Quantitative analysis of radiological changes in alveolar bone around connected osseo-integrated dental implants and natural abutment teeth

Objective: To evaluate quantitatively the long-term changes in alveolar bone around tooth-implant connections using a digital subtraction technique. Study design: Eighteen cases where implants were embedded and connected to the mandibular molar teeth or to each other were analyzed. Digital subtraction images were obtained from baseline and follow-up digitized radiographs. These images were quantitatively analyzed by two methods, "area analysis" and "density analysis". Calcification and decalcification around the abutment teeth and implants were quantitatively evaluated. In two cases involving abutment teeth with a considerable loss of supporting periodontal tissues, the treatment process used was thoroughly evaluated to study how alveolar bone regeneration occurs in such patients. Results: No decalcification areas were detected in any of the cases. Calcification around abutment teeth, implants, or both was observed in 11 (92%) of 12 cases. In the remaining 6 cases, in which implants were connected to each other, calcification was observed around the implants in 4 cases (67%). In two cases where long-term quantitative analysis was possible, calcification started 4 years after placement of connected crowns. Conclusion: Connection of osseo-integrated implants to abutment teeth may be an effective treatment for patients suffering from periodontal disease.