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

Comparing the anaesthetic efficacy of 1.8 mL and 3.6 mL of anaesthetic solution for inferior alveolar nerve blocks for teeth with irreversible pulpitis: a systematic review and meta-analysis with trial sequential analysis

Background The scientific literature is contradictory in relation to selecting the appropriate volume of local anaesthetic solution for inferior alveolar nerve blocks (IANB) when attempting to anaesthetize mandibular teeth with irreversible pulpitis. Objectives To compare the efficacy of 1.8 and 3.6 mL of the same anaesthetic solution for IANBs when treating mandibular teeth with irreversible pulpitis. Methods A literature search was performed in PubMed, Scopus and EBSCOhost databases until May 2020. Randomized clinical trials published in English, comparing 1.8 with 3.6 mL of the same anaesthetic solution for IANBs in permanent mandibular teeth with irreversible pulpitis, were included. The risk of bias of the included trials was appraised using the revised Cochrane risk of bias tool. A meta-analysis was performed using the random-effects model. The effect of random errors on the results of the meta-analysis was evaluated by trial sequential analysis and the quality of evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Results Four clinical trials involving 280 teeth from patients with ages ranging from 18 to 65 years were included. Among the four trials, three were categorized as having a ‘low’ risk of bias and one was categorized as having ‘some concerns’. The primary meta-analysis revealed that 3.6 mL of anaesthetic solution when administered for IANBs was associated with significantly greater success rates compared with 1.8 mL (RR = 1.94; 95% CI, 1.07, 3.52; I2 = 77%). Similarly, the results of the sensitivity analysis (restricting trials only to those that used the Heft-Parker visual analogue pain scale) revealed that the use of 3.6 mL significantly increased the success of IANBs compared with 1.8 mL. The trial sequential analysis confirmed the evidence for the beneficial effect of 3.6 mL to achieve success for IANBs was ‘conclusive’. The quality of evidence was graded as ‘high’. Conclusion Increasing the volume of anaesthetic solution from 1.8 to 3.6 mL improved the success rate for IANBs in mandibular molars with irreversible pulpitis. The quality of the evidence was ‘high’. Future high-quality clinical trials are required with different types of anaesthetic solutions and other types of teeth

Influence of remaining axial walls on of root filled teeth restored with a single crown and adhesively bonded fibre post: A systematic review and meta-analysis

Objectives To synthesise evidence on structural failures and prevalence of post-treatment endodontic disease (PTD) in anterior and posterior root filled teeth with a single crown and adhesively bonded fibre post with regards to the number of axial walls. Data An electronic search was performed, no language constraints or restriction on the year of publication were applied. Sources PubMed, Medline, Cochrane and Scopus on 13th of July 2021. Study selection Clinical studies that reported the remaining number of axial walls for permanent anterior and posterior root filled teeth (RFT) restored with single crowns and adhesively bonded fibre posts with a minimum of 1 year follow-up were included. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines [1] were used. The number of axial walls and the success/failures were analysed as follows: fibre post and/or core decementation, post and/or core fracture and post treatment endodontic disease, and root fracture. Conclusions A total of 811 studies were identified with 5 meeting the inclusion criteria. The two randomized controlled trials included had ‘some concerns’ as determined by the Cochrane risk-of-bias 2 tool while the Newcastle-Ottawa scale found low risk of bias for the remaining three studies. The random effects model for subgroup meta-analysis revealed failures for posterior RFT increased with decreasing numbers of remaining walls. Failures for 0 remaining walls were 23% (95% CI = 10% - 36%) and for one remaining wall 15% (CI: 3% -26%), irrespective of follow-up times. Fibre post debonding and PTD increased with decreasing numbers of walls. Relative & catastrophic failure of posterior teeth restored with a fibre post and single crown after root canal treatment increased with decreasing numbers of remaining axial walls. Clinical significance This synthesis is unique as it minimizes the presence of confounding factors by reviewing evidence of failures and post-treatment endodontic disease associated with teeth restored with single crowns. Therefore, it provides valuable predictive evidence of potential coronal restoration catastrophes and post-treatment endodontic disease associated with root filled teeth

A new system for classifying tooth, root and canal anomalies

Understanding the normal anatomical features as well as the more unusual developmental anomalies of teeth, roots and root canals is essential for successful root canal treatment. In addition to various types of root canal configuration and accessory canal morphology, a wide range of developmental tooth, root and canal anomalies exists, including C-shaped canals, dens invaginatus, taurodontism, root fusion, dilacerations and palato-gingival grooves. There is a direct association between developmental anomalies and pulp and periradicular diseases that usually require a multidisciplinary treatment approach to achieve a successful outcome. A number of classifications have categorized tooth, root and canal anomalies; however, several important details are often missed making the classifications less than ideal and potentially confusing. Recently, a new coding system for classifying root, root canal and accessory canal morphology has been introduced. The purpose of this article is to introduce a new system for classifying tooth, root and canal anomalies for use in research, clinical practice and training, which can serve as complementary codes to the recently described system for classifying root, as well as main and accessory canal morphology