Objective: A systematic review and meta-analysis were conducted to determine whether there are postoperative pain differences resulting from rotary and reciprocation engine-driven instrumentation motions in non-surgical endodontic treatment or retreatment at 12, 24, and 48 hours. Methods: Four electronic databases (PubMed, Embase, Cochrane Library, and Scopus) were searched to identify randomised controlled trials that compared the effects of rotary and reciprocating instrumentation motions on postoperative pain. Two authors independently screened the search results, extracted the data, and assessed the quality using the Cochrane risk of bias tool. Due to numerous variables across studies, the random effect inverse variance method for meta-analysis was applied. When significant heterogeneity among studies was present, the random effects multi-variable meta-regression analysis was performed to determine the source of heterogeneity. Results: At all time intervals, the incidence of postoperative pain was higher in the reciprocating instrumentation group, but was not statistically significant. There was no significant difference in the analgesic intake between groups. Meta-regression analysis determined study population sizes as a significant heterogeneous factor, while significance was not observed for preoperative pain or the pulpal diagnosis. Conclusion: There was no difference in postoperative pain at 12, 24, and 48 hours after non-surgical root canal treatment and retreatment, using reciprocating or rotary instrumentation motions.

Background. Mineral trioxide aggregate (MTA) is a commonly used endodontic biomaterial. The physicochemical properties of MTA have a crucial role in designating clinical outcome, and different factors can affect these properties. Various methods have been used for mixing MTA, including manual, mechanical, and ultrasonic. The aim of this systematic review was to evaluate the effect of different mixing methods on the physicochemical properties of MTA. Materials and Methods. Electronic databases including PubMed, Embase, Web of Science, and Scopus were searched up to May 2022. In order to cover gray literature, the ProQuest and Google Scholar databases were also searched to detect theses and conference proceedings. For quality assessment of the included studies, we used a modified version of the Cochrane risk of bias tool for randomized controlled trials (RCTs). Experimental studies which had assessed at least one property of MTA and compared at least two different mixing methods of MTA were included in this study. All animal studies, reviews, case reports, and case series were excluded. Results. Fourteen studies were included. The results showed that the ultrasonic mixing method significantly improved some MTA characteristics, including microhardness, flowability, solubility, setting time, and porosity. However, the mechanical mixing method improved other properties including flowability, solubility, push-out bond strength, and hydration. The manual mixing method showed inferior results compared to other mixing methods in terms of microhardness, flowability, solubility, setting time, push-out bond strength, porosity, and hydration. Different mixing methods had a similar effect on compressive strength, sealing ability, pH and calcium ion release, volume change, film thickness, and flexural strength of MTA. Conclusion. Mechanical and ultrasonic mixing methods are superior to the manual mixing method in terms of improving physicochemical properties of MTA. No report of selection bias and varieties in methodologies were limitations of evidence.

This study aimed to determine the effects of various lasers on dental implants’ surface characteristics. Nine explanted dental implants were included. Two implants were randomly allocated to four intervention groups, namely, diode (2 W, 810 nm, 10 s), CO2 (2 W, 10600 nm, 10 s), Er : YAG (200 mJ/20 Hz, 2940 nm, 10 s), and Er, Cr : YSGG (200 mJ/20 Hz, 2780 nm, 10 s) groups and one control group. After laser irradiation, all implants were imaged with scanning electron microscopy. Qualitative changes on the surface of implants were evaluated. Quantitative surface changes at the threads and between the threads were assessed by software using depression and prominence plots. The paired t-test was used for statistical analysis. Diode laser irradiation showed the least surface changes while the Er : YAG group showed the greatest surface changes. Furthermore, CO2 and Er : YAG laser irradiation significantly altered the mean profile area at the threads ( p < 0.05 ), while CO2 and Er, Cr : YSGG laser irradiation significantly altered the mean profile area between the threads ( p < 0.05 ). Diode laser irradiation does not alter the implant surface characteristics. However, the use of CO2, Er : YAG, and Er, Cr : YSGG lasers on titanium implant surfaces is discouraged as they damage the titanium implant surfaces.

This systematic review (PROSPERO‐CRD42020147333) aimed to compare the effects of conservative, ultraconservative and truss access cavities with traditional access cavities on the load capacity of root‐canal‐treated teeth. Online databases were searched until December 2021, and 25 ex vivo studies in which the effects of different access cavities on load capacity of permanent teeth had been investigated were included. Quality assessment was completed using a modified risk of bias tool for in vitro studies adapted from previous studies. Meta‐analysis was performed using the maximum‐likelihood‐based random‐effects model with similar groups. Conservative access cavities significantly improved the load capacity of maxillary premolars (p < 0.01 [−1.32, −0.028]) and molars (p < 0.05 [−0.89, −0.02]) compared to traditional access cavities. Additionally, truss access cavities significantly improved the load capacity of mandibular molars with (p < 0.05, [−1.18, −0.02]) mesio‐occluso‐distal cavity preparations. Higher levels of evidence are needed to determine the long‐term implications of minimal preparations for treatment outcomes.

Objective: To determine if identical dental shade guides can be used interchangeably considering their precision.Materials and methods: Twenty Vita classical (VC) and Vita 3D-Master (VM) shade guides were subjected to spectrophotometric measurements and their CIELab values were measured in three shade tab regions: incisal, middle, and cervical and also in total. The mean L*, a*, and b* values for analogous shade tabs were calculated to identify CIELab values for typical shades. ΔE 00 color differences between a typical shade and its analogous shade tabs were measured. ΔE 00 values were compared with perceptibility (ΔE 00 = 0.8) and acceptability (ΔE 00 = 1.8) thresholds using one-sample t test (α = 0.05). An error was considered when the ΔE 00 value was greater than the threshold. Subsequently, the shade guides' precision scores were calculated.Results: Mean ΔE 00 values ranged between 0.3 and 0.5 for VC tabs and between 0.3 and 0.6 for VM tabs. Precision scores for both shade guides ranged from 83.3% to 100%, considering the perceptibility threshold. Regarding the acceptability threshold, precision scores for VC ranged from 93.3% to 100%, while the precision scores for VM were 100%.Conclusions: Owing to high precision of VC and VM, identical dental shade guides can be used interchangeably.Clinical Significance: Using identical dental shade guides interchangeably may affect the color results of restorative treatments. This study identified high levels of precision for identical shade tabs of Vita classical and Vita 3D-Master across different batches. Thus, similar dental shade guides can be used interchangeably.