Evaluation of bone loss at single-stage and two-stage implant abutments of fixed partial dentures.

INTRODUCTION Fixed partial dentures (FPDs) can be supported on implant abutments only or on single-stage and two-stage implants and teeth. PURPOSE The purpose of this study was a comparative analysis of bone loss at the single-stage and two-stage implant abutments of fixed partial dentures used to restore missing teeth classified as Class I or Class II according to the Kennedy classification. MATERIAL AND METHODS 32 patients were treated by using 49 FPDs supported on implants and teeth worn for 2-6 years. Bone loss at the implant abutments of FPDs was evaluated by one examiner using a special ruler with a measuring scale and images of implants. Measurements were conducted at 26 single-stage implants and 50 two-stage implant abutments based on panoramic radiographs. RESULTS Statistical analysis showed that the mean bone loss at implants after 2 years was 0.70 mm +/- 0.50. The mean bone loss at implants after 6 years was 1.73 mm +/- 0.41. The bone loss of the alveolar ridge at the single-stage implants was greater than at the two-stage implants but it was not statistically significant. CONCLUSION Prosthetic treatment of missing teeth classified as Class I or II according to the Kennedy classification with FPDs may result in bone loss less than 2 mm after 6 years. Both single-stage and two-stage intraosseous implants can be suitable for the implant-prosthetic treatment of patients with alar lack of teeth.