Impact of cement- and screw- retained implant prostheses on marginal bone loss

Aim: The choice between retention systems in implant-supported prostheses impacts marginal bone loss (MBL), a key factor for implant longevity. Due to variability in the findings of systematic reviews, this overview aims to assess the methodological quality and synthesize available evidence from systematic reviews on the effects of cement- versus screw-retained implant-supported prostheses on MBL. Methods: Six databases were searched for systematic reviews comparing MBL in screw- versus cementretained implant-supported prostheses. The methodological quality was assessed using AMSTAR 2, and the MBL effects were classified as favoring cemented, no difference, or favoring screwed systems based on the conclusions of the reviews. Additionally, quantitative data on MBL at different intervals—up to 1, 3, 4, and more than 4 years—were extracted from primary articles and visually plotted for interpretation. Results: The search identified 8 systematic reviews, mainly classified as critically low quality, which found no significant difference in MBL between retention systems. Evaluating the quantitative data, both systems exhibited minor variations over time, with cemented implant-supported prostheses showing slightly less bone loss at the five-year follow-up. Beyond 4 years, both systems demonstrated similar MBL ranges. Conclusion: Both screw-retained and cement-retained implant-supported prostheses appear to be reliable options, with no significant difference in MBL observed in most systematic reviews, especially over longer follow-up periods. However, due to the low quality of existing systematic reviews, conclusions should be approached with caution, underscoring the need for betterdesigned studies to reach a clearer clinical consensus.