Occlusal Changes on implant-supported single crowns with one year follow-up after loading: A systematic review and meta-analysis

Objective This systematic review evaluated the occlusal changes after loading with implant-supported single crowns. Sources An electronic literature search was conducted in PubMed, Embase and Cochrane library for randomized (RCTs) or non-randomized controlled clinical trials (CCTs), with a minimum of 10 patients. Study selection Studies reporting the occlusal force changes on implant-supported single crowns – with natural teeth as antagonist - measured at baseline and after loading periods were included. 4 CCTs including 133 ISCs in posterior sites were included for meta-analysis. All analyzed ISCs had no contact at a light bite and a light contact at a heavy bite in MIP at loading (baseline). Data The relative occlusal forces (ROFs) of each implant-supported single crown (ISC) or control tooth (CT) were extracted. ROFs were defined as percentage of the total occlusal force of the entire dentition at maximum intercuspal position (MIP). A meta-analysis was conducted to compare the ROF changes at different follow-up periods and the weighted mean differences in ROF between ISCs and CTs were pooled and analyzed.The amount of change in ROF was significantly lower in 6 to 12 months after loading comparing the follow-up period between baseline and 6 month (p<0.05). At baseline and 3-month follow-up, CTs presented significant higher ROF than ISCs (p<0.05), while no significant difference was found after half year following. Conclusions : This study showed that the ROF changes significantly over time after loading of ISCs. It might prove that the occlusal concept defined at the time of prosthetic delivery changes or adapts naturally over time. Clinical significance : The function of specific implant occlusal concept (no contact at a light bite and a light contact at a heavy bite in MIP) is limited over time and careful monitoring and occlusal adjustments should be recommendable during the first-year follow-up.