The risk of bonded fragment loss in crown-fractured anterior teeth managed by fragment reattachment: a systematic review and meta-analysis

To identify the factors affecting the risk of bonded fragment loss in crown-fractured anterior teeth managed by fragment reattachment. The study protocol followed the best practices of evidence-based medicine and was registered in PROSPERO. A comprehensive literature search was performed electronically in six databases (PubMed, Embase, SCOPUS, Web-of-Science, Lilacs, and Cochrane) on 18-09-2023. It was saved in EndNote-online and duplicates were removed. Selection of articles was performed in two stages, followed by data-extraction, risk of bias assessment, data-analysis, and meta-analysis. The quality of evidence for the outcomes was assessed by the GRADE-approach. The study included six articles that had similar selection protocols with variations in duration from trauma to treatment and the observation period. Only one study employed pre-attachment fragment preparation and three performed post-attachment reinforcements. Overall loss of fragment was 20% (95%CI–13,30%). When the risk ratio for loss of restoration or fragment was compared, it was found to be 2.21 (95%CI–1.52,3.21) in uncomplicated crown fractures, 2.54 (95%CI–1.35,4.79) in complicated crown fractures. The risk of bias was found to be low in two and moderate in four studies. Grade of evidence for all the outcomes was very low. Fragment loss was lowest in uncomplicated crown fractures where reinforcement had been performed, and highest when bonding was done in complicated crown fractures without reinforcement. The risk of fragment loss was higher than the loss of composite restorations.