Complications of screw restorations: a systematic review and meta-analysis.

PURPOSE: To assess the technical and biological complications of screw cement-retained implant-supported full-arch dental prostheses. MATERIALS AND METHODS: An electronic search was conducted on Medline/PubMed and Cochrane databases in February 2019; irrespective of any time restrictions using MeSH terms. All studies were first reviewed by abstract and subsequently by full-text reading. Further hand search was performed to identify other related references. Articles only related to cement-retained and/or screw-retained reconstructions in full-arch fixed dental prostheses (FDP) were included. RESULTS: The initial literature search resulted in 3670 papers. 3478 articles remained after removing duplicate articles, and 3439 articles were further excluded by the reviewers after the abstract screening, which resulted in a selection of 39 studies. 12 studies were further excluded due to not fulfilling the inclusion criteria. Hand searching resulted in two additional papers being included, and finally, 29 articles were included in this review. Screw-retained full-arch fixed dental prostheses have fewer complications than cemented reconstructions. Biological complications such as marginal bone loss > 2 mm occurred more frequently in cemented reconstructions, and technical complications such as screw-loosening and screw fracture occurred more in screw-retained reconstructions. CONCLUSION: Cemented reconstructions exhibited more biological complications (implant loss, bone loss > 2 mm) and screw-retained prostheses exhibited more technical problems. Clinical outcomes were influenced by both fixations in different ways. The screw-retained restorations were more easily retrievable than cemented ones, therefore, technical and eventually biological complications could be treated more easily. For this reason, and for their higher biological compatibility, these reconstructions are preferable.