COMPARISON OF FOUR DIFFERENT ENDODONTIC ROTARY SYSTEMS IN TERMS OF CYCLIC FATIGUE

Objectives: The aim of this study was to compare four endodontic rotary systems in terms of cyclic fatigue. Material and Methods: 25/.08 Twisted File (TF), TF Adaptive, Reciproc and WaveOne rotary files were used to test the cyclic fatigue strength in this study. Four different artificial canals, compatible with the file size and taper, were created, with the curvature angle and radius of 450-2 mm, 600-2 mm, 450-5 mm and 600-5 mm, respectively. The front surface of the artificial canals was covered with a removable glass plate. The files were operated in the canals according to their own working principles until they fractured. The fracture time was determined by using a chronometer with 1/100 second accuracy and the cyclic fatigue strength was evaluated according to the time until fracture occurs. A total of 40 files, 10 in each canal, were used in each group. SPSS program was used for statistical analysis. Mann-Whitney U test was applied for pairwise comparisons. Bonferroni correction was applied and P<0.008 was considered as statistically significant. Results: In all canals, fracture time was the highest for Reciproc files, followed by WaveOne, TF Adaptive and TF files, respectively. For the canal curvature of 450-2 mm, the Reciproc files were significantly more resistant to fracture than the others. While there was no significant difference between TF Adaptive and TF, WaveOne was significantly more resistant than both groups. In canals with the curvature of 600-2 mm and 450-5 mm Reciproc and WaveOne were significantly more resistant to fracture than TF Adaptive and TF. In addition, TF Adaptive was significantly more resistant than TF. For the curvature of 600-5 mm, the difference between all groups was significant. Conclusions: Regardless of the canal curvature, the Reciproc exhibited the highest cyclic fatigue strength, while the TF showed the lowest fatigue strength

The comparison of cleaning efficacy and apical extrusion of advanced irrigation activation methods with a novel Er:YAG laser modality: sweeps

Purpose: Laser-activated irrigation (LAI) is an activation method that is based on transferring pulsed energy to the irrigation solution by using different fiber tips and generating explosive vapor bubbles with a secondary cavitation effect, causing rapid solution movement through the root canal. This study aimed to compare different types of LAI and ultrasonically activated irrigation (UAI) in terms of cleaning efficacy by using scanning electron microscopy (SEM) images. Methods: Sixty straight and single-rooted mature mandibular premolars were prepared with ProTaper Ni-Ti rotary instruments up to F4. According to the final irrigation/agitation protocols, four experimental groups (n = 15) were generated as conventional laser–activated irrigation (group 1: C.LAI), photon-induced photoacoustic streaming (group 2: PIPS), shock wave–enhanced emission photoacoustic streaming (group 3: SWEEPS), and passive ultrasonic irrigation (group 4:UAI). The irrigation protocols were performed for 60 s with 2.5% NaOCl and 17% EDTA. Debridement was evaluated using SEM with a scoring system. Apical extrusion was calculated using cube-shaped flower arrangement foam by subtracting the initial weights from the final weights. All data were statistically analyzed. Results: C.LAI and SWEEPS showed significantly lower debris scores than PIPS and UAI (p < 0.001). However, there was no significant difference between C.LAI and SWEEPS. In the PIPS group, significantly more debris residue was found compared with the other groups. Apical extrusion was significantly lower in the PUI groups than in the laser-activated groups (C.LAI, PIPS, SWEEPS). There was no significant difference between laser-activated groups. Conclusions: It can be concluded that the use of the C. LAI and novel laser-activated irrigation modality (SWEEPS) provides greater cleaning efficacy compared to UAI and PIPS. Besides, the observed results should not be generalized to teeth with shorter or longer root length and smaller or larger canal preparation with immature root development and open apices. In teeth with resorption, perforation defects or immature roots with open apex, the higher amount of apical extrusion should also be taken into account

Evaluation of endodontically treated teeth and related apical periodontitis using periapical and endodontic status scale: Retrospective cone-beam computed tomography study

The purpose of this study was to evaluate the technical treatment quality and the status of apical pathology of endodontically treated teeth, as well as apical periodontitis (AP) prevalence, in a Turkish population using cone-beam computed tomography (CBCT). The CBCT images obtained between January 2018 and April 2020 were retrospectively examined. The quality of the endodontic treatments and the related periapical inflammatory lesions were classified according to the periapical and endodontic status scale (PESS). The data were statistically analysed using logistic regression, crosstabs and chi-square tests. AP was detected in 41% of 429 endodontically treated teeth. The prevalence of AP was significantly higher in teeth with inadequate root canal treatment compared with those with adequate treatment, 70.8% and 29.3%, respectively. Inadequate canal length and homogeneity, and complications were significantly associated with the prognostic periapical status scores of higher risk

Assessment of bone quality of apical periodontitis treated with MTA plug and regenerative endodontic techniques

Fractal analysis (FA) is a quantitative, objective and non-invasive method that facilitates the characterisation of the tissue architecture. This study aims to compare the periapical healing at 1-year follow-up by evaluating newly generated trabecular bone with FA after Mineral trioxide aggregate (MTA) plug and regenerative endodontic treatment (RET). A total of 55 asymptomatic teeth with a single-canal, open apex and periapical lesion, treated with MTA plug or RET, were evaluated retrospectively. After considering the inclusion/exclusion criteria, FA was conducted on 30 periapical images using the box-counting method. In both groups, a significant decrease was observed in the periapical lesion size at 1-year follow-up (p 0.01). Significantly higher fractal dimension values were detected at 1-year follow-up in both MTA plug and RET cases (p 0.01). Both procedures seem to improve periapical healing with a new resistant bone of similar density and complexity