscopy (FEI-SEM. Specimens were submitted to a pre-embedding or a post-embedding immunolabeling technique using primary antibodies anti DMP1 and anti-DSPP and gold-conjugated secondary antibodies. Other samples were processed for the detection of DMP1 and DSPP levels. Dentin from these samples was mechanically fractured to powder, then a protein extraction and a protein level detection assay were performed. DMP1 and DSPP were more abundant in carious than in sound samples. Immunohistochemical analyses in sclerotic dentin disclosed a high expression of DMP1 and DSPP inside the tubules, suggesting an active biomineralization of dentin by odontoblasts. Furthermore, the detection of small amounts of these proteins inside the tubules far from the carious lesion, as shown in the present study, is consistent with the hypothesis of a preventive defense of all dentin after a noxious stimulus has undermined the tooth.

  17. Dentin matrix protein 1 and dentin sialophosphoprotein in human sound and carious teeth: an immunohistochemical and colorimetric assay.

    Science.gov (United States)

    Martini, D; Trirè, A; Breschi, L; Mazzoni, A; Teti, G; Falconi, M; Ruggeri, A

    2013-10-29

    Dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein (DSPP) are extracellular matrix proteins produced by odontoblasts involved in the dentin mineralization. The aim this study was to compare the distribution of DMP1 and DSPP in human sound dentin vs human sclerotic dentin. Sixteen sound and sixteen carious human molars were selected, fixed in paraformaldehyde and processed for immunohistochemical detection of DMP1 and DSPP by means of light microscopy, transmission electron microscopy (TEM) and high-resolution field emission in-lens scanning electron microscopy (FEI-SEM). Specimens were submitted to a pre-embedding or a post-embedding immunolabeling technique using primary antibodies anti DMP1 and anti-DSPP and gold-conjugated secondary antibodies. Other samples were processed for the detection of DMP1 and DSPP levels. Dentin from these samples was mechanically fractured to powder, then a protein extraction and a protein level detection assay were performed. DMP1 and DSPP were more abundant in carious than in sound samples. Immunohistochemical analyses in sclerotic dentin disclosed a high expression of DMP1 and DSPP inside the tubules, suggesting an active biomineralization of dentin by odontoblasts. Furthermore, the detection of small amounts of these proteins inside the tubules far from the carious lesion, as shown in the present study, is consistent with the hypothesis of a preventive defense of all dentin after a noxious stimulus has undermined the tooth.

  18. Non-destructive, preclinical evaluation of root canal anatomy of human teeth with flat-panel detector volume CT (FD-VCT)

    International Nuclear Information System (INIS)

    Purpose: Successful endodontic diagnostics and therapy call for adequate depiction of the root canal anatomy with multimodal diagnostic imaging. The aim of the present study is to evaluate visualization of the endodont with flat-panel detector volume CT (FD-VCT). Materials and methods: 13 human teeth were examined with the prototype of a FD-VCT. After data acquisition and generation of volume data sets in volume rendering technology (VRT), the findings obtained were compared to conventional X-rays and cross-section preparations of the teeth. Results: The anatomical structures of the endodont such as root canals, side canals and communications between different root canals as well as dentricles could be detected precisely with FD-VCT. The length of curved root canals was also determined accurately. The spatial resolution of the system is around 140 μm. Only around 73% of the main root canals detected with FD-VCT and 87% of the roots could be visualized with conventional dental X-rays. None of the side canals, shown with FD-VCT, was detectable on conventional X-rays. In all cases the enamel and dentin of the teeth could be well delineated. No differences in image quality could be discerned between stored and freshly extracted teeth, or between primary and adult teeth. (orig.)

  19. The role of perilymph in the response of the semicircular canals to angular acceleration. [dynamic model for perilymph induced displacement of cupula

    Science.gov (United States)

    Anliker, M.; Vanbuskirk, W.

    1973-01-01

    A new model for the response of the semicircular canals to angular motion is postulated. This model is based on evidence that the bony canal is not compartmentalized and assumes that the ampulla wall is highly flexible. It is shown that the perilymph induces a cupula displacement far greater than that produced by the endolymph alone. The predicted dynamic behavior of the canals on the basis of this model is found to be consistent with experimental observations.

  20. RETRATAMENTO ENDODÔNTICO: ESTUDO COMPARATIVO ENTRE TÉCNICA MANUAL, ULTRA-SOM E CANAL FINDER ENDODONTIC RETREATMENT: COMPARATIVE STUDY BETWEEN MANUAL TECHNIQUE, ULTRASONIC SCALER, AND CANAL FINDER

    Directory of Open Access Journals (Sweden)

    Clovis Monteiro BRAMANTE

    1998-01-01

    Full Text Available Instrumentações manual, ultra-sônica e com Canal Finder foram utilizadas para retratamento de 30 dentes com canais obturados com guta-percha e óxido de zinco e eugenol. Avaliaram-se: 1. tempo gasto para a penetração inicial até o ápice; 2. tempo para completar a limpeza; 3. extrusão de material e 4. limpeza dos canais. O Canal Finder foi a técnica que propiciou melhor limpeza, seguida da manual e da ultra-sônica. A parede palatina do canal foi constantemente mais limpa do que a vestibular. Quanto à extrusão, a técnica de ultra-som foi a que propiciou mais extravasamento de material obturador.Endodontic retreatment of 30 teeth filled with guta percha and zinc oxide-eugenol was carried out using manual instrumentation, ultrasonic scaler, and the Canal Finder System. The following variables were evaluated: time spent to reach the apex; time spent to complete cleaning of the canal; apical extrusion of material; and cleanliness of the canals. Results showed the Canal Finder System as providing the highest level of cleanliness of the canal system; lingual walls were constantly cleaner than buccal walls; ultrasonic technique presented a greater degree of apical extrusion of filling material.

  1. Penetração intratubular de cimentos endodônticos Intratubular penetration of root canal sealers

    Directory of Open Access Journals (Sweden)

    Gustavo de Deus

    2002-12-01

    Full Text Available Este estudo foi desenvolvido para avaliar a capacidade de penetração de diferentes cimentos endodônticos (Endo Fill, Sealapex, AH Plus e Pulp Canal Sealer nos túbulos dentinários em dentes devidamente modelados e obturados. Foram utilizados 72 incisivos centrais superiores, os quais foram instrumentados no sentido coroa-ápice pela técnica de forças balanceadas. O comprimento de trabalho foi estabelecido a 1 mm do ápice radicular. Durante a limpeza e modelagem, todos os dentes foram irrigados com 10 ml de hipoclorito de sódio a 5,25%. Os dentes foram divididos em 4 grupos, sendo 1 para cada tipo de cimento. Estes grupos foram então subdivididos em função do uso ou não de EDTA a 17% previamente à obturação dos canais radiculares, para a remoção da lama dentinária. Todos os dentes foram obturados pela técnica da onda de condensação com cone médio calibrado. Após obturação, as raízes foram seccionadas no sentido mésio-distal e foi escolhida a secção de melhor qualidade visual. Estas foram então analisadas em microscopia eletrônica de varredura (MEV, sendo o foco de observação sempre a interface dentina/material obturador. Após obtenção das imagens, mensurou-se os prolongamentos dos cimentos para o interior dos túbulos dentinários. O cimento de Rickert (Pulp Canal Sealer apresentou a maior capacidade de penetração nos túbulos dentinários, sendo os piores resultados apresentados pelo grupo em que se utilizou o Sealapex. Os resultados foram avaliados estatisticamente pelo teste de Spearman, o qual mostrou diferença estatisticamente significante (p The purpose of this study was to evaluate the capacity of penetration of four endodontic sealers (Endo Fill, Sealapex, AH Plus and Pulp Canal Sealer into dentinal tubules. Seventy-two extracted human maxillary anterior teeth were utilized in this study. The teeth were cleaned and shaped by means of the balanced-forces technique. The work length was established at 1

  2. Bacterial penetration of the root canal of intact incisor teeth after a simulated traumatic injury.

    Science.gov (United States)

    Love, R M

    1996-12-01

    One of the aims in treating traumatised teeth is to maintain the vitality of the pulp or allow conditions favourable for pulp revascularisation. However, infection of the pulp and root canal system may prevent this. A number of pathways have been proposed that allow bacteria to invade the root canal system, however most of these pathways cannot account for pulp infection in teeth that did not sustain injury to the periodontal attachment. Enamel/dentine cracks have been proposed as a portal for bacterial invasion of seemingly intact teeth and the aim of this study was to determine if bacteria could invade the root canal system after a simulated traumatic episode. Twenty intact and sound upper central incisors were chosen and prepared. One tooth was selected as a sterility control and the external crown surface of the remaining 19 teeth was subjected to infection with Streptococcus gordonii in a bacterial microleakage model. Over 7 days samples of growth media from the root canal system were taken and tested for bacteria. Sixteen of the teeth did not demonstrate bacterial invasion over the time frame. These teeth were then prepared for testing in a pendulum impact device and were subjected to a blow which did not fracture the crowns or dislodge the tooth from its simulated alveolus. The teeth were then prepared and tested in the bacterial microleakage model. After impact seven of the teeth demonstrated bacterial invasion of the root canal system (P = 0.002). These teeth were then reprepared for testing in the bacterial microleakage model. The crowns of five teeth, selected at random, were coated with two layers of light cured unfilled resin, the remaining two were used as positive controls. All the teeth coated with resin did not demonstrate bacterial invasion (P = 0.00), while the positive controls demonstrated invasion. The results suggested that enamel/dentine infractions were pathways for bacterial invasion of the root canal system of traumatised teeth. The

  3. Exposure and direct stimulation of the semicircular canal cupula.

    Science.gov (United States)

    Suzuki, M; Harada, Y

    1985-01-01

    The ampullary wall of the posterior semicircular canal was isolated from the frog, cut and the cupula exposed in frog Ringer's solution. The cupula was stimulated by depression with a fine glass micropipette. Three points on the cupula were selected for depression: point A, the lowest point on the midline of the cupula surface on the utricular side; point B, the uppermost on the midline of the same surface; and point C, in the middle of the lateral surface of the cupula. Depression at points A and B was toward the canal, whereas depression at point C was toward the centre of the cupula. The amount of depression was controlled by a micromanipulator. At point A, the minimum depression facilitating the posterior canal action potential was 1 micron; at point B, a greater amount of depression was needed to produce the action potential. Even a large amount of depression at point C resulted in only a small action potential, possibly because the direction of the sensory cell polarity is along the long axis of the canal.

  4. Quality improvement of photopolimerizable-cement root canal obturation

    Science.gov (United States)

    Lupato Conrado, Luis A.; Frois, Iris M.; Amaro Zangaro, Renato; Munin, Egberto; Kuranaga, Carlos; Dias da Silva, Marcos; do Carmo de Andrade Nono, Maria; Cerquiera Rezende, Mirabel

    2003-06-01

    The sealing cements commonly used for endodontic applications are of the type cured through chemical reactions. During the polymerization process, mechanical contractions are not uncommon, leading to a non-perfect sealing. Photopolymerizable cements usually presents superior performance as compared to those chemically activated. However, difficulties in carrying the light to difficult-to-reach regions like the dental apex preclude those material of being accepted in the dental office routine. This work reports on a novel technique which allow the light curing of photopolymerizable cements in endodontic applications. A special light guide had been developed to allow the curing light to reach and polymerize the sealing cement in the apex region. The technique was tested by using single-root human teeth with normal canal morphology. The Ultradent EndoREZ root canal sealer and a resin-based photopolymerizable filler specially developed for the current application had been used. The cone-shaped light guide was introduced into treated canals filled with the photopolymerizable material, up to the apical region. Light from an argon laser was launched onto the light guide for polymerization. All test samples were immersed in methylene-blue solution for microleakage testing. All samples treated with the self-polymerizable material presented dye penetration to some extent. No sample within the group which had the filling material polymerized by using the light guide presented dye penetration through the canal wall.

  5. El Canal del Atazar I

    Directory of Open Access Journals (Sweden)

    López de Berges y de los Santos, Emilio

    1967-03-01

    Full Text Available The Atazar Canal helps to supply Madrid with water, from the rivers Lozoya, Jarama and Sorbe. The section which operates at present starts at the Torrelaguna dam and finishes at the El Goloso reservoir. Later a further section will be added, from the Atazar dam, on the Lozoya river, to link up with the control dam at Torrelaguna. The canal capacity is 16 m3/sec, and it is 43.47 km long. It has a slope of 4/10.000. The cross section is similar to that of the Jarama canal, already built. There are interconnections between this canal and the Canal Alto, which previously supplied the high and medium part of Madrid. To overcome the ground unevenness 5 syphons have been built, the most important of which is the Colmenar Goloso syphon, which is 10.88 km in length. Construction commenced on December 10, 1962, and water reached Madrid on June 15th, 1966. The initial budget for this project was 1,500 million pesetas.El canal del Atazar refuerza considerablemente el abastecimiento de aguas a Madrid, procedentes de los ríos Lozoya, Jarama y, en un próximo futuro, del Sorbe. El tramo, actualmente en funcionamiento, empieza en el salto de Torrelaguna y finaliza en los depósitos de El Goloso. Más adelante se completará su trazado mediante un nuevo tramo que partirá del embalse de Atazar, en el Lozoya, para unirse al actual en el depósito regulador de Torrelaguna. Su capacidad es de 16 m3/s; su longitud, 43,471 km, y su pendiente, 4 diezmilésimas. La sección tipo es análoga a la del canal del Jarama, de construcción anterior. Mediante la oportuna obra de transvase se realizan intercambios entre este Canal y el Canal Alto que abastecía anteriormente la parte media y alta de la capital. Para salvar los desniveles del terreno se han construido 5 sifones, siendo el más importante el de Colmenar-Goloso, con una longitud de 10,8S4 km. El comienzo de las obras tuvo lugar el 10 de diciembre de 1962, y el agua llegó a Madrid el 15 de junio de 1966. Su

  6. Canals - CANALS_HISTORIC_STRUCTURES_IN: Historic Canal Structures in Indiana (Bernardin-Lochmueller & Associates, Point Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Data depicts the locations of historic structures associated with the Wabash-Erie, Central, and Whitewater Canals constructed in Indiana in from 1830-1870. Canal...

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

    NARCIS (Netherlands)

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

    2013-01-01

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

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  9. Fluidmechanics of semicircular canals revisited

    Science.gov (United States)

    Obrist, Dominik

    2008-05-01

    In this work we find the exact solution for the flow field in a semicircular canal which is the main sensor for angular motion in the human body. When the head is rotated the inertia of the fluid in the semicircular canal leads to a deflection of sensory hair cells which are part of a gelatinous structure called cupula. A modal expansion of the governing equation shows that the semicircular organ can be understood as a dynamic system governed by duct modes and a single cupular mode. We use this result to derive an explicit expression for the displacement of the cupula as a function of the angular motion of the head. This result shows in a mathematically and physically clean way that the semicircular canal is a transducer for angular velocity.

  10. Analysis of ground vibrations produced by an 80 in3 water gun in the Chicago Sanitary and Ship Canal, Lemont, Illinois

    Science.gov (United States)

    Koebel, Carolyn Michelle

    Since its completion in 1910, the Chicago Sanitary and Ship Canal (CSSC) has become a pathway for invasive species (and potentially Asian carp) to reach the Great Lakes. Currently, an electric barrier is used to prevent Asian carp migration through the canal, but the need for a secondary method is necessary, especially when the electric barrier undergoes maintenance. The underwater Asian carp "cannon" (water gun) provides such a method. Analysis of the ground movement produced by an 80 in3 water gun in the CSSC was performed in order to establish any potential for damage to the either the canal or structures built along the canal. Ground movement was collected using 3-component geophones on both the land surface and in boreholes. The peak particle velocities (PPVs) were analyzed to determine if damage would be caused to structures located along the canal. Vector sum velocity ground movement along the canal wall was as high as 0.28 in/s (7.11 mm/s), which is much lower than the United States Bureau of Mines (USBM) ground vibration damage threshold of 0.75 in/s (19.1 mm/s), causing no potential for damage to structures along the canal wall. The dominant frequency of ground motion produced by the water gun is primarily above 40 Hz, so the wave energy should attenuate fairly quickly away from the canal wall, with little disturbance to structures further from the wall.

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  12. A COMPARATIVE EVALUATION OF BOND - STRENGTH BETWEEN NORMAL DENTIN AND CARIES AFFECTED DENTIN: AN INVITRO STUDY

    Directory of Open Access Journals (Sweden)

    Arun

    2015-03-01

    Full Text Available INTRODUCTION: The concept of adhesive dentistry has taken leaps forward and has resulted in a concept of more conservation of tooth structure which in turn enhance the life of teeth. The bonding agent forms a hybrid layer with dentin and its other side co - polymerize with the matrix p hase of dental composite, producing strong micro - mechanical bonding. AIMS AND OBJECTIVE: To evaluate the bond strength of adhesive agent to normal dentin and caries affected dentin and also to compare the bond strength between different bonding agents. METHOD: 20 mandibular molar were collected, washed and stored in normal saline. Each tooth was cut longitudinally. Healthy tooth structure of each half of the tooth represents the control group and the carious portion of the same tooth represents as experi mental group. Thus, 80 samples were prepared. The groups were then further subdivided into 4 sub - groups of 4 different bonding agents. The dentin surface of all the sub groups were etched by 37% of phosphoric acid gel for 10 - 15 secs and respective bonding agent were used and cured for 20 secs. Cylindrical composite resin was prepared using a plastic module of internal diameter of 3mm and length 5mm. Statistical analysis was done using mean standard deviation (S.D, student ‘t’ test and level of significance ‘P’. RESULTS: For both the control and experimental group, 3M single bond has showed the strongest bond strength followed by Prime and Bond NT, Excite and PQ1.

  13. Effect of different techniques on removal of smear layer in dental canal%不同方法去除根管壁玷污层效果的实验研究

    Institute of Scientific and Technical Information of China (English)

    刘雁; 马卫东; 高蔚虹

    2011-01-01

    Objective: To evaluate the ability of different techniques on removal of smear layer in dental canal. Methods: Forty extracted single-rooted human teeth were randomly distributed into 4 groups. The teeth were prepared by ProTaper rotary instruments and subjected to different techniques for the removal of smear layer in dental canals. Hydrogen peroxide ( H2O2 ) and normal saline ( NS )were used in group A; 5.25% sodium hypochlorite(NaClO) and ethylenediamine tetraacetis(EDTA) gel in group B; ulrasonics in group C; 5.25% NaC10 and EDTA gel with ultrasonics in group D. Samples were examined under the scanning electron microscope and scored for smear layer removal and the erosion on the surface of the root canal walls. Results: The whole surfaces of root canals in group A were covered by smear layer. The smear layer of root canals in group B, C and D was removed. Statistical analysis showed that the removal effect in group B, C and D was significantly better than that in group A at coronal, middle and apical portions. There were not significant differences among group B, C and D. In group D the surface of root canal at coronal, middle portion was eroded. Conclusion: 5.25% NaClO with EDTA gel, ultrasonics with 5.25% NaClO, EDTA gel and ultrasonic can effectively remove the smear layer in root canal, but the dentin can be eroded by using 5.25% NaClO with EDTA gel and ultrasonics.%目的:评价4种不同方法去除根管壁玷污层的能力.方法:将40颗离体牙随机分为4组进行根管预备,使用不同方法去除玷污层,分别为:A组H2O2和生理盐水,B组EDTA凝胶和5.25%的NaClO,C组超声波,D组超声波联合5.25%NaCIO+EDTA.将处理后的样本纵剖开,扫描电镜观察4组根管壁的界面,比较3个不同部位玷污层的去除情况、根管壁的清洁程度、牙本质小管的开放程度及腐蚀程度.结果:对照组(A组)根管壁被玷污层覆盖,实验组(B、C、D组)根管壁玷污层去

  14. INSTRUMENTATION OF CURVED CANALS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Senthil Kumar

    2013-02-01

    Full Text Available INTRODUCTION: Nature seldom draws a straight line. Nowhere is thi s more apparent than in the anatomy of teeth roots and root canal systems o f human teeth. Even teeth with straight roots can harbor severely curved canals. Canal shapi ng is a critical aspect of endodontic treatment because it influences the outcome of the subsequent phases of canal irrigation and filling and the success of the treatment itself. In fact, curved canals are the most common endodontic complexity 1 . The need for some manner of root canal preparation pri or to root canal filling has long been recognized as an essential step in endodontic t reatment. Concepts concerning the role and purpose of this canal preparation, however, have differ ed remarkably at different times in the development of endodontics and in the hands of diffe rent practitioners 2

  15. The cartilage bone junction and its implications for deep canal hearing instrument fittings

    DEFF Research Database (Denmark)

    Nielsen, Claus; Darkner, Sune

    2011-01-01

    The popularity of hearing instruments deeply placed in the ear canal has been driven by their superior cosmetic characteristics. However, people fitted with these hear- ing instruments often complain about the sound qual- ity of their voice, which is typically described as being hollow, echoing......, or like talking in a barrel. This problem is caused by the occlusion effect. The effect is primarily due to vibrations of the walls in the soft part of the ear canal, which generate a sound pressure that is trapped in the cavity between the tip of the occluding hearing aid and the tympanic membrane....... If the hearing aid is fitted with a seal in the bony portion of the ear canal, preventing vibration in the soft part of the ear canal from reaching the tympanic membrane, then occlusion problems can be solved or at least reduced in most cases. 1–4 Work carried out by Garcia has shown that if the seal...

