AUTOGENOUS BLOCK ONLAY BONE GRAFT VERSUS XENOGENIC CORTICAL BONE LAMINA IN ALVEOLAR RIDGE AUGMENTATION: A CLINICAL, RADIOGRAPHIC AND HISTOLOGICAL EVALUATION

Abstract

The present study was conducted on fourteen patients randomly divided into two equal groups to compare between autogenous block onlay bone graft and xenogenic cortical bone lamina in alveolar ridge augmentation. All patients had a maxillary partially edentulous ridge which required horizontal width augmentation labiolingually prior to implant placement. Two surgeries were carried out for each patient; the first surgery was for alveolar ridge augmentation (bone grafting) while the second surgery was for implant placement in a routine fashion. Alveolar ridge augmentation was performed in group one using intraoral autogenous onlay block bone graft harvested from the mandibular symphysis using piezoelectric surgery, while in group two alveolar ridge augmentation was performed using xenogenic soft cortical bone lamina. Implant placement was performed six months after the ridge augmentation surgery. A trephine bur was used to obtain bone biopsy at the implant site before preparation of the implant recipient bed for histological examination. Three months after placement of the implant, prosthetic procedures were performed. The alveolar ridge buccolingual (BL) horizontal width was measured before and after the augmentation procedures clinically by using the bone caliper and radiographically by using the cone beam computed tomography. In both groups clinically; there was a statistically significant increase in BL ridge width immediately after graft placement. Then a statistically significant decrease in mean BL ridge width was observed after 6 months compared to the width after graft fixation. From 6 months to 9 months as well as from 9 months to 12 months; there was no statistically significant change in mean clinical BL ridge width. 6, 9 as well as 12 months periods showed statistically significantly higher mean BL ridge width than baseline measurement. Through the whole study period, there was no statistically significant difference between mean % changes in clinical BL ridge widths in the two groups.

In both groups radiographically; there was a statistically significant increase in BL ridge width after 6 months. From 6 months to 12 months; there was no statistically significant change in mean BL ridge width. 12 months period showed statistically significantly higher mean BL ridge width than base line measurement. Through the whole study period, there was no statistically significant difference between mean % changes in radiographic BL ridge widths in the two groups. Histomorphometric and histologic analysis showed that there was no statistically significant difference between mean bone surface areas in the two groups. There was no statistically significant difference between mean osteoblasts counts in the two groups. On histologic examination of the augmented sites in both groups, newly formed bone, both woven and more mature lamellar bone were observed in all sites in both groups. In conclusion, the results showed that the cortical bone lamina used in the present study can be safely and successfully used in horizontal alveolar ridge augmentation as an alternative to the intraoral autogenous block onlay bone graft.