Flaviana Soares Rocha

Retrospective study of bone grafting procedures before implant placement.

Aim:The aim of this retrospective study was to evaluate morbidity and possible complications in augmentation procedures before implant placement. Methods:Records from 93 consecutive patients with indication for autogenous bone grafting before implant placement, treated at Department of Oral and Maxillofacial Surgery and Implantology of Uberlândia Federal University, in a 7-year period (July 2000 until July 2007), were reviewed. The need for bone grafting was defined by the impossibility of installing implants of adequate length or diameter to fulfill prosthetic requirements or for aesthetic reasons. Results:A total of 136 bone grafting procedures were performed. The mandibular external oblique line and ascending ramus were the most frequently used donor areas (59.64%) and block grafts (67.64%) were the most frequently used type of graft, frequently from the mandibular external oblique line/ascending ramus (52.18%). Platelet-rich plasma was used in 20.1% of all procedures, usually associated with particulate bone grafts. Maxillary procedures represented the majority of surgeries (75%), but with fewer complications compared with the mandible. Sinus mucosa perforation was the most frequent complication in maxillary procedures, whereas graft exposure was the most common complication in mandible. Conclusions:Alveolar reconstruction using autogenous bone followed by implant placement is a reliable treatment for patients with insufficient bone. Complications and morbidity were frequently observed. However, in only 6.6% of all procedures, the final rehabilitation with dental implants was not possible.

Saliva versus peri-implant inflammation: quantification of IL-1β in partially and totally edentulous patients.

The aim of this study was to investigate the potential use of salivary IL1β in early-stage diagnostics of peri-implant inflammation in partially and totally edentulous patients rehabilitated with dental implants. Patients were classified according to peri-implant probing depth and bleeding upon probing in groups of healthy individuals or in groups of individuals with peri-implant inflammation. Data on plaque index, clinical attachment loss, suppuration, and mobility were also assessed. Saliva was collected without stimulation, and the levels of IL-1β were determined by ELISA. Healthy groups demonstrated significantly lower levels of IL-1β compared with the inflammation groups. No difference in IL-1β levels was observed between partially edentulous or totally edentulous patients. Salivary IL-1β may be useful for the diagnosis and monitoring of early peri-implant inflammation, particularly in edentulous patients.

Bovine Anorganic Bone Graft Associated with Platelet-Rich Plasma: Histologic Analysis in Rabbit Calvaria

Autogenous bone tissue has regeneration potential; however, this capacity may not be sufficient in larger bone defects. The aim of this study is to histologically evaluate anorganic bovine bone grafts (GenOx Inorg) with or without platelet-rich plasma (PRP). Two bone lesions were created in calvaria of 12 rabbits. The 24 surgical lesions were separated into 3 groups: coagulous, anorganic, and anorganic with PRP. At the 4-week time point, the animals were euthanized and the grafted area removed, fixed in formalin 10% with phosphate buffered saline, 0.1 M, and embedded in paraffin. The histologic parameters analyzed were new bone filling the defect area, presence of giant cells and particles of the graft, and new bone formation associated with the particles. In the coagulous group, defects were filled with fibrous tissue that attached the periosteum and little bone neoformation in the periphery. In anorganic groups with or without PRP, little new bone formation in the periphery of the defect was observed; however, in the center of some defects there was new bone. Moderate presence of giant cells and little new bone formation was associated with the innumerous graft particles. Histologic results revealed no statistically significant differences among the defects new bone fill between the studied groups (P = .64). There was no significant difference in the number of giant cells (P = .60), graft particles (P = .46), and new bone formation around graft particles (P = .26), whether PRP was added or not. Anorganic bone, isolated or mixed with PRP, was biocompatible and osteoconductive, while maintaining bone volume.

Enxerto bovino orgânico associado ao PRP em calvária de coelhos

INTRODUCTION: The osseous repairing in big imperfections is a great challenge for the restored surgery in nowadays. OBJECTIVE: The objective of this study was to make an histological evaluation of the osseous restore in rabbits calvaria after the bovine osseous grafts (Gen-ox-organic®) usage associated with plasma rich in platelet (PRP). METHOD: It was used 12 rabbits and 02 osseous fragments were removed from bilaterally calvarium. So among 24 surgical sites were randomly, divided in 03 groups: coagulum (group I), organic (group II) and organic with PRP (group III). After 04 weeks the animals were sacrificied and the grafted area was removed, fixed in formaldehyde at 10% in PBS 0,1M and included in paraffin. RESULTS: The histologic parameters analysed were: imperfection area filled up with neoformed, gigantic cells and grafts particles, and osseous neoformation associated with the particles. The groups I imperfections were filled up with fibrous tissue that conditioned the periosteum and presented a small osseous formation in the perimeter. In groups II and III, a similar pattern was observed and also with grafts particles and gigantic cells absence. There was no significative difference in gigantic cells, grafts particles and neoformations numbers around the particles between the grafted material and the group with PRP associated. CONCLUSION: The obtained results show that the isolated organic biomaterial or in association with PRP did not improve the osseous regeneration.

