Knowledge, Attitude, and Perception Among Endodontists Toward Regenerative Endodontics: A Cross-sectional Survey of Four Indian Universities.

BACKGROUND: Regenerative endodontics is a rapidly developing field in dentistry. However, the regenerative endodontic procedures are not familiar to many clinicians in India. AIM: This survey aimed at assessing the level of knowledge, attitude, and perception (KAP) among endodontists toward regenerative endodontics. MATERIALS AND METHODS: A cross-sectional survey was conducted in the year 2019 to collect data. A questionnaire to collect data on KAP toward regenerative endodontics was administered to 49 faculty and 69 postgraduate students of endodontics from four universities. The Chi-Square test and logistic regression were applied to study the association between KAP and demographic variables. Spearman's rho was computed to study the correlation between KAP scale scores of the participants. The data were analyzed by using Statistical Package for the Social Sciences software program (SPSS), version 15.0 (South Asia, Bangalore). RESULTS: The survey yielded an overall response rate of 81%. Less than 50% of the participants had sound knowledge, 65% had a positive attitude, and only 21% had a positive perception about Regenerative Endodontic Procedures (REPs). Most of the participants (86.5%) were of the opinion that regenerative therapies should be a part of dentistry. Majority of the participants (89.6%) were inclined to receive training in REPs. About 80% of the participants felt that the higher cost of treatment is a significant hurdle for patients to accept REPs. Less than half the participants (41.7%) were using REPs in their clinical practice, such as the use of membranes, scaffolds, and revascularization. CONCLUSION: Endodontists have a positive attitude toward the use of regenerative therapies. However, there is a deficiency of training in REPs in dental colleges.

Efficient removal of 2,6-xylidine precipitate using different agitation protocols: An in vitro field emission scanning electron microscopic study.

Background: Any solution of chemical nature when combined will result in the formation of a precipitate, which in the root canal system will interfere with the hermetic seal. In clinical practice presence of any precipitate, especially carcinogenic in nature, should be eliminated. Aim: To evaluate whether final irrigation with different agitation protocols will remove the precipitate formed following lidocaine hydrochloride and sodium hypochlorite combination at the coronal, middle, and apical-root thirds. Materials and Methods: Forty-four uniradicular teeth were standardized at 17 mm. All specimens were injected with 2% lidocaine hydrochloride and 2.5% sodium hypochlorite, followed by mechanical instrumentation using rotary files. Further, specimens were arbitrarily divided into four groups (n = 11) based on the final irrigation protocol: Group 1: No irrigation; Group 2: Manual irrigation; Group 3: Mechanical irrigation; Group 4: Ultrasonic irrigation. Samples were sectioned and Field Field Emission Scanning Electron Microscopic (FESEM) analysis of the canal wall was done at coronal, middle, and apical thirds. Results: FESEM images revealed occluded dentinal tubules with the presence of precipitate seen in all-thirds of each specimen. Conclusion: No irrigation protocol was successful in removing the precipitate formed; but when compared ultrasonic irrigation had the least precipitate seen at-coronal,-middle and apical thirds.

An in vitro evaluation of dentinal tubule occlusion using three desensitizing methods: A scanning electron microscopic study.

AIM: The aim is to compare the effects of diode laser, GC tooth mousse, and sodium fluoride (NaF) varnish on dentinal hypersensitivity by scanning electron microscopic (SEM) evaluation. MATERIALS AND METHODS: Forty extracted human maxillary first premolar teeth were selected to prepare dentin disc of 2 mm thickness. The specimens were divided into four groups of 10 discs each-Group 1: Negative control, Group 2: Diode laser, Group 3: GC tooth mousse, and Group 4: NaF varnish. Diode laser and NaF was exposed on dentin disc for three consecutive days. GC tooth mousse was applied twice a day for 1 week. All the specimens were examined under SEM at a magnification of ×1500. The standardized SEM microphotographs were analyzed according to the scoring criteria. STATISTICAL ANALYSIS: Friedman test with post hoc Wilcoxon sign rank test for pair wise comparison at different time intervals within the group was computed using SPSS version 20. A P < 0.05 was regarded as statistically significant. RESULTS: The results showed that the use of diode laser was able to achieve complete occlusion of dentinal tubules followed by the use of GC tooth mousse and that of NaF varnish while control group showed completely open tubules. CONCLUSIONS: Irradiation of dentinal tubules using diode laser could be effective for routine clinical treatment of dentinal hypersensitivity compared to NaF and GC tooth mousse.

Fracture Resistance of Endodontically Treated Maxillary Premolars with a Longer Single Post and Shorter Double Posts of Different Sizes: An In Vitro Study.

AIM: The aim of this study was to determine if there is any difference in fracture resistance between different post sizes and lengths when more than one post is involved. MATERIALS AND METHODS: Thirty extracted maxillary first premolars were endodontically treated and divided into three groups: In Group 1 (control group), no post space preparation was conducted and access cavities were restored with composite; in Group 2 (single post), post space preparation of 10 mm was carried out only in one of the canals; and in Group 3 (double post), post space preparation of 5 mm was conducted in both the canals. Appropriately sized glass fiber posts were cemented in Groups 2 and 3 followed by core buildup. The fracture resistance of the specimen was measured using a universal testing machine and the data analyzed. The mean fracture resistance values of the three groups were compared applying one-way analysis of variance (ANOVA) followed by post hoc Tukey's test. The data were analyzed using Statistical Package for the Social Sciences software program, version 15.0. South Asia, Bangalore. RESULTS: The control group had a significantly lower fracture resistance value as compared to Groups 2 and 3. No statistically significant difference was observed in the fracture resistance between Groups 2 and 3. CONCLUSIONS: No significant difference was observed between the fracture resistance of endodontically treated maxillary first premolars restored with size 3 single post of longer length and size 1 double posts of shorter lengths.

