Limited evidence on best material for retrograde root fillings

Data sourcesCochrane Oral Health's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline Ovid, Embase Ovid, LILACS, BIREME Virtual Health Library, OpenSIGLE, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, Chinese BioMedical Literature Database, VIP (in Chinese), China National Knowledge Infrastructure and Sciencepaper Online. No restrictions on language or date of publication were placed.Study selectionRandomised controlled trials (RCTs) that compared different retrograde filling materials, with clinical or radiological assessment for success over a minimum follow-up period of 12 months.Data extraction and synthesisTwo review authors extracted data independently and in duplicate, and subsequently carried out risk of bias assessment for each eligible study following Cochrane methodological guidelines. Original trial authors were contacted for any missing information.ResultsSix randomised controlled trials were included, with 916 participants involving 988 teeth. All these studies had a high risk of bias. Comparisons of five different retrograde filling materials were undertaken, including MTA versus intermediate restorative material (IRM), MTA versus super ethoxybenzoic acid cement (Super-EBA), Super-EBA versus IRM, dentine-bonded resin composite versus glass ionomer cement and glass ionomer cement versus amalgam.Grouping of data from different studies was minimal and provided limited evidence for each comparison. All studies showed a risk ratio of approximately one, indicating that there is weak or little evidence that any of the materials are superior. All of the studies displayed very low quality of evidence. None of these studies reported adverse events.ConclusionsCurrently there is insufficient evidence to determine which material is preferable for retrograde filling. Further high-quality RCTs are required for this.