Proximal contact loss between implants loaded for more than 10 years and adjacent teeth

Recent studies have reported a high long-term success rate of dental implants however, various complications have also been observed, including proximal contact loss (PCL) between the implant and the adjacent teeth. PCL is frequently observed clinically and can potentially harm both the implant and adjacent teeth. This study examined the prevalence of PCL between implants that had functioned for more than 10 years and adjacent teeth in Korean patients, particularly those with a history of periodontal disease.

Fixed dental implants placed at the Department of Periodontics, Pusan National University Dental Hospital, were selected for this study. All implants selected had been functioning for more than 10 years, with at least 1 adjacent natural tooth in the mesial or distal position. Patient-, implant-, and tooth-related factors were evaluated. The chi-square test and Fisher exact test were used to assess the associations of PCL with these factors, with all statistical analyses performed using SPSS 29.0 and a significance level of 0.05.

This study included 142 implants and 188 adjacent teeth from 101 patients. The overall PCL rate was 53.7%, with 65.6% occurring on the mesial aspect, and 28.3% on the distal aspect. Among the factors analyzed in relation to PCL, implant placement in the molar region and several adjacent tooth-related factors namely plaque accumulation, mobility, bleeding on probing, and pocket depth of 4mm or greater were significantly associated with PCL (P<0.05).

Dental implants functioning for more than 10 years exhibited a high incidence of PCL, exceeding 50%, which occurred more frequently on the mesial side than on the distal side. Additionally, implant positioning in the posterior region and poor periodontal condition of the adjacent teeth were significantly correlated with PCL.