Evaluation of calcium hydroxide removal efficiency of different irrigation techniques by microleakage assessment using Computerized Liquid Filtration method

Aim: To compare the efficiency of sonic irrigation, passive ultrasonic irrigation, and conventional syringe irrigation (CI) in removing pure and injectable calcium hydroxide (CH) from the root canals of mandibular second premolars by measuring the probable microleakage of residual CH particles in root canal obturation using computerized liquid filtration (CLF). Materials and Methods: Eighty instrumented mandibular second premolars were categorized into three experimental groups (n = 20 each) based on the irrigation method used for removing CH and a control group (n = 20) in which CH was not used. Each experimental group was divided into two equal groups (pure and injectable CH). After 1 week, CH was removed from the root canals, and the teeth were obturated. CLF measurements were performed 1 week after obturation. Nonparametric variables between two groups were compared using the Mann-Whitney U test, and the Kruskal-Wallis test was used to compare more than two groups. The significance level was set at p < 0.05. Results: All experimental groups showed higher leakage values than the control group. The highest leakage values were evident in the CI group, and the lowest leakage values were found in the sonic (EDDY) irrigation group. No significant differences were detected among the different forms of CH. Conclusions: None of the analyzed techniques could completely remove CH from root canals, resulting in higher leakage values. Sonic irrigation with EDDY was the best in removing CH from root canals

Evaluating the Effect of Different Laser Types on Dentin Fracture Resistance

Objectives: The aim of this in-vitro study was to evaluate the impact of the use of different laser types--particularly diode, Nd:YAG and Er:YAG--on dentin fracture resistance, with the assistance of fracture testing methods. Materials and Methods: Ninety human maxillary incisors were used. The teeth were divided into three experimental groups and three control groups, each of which included 15 samples. Group 1 had diode, group 2 had Nd:YAG, and group 3 had Er:YAG laser performed on them, after which they were dried and obturated using AH-Plus sealer and RevoS AS40 Gutta Percha (GP). Control group 1 was obturated just as in the experimental groups but without laser application; 2) control group was instrumented but not obturated; and 3) negative control group had no procedure performed at all. All the samples were fixed in acrylic blocks and had fracture tests performed on them using an Autograph Universal Testing Machine. The results were analyzed using IBM SPSS Statistics 22 software, the one-way ANOVA test and Tukey HDS (group identified that causes a difference) with significance