Enamel Matrix Derivative And Bone Healing After Guided Bone Regeneration In Dehiscence-type Defects Around Implants. A Histomorphometric Study In Dogs.

Abstract

The goal of this investigation was to histometrically evaluate the effect of enamel matrix derivative (EMD) on bone healing after guided bone regeneration (GBR) in dehiscence-type osseous defects around dental implants; i.e., in the absence of periodontal ligament cells. Six mongrel dogs were used. The second, third, and fourth mandibular premolars (p2, p3, and p4) and first molars (ml) were extracted. After 3 months, 2 implant osteotomies were prepared in each side of the mandible, dehiscence-type defects were created on the buccal aspect of each implant osteotomy (3.5 mm x 5.0 mm), and titanium implants were placed (3.75 mm x 8.5 mm). The surgically-created defects were randomly assigned to one of the treatments: EMD, GBR, EMD+GBR, or control. After 2 months, 4 additional defects were created and treated. The animals were sacrificed 3 months after the placement of the first implants, thus allowing the healing periods of 1 and 3 months. Undecalcified sections were obtained for the histometric evaluation including the percentage of bone-to-implant contact and new bone area on the implant threads related to the defect. No statistically significant differences were observed among the groups in the evaluated parameters after 1 month of healing. After 3 months, no statistically significant differences were observed among the groups for the percentage of bone-to-implant contact. The values for the new bone area were: 55.5+/-11.8, 53.8+/-16.3, 62.1+/-18.4, and 36.9+/-25.1 for EMD, GBR, EMD+GBR, and control, respectively. The difference between EMD+GBR and control was statistically significant (P <0.05). Within the limits of this study, it can be concluded that EMD may positively influence bone healing after GBR around titanium implants. EMD alone, however, had no statistically significant effect.