Wilson Roberto Sendyk

Comparative, Histological and Histomorphometric Analysis of Three Anorganic Bovine Xenogenous Bone Substitutes: Bio-Oss, Bone-Fill and Gen-Ox Anorganic.

IntroductionAnorganic bovine xenogenous grafts show the best performance as bone substitutes in implantodontics. Bio-Oss is the world’s most widely used and investigated anorganic bone substitute. This article compares two anorganic bovine bone substitutes (Bone-Fill and Gen-Ox anorganic) with Bio-Oss.Materials and MethodsEight New Zealand rabbits were implanted with 4 titanium cylinders randomly filled with Bio-Oss, Bone-Fill, Gen-Ox anorganic or a blood clot. Four animals were sacrificed after 8xa0weeks; 12xa0weeks later, the remaining four were sacrificed. The contents of the cylinders were removed, cut and stained with HE before they were evaluated with an optical microscope. The samples were submitted to histomorphometry for analysis.ResultsThe bone formation with Bio-Oss at 8xa0weeks was 8.43xa0mm2; at 12xa0weeks, it was 9.32xa0mm2. The bone formation with Bone-Fill at 8xa0weeks was 7.24xa0mm2; at 12xa0weeks, it was 9.01xa0mm2. The bone formation with Gen-Ox anorganic at 8xa0weeks was 2.78xa0mm2; at 12xa0weeks, it was 3.02xa0mm2. The bone formation with the blood clot at 8xa0weeks was 0.65xa0mm2; at 12xa0weeks, it was 0.63xa0mm2.ConclusionFollowing this model, Bone-Fill was comparable to Bio-Oss and superior to Gen-Ox and blood clot.

Lateralization Technique and Inferior Alveolar Nerve Transposition

Bone resorption of the posterior mandible can result in diminished bone edge and, therefore, the installation of implants in these regions becomes a challenge, especially in the presence of the mandibular canal and its contents, the inferior alveolar nerve. Several treatment alternatives are suggested: the use of short implants, guided bone regeneration, appositional bone grafting, distraction osteogenesis, inclined implants tangential to the mandibular canal, and the lateralization of the inferior alveolar nerve. The aim was to elucidate the success rate of implants in the lateralization technique and in inferior alveolar nerve transposition and to determine the most effective sensory test. We conclude that the success rate is linked to the possibility of installing implants with long bicortical anchor which favors primary stability and biomechanics.

Vertical Root Fracture: Preservation of the Alveolar Ridge Using Immediate Implants

Teeth with vertical root fracture (VRF) have complete or incomplete fractures that begin in the root and extend toward the occlusal surface. The most frequent causes of VRF originate from physical trauma, occlusal prematurity, inadequate endodontic treatment, and iatrogenic causes. Diagnose is difficult and delay can cause stomatognathic system problem. The purpose of this case report was to evaluate immediate implant placement after extraction of teeth with vertical root fracture. For the 1st case, the VRF in 1st left lower molar was confirmed during surgical flap and at the same time, the tooth was removed and immediate implant was placed. For the 2nd case, the VRF 1st left lower molar was confirmed during endodontic access and at the same appointment, the tooth was removed and the immediate implant is placed. Several studies have shown that immediate implants have similar success rates when compared with late implants. Consider that this approach is a safe procedure with favorable prognosis. In cases of VRF, the main factor to be considered is the presence of adequate bone support and immediate implants can preserve the vertical bone height, adding the fact that good patient compliance reduces the number of surgical interventions and promotes the functionality of stomatognathic system.

Stability of implants placed simultaneously or in a delayed manner on fresh frozen onlay allografts in rabbits.

OBJECTIVESnThis study evaluated the stability of implants installed simultaneously and in a delayed manner in fresh frozen onlay allografts in the tibiae of rabbits.nnnMATERIAL AND METHODSnAnalyses of the resonance frequency (ISQ) and removal torque were performed. The calvarium of three rabbits was used as donor site. Ten New Zealand female rabbits received four allografts of the same dimensions, two in each tibia. The tibiae were randomly allocated into the following two groups: Group 1, the tibiae that received implants after 84 days of healing, and Group 2, those who received the implants simultaneously with the grafts. Both groups were followed for 126 days. Proximal implants in each group were evaluated by resonance frequency (ISQ) on days 0 and 126, and the distal ones with removal torque on day 126.nnnRESULTSnIn both groups, an increase in the ISQ value of day 0-126 was observed, with a statistically significant difference (Group 1 P = 0.049 and Group 2 P = 0.021). When comparing the resonance frequency at day 0 to day 126, and the gain of stability between these days, no statistically significant difference between groups could be observed. The removal torque showed a statistically significant difference between groups 1 and 2 (P = 0.042).nnnCONCLUSIONnThere was an increase in stability in groups according to the analysis of resonance frequency. Implants installed in a delayed manner in allografts showed higher shear force, according to the removal torque analysis.

Bone autografts & allografts placed simultaneously with dental implants in rabbits

OBJECTIVEnThis study compared stability, removal torque, bone implant contact (BIC) and area (BA) of implants installed simultaneously with onlay autografts or allografts in rabbits tibias.nnnMATERIAL AND METHODSnTotal of 18 rabbits were used in this study. Fresh frozen allografts were obtained from six animals at T(-6). Two implants with autogenous grafts (Group 1) or allografts (Group 2) were simultaneously inserted into both sides of the tibiae in a vertical periimplant defect model at T0. The resonance frequency (ISQ) was measured in implant proximal epiphysis on the day of installation of T0 and T18 (18 weeks post-surgery). At T18 the removal torque was assessed at the distal implants, the implants proximal epiphysis and surrounding bone were harvested to perform histomorphometric analysis. The BIC and BA within the limits of the implants threads were evaluated.nnnRESULTSnThe ISQ revealed a statistically significant difference between T0 and T18 in each group (pxa0=xa00.024, pxa0=xa00.003). The removal torque indicates that there was no significant difference between the two groups (pxa0=xa00.47). No significant differences were observed between the groups regarding both BIC (pxa0=xa00.3713) and the BA (pxa0=xa00.3883).nnnCONCLUSIONnBoth grafts and implants demonstrated the same stability, torque removal and the BIC andxa0BA.

Periodontal clinical evaluation before and after surgically assisted rapid maxillary expansion

ABSTRACT Introduction: The surgically assisted rapid maxillary expansion is a procedure that reduces the resistance of the sutures correcting the posterior crossbite in adults. Objective: The aim of this study was to evaluate the periodontal status of 17 adults submitted to this procedure. Methods: The clinical attachment level (CAL), gingival recession, attached gingiva and bleeding were evaluated in maxillary first premolars and molars, central and lateral incisors of right and left sides before surgery, 5 days and 6 months after. Means, standard deviation, medians, minimum and maximum values were compared among the evaluations using the Friedman and McNemar tests. Results: There was a statistically significant increase in CAL in the right central incisor, right and left premolars and right and left molars. There was a statistically significant increase in gingival recession in the right and left premolars and molars. The amount of attached gingiva significantly decreased in right premolars and right and left molars. There was increase in bleeding in most of the teeth. Conclusion: Results indicated that the surgically assisted rapid maxillary expansion might cause alterations in periodontal tissue.