Marginal Bone Changes Around Tissue-Level Implants After Prosthesis Delivery: A Multicenter Prospective Study.

INTRODUCTION

Early marginal bone loss (EMBL) is a non-infective phenomenon occurring around the implant neck from placement to the first year of prosthetic function, being influenced by both surgical and prosthetic factors. This multi-center prospective study assesses the impact of different variables potentially influencing marginal bone stability during the period from crown delivery to 18 months of functional loading.

METHODS

Forty-seven patients requiring a single posterior mandibular implant were selected according to specific criteria. Tissue-level implants were placed at different crestal bone levels based on vertical mucosal thickness and followed in an unsubmerged healing protocol, as described in a previous study evaluating peri-implant bone levels (PBL) from implant placement (T0) to crown delivery (T1). The present study continues this evaluation, focusing on MBL from T1 to 18 months post-loading (T2). Host-related factors (age, gender, smoking, history of periodontitis, vertical mucosal thickness) and specific prosthetic parameters, including crown mesio-distal dimension, emergence angle, and transmucosal collar height were recorded. Multiple linear regression analysis explored associations between MBL and prosthetic or patient-related factors, with significance set at p < 0.05.

RESULTS

Marginal bone levels remained stable from T1 to T2, with no significant association between MBL and host-related factors or defined prosthetic variables. However, total MBL from T0 to T2 was significantly higher around implants with thin mucosa at T0 compared to medium and thick mucosa. Multivariate analysis (T0-T2) identified thin mucosa and smoking as significant MBL predictors.

CONCLUSION

From T1 to T2, marginal bone levels around tissue-level implants remain stable, with no significant influence from variables analyzed. Conversely, peri-implant bone resorption between T0 and T2 is significantly associated with thin mucosa (primarily affecting T0-T1) and smoking.

TRIAL REGISTRATION: www.

CLINICALTRIALS: gov: NCT05363306.