Clinical outcomes of using a prosthetic protocol to rehabilitate tissue-level implants with a convergent collar in the esthetic zone: A 3-year prospective study

Statement of problem: Whether increasing the space for peri-implant soft tissues by using implant systems with conical or convergent transmucosal components would improve tissue stability and esthetics is unclear. Purpose: The purpose of this prospective clinical study was to evaluate the clinical and esthetic outcomes of using tissue-level implants with a convergent collar in the esthetic zone that had been rehabilitated following the biological oriented preparation technique (BOPT) approach after a 3-year follow-up period. Material and methods: Sixteen participants with at least 1 nonrestorable tooth in the maxillary anterior region or with congenitally missing maxillary lateral incisors were enrolled, and tissue-level implants with a convergent collar were inserted 3 months after extraction. The implants were restored with cemented single crowns designed according to the BOPT protocol. Bone resorption and the pink esthetic score were evaluated over a 3-year period. Results: Fifteen participants (mean age: 54.6 years) were evaluated over the 3-year period (total: 16 implants). One participant with 1 implant relocated dropped out of the study. The 3-year implant cumulative survival rate was 100%. The mean ±standard deviation bone-level change was 0.071 ±0.11 mm. The mean pink esthetic score was 8.5 ±1.59, range 4-10. Conclusions: The use of the BOPT protocol to restore tissue-level implants with a convergent collar achieved good esthetic results and maintained stable soft and hard peri-implant tissues