Search

Background : Fracture resistance is a mechanical property that describes the resistance of brittle materials to the catastrophic propagation of flaws under an applied load. Therefore any material that can compensate for this weakening effect could be useful. Thus to reinforce the instrumented teeth against fracture; sealers are used in conjugation with a core filling material. Material and Methods: One hundred and twenty extracted caries-free and visually assessed fracture-free, human single rooted mandibular premolar teeth were selected for the study. The prepared teeth were randomly divided into four experimental groups and two control group of 20 teeth each. One control group of 20 teeth where access opened and left unistrumented and unobturated.Group- I: Teeth obturated with gutta percha and epoxy resin based sealer;Group- II: Teeth obturated with polymer based core and methacrylate based Sealer;Group- III: Teeth obturated with gutta percha and calcium silicate based sealer. ;Group IV: Teeth obturated with gutta percha and zinc oxide eugenol based sealer.;Group V: Teeth instrumented and obturated with gutta percha without use of sealer (Positive control).;Group VI – Teeth with no instrumentation or obturation (Negative control).

Introduction: This study compared the amount of canal transportation, canal centering ability after instrumentation and time required for shaping of canal with WaveOne Primary Reciprocating file and OneShape Rotary file. Method: Thirty intact mesial roots of mandibular first molars were divided into Group I and Group II. Specimens in Group I were shaped with WaveOne Primary reciprocating files to the working length (WL) and specimens in Group II were shaped with OneShape Rotary file to the WL. Time required to prepare each canal was recorded. All the specimens were submitted to micro-computed tomography (µCT) unit for Pre- and post-instrumentation scan. Images were reconstructed and cross-sections corresponding to distances 3, 6 and 9 mm from the anatomic apex were selected for analysis. Statistical analysis was performed with Kruskal Wallis and paired t test. Results: Overall, both rotary files maintained root canal curvatures well. During canal preparation, OneShape file performed significantly better in the apical third when compared to the WaveOne Reciprocating file. WaveOne file required reasonably less time to prepare canal when rather than OneShape file.

Aim The aim of this in vitro study was to estimate the penetration depth and fracture resistance of three different sealers and to verify the relationship between the penetration depth and fracture resistance. Materials and methods Sixty single-rooted teeth were selected and root canal preparation was done. After the instrumentation, the teeth were divided into three groups of 20 each. The groups were then obturated with gutta-percha (GP)-AH Plus sealer, Resilon-Real Seal, and propoint-bioceramic sealers, respectively. Ten teeth from each group were sectioned at three different regions (i.e., coronal, middle, and apical thirds of the root canal) and were viewed under a confocal microscope to determine the penetration depth of the sealer. The remaining samples were subjected to fracture resistance under a universal testing machine and the statistical analysis was done by using one-way ANOVA and post hoc Bonferroni tests. Results Propoint-bioceramic group showed the highest fracture resistance values followed by GP-AH Plus sealer and Resilon-Real seal groups with no significant difference noticed between them. Depth of penetration was greater for GP-AH Plus sealer, propoint-bioceramic, with no significant difference followed by the Resilon-Real seal group. Conclusion The newer obturating material propoint-bioceramic group showed a greater fracture resistance. No correlation could be established between the depth of sealer penetration and fracture resistance. Clinical significance Fracture resistance of tooth obturated with propoint-bioceramic sealer combination is significantly greater than GP-AH Plus and Resilon-Real seal combination, thereby showing propoint-bioceramic as a promising obturating material.

Introduction: The aim of this study was to compare calcium (Ca) ion-releasing capacity of four different light-cured calcium hydroxide [Ca(OH) 2 ] cements with self-cured Ca(OH) 2 cement. Materials and Methods: Five different brands of Ca(OH) 2 cements were taken and they were grouped into five groups which are as follows: Group I - Dycal (control group), Group II - Septocal, Group III – TheraCal, Group IV - Cal LC, and Group V - Hydrocal. All specimens ( n = 50) were prepared by mixing and curing the cements as per manufacturer's instructions. Each sample was placed on the bottom of a 4 cm high test tube in 10 ml deionized water at 37°C. This stored water was collected for Ca analysis and replaced after 7, 14, and 21 days. In this manner, ion release was measured after 7, 14, and 21 days by inductively coupled plasma-optical emission spectroscopy test. Results: Ca ion release from all groups at various time durations was measured and mean was calculated along with the standard deviation. These values were compared using two-way ANOVA and Tukey's post hoc test which showed highly significant result with P Conclusions: Within the limitations of this study, light-cured Ca(OH) 2 cements released high amount of Ca ions compared to self-cured Ca(OH) 2 cements. Group V (Hydrocal) and Group III (TheraCal) were found to be the highest light-cured Ca ion releasing materials.