Retrospective study on the clinical and radiographic outcomes of 2.8 mm diameter implants supporting fixed prostheses up to 11 years.

Objectives: This study aimed to report the clinical and radiographic results of 2.8 mm two-piece narrow diameter implant (NDI) supporting fixed restorations.

Materials and methods: Clinical and radiographic data of 54 NDIs in 32 patients were retrospectively assessed after 2 to 11 (mean 8.17) years of follow-up. Clinical and radiographic measurements were taken. Survival rate, implant and prosthesis failure, pink aesthetic scores (PES), white aesthetic scores (WES), bleeding on probing (BOP), probing depth (PD), marginal bone loss (MBL), and mechanical and biological complications were evaluated.

Results: An implant failed during the follow-up period, resulting in a cumulative survival rate of 98.15% at the implant level and 96.88% in the patient. The total mean values of PES and WES for 2.8 mm NDIs were 7.09 ± 1.15 (range: 3.33-9.00) and 7.42 ± 1.03 (range: 3.67-9.33). The prevalence of sites with positive BOP was 38.14 ± 29.77%. The mean PD value was 2.46 ± 0.62 mm. The average MBL was 1.15 ± 0.74 mm (range: 0.25-4.03 mm). No implant or abutment fracture was detected. A veneer chipping was present in one patient, and a loose crown appeared in another patient. Two implants (3.7%) and two patients (6.3%) were diagnosed with peri-implantitis.

Conclusion: Within the limitation of the study, the results indicate that the use of two-piece 2.8 mm NDI for the fixed prosthetic rehabilitation of edentulous regions with reduced interdental and/or buccal-lingual width is viable.