Efficacy of using a dual layer of membrane (dPTFE placed over collagen) for ridge preservation in fresh extraction sites: a micro-computed tomographic study in dogs.

OBJECTIVE To assess if overbuilding the buccal plate or using a dual-layer socket grafting technique prevents alveolar bone resorption and enhances final ridge width, height, and volume after tooth loss in an animal model. MATERIAL AND METHODS In eight beagle dogs bilateral second (P2)-, third (P3)-, and fourth (P4) premolars were endodontically treated. All bilateral mandibular first premolars and distal roots of P2, P3, and P4 were hemisectioned and atraumatically extracted. Animals were randomly divided into four groups: (i) Control-Socket alone, (ii) Particulate allograft in the alveolum, socket covered with high-density polytetrafluoroethylene (dPTFE) membrane and sutured over the alveolum, (iii) Particulate allograft in the alveolum and overbuilding the buccal plate, socket covered with dPTFE membrane and sutured over the alveolum, (iv) Particulate allograft in the alveolum and covered with dual layer (dPTFE placed over collagen membrane), and sutured over the alveolum. After 16 weeks, the animals were sacrificed. Mandibular blocks of the jaws were assessed for bone volume (BV), vertical bone height (VBH), alveolar ridge thickness, and bone mineral density (BMD) using micro-computed tomography. RESULTS The BV in groups 1, 2, 3, and 4 was 169.5, 207.57, 242.4, and 306.1 mm(3) , respectively. The VBH in groups 1, 2, 3, and 4 was 4.2, 6.4, 6.2, and 7.3 mm, respectively. Ridge widths in groups 1, 2, 3, and 4 were 5.45 ± 0.75, 5.91 ± 0.86, 6.05 ± 0.63, and 6.28 ± 1.01 mm, respectively. There was no significant difference in BMD between the groups. CONCLUSIONS The RP using a dual layer of membrane following tooth extraction results in more BV, VBH, and alveolar ridge width as compared to when a single layer of membrane is used.