Peri-Implant Supracrestal Tissue Characteristics Related to Abutment Materials: A Comparative Histomorphometry Study.

Background
The peri-implant soft tissue integration is critical to maintain peri-implant health and the long-term success of dental implant rehabilitations.
Aim
This comparative histomorphometry study aims to characterize the peri-implant soft tissues (PIST) around experimental abutments made of titanium (Ti), dental resin (Re), and polyetheretherketone (PEEK).
Methods
Thirty bone-level implants were placed, each receiving an experimental transmucosal healing abutment made of one of the three materials. After an 8-week healing period, the abutments and surrounding tissues were harvested and prepared for histological and histomorphometric analyses. Dimensions of sulcus depth, epithelial and connective tissue adhesion were measured. In addition, the abutment surface characteristics, levels of inflammation, plaque accumulation, and peri-implant bone level changes were evaluated.
Results
The dimensions of the different components of the PIST were comparable across the three experimental groups. The mean overall dimensions of the PIST were 2.68 ± 0.51 mm for Ti, 2.66 ± 0.47 mm for Re, and 2.32 ± 0.55 mm for PEEK. Mean sulcus depth was 0.71 ± 0.69 mm for Ti, 0.74 ± 0.50 mm for Re, and 0.68 ± 0.63 mm for PEEK. Mean junctional epithelium was 1.82 ± 0.67 mm for Ti, 1.56 ± 0.47 mm for Re, and 1.53 ± 0.40 mm for PEEK. Mean harvested connective tissue (until abutment platform) was 0.30 ± 0.29 mm for Ti, 0.36 ± 0.38 mm for Re, and 0.09 ± 0.10 mm for PEEK. However, the resin group exhibited significantly more supramucosal biofilm adhesion (p = 0.026).
Conclusion
The PIST around abutments made of PEEK, resin, or titanium tend to develop in a similar pattern. However, longer observation periods are required to evaluate the long-term effects.