  16. Tertiary Dentin Formation after Indirect Pulp Capping Using Protein CPNE7.

    Science.gov (United States)

    Choung, H W; Lee, D S; Lee, Ji-Hyun; Shon, W J; Lee, Jong-Ho; Ku, Y; Park, J C

    2016-07-01

    If there is a partial loss of dentin, the exposed dentinal surface should be protected by an indirect pulp capping (IPC) procedure to preserve pulp vitality and prevent symptoms of dentin hypersensitivity. In our previous study, copine7 (CPNE7) induced odontoblast differentiation in vitro and promoted dentin formation in vivo. The aim of this study was to investigate the possibility of IPC therapy using the CPNE7 protein at the exposed dentinal surface and the resulting effects on tertiary dentin formation in a beagle model. CPNE7 promoted mineralization of odontoblasts and had high calcium ion-binding capacity. The in vivo IPC model with canine teeth showed that regeneration of physiologic reactionary dentin with dentinal tubule structures was clearly observed beneath the remaining dentin in the CPNE7 group, whereas irregular features of reparative dentin were generated in the mineral trioxide aggregate (MTA) group. The CPNE7+MTA group also showed typical reactionary dentin without reparative dentin, showing synergistic effects of CPNE7 with MTA. A scanning electron microscopy analysis showed that dentinal tubules beneath the original dentin were occluded by the deposition of peritubular dentin in the CPNE7 and CPNE7+MTA groups, whereas those in the control group were opened. Therefore, CPNE7 may be able to serve as a novel IPC material and improve symptoms of dentin hypersensitivity. PMID:27013639

  17. Thermal effects of different lasers and dentine

    International Nuclear Information System (INIS)

    Introduction: Irradiation of dental tissue with laserlight leads to development of high temperatures and in this way to partly important damage. The purpose of this study was to assess development of temperature in dentin illuminated with different types of lasers. Material and methods: human teeth were cut horizontally into slices of 0.5, 1.0, 1.5 and 2.0 mm thickness. They were irradiated for 25 seconds. Every five seconds temperature was measured with a thermo-measuring instrument placed at the bottom of the platelets. Er:YAG-, Nd:YAG-, Dioden- and CO2-laser were examined. All together 528 platelets were illuminated. Results: temperatures between 19.3 degree C and 51.1 degree C were measured. There was a rise in temperature with increasing power output of laser. With 1.3 degree C the diodenlaser showed the lowest increase in temperature. There was also a rise in temperature when time of irradiation was extended. At 25 seconds temperature increased about 4.5 degree C working with diodenlaser and 14 degree C with CO2-laser. This increment was more evident in thinner platelets, what can be demonstrated most impressive with Er:YAG-laser. At 0.5 mm thickness we found an increase in temperature of 10.8 degree C, at 2.0 mm of 4.7 degree C. Independent of irradiation time all lasers demonstrated a decrease in temperature with growing thickness of dentin. Conclusion: development of temperature in dental tissue irradiated with several types of lasers shows a dependency from the following factors: 1. temperature rises with augmentation of laser output, 2. temperature rises when time of irradiation is extended, 3. temperature falls with growing thickness of platelets. Further the results demonstrate, that carefully treatment of dentin without pulp damage is most likely possible working with Diodenlaser and Er:YAG-laser. (author)

  18. Diagnosis of Dentin Caries – Ultraviolet Fluorescence

    Directory of Open Access Journals (Sweden)

    Uzunov Ts.

    2014-12-01

    Full Text Available The technology advance in recent years determines the need of construction of modern appliances for early diagnosis of dental caries, which are categorized by great precision, non-invasiveness, easy usage and wide availability. Such non-invasive and accurate tool for diagnostics of caries is Caries Detector (LED, Bulgarian product by “Optica Laser”. The detector emits a specific wavelength of near ultraviolet light, which causes fluorescence to porphyrins - metabolic products of the life cycle of caries-inducing bacteria. The purpose of the study is piloting a new diagnostic tool for detection and monitoring of caries excavation based on fluorescence - LED UV caries detector of company “Optica laser”. Subjected to examination by caries indicator dye and UV caries detector were sixty permanent teeth with deep dentine caries. Two methods were used to assess the dentin caries - UV fluorescence detector of “Optica Laser” and staining with caries indicator - dye (Sable ™ Seek®. It was found that among all sixty teeth, the fields, closed by margins of carious process overlap. Fifty-four of tested teeth has shown bigger field of images with staining method and six - smaller in comparison to the fluorescent method. Ultraviolet fLuorescence caries detector of “Optica Laser” company is affordable and easy applicable method for controlled excavation of dentine caries. The detector can be used in daily dental practice equally with other methods. The unit has a number of advantages - non-invasiveness, lack of interaction with tooth structures, speed, reliability, efficiency, predictability and repeatability of results.

  19. Computed tomography of the thoracic canal

    International Nuclear Information System (INIS)

    Under the adequate CT condition, thoracic canal was studied in twelve normal cases, nine cases of cervical myelopathy with developmental cervical canal stenosis and four cases of thoracic myelopathy with ossification of thoracic yellow ligament. The results were as follows. 1) The adequate condition for delineation of thoracic canal seemed to be nearly 400 EMI units in window width and 150 in level. Scanning angle was permitted within about 100. Bony thoracic canal was well scanned at the center of vertebral body. 2) The configulation of the normal thoracic canal was oval at Th1, Th2 levels and round at Th3-Th10 and large oval at Th11, Th12. The sagittal diameter was almost fixed at each level and the transverse diameter was large at upper and lower levels and small at middle levels. 3) Thoracic canal was narrowed in the cases of cervical myelopathy with developmental cervical canal stenosis especially in sagittal diameter, but not narrowed in transverse diameter. Three of four cases who had myelopathy with ossification of thoracic yellow ligament had narrow canals. 4) There was a good relation between sagittal diameter of cervical canal and thoracic canal. 5) There was a good relation between sagittal diameter of thoracic canal measured by conventional radiographs (Hattori's method) and CT scans. The author thinks that Hattori's method is useful to diagnose the thoracic canal stenosis. (author)

  20. Protein-apatite interactions in dentine

    OpenAIRE

    Boonstra, Willem Douwe

    2008-01-01

    In the last few decades in the whole western world a decline of enamel caries has been observed. This decrease is an immediate result of the apllication of fluorides, of improved eating habits and of a growing dental care. All these factors have resulted in a longer maintenance of the natural dentition by a large fraction of the population. In consequence of this, an increase of root caries as a result of gingival recession has come to the forefront. The roots of teeth consisting of dentine w...

  1. 三种器械预备弯曲根管成形效果的比较%Shaping efficacy of three instruments in curved root canal preparation

    Institute of Scientific and Technical Information of China (English)

    庄沛林; 叶剑涛; 黄卓珊; 余艳崧; 伍虹

    2014-01-01

    Objective To evaluate the shaping efficacy of K files , Safesiders files and HERO Shaper files in curved root canal preparation of human teeth in vitro. Methods Sixty mandibular premolars with curved root canal were divided into three groups randomly, and prepared by K files, Safesiders files and HERO Shaper files respectively. Compound meglumine diatrizoate was injected into root canals and X-ray graphs of teeth were taken before and after instrumentation . The amount of dentin removed from inner and outer walls , centering ability and degree of straightening of root canal after preparation were analyzed. Results Safesiders files and HERO Shaper files removed less dentin from inner and outer walls than K files at all measuring points (P 0.05). The use of K files resulted in more straightening of root canal after instrumentation compared to other instruments (P 0.05). Conclusions K files, Safesiders files and HERO Shaper files caused transportation when preparing curved root canals . Safesiders files and HERO Shaper files showed less transportation and better shaping efficacy .%目的:评价K锉、Safesiders锉和HERO Shaper锉预备离体牙弯曲根管的成形效果。方法60颗根管弯曲的离体下颌前磨牙随机分为3组,分别用K锉、Safesiders锉和HERO Shaper锉进行根管预备,根管预备前后分别往根管内注入复方泛影葡胺并拍摄X线片,分析根管预备后根管弯曲内外侧壁牙本质去除量、中心定位能力及根管直化角度。结果在根管弯曲内外侧壁所有观测点,Safesiders锉组和HERO Shaper锉组牙本质去除量均少于K锉组(P均>0.05)。 Safesiders锉组牙本质去除量多于HERO Shaper锉组,但仅在根管弯曲内侧壁3和4 mm观测点处差异有统计学意义(3 mm:t=3.72,P<0.05;4 mm:t=7.62,P<0.05)。在距根尖孔5 mm以下观测点,Safesiders锉组和HERO Shaper锉组中心定位能力优于K锉组(1 mm:F=7.45,P<0.05;2 mm

  2. Resistance of a novel root canal sealer to bacterial ingress in vitro.

    Science.gov (United States)

    Padachey, N; Patel, V; Santerre, P; Cvitkovitch, D; Lawrence, H P; Friedman, S

    2000-11-01

    A dentin-bonding root canal sealer (ZUT) has been developed, consisting of an experimental glass ionomer cement (KT-308) and an antimicrobial silver-containing zeolite (0.2% by weight). This in vitro study evaluated the ability of ZUT used with or without gutta-percha, to resist bacterial ingress of Enterococcus faecalis over a period of 90 days. Canals of 80 single-rooted teeth were prepared with apical patency and filled as follows (n = 10): KT-308 alone; KT-308 with a single gutta-percha cone (SCGP); ZUT alone; ZUT with SCGP; AH26 alone; AH26 with SCGP; positive control-no root canal filling; and negative control-no root canal filling, with the apices of this group sealed with C&B Metabond cement. Teeth were coated with nail polish except for the apical 2 mm, and each tooth was sealed in a 4-ml glass vial, with an 18-gauge needle inserted through the vial cover and bonded into the pulp chamber with C&B Metabond cement. After sterilization with 2.5 Mrad gamma-radiation, Brain Heart Infusion broth with phenol red was injected into each vial. An inoculum of E. faecalis was pipetted through the needle into the pulp chamber every 5 days, and the broth was monitored daily for color change and turbidity. When change occurred, the broth was cultured for growth of E. faecalis. Kaplan-Meier survival analysis and the log-rank test revealed no significant differences among the three sealers used. The presence of gutta-percha, however, significantly improved resistance to bacterial ingress through obturated root canals (X, p < 0.05). Under the conditions of this study, the hypothesized advantage of ZUT (0.2% zeolite) was not demonstrated. PMID:11469295

  3. The Dehiscent Facial Nerve Canal

    Directory of Open Access Journals (Sweden)

    Sertac Yetiser

    2012-01-01

    Full Text Available Accidental injury to the facial nerve where the bony canal defects are present may result with facial nerve dysfunction during otological surgery. Therefore, it is critical to know the incidence and the type of facial nerve dehiscences in the presence of normal development of the facial canal. The aim of this study is to review the site and the type of such bony defects in 144 patients operated for facial paralysis, myringoplasty, stapedotomy, middle ear exploration for sudden hearing loss, and so forth, other than chronic suppurative otitis media with or without cholesteatoma, middle ear tumors, and anomaly. Correlation of intraoperative findings with preoperative computerized tomography was also analyzed in 35 patients. Conclusively, one out of every 10 surgical cases may have dehiscence of the facial canal which has to be always borne in mind during surgical manipulation of the middle ear. Computerized tomography has some limitations to evaluate the dehiscent facial canal due to high false negative and positive rates.

  4. Contemporary root canal filling strategies

    NARCIS (Netherlands)

    A.T. Moinzadeh

    2016-01-01

    Currently, clinicians can choose from a wide range of root canal filling materials and techniques, some of which have been evaluated in this thesis. Methacrylate resin-based sealers suffer from polymerization shrinkage stresses. This limitation may partly be overcome by a two-step cementation proced

  5. Canal Water Scarcity Hits Farmers

    Institute of Scientific and Technical Information of China (English)

    张忠潮

    2007-01-01

    Acute shortage of canal water for irrigation in this district has caused resentment among the farmers.The water is being released in the various channels for just one week in a month,which is not enough to meet the irrigation needs of the farmers who are preparing their fields for paddy

  6. Micromechanical testing of the dentin hybrid zone formed by all-in-one adhesive system in sound human dentin

    Science.gov (United States)

    Koytchev, E.; Datcheva, M.; Iankov, R.

    2015-10-01

    This study explored the spatial variations in mechanical behavior of the dentin hybrid layer formed by a single step (one bottle) dentin adhesive system. Objective. The objectives were to: (1) evaluate the mechanical behavior of the hybrid zone formed by a single sep dentin adhesive system using nanoindentation technique, (2) compare the indentation moduli (EIT) and indentation hardness (HIT) of human dentin and the hybrid zone, and (3) assess the importance of specimen hydration on the nanoindentation response. Methods. Specimens of human dentin, treated with commercial single step resin adhesive and restored with composite material were evaluated using a nanoindenter in a load-displacement control mode. The load and displacement responses were used to perform nanoindentation characterization of dentin and the hybrid layer and estimate EIT and HIT, using Oliver & Pharr approximation method. Results. In hydrated state, EIT for dentin and hybrid layer were 18.214 ± 1.30 GPa and 12.535 ± 0.19 GPa respectively. For HIT, also in hydrated state, the values in dentin and hybrid layer were 0.56 ± 0.06 GPa and 0.36 ± 0.005 GPa respectively. Viscoelastic deformation of the dentin hybrid zone exceeded that occuring in regions of uniform dentin tissue. The load displacement curves of the two zones were also estimated and analyzed. They generally follow the same pattern without any noticeable pop-ins or irregularities. Significance. The microstructure and hydration play critical roles on the mechanical behavior of the hybrid layer and nanoindentation provides a potent measurment tool for identifying the spatial variations.

  7. Effect of relining on fiber post retention to root canal

    Directory of Open Access Journals (Sweden)

    André Luís Faria-e-Silva

    2009-12-01

    Full Text Available One of the clinically relevant problems dentists face when restoring endodontically treated teeth is the mismatch between fiber post and post space diameters, which results in an excessively thick resin cement layer. Fiber post relining appears as a solution for this problem. OBJECTIVES: The aim of this study was to evaluate the effect of fiber post relining with composite resin on push-out bond strength. MATERIAL AND METHODS: Twenty bovine incisors were selected to assess post retention. The crowns were removed below the cementoenamel junction and the root canals were treated endodontically and flared with diamond burs. The roots were allocated into two groups (n=10: G1: fiber posts without relining and G2: fiber posts relined with composite resin. The posts were cemented with a dual-cured resin cement and the specimens were sectioned transversally. Three 1.5-mm thick slabs were obtained per root and identified as cervical, medium and apical thirds. The push-out test was performed at a crosshead speed of 0.5 mm/min until post dislodgement occurred. The failure mode of fractured specimens was analyzed under scanning electron microscopy. Data were analyzed by split-plot ANOVA and post-hoc Tukey's test at a pre-set alpha of 0.05. RESULTS: Relined fiber posts presented higher retention values than non-relined post in all thirds. No statistically significant differences (p>0.05 were found among thirds for relined posts. All failures occurred at the interface between resin cement and root dentin. CONCLUSIONS: Relining with composite resin seems to be an effective method to improve the retention of fiber posts to flared root canals.

  8. Endodontic Treatment of a Mandibular Second Premolar with Type IV Wiene’s Root Canal: A Case Report

    Directory of Open Access Journals (Sweden)

    Noushad Matavan Chalil

    2014-01-01

    Full Text Available This case report describes an endodontic treatment of a mandibular second premolar with type IV root canal. A 26-year-old male patient reported pain in right mandibular second premolar. Clinical examination showed a large carious lesion with pulp exposure. Radiographs showed minimal periapical changes and slight widening of periodontal ligament space. Mandibular second premolars usually have one canal. The mandibular second premolar may present large number of anatomic variations. The clinician should be aware of the configuration of the pulp system. This case presents the diagnosis and clinical management of a mandibular second premolar with two distinct canals in the apical third of root (Type IV Wiene’s canal configuration, drawing particular attention to tactile examination of all the canal walls and obturating it with calamus 3D obturation system.

  9. Mandibular Second Premolar with Four Canals

    Directory of Open Access Journals (Sweden)

    Javad Ghiasi

    2015-09-01

    Full Text Available A mandibular second premolar with four canals is an interesting example of anatomic variations. This report describes a case of a mandibular second premolar with three roots and four canals (one mesiobuccal, two distobuccal and one lingual. The canals were prepared using K-files and irrigated with NaOCl (5.25% and normal saline as the final irrigant. The canals were filled laterally with gutta percha and AH26 sealer (De Trey, Dentsply, Switzerland. This case shows a rare anatomic configuration and points out the importance of looking for additional canals.

  10. The distribution of magnesium in developing rat incisor dentin

    International Nuclear Information System (INIS)

    Previous studies have shown that rat incisor dentin contains a considerable amount of magnesium that is distributed heterogeneously. The cementum-related dentin, especially its incisal portion, is richest in magnesium. It was the purpose of the present study to investigate the changes that occur in the magnesium content during dentin maturation. Cross-sections were prepared from rat incisors at the apical, middle, and incisal levels. By means of an electron microprobe, tracings were made of the Ca-, Mg-, and P- signal frequencies. Comparison of corresponding dentin layers within and between the cross-sections showed that the Mg/P molar ratio was always higher in the cementum-related dentin (CRD) than in the enamel-related dentin (ERD) and increased from the apex toward the incisal edge. Especially in the incisal cross-section, an increase in Mg/P was found from the older (peripheral) toward the younger (central) dentin layers. As the Mg/P ratio varied from 0.07 to 0.33, the Ca/P ratio was found to fluctuate from 1.48 to 1.15. The two ratios appeared to be highly correlated (r = -0.97; p less than 0.001), suggesting that Mg replaces Ca and is bound to phosphate

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

    Directory of Open Access Journals (Sweden)

    Saad Liaqat

    2015-04-01

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

  12. Carbodiimide inactivation of MMPs and effect on dentin bonding.

    Science.gov (United States)

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

    2014-03-01

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

  13. Synthesis and Characterization of New Chlorhexidine-Containing Nanoparticles for Root Canal Disinfection

    Directory of Open Access Journals (Sweden)

    Ridwan Haseeb

    2016-06-01

    Full Text Available Root canal system disinfection is limited due to anatomical complexities. Better delivery systems of antimicrobial agents are needed to ensure efficient bacteria eradication. The purpose of this study was to design chlorhexidine-containing nanoparticles that could steadily release the drug. The drug chlorhexidine was encapsulated in poly(ethylene glycol–block–poly(l-lactide (PEG–b–PLA to synthesize bilayer nanoparticles. The encapsulation efficiency was determined through thermogravimetric analysis (TGA, and particle characterization was performed through microscopy studies of particle morphology and size. Their antimicrobial effect was assessed over the endodontic pathogen Enterococcus faecalis. The nanoparticles ranged in size from 300–500 nm, which is considered small enough for penetration inside small dentin tubules. The nanoparticles were dispersed in a hydrogel matrix carrier system composed of 1% hydroxyethyl cellulose, and this hydrogel system was observed to have enhanced bacterial inhibition over longer periods of time. Chlorhexidine-containing nanoparticles demonstrate potential as a drug carrier for root canal procedures. Their size and rate of release may allow for sustained inhibition of bacteria in the root canal system.

  14. In vitro evaluation of the root canal cleaning ability of plant extracts and their antimicrobial action

    Directory of Open Access Journals (Sweden)

    Edja Maria Melo de Brito Costa

    2012-06-01

    Full Text Available This in vitro study evaluated both the antimicrobial activity and the root canal cleaning ability of plant extracts used in irrigation solutions. The antimicrobial activities of the aroeira-da-praia (Schinus terebintifolius Raddi and the quixabeira (Syderoxylum obtusifolium Roem & Schult hydroalcoholic extracts, of 2.5% sodium hypochlorite (NaOCl and of 0.12% chlorhexidine (positive control against Enterococcus faecalis were tested with the agar well diffusion method. The level of root canal cleanliness was examined by scanning electron microscopy (SEM. Twenty one single-rooted human teeth were divided into three groups according to the irrigation solution applied: 1 50% aroeira-da-praia; 2 50% quixabeira and 3 a combination of 2.5% sodium hypochlorite + 17% EDTA. All solutions tested demonstrated antimicrobial activity against Enterococcus faecalis. The SEM analysis revealed that higher and lower degrees of surface cleaning were observed, in the three groups, respectively for the coronal and apical thirds, in that quixabeira showed the greatest efficiency in removing the smear layer in the apical third. All the agents tested presented antimicrobial activity against E. faecalis. None, however, was able to completely remove the smear layer of the dentinal surface in the different thirds of the root canal. The results suggest that the analyzed plant extracts may represent a new therapeutic option in the list of alternative agents available for endodontic treatment.

  15. In vitro study of the apical microleakage with resilon root canal filling using different final endodontic irrigants

    OpenAIRE

    Lahor Soler, Eduard; Miranda Rius, Jaume; Brunet Llobet, Lluis; Farré Albaladejo, Magí; Pumarola Suñé, José

    2015-01-01

    Background Endodontic microleakage or microfiltration refers to the percolation of fluids and micro-organisms at the interface of the obturation material and the walls of the root canal system. The aim of this in vitro study was to compare apical microfiltration of Resilon root canal filling by employing three different final irrigant solutions. Material and Methods 128 single-rooted teeth were employed. The crowns were sectioned horizontally at the cemento-enamel junction and instrumented wi...

  16. Cell Wall

    OpenAIRE

    Jamet, Elisabeth; Canut, Hervé; Boudart, Georges; Albenne, Cécile; Pont-Lezica, Rafael F

    2008-01-01

    This chapter covers our present knowledge of cell wall proteomics highlighting the distinctive features of cell walls and cell wall proteins in relation to problems encountered for protein extraction, separation and identification. It provides clues to design strategies for efficient cell wall proteomic studies. It gives an overview of the kinds of proteins that have yet been identified: the expected proteins vs the identified proteins. Finally, the new vision of the cell wall proteome, and t...

  17. Light propagation in dentin: influence of microstructure on anisotropy

    International Nuclear Information System (INIS)

    We investigated the dependence of light propagation in human dentin on its microstructure. The main scatterers in dentin are the tubules, the shape of which can be approximated as long cylinders. We calculated the scattering of electromagnetic waves by an infinitely long cylinder and applied the results in a Monte Carlo code that simulates the light propagation in a dentin slab considering multi-scattering. The theory was compared with goniometric measurements. A pronounced anisotropic scattering pattern was found experimentally and theoretically. In addition, intensity peaks were measured which are shown to be caused by light diffraction by the tubules. (note)

  18. Increment thickness versus dentin bond strength of bulk fill flowables

    OpenAIRE

    Flury, Simon; Peutzfeldt, Anne; Lussi, Adrian

    2013-01-01

    Objectives: The aim was to investigate the influence of increment thickness on shear bond strength (SBS) to dentin of a conventional and two bulk fill flowable composites. Methods: A total of 135 specimens of ground human dentin were produced (n=15/group; 3 increment thicknesses; 3 flowable composites) and the dentin surfaces were treated with the adhesive system OptiBond FL (Kerr) according to manufacturer’s instructions. Split Teflon molds (inner diameter: 3.6 mm) of 2 mm, 4 mm, or 6 mm...

