Assessment of different irrigation techniques on the penetration depth of different sealers into dentinal tubules by confocal laser scanning microscope: An in vitro comparative study.

Background: The effective disinfection of the entire root canal system aids in the penetration of irrigants into the dentinal tubules further improving sealer penetration and achieving a three-dimensional seal in endodontically treated teeth. Various final irrigation techniques can be employed to achieve this goal. Therefore, this study intended to assess and compare the efficacy of three final irrigation techniques on the depth of penetration of two root canal sealers into dentinal tubules using confocal laser scanning microscope (CLSM). Methods: Forty-eight single-rooted mandibular premolars were selected and decoronated to a length of 12 mm. All the samples were prepared using ProTaper Gold rotary files and divided into three groups: Group 1 - Conventional syringe irrigation (CSI), Group 2 - passive ultrasonic irrigation (PUI), and Group 3 - Pro-agitator tip system (PATS). Each group was divided into two subgroups: Subgroup A - AH Plus and Subgroup B - GuttaFlow Bioseal (GFB). Then, sealers were mixed with 0.1% rhodamine B dye and the samples were obturated. All the samples were sectioned at 2 mm and 5 mm from the apex and visualized under confocal laser scanning microscope (CLSM) (10×) for maximum mean penetration depth and percentage of sealer penetration. Statistical analysis was done using the independent t-test and one-way analysis of variance test, followed by Tukey's Post hoc analysis. Results: PUI performed better in the apical third, whereas PUI and PATS showed comparable results in the middle third for both depth and percentage of sealer penetration. Among the two sealers, GFB performed better than AH Plus in both the apical and middle third. These values were statistically significant. (P < 0.05). Conclusion: Final irrigation activation with PUI or PATS can significantly improve sealer penetration. The average depth of penetration of GFB both at the middle and apical third of the root was significantly superior to AH Plus.

An in vitro assessment of cytotoxicity and genotoxicity of root repair materials.

Background: The success of the root-end procedure depends on the regeneration of the functional periodontal attachment system, including the cementum on the resected root-end surface, periodontal ligament (PDL), and alveolar bone. As root end filling materials remain in close contact with live periapical tissues, they may influence the endodontic treatment outcome. Aim: To assess and compare the cytotoxicity and genotoxicity of three root repair materials, mineral trioxide aggregate (MTA), endosequence, and geristore in human-cultured periodontal ligament fibroblasts. Materials and Methods: Cultured human periodontal ligament fibroblasts of the third passage were used in the study. They were placed in contact with the root repair materials. The cytotoxic effect on PDL fibroblasts was determined by (3-(4,5-dimethylthiazol-2-yl)-2,5-tetrazolium bromide) assay after 24 hours and 48 hours intervals. Cell viability was determined using an inverted phase contrast microscope. The genotoxic effect on the periodontal fibroblast cells was determined by comet assay using imaging software. Statistical Analysis Used: Data were analyzed using Tukey's multiple comparison test and Dunnett's multiple test. Results: All the test materials showed higher cytotoxicity and genotoxicity at the 48th hour interval with a statistically significant difference from the control group (P < 0.05). MTA was shown to be least cytotoxic and genotoxic to PDL fibroblasts, followed by endosequence root repair material and geristore at 24 hour and 48 hour intervals. Conclusion: The cytotoxicity and genotoxicity of MTA were the least compared to endosequence and geristore on human-cultured PDL fibroblasts.

Effect of pulpal floor perforation repair on biomechanical response of mandibular molar: A finite element analysis.

Background: Evaluation of the biomechanical response of tooth with perforation repair is important to attain predictable prognosis. It may remain altered even after perforation repair due to the loss of tooth structure. Aim: The aim of this study is to assess and compare the effect of pulpal floor perforation repair of different sites with biodentine, on the biomechanical response of mandibular molar through 3-dimensional (3D) finite element analysis (FEA). Materials and Methods: Five different 3D models were constructed based on the site of perforation on the pulpal floor using cone-beam computed tomographic images of an extracted mandibular molar. Perforation size was standardized and simulated to be repaired with calcium silicate-based cement. A force of 200 N was applied simulating normal occlusal loads. Static linear FEA was performed using the Ansys FEA software. Tensile stresses were evaluated (Pmax). Statistical Analysis Used: The data were evaluated using the independent t-test (P = 0.05). Results: All the simulated models with perforation repair exhibited higher stress values than their equivalent sites in the control group. The Pmax values of the repaired models were highest in central furcal perforation, followed by buccal furcal perforation. However, there was no statistically significant difference in the stress accumulation among the different repaired perforation sites. Conclusion: The site of the pulpal floor perforation affected the stress distribution and accumulation. Central and buccal furcal perforation repairs on the pulpal floor with calcium silicate-based cement in mandibular molar are likely to have an increased risk of fracture.

