Objectives: This systematic review compares the impact of ball and locator attachments on marginal bone loss in implant-retained overdentures in completely edentulous patients.
Method and materials: Following PRISMA guidelines, health science librarians completed literature searches from inception to 17 March 2023 in seven databases. There were 15,686 items exported to EndNote from Embase.com, CINAHL (EBSCO), Cochrane Library, Ovid MEDLINE-ALL, PubMed, Scopus, and Web of Science. Hand-searching added four more articles. After deduplication, 6,756 items were screened for eligibility. Twenty-nine studies were assessed by full text, of which ten studies, involving 424 subjects, were included in the review. Risk of bias assessment was conducted using the Cochrane risk-of-bias tool and the Newcastle–Ottawa scale. A meta-analysis was performed to synthesize and analyze the collective data from the selected studies.
Results: The included studies used diverse methodologies, implant systems, and loading protocols. Most studies reported no significant difference in marginal bone loss between ball and locator attachments. The meta-analysis revealed high heterogeneity.
Conclusion: The results of this systematic review suggest that ball and locator attachments exhibit similar performance in terms of marginal bone loss in implant-retained overdentures. However, the limited number, risk of bias, and heterogeneity of studies highlight the need for standardized research designs and larger sample sizes in future investigations to draw more definitive conclusions.