  19. Dentin hypersensitivity: etiology, diagnosis and treatment; a literature review.

    Science.gov (United States)

    Davari, Ar; Ataei, E; Assarzadeh, H

    2013-09-01

    The objective of this review is to inform practitioners about dentin hypersensitivity (DH); to provide a brief overview of the diagnosis, etiology and clinical management of dentin hypersensitivity and to discuss technical approaches to relieve sensitivity. This clinical information is described in the context of the underlying biology. The author used PUBMED to find relevant English-language literature published in the period 1999 to 2010. The author used combinations of the search terms "dentin*", "tooth", "teeth", "hypersensit*", "desensitiz*". Abstracts and also full text articles to identify studies describing etiology, prevalence, clinical features, controlled clinical trials of treatments and relevant laboratory research on mechanisms of action were used. PMID:24724135

  20. Dentine hypersensitivity. The effects in vitro of acids and dietary substances on root-planed and burred dentine.

    Science.gov (United States)

    Addy, M; Absi, E G; Adams, D

    1987-05-01

    Evidence indicates that teeth exhibiting cervical dentine hypersensitivity have open dentinal tubules at the dentine surface. The identification of factors which render dentine exposed and tubules open is important both to the prevention and management of dentine hypersensitivity. In this study, recently extracted teeth were root planed or burred to expose the root dentine. Specimens were horizontally sectioned and then using the apical portion as control, the coronal portions placed in a variety of strong and weak acids and dietary fluids. Examination under the scanning electron microscope revealed a smear layer covering completely underlying tubules on the control root planed or burred portions. Test portions exposed to strong and weak acids showed loss of the smear layer and exposure of large numbers of tubules. Formic and tannic acids produced no changes. Some dietary fluids, in particular red and white wine, citrus fruit juices, apple juice and yogurt produced similar etching effects to the acids. The low pH carbonated drink, coca-cola, and a blackcurrent cordial produced no effects. The results of this study in vitro cannot necessarily be extrapolated to the clinical situation, but suggest that certain dietary factors could play a rôle in the aetiology of dentine hypersensitivity. Dietary advice to patients may prove important in the management of this often recurrent condition. PMID:3301914

  1. Alterations of the Danger Zone after Preparation of Curved Root Canals Using WaveOne with Reverse Rotation or Reciprocation Movements

    Science.gov (United States)

    Shantiaee, Yazdan; Dianat, Omid; Paymanpour, Payam; Nahvi, Golnaz; Ketabi, Mohammad Ali; Kolahi Ahari, Golbarg

    2015-01-01

    Introduction: The aim of this study was to compare the changes that occur in the danger zone (DZ) after preparation of curved mesiobuccal (MB) canals of mandibular first molars with WaveOne instruments in two different movements [reciprocation (RCP) and counter-clockwise rotation (CCWR)] by means of cone-beam computed tomography (CBCT). Methods and Materials: MB canals of 30 mandibular molars were randomly divided into 2 groups (n=15); WaveOne/RCP and WaveOne/CCWR. Pre- and post-instrumentation CBCT images were assessed for changes in the dentin thickness in DZ (2 and 4 mm below the highest point of the root furcation) in both groups. Data was analyzed using the repeated measures ANOVA test. Results: There was no statistically significant difference between two experimental groups in terms of remaining dentin thickness at 2 and 4 mm levels below the highest point of the furcation (P>0.05). Conclusion: The efficacy of WaveOne instrument on changes of the dentin thickness in the DZ was not affected by different file movements. PMID:26213536

  2. Shear bond strength of two resin cements to human root dentin using three dentin bonding agents.

    Science.gov (United States)

    Gogos, C; Stavrianos, C; Kolokouris, I; Economides, N; Papadoyannis, I

    2007-01-01

    This study compared the bond strength of two resin cements to human root dentin when used with three bonding agents. The materials used were Rely X ARC and Perma Cem, two one-bottle bonding agents (Single Bond, Bond-1) and one self-etching bonding agent (Clearfil SE Bond). The dentin was obtained from single rooted human teeth, and the specimens were treated with either 15% EDTA or 37% phosphoric acid to remove the smear layer, except in groups where the self-etching bonding agent was used. The resin cements were placed on dentin surfaces with the use of bonding agents. Shear bond strength (SBS) was tested using a single plane shear test assembly. The dentin specimens were divided into 10 groups. Eight groups were pre-treated with EDTA or phosphoric acid to remove the smear layer, followed by a bonding agent (Bond-1 or Single Bond) and resin cement (Rely X or Perma Cem). In the two remaining groups, the smear layer was left intact, and the two resins cements were used in combination with the self-etching bonding agent (Clearfil SE Bond). No statistically significant differences were observed among the eight groups treated with one-bottle bonding agents. The mean bond strengths of the two groups treated with the self-etching bonding agent did not differ significantly from each other but were both significantly greater than the bond strengths of all the other groups. The results of this study also showed that EDTA can be used as an alternative to phosphoric acid in bonding procedures for resin cements. However, the bond strengths of resin cements, in combination with a self-etching bonding agent, were significantly greater than those of the same cements when used with one-bottle bonding agents.

  3. Microbiome of Deep Dentinal Caries Lesions in Teeth with Symptomatic Irreversible Pulpitis

    Science.gov (United States)

    Rôças, Isabela N.; Rachid, Caio T. C. C.; Lima, Kenio C.; Assunção, Isauremi V.; Gomes, Patrícia N.; Siqueira, José F.

    2016-01-01

    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. PMID:27135405

  4. 锥束CT在变异根管诊断治疗中的作用%Application of CBCT in the diagnosis and treatment of teeth with canal varieties

    Institute of Scientific and Technical Information of China (English)

    刘荣森; 高飞; 石校伟; 李颖超

    2011-01-01

    Objective: To evaluate the value of CBCT(Cone Beam Computed Tomography) in diagnosis and treatment of teeth with canal varieties through analysis of clinical root canal treatment cases. Methods:PROMAX3D CBCT imaging system was used to examine 300 root canal treatment cases for demonstrating radiographic features of the root canal system compared with their conventional radiography.Results: CBCT images can distinctly demonstrate the morphology and orientation of the root canal system in three dimensions providing definite information for the diagnosis of incisor double canals, molar canal varieties and C-shaped root canals. Conclusions: CBCT examination can provide clear radiographic images of root canal system varieties prior to and during the endodontic procedures, which would be helpful to prevent missed canals, conserve healthy dentin and guarantee the success of root canal treatment.%目的:通过研究根管治疗病例的锥形束CT(CBCT)影像,探讨这一技术在变异根管诊断治疗中的作用.方法:使用ProMAX3D CBCT设备,分析比较300例根管治疗病例CBCT和常规X光片根管腔的影象特点.结果:CBCT能够三维显示根管的形态和分布,发现切牙双根管、磨牙根管数目异常、C形根管等根管变异.结论:CBCT可在根管治疗术前术中对根管变异作出明确的诊断,对防止根管遗漏、保存牙本质和保障根管治疗成功有一定的临床指导意义.

  5. Retention of Root Canal Posts

    DEFF Research Database (Denmark)

    Sahafi, A; Benetti, Ana Raquel; Flury, S;

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc...... received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement......, pretreatment with tribochemical silicate coating significantly increased retention of the posts. Increased cement film thickness resulted in decreased retention of untreated posts and of pretreated posts luted with zinc phosphate cement. Increased cement film thickness had no influence on retention...

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

    Directory of Open Access Journals (Sweden)

    Robert Dalby

    2012-01-01

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

  7. Role of Dentin Compositional Changes and Structural Loss on Fracture Predilection in Endodontically Treated Teeth

    Science.gov (United States)

    Ossareh, Arezou

    The aim of this study was to examine the role of chemical compositional changes and iatrogenic dentin structural loss on the mechanical response of teeth to force and resistance to fracture. The experiments were divided into three phases. In phase 1, experimental studies were performed to evaluate the effect of chemicals used during treatment on ultrastructure, composition and resistance to fracture of dentin. In phase 2, experimental studies were used to evaluate the influence of dentin removal and remaining dentin volume on the resistance to fracture and microcrack formation in root dentin. In phase 3 finite element analysis was carried out to examine the influence of dentin loss on the stress distribution in root dentin. The combination of experimental and numerical analysis highlighted the role of remaining dentin volume and moment of inertia on root dentin biomechanics.

  8. Role of the confinement of a root canal on jet impingement during endodontic irrigation

    Science.gov (United States)

    Verhaagen, B.; Boutsioukis, C.; Heijnen, G. L.; van der Sluis, L. W. M.; Versluis, M.

    2012-12-01

    During a root canal treatment the root canal is irrigated with an antimicrobial fluid, commonly performed with a needle and a syringe. Irrigation of a root canal with two different types of needles can be modeled as an impinging axisymmetric or non-axisymmetric jet. These jets are investigated experimentally with high-speed Particle Imaging Velocimetry, inside and outside the confinement (concave surface) of a root canal, and compared to theoretical predictions for these jets. The efficacy of irrigation fluid refreshment with respect to the typical reaction time of the antimicrobial fluid with a biofilm is characterized with a non-dimensional Damköhler number. The pressure that these jets induce on a wall or at the apex of the root canal is also measured. The axisymmetric jet is found to be stable and its velocity agrees with the theoretical prediction for this type of jet, however, a confinement causes instabilities to the jet. The confinement of the root canal has a pronounced influence on the flow, for both the axisymmetric and non-axisymmetric jet, by reducing the velocities by one order of magnitude and increasing the pressure at the apex. The non-axisymmetric jet inside the confinement shows a cascade of eddies with decreasing velocities, which at the apex does not provide adequate irrigation fluid refreshment.

  9. Role of Alcohol on the Fracture Resistance of Dentin

    Energy Technology Data Exchange (ETDEWEB)

    Nalla, Ravi K.; Kinney, John H.; Tomsia, Antoni P.; Ritchie,Robert O.

    2006-05-01

    Healthy dentin, the mineralized tissue that makes up the bulk of the tooth, is naturally hydrated in vivo; however, it is known that various chemical reagents including acetone and ethanol can induce dehydration and thereby affect its properties. Here, we seek to investigate this in light of the effect alcohol can have on the mechanical properties of dentin, specifically by measuring the stiffness, strength and toughness of dentin in simulated body fluid and scotch whisky. Results indicate that chemical dehydration induced by the whisky has a significant beneficial effect on the elastic modulus, strength and fracture toughness of dentin. Although this makes teeth more resistant to fracture, the change in properties is fully reversible upon rehydration. This effect is considered to be associated with increased cross-linking of the collagen molecules from intermolecular hydrogen-bonding where water is replaced with weaker hydrogen-bond forming solvents such as alcohol.

  10. 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 pulps is concerned. PMID:27307049

  11. Application of 17% EDTA Enhances Diffusion of (45)Ca-labeled OH(-) and Ca(2+) in Primary Tooth Root Canal.

    Science.gov (United States)

    Ximenes, Marcos; Cavalcanti Taguchi, Carolina Mayumi; Triches, Thaisa Cezaria; Sartori, Neimar; Pereira Dias, Luis Alberto; de Araujo, Elaine Bortoleti; Cardoso, Mariane

    2016-01-01

    Proper cleaning of the root canal is key to the success of endodontic treatment as it allows more effective diffusion of medication throughout the dentinal tubules. The aim of this in vitro study was to investigate the efficacy of 17% ethylenediaminetetraacetic acid (EDTA) in enhancing diffusion of hydroxyl (OH(-)) and calcium ions (Ca(2+)) throughout the root canal in primary teeth. The canals of 25 primary tooth roots were cleaned with endodontic files and 1% sodium hypochlorite. Three groups (G) were then established: GI, in which final irrigation was performed with 1% sodium hypochlorite; GII, in which 17% EDTA was used; and GIII, in which no irrigation was performed. The roots canals in GI and GII were filled with a calcium hydroxide-based paste labeled with the radioisotope calcium-45. Diffusion of OH(-) was detected with pH strips and Ca(2+) analyzed by measuring radioactivity in counts per min. Group II differed statistically from the other groups in diffusion of OH(-) at 24 hr (p<0.05), but no significant difference among groups was found at the day 7 evaluation; GII also differed statistically from the other groups in diffusion of Ca(2+) at 24 hr (p<0.05). These results suggest that application of 17% EDTA in primary tooth enhances diffusion of OH(-) and Ca(2+). PMID:26961333

  12. Antimicrobial efficacy of different root canal sealers by using real-time polymerase chain reaction: An ex vivo study

    Directory of Open Access Journals (Sweden)

    R Gnana Seelan

    2015-01-01

    Full Text Available Background: Root canal sealers help to minimize leakage, provides antimicrobial activity to reduce the possibility of residual bacteria, and to resolve periapical lesion. Aim: To compare five different root canal sealers against Enterococcus faecalis in an infected root canal model by using real-time polymerase chain reaction (RT-PCR. Settings and Design: Sixty human mandibular premolars were sectioned to standardize a uniform length of 14 mm. Fifty microliters of the inoculum containing E. faecalis were transferred into each microcentrifuge tube (n = 60. The samples were divided into six groups Tubli-Seal, Apexit Plus, Fillapex, AH Plus, RoekoSeal, and Positive control, respectively. Materials and Methods: Five groups after the incubation with the microorganism E. faecalis were coated with different root canal sealers and obturated using F3 ProTaper Gutta-percha point. The dentinal shavings were collected and analyzed for RT-PCR. Statistical Analysis: The mean difference between six groups was calculated using analysis of variance and post-hoc test. Results: The highest antibacterial activity was achieved with Tubli-Seal (1938.13 DNA in pictogram [pg] and least by RoekoSeal (3034.54 DNA in pg. Conclusion: The maximum antimicrobial activity was achieved AH Plus and Tubli-Seal. RT-PCR can be used as a valuable and accurate tool for testing antimicrobial activity.

  13. Push-out bond strength of fiber posts to root dentin using glass ionomer and resin modified glass ionomer cements

    Directory of Open Access Journals (Sweden)

    Jefferson Ricardo PEREIRA

    2014-10-01

    Full Text Available OBJECTIVE: The purpose of this study was to assess the push-out bond strength of glass fiber posts to root dentin after cementation with glass ionomer (GICs and resinmodified glass ionomer cements (RMGICs. MATERIAL AND METHODS: Fifty human maxillary canines were transversally sectioned at 15 mm from the apex. Canals were prepared with a step back technique until the application of a #55 K-file and filled. Post spaces were prepared and specimens were divided into five groups according to the cement used for post cementation: Luting & Lining Cement; Fuji II LC Improved; RelyX Luting; Ketac Cem; and Ionoseal. After cementation of the glass fiber posts, all roots were stored at 100% humidity until testing. For push-out test, 1-mm thick slices were produced. The push-out test was performed in a universal testing machine at a crosshead speed of 0.5 mm/minute and the values (MPa were analyzed by Kolmogorov-Smirnov and Levene's tests and by two-way ANOVA and Tukey's post hoc test at a significance level of 5%. RESULTS: Fiber posts cemented using Luting & Lining Cement, Fuji II LC Improved, and Ketac Cem presented the highest bond strength to root dentin, followed by RelyX Luting. Ionoseal presented the lowest bond strength values (P>0.05. The post level did not influence the bond strength of fiber posts to root dentin (P=0.148. The major cause of failure was cohesive at the cement for all GICs and RMGICs. CONCLUSIONS: Except for Ionoseal, all cements provided satisfactory bond strength values.

  14. Analytical transmission electron microscopy of mineralised dentin

    International Nuclear Information System (INIS)

    The use of FIB milling as a TEM sample preparation tool for mineralised dentin was investigated in order to gain a better understating of the nanostructure of bone-like specimens. A clear advantage of FIB milling over ultramicrotomy, the traditional preparation route in biological systems, is that dehydration, embedding and section flotation can be obviated, thus reducing both physical and chemical damage to the specimen prior to examination. The characteristic periodic contrast of collagen fibrils is clearly visible in FIB sections without the need for any chemical staining. The nature of the organic/inorganic interface was studied using EELS and EFTEM mapping in a state-of-the-art monochromated FEG(S)TEM.

  15. Strain Distribution in Root Surface Dentin of Maxillary Central Incisors during Lateral Compaction.

    Directory of Open Access Journals (Sweden)

    Raphael Pilo

    Full Text Available To precisely quantify the circumferential strains created along the radicular dentin of maxillary incisors during a simulated clinical procedure of lateral compaction.Six miniature strain gauges were bonded on the roots of fourteen recently extracted maxillary central incisors that were subjected to root canal instrumentation. The strain gauges were bonded at three levels (apical, middle, and coronal and four aspects (buccal, lingual, mesial, and distal of the roots. Each tooth was embedded in a PVC cylinder containing polyvinyl-siloxane impression material. Root filling was then performed by simulating the clinical procedure of lateral compaction using nickel-titanium finger spreaders. The force applied to the spreader and the strains developing in the surface root dentin were continuously recorded at a frequency of 10 Hz.The highest strains that developed during lateral compaction were in the mesial and distal aspects at the apical level of the root. The magnitudes of the maximal mesial/distal strains at the apical as well as the mid-root levels were approximately 2.5-3 times higher than those at the buccal/lingual aspects (p = 0.041. The strains decreased significantly (p<0.04 from the apical through the mid-root levels to the coronal level, yielding gradients of 2.5- and 6-fold, respectively. The mesial and distal strains were consistently tensile and did not differ significantly; however, the buccal strains were generally 35-65% higher than the lingual strains (p = 0.078. Lateral compaction resulted in the gradual build-up of residual strains, resulting in generation of a 'stair-step' curve. These strains declined gradually and almost completely disappeared after 1000 sec.With proper mounting of several miniature strain gauges at various levels and aspects of the root, significant circumferential strains can be monitored under clinically relevant compaction forces. The residual strains at the end of lateral compaction are not stored in the

  16. Dentine hypersensitivity: analysis of self-care products

    OpenAIRE

    Cassiano Kuchenbecker Rösing; Tiago Fiorini; Diego Nique Liberman; Juliano Cavagni

    2009-01-01

    Dentine hypersensitivity is a condition that is often present in individuals, leading them to seek dental treatment. It has been described as an acute, provoked pain that is not attributable to other dental problems. Its actual prevalence is unknown, but it is interpreted as very unpleasant by individuals. Several therapeutic alternatives are available to manage dentine hypersensitivity, involving both in-office treatment and home-use products. The aim of this literature review was to evaluat...

  17. Methods for biomimetic remineralization of human dentine: A systematic review

    OpenAIRE

    Chris Ying Cao; May Lei Mei; Quan-Li Li; Edward Chin Man Lo; Chun Hung Chu

    2015-01-01

    This study aimed to review the laboratory methods on biomimetic remineralization of demineralized human dentine. A systematic search of the publications in the PubMed, TRIP, and Web of Science databases was performed. Titles and abstracts of initially identified publications were screened. Clinical trials, reviews, non-English articles, resin-dentine interface studies, hybrid layer studies, hybrid scaffolds studies, and irrelevant studies were excluded. The remaining papers were retrieved wi...

  18. Determination of some variables of human dentin for dosimetric purposes

    International Nuclear Information System (INIS)

    The initial objective of this work is to determine the atomic composition of human dentin, using various techniques of measurements such as X-Ray fluorescence, atomic absorption, spectrophotometry, volumetric analysis, chemistry, colorimetry and thermogravimetry. With the values of the effective atomic number Z bar dependent of the quality of the ionizing radiation, one can find the kind of material that can be used for a phantom equivalent to dentin. (author)

  19. Effect of Vitality on Translucent Dentine – A Study

    OpenAIRE

    M, Selvamani; G S, Madhushankari; S Basandi, Praveen; Donoghue, Mandana; Nayak, Vaidehi; Diwakar, Gajendra

    2013-01-01

    Background: Sclerosis of dentinal tubules may be a response to pathological or physiological insult in the crown & root. The mechanism by which apical translucency is produced is still uncertain. The increase in size of the apical zone of sclerotic dentin in human teeth has been used often in forensic science as a method of age estimation. However, only few studies have been done to compare percentage of translucency between vital and non-vital teeth. Conflicting concepts exist regarding the...

  20. Nanostructural changes in dentine caused by endodontic irrigants

    OpenAIRE

    Barón, Marta; Llena Puy, María Carmen; Forner Navarro, Leopoldo; Palomares Fort, María; González García, Cristina; Salmerón Sánchez, Manuel

    2013-01-01

    Objective: To study nanostructural dentinal changes produced by endodontic irrigants. Study Design: Experimental study. Nanoindentations were performed on peritubular (PD) and intertubular dentine (ID) with an atomic force microscopy. Stiffness and adhesion force were determined before and after application of 5.25% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA). Normalized differences before and after treatment for stiffness and adhesion forces were calculated. A ...

  1. Amalgam stained dentin: a proper substrate for bonding resin composite?

    OpenAIRE

    Feilzer, A.J.; Özcan, M.; Kleverlaan, C. J.; Scholtanus, J.D. (Hans)

    2016-01-01

    Nowadays the use of dental amalgam is mostly abandoned and substituted by tooth colored resin composites that can be bonded to teeth tissues by adhesive techniques. The aim of this thesis was to find out whether dark stained dentin, as often observed after removal of amalgam restorations and attributed to penetration of corrosion products, is an adequate substrate for bonding resin composite restorations. Previous studies revealed tin and zinc as main metals from amalgam in stained dentin and...

  2. Factors associated with dentine hypersensitivity severity in Colombian dental patients.

    OpenAIRE

    Luis López; Paola Espana; Ruth Bastidas; Jeovanni Fuelagan; Ana Cristina Mafla

    2016-01-01

    Introduction: The aim of this study was to determine the prevalence of dentine hypersensitivity (DH) and examine associated etiological factors related to the severity of DH in dental clinic patients treated at the School of Dentistry at Universidad Cooperativa de Colombia, Pasto, Colombia. Materials and Methods: A cross-sectional study was designed in which three hundred and thirty three patients aged 15 to 44 years old were assessed for the presence and severity of DH. The dentine hypersen...

