Peri-implant Bone and Periodontal Characteristics Associated with Caries Formation in Adjacent Teeth

Background: Preserving the integrity of teeth adjacent to dental implants is crucial for longterm success. This study evaluated whether radiographic bone parameters, spatial distances, and clinical periodontal indices are associated with new carious lesions in teeth neighboring posterior single implant-supported restorations.

Methods: A cross-sectional study was conducted on 50 partially dentate adults (27 females, 23 males; mean age 51.2 ± 10.5 years) with single posterior implants loaded for at least 1 year. Clinical parameters, including probing depth, plaque index, modified gingival index, bleeding on probing, and modified sulcular bleeding index, were recorded at implant and adjacent tooth sites. Radiographic assessments using standardized panoramic radiographs and ImageJ® software included marginal bone loss (MBL), vertical distance from the contact point to the alveolar crest (D1), and horizontal implant–tooth distance (D2). Statistical analyses were performed using independent t-tests, Mann–Whitney U-test, and Friedman tests, with P < .05 considered significant.

Results: Ten participants (20%) exhibited newly developed proximal caries adjacent to implants. Marginal bone loss values were highest at the mesial surface of the tooth distal to the implant (2.63 ± 1.97 mm). Although mean MBL, D1, and D2 values were higher in the caries group, intergroup differences were not significant (P > .05). Greater distal D2 distances correlated positively with mesial MBL of distal adjacent teeth, suggesting that excessive horizontal spacing may promote bone resorption and caries.

Conclusion: Deviations from optimal implant–tooth spacing may compromise peri-implant tissue harmony and increase caries susceptibility in adjacent teeth.