Bone Assessment in Grafted and Ungrafted Sockets After Dental Implant Placement: A 10-year Follow-up Study

The purpose of this study was to compare success and outcomes among implants positioned either in grafted or ungrafted alveoli during 10 years of follow-up.

This retrospective analysis was conducted on data of subjects who underwent tooth extraction and alveolar ridge preservation. Sites, one per patient, were ranked into three groups: postextraction ungrafted alveoli, and postextraction grafted alveoli with either synthetic magnesium-enriched hydroxyapatite or porcine bone. An absorbable collagen sheet was used to completely cover all the sockets. A secondary intention healing was sought for all procedures. Data regarding implant survival and marginal bone loss around implants were gathered until the 10-year follow up. Pairwise comparisons were performed with nonparametric tests, and statistical significance was set at .01.

Sixty-three subjects were included: 42 implants (19 and 23 in the magnesium-enriched hydroxyapatite and porcine bone groups, respectively) placed in grafted sites and 21 in nongrafted sites. The success rate of the grafted groups was 88.1% (CI: 78.3% to 97.9%) at the 10-year follow-up. On the other hand, in the ungrafted group, the overall success rate was 85.7% (CI: 70.8% to 100%). Peri-implant marginal bone loss at the 10-year follow-up for the magnesium-enriched hydroxyapatite group was 1.2 (0.7) mm, while for the porcine bone group, it was close to 0. The behavior of the ungrafted group appeared to be significantly different compared with both grafted groups; however, marginal bone levels ranging from 0.1 to 0.4 mm were observed from 3 to 10 years.

A difference in terms of long-term success rates between grafted and ungrafted sites was not revealed. Bone loss was significantly higher in the magnesium-enriched hydroxyapatite grafted group compared with those in the other groups (without or with other bone substitute material).