  3. Shaping ability of ProFile.04 Taper Series 29 rotary nickel-titanium instruments in simulated root canals. Part 2.

    Science.gov (United States)

    Thompson, S A; Dummer, P M

    1997-01-01

    The aim of this study was to determine the shaping ability of ProFile.04 Taper Series 29 rotary nickel-titanium instruments in simulated canals. A total of 40 simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared by ProFile instruments using a step-down approach. Part 2 of this two-part report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and the overall postoperative shape. No zips, perforations or danger zones were created although 24 specimens (60%) had ledges on the outer wall of the canal. The incidence of ledges differed significantly (P canal shapes. At specific points along the canal length there were highly significant differences (P canal width and in the amount of material removed from the inner and outer aspects of the curve between the various canal shapes. Overall, 40 degrees canals were wider than 20 degrees canals and canals with curves which began 8 mm from the orifice were wider than 12 mm canals. The direction of canal transportation at the end-point of preparation was balanced between inner and outer in the 8 mm canals, but more often towards the outer in the 12 mm canals. At the apex of the curve, transportation was invariably towards the outer aspect of the curvature. At the beginning of the curve, transportation was more balanced between inner and outer. Mean absolute transportation, ignoring direction, was generally greater in 40 degrees canals and in those with the curve beginning 8 mm from the orifice. Of particular importance was the finding that excessive resin was removed from the outer aspect of the canal at the apex of the curve which was often associated with irregular widened areas or ledges. This is in contrast to the pattern of tissue removal found with stainless steel hand instruments where more resin is removed from the inner aspect of the canal at the apex, to create a danger zone

  4. The effect of electropolishing on torque and force during simulated root canal preparation with ProTaper shaping files.

    Science.gov (United States)

    Boessler, Claudia; Paque, Frank; Peters, Ove A

    2009-01-01

    Surface modifications of nickel-titanium instruments such as electropolishing may reduce fracture incidence but could potentially alter the instruments' mechanical properties. We studied the impact of two surface types, machined and electropolished, of ProTaper shaping files on torque and force during simulated root canal preparation. Pilot holes of 0.5-mm diameter were drilled perpendicularly through 3-mm thick human dentin discs and served as standardized simulated root canals (SSRCs). A total of 300 SSRCs were prepared with ProTaper Sx, S1, and S2 instruments using an automated testing platform. Maximum torque (in Ncm) and maximum force values (in N) were measured. In three experimental groups (Sx, S1, and S2) preparation of SSRCs was performed using electropolished versus machined instruments in the same dentin disc. For all three tested instruments, peak torque was higher for electropolished files; apically exerted forces were similar, except for Sx, in which machined instruments developed higher forces. We conclude that surface treatment by electropolishing alters the cutting ability of nickel-titanium rotary instruments. PMID:19084135

  5. Effects of cleaning agents on bond strength to dentin Efeitos de agentes de limpeza na resistência adesiva à dentina

    OpenAIRE

    Celso Rosin; Victor Elias Arana-Chavez; Narciso Garone Netto; Maria Aparecida Alves de Cerqueira Luz

    2005-01-01

    The cleaning of cavity walls aims to improve adhesive restorative procedures and longevity of restorations. This study has compared the effect of three cleaning agents - sodium bicarbonate jet (Profi II, Dabi Atlante, São Paulo, Brazil); pumice paste plus a biologic detergent (Tergestesim, Probem, São Paulo, Brazil); air water spray - on the bond strength between dentin and two different adhesive systems: Clearfil SE Bond (Kuraray, Kioto, Japan) and Scotchbond Multi-Purpose Plus (3M-ESPE, São...

  6. Analytical method to estimate resin cement diffusion into dentin

    Science.gov (United States)

    de Oliveira Ferraz, Larissa Cristina; Ubaldini, Adriana Lemos Mori; de Oliveira, Bruna Medeiros Bertol; Neto, Antonio Medina; Sato, Fracielle; Baesso, Mauro Luciano; Pascotto, Renata Corrêa

    2016-05-01

    This study analyzed the diffusion of two resin luting agents (resin cements) into dentin, with the aim of presenting an analytical method for estimating the thickness of the diffusion zone. Class V cavities were prepared in the buccal and lingual surfaces of molars (n=9). Indirect composite inlays were luted into the cavities with either a self-adhesive or a self-etch resin cement. The teeth were sectioned bucco-lingually and the cement-dentin interface was analyzed by using micro-Raman spectroscopy (MRS) and scanning electron microscopy. Evolution of peak intensities of the Raman bands, collected from the functional groups corresponding to the resin monomer (C–O–C, 1113 cm-1) present in the cements, and the mineral content (P–O, 961 cm-1) in dentin were sigmoid shaped functions. A Boltzmann function (BF) was then fitted to the peaks encountered at 1113 cm-1 to estimate the resin cement diffusion into dentin. The BF identified a resin cement-dentin diffusion zone of 1.8±0.4 μm for the self-adhesive cement and 2.5±0.3 μm for the self-etch cement. This analysis allowed the authors to estimate the diffusion of the resin cements into the dentin. Fitting the MRS data to the BF contributed to and is relevant for future studies of the adhesive interface.

  7. Nested Canalizing Functions and Their Networks

    CERN Document Server

    Kadelka, Claus; Adeyeye, John O; Laubenbacher, Reinhard

    2014-01-01

    The concept of a nested canalizing Boolean function has been studied over the last decade in the context of understanding the regulatory logic of molecular interaction networks, such as gene regulatory networks. Such networks are predominantly governed by nested canalizing functions. Derrida values are frequently used to analyze the robustness of a Boolean network to perturbations. This paper introduces closed formulas for the calculation of Derrida values of networks governed by Boolean nested canalizing functions, which previously required extensive simulations. Recently, the concept of nested canalizing functions has been generalized to include multistate functions, and a recursive formula has been derived for their number, as a function of the number of variables. This paper contains a detailed analysis of the class of nested canalizing functions over an arbitrary finite field. In addition, the concept of nested canalization is further generalized and closed formulas for the number of such generalized fun...

  8. Stability of guest molecules in urea canal complexes by canal polymerization

    International Nuclear Information System (INIS)

    It was found that various organic materials are attracted into urea canal by hexanediol diacrylate (HDDA) and long chain compounds. This means that materials which does not form complex by itself are induced in canal by HDDA and long chain compounds. To include with stability perfumes, insecticides, attractants and repellents in urea canal, leaf alcohol was used as a model compound for guest molecules in the canal. The leaf alcohol from the canal released gradually over many days and the release was inhibited for 15 days by long chain compounds and for 30 days by polymerized HDDA after irradiation. After releasing, the leaf alcohol in the canal remained 25 % stable for long chain compounds and 40 % for polymerized HDDA. The dose required for stabilization of leaf alcohol in the urea canal by canal polymerization of HDDA was 30 kGy. (author)

  9. Stability of guest molecules in urea canal complexes by canal polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Yoshii, Fumio; Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1995-03-01

    It was found that various organic materials are attracted into urea canal by hexanediol diacrylate (HDDA) and long chain compounds. This means that materials which does not form complex by itself are induced in canal by HDDA and long chain compounds. To include with stability perfumes, insecticides, attractants and repellents in urea canal, leaf alcohol was used as a model compound for guest molecules in the canal. The leaf alcohol from the canal released gradually over many days and the release was inhibited for 15 days by long chain compounds and for 30 days by polymerized HDDA after irradiation. After releasing, the leaf alcohol in the canal remained 25 % stable for long chain compounds and 40 % for polymerized HDDA. The dose required for stabilization of leaf alcohol in the urea canal by canal polymerization of HDDA was 30 kGy. (author).

  10. Canals, DMADCanals-Irrigation canals in Millard Co., Published in 2007, Millard County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2007. It is described as 'DMADCanals-Irrigation canals in Millard Co.'. Data by this...

  11. Effect of multi-step and single- step dentin bonding agents on the bond strength of composite to dentin

    Directory of Open Access Journals (Sweden)

    Maleknejad F

    2002-07-01

    Full Text Available Composite resin restorative materials, that nowadays are used as tooth-colour materials, have both benefits and weaknesses. One of these weaknesses is the contraction resulted from resin polymerization which influences on the composite dentin bond strength and it has been tried to be eliminated by different bonding systems. The aim of this in-vitro study was to compare the dentin bond strength of two dentine adhesive systems: multi-step Scoth Bond Multipurpose (SBMP and single- step Excite, by two composites of Ideal Makoo and Tetric. One hundred sixty (160 sound human molars were selected. At first they were debrided and mounted with acrylic resin in molds. The enamel of the buccal surface was eliminated by diamond burs. To provide a flat dentin surface, it was removed about lmm. Then, based on the type of dentin adhesive, they were divided into two groups of 30 teeth and were applied on the exposed dentine surface according to the manufacturer's instructions. Then, each group was divided into two subgroups of 15, based on the type of composite resin. Cylinders of the desired composite resin, attached to the dentin surface, were used for 80 seconds. The samples were stored in 100% humidity (37°c for 24 hours. The bond strengths was measured by a cross head blade with the speed of 2mm/min. Variance analysis and Duncan test, with 95% confidence level, showed that statistically, two factors of adhesive and composite, interact on each other, in bond strength. There was no significant difference in bond strength, between two composites with similar adhesives, however, comparing two different adhesives with the same composite, showed that the bond strength of Tetric with Excite (28.39 was more than that of SBMP (17.98 Mpa. Finally, it was recognized that among four experimental groups, there was only a significant difference in bond strengths, between Tetric-Excite with Tetric- SBMP. This study shows that dentin bond strength is influenced by

  12. Complicated canal morphology of mandibular first premolar

    Science.gov (United States)

    Pallavi, Vyapaka; Kumar, Janga Ravi; Mandava, Ramesh Babu; Rao, Subramanian Hari

    2015-01-01

    The aim of this article was to report an unusual anatomic variation of mandibular first premolar, with one root and three distinct canals, which leave pulp chamber and merge short of apex to exit as two separate apical foramina. The incidence of three canals existing as two apical foramina has only been documented in the literature by a few case reports. To achieve successful endodontic treatment, the clinician has to identify the different canal configurations and treat them properly. PMID:26538977

  13. The number and probability of canalizing functions

    OpenAIRE

    Just, Winfried; Shmulevich, Ilya; Konvalina, John

    2003-01-01

    Canalizing functions have important applications in physics and biology. For example, they represent a mechanism capable of stabilizing chaotic behavior in Boolean network models of discrete dynamical systems. When comparing the class of canalizing functions to other classes of functions with respect to their evolutionary plausibility as emergent control rules in genetic regulatory systems, it is informative to know the number of canalizing functions with a given number of input variables. Th...

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

    Directory of Open Access Journals (Sweden)

    Rebeca Di Nicoló

    2007-10-01

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

  15. 不同方法预备根管对根管治疗后牙齿冠渗漏的影响%Effect of different techniques in root canal preparation on coronal microleakage of endodontically treated teeth

    Institute of Scientific and Technical Information of China (English)

    刘雁; 马卫东; 高蔚虹

    2012-01-01

    目的 采用3种不同方法预备根管,评价其对根管治疗后牙齿冠渗漏的影响.方法 48颗单根管离体牙随机分为4组,使用不同的根管预备方法去除根管壁的玷污层.A组为对照组,采用生理盐水和过氧化氢溶液冲洗根管;B组采用乙二胺四乙酸(EDTA)凝胶和5.25%次氯酸钠溶液冲洗;C组采用Odontoson-M型超声波治疗仪荡洗;D组采用脉冲Nd:YAG激光照射.每组取2颗牙,于扫描电子显微镜(SEM)下观察冠部玷污层的去除情况:其余10颗牙采用ObturaⅡ高温注射式热牙胶垂直加压法充填根管,氧化锌丁香油黏固剂封闭根管口,浸于质量浓度20 g·L-1亚甲基蓝溶液中染色7d,脱水脱钙制作透明牙标本,体视显微镜下测量染料渗入的深度.结果 SEM观察:A组整个根管内壁被覆玷污层及大量碎屑,牙本质小管被堵塞;B组与C组根管内壁清洁,玷污层消失,牙本质小管开放;D组根管内壁牙本质小管封闭或半封闭,玷污层熔融消失.A、B、C、D组染料渗入深度分别为(2.15±0.38)、(1.75±0.28)、(2.04±0.40)、(1.73±0.36) mm.A组的渗入深度明显高于B、D组,其差异有统计学意义(P<0.05).结论 使用不同的方法预备根管去除玷污层,可以减少根管治疗后牙齿的冠渗漏.%Objective To compare the effect of three techniques in root canal preparation on coronal microlea-kage of endodontically treated teeth. Methods Forty-eight human single-rooted teeth were divided into 4 groups randomly and subjected to different techniques on removal of smear layer. Group A, the control group, irrigation with hydrogen peroxide (H2O2) and normal saline (NS); group B, smear cleared with 5.25% sodium hypochlorite (NaCIO) and ethylenediamine tetraacetis (EDTA) gel; group C, irrigation with Odontoson-M ultrasonics; group D, smear layer removed with Nd: YAG laser irradiation. Two specimens of every group were split longitudinally into equal segments and canal walls at coronal

  16. Cervical shaping in curved root canals: comparison of the efficiency of two endodontic instruments Desgaste cervical em canais curvos: comparação entre a eficiência de dois instrumentos endodônticos

    Directory of Open Access Journals (Sweden)

    Sandra Soares Kühne Busquim

    2002-12-01

    Full Text Available The aim of this study was to determine the removal of dentin produced by number 25 (0.08 Flare files (Quantec Flare Series, Analytic Endodontics, Glendora, California, USA and number 1 e 2 Gates-Glidden burs (Dentsply - Maillefer, Ballaigues, Switzerland, in the mesio-buccal and mesio-lingual root canals, respectively, of extracted human permanent inferior molars, by means of measuring the width of dentinal walls prior and after instrumentation. The obtained values were compared. Due to the multiple analyses of data, a nonparametric test was used, and the Kruskal-Wallis test was chosen. There was no significant difference between the instruments as to the removal of dentin in the 1st and 2nd millimeters. However, when comparing the performances of the instruments in the 3rd millimeter, Flare files promoted a greater removal than Gates-Glidden drills (p > 0.05. The analysis revealed no significant differences as to mesial wear, which demonstrates the similar behavior of both instruments. Gates-Glidden drills produced an expressive mesial detour in the 2nd and 3rd millimeters, which was detected trough a statistically significant difference in the wear of this region (p > 0.05. There was no statistically significant difference between mesial and lateral wear when Flare instruments were employed.O propósito do presente trabalho foi determinar o desgaste promovido em dentina pelas limas Flare número 25 (0,08 (Quantec Flare Series, Analytic Endodontics, Glendora, Califórnia, EUA e pelas brocas Gates-Glidden números 1 e 2 (Dentsply-Maillefer, Ballaigues, Suíça, nos canais mesiovestibular e mesiolingual, respectivamente, de molares inferiores permanentes humanos extraídos, através da medição, em milímetros, da espessura das paredes dentinárias antes e posteriormente à instrumentação. Os valores dos desgastes obtidos foram comparados entre si. A análise dos resultados, baseada no teste estatístico não-paramétrico de Kruskal

  17. 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

  18. Narrow, duplicated internal auditory canal

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, T. [Servico de Neurorradiologia, Hospital Garcia de Orta, Avenida Torrado da Silva, 2801-951, Almada (Portugal); Shayestehfar, B. [Department of Radiology, UCLA Oliveview School of Medicine, Los Angeles, California (United States); Lufkin, R. [Department of Radiology, UCLA School of Medicine, Los Angeles, California (United States)

    2003-05-01

    A narrow internal auditory canal (IAC) constitutes a relative contraindication to cochlear implantation because it is associated with aplasia or hypoplasia of the vestibulocochlear nerve or its cochlear branch. We report an unusual case of a narrow, duplicated IAC, divided by a bony septum into a superior relatively large portion and an inferior stenotic portion, in which we could identify only the facial nerve. This case adds support to the association between a narrow IAC and aplasia or hypoplasia of the vestibulocochlear nerve. The normal facial nerve argues against the hypothesis that the narrow IAC is the result of a primary bony defect which inhibits the growth of the vestibulocochlear nerve. (orig.)

  19. Root Canal Treatment of a Maxillary Second Premolar with Two Palatal Root Canals: A Case Report.

    Science.gov (United States)

    Golmohammadi, Maryam; Jafarzadeh, Hamid

    2016-01-01

    Accurate diagnosis of the root canal morphology and anatomy is essential for thorough shaping and cleaning of the entire root canal system and consequent successful treatment. This report describes a case of maxillary second premolar with two roots and three root canals (two mesial and distal palatal canals). The case report underlines the importance of complete knowledge about root canal morphology and possible variations, coupled with clinical and radiographic examination in order to increase the ability of clinicians to treat difficult cases. PMID:27471538

  20. A forensic aspect of age characteristics of dentine using transversal microradiography: a case report

    OpenAIRE

    Vasiliadis, Leonidas; Stavrianos, Christos; Kafas, Panagiotis

    2009-01-01

    Background Translucency of dentine is the result of occlusion of the corresponding dentinal tubules by a mineral substance which has a refractive index similar to that of the rest of the dentine. Case presentation This case report describes the microradiographic features of an upper cadaveric canine. Transverse microradiograph is one of the methods assessing apical dentine translucency for various dental and medical reasons. Conclusion Estimation of age using teeth structures may be of primar...

  1. The effect of fluoride toothpaste on root dentine demineralization progression: a pilot study

    OpenAIRE

    Juliana Nunes Botelho; Altair Antoninha Del Bel Cury; Wander José da Silva; Livia Maria Andaló Tenuta; Jaime Aparecido Cury

    2014-01-01

    The anticaries effect of fluoride (F) toothpaste containing 1100 µg F/g in reducing enamel demineralization is well established, but its effect on dentine has not been extensively studied. Furthermore, it has been shown that toothpaste containing a high F concentration is necessary to remineralize root dentine lesions, suggesting that a 1100 µg F/g concentration might not be high enough to reduce root dentine demineralization, particularly when dentine is subjected to a high cariogenic challe...

  2. Prevalence of dentine hypersensitivity: A cross-sectional study in rural Punjabi Indians

    OpenAIRE

    Dhaliwal, Jagjit Singh; Palwankar, Pooja; Khinda, Paramjit K.; Sodhi, Sachinjeet K.

    2012-01-01

    Aims and Objectives: To study the prevalence of dentine hypersensitivity and related risk factors in rural population of Punjab, India. Materials and Methods: A total of 650 subjects reporting dentine sensitivity were included in the study comprising of 270 males and 380 females. All the subjects completed an interview and the subjects reporting dentine hypersensitivity were examined further using air syringe to put a blast of air to confirm the diagnosis of dentine hypersensitivity. Periodon...

  3. [Upper lateral incisor with 2 canals].

    Science.gov (United States)

    Fabra Campos, H

    1991-01-01

    Clinical case summary of the patient with an upper lateral incisor with two root canals. The suspicion that there might be an anatomic anomaly in the root that includes a complex root canal system was made when an advanced radicular groove was detected in the lingual surface or an excessively enlarged cingulum. PMID:1659854

  4. 33 CFR 117.438 - Company Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Company Canal. 117.438 Section 117.438 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.438 Company Canal. (a) The draw of...

  5. [Upper lateral incisor with 2 canals].

    Science.gov (United States)

    Fabra Campos, H

    1991-01-01

    Clinical case summary of the patient with an upper lateral incisor with two root canals. The suspicion that there might be an anatomic anomaly in the root that includes a complex root canal system was made when an advanced radicular groove was detected in the lingual surface or an excessively enlarged cingulum.

  6. Blending Canal Surfaces Based on PH Curves

    Institute of Scientific and Technical Information of China (English)

    Chen-Dong Xu; Fa-Lai Chen

    2005-01-01

    In this paper, a new method for blending two canal surfaces is proposed. The blending surface is itself a generalized canal surface, the spine curve of which is a PH (Pythagorean-Hodograph) curve. The blending surface possesses an attractive property - its representation is rational. The method is extensible to blend general surfaces as long as the blending boundaries are well-defined.

  7. Effect of Dentin Bonding Agent on the Prevention of Tooth Discoloration Produced by Mineral Trioxide Aggregate

    Directory of Open Access Journals (Sweden)

    Majid Akbari

    2012-01-01

    Full Text Available Objective. Determination of the effect of dentin bonding agent (DBA on the prevention of tooth discoloration produced by mineral trioxide aggregate (MTA. Methods. 50 teeth were endodontically treated and after removal of 3 mm of obturating materials were divided into five groups. In white MTA (WMTA and grey MTA (GMTA groups, these materials were placed in root canal below the orifice. In DBA + WMTA and DBA + GMTA groups, DBAs were applied in the access cavity. Then, 3 mm of WMTA and GMTA was placed. The last 10 teeth served as control. All of teeth were restored and color measurement was recorded for each specimen at this time and 6 months later. Results. The mean tooth discoloration in WMTA and GMTA groups was significantly more than DBA + WMTA and DBA + GMTA groups, respectively. There was no significant difference between DBA + WMTA and DBA + GMTA groups and control group. Conclusion. Application of DBA before MTA may prevent tooth discoloration.

  8. Chlorhexidine as a root canal irrigant: Antimicrobial and scanning electron microscopic evaluation

    Directory of Open Access Journals (Sweden)

    Živković Slavoljub

    2010-01-01

    Full Text Available Introduction. Selection of irrigant is very important for longterm success of root canal therapy. Objective. This study was undertaken to evaluate the antimicrobial effects of 2% chlorhexidine digluconate solution (CHX against five selected microorganisms and to evaluate its efficacy in root canal cleaning. Methods. In this study, by agar diffusion test, were evaluated antimicrobial effects of three root canal irrigants: 5.25% NaOCl, 2.5% NaOCl and 2% CHX. The microorganisms tested in this study were Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, Escherichia coli and Candida albicans. A scanning electron microscope was used to evaluate root canal cleaning ability of 5.25% NaOCl, 2.5% NaOCl, 2% CHX and 15% EDTA. Twelve extracted single-root human teeth were divided into four groups depending on the irrigant used during instrumentation. Mechanical preparation was performed with Step back technique and K files. Data were analyzed statistically by Student’s t-test. Results 5.25% NaOCl was the most effective against all tested microorganisms. 2.5% NaOCl and 2% CHX showed antimicrobial effects against all tested microorganisms but zones of inhibition were smaller. The best results in root canal walls cleaning were obtained in the group where the irrigant was 15% EDTA (score 2.33. In 5.25% NaOCl, 2.5% NaOCl and 2% CHX groups, there was more smear layer (score 4 and 5. Conclusion. 2% chlorhexidine digluconate showed strong antimicrobial effect on the tested microorganisms, but was not effective in cleaning root canal walls.

