Risk of Bias and Its Impact on Intervention Effect Estimates of Randomized Controlled Trials in Endodontics

Centric versus eccentric engine-driven endodontic instrument design for microbial load reduction-A systematic review and meta-analysis of randomised clinical trials

This systematic review assessed the clinical influence of centric and eccentric engine-driven instrument design for reduction in microbial load in infected root canal system. The literature search was conducted in electronic databases (PubMed, Cochrane Library, Scopus, Lilacs and Google Scholar) and grey literature till June 2022. The search strategy followed the PRISMA 2020 guidelines. Qualitative and quantitative synthesis was conducted based on the guidelines of the Cochrane Handbook. The risk of bias was assessed using the revised Cochrane criteria and quality of evidence was conducted using the Grading of Recommendation Assessment, Development and Evaluation tool. Out of 28 papers, only five papers met the inclusion criteria of this review. Studies showed reduction in microbial load after instrumentation using centric or eccentric instruments with no statistically significant difference in the meta-analysis. In conclusion, there is low-grade evidence suggesting that microbial reduction is similar using centric and eccentric instruments.

Clinical decision making of post-treatment disease

Root-filled teeth presenting with signs of post-treatment disease is a common finding in virtually every dental practice. There is both empirical and experimental evidence that, as long as the condition is asymptomatic, it is often left untreated. Professional judgements and decision making in endodontics as in any medical discipline are based on qualified estimations of the probability and the value of relevant outcomes. In this paper we describe various aspects of clinical decision making in general, from a descriptive as well as a normative point of view, but with a particular focus on the condition of the root-filled tooth with post-treatment disease. We review how attention to various types of uncertainties are relevant for the decision-making process. Additionally, we discuss the nature of value judgements and different concepts of health and disease which are important for understanding the complexity of the clinical decision-making process. We also refer to a set of principal rules that can guide the clinician's decision making in every-day practice in front of a case with endodontic post-treatment disease. Finally, we provide some aspects on the sometime cumbersome decision whether to go for a non-surgical or surgical method, whenever a decision on retreatment has been made.

The Effect of Trypsin-Chymotrypsin on Postoperative Pain after Single Visit Endodontic Treatment: A Randomized Controlled Trial

INTRODUCTION

The efficacy of trypsin-chymotrypsin in postoperative pain management following single-visit root canal treatment of teeth with symptomatic irreversible pulpitis was evaluated. Additionally, synergistic effects with nonsteroidal anti-inflammatory drugs and reported side effects were also investigated.

METHODS

This prospective, parallel, triple-blinded phase IV randomized controlled trial included 60 patients with mandibular first molars exhibiting symptomatic irreversible pulpitis. The patients were randomly allocated using computer software to one of four treatment groups (n = 15 each), and either ibuprofen (600 mg), ambezim-G (trypsin 5mg-chymotrypsin 5 mg), a combination of both, or a placebo drug were administered postoperatively. The participants scored pain intensity at different time-intervals using a numerical scale, and passive surveillance of harm was used to detect clinical safety. Age was compared between groups using a one-way analysis of variance test. Pain scores were analyzed using the Kruskal-Wallis and Friedman's tests and, if significant, Dunn's test was used for pairwise comparisons. The chi-square test was used to compare qualitative data, and the significance level was set at P value ≤ .05.

RESULTS

All interventions were found to be effective in reducing postoperative pain, and no statistically significant differences were observed between the ibuprofen, trypsin-chymotrypsin, and combination groups. However, all 3 groups differed significantly from the placebo group. The safety profile of the interventions did not differ significantly.

CONCLUSIONS

Trypsin-chymotrypsin exhibits comparable efficacy to nonsteroidal anti-inflammatory drugs. No synergistic effects occur when the 2 are used in combination. This is the first randomized controlled trial to assess the effects of proteolytic enzymes on postendodontic pain.

TRIAL REGISTRATION

clinicaltrials.gov, Identifier: NCT05479747.

Is Intracanal Cryotherapy Effective in Reducing Postoperative Endodontic Pain? An Updated Systematic Review and Meta-Analysis of Randomized Clinical Trials

This research aimed to assess the potency of intracanal cold therapy in diminishing postoperative endodontic pain. PubMed, Scopus, the Cochrane Library, EMBASE, the Web of Science, grey literature, and endodontic journals were used to identify randomized controlled clinical trials evaluating postoperative pain after a final irrigation with a cold irrigant (as an experimental group) and a room temperature irrigant (as a control group). The risk of bias was rated according to the Cochrane Collaboration's tool and the Grading Recommendation Assessment, Development, and Evaluation (GRADE) system was used to estimate the evidence quality. For the meta-analysis, a random effects model was utilized. The qualitative analysis contained 16 studies and the quantitative analysis contained 9 studies. The experimental groups showed a reduction in postoperative pain at 6 h (mean difference (MD) = -1.11; p = 0.0004; I2 = 72%; low quality evidence), 24 h (MD = -1.08; p = 0.003; I2 = 92%; low quality evidence), 48 h (MD = -0.38; p = 0.04; I2 = 81%; low quality evidence), and 72 h (MD = -0.69; p = 0.04; I2 = 90%; low quality evidence). A higher quality of evidence from more clinical trials is needed.

The impact of an enhanced infection control protocol on molar root canal treatment outcome - a randomized clinical trial

AIM

To evaluate the effect of an enhanced infection control protocol on root canal treatment outcomes and on microbial load within root canals after chemomechanical preparation.

