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Objective:To evaluate the effects of various endodontic regeneration agents on the push-out bond strength of Endosequence Root Repair Material (ERRM) to root-canal dentin.Methods:Fifty single-rooted human teeth were selected and instrumented to obtain a standard internal diameter of 1.5 mm. Specimens were randomly divided into four experimental groups and treated with an intracanal medicament [calcium hydroxide (CH), double antibiotic paste (DAP), triple antibiotic paste (TAP), TAP with amoxicillin (mTAP)] and a non-treated control group. Medicaments were removed after three weeks, and ERRM was applied to all specimens. The coronal portion of each root was then sliced into 2-mm-thick parallel transverse sections (2 slices per tooth, n=20 slices per group), and a push-out test was used to measure the bond strength of ERRM to dentin. Data were analyzed using Bonferroni-corrected Mann-Whitney tests, with the level of significance set at p<0.05.Results:The push-out bond strength of the CH group was significantly higher than that of the TAP, DAP and mTAP groups (p< 0.005). Furthermore, the bond strength of the control group was higher than the bond strength of both the DAP and mTAP groups.Conclusion:The use of CH in clinical practice may help improve the adhesion of ERRM to dentin.

BackgroundDue to the detrimental effect of blood contamination on the physico-chemical properties of mineral trioxide aggregate (MTA), obtaining an effective hemostasis in the surgical crypt during apical surgery is of paramount importance. The purpose of this in vivo study was to analyze the effect of Ankaferd Blood Stopper® (ABS) contamination on the biocompatibility of MTA.MethodsForty of 56 Wistar–Albino rats were divided randomly and equally into two groups (MTA and MTA-ABS) according to whether or not a hemostatic agent was used. The remaining 16 rats were designated as the control group. Rats in the experimental groups received freshly mixed MTA-Angelus in polyethylene tubes, which were inserted into monocortical bore holes created in their tibias. In the MTA-ABS group only, 0.5 mL of ABS solution was administered topically on the defect sites followed by implantation of MTA tubes. Inflammation, foreign-body reaction (FBR), necrosis, fibrosis, and new bone formation (NBF) were studied 7, 30, 60, and 90 days after implantation.ResultsOn day7, statistically significant differences were found in tissue reactions with regard to NBF and necrosis (p = 0.044 and p = 0.024, respectively), the latter being observed in 40 % of the samples only in the MTA-ABS group. Slight inflammation in all groups was confined to day-7 only. Mild necrosis was present in the MTA-ABS group only on day-7. Severity of the foreign body reaction and fibrosis was limited. New bone formation increased gradually over time in all groups, reaching a maximum on day-90.ConclusionsMTA and ABS-contaminated MTA are equally biocompatible. ABS does not impair the properties of MTA.Electronic supplementary materialThe online version of this article (doi:10.1186/s12903-016-0302-0) contains supplementary material, which is available to authorized users.

The aim of this study was to test the efficacy of three different electronic apex locators (EALs) in comparison with the radiographic working length determination. This study was conducted on the 211 root canals of 113 teeth in the undergraduate endodontic clinic. Under the referee of the research assistants, the students determined the working length by taking a periapical radiograph with the file in place initially and then electronically by use of three different apex locators. The research assistant observed the entire procedure based on the manufacturers' recommendations, and the measurements were recorded individually. Data were statistically analyzed using the NCSS-PASS 2007 program, one-way ANOVA and intraclass correlation coefficient at the 95% confidence level with significance set at p<0.05. Comparing the coincidence between measurements obtained with radiography and with the three EALs, the intraclass correlation coefficient revealed that the radiographic and electronic working length measurements were coincident in all groups of teeth included in this study.

Aim: The aim of this clinical study was to evaluate the effect of low-level laser therapy, used in conjunction with conventional canal disinfection techniques, on post-operative pain after single- and multi-visit root canal treatments for chronic apical periodontitis. Methodology: 100 volunteers were randomly divided into 4 groups. The main inclusion criteria were radiographic evidence of apical periodontitis (minimum size of 2.0 × 2.0 mm) and a diagnosis of pulpal necrosis confirmed by a negative response to vitality tests. All the root canals were prepared using a standard shaping technique and irrigation procedure. In Groups I and III, the root canals were obturated during the first visit following chemo-mechanical preparation. In Groups II and IV, the root canals were medicated with calcium hydroxide and obturated during a second visit, 1 week later. In Groups III and IV, after the chemo-mechanical preparation, the root canals were additionally irradiated by an 810-nm diode laser at 1.5 W output for 20 seconds. A modified visual analogue scale was used to measure pain at 4, 8, 12, 24, and 48 hours and 7 days after the treatment. Results: There was no statistically significant difference between the groups in terms of post-operative pain at any time during the observation period (p > .05). Post-operative pain occurred only at 8 and 12 hours and at 1, 2, and 3 days in all groups. There was no correlation between the results regarding age, gender, periapical index scores, or tooth type. Conclusion: The use of low-level laser therapy had no significant effect on the incidence of post-operative pain, and single-visit root canal treatment may be a strong alternative to multi-visit treatment. How to cite this article: Özkan Özcan H, Haznedaroğlu F, Gökyay S. Comparison of the incidence of post-operative pain after low-level laser therapy between single- and multi-visit root canal treatments for chronic apical periodontitis: A prospective randomized clinical trial. Int Dent Res 2021;11(1):30-7. https://doi.org/10.5577/intdentres.2021.vol11.no1.6   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Evaluation of deformation and fracture rates for nickel-titanium rotary instruments according to the frequency of clinical use Purpose To evaluate the deformation and fracture rates for ProTaper Universal (PTU) nickeltitanium rotary instruments according to the frequency of clinical use. Materials and MethodsA total of 619 PTU instruments (S1, S2, F1, F2, and F3) that have been used in the clinic by a single endodontist were collected over a period of 4 years. These instruments were grouped on the basis of one to three (Group A), four to six (Group B) and seven to nine (Group C) clinical uses (one canal = one use). All instruments were evaluated by a blinded investigator under a stereomicroscope at 15×-45× magnification for the presence of deformation and fracture. ResultsThe overall rates of deformation and fracture were 10% and 1.2%, respectively. The deformation and fracture rates for the S2, F1, and F2 instruments showed no significant differences among groups. However, fracture rate for S1 instruments in Group A was significantly higher than for those in Group B (p=0.025) and Group C (p=0.004). In Group C, the S1 instruments showed a significantly higher deformation rate compared with the S2 (p=0.04), F1 (p=0.008) and F2 (p=0.049) instruments; there were no other significant differences within groups. ConclusionUnder the conditions of the current study, frequency of use seemed to influence the deformation rates of PTU rotary instruments. Except S1, these instruments could be used without any fracture or deformation in up to 9 clinical cases by an experienced endodontist.