  9. Type III apical transportation of root canal

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    Shiv P Mantri

    2012-01-01

    Full Text Available Procedural accidents leading to complications such as canal transportation have been ascribed to inapt cleaning and shaping concepts. Canal transportation is an undesirable deviation from the natural canal path. Herewith a case of apical transportation of root canal resulting in endodontic retreatment failure and its management is presented. A healthy 21-year-old young male presented discomfort and swelling associated with painful endodontically retreated maxillary incisor. Radiograph revealed periradicular radiolucency involving underfilled 11 and overfilled 12. Insufficiently obturated 11 exhibited apical transportation of canal. This type III transportation was treated by periradicular surgery and repair using white mineral trioxide aggregate (MTA. Comfortable asymptomatic patient presented uneventful healing at third and fourth month recall visits. A decrease in the size of radiolucency in radiograph supported the clinical finding. In the present case, MTA is useful in repairing the transportation defect. The result of these procedures is predictable and successful.

  10. Machining human dentin by abrasive water jet drilling.

    Science.gov (United States)

    Kohorst, Philipp; Tegtmeyer, Sven; Biskup, Christian; Bach, Friedrich-Wilhelm; Stiesch, Meike

    2014-01-01

    The aim of this experimental in-vitro study was to investigate the machining of human dentin using an abrasive water jet and to evaluate the influence of different abrasives and water pressures on the removal rate. Seventy-two human teeth had been collected after extraction and randomly divided into six homogeneous groups (n=12). The teeth were processed in the area of root dentin with an industrial water jet device. Different abrasives (saccharose, sorbitol, xylitol) and water pressures (15 or 25 MPa) were used in each group. Dimensions of dentin removal were analysed using a stripe projection microscope and both drilling depth as well as volume of abrasion were recorded. Morphological analyses of the dentin cavities were performed using scanning electron microscopy (SEM). Both drilling depth and volume of abrasion were significantly influenced by the abrasive and the water pressure. Depending on these parameters, the drilling depth averaged between 142 and 378 μm; the volume of abrasion averaged between 0.07 and 0.15 mm3. Microscopic images revealed that all cavities are spherical and with clearly defined margins. Slight differences between the abrasives were found with respect to the microroughness of the surface of the cavities. The results indicate that abrasive water jet machining is a promising technique for processing human dentin. PMID:24642975

  11. 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.

  12. Machining human dentin by abrasive water jet drilling.

    Science.gov (United States)

    Kohorst, Philipp; Tegtmeyer, Sven; Biskup, Christian; Bach, Friedrich-Wilhelm; Stiesch, Meike

    2014-01-01

    The aim of this experimental in-vitro study was to investigate the machining of human dentin using an abrasive water jet and to evaluate the influence of different abrasives and water pressures on the removal rate. Seventy-two human teeth had been collected after extraction and randomly divided into six homogeneous groups (n=12). The teeth were processed in the area of root dentin with an industrial water jet device. Different abrasives (saccharose, sorbitol, xylitol) and water pressures (15 or 25 MPa) were used in each group. Dimensions of dentin removal were analysed using a stripe projection microscope and both drilling depth as well as volume of abrasion were recorded. Morphological analyses of the dentin cavities were performed using scanning electron microscopy (SEM). Both drilling depth and volume of abrasion were significantly influenced by the abrasive and the water pressure. Depending on these parameters, the drilling depth averaged between 142 and 378 μm; the volume of abrasion averaged between 0.07 and 0.15 mm3. Microscopic images revealed that all cavities are spherical and with clearly defined margins. Slight differences between the abrasives were found with respect to the microroughness of the surface of the cavities. The results indicate that abrasive water jet machining is a promising technique for processing human dentin.

  13. The Difference of Structural State and Deformation Behavior between Teenage and Mature Human Dentin.

    Science.gov (United States)

    Panfilov, Peter; Zaytsev, Dmitry; Antonova, Olga V; Alpatova, Victoria; Kiselnikova, Larissa P

    2016-01-01

    Objective. The cause of considerable elasticity and plasticity of human dentin is discussed in the relationship with its microstructure. Methods. Structural state of teenage and mature human dentin is examined by using XRD and TEM techniques, and their deformation behavior under compression is studied as well. Result. XRD study has shown that crystallographic type of calcium hydroxyapatite in human dentin (calcium hydrogen phosphate hydroxide Ca9HPO4(PO4)5OH; Space Group P63/m (176); a = 9,441 A; c = 6,881 A; c/a = 0,729; Crystallite (Scherrer) 200 A) is the same for these age groups. In both cases, dentin matrix is X-ray amorphous. According to TEM examination, there are amorphous and ultrafine grain phases in teenage and mature dentin. Mature dentin is stronger on about 20% than teenage dentin, while teenage dentin is more elastic on about 20% but is less plastic on about 15% than mature dentin. Conclusion. The amorphous phase is dominant in teenage dentin, whereas the ultrafine grain phase becomes dominant in mature dentin. Mechanical properties of human dentin under compression depend on its structural state, too. PMID:26989416

  14. Evaluation of accessory furcation canals of permanent mandibular molars using radiography and clearing = Avaliação do canal cavo-interradicular em molares inferiores permanentes através de Rx e diafanização

    Directory of Open Access Journals (Sweden)

    Harb, Leandro José Corrêa

    2010-01-01

    Full Text Available Objetivo: Avaliar a presença do canal cavo-interradicular em molares inferiores permanentes através de radiografias e diafanização. Metodologia: A amostra foi constituída por 344 molares inferiores re-hidratados, preparados e armazenados individualmente em recipientes de vidro. A presença do canal cavo-interradicular foi investigada por um único operador treinado usando lupa (4x para as radiografias e microscópio óptico odontológico (30x para as amostras diafanizadas. Microscopia eletrônica de varredura (MEV foi usada para verificar diferenças morfológicas do assoalho pulpar. Resultados: A análise radiográfica mostrou que 9% das amostras tinham uma zona levemente radiolúcida, 2% mostravam uma imagem sugestiva, e 89% das amostras não tinham nenhuma evidência. Pela diafanização, o canal não foi encontrado nas amostras avaliadas. Pela MEV, as amostras recém extraídas mostraram com canalículos dentinários uniformes; as demais apresentaram pequenos sítios com canalículos uniformes. Conclusão: O exame radiográfico não foi o melhor método de diagnóstico; a diafanização é um excelente método avaliativo, pois permite a visualização tridimensional da anatomia interna dental em pesquisas in vitro

  15. MRI Findings in Spinal Canal Stenosis

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    Maryam Barzin

    2010-05-01

    Full Text Available Spinal canal stenosis results from progressive narrowing of the central spinal canal and the lateral recesses. Primary (congenital lumbar spinal stenosis is associated with achondroplastic dwarfism. The spinal canal may become narrowed by bulging or protrusion of the intervertebral disc annulus, herniation of the nucleus pulposus posteriorly, thickening of the posterior longitudinal ligament, hypertrophy of the facet joints, hypertrophy of the ligamentum flavum, epidural fat deposition, spondylosis of the intervertebral disc margins and uncovertebral joint hypertrophy in the neck. The central canal and the neurorecess may be compromised by tumor infiltration, such as metastatic disease, or by infectious spondylitis."nAP diameter of the normal adult cervical canal has a mean value of 17-18 mm at vertebral levels C3-5. The lower cervical canal measures 12-14 mm. Cervical stenosis is associated with an AP diameter of less than 10 mm. The thoracic spinal canal varies from 12 to 14 mm in diameter in the adult. The diameter of the normal lumbar spinal canal varies from 15 to 27 mm. Lumbar stenosis results from a spinal canal diameter of less than 12 mm in some patients; a diameter of 10 mm is definitely stenotic."nSpinal MRI is the most suitable technique for the diagnosis of spinal stenosis. The examination should be performed using thin sections (3 mm and high resolution, including the axial and sagittal planes using T1-weighted, proton-density, and T2-weighted techniques. The bony and osteophytic components are seen best using a T2-weighted gradient-echo technique."nOn MRI, findings of spinal stenosis have a variable presentation depending on the specific disease. The goal of spinal imaging is to localize the site and level of disease and to help differentiate between conditions in which patients require surgery or conservative treatment."nIn this presentation, different kinds of spinal canal stenosis and their MRI findings would be discussed.

  16. Influence of antimicrobial solutions in the decontamination and adhesion of glass-fiber posts to root canals

    Science.gov (United States)

    HARAGUSHIKU, Gisele Aihara; BACK, Eduardo Donato Eing Engelke; TOMAZINHO, Paulo Henrique; BARATTO, Flares; FURUSE, Adilson Yoshio

    2015-01-01

    Objective This study evaluated the effect of root canal disinfectants on the elimination of bacteria from the root canals, as well as their effect on glass-fiber posts bond strength. Material and Methods Fifty-three endodontically treated root canals had post spaces of 11 mm in length prepared and contaminated with E. faecalis. For CFU/ml analysis, eight teeth were contaminated for 1 h or 30 days (n=4). Teeth were decontaminated with 5% NaOCl, 2% CHX, or distilled water. As control, no decontamination was conducted. After decontamination, sterile paper points were used to collect samples, and CFU/ml were counted. For push-out, three groups were evaluated (n=15): irrigation with 2.5% NaOCl, 2% CHX, or sterile distilled water. A bonding agent was applied to root canal dentin, and a glass-fiber post was cemented with a dual-cured cement. After 24 h, 1-mm-thick slices of the middle portion of root canals were obtained and submitted to the push-out evaluation. Three specimens of each group were evaluated in scanning electron microscopy (SEM). Data were analyzed with one-way ANOVA and Dunnett’s T3 test (α=0.05). Results The number of CFU/ml increased from 1 h to 30 days of contamination in control and sterile distilled water groups. Decontamination with NaOCl was effective only when teeth were contaminated for 1 h. CHX was effective at both contamination times. NaOCl did not influence the bond strength (p>0.05). Higher values were observed with CHX (ppost bonding. PMID:26398518

  17. Wonderful Walls

    Science.gov (United States)

    Greenman, Jim

    2006-01-01

    In this article, the author emphasizes the importance of "working" walls in children's programs. Children's programs need "working" walls (and ceilings and floors) which can be put to use for communication, display, storage, and activity space. The furnishings also work, or don't work, for the program in another sense: in aggregate, they serve as…

  18. Ambiguous walls

    DEFF Research Database (Denmark)

    Mody, Astrid

    2012-01-01

    of “ambiguous walls” as a more “critical” approach to design [1]. The concept of ambiguous walls refers to the diffuse status a lumious and possibly responsive wall will have. Instead of confining it can open up. Instead of having a static appearance, it becomes a context over time. Instead of being hard...

  19. Developmentof the safety monitoring system of hydraulic structuresof the Moscow canal

    Directory of Open Access Journals (Sweden)

    Levachev Stanislav Nikolaevich

    2015-05-01

    Full Text Available The basis of the enterprise “Moscow Canal” in its present state is the canal Moscow - Volga constructed in 1937. Today “Moscow Canal” is the biggest water transport and water industry complex. It has 10 filiations and solves a substantial complex of tasks. One of the most important part of hydraulic structures operation is their observation or monitoring of their safety, which gives us timely and adequate picture of their work and helps to forecast and prevent emergency situations.The article is devoted to the development of the monitoring system of the waterworks of the Moscow canal beginning with the moment of its construction to the present time, the observation analysis of the condition of the walls of canal locks chambers, lock no. 2 where destructive processes in the operation of the walls were first discovered and different methods of liquidation of their development were made. The main problems in the field of monitoring of hydrotechnical structures of the Moscow canal are identified basing on the analysis of the observations.

  20. 牙本质唾液酸焦磷酸蛋白和牙本质%Dentin sialophosphoprotein and dentin

    Institute of Scientific and Technical Information of China (English)

    胡鑫瑜; 王浩洋

    2010-01-01

    在牙本质,两个编码Ⅰ型胶原蛋白基因的突变会导致成骨发育不全.除了胶原蛋白,在牙本质还有一定数量的非胶原蛋白.在牙本质非胶原蛋白编码的基因中,只有牙本质唾液酸焦磷酸蛋白(dentin sialophosphoprotein,DSPP)的突变引起遗传性牙齿畸形.DSPP的突变会引起牙本质发育不全(dentinogenesis imperfecta,DGI)Ⅰ型、Ⅱ型和牙本质发育异常(dentin dysplasia,DD)Ⅱ型.DSPP由成牙质细胞表达并分泌.分泌之后,DSPP由多个细胞外蛋白酶酶切成小片.DSPP被蛋白酶酶切为三个主要部分:牙本质涎蛋白(dentin sialoprotein,DSP),牙本质糖蛋白(dentin glycoprotein,DGP)和牙本质磷蛋白(dentin phosphoprotein,DPP).本文就这三种蛋白的最新进展进行回顾.

  1. Dentin hassasiyeti ve tedavi yöntemleri

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    Atilla Berberoglu

    2012-01-01

    Full Text Available

    Dentin hypersensitivity (DH is a relatively common problem experienced in clinical dental practice. This condition has been defined as a short, sharp pain arising from exposed dentin in response to stimuli typically thermal, evaporative, tactile, osmotic or chemical and which cannot be described to any other form of dental defect or pathology. DH may ocur as a result of exposed dentinal tubules through either loss of enamel or gingival recession. Management strategies, which take into account aetiological factors and patient’s oral hygeine behaviour, should be considered before the home or in office treatment protocols. Treatment plan should include reduce fluid flow in the tubules by means of occlude exposed tubules and block the nerve response in the pulp with many desensitizing chemical agents or phyisical agents which also include lasers. The purpose of this review is to summarize the definition, epidemiology, mechanism, aetiology, diagnosis and treatment protocols of dentin hypersensitivity.

    Key words: Dentine hypersensitivity, aetiology, diagnosis, laser, desensitizing agents.

     

    ÖZET

    Günümüzde giderek artan bir sorun olarak karşımıza çıkan dentin hassasiyeti (DH herhangi bir dental defekt veya patoloji ile açıklanamayan, kimyasal, termal, temas, ozmotik veya buharlaştırıcı uyarana karşı ortama açılmış dentin yüzeylerinden yayılan, kısa süreli keskin bir ağrı olarak tanımlanmaktadır. Sert doku kaybı veya dişeti çekilmesiyle dentin yüzeyinin açığa ve dentin kanallarının oral kaviteye doğru açılmasıyla DH oluşabilir. Evde veya klinikte uygulanacak tedavinin belirlenmesinden önce tedavi planı etiyolojik faktörler ve hastan

  2. Dentin Hypersensitivity: Etiology, Diagnosis and Treatment; A Literature Review

    Science.gov (United States)

    Davari, AR; Ataei, E; Assarzadeh, H

    2013-01-01

    The objective of this review is to inform practitioners about dentin hypersensitivity (DH); to provide a brief overview of the diagnosis, etiology and clinical management of dentin hypersensitivity and to discuss technical approaches to relieve sensitivity. This clinical information is described in the context of the underlying biology. The author used PUBMED to find relevant English-language literature published in the period 1999 to 2010. The author used combinations of the search terms “dentin*”, “tooth”, “teeth”, “hypersensit*”, “desensitiz*”. Abstracts and also full text articles to identify studies describing etiology, prevalence, clinical features, controlled clinical trials of treatments and relevant laboratory research on mechanisms of action were used. PMID:24724135

  3. Bond strength of adhesives to dentin contaminated with smoker's saliva.

    Science.gov (United States)

    Pinzon, Lilliam M; Oguri, Makoto; O'Keefe, Kathy; Dusevish, Vladimir; Spencer, Paulette; Powers, John M; Marshall, Grayson W

    2010-02-01

    The purpose of this study was to determine the effects of contamination with smoker's and non-smoker's saliva on the bond strength of resin composite to superficial dentin using different adhesive systems. The interfacial structure between the resin and dentin was evaluated for each treatment using environmental scanning electron microscopy (ESEM). Freshly extracted human molars were ground with 600-grit SiC paper to expose the superficial dentin. Adhesives [One-Up-Bond-F-Plus (OUFP) and Adper-Prompt-L-Pop (APLP)] and resin composite (TPHSpectrum) were bonded to the dentin (n = 8/group, 180 total specimens) under five surface conditions: control (adhesive applied following manufacturers' instructions); saliva, then 5-s air dry, then adhesive; adhesive, saliva, 5-s air dry; adhesive, saliva, 5-s water rinse, 5-s air dry (ASW group); and adhesive, saliva, 5-s water rinse, 5-s air dry, reapply adhesive (ASWA group). After storage in water at 37 degrees C for 24 h, the specimens were debonded under tension at a speed of 0.5 mm/min. ESEM photomicrographs of the dentin/adhesive interfaces were taken. Mean bond strength ranged from 8.1 to 24.1 MPa. Fisher's protected least significant difference (P = 0.05) intervals for critical adhesive, saliva, and surface condition differences were 1.3, 1.3, and 2.1 MPa, respectively. There were no significant differences in bond strength to dentin between contamination by smoker's and nonsmoker's saliva, but bond strengths were significantly different between adhesive systems, with OUFP twice as strong as APLP under almost all conditions. After adhesive application and contamination with either smoker's or nonsmoker's saliva followed by washing and reapplication of the adhesive (ASWA group), the bond strength of both adhesive systems was the same as that of the control group.

  4. Factors associated with dentine hypersensitivity severity in Colombian dental patients.

    Directory of Open Access Journals (Sweden)

    Luis López

    2016-03-01

    Full Text Available Introduction: The aim of this study was to determine the prevalence of dentine hypersensitivity (DH and examine associated etiological factors related to the severity of DH in dental clinic patients treated at the School of Dentistry at Universidad Cooperativa de Colombia, Pasto, Colombia. Materials and Methods: A cross-sectional study was designed in which three hundred and thirty three patients aged 15 to 44 years old were assessed for the presence and severity of DH. The dentine hypersensitivity diagnosis was based on self-reported sensitivity and a clinical examination. The questionnaire included socio-demographic information, data about oral health habits and acidic dietary intake. A descriptive analysis was performed and the association between DH severity and risk factors was determined using an ordinal logistic regression model. Results: Dentine hypersensitivity was detected in 88 out of 333 (26.4% subjects (95% CI: 21.83-31.56. The pH of natural juices (OR=6.013; 95% CI: 0.995–36.319, p=0.051 and pH of alcohol beverages (OR= 7.800; 95% CI: 2.282–26.658, p=0.001 were significantly associated with the severity of dentine hypersensitivity. Conclusions: The results indicated that the prevalence of dentine hypersensitivity in these patients was consistent with previous reports. Furthermore, the severity of DH was influenced by acidic diet. These results suggest that dental counseling should be provided to all patients as well as to those with dentine hypersensitivity to prevent the occurrence of this oral health problem as well as the severity of symptoms.

  5. Abnormal dentin structure in two novel gene mutations [COL1A1, Arg134Cys] and [ADAMTS2, Trp795-to-ter] causing rare type I collagen disorders.

    Science.gov (United States)

    De Coster, P J; Cornelissen, M; De Paepe, A; Martens, L C; Vral, A

    2007-02-01

    Histological and ultrastructural observations of dentin of two patients affected with rare types of type I collagen disorders are presented. In the first case, a homozygous nonsense mutation in ADAMTS2 (substitution of a codon for tryptophan by a stopcodon) causes type VIIC Ehlers-Danlos syndrome (EDS) with multiple tooth agenesis and focal dysplastic dentin defects. In the second case, a missense mutation in COL1A1 (substitution of arginine by cysteine) results in a type I EDS phenotype with clinically normal-appearing dentition. Tooth samples are investigated by using light microscopy (LM), transmission electron microscopy (TEM) and immunostaining for types I and III collagen, and tenascin. These are compared with samples from patients with types III and IV osteogenesis imperfecta (OI) in association with dentinogenesis imperfecta (DI), showing a consistently abnormal appearance of the dentin in all specimens, with variations being primarily those of degree of change. Similarities in histological changes include the alternating presence of normal and severe pathological areas in primary and secondary dentin, the latter being characterized by large canal-like structures in atubular areas. Ultrastructural evidence of pathological dentinogenesis include abnormal distribution, size and organization of collagen fibers, which may also be found in clinically unaffected teeth. The histological and ultrastructural changes seen can be explained on the basis of odontoblast dysfunction which may be secondary to the collagen defect, interfering with different levels of odontoblast cell function and intercellular communication. These observations on (ultra)structural dentin defects associated with the two novel gene mutations are the first ever reported. PMID:17118335

  6. Panama Canal Watershed Experiment- Agua Salud Project

    Science.gov (United States)

    Stallard, Robert F.; Ogden, Fred L.; Elsenbeer, Helmut; Hall, Jefferson S.

    2010-01-01

    The Agua Salud Project utilizes the Panama Canal’s (Canal) central role in world commerce to focus global attention on the ecosystem services provided by tropical forests. The Canal was one of the great engineering projects in the world. Completed in 1914, after almost a decade of concerted effort, its 80 km length greatly shortened the voyage between the Atlantic and Pacific Oceans. An entire class of ships, the Panamax, has been constructed to maximize the amount of cargo that can be carried in a Canal passage. In today’s parlance, the Canal is a “green” operation, powered largely by water (Table 1). The locks, three pairs on each end with a net lift of 27 meters, are gravity fed. For each ton of cargo that is transferred from ocean to ocean, about 13 tons of water (m3) are used. Lake Gatún forms much of the waterway in the Canal transect. Hydroelectricity is generated at the Gatún dam, whenever there is surplus water, and at Madden Dam (completed in 1936) when water is transferred from Lake Alhajuela to Lake Gatún. The Canal watershed is the source of drinking water for Panama City and Colon City, at either end of the Canal, and numerous towns in between.

  7. Evaluation of caries-affected dentin with optical coherence tomography

    OpenAIRE

    Cynthia Soares de Azevedo; Luciana Cardoso Espejo Trung; Maria Regina Lorenzetti Simionato; Anderson Zanardi de Freitas; Adriana Bona Matos

    2011-01-01

    The purpose of this study was to evaluate the degree of demineralization of artificially induced caries-affected human dentin by an in vitro microbiological method. The occlusal surfaces of 6 human molar teeth were abraded until a flat surface was obtained, and the enamel was removed to expose the occlusal dentin surface. These teeth were sectioned in 12 halves in the vestibular-lingual direction and divided into 3 groups according to the period length of the microbiological essay (n = 4): G1...

