Long-term outcomes of adjacent and antagonistic teeth after implant restoration: a focus on patient-related factors.

Purpose: To investigate factors affecting the antagonistic and adjacent teeth in patients after implant restoration and prosthetic rehabilitation.

Methods: In total, 160 patients who visited Kyungpook National University Dental Hospital for implant surgery, prosthesis placement, and supportive periodontal therapy (SPT) were included in this study. The average follow-up period was 88.06 months, and the maximum was 175 months. Patients' history of smoking, diabetes, hypertension, and osteoporosis was investigated, and panoramic radiographs were taken after surgery and prosthetic treatment. During the follow-up period, extraction and prosthetic/endodontic treatments of the antagonistic and adjacent teeth were analyzed. The statistical analyses were performed using descriptive statistics, the chi-square test, the Fisher exact test, and multiple logistic regression analyses.

Results: Treatment was performed on 29.4% of the studied antagonistic teeth with extraction performed in 20.0% and prosthetic treatment in 10.0%. Furthermore, 19.4% of the studied adjacent teeth underwent treatment, of which extraction was performed in 12.5% and prosthetic treatment in 7.5%. The treatment rate for adjacent teeth was 25.3% in smokers, which was higher than that of non-smokers (12.3%) (=0.039). Patients who were non-adherent to SPT showed a significantly higher rate (19.6%) of antagonistic prosthetic treatment than did those who were adherent (5.5%) (=0.006).

Conclusions: Implant restoration can affect the adjacent and antagonistic teeth. Smoking, osteoporosis history, and absence of SPT may be risk factors for the treatment of the adjacent and antagonistic teeth.