ASSESSMENT OF PERI-IMPLANT TISSUE BEHAVIOR AND ESTHETIC OUTCOMES OF BIOLOGICALLY ORIENTED PREPARATION TECHNIQUE (BOPT) IMPLANT-SUPPORTED CROWNS: A RANDOMIZED CLINICAL STUDY

Kholoud Mohamed Mahmoud Soliman*, Ossama Saleh Abd El Ghany, Mona Hossam Eldin Mandour

ABSTRACT

Aim: to compare peri-implant tissue behavior, marginal bone level and Pink Esthetic Score (PES), associated with custom zirconia implant abutments fabricated according to the Biologically Oriented Preparation Technique (BOPT) and conventional shoulder-finish-line zirconia abutments. Materials and Methods: Sixteen patients presenting with a single missing tooth in the esthetic zone were enrolled in this randomized clinical study and equally allocated into two groups. Group I received custom zirconia shoulder abutments on titanium bases, whereas Group II received custom zirconia BOPT abutments on titanium bases. All implants were placed using a two-stage delayed-loading protocol and restored through a fully digital workflow. Clinical and radiographic evaluations were performed at crown delivery, 3 months, and 6 months. Outcome measures included soft tissue thickness, marginal bone level, marginal bone loss, Pink Esthetic Score (PES. Results: Both groups demonstrated successful clinical outcomes throughout the follow-up period. Group II showed significantly better preservation of marginal bone levels than Group I at both 3 and 6 months (P < 0.0001). Overall marginal bone loss was significantly lower in the BOPT group (0.22 ± 0.05 mm) compared with the shoulder-abutment group (0.42 ± 0.12 mm). The percentage reduction in bone level was also significantly lower in Group II (−1.92 ± 0.39%) than in Group I (−3.89 ± 1.28%). Soft tissue behavior and esthetic outcomes favored the BOPT group. Conclusions: Within the limitations of this study, BOPT zirconia abutments demonstrated superior preservation of peri-implant hard and soft tissues and improved esthetic outcomes compared with conventional shoulder zirconia abutments.

Keywords: Dental implants; BOPT; zirconia abutment; Pink Esthetic Score; marginal bone loss.