  8. COHESIVE STRENGTH OF DENTIN RESISTÊNCIA COESIVA DA DENTINA

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    Flávio Fernando DEMARCO

    1997-07-01

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

  9. Influence of handpiece maintenance sprays on resin bonding to dentin

    Directory of Open Access Journals (Sweden)

    Toyotarou Sugawara

    2010-03-01

    Full Text Available Toyotarou Sugawara1, Atsushi Kameyama2, Akiko Haruyama3, Takumi Oishi4, Nobuyuki Kukidome2, Yasuaki Takase2, Masatake Tsunoda21Undergraduate Student, Tokyo Dental College, Chiba, Japan; 2Division of General Dentistry, Tokyo Dental College Chiba Hospital, Chiba, Japan; 3Department of Dental Materials Science, Tokyo Dental College, Chiba, Japan; 4Department of Dentistry and Oral Surgery, Keio University School of Medicine, Tokyo, JapanObjective: To investigate the influence of maintenance spray on resin bonding to dentin.Materials and methods: The crown of extracted, caries-free human molars was transversally sectioned with a model trimmer to prepare the dentin surfaces from mid-coronal sound dentin, and then uniformly abraded with #600 silicon carbide paper. The dentin surfaces were randomly divided into three groups: oil-free spray group where maintenance cleaner for air bearing handpieces was sprayed onto the dentin surface for 1 s and rinsed with water spray for 30 s; oil-containing spray group where maintenance cleaner for micro motor handpieces was sprayed onto the dentin surface for 1 s and rinsed with water spray for 30 s; and control group where the surface was rinsed with water spray for 30 s and then air-dried. These surfaces were then bonded with Clearfil SE Bond (Kuraray Medical, and resin composite (Clearfil AP-X, Kuraray Medical build-up crowns were incrementally constructed on the bonded surfaces. After storage for 24 h in 37°C water, the bonded teeth were sectioned into hour-glass shaped slices (0.7-mm thick perpendicular to the bonded surfaces. The specimens were then subjected to microtensile bond strength (μTBS testing at a crosshead speed of 1.0 mm/min. Data were analyzed with one-way ANOVA and the Tukey-Kramer test.Results: Maintenance spray-contaminated specimens (oil-free and oil-containing spray groups showed significantly lower μTBS than control specimens (P < 0.05. However, there was no significant difference between

  10. Optical properties of human radicular dentin: ATR-FTIR characterization and dentine tubule direction influence on radicular post adhesion

    Science.gov (United States)

    Quinto, Jose; Zamataro, Claudia B.; Benetti, Carolina; Dias, Derly A.; Blay, Alberto; Zezell, Denise Maria

    2015-06-01

    Knowledge of dental structures is essential for understanding of laser interaction and its consequences during adhesion processes. Tubule density in dentin ranges from 4.900 to 90.000 per mm2, for diameters from 1 to 3 μm. Light propagation inside the tubules is associated with tubules orientation. To the best of our knowledge, there is no previous work in literature characterizing physical-chemical alterations in dentin. The dentin samples were irradiated with a Er,Cr:YSGG Laser at wavelength 2.78 μm, with an energy density of 9.46 J/cm2 , above the ablation threshold. ATRFTIR at wavenumbers 2000 to 700 cm-1 was used to evaluate the differences among third root region and tubules orientation.

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

    Science.gov (United States)

    Dalby, Robert; Ellakwa, Ayman; Millar, Brian; Martin, F. Elizabeth

    2012-01-01

    Objectives. To examine the effect of immediate dentin sealing (IDS), with dentin bonding agents (DBAs) applied to freshly cut dentin, on the shear bond strength of etched pressed ceramic luted to dentin with RelyX Unicem (RXU) cement. Method. Eighty extracted noncarious third molars were ground flat to expose the occlusal dentin surfaces. The teeth were randomly allocated to five groups (A to E) of sixteen teeth each. Groups A to D were allocated a dentin bonding agent (Optibond FL, One Coat Bond, Single Bond, or Go!) that was applied to the dentin surface to mimic the clinical procedure of IDS. These specimen groups then had etched glass ceramic discs (Authentic) luted to the sealed dentin surface using RXU. Group E (control) had etched glass ceramic discs luted to the dentin surface (without a dentin bonding agent) using RXU following the manufacturer's instructions. All specimens were stored for one week in distilled water at room temperature and then shear stressed at a constant cross-head speed of 1 mm per minute until failure. Statistical analysis was performed by ANOVA followed by post hoc Tukey HSD method (P Optibond FL (Group A) and Go! (Group D). There was no statistical difference (P > 0.05) in the SBS between the test groups (A–D) or the control (group E). Conclusion. IDS using the dentin bonding agents tested does not statistically (P > 0.05) affect the shear bond strength of etched pressed ceramic luted to dentin with RXU when compared to the control. PMID:22287963

  12. Study of the areas and thicknesses of mesiobucal root canals prepared by three endodontic techniques Estudo das áreas e espessuras de canais radiculares mésio-vestibulares preparados por três técnicas endodônticas

    Directory of Open Access Journals (Sweden)

    Isa Geralda Teixeira Constante

    2007-06-01

    Full Text Available The purpose of this study was to compare, in vitro, by means of computerized analysis of digital radiographic images, the anatomic alterations produced in the mandibular molar tooth dentinal walls of mesiobucal canals with severe curvature by three different endodontic techniques: Progressive Preparation, Staged and Serial Preparation. A selection was made of 45 extracted, human, mandibular molars, with root curvatures greater than 25°. They were divided into three groups for every technique studied, which were then sub-divided into three sub-groups in accordance with the position of the curvature along the root: cervical, median or apical. After access surgery and tooth length determination, the canals were filled with 100% Barium Sulphate radiological contrast and the teeth were then radiographed with a direct digital radiography system, using a special apparatus capable of keeping the samples in the same spatial position during the different radiographic takes. After the above-mentioned endodontic techniques had been performed, the teeth were again filled with Barium sulphate and were also radiographed under the same previously mentioned conditions. The pre- and post-operative digital images were then analyzed in two computerized programs, AutoCAD 2004 and CorelDraw 10, to assess, respectively, the areas and the horizontal alterations which occurred in the internal and external walls of the root canals. The results indicated that although no significant differences among the techniques were shown in the statistical analysis, in a descriptive analysis the Progressive Preparation technique was shown to be more regular, uniform and effective.Objetivou-se comparar, in vitro, através de análise computadorizada de imagens radiográficas digitais, as alterações anatômicas promovidas nas paredes dentinárias de canais mésio-vestibulares com curvatura severa de molares inferiores por três técnicas endodônticas diferentes: Preparo Progressivo

  13. 21 CFR 872.3810 - Root canal post.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal post. 872.3810 Section 872.3810 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3810 Root canal post. (a) Identification. A root canal... of the platinum group intended to be cemented into the root canal of a tooth to stabilize and...

  14. A rapid non-destructive method for root dentin moisture measurements

    Science.gov (United States)

    Komabayashi, Takashi; Zhu, Qiang; Jiang, Jin; Safavi, Kamran E.; Spångberg, Larz S.W.

    2009-01-01

    Dentin moisture content is important in adhesive bonding and structural strength research. However, there is no rapid method available to assess dentin moisture without sample destruction. This study examined the use of a digital grain moisture meter to measure root dentin moisture in vitro. Extracted mandibular single rooted teeth were sectioned at the CEJ. The moisture of the root dentin was measured at six measuring modes for different grains and repeated five times. Dentin weight changes before and after drying were measured to obtain control values. The control values were compared with machine readings. In conclusion, (1) Each non-destructive measurement took less than 30 seconds. (2) 24 hours storage at 37°C and 100 % humidity did not restore dentin moisture. (3) Five grain modes had a high validity, and could be used for dentin moisture measurements. PMID:19157921

  15. 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.

  16. Fluorine analysis of human dentin surrounding resin composite after fluoride application by μ-PIGE/PIXE analysis

    OpenAIRE

    Okuyama, Katsushi; Komatsu, Hisanori; Yamamoto, Hiroko; Pereira, Patricia N. R.; Bedran-Russo, Ana K.; Nomachi, Masaharu; Sato, Takahiro; Sano, Hidehiko

    2011-01-01

    The use of fluoride for the prevention of caries is based on the transformation of hydroxylapatite to fluoroapatite in the presence of fluoride ions, thereby strengthening tooth structure. Adhesion of dentin and resin composite (tooth-colored restoration material) requires a dentin bonding system, since resin composite is not able to adhere to dentin directly. Demineralization of dentin by acid etching is an important step in the dentin bonding system; however, demineralization also introduce...

  17. Evaluation of three different agents for in-office treatment of dentinal hypersensitivity: A controlled clinical study

    OpenAIRE

    Shruti A Patil; Balaram D Naik; Suma, R.

    2015-01-01

    Context: Dentin desensitizers are used for in-office treatment of dentinal hypersensitivity. They block the open tubules and bring about a reduction in hypersensitivity. Aim: The aim was to evaluate and compare the clinical effectiveness of a dentin desensitizer, a combination of a dentin desensitizer + adhesive and one-bottle self-etching adhesive for in-office treatment of dentin hypersensitivity. Settings and Design: Institutional, prospective double-blind parallel clinical design....

  18. Microtensile dentin bond strength of fifth with five seventh-generation dentin bonding agents after thermocycling: An in vitro study

    OpenAIRE

    Bruhvi Poptani; K S Gohil; Jaishree Ganjiwale; Manisha Shukla

    2012-01-01

    Objectives: The objective of this in vitro study was to compare the microtensile dentin bond strength (μTBS) of five seventh-generation dentin bonding agents (DBA) with fifth-generation DBA before and after thermocycling. Materials and Methods: Ten extracted teeth were assigned to fifth generation control group (optibond solo) and each of the five experimental groups namely, Group I (G-Bond) ,Group II (S 3 Clearfil), Group III (One Coat 7.0), Group IV (Xeno V), and Group V (Optibond all in on...

  19. Comparison of Bacterial Leakage between 3 Different Root Canal Obturation Techniques in Oval Shaped Canals

    OpenAIRE

    Eshagh-ali Saberi; Shahram Shahraki; Sediqe Ebrahimipour; Anousheh Rashed Mohassel; Narjes Akbari; Majid Rezaei

    2014-01-01

    Introduction: The purpose of this study was to evaluate the sealing ability of 3 obturation techniques in oval-shaped canals by bacterial leakage assessment. Methods: Sixty mandibular incisors with oval canals were selected after providing buccolingual and mesiodistal radiographs. The teeth were sectioned at a 10 mm distance from the apex. After instrumentation, the teeth were divided into 3 groups and the canals in the three groups were obturated with lateral condensation (G1), warm vertical...

  20. Effect of Repeated Container Lid Opening on Dentin Shear Bond Strength of Two Dentin Adhesive Systems

    Directory of Open Access Journals (Sweden)

    H. Hassanzadeh

    2008-03-01

    Full Text Available Objective: Comparing the effect of repeated opening of the container lid of two dentin adhesive systems, Prime&Bond NT (P&B NT and iBond (iB, on shear bond strength.Materials and Methods: Intact bovine lower incisors (n=60, fixed in acrylic were ran-domly divided into six groups (n=10. Groups I and II were set as control groups. P&B NT and iB were applied on the samples after five days a week, three times a day for two weeks of use in groups III and VI; and after four weeks of use in groups V and VI. The samples were evaluated by a universal testing-machine (Instron, cross-head speed 1mm/min and stereomicroscope.Results: There was no significant difference between the bond strengths in any of the three P&B NT. The mean amount of the shear bond strength for iB after 60 times of use (15.31 MPa was significantly lowerthan that at the baseline (23.51 MPa. There was no significant difference between iB at the baseline and after 30 times of use (19.26 Mpa, and also between iB after 30 times of use and after 60 times of use. All P&B NT groups showed significantly highershear bond strengths when compared with their similar iB groups in iB.Conclusion: Repeated use (60 times of the all-in-one adhesive container seems to reduce dentin shear bond strength. Therefore, containers with a lower content of the same adhe-sive or a single-dose of the adhesive are preferred.

  1. 超声下不同根管冲洗剂组合对感染根管内粪肠球菌杀灭效果的研究%Antimicrobial effect of different root canal irrigant combinations on infected root canals under passive ultrasonic irrigation

    Institute of Scientific and Technical Information of China (English)

    张敏; 仇臖; 侯晖; 李琳; 周洁; 范晓敏

    2014-01-01

    AIM:To compare the antimicrobial effect of different root canal irrigant combinations under pas-sive ultrasonic irrigation in root canals.METHODS:90 human root canals contaminated with Enterococcus faecalis were randomly divided into 4 experimental groups (group A:25 g/L NaClO/20 g/L CHX,group B:25 g/L NaClO 30 mL/L H2 O2 ,group C:10 g/L NaClO 20 g/L CHX,group D:10 g/L NaClO/30 mL/L H2 O2 )and 2 two control groups (group E:52.5 g/L NaClO,group F:0.9%normal saline,n=10,5 were used as base line control).Before and after treatment bacterial content on the surface of root canal walls and at 100,200,300 μm in depth inside the dentinal tubules was measured and analyzed by means of one-way analysis of variance.RESULTS:On the surface and at different depths of dentine,the bactericidal efficiency of groups of A,B,C,D and E were significantly greater than that of group F (P0.05 )except at depth of 200 ~300um,the bactericidal efficiency of group A was lower than that of group E (P0.05).CONCLUSION:The combination of 25 g/L NaClO and 20 g/L CHX can be considered to be the ideal irrigant of root canal disinfection.%目的:比较超声作用下不同根管冲洗剂组合对根管内粪肠球菌的杀灭效果。方法:取粪肠球菌感染根管模型样本90个,随机分为6组(n=15),其中5个样本用于基线对照,10个样本分别按相应分组处理,A组:25 g/L次氯酸钠液液+20 g/L洗必泰液;B组:25 g/L次氯酸钠液+30 mL/L过氧化氢液;C组:10 g/L次氯酸钠液+20 g/L洗必泰液;D组:10 g/L次氯酸钠液+30 mL/L过氧化氢液;E组:52.5 g/L次氯酸钠液阳性对照;F组:生理盐水阴性对照。处理前后从样本的根管壁表面采样,并钻取不同深度牙本质进行细菌培养和计数。结果:A、B、C、D、E组根管壁表面及不同深度牙本质的细菌清除率均显著高于F组(P<0.05);对各层牙本质的细菌清除率,A组高于B、C、D组(P<0.05

  2. Antimicrobial effect of different root canal irrigant combinations on infected root canals under passive ultrasonic irrigation%超声下不同根管冲洗剂组合对感染根管内粪肠球菌杀灭效果的研究

    Institute of Scientific and Technical Information of China (English)

    张敏; 仇臖; 侯晖; 李琳; 周洁; 范晓敏

    2014-01-01

    AIM:To compare the antimicrobial effect of different root canal irrigant combinations under pas-sive ultrasonic irrigation in root canals.METHODS:90 human root canals contaminated with Enterococcus faecalis were randomly divided into 4 experimental groups (group A:25 g/L NaClO/20 g/L CHX,group B:25 g/L NaClO 30 mL/L H2 O2 ,group C:10 g/L NaClO 20 g/L CHX,group D:10 g/L NaClO/30 mL/L H2 O2 )and 2 two control groups (group E:52.5 g/L NaClO,group F:0.9%normal saline,n=10,5 were used as base line control).Before and after treatment bacterial content on the surface of root canal walls and at 100,200,300 μm in depth inside the dentinal tubules was measured and analyzed by means of one-way analysis of variance.RESULTS:On the surface and at different depths of dentine,the bactericidal efficiency of groups of A,B,C,D and E were significantly greater than that of group F (P0.05 )except at depth of 200 ~300um,the bactericidal efficiency of group A was lower than that of group E (P0.05).CONCLUSION:The combination of 25 g/L NaClO and 20 g/L CHX can be considered to be the ideal irrigant of root canal disinfection.%目的:比较超声作用下不同根管冲洗剂组合对根管内粪肠球菌的杀灭效果。方法:取粪肠球菌感染根管模型样本90个,随机分为6组(n=15),其中5个样本用于基线对照,10个样本分别按相应分组处理,A组:25 g/L次氯酸钠液液+20 g/L洗必泰液;B组:25 g/L次氯酸钠液+30 mL/L过氧化氢液;C组:10 g/L次氯酸钠液+20 g/L洗必泰液;D组:10 g/L次氯酸钠液+30 mL/L过氧化氢液;E组:52.5 g/L次氯酸钠液阳性对照;F组:生理盐水阴性对照。处理前后从样本的根管壁表面采样,并钻取不同深度牙本质进行细菌培养和计数。结果:A、B、C、D、E组根管壁表面及不同深度牙本质的细菌清除率均显著高于F组(P<0.05);对各层牙本质的细菌清除率,A组高于B、C、D组(P<0.05

  3. 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

  4. 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

  5. Shaping Ability of Reciproc, UnicOne, and Protaper Universal in Simulated Root Canals

    Directory of Open Access Journals (Sweden)

    Etevaldo Matos Maia Filho

    2015-01-01

    Full Text Available The study aimed to compare the shaping effects, preservation of the original curvature, and transportation of the apical foramen of Reciproc (VDW, Munich, Germany, UnicOne (Medin, Nové Město na Moravě, Czech Republic, and Protaper Universal (Dentsply Maillefer, Ballaigues, Switzerland in simulated root canals. Thirty resin blocks with simulated curved root canals were distributed into three groups (n=10, and prepared using Reciproc (RCp, UnicOne (UnO and the Protaper Universal (PTu. Standardized photographs were taken before and after the instrumentation, after which they were superimposed. Measurements were taken of the quantity of resin removed from the inner and outer walls of the curvature at 6 levels, the curvature angles before and after instrumentation, and the transportation of the apical foramen. RCp obtained the highest values for amount of resin removed from the inner wall while UnO demonstrated similar shaping on both the inner and outer walls. PTu produced the greatest transportation of foramen when compared to the reciprocating instruments. There was no significant difference between the groups in terms of the change in angle (P>0.05. All the instruments were capable of maintaining the original curvature of the root canal; however, the UnO, which used reciprocating movement, produced more conservative shapes with lower foramen transportation.

  6. K-file vs ProFiles in cleaning capacity and instrumentation time in primary molar root canals: An in vitro study

    Directory of Open Access Journals (Sweden)

    N Madan

    2011-01-01

    Full Text Available Objectives: This study compares the efficiency of manual K-files and rotary ProFiles in cleaning capacity and instrumentation time in primary molar root canals. Materials and Methods: Seventy-five maxillary and mandibular primary molar root canals were instrumented with ProFiles and K-files in the step-back manner from size #10 to #40. The teeth were decalcified, dehydrated and cleared, and analyzed for the presence of dye remaining on the root canal walls, which served as an evidence of cleaning capacity of both the techniques. Results: The results showed a significant difference in the cleaning capacity of the root canals with ProFiles and K-files, in apical and coronal thirds of the root canal. ProFiles have been found to be more efficient in cleaning the coronal thirds and K-files in cleaning apical thirds of the root canals. Both the techniques were almost equally effective in cleaning the middle thirds of the canals. The time taken during the cleaning of the root canals appeared to be statistically shorter with K-files than profiles.

  7. Root canal debris removal using different irrigating needles: An SEM study

    Directory of Open Access Journals (Sweden)

    Sheetal Ghivari

    2011-01-01

    Full Text Available Aim: This study was carried out to compare the efficacy of three irrigating needle designs in removal of debris from different parts of the root canal. Materials and Methods: Thirty human maxillary canines were prepared using HERO Shaper rotary system and irrigated with 1 ml of 5.25% sodium hypochlorite (NaOCl after each instrument change. Three 25-gauge irrigation needle designs - brush-covered Navi Tip FX (Group I, side-vented needle RC Twents (Group II and single-beveled (Group III irrigating needles - were tested for their efficiency in debris removal in three different parts of the root canal (n=10 canals per group. Following instrumentation, the roots were vertically sectioned and divided into coronal, middle and apical thirds for observation under scanning electron microscope (×200 magnification. Debris on the canal wall was evaluated by using a four-scale scoring system described by Paque and his co-workers. Results: The canals irrigated with brush-covered needle Navi Tip FX (Group I showed lower average debris score, indicating greater removal of debris in coronal third as compared to middle and apical thirds, whereas the canals irrigated with side-vented needle (Group II and single-beveled needle (Group III exhibited lower average score in the middle third than coronal and apical thirds. All the three needle designs exhibited higher debris score in apical third of the root canal. Tukey multiple comparisons test was applied at a significance level of P>0.05. A statistically significant difference (P<0.05 was observed in the debris removal in the coronal and middle thirds of root canals irrigated with brush-covered Navi Tip FX (Group I and side-vented (Group II needles, respectively, when compared with other needle design groups. Conclusion: Within the limitations of this study, it can be concluded that all the needle designs tested were effective in certain regions of the root canal with apical third uncleaned. Side-vented needle by

  8. MANAGEMENT OF LUMBAR SPINAL CANAL STENOSIS

    OpenAIRE

    Mukhergee G. S; Kiran Kumar L; Manikumar C. J

    2016-01-01

    BACKGROUND Spinal stenosis is one of the most common conditions in the elderly. It is defined as a narrowing of the spinal canal. The term stenosis is derived from the Greek word for narrow, which is “Stenos”. The first description of this condition is attributed to Antoine portal in 1803. Verbiest is credited with coining the term spinal stenosis and the associated narrowing of the spinal canal as its potential cause. [1-10] Kirkaldy–Willis subsequently described the de...

  9. Pain associated with root canal treatment

    OpenAIRE

    Segura-Egea, Juan José; Cisneros Cabello, Rafael; Llamas Carreras, José María; Velasco Ortega, Eugenio

    2009-01-01

    Our purpose was to determine the pain experienced by patients during root canal treatment and to correlate with age and gender, pulpal diagnosis, previous periapical status, dental characteristics and length of treatment. One hundred and seventy-six patients (68 men and 108 women), with ages ranged from 6 to 83 years, were randomly recruited. Patients completed a 10-cm visual analogue scale (VAS) that ranked the level of pain experienced during root canal treatment. The mean pain level during...

  10. Two root canals in maxillary central incisor

    Directory of Open Access Journals (Sweden)

    Fábio de Almeida Gomes

    2011-07-01

    Full Text Available Introduction and objective: The success of endodontic treatment requires the knowledge of tooth morphology and its variations. Case report: This clinical article reports an unusual root canal configuration that was detected in a maxillary central incisor with two root canals, demonstrated by radiographic and computerized tomography exams. Conclusion: Knowledge of endodontic anatomy as well as the obtainment of both preoperative radiographs and tomography is important to detect abnormal tooth morphology.

  11. Mechanics of the Panama Canal slides

    Science.gov (United States)

    Becker, George F.

    1917-01-01

    Dr. Becker visited the Canal Zone in 1913 as a geologist of the United States Geological Survey and since that time has given the problem the benefit of his study. His appointment as a member of the committee of the National Academy of Sciences has made it appropriate for his conclusions, based upon his personal observations and already reported in part to the Canal Commission, to be stated for the benefit of his associates and other American scientists and engineers.