Effect of final irrigating solutions on penetration depth of resin-based sealers into dentinal tubules.

Background: The goal of root canal therapy depends on chemomechanical debridement and three-dimensional filling of the root canal system.[1]. Aim: The aim of this study is to assess the effect of NaOCl + Ethylenediaminetetraacetic acid (EDTA) and Twin Kleen as a final irrigating solution on the depth of penetration of AH Plus and Perma Evolution sealers into the dentinal tubules. Materials and Methods: Forty mandibular premolars were decoronated and instrumented up to size 30. Moreover, randomly assigned into two groups based on final rinse Group A (n = 20): 5.25% NaOCl + 17% EDTA. Group B (n = 20): Twin Kleen solution. Resin sealers were labeled with few grains of fluorescent rhodamine B dye and subdivided into two subgroups, Subgroup A1and B1 (n 1= 10): AH Plus; Subgroup A2 and B2 (n 2= 10): Perma Evolution and obturated. Confocal laser scanning microscopy was used to examine the sections taken 2, 5, and 8 mm from the apex. Images were exported to Image J software to determine the sealer penetration depth. Statistical Analysis: Independent t-test and one-way analysis of variance followed by Tukey's HSD post hoc test. Results: Maximum depth of sealer penetration was seen in Twin Kleen in all sections. Perma Evolution showed highest sealer penetration at the middle and apical third region of root canal for both groups. Conclusions: Final irrigation with Twin Kleen produced highest sealer penetration than with EDTA.

Biological posts and crown: An esthetic recovery of smile.

Anterior teeth fracture is a common form of dental trauma that mainly affects children and adolescents. Maxillary incisors are the most commonly affected teeth. Loss of coronal tooth structure might affect esthetics and function. In recent decades, dentistry has shown many scientific and technological advances in restorative materials. However, no synthetic restorative material can replicate the natural tooth structure. Hence, the use of natural tooth as a restorative material has been suggested in literature and is termed as a biological restoration. The present case report represents the successful use of biological post and crown and was adequate with respect to adhesion, function, and esthetics with the follow-up period of 1 year. Hence, it may be concluded that the biological restoration, if feasible, is a cost-effective way to restore a damaged tooth with acceptable esthetics and tooth functions in the stomatognathic system.

Influence of ultrasound, with and without water spray cooling, on removal of posts cemented with resin or glass ionomer cements: An in-vitro study.

AIMS/OBJECTIVES: To evaluate in vitro the ultrasonic vibration efficacy with and without water spray cooling on the reduction of the amount of force necessary to dislodge the cast posts cemented with resin cement and to compare it with those cemented with GIC Type I luting cement. MATERIALS AND METHODS: SIXTY SAMPLES WERE DIVIDED INTO SIX GROUPS: groups 1, 2, 3, posts cemented with GIC; groups 4, 5, 6, posts cemented with resin; groups 1 and 4 (controls), no ultrasound; groups 2 and 5, ultrasound without water spray; and groups 3 and 6, ultrasound with water spray. Instron testing machine was used to dislodge the posts from the root canals and the data was statistically analyzed. RESULTS: Ultrasound with water spray (group 3) among the GIC groups reduced the traction force necessary to extract posts by 53.33% whereas ultrasound without water spray (group 5) among the resin groups reduced by 59.5% compared to control. CONCLUSION: Ultrasound with water is more effective in removing posts cemented with GIC because of the ultrasonic energy being transferred to the post. Ultasonics without water is more effective in removing posts fixed with resin cement probably by the indirect action of heat production.