[Effect of zirconia personalized gingival penetration on peri-implant soft and hard tissue of thin gingival biotypes in the anterior region: a retrospective study].

ABSTRACT

Objective: To investigate the effect of zirconia personalized gingival structure on peri-implant soft and hard tissue stability after single-tooth implant restorations in patients with thin gingival biotypes in the anterior region, with a view to provide a clinical guideline. Methods: This retrospective study included 20 patients with thin gingival biotype and implant restorations in the anterior region. These patients included 9 males and 11 females, and the age was (35.2± 10.3) years. The patients were from the Department of Periodontal Implantology, Stomatology Hospital, Southern Medical University from January 2018 to December 2022. Computer-aided design/computer-aided manufacturing (CAD/CAM) techniques were used to fabricate a titanium base zirconia personalized gingival structure to maintain the soft-tissue perforated gingival contour of the anterior esthetic zone. This structure consists of two modalities titanium base + zirconia outer crown or titanium base personalized zirconia abutment + zirconia outer crown. Clinical outcomes were recorded immediately and after delivery of the final restorations. Implant retention was recorded, esthetic scoring was performed using the pink esthetic index, the amount of bone resorption at the implant margins was measured based on digitized apical radiographs, and periodontal health was evaluated using the modified plaque index and the modified bleeding index. Results: The survival rate of the 20 implants was 100% after 3 years of wearing the final restorations, with a pink aesthetic score of 9.3±0.9. Bone resorption at the proximal and distal mesial margins of the implants was 0.09 (-0.21, 0.20) mm, 0.17 (-0.12, 0.27) mm after 3 years, respectively, and the difference was not statistically significant when compared to bone resorption immediately after placement of the final restoration [0(0, 0) mm] (Z=-1.03, P=0.394; Z=-2.05, P=0.065). Conclusions: Zirconia personalized gingival structure maintains the stability of peri-implant hard and soft tissues of thin gingival biotypes in the anterior region.