  12. Compounded PHOSPHO1/ALPL deficiencies reduce dentin mineralization.

    Science.gov (United States)

    McKee, M D; Yadav, M C; Foster, B L; Somerman, M J; Farquharson, C; Millán, J L

    2013-08-01

    Phosphatases are involved in bone and tooth mineralization, but their mechanisms of action are not completely understood. Tissue-nonspecific alkaline phosphatase (TNAP, ALPL) regulates inhibitory extracellular pyrophosphate through its pyrophosphatase activity to control mineral propagation in the matrix; mice without TNAP lack acellular cementum, and have mineralization defects in dentin, enamel, and bone. PHOSPHO1 is a phosphatase found within membrane-bounded matrix vesicles in mineralized tissues, and double ablation of Alpl and Phospho1 in mice leads to a complete absence of skeletal mineralization. Here, we describe mineralization abnormalities in the teeth of Phospho1(-/-) mice, and in compound knockout mice lacking Phospho1 and one allele of Alpl (Phospho1(-/-);Alpl(+/-) ). In wild-type mice, PHOSPHO1 and TNAP co-localized to odontoblasts at early stages of dentinogenesis, coincident with the early mineralization of mantle dentin. In Phospho1 knockout mice, radiography, micro-computed tomography, histology, and transmission electron microscopy all demonstrated mineralization abnormalities of incisor dentin, with the most remarkable findings being reduced overall mineralization coincident with decreased matrix vesicle mineralization in the Phospho1(-/-) mice, and the almost complete absence of matrix vesicles in the Phospho1(-/-);Alpl(+/-) mice, whose incisors showed a further reduction in mineralization. Results from this study support prominent non-redundant roles for both PHOSPHO1 and TNAP in dentin mineralization.

  13. Ten-years degradation of resin-dentin bonds.

    Science.gov (United States)

    Hashimoto, Masanori; Fujita, Shinichi; Nagano, Futami; Ohno, Hiroki; Endo, Kazuhiko

    2010-08-01

    The purpose of this study was to evaluate the durability of resin-dentin bonds in 10-yr water-storage testing. Resin-dentin bonded bulk specimens were prepared using six commercially available resin adhesives. The resin-dentin bonded specimens were stored in water for 24 h (control group) or for 10 yr (experimental groups). After each storage period, the specimens were sectioned to make specimen beams and then subjected to a microtensile bond test. After the bond test, fractured surfaces were examined by scanning electron microscopy (SEM). In addition, interfacial observation of silver nanoleakage was performed using the backscatter electron mode of SEM. The bond strengths of four of the six adhesive systems tested decreased significantly after 10 yr. However, no significant bond-strength reduction was recorded for the other two systems. The interfacial observations showed water tree propagation in the bonding resin layer as a typical morphological change after aging for five of the six adhesives tested. Water tree propagation may be a symptom of degradation in the resin bonding layer of resin-dentin bonds. PMID:20662915

  14. APF and dentifrice effect on root dentin demineralization and biofilm

    NARCIS (Netherlands)

    G.C. Vale; C.P.M. Tabchoury; A.A. Del Bel Cury; L.M.A. Tenuta; J.M. ten Cate; J.A. Cury

    2011-01-01

    Because dentin is more caries-susceptible than enamel, its demineralization may be more influenced by additional fluoride (F). We hypothesized that a combination of professional F, applied as acidulated phosphate F (APF), and use of 1100-ppm-F dentifrice would provide additional protection for denti

  15. Bonding longevity of flowable GIC layer in artificially carious dentin

    NARCIS (Netherlands)

    T.K. Tedesco; C.C. Bonifácio; D. Hesse; C.J. Kleverlaan; T.L. Lenzi; D.P. Raggio

    2014-01-01

    Purpose To evaluate the bond longevity of glass ionomer cement (GIC) to sound and artificially carious dentin, using a high viscosity material with regular consistency and using a flowable GIC, after one year water storage. Material and methods Sixty bovine incisors were polished to obtain flat bucc

  16. Amalgam stained dentin: a proper substrate for bonding resin composite?

    NARCIS (Netherlands)

    J.D. Scholtanus

    2016-01-01

    Nowadays the use of dental amalgam is mostly abandoned and substituted by tooth colored resin composites that can be bonded to teeth tissues by adhesive techniques. The aim of this thesis was to find out whether dark stained dentin, as often observed after removal of amalgam restorations and attribu

  17. Assessment of dysplastic dentin in osteogenesis imperfecta and dentinogenesis imperfecta.

    Science.gov (United States)

    Malmgren, Barbro; Lindskog, Sven

    2003-04-01

    Two semiquantitative scoring systems, Clinical Radiographic Score (CRS) and Dysplastic Dentin Score (DDS), were introduced for analyzing degree of dysplastic manifestations in dentin. The utility of both systems was demonstrated in a large material of teeth from patients with dentinogenesis imperfecta (DI) and osteogenesis imperfecta (OI). Twenty teeth from healthy controls, 81 teeth from 40 patients with OI, and 18 teeth with DI without OI (DI type II) were examined. The degree of dysplasia was correlated with type and form of OI and type of DI. The median DDS did not differ between DI associated with OI (DI type I) and DI type II. DDS in OI patients without clinical signs of DI was above that of control teeth. Both circumpulpal and mantle dentin showed increased DDS, although circumpulpal dentin was more severely affected. The median DDS was highest for the most severe type of non-lethal OI (type III). DDS increased significantly with form (severity) of OI. A significant association between DDS and CRS was found, although diagnosis of DI in less severe cases was not possible based on radiographic or clinical signs alone. Thus, the DDS system proved valuable when the CRS system based on radiographic/clinical manifestations failed, the most significant finding being subclinical histological manifestations of DI in patients with OI but without clinical or radiographic signs of DI. These subtle dysplastic changes are most likely an expression of genetic disturbances associated with OI and should not be diagnosed as DI, but rather be termed histologic manifestations of dysplastic dentin associated with OI.

  18. Ablation of dentin by irradiation of violet diode laser

    Science.gov (United States)

    Hatayama, H.; Kato, J.; Akashi, G.; Hirai, Y.; Inoue, A.

    2006-02-01

    Several lasers have been used for clinical treatment in dentistry. Among them, diode lasers are attractive because of their compactness compared with other laser sources. Near-infrared diode lasers have been practically used for cutting soft tissues. Because they penetrate deep to soft tissues, they cause sufficiently thick coagulation layer. However, they aren't suitable for removal of carious dentin because absorption by components in dentin is low. Recently, a violet diode laser with a wavelength of 405nm has been developed. It will be effective for cavity preparation because dentin contains about 20% of collagen whose absorption coefficient at a violet wavelength is larger than that at a near-infrared wavelength. In this paper, we examined cutting performance of the violet diode laser for dentin. To our knowledge, there have been no previous reports on application of a violet laser to dentin ablation. Bovine teeth were irradiated by continuous wave violet diode laser with output powers in a range from 0.4W to 2.4W. The beam diameter on the sample was about 270μm and an irradiation time was one second. We obtained the crater ablated at more than an output power of 0.8W. The depth of crater ranged from 20μm at 0.8W to 90μm at 2.4W. Furthermore, the beam spot with an output power of 1.7W was scanned at a speed of 1mm/second corresponding to movement of a dentist's hand in clinical treatment. Grooves with the depth of more than 50μm were also obtained. From these findings, the violet diode laser has good potential for cavity preparation. Therefore, the violet diode laser may become an effective tool for cavity preparation.

  19. Removal action report on the Building 3001 canal at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    Oak Ridge National Laboratory (ORNL) is a federal facility managed by Lockheed Martin C, Energy Research, Inc., for the U.S. Department of Energy (DOE). ORNL on the Oak Ridge Reservation in East Tennessee at the Anderson and Roane County lines, approximately 38 km (24 miles) west of Knoxville, Tennessee, and 18 km (11 miles) southwest of downtown Oak Ridge. The Oak Ridge Graphite Reactor and its storage and transfer canal are located in Bldg. 3001 in the approximate center of Waste Area Grouping I in the ORNL main complex. 4:1 The Bldg. 3001 Storage Canal is an L-shaped, underground, reinforced-concrete structure running from the back and below the Graphite Reactor in Bldg. 3001 to a location beneath a hot cell in the adjacent Bldg. 3019. The Graphite Reactor was built in 1943 to produce small quantities of plutonium and was subsequently used to produce other isotopes for medical research before it was finally shut down in 1963. The associated canal was used to transport, under water, spent fuel slugs and other isotopes from the back of the reactor to the adjacent Bldg. 31319 hot cell for further processing. During its operation and years subsequent to operation, the canal`s concrete walls and floor became contaminated with radioisotopes from the water.This report documents the activities involved with replacing the canal water with a solid, controlled, low-strength material (CLSM) in response to a Comprehensive Environmental Response, Compensation, and Liability Act non-time-critical removal action.

  20. 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.

  1. Tensile bond strength of hydroxyethyl methacrylate (HEMA bonding agent to bovine dentine surface at various humidity

    Directory of Open Access Journals (Sweden)

    Adioro Soetojo

    2006-06-01

    Full Text Available One factor that make bonding agent adhere to dentine surface maximally is the humidity condition around the dentine surface. The best bond strength between bonding agent with dentine surface is depending on the moist surface. It mean that the dentine surface should neither too dry or wet. The objective of this research is to know the tensile bond strength of hydroxyethyl methacrylate (HEMA bonding agent to bovine dentine surface at various humidity. The bovine dentine was grounded to give flat surface, which was then etched with 37% phosphoric acid for 15 seconds. Dentine was washed with 20 ml water and dried with blot dry technique. The dentine, except the control group, was placed in a desiccator for one hour at difference humidity. Dentin was removed from desiccator, then covered with bonding agent and put into tensile tool plunger. Self-cured acrylic resin was applied on this bonding agent layer, which was placed on opposite-plunger. After 24 hours, tensile bond strength was measured with Autograph instrument. Data was statistically analyzed with One-Way ANOVA at 95% confidence level, continued with LSD test. Results of this study showed that 60%–90% humidity gave produce the lower of tensile bond strength of bonding agent to dentine surface (p ≤ 0.05. In conclusion, the treatment in 60% humidity gave the greatest tensile bond strength.

  2. Determination of elastic and plastic mechanical properties of dentin based on experimental and numerical studies

    Institute of Scientific and Technical Information of China (English)

    Xingguo LI; Bingbing AN; Dongsheng ZHANG

    2015-01-01

    The aim of this study is to investigate the change of mechanical properties of human dentin due to aging and spatial variation. Sections of coronal dentin are made from human molars in three groups: young, mid-aged, and old patients. A nanoindentation test is conducted from regions near the pulp to the dentin-enamel junction (DEJ) to evaluate the load-depth indentation response and determine Young’s modulus and hardness. Based on the loading and unloading load-displacement curves in nanoindentation, a numerical model of plastic damage is used to study the plastic and the damage behaviors and the contribution to the degradation in the unloading stiffness. The experimental results show that Young’s modulus of the inner dentin is significantly lower than that of outer dentin in each age group. Compared with the young dentin, the old dentin has greater hardness and Young’s modulus with similar spatial variations. The magnitudes of the yield strength and the damage variable are also affected by aging and vary with spatial locations. In the same age group, the yield strength in inner dentin is lower than those in middle and outer dentin, more damage occurs with similar spatial variations, and the yield strength of young dentin is generally lower and causes more damage compared with those in both the mid-aged and old groups.

  3. Effect of Different Irrigating Solutions and Endodontic Sealers on Bond Strength of the Dentin - Post Interface with and without Defects

    Directory of Open Access Journals (Sweden)

    Felice R. Grassi, Carmine Pappalettere, Mariasevera Di Comite, Massimo Corsalini, Giorgio Mori, Andrea Ballini, Vito Crincoli, Francesco Pettini, Biagio Rapone, Antonio Boccaccio

    2012-01-01

    Full Text Available Aims. To investigate how the interfacial shear strength of the dentin - post interface with and without defects changes for different combinations irrigant/sealer.Methods. In forty human decoronated and instrumented teeth, fibreglass posts were inserted. The obtained root segments were randomly assigned to four different groups according to the irrigant adopted and the cement used to seal the root canal. The root segments were processed for metyl-methacrylate embedding. Serial sections were obtained and submitted to histomorphometric analyses in order to observe any defect of adhesion at the dentin - post interface and to measure the defects' dimension. The serial sections were also submitted to micro-push-out test. The measured shear strength values were subjected to statistical analysis by one-way ANOVA. The values of bond strength determined for the defective samples were correlated with the dimension of the defects. Finite element models were built to interpret and corroborate the experimental findings.Results. ANOVA showed that the generic combination irrigant/sealer does not affect the interfacial shear strength values. The bond strength of the samples without defects was averagely twice as large as that of the defective samples. The defects occupying more than 12 % of the total transverse section area of the endodontic cement layer led to a reduction of the bond strength of about 70 %. The predictions of the finite element models were in agreement with the experimental results.Conclusion. Defects occupying less than 2 % of the total transverse section area of the cement layer were shown to be acceptable as they have rather negligible effects on the shear strength values. Technologies/protocols should be developed to minimize the number and the size of the defects.

  4. Posterior semicircular canal dehiscence: a morphologic cause of vertigo similar to superior semicircular canal dehiscence

    Energy Technology Data Exchange (ETDEWEB)

    Krombach, G.A.; Schmitz-Rode, T.; Haage, P.; Guenther, R.W. [Department of Diagnostic Radiology, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); DiMartino, E. [Department of Otorhinolaryngology, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); Prescher, A. [Department of Anatomy, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); Kinzel, S. [Department of Experimental Veterinarian Medicine, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany)

    2003-06-01

    Heading Abstract.The aim of this study was to assess imaging findings of posterior semicircular dehiscence on computed tomography and to evaluate incidence of posterior and superior semicircular canal dehiscence in patients presenting with vertigo, sensorineuronal hearing loss or in a control group without symptoms related to the inner ear. Computed tomography was performed in 507 patients presenting either with vertigo (n=128; 23 of these patients suffered also from sensorineuronal hearing loss), other symptoms related to the inner ear, such as hearing loss or tinnitus (n=183) or symptoms unrelated to the labyrinth (n=196). All images were reviewed for presence of dehiscence of the bone, overlying the semicircular canals. Twenty-nine patients had superior semicircular canal dehiscence. Of these patients, 83% presented with vertigo, 10% with hearing loss or tinnitus and the remaining 7% with symptoms unrelated to the inner ear. In 23 patients dehiscence of the posterior semicircular canal was encountered. Of these patients, 86% presented with vertigo, 9% with hearing loss or tinnitus and 5% with symptoms unrelated to the inner ear. Defects of the bony overly are found at the posterior semicircular canal, in addition to the recently introduced superior canal dehiscence syndrome. Significant prevalence of vertigo in these patients suggests that posterior semicircular canal dehiscence can cause vertigo, similar to superior semicircular canal dehiscence. (orig.)

  5. An in vitro model to investigate filling of lateral canals.

    Science.gov (United States)

    Venturi, Mauro; Di Lenarda, Roberto; Prati, Carlo; Breschi, Lorenzo

    2005-12-01

    Aims of this work were to examine lateral canals in extracted teeth, to propose a new technique to produce artificial lateral canals, and to compare two obturation techniques. Cleared roots were examined to record measure and shape of lateral canals. Artificial lateral canals were prepared on human demineralized teeth before final clearing. Specimens were divided in two groups: canals of group 1 were filled with Schilder's technique, canals of group 2 were filled with vertical compaction with apical backfilling. Stereomicroscopic analysis of lateral canal filling revealed lower filling rates in apical canals compared to coronal ones and higher filling rates with "vertical compaction with apical backfilling" compared to Schilder's group. The tested procedure appears to be a reliable technique to obtain standardized lateral canals and to compare filling procedures.

  6. The comparison between two irrigation regimens on the dentine wettability for an epoxy resin based sealer by measuring its contact angle formed to the irrigated dentine

    Directory of Open Access Journals (Sweden)

    Rayapudi Phani Mohan

    2015-01-01

    Conclusion: An irrigation regimen consisting of NaOCl with either EDTA or EDTAC solution as a final irrigant influences the dentine wettability and contact angle of a sealer. EDTAC as a final irrigant facilitates better dentin wettability than EDTA for AH Plus to promote its better flow and adhesion.

  7. THE INFLUENCE OF AIR-DRYING ON HYPER-REMINERALIZATION OF DEMINERALIZED DENTIN - A STUDY ON BULK AS WELL AS ON THIN WET SECTION OF BOVINE DENTIN

    NARCIS (Netherlands)

    INABA, D; IIJIMA, Y; TAKAGI, O; RUBEN, J; ARENDS, J

    1995-01-01

    The influence of air-drying on the remineralization of demineralized bovine dentine was examined in wet bulk samples, in dried bulk samples as well as in wet thin sections. Bulk samples of bovine dentine were first demineralized in an acidic gel (pH = 5) at 37 degrees C for 3 weeks. After 24-hour pr

  8. Sealing of adhesive systems in ferric sulfate-contaminated dentinal margins in class V composite resin restorations

    Science.gov (United States)

    Shadman, Niloofar; Farzin Ebrahimi, Shahram; Mollaie, Najmeh

    2016-01-01

    Background. Hemostatic agents are applied to prepare an isolated bleeding-free condition during dental treatments and can influence adhesive restorations. This study evaluated the effect of a hemostatic agent (ViscoStat) on microleakage of contaminated dentinal margin of class V composite resin restorations with three adhesives. Methods. Sixty freshly extracted human molars were selected and class V cavities (3×3×1.5 mm) were prepared on buccal and lingual surfaces. Gingival margins of the cavities were placed below the cementoenamel junction. The teeth were divided into six groups randomly. The adhesives were Excite, AdheSE and AdheSE One. In three groups, the gingival walls of the cavities were contaminated with ViscoStat and then rinsed. The cavities were restored with composite resin and light-cured. After storage in distilled water (37°C) for 24 hours and polishing, the samples were thermocycled and sealed with nail varnish. Then they were stored in 1% basic fuchsin for 24 hours, rinsed and mounted in self-cured acryl resin, followed by sectioning buccolingually. Dye penetration was observed under a stereomicroscope and scored. Data were statistically analyzed with Kruskal-Wallis and Mann-Whitney U tests. Peffects on dentin microleakage (P > 0.05). In the contaminated groups, Excite had significantly less microleakage than the others (P = 0.003). AdheSE and AdheSE One did not exhibit significant difference in microleakage (P > 0.05). Conclusion. ViscoStat hemostatic agent increased dentinal microleakage in AdheSE and AdheSE One adhesives with no effect on Excite. PMID:27092210

  9. Radiological Review Studies On Ismailia Canal Ecology

    International Nuclear Information System (INIS)

    The present work is a brief review of pr-studies carried out on Ismailia Canal, Egypt, water ecosystem. Ismailia Canal water body is a bicarbonate stream with slight seasonal variations in its water chemical constituents. The canal water pH in all the stream locations are below 8.3 with low suspended matter(SM) content (22-33 mg.l-1). The mineralogical analysis of the canal bottom sediments consist mainly of quartz, smectite and kaolinite minerals. The γ- spectroscopic identification showed traces of naturally occurring radio nuclides (238U, 232Th and 40K). The average activity level of the dry samples ranged from 12 to 89 Bq.Kg-1 for the detected natural radio nuclides. Some parameters affected the sorption behaviour of radio nuclides on suspended matters and bottom sediments; such as solution pH, SM concentration, sediment grain size, carrier concentration and competing ions were studied. The reaction rates were investigated for each radionuclide studied. The distribution of the studied radio nuclides, between the liquid phase and the sediments phase was investigated, for both flowing and static systems. For both flowing and non-flowing (static), the depth penetration of the studied radio nuclides within the bottom sediment layers were found to vary from one radionuclide to the other. The total capacities of bottom sediments and the suspended matter were found to be low. As Ismailia Canal is an important source of water for public domestic uses, irrigation animals and the aquatic species; these situations have led to state that it is not recommended to release any liquid radioactive wastes to this canal. Furthermore, periodical radiometric analysis for the canal water and its components should be carried out.

  10. CBCT assisted diagnosis and treatment of mandibular canine with apical periodontitis and double root canals in a case%CBCT 辅助诊断、治疗左下颌尖牙双根管根尖周炎1例

    Institute of Scientific and Technical Information of China (English)

    田李静; 彭冬; 张贤华

    2015-01-01

    报道1例在 CBCT 辅助下诊断和治疗的左下颌尖牙双根管病例。CBCT 能够三维显示根管的形态和分布,在术前术中对根管变异作出明确的诊断,对防止根管遗漏、保存牙本质和保障根管治疗成功有一定的临床指导意义。%A case of mandibular canine with apical periodontitis and double root canals was treated by CBCT assisted diagnosis and root ca-nal therapy.CBCT distinctly demonstrated the morphology of the root canal system in three dimensions and provided the information of canal varieties,prevented missed canals and conserved dentin.CBCT can guarantee the success of root canal therapy for the tooth with canal vareties.

  11. Influence of alveolar bone level on the pull-out bond strength of fiber-reinforced composite posts to root dentin.

    Science.gov (United States)

    Dal Piva, Amanda Maria de Oliveira; Campos, Fernanda; Alves, Maria Luiza Lima; Sousa, Rafael Santiago; Lima, Júlia Magalhães da Costa; Souza, Rodrigo Othávio Assunção

    2016-01-01

    This in vitro study evaluated the influence of alveolar bone level and type of cement on pull-out bond strength between different fiber-reinforced composite (FRC) posts and root dentin. Sixty bovine teeth were sectioned, and their root canals were prepared. The specimens were divided into 6 groups (n = 10) according to 2 factors: alveolar bone level and type of cement. Each root was embedded in acrylic resin to the depth of 7, 10, or 14 mm, simulating different alveolar bone levels. After the FRC posts were treated with 37% phosphoric acid and silane was applied, they were cemented with either a conventional resin cement or a self-adhesive resin cement and subjected to mechanical cycling. The results indicated that neither the alveolar bone level nor the type of cement played a significant role in the pull-out bond strength of the FRC posts to root dentin. Therefore, it is concluded that conventional and self-adhesive resin cements can be used to lute FRC posts to tooth roots, even in the presence of significant alveolar bone resorption. PMID:26943098

  12. Effect of Resin Cement Porosity on Retention of Glass-Fiber Posts to Root Dentin: An Experimental and Finite Element Analysis.

