ABSTRACT
Background: Various instrument kinematics used in single-visit endodontics influence the occurrence of pain after endodontic therapy. This study aimed to evaluate the occurrence of pain after mechanical instrumentation with Hyflex EDM (HEDM) and WaveOne Gold (WOG) during single-visit endodontic therapy. Methods: Sixty patients diagnosed with asymptomatic irreversible pulpitis and normal apical tissues in mandibular premolar teeth were included in the study for single-visit root canal therapy. The patients were divided into two groups (n = 30) according to the rotary instrument used during root canal preparation (group A [HEDM] and group B [WOG]). Pain was evaluated after endodontic therapy at 8, 24, and 48 h intervals using the visual analog scale (VAS). Data obtained were analyzed using the chi-square test, independent t-test, MannWhitney U test, and Wilcoxon matched-pairs test. Results: Statistically significant differences were observed between the two groups (P < 0.001) at 8, 24, and 48 h, with WOG exhibiting less pain than HEDM files. Conclusion: Postoperative pain was lower in the WOG file system than in the HEDM file system after single-visit root canal therapy at 8, 24, and 48 h.
ABSTRACT
Background: Tooth whitening procedures such as bleaching and microabrasion alters the enamel surface and thus reduce the composites' bond strength. Hence, various surface treatments were introduced to overcome this problem. Aim: To assess the effect of nonthermal atmospheric plasma (NTAP), grape seed extract (GSE) and bromelain on the shear bond strength (SBS) of the composite after bleaching and microabrasion. Materials and Methods: Eighty extracted maxillary anterior teeth were distributed into two groups. Group 1: bleaching and Group 2: Microabrasion and further subdivided into four subgroups (n = 10) based on the form of surface treatment employed. Group A: no surface treatment, Group B: bromelain, Group C: GSE, Group D: NTAP. Composite resin was bonded to the labial surface and placed in artificial saliva for 24 h. SBS testing was done for all the samples. Statistical Analysis: Analysis was performed using two-way analysis of variance and post hoc Tukey's test with P < 0.05 considered statistically significant. Results: Group 1D revealed the highest bond strength (35.4 Mpa) and Group 1A showed the least bond strength values (15.7 Mpa). Among the bleaching groups, significant difference was observed between all the subgroups except Group 1A and 1B (P = 0.972). In microabrasion group, significant difference was observed between Group 2A and 2D (P = 0.0001), Group 2B and 2D (P = 0.0010), and Group 2C and 2D (P = 0.0001). Conclusions: Following bleaching, NTAP application and GSE significantly improved the SBS of composite resin. Application of NTAP to microabraded surfaces increased the bond strength of composite resin.
ABSTRACT
Aim: The aim of the study is to determine the effect of autoclaving on the cyclic fatigue resistance (CFR) in respect to three different rotary nickel-titanium (NiTi) systems. Methods: Three rotary NiTi files with different manufacturing process were selected and arranged into three groups. Group 1: Neolix Neoniti files (n = 15), Group 2: Edge Files (n = 15), Group 3: NeoendoFlex files (n = 15). Each group was then subdivided into three subgroups containing 5 samples each based on the number of cycles of autoclaving (0, 1, 5 cycles). The instruments were subjected to autoclave without usage. The files of size 25, taper 6%, and 25 mm length were taken. After the autoclaving cycles, the files were rotated in cyclic fatigue testing device with simulated canal curvature of 60° until file separation. Time taken for the instrument separation (in minutes) was multiplied by the number of rotations per minute to attain the mean number of cycles to failure for every file. The obtained results were subjected to statistical analysis using two-way ANOVA and Newman-Keuls multiple post hoc procedures. Results: Neolix Neoniti files exhibited the maximum CFR (98.80) than EdgeFiles (80.47) and Neoendo Flex files (41.80) (P = 0.0001). Reduction in CFR was observed with increase in the number of cycles of autoclaving (i.e., 0, 1, 5 cycles). Conclusion: Autoclaving has a negative influence on the CFR of the rotary NiTi files used. Neolix Neoniti files exhibited greater CFR than EdgeFiles and Neoendo Flex files.
ABSTRACT
Ideal coronal restoration that provides satisfactory esthetic and functional outcome for endodontically treated and extensively damaged teeth is still an arduous task for restorative dentistry. None of the available post systems have all the ideal biological and mechanical properties. Biological dentin posts are considered as a good alternative to conventional post systems as they preserve dentin walls, which results in better distribution of forces along the root surfaces in the compromised tooth. This case report is an attempt to detail "autogenous dentin post" which serves as a homologous unit for the reinforcement of endodontically treated tooth by virtue of its biomimetic property.
ABSTRACT
AIM OF THE STUDY: We aimed to compare stress distribution in a tooth restored with fiber post and dentin post after applying the orthotropic properties using three-dimensional finite element analysis (3D-FEA). MATERIALS AND METHODS: Two 3D-FEA models were constructed. The material properties were assigned, and a load of 100 N was applied at 45° to the long axis of the model onto the lingual surface incisal to the cingulum. The FEA was done by applying orthotropic properties of dentin and fiber post. The maximum stresses produced in the tooth and post referred to as von Mises stress were recorded. The Ansys software was used which depicts the stress concentrations. RESULTS: Von Mises values showed that glass fiber post (331 MPa) and dentin post (338 MPa)-restored tooth models presented similar stress values. CONCLUSION: Although both fiber post and dentin post presented similar von Mises stress values, the pattern of stress distribution is more favorable in dentin post. More favorable fracture could be expected in case of dentin post. Thus, the dentin post is a promising alternative post material for rehabilitating endodontically treated teeth. CLINICAL SIGNIFICANCE: Ascribing the orthotropic properties in a FEA study means that the computational simulation was similar to that of clinical scenario, and hence simulates the dynamic intraoral conditions, thereby giving the accurate results.
