Early healing of the alveolar process after tooth extraction: an experimental study in the beagle dog

Aim To describe the early healing events in the alveolar socket during the first 8weeks of spontaneous healing after tooth extraction. Materials and Methods 16 adult beagle dogs were selected and five healing periods were analysed (4h, 1week, 2weeks, 4weeks, 8weeks). Mandibular premolars were extracted and each socket corresponding to the mesial root was left to heal undisturbed. In each healing period, three animals were euthanatized, each providing four study sites. Healing was assessed by descriptive histology and by histometric analysis using as landmarks: the vertical distance between buccal and lingual crest (B'L') and the width of buccal and lingual walls at three different levels. Differences between means for each variable for each healing period were compared (ANOVA; p<0.05). Results B'L' at baseline was 0.45 (0.18) mm and decreased during the healing period to a final value of 0.18 (0.08) mm. The lingual width (Lw) remains almost unchanged while the buccal width (Bw) at 1 (Bw1) and 2 (Bw2) mm was reduced in about 40% of its initial value. Conclusions Minor vertical bone reduction in both the buccal and lingual socket walls were observed. A marked horizontal reduction of the buccal bone wall was observed mostly in its coronal aspect.