[Dimensional ridge alterations following tooth extraction. An experimental study in the dog]

The aim of the present study was to histologically evaluate extraction wound healing after socket preservation using a beta-TCP root taper.Ten dogs were used in the study. Immediately following careful extraction of the first premolar of the lower jaw the extraction sockets were filled using a chair-side thermically formed polylactide-linked root taper (RT). To avoid contamination, a further polylactide barrier covered the crestal surface of the taper. Untreated extraction sites of the opposite side served as control. After three and six months of healing, the animals were sacrified and dissected blocks were prepared for histomorphometrical analysis. Following parameters were evaluated: difference between lingual and buccal bone height, lingual and buccal alveolar wall and total bone width 1, 3 and 5mm underneath the top of the respective crest. During the entire study period healing was uneventful for all animals. Histological analysis of three months specimens revealed a definable area of minor mineralized bone within the former extraction sockets in both RT and control group. In the test group small areas of material organized by connective tissue but no remnants of the bone substitute material could be observed. After six months the borderline between new and pre-existing bone had disappeared. Histomorphometric analysis revealed no statistically significant differences between test and control group after three or six months (p>0.05, paired T-test). Within the limits of the present study it was concluded that the application of polylactide-stabilized RT does not improve the dimensional ridge alterations after tooth extraction.