    Science.gov (United States)

    Da Silva, Natércia Rezende; Aguiar, Grazielle Crystine Rodrigues; Rodrigues, Monise de Paula; Bicalho, Aline Aredes; Soares, Priscilla Barbosa Ferreira; Veríssimo, Crisnicaw; Soares, Carlos José

    2015-01-01

    The aim of this study was to evaluate the effect of porosity of self-adhesive resin on the stress distribution, post retention and failure mode of fiber post cemented to human root dentin. Ten human central upper incisors with circular root canal were selected. They were sectioned with 15 mm and were endodontically filled. The roots were scanned using micro-CT after post space preparation for root filling remaining evaluation. Fiber posts were cemented using self-adhesive resin cement (Rely X U200, 3M-ESPE). Two 1-mm-thick slices from the cervical, medium and apical thirds were scanned for resin cement bubbles volume measurements and submitted to a push-out test (PBS). Three operators using stereomicroscopy and confocal laser microscopy classified the failure mode. Stress distributions during the push-out test were analyzed using 3D finite element analysis. PBS values (MPa) were submitted to one-way ANOVA and Tukey's post hoc tests and the failure modes using the Kappa coefficient to assess inter-operator agreement. Chi-square test was used to determine significant differences between the methods ( = 0.05). Push-out bond strength was significantly affected by the bubbles presence in all root depth (pstress concentration was higher when the bubbles were present. Adhesive dentin/resin cement interface failure was the most frequent type of failure. Confocal microscopy was better than stereomicroscopy for failure analysis. Bubbles generated during resin cement insertion into the root canal negatively affect the stress distribution and the bond strength. The use of confocal microscopy is recommended for failure analysis. PMID:26963208

  13. Effect of Different Obturation Materials on Residual Antimicrobial Activity of 2% Chlorhexidine in Dentin at Different Time Intervals: An Ex Vivo Study

    Directory of Open Access Journals (Sweden)

    Behnam Bolhari

    2016-03-01

    Full Text Available Objectives: The aim of this study was to evaluate the effect of gutta percha/AH26 and Resilon/RealSeal SE on residual antimicrobial activity of chlorhexidine (CHX in human root dentin and suggest the best filling material when CHX is used as final irrigant.Materials and Methods: One-hundred and forty-four single-rooted human teeth were selected for this study. Canals were instrumented to the apical size #35. Smear layer was removed using 5.25% NaOCl and 17% EDTA and then 108 teeth were irrigated with 2% CHX and randomly divided into three groups of gutta percha/AH26, Resilon/RealSeal SE and positive controls. Each group was divided into three subgroups for different time intervals (one, three and six weeks. Thirty-six teeth, as negative controls, were irrigated with saline and obturated with gutta percha/AH26 and Resilon/RealSeal SE. Dentin powder was prepared at the afore-mentioned intervals. After exposure to Enterococcus faecalis for 24 hours, colony forming units (CFUs were counted and residual antimicrobial activity was calculated. The data were analyzed using the Kruskal Wallis test and one-way ANOVA. The significance level was set at P<0.05.Results: The antimicrobial activity of CHX gradually decreased in a time-dependent manner but it maintained over 95% of its antimicrobial activity after six weeks. Moreover, Resilon/RealSeal SE significantly decreased the antimicrobial activity of CHX in comparison with gutta-percha/AH26 (P<0.05.Conclusion: After a final irrigation with CHX, gutta-percha/AH26 is a better choice for root canal obturation.Key words: Chlorhexidine; Gutta-Percha; Epoxy resin AH-26; Resilon sealer. 

  14. Traumatic facial nerve palsy: CT patterns of facial nerve canal fracture and correlation with clinical severity

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jae Cheol; Kim, Sang Joon; Park, Hyun Min; Lee, Young Suk; Lee, Jee Young [College of Medicine, Dankook Univ., Chonan (Korea, Republic of)

    2002-07-01

    To analyse the patterns of facial nerve canal injury seen at temporal bone computed tomography (CT) in patients with traumatic facial nerve palsy and to correlate these with clinical manifestations and outcome. Thirty cases of temporal bone CT in 29 patients with traumatic facial nerve palsy were analyzed with regard to the patterns of facial nerve canal involvement. The patterns were correlated with clinical grade, the electroneurographic (ENoG) findings, and clinical outcome. For clinical grading, the House-Brackmann scale was used, as follows:grade I-IV, partial palsy group; grade V-VI, complete palsy group. The electroneuronographic findings were categorized as mild to moderate (below 90%) or severe (90% and over) degeneration. In 25 cases, the bony wall of the facial nerve canals was involved directly (direct finding): discontinuity of the bony wall was onted in 22 cases, bony spicules in ten, and bony wall displacement in five. Indirect findings were canal widening in nine cases and adjacent bone fracture in two. In one case, there were no direct or indirect findings. All cases in which there was complete palsy (n=8) showed one or more direct findings including spicules in six, while in the incomplete palsy group (n=22), 17 cases showed direct findings. In the severe degeneration group (n=13), on ENog, 12 cases demonstrated direct findings, including spicules in nine cases. In 24 patients, symptoms of facial palsy showed improvement at follow up evaluation. Four of the five patients in whom symptoms did not improve had spicules. Among ten patients with spicules, five underwent surgery and symptoms improved in four of these; among the five patients not operated on , symptoms did not improve in three. In most patients with facial palsy after temporal bone injury, temporal bone CT revealed direct or indirect facial nerve canal involvement, and in complete palsy or severe degeneration groups, there were direct findings in most cases. We believe that meticulous

  15. Matrix metalloproteinase 20-dentin sialophosphoprotein interaction in oral cancer.

    Science.gov (United States)

    Saxena, G; Koli, K; de la Garza, J; Ogbureke, K U E

    2015-04-01

    Matrix metalloproteinase 20 (MMP-20), widely regarded as tooth specific, participates with MMP-2 in processing dentin sialophosphoprotein (DSPP) into dentin sialoprotein, dentin phosphoprotein, and dentin glycoprotein. In biochemical system, MMP-2, MMP-3, and MMP-9 bind with high affinity to, and are activated by, specific small integrin-binding ligand N-linked glycoproteins (SIBLINGs): bone sialoprotein, osteopontin, and dentin matrix protein 1, respectively. Subsequent reports documented possible biological relevance of SIBLING-MMP interaction in vivo by showing that SIBLINGs are always coexpressed with their MMP partners. However, the cognate MMPs for 2 other SIBLINGs-DSPP and matrix extracellular phosphogylcoprotein-are yet to be identified. Our goal was to investigate MMP-20 expression and to explore preliminary evidence of its interaction with DSPP in oral squamous cell carcinomas (OSCCs). Immunohistochemistry analysis of sections from 21 cases of archived human OSCC tissues showed immunoreactivity for MMP-20 in 18 (86%) and coexpression with DSPP in all 15 cases (71%) positive for DSPP. Similarly, 28 (93%) of 30 cases of oral epithelial dysplasia were positive for MMP-20. Western blot and quantitative real-time polymerase chain reaction analysis on OSCC cell lines showed upregulation of MMP-20 protein and mRNA, respectively, while immunofluorescence showed coexpression of MMP-20 and DSPP. Colocalization and potential interaction of MMP-20 with dentin sialoprotein was confirmed by coimmunoprecipitation and mass spectrometry analysis of immunoprecipitation product from OSCC cell lysate, and in situ proximity ligation assays. Significantly, results of chromatin immunoprecipation revealed a 9-fold enrichment of DSPP at MMP-20 promoter-proximal elements. Our data provide evidence that MMP-20 has a wider tissue distribution than previously acknowledged. MMP-20-DSPP specific interaction, excluding other MMP-20-SIBLING pairings, identifies MMP-20 as DSPP cognate MMP

  16. Effect of intracoronal bleaching agents on ultrastructure and mineral content of dentin

    Directory of Open Access Journals (Sweden)

    Fatemeh Maleknejad

    2012-01-01

    Full Text Available Aim: The purpose of this in vitro study was to evaluate the ultrastructural changes of dentin induced after exposure to different intracoronal tooth bleaching agents. Materials and Methods: Dental discs of 1 mm thickness were prepared from coronal dentin of sixty-four human maxillary premolars. Experimental specimens were divided into four subgroups: 45% carbamide peroxide, 35% hydrogen peroxide, sodium perborate + 30% hydrogen peroxide, sodium perborate + water. The specimens were then evaluated under scanning electron microscope to determine diameter of dentinal tubules and chemical analysis. Results: There was significant difference between dentinal tubule diameter of all test and control groups with the exception of sodium perborate + water. Chemical analysis revealed that there was no significant difference between experimental subgroups regarding calcium and sulfur wt%. Conclusions: All bleaching agents increased dentinal tubule diameter and promote alterations in mineral content of dentin with the exception of Sodium perborate mixed with water.

  17. Splicing site mutations in dentin sialophosphoprotein causing dentinogenesis imperfecta type II.

    Science.gov (United States)

    Holappa, Heidi; Nieminen, Pekka; Tolva, Liisa; Lukinmaa, Pirjo-Liisa; Alaluusua, Satu

    2006-10-01

    Dentinogenesis imperfecta (DGI) type II (OMIM # 125490) is an inherited disorder affecting dentin. Defective dentin formation results in discolored teeth that are prone to attrition and fracture. To date, several mutations have been described in the dentin sialophosphoprotein (DSPP) gene, causing DGI types II and III and dentin dysplasia type II. DSPP encodes two proteins: dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). Here, we describe a mutational analysis of DSPP in seven Finnish families with DGI type II. We report two mutations and five single nucleotide polymorphisms. In one family we found a mutation that has been described earlier in families with different ethnicity, while in six families we found a novel g.1194C>A (IVS2-3) transversion. Bioinformatic analysis of known DSPP mutations suggests that DGI type II is usually caused by aberration of normal splicing.

  18. The effect of dentin primer on the shear bond strength between composite resin and enamel.

    Science.gov (United States)

    Hadavi, F; Hey, J H; Ambrose, E R; Louie, P W; Shinkewski, D J

    1993-01-01

    The purpose of this study was to determine the effect of accidental dentin primer contact with etched enamel on shear bond strength of composite resin to enamel. Four dentin bonding systems were included in this study: GLUMA Dentin Bond, Scotchbond, and Prisma Universal Bond 2 and 3. Eighty extracted human permanent anterior teeth were used and divided in eight test groups. The vestibular surfaces were ground and acid etched. For each dentin bonding system 10 samples were treated with dentin primer prior to placement of resin. Shear bond testing showed that enamel contact with dentin primer in the above two systems decreased the shear bond strength between composite and enamel by 31 to 44%. PMID:8337183

  19. The Kra Canal and Southeast Asian Relations

    Directory of Open Access Journals (Sweden)

    Rini Suryati Sulong

    2012-01-01

    Full Text Available This paper is a conceptual study that attempts to analyse the possible effects of the development of the Kra Isthmus Canal on ASEAN relations. The Kra Canal would constitute a mega-project, a passageway that would connect the Andaman Sea and the Gulf of Thailand at the Isthmus of Kra, Thailand. Although the proposed Kra Canal is projected to provide many economic and trade benefits to Thailand, and to the region as a whole, steps toward its development have yet to be taken. There has been much debate over the costs for trade, the costs for the environment, national and regional security concerns, as well as major concerns related to political and economic relations in the region. Therefore, one of the main purposes of this study is to contribute to the debate on the possible impact of the devel-opment of the Kra Canal on ASEAN’s regional relations. In particular, it proposes that the development of the Kra Canal could threaten regional solidarity as it would physically divide maritime Southeast Asia from main-land Southeast Asia, which would ultimately result in an economic, cultural and political divide of ASEAN itself.

  20. Cytotoxicity evaluation of a new self-adhering flowable composite by dentin barrier test

    OpenAIRE

    Ülker, Hayriye Esra; Ülker, Mustafa; Özcan, Erhan

    2013-01-01

    OBJECTIVE: The aim of this study was to evaluate the cytotoxicity of a new self-adhering flowable composite (Vertise Flow) in a dentin barrier test device using three-dimensional cultures of bovine dental pulp derived cells.MATERIALS AND METHOD: Artificial cell culture perfusion chambers were separated into two compartments using a 500 µm dentin disc. In the lower compartment, a pulp chamber was created by placing the three-dimensional cultures onto the dentin disc. Test materials were introd...

  1. In Vitro Ability of a Novel Nanohydroxyapatite Oral Rinse to Occlude Dentine Tubules

    OpenAIRE

    Hill, Robert G.; Xiaohui Chen; David G. Gillam

    2015-01-01

    Objectives. The aim of the study was to investigate the ability of a novel nanohydroxyapatite (nHA) desensitizing oral rinse to occlude dentine tubules compared to selected commercially available desensitizing oral rinses. Methods. 25 caries-free extracted molars were sectioned into 1 mm thick dentine discs. The dentine discs (n = 25) were etched with 6% citric acid for 2 minutes and rinsed with distilled water, prior to a 30-second application of test and control oral rinses. Evaluation was ...

  2. A Study of the Genetics and Physical Properties of Dentine Defects

    OpenAIRE

    Mohamed Ibrahim, N. B.

    2013-01-01

    Dentinogenesis Imperfecta (DI) and Dentine Dysplasia (DD) are rare inherited condition affecting the dentine. Previous studies have reported the histological presentation of teeth with dentine defects but the differences between clinical appearances and physical properties, and how do they link to the underlying gene defects, is limited. In addition, the differences between primary and permanent teeth are poorly understood. Aim and Objective: The aim of this study was to investigate if there ...

  3. Is diagnosing exposed dentine a suitable tool for grading erosive loss?

    OpenAIRE

    Holbrook, W. Peter; Ganss, Carolina

    2008-01-01

    Quantifying tooth wear in general and erosion in particular mostly is made by distinguishing between lesions restricted to enamel and lesions reaching the underlying dentine. Various scores for grading have been used, but in all systems, higher scores are given in cases of exposed dentine, thus, indicating a more severe stage of the condition. Clinical diagnosis of exposed dentine is made by assessing changes in colour or optical properties of the hard tissues. This paper aims to review the l...

  4. Diffusion of peroxides through dentine in vitro with and without prior use of a desensitizing varnish

    OpenAIRE

    Hannig, Christian; Weinhold, Hans; Becker, Klaus; Attin, Thomas

    2010-01-01

    Different bleaching regimens are used in dentistry possibly penetrating the dentine and affecting the pulp. The aim of the present study was to investigate peroxide diffusion through dentine pre-treated with a desensitizing varnish (Vivasens®) in a standardized in vitro setup during application of different bleaching materials. The penetration was tested using 1.3-mm-thick bovine dentine slabs. The following bleaching materials were tested with and without prior application of the desensitizi...

  5. Diffusion of peroxides through dentine in vitro with and without prior use of a desensitizing varnish

    OpenAIRE

    Hannig, C; Weinhold, H C; Becker, K.; Attin, T.

    2011-01-01

    Different bleaching regimens are used in dentistry possibly penetrating the dentine and affecting the pulp. The aim of the present study was to investigate peroxide diffusion through dentine pre-treated with a desensitizing varnish (Vivasens®) in a standardized in vitro setup during application of different bleaching materials. The penetration was tested using 1.3-mm-thick bovine dentine slabs. The following bleaching materials were tested with and without prior application of the desensitizi...

  6. Effect of interchanging two composite resin system with a dentine adhesive.

    OpenAIRE

    Henderson L; Soh G

    1990-01-01

    There is a tendency to interchange dentine adhesives and composite resins when using composite resins for restorations. This study used marginal contraction gaps to test the effect of changing composite resins with a dentine adhesive. Cylindrical butt-joint cavities were prepared entirely in dentine using extracted human teeth. Two groups of control cavities (30 cavities per group) were restored with Prisma-Bond/Prisma-Fil and Heliobond/Heliomolar respectively. Two groups of test cavities (30...

  7. A Case of Dentin Dysplasia with Full Mouth Rehabilitation: A 3-year Longitudinal Study

    OpenAIRE

    Khandelwal, Suneet; Gupta, Dheeraj; Likhyani, Lalit

    2014-01-01

    ABSTRACT Dentin dysplasia, a rare hereditary disorder of dentin formation, is characterized by normal enamel but atypical dentin formation along with abnormal pulpal morphology. It is inherited as an autosomal dominant trait. It has been divided into two clinical entities: type I (radicular) and type II (coronal). Early diagnosis and initiation of effective regular dental treatments may help the patients with this condition to delay or prevent the loss of the entire dentition and help them in...

  8. Effect of phytic acid, ethylenediaminetetraacetic acid, and chitosan solutions on microhardness of the human radicular dentin

    OpenAIRE

    Vineeta Nikhil; Shikha Jaiswal; Parul Bansal; Rohit Arora; Shalya Raj; Pulkit Malhotra

    2016-01-01

    Aim: The purpose of this study was to evaluate the effect of phytic acid, ethylenediaminetetraacetic acid (EDTA), and chitosan solutions on the microhardness of human radicular dentin. Materials and Methods: Thirty dentin specimens were randomly divided into three groups of 10 specimens each according to the irrigant used: G1 - 1% phytic acid, G2 - 17% EDTA, and G3 - 0.2% chitosan. A standardized volume of each chelating solution was used for 3 min. Dentin microhardness was measured befo...

  9. Comparative efficacy of two treatment modalities for dentinal hypersensitivity: A clinical trial

    OpenAIRE

    Aparna S; Setty Swati; Thakur Srinath

    2010-01-01

    Background: Dentin hypersensitivity is a recurrent condition causing discomfort and sometimes pain to the patient, which also deters him from maintaining adequate oral hygiene. Home care and office measures are used for treatment of this malady. Aim: To evaluate and compare the efficacy of 2 treatment modalities for dentinal hypersensitivity, iontophoresis with acidulated phosphate gel (APF) gel, and dentin-bonding agent application. Materials and Methods: This split mouth randomized clinic...

  10. Synchronous rectal adenocarcinoma and anal canal adenocarcinoma

    Institute of Scientific and Technical Information of China (English)

    GU Jin; LI Jiyou; YAO Yunfeng; LU Aiping; WANG Hongyi

    2007-01-01

    It is difficult to distinguish a tectal carcinoma with anal metastases from coexistent synchronous anorectal carcinomas.The therapeutic strategy for rectal and anal carcinoma is so different that it should be clearly identified.Here,we report on the case of a 63-year-old man who presented with an upper-third rectal adenocarcinoma.Five months after resection,he developed an adenocarcinoma in the anal canal.The histological slides of both tumors were reviewed and immunohistochemical studies for cytokeratins(CKs)7 and 20 were performed.The index tumor demonstrated CK 7-/CK 20+and the second showed CK7+/CK20+.For this reason,we believe the present case had synchronous adenocarcinomas arising from anal canal and the rectum separately.It is very important to difierentiate the anorectal lesions pathologically because of the impact on the therapeutic options available,especially for the lesion arising in the anal canal.

  11. File list: His.CDV.50.AllAg.Atrioventicular_canals [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  12. File list: Unc.CDV.05.AllAg.Atrioventicular_canals [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.CDV.05.AllAg.Atrioventicular_canals mm9 Unclassified Cardiovascular Atrioventicular canal...s http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.CDV.05.AllAg.Atrioventicular_canals.bed ...

  13. File list: His.CDV.05.AllAg.Atrioventicular_canals [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.CDV.05.AllAg.Atrioventicular_canals mm9 Histone Cardiovascular Atrioventicular canal...s http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.CDV.05.AllAg.Atrioventicular_canals.bed ...

  14. File list: Unc.CDV.50.AllAg.Atrioventicular_canals [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.CDV.50.AllAg.Atrioventicular_canals mm9 Unclassified Cardiovascular Atrioventicular canal...s http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.CDV.50.AllAg.Atrioventicular_canals.bed ...

  15. File list: Unc.CDV.10.AllAg.Atrioventicular_canals [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.CDV.10.AllAg.Atrioventicular_canals mm9 Unclassified Cardiovascular Atrioventicular canal...s http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.CDV.10.AllAg.Atrioventicular_canals.bed ...

  16. File list: His.CDV.10.AllAg.Atrioventicular_canals [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.CDV.10.AllAg.Atrioventicular_canals mm9 Histone Cardiovascular Atrioventicular canal...s http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.CDV.10.AllAg.Atrioventicular_canals.bed ...

  17. File list: Unc.CDV.20.AllAg.Atrioventicular_canals [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.CDV.20.AllAg.Atrioventicular_canals mm9 Unclassified Cardiovascular Atrioventicular canal...s http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.CDV.20.AllAg.Atrioventicular_canals.bed ...

  18. File list: His.CDV.20.AllAg.Atrioventicular_canals [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.CDV.20.AllAg.Atrioventicular_canals mm9 Histone Cardiovascular Atrioventicular canal...s http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.CDV.20.AllAg.Atrioventicular_canals.bed ...

  19. [Dependence of the dentinal abrasion of human teeth on their microhardness].

    Science.gov (United States)

    Remizov, S M; Pruzhanskiĭ, L Iu

    1989-01-01

    The dentin resistance against abrasion was studied as related to its microhardness. Sections of 15 intact teeth were investigated (central upper incisors). Water suspensions (40% weight-to weight) of dicalcium phosphate (DCP, FRG; and DKF-1 and DKF-2, USSR) were used as abrasives. Dentin microhardness was measured with a PMT-3 device, and abrasion assessed with profilographic technique. Dentin abrasion was related to its microhardness and to the kind of abrasive used. Dentin abrasion increased as its microhardness decreased. DCF showed minimal abrasive effect, DKF-2 had maximal effect with DKF-1 keeping the intermediate position.

  20. Application of laser therapy for the treatment of dentinal hyperesthesia

    International Nuclear Information System (INIS)

    An experimental study was carried out, to evaluate the effectiveness of the low - power laser combined with fluoride varnish to 2% (Profilac) in the treatment of the Dentinal Hyperesthesia in patients attended to in the Stomatology Clinic of Ciro Redondo in the period from October 2007 to January 2008. The universe of study was constituted by 75 patients diagnosed with dentinal hyperesthesia in the period of time indicated above, being conformed the sample by those 25 who fulfilled the pre-established criteria for the study. With the application of the laser combined with Lacquer Fluorine (Profilac), a remission of the pain was observed that increased gradually with the treatment sessions, having been obtained to almost eliminate in the totality of the cases the group of symptoms when finalizing it, evaluating the treatment of effective in 100% of the cases. We only found a recidivism after a year of treatment