Reconstruction of alveolar bone defects after extraction of mandibular third molars: a pilot study

A documented complication of mandibular third molar extraction is the development of bony defects on the distal aspect of the adjacent second molar. The primary study purpose was to determine the efficacy of grafting third molar extraction sites with demineralized bone powder to prevent the formation of periodontal defects.

With a randomized clinical trial study design and a third molar extraction surgical model, we enrolled a study sample composed of patients who required extraction of bilateral third molars. Demineralized bone powder was placed in one randomly selected extraction site per patient. The remaining extraction site served as a control. Patients served as their own controls. To assess periodontal healing, we measured plaque and gingival indexes and periodontal attachment loss on the distobuccal aspect of the adjacent second molar preoperatively and 6 months postoperatively.

Of 14 patients enrolled, 7 patients with a mean age of 21.7 +/- 3.7 years completed the study protocol. No statistically significant differences were noted between patients who did and did not complete the study protocol (all p values > or = 0.42). There were noted statistically significant differences for the various anatomic, operative, or periodontal measures between the control and treatment teeth preoperatively (all p values > or = 0.46). Six months postoperatively, there were no statistically significant changes in the plaque or gingival indexes for the control or experimental sites. At the control sites, there was a nonstatistically significant decrease in mean attachment loss from 3.1 +/- 1.3 mm preoperatively to 1.4 +/- 1.6 mm 6 months postoperatively (p = 0.06). At experimental sites, there was a statistically significant decrease in mean attachment loss from 3.3 +/- 1.4 mm preoperatively to 0.6 +/- 0.8 mm 6 months postoperatively (p = 0.02)

The study results suggest that demineralized bone powder may decrease attachment loss on the distal aspect of the second molar after extraction of the adjacent third molar. Additional studies are indicated to confirm the results of this pilot study. We recommend that future studies limit their study samples to patients at high risk for developing periodontal defects after third molar extraction.