Enamel matrix derivative and bone healing after guided bone regeneration in dehiscence-type defects around implants. A histomorphometric study in dogs

Abstract

Background: 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.

Methods: 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.

Results: 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).

Conclusions: 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.