The Effect of Local Delivery Doxycycline and Alendronate on Bone Repair

The aim of the present study was to investigate the local effect of 10% doxycycline and 1% alendronate combined with poly(lactic-co-glycolic acid) (PLGA) on bone repair. Thirty rats were divided into three groups, as follows: control group (CG), drug group (DG), and vehicle-PLGA group (VG). Bone defect was created in the right femur and filled with the following: blood clot (CG); PLGA gel, 10% doxycycline and 1% alendronate (DG); or vehicle-PLGA (VG). The animals were euthanized 7 or 15 days after surgery. Bone density, bone matrix and number of osteoclasts were quantified. At 7 days, the findings showed increased density in DG (177.75 ± 76.5) compared with CG (80.37 ± 27.4), but no difference compared with VG (147.1 ± 41.5); no statistical difference in bone neoformation CG (25.6 ± 4.8), VG (27.8 ± 4), and DG (18.9 ± 7.8); and decrease osteoclasts in DG (4.6 ± 1.9) compared with CG (26.7 ± 7.4) and VG (17.3 ± 2.7). At 15 days, DG (405.1 ± 63.1) presented higher density than CG (213.2 ± 60.9) and VG (283.4 ± 85.8); there was a significant increase in percentage of bone neoformation in DG (31.5 ± 4.2) compared with CG (23 ± 4), but no difference compared with VG (25.1 ± 2.9). There was a decreased number of osteoclasts in DG (20.7 ± 4.7) and VG (29.5 ± 5.4) compared with CG (40 ± 9.4). The results suggest that the association of 10% doxycycline and 1% alendronate with PLGA-accelerated bone repair.

Influence of Implant Surfaces on Osseointegration: A Histomorphometric and Implant Stability Study in Rabbits.

The aim of this study was to evaluate the stability and osseointegration of implant with different wettability using resonance frequency analysis (RFA) and histomorphometric analysis (bone implant contact, BIC; and bone area fraction occupied, BAFO) after 2 and 4 weeks in rabbit tibiae. Thirty-two Morse taper implants (length 7 mm, diameter 3.5 mm) were divided according to surface characteristics (n=8): Neo, sandblasted and dual acid-etched; and Aq, sandblasted followed by dual acid-etched and maintained in an isotonic solution of 0.9% sodium chloride. Sixteen New Zealand rabbits were used. Two implants of each group were installed in the right and left tibiae according to the experimental periods. The RFA (Ostell(r)) was obtained immediately and after the sacrifice (2 and 4 weeks). The bone/implant blocks were processed for histomorphometric analysis. Data were analyzed using two-way ANOVA followed by Tukeys test and Pearsons correlation for ISQ, BIC and BAFO parameters (p=0.05). No significant effect of implant, period of evaluation or interaction between implant and period of evaluation was found for BIC and BAFO values (p>0.05). Only period of evaluation had significant effect for RFA values at 4 weeks (p=0.001), and at 2 weeks (p<0.001). RFA values were significantly higher at the final period of evaluation compared with those obtained at early periods. There was a significant correlation between BIC values and BAFO values (p=0.009). Both implant surfaces, Aq and Neo, were able to produce similar implant bone integration when normal cortical bone instrumentation was performed.

The approach of ameloblastoma of the mandible: a case treated by hyperbaric oxygen therapy and bone graft reconstruction

BackgroundReconstruction of mandibular defects after tumor resection is a challenge to the head and neck surgeon because of associated functional and esthetic problems. The intention of mandibular reconstructive surgery is to achieve maximum possible functionality, which means the restoration of masticatory function and speech with a good esthetic result. Hyperbaric oxygen therapy (HBO) is already a well-accepted adjunct in the treatment of extensive bone defects. It has been shown to enhance osteogenesis and improve soft tissue wound healing in a variety of circumstances.Case reportThe following case report describes a 29-year-old woman who was diagnosed with mandibular ameloblastoma. The treatment of choice is resection with mandibular base maintenance. The patient underwent 10 sessions of hyperbaric oxygen therapy and subsequent nonvascularized iliac crest graft. Six months after, mandibular reconstruction is possible to observe the preservation of mandibular contouring and facial esthetics. A panoramic radiograph revealed good positioning of the bone graft and volume maintenance.DiscussionThe mandibular reconstruction is extremely important for the rehabilitation of the patient who underwent bone resection. The restoration of mandibular function and facial esthetics is essential to maintain the quality of life. The use of HBO in mandibular reconstruction is an important adjunct to successful treatment, however, more studies are needed to establish the best modalities of rehabilitation.

