Alveolar ridge regeneration with equine spongy bone: a clinical, histological, and immunohistochemical case series.

BACKGROUND In the case of localized ridge atrophy, a ridge augmentation procedure, with the use of bone substitutes and barrier membranes, may then be necessary. PURPOSE The aim of the present study was a clinical, histological, and immunohistochemical evaluation of an equine spongy bone in alveolar ridge augmentation procedures. MATERIALS AND METHODS Five patients showing horizontal mandibular ridge defects participated in this study. A ridge augmentation was performed through an onlay apposition of equine bone covered by a titanium-reinforced membrane. After 6 months of healing, five bone cores from nonaugmented sites (control) and five from augmented sites (test) were retrieved. RESULTS In test sites, no postoperative complications occurred. Horizontal bone width increased from 24 to 37 mm. In control sites, the newly formed bone represented 33%, and in test sites, 35% of the total area. The mean value of the microvessel density was 25.6 +/- 3.425 per mm(2) in controls, while 33.3 +/- 2.5 vessels per mm(2) in the test sites were found (p < .05). Both groups showed a high intensity (++) of vascular endothelial growth factor expression in the newly formed bone, while a low intensity (+) was found in the mature bone. CONCLUSION Equine bone appeared to be biocompatible and to be associated with new vessel ingrowth. Within the limits of the small sample size, the present study indicated that equine bone could be used in mandibular ridge augmentations.