Comparative Evaluation of Bone Repair with Four Different Bone Substitutes in Critical Size Defects.

This study evaluated the osteoconductive potential of four biomaterials used to fill bone defects. For this, 24 male Albino rabbits were submitted to the creation of a bilateral 8 mm calvarial bone defect. The animals were divided into four groups-bovine hydroxyapatite, Bio-Oss® (BIO); Lumina-Bone Porous® (LBP); Bonefill® (BFL); and an alloplastic material, Clonos® (CLN)-and were euthanized at 14 and 40 days. The samples were subjected to histological and histometric analysis for newly formed bone area. Immunohistochemical analysis for Runt-related transcription factor 2 (Runx2), vascular endothelial growth factor (VEGF), and osteocalcin (OC) was performed. After statistical analysis, the CLN group showed greater new bone formation (NB) in both periods analyzed (p < 0.05). At 14 days, the NB showed greater values in BIO in relation to LBP and BFL groups; however, after 40 days, the LBP group surpassed the results of BIO (p < 0.001). The immunostaining showed a decrease in Runx2 intensity in BIO after 40 days, while it increased for LBP (p < 0.05). The CLN showed increased OC compared to the other groups in both periods analyzed (p < 0.05). Therefore, CLN showed the best osteoconductive behavior in critical defects in rabbit calvaria, and BFL showed the lowest osteoconductive property.

Dental Implants Can Facilitate Orthognathic Surgery in a Patient With Severe Maxillary Atrophy.

The surgical treatment of dentofacial deformities is performed routinely and predictably in dentate patients. However, when dealing with the edentulous maxilla, treatment becomes more challenging and less predictable. In these cases, the combination of orthognathic surgery and osseointegrated implants could be a viable alternative to enable fixed rehabilitation. A patient with an edentulous and atrophic maxilla with maxillomandibular discrepancy and high esthetic requirement was treated with a combination of osseointegrated implants and orthognathic surgery. The rehabilitative sequence was composed of maxillary grafting procedures, installation of dental implants, placement of a fixed implant-supported prosthesis, and bimaxillary orthognathic surgery. During provisional restoration before orthognathic surgery, smaller teeth were used, allowing achievement of appropriate tooth length for the final restoration, even after natural and expected postoperative relapse. This restorative approach provided an implant-supported fixed prosthesis without prosthetic compensation and with optimum esthetics and biomechanics.

Influence of implant drill materials on wear, deformation, and roughness after repeated drilling and sterilization.

PURPOSE: The aim of this study was to evaluate deformation, roughness, and mass loss of stainless steel, diamond-like carbon (DLC)-coated and zirconia drills after multiple osteotomies with sterilization procedures. MATERIALS AND METHODS: Drilling procedures were performed using stainless steel (G1), DLC-coated (G2), and zirconia (G3) drills. All groups were divided in subgroups 1, 2, 3, 4, and 5, corresponded to drills used 0, 10, 20, 30, and 40 times, respectively. RESULTS: No significant differences in mass and roughness were detected among all groups and subgroups. In SEM images, all groups revealed signs of wear while coating delamination was detected in G2. Drills from G1 displayed more irregular surface, whereas cutting edges were more regular in G3. CONCLUSION: Zirconia drills presented more regular surfaces whereas stainless steel drills revealed more severe signs of wear. Further studies must be performed to evaluate the putative influence of these findings in heat generation.