Influence of hyperbaric oxygen on the initial stages of bone healing

OBJECTIVE The objective of this study was to evaluate, in a rat model, the effect of hyperbaric oxygen (HBO) on the healing of normal bone on day 7. STUDY DESIGN Forty male rats were used, equally divided into two groups based on treatment and time of sacrifice: the control group had bone defects created; and the HBO group had bone defects and received HBO. HBO sessions were conducted daily, at 2.5 atmosphere absolute for 90 minutes, and the animals were euthanized after 1, 3, 5, or 7 days. Bone density, bone neoformation, and expression of Runt-related transcription factor 2 (Runx2) and tartrate-resistant acid phosphatase were evaluated. RESULTS Computed tomography analysis revealed significant differences only at 3 days (P=.01) between the control and HBO groups. HBO treatment accelerated the initial events of bone repair, resulting in improved bone neoformation. Increased expression of Runx2 was observed, especially on days 5 and 7 in the HBO group, although not significantly. There was no significant difference (P=.74) in the number of tartrate-resistant acid phosphatase-positive osteoclasts between the control and HBO groups on day 7. CONCLUSIONS These results suggest that exposure to HBO enhances bone anabolism, reduces inflammation, and accelerates bone healing, with positive results in bone neoformation. Therefore, the aim of this study was to evaluate the effect of HBO on the healing of experimental defects created in normal bone, on the first 7 days, in a rat model.

Effect of Different Storage Media on the Regenerative Potential of Autogenous Bone Grafts: A Histomorphometrical Analysis in Rabbits

The success of autogenous bone graft is related to the graft cell viability. In bone-grafting procedures, harvested grafts are often maintained in extraoral media while the recipient site is prepared. The aim of this study was to evaluate in vivo the effect of storage media over autogenous bone grafts during the transsurgical time. Two grafts were removed bilaterally from the calvaria of 18 rabbits. One graft was immediately fixed in the mandibular angle (control group), and the other was maintained in air exposure (dry group), 0.9% NaCl solution (saline group), or platelet-poor plasma (PPP group) during 30 minutes and stabilized in the symmetrical location of control grafts. After 28 days, the animals were euthanized and the bone fragments were removed, demineralized, and embedded in paraffin. Histological evaluation was performed under light microscope. Empty lacunae and bone graft area quantification were carried out for the sections. The histomorphometrical analysis revealed reduction of the graft area and increase of empty lacunae in the dry group when compared with control. No significant differences were found in the number of empty lacunae or bone graft area between the saline group and its control and also between the PPP group and its control. The dry group showed more empty lacunae and less graft area than the saline and PPP groups. In accordance with the results, PPP and physiologic solution demonstrated osteocyte preservation and bone graft area maintenance, being satisfactory storage media for autogenous bone grafts during the transsurgical period.

High doses of ionizing radiation on bone repair: is there effect outside the irradiated site?

Local ionizing radiation causes damage to bone metabolism, it reduces blood supply and cellularity over time. Recent studies indicate that radiation promotes biological response outside the treatment field. The aim of this study was to investigate the effects of ionizing radiation on bone repair outside the irradiated field. Ten healthy male Wistar rats were used; and five animals were submitted to radiotherapy on the left femur. After 4 weeks, in all animals were created bone defects in the right and left femurs. Seven days after surgery, animals were euthanized. The femurs were removed and randomly divided into 3 groups (n=5): Control (C) (right femur of the non-irradiated animals); Local ionizing radiation (IR) (left femur of the irradiated animals); Contralateral ionizing radiation (CIR) (right femur of the irradiated animals). The femurs were processed and embedded in paraffin; and bone histologic sections were evaluated to quantify the bone neoformation. Histomorphometric analysis showed that there was no significant difference between groups C (24.6±7.04) and CIR (25.3±4.31); and IR group not showed bone neoformation. The results suggest that ionizing radiation affects bone repair, but does not interfere in bone repair distant from the primary irradiated site.