METHODOLOGY

A total of 144 molar teeth from 139 healthy patients receiving primary root canal treatment were block randomized to a standard protocol (StP) or an enhanced infection control protocol (EnP). Both treatment arms adhered to current best practice recommendations, while the EnP comprised additional steps that included replacing rubber dams, gloves, files, all instruments and surface barriers at the time of canal filling to reduce the chances of iatrogenic contamination. Patients and radiographic examiners were blinded to the protocol used. Intracanal microbial samples were taken at baseline (S1) and after completion of chemomechanical preparation (S2). Microbial 16S rDNA copy numbers were enumerated by quantitative polymerase chain reaction (qPCR). Cone beam computed tomography (CBCT) scans were taken before treatment and at one-year follow-up. The outcome was assessed clinically and radiographically using CBCT by logistic regression modelling.

RESULTS

At one-year follow-up, 115 teeth were analysed (54 in StP and 61 in EnP). The percentage of favourable outcomes assessed by CBCT was 85.2% in the EnP and 66.7% in the StP. The odds of 12-month success was three times higher in the EnP group compared with the StP group (OR=2.89; p=0.022, CI: 1.17 - 7.15). The median bacterial reads were reduced from 8.1×10³ in S1 samples to 3.5×10³ in the StP group and from 8.6×10³ to 1.3×10³ in the EnP group. The enhanced protocol significantly reduced bacterial counts in pre-canal filling samples when compared to the standard protocol (p=0.009).

CONCLUSIONS

The implementation of a facile, enhanced infection control protocol in primary root canal treatment resulted in less detectable bacterial DNA before canal filling and significantly more successful outcomes at one year.

The reporting quality of split-mouth trials in orthodontics according to CONSORT guidelines: 2015-19

OBJECTIVES

To assess the reporting quality of split-mouth trials (SMTs) in orthodontic journals, and to identify factors associated with better reporting.

MATERIALS AND METHODS

Seven leading orthodontic journals were hand searched for SMTs published during 2015-19. The CONSORT 2010 guideline and CONSORT for within-person trial (WPT) extension were used to assess the trial reporting quality (TRQ) and WPT-specific reporting quality (WRQ) of included SMTs, respectively. A binary score (0 or 1) was given to each item of the guidelines, and total scores were calculated for TRQ (score range, 0-32) and WRQ (score range, 0-15). Univariable and multivariable linear regression analyses were performed to identify factors associated with TRQ and WRQ.

RESULTS

A total of 42 SMTs were included. The mean overall scores for TRQ and WRQ were 16.8 [standard deviation (SD) 7.1] and 5.6 (SD 2.3), respectively. Only 11 SMTs (26.2%) presented the rationale for using a split-mouth design. Key methodological items including random sequence generation (22/42, 52.4%), allocation concealment (9/42, 21.4%), and blinding (20/42, 47.6%) were poorly reported. Only six SMTs (14.3%) used a paired method for sample size calculation, and half (21/42, 50.0%) considered the dependent nature of data in statistical analysis. In multivariable analyses, higher TRQ and WRQ were both significantly associated with journal, reported use of CONSORT and funding status.

CONCLUSIONS

The reporting quality of SMTs in orthodontics has much room for improvement. Joint efforts from relevant stakeholders are needed to improve the reporting quality of SMTs and reduce relevant avoidable research waste.

Effectiveness of Intracanal Cryotherapy in Root Canal Therapy: A Systematic Review and Meta-analysis of Randomized Clinical Trials

INTRODUCTION

The effectiveness of intracanal cryotherapy for reducing postoperative pain is unclear. The objective of this systematic review was to evaluate the effect of intracanal cryotherapy on postoperative pain after root canal therapy in patients with pulpal or periradicular pathosis.

METHODS

We searched PubMed, Embase, Scopus, and the Cochrane Library as well as the top 3 endodontic journals for relevant articles. We included randomized controlled trials that included adults. Our main outcome was postoperative pain intensity measured with a validated scale. We assessed the risk of bias using the Cochrane criteria and the quality of the included studies using Grading of Recommendation Assessment, Development, and Evaluation. We used a random-effects model for meta-analysis.

RESULTS

Eight studies involving 810 patients were included. The overall risk of bias was moderate. Seven of 8 studies used a visual analog scale to measure pain intensity. Compared with controls, intracanal cryotherapy significantly reduced postoperative pain at 6 (mean difference = -1.37; 95% confidence interval [CI], -0.61 to -2.14; P < .05; I2 = 76%; moderate-quality evidence) and 24 hours after the procedure (mean difference = -1.43; 95% confidence interval, -0.70 to -2.15; P < .05; I2 = 89%; moderate-quality evidence). There was no significant effect on pain at 48 and 72 hours and 7 days after the procedure.

CONCLUSIONS

Moderate-quality evidence suggests that intracanal cryotherapy (ie, using cold saline irrigation as a final irrigant) significantly reduces the intensity of pain at 6 and 24 hours after root canal therapy. Future clinical trials assessing the effectiveness of intracanal cryotherapy are advocated.

Glossary for randomized clinical trials

Randomized clinical trials are positioned at the highest level of primary clinical evidence, as they are designed to be unbiased with a reduced risk of systematic error. The Consolidated Standards of Reporting Trials (CONSORT) statement was first developed in 1996 to improve the reporting quality of randomized clinical trials with updates being published subsequently. Recently, the Preferred Reporting Items for RAndomized Trials in Endodontics (PRIRATE) 2020 guidelines were developed exclusively for the field of Endodontics to address the suboptimal quality of randomized clinical trials submitted to Endodontic journals, which result in many being rejected. A principal flaw in submissions is the fact that many authors are unclear on the keys terms that should be used when developing manuscripts for publication. Clearly, authors should be aware of the most common terms used when conducting and reporting randomized clinical trials. Hence, the aim of the current paper is to present a comprehensive glossary of the terminology used in randomized clinical trials in order to assist authors when designing, executing and writing-up randomized clinical trials.