Finite element analysis of immature teeth filled with MTA, Biodentine and Bioaggregate.

BACKGROUND AND OBJECTIVE: Finite element based simulation has emerged as a powerful tool to analyse the tooth strength and its fracture characteristics. The aim of this study is to compare and evaluate the fracture resistance of immature teeth reinforcement with MTA, Biodentine and Bioaggregate as an apical plug and backfill material using Finite Element Method. METHODS: A 3D finite element analysis model was generated using a simulated immature maxillary central incisor. Seven different models were developed representing (Model 1): control group having an immature tooth model without any reinforcement material; (Model 2): Mineral trioxide aggregate (MTA) as apical plug 4 mm; (Model 3): Biodentine as apical plug 4 mm; (Model 4): Bioaggregate as apical plug 4 mm; (Model 5): MTA filled in the entire root canal 8.5 mm; (Model 6): Biodentine filled in the entire root canal 8.5 mm; (Model 7): Bioaggregate filled in the entire root canal 8.5 mm. A force of 100 N was applied at an angle of 130° to the palatal surface of the tooth. Stress distribution at cemento­enamel junction was measured using the Von Mises stress criteria. RESULTS: It was found that the 4 mm apical plug using MTA showed higher fracture resistance when compared to 8.5 mm backfill using MTA. When MTA was replaced as backfill material by Biodentine and Bioaggregate, the von mises stress increased by 64% and 94% respectively. CONCLUSIONS: It is not desirable to restore the entire root canal of an immature teeth using same material due to higher stress concentration at the cervical region. Considering the shorter setting time and improved handling characteristics, Biodentine can be preferred over the time­tested MTA as an apical plug.

Evaluating the Effect of Different Conditioning Agents on the Shear Bond Strength of Resin-Modified Glass Ionomers.

AIM OF THE STUDY: This study aims to evaluate the effects three different conditioning agents on the shear bond strength of resin-modified glass ionomers to human dentin. MATERIALS AND METHODS: One hundred and twenty recently extracted, caries-free premolars and molars will be cleaned of debris and disinfected in a 0.5% solution of sodium hypochlorite and sterile water for 30 min. The occlusal surface of each tooth will be reduced using conventional model trimmer with water to produce the dentin surface. Then, three different resin-modified glass ionomer cements (GICs) were triturated and mixed according to the manufacturer's instructions, 10 specimens will be made of each group. The excess restorative material will be removed from matrix band dentin interface with a sharp number 25 bard parker blade. Samples were shear tested with Instron universal testing machine with a crosshead speed of 0.5 mm/min. A shearing bar beveled to a 1 mm thick contact surface area will be placed at the junction of dentin and plastic band matrix. The load required for the failure will be recorded in pounds and converted to megapascals. RESULTS: Statistical analysis was done with analysis of variance and Tukey's test. Ketac primer as conditioning agent along with Fuji II LC as restorative material had the highest shear bond value whereas intact smear layer which was unmodified dentin had the least value. CONCLUSION: Within the limitations of the present study, it can be concluded that surface conditioning of dentin resulted significantly higher bond strength than unconditioned dentin surfaces. CLINICAL SIGNIFICANCE: Resin-modified glass ionomers have several advantages compared to chemically cured GICs. The advantages include command cure, ease of handling, improved physical properties, and esthetics. Resin.modified glass ionomers have been marketed as direct restorative materials for Class V lesions as well as liners, bases, and luting agents. Several conditioning agents have been evaluated to condition dentin before the application of conventional glass ionomers and resin-modified glass ionomers. These have mainly included polyacrylic acid, citric acid, phosphoric acid, and ethylenediamine tetra.acetic acid. Of late, manufactures have recommended other conditioners to replace polyacrylic acid which includes Ketac primer as one of the conditioning agents.

Shear Bond Strength of Superficial, Intermediate and Deep Dentin In Vitro with Recent Generation Self-etching Primers and Single Nano Composite Resin.

BACKGROUND: This in vitro study is intended to compare the shear bond strength of recent self-etching primers to superficial, intermediate, and deep dentin levels. MATERIALS AND METHODS: All teeth were sectioned at various levels and grouped randomly into two experimental groups and two control groups having three subgroups. The experimental groups consisted of two different dentin bonding system. The positive control group consisted of All Bond 2 and the negative control group was without the bonding agent. Finally, the specimens were subjected to shear bond strength study under Instron machine. The maximum shear bond strengths were noted at the time of fracture. The results were statistically analyzed. RESULTS: Comparing the shear bond strength values, All Bond 2 (Group III) demonstrated fairly higher bond strength values at different levels of dentin. Generally comparing All Bond 2 with the other two experimental groups revealed highly significant statistical results. CONCLUSION: In the present investigation with the fourth generation, higher mean shear bond strength values were recorded compared with the self-etching primers. When intermediate dentin shear bond strength was compared with deep dentin shear bond strength statistically significant results were found with Clearfil Liner Bond 2V, All Bond 2 and the negative control. There was a statistically significant difference in shear bond strength values both with self-etching primers and control groups (fourth generation bonding system and without bonding system) at superficial, intermediate, and deep dentin. There was a significant fall in bond strength values as one reaches deeper levels of dentin from superficial to intermediate to deep.