Three-Dimensional Evaluation of Alveolar Bone Levels Around Dental Implants and Natural Teeth: A Prospective Study

Dental implants' efficacy is influenced by the quality and quantity of the osseous tissue present at the site designated for dental implants. Therefore, this study was conducted with the primary objective of assessing marginal bone loss around mandibular posterior dental implants at six and 18 months after prosthesis placement, compared with the contralateral natural tooth. The secondary objective was to determine the correlation between various factors such as periodontal status, age, gender, duration between first and second-stage surgery, and marginal bone loss.

This prospective, split-mouth study was conducted on 24 patients, consisting of two groups: group 1, with single tooth replacement by a dental implant in the posterior mandible, and group 2, a contralateral natural tooth. The bleeding index (BI), probing depth (PD), and marginal bone loss were evaluated using cone-beam computed tomography at six and 18 months follow-up period after prosthesis placement.

Significant bone loss was observed in both groups across all regions (p < 0.05). The mean marginal bone loss was greater at 18 months in group 1 than at six months of follow-up, whereas in group 2, it was not significant. The total mean marginal bone loss during the follow-up period of 18 months was 0.05 mm on the buccal and lingual side, whereas it was 0.5 mm on the mesial side and 2 mm on the distal side. Similarly, in the control group, the total mean marginal bone loss was 0.03 mm on the buccal and lingual sides, whereas it was 0.04 mm on the mesial and distal sides. The PD and duration of second-stage surgery were significant predictors and showed a significant correlation with marginal bone loss.

PD and marginal bone loss were significantly higher in the implant group than in the natural tooth group over the follow-up period of 18 months, particularly on the distal side.