A review of failure modes in teeth restored with adhesively luted endodontic dowels.

PURPOSE Previous clinical studies indicated loss of retention between dowel and tooth was a major cause of failure for passive endodontic dowels. Advances in luting cement technology may have improved the retention of dowels. The purpose of this systematic review was to determine the clinical failure modes for dowel/core/crown restorations luted using resin-based cements that are either self-etching or used in conjunction with a bonding agent. MATERIALS AND METHODS PubMed was searched for English language, peer-reviewed clinical research following restorations for 2 years or longer. For inclusion, a study group must have followed more than 50 permanent teeth restored using a dowel luted with resin cement and a bonding agent. Furthermore, more than 80% of the restorations must have received a nonresin crown. RESULTS Fifteen studies met the inclusion criteria and reported a total of 187 failures from 3046 restorations. The commonly reported causes of failure were dowel debonding (37% of all failures and primary cause in 8 of the 17 reporting study groups) and endodontic lesions (37% of all failures and primary cause in 6 of the 11 reporting study groups). CONCLUSIONS Loss of retention remains a major mode of failure even for passive, nonmetal dowels luted by resin cements with a bonding agent. The exact nature and underlying causes of debonding have not been adequately investigated.