Comparator choice in cariology trials limits conclusions on the comparative effectiveness of caries interventions

Atraumatic vs conventional restorative treatment for root caries lesions in older patients: Meta- and trial sequential analysis

OBJECTIVES

We aimed to appraise the comparative clinical efficacy of atraumatic restorative treatment (ART) versus conventional restorative treatment (CT) using a meta-analysis, and assessed the robustness of evidence by trial sequential analysis (TSA).

BACKGROUND

Due to its simplified clinical approach, ART may be advantageous over CT for restoration of root caries lesions in institutionalised older patients.

METHODS

Three electronic databases (PubMed, Embase and Cochrane CENTRAL) were screened, and hand searches and cross-referencing performed to identify randomised controlled trials reporting on survival of ART vs CT for restoration of root caries in older patients. Trial selection, data extraction and risk of bias assessment were performed by two independent reviewers. ART and CT were compared using fixed- or random-effects pairwise meta-analysis for per-protocol (PP), intention-to-treat (ITT) and best-case scenarios. TSA was used to control for risk of random errors.

RESULTS

A total of 235 studies were identified, and three trials involving 130 patients (463 restorations) were included. Risk of bias was high or moderate in all but one trial. ART was associated with a significantly increased risk of failure (OR [95% CI] 2.06 [1.06/4.00]) in PP- but not in ITT analysis (1.36 [0.92/2.02]). Analyses for best-case scenarios found great uncertainty introduced by attrition. No firm evidence was reached according to TSA.

CONCLUSIONS

For restoration of root caries, there is insufficient data to clearly rule out whether differences between ART and CT exist. Limited available data indicate there might be an increased risk of failure for ART.

Comparator Choice in Studies Testing Endodontic Instrument Fatigue Resistance: A Network Analysis

AIMS

Endodontic instruments are frequently compared against each other for their cyclic fatigue resistance (CFR). It is unclear what drives the comparator choice in CFR studies, and how comparators and comparisons have evolved over time. We aimed at evaluating CFR study networks, hypothesizing that indications and instrument properties (alloy, manufacturer) drive comparisons.

METHODS

A systematic review was performed via Medline and Embase (1986-2017). In vitro studies analyzing the CFR of ≥2 engine-driven instruments in an artificial curved root canal system were included. We classified instruments according to name, alloy, and manufacturer. Study networks were analyzed using social network analysis techniques.

RESULTS

Eighty-five studies on 56 different instruments (9 alloys, 17 manufacturers) were included. For instruments, a low-density (0.19), highly clustered (0.71) network with 3 separate subnetworks (for glide path, shaping, and retreatment instruments) emerged. Certain instruments (ProTaper Universal [Dentsply Maillefer, Ballaigues, Switzerland], Mtwo [VDW Dental, Munich, Germany]) served as hub nodes and possible gold standards. Conventional Nickel-Titanium was the most frequently used alloy. Few manufacturers dominated the network. The diversity of tested instruments, alloys, and manufacturers increased in recent years.

CONCLUSIONS

Comparisons of CFR were usually made along indications. Some instruments and alloys (conventional Nickel-Titanium) dominated the networks. Overall risk of bias by comparator choice seems moderate; however, the evidence on certain, less often tested instruments may not be robust. Factors underlying the network geometry (eg, sponsorship) should be explored.