Estudo da compatibilidade de atemoia ((Annona cherimola Mill. X Annona squamosa L. CV. 'THOMOSON') enxertada em araticum-de-terra-fria [Annona emarginata (Schltdl.) H. Rainer variedade terra-fria] e biribá [[Annona mucosa (Bai.) H. Rainer]

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Periodontal disease-associated compensatory expression of osteoprotegerin is lost in type 1 diabetes mellitus and correlates with alveolar bone destruction by regulating osteoclastogenesis

Alveolar bone resorption results from the inflammatory response to periodontal pathogens. Systemic diseases that affect the host response, such as type 1 diabetes mellitus (DM1), can potentiate the severity of periodontal disease (PD) and accelerate bone resorption. However, the biological mechanisms by which DM1 modulates PD are not fully understood. The aim of this study was to determine the influence of DM1 on alveolar bone resorption and to evaluate the role of receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin (OPG) in osteoclastogenesis in rats. PD was induced by means of ligature in nondiabetic and in streptozotocyn-induced DM1 rats. Morphological and morphometric analyses, stereology and osteoclast counting were performed. RANKL and OPG mRNA levels, protein content, and location were determined. PD caused alveolar bone resorption, increased the number of osteoclasts in the alveolar bone crest and also promoted changes in RANKL/OPG mRNA expression. DM1 alone showed alveolar bone destruction and an increased number of osteoclasts at the periapical and furcal regions. DM1 exacerbated these characteristics, with a greater impact on bone structure, resulting in a low OPG content and a higher RANKL/OPG ratio, which correlated with prominent osteoclastogenesis. This work demonstrates that the effects of PD and DM1 enhance bone destruction, confirms the importance of the RANKL signaling pathway in bone destruction in DM1 in animal models and suggests the existence of alternative mechanisms potentiating bone degradation in PD.

Alveolar ridge and maxillary sinus augmentation using rhBMP-2: a systematic review

Purpose: The aim of this systematic review was to evaluate clinical and safety data for recombinant human bone morpho-genetic protein-2 (rhBMP-2) in an absorbable collagen sponge (ACS) carrier when used for alveolar ridge/maxillary sinusaugmentation in humans.Materials and Methods: Clinical studies/case ser ies published 1980 through June 2012 using rhBMP-2/ACS were searched.Studies meeting the following criteria were considered eligible for inclusion: >10 subjects at baseline and maxillary sinus oralveolar ridge augmentation not concomitant with implant placement.Results: Seven of 69 publications were eligible for review. rhBMP-2/ACS yielded clinically meaningful bone formationfor maxillary sinus augmentation that would allow placement of regular dental implants without consistent differencesbetween rhBMP-2 concentrations. Never theless, the statistical analysis showed that sinus augmentation following autog-enous bone graft was significantly greater (mean bone height: 1.6 mm, 95% CI: 0.5–2.7 mm) than for rhBMP-2/ACS(rhBMP-2 at 1.5 mg/mL). In extraction sockets, rhBMP-2/ACS maintained alveolar ridge height while enhancing alve olarridge width. Safety reports did not represent concerns for the proposed indications.Conclusions: rhBMP-2/ACS appears a promising alternative to autogenous bone grafts for alveolar ridge/maxillary sinusaugmentation; dose and carrier optimization may expand its efficacy, use, and clinical application.

Osteotomia sagital da crista alveolar para instalação de implantes Bicon

This case report presents details of a new surgical technique for mandibular ridge sagittal osteotomy and expansion associated to immediate dental implants in atrophic ridges. The bone atrophies represents a challenge for the surgeons that intends to modify this situation. In the past, the only viable option was the onlay bone graft. However, the bone graft requests a second surgical site that certainly increases the postoperative morbidity, without mentioning the longer treatment time required. The sagittal osteotomy of the alveolar crest represents a faster option, because it eliminates the time requested for bone graft integration, providing rehabilitation of edentulous areas with thin alveolar crests that otherwise would need additi onal surgical procedures for a satisfactory result. The authors report a clinical case in which this technique was used with the installation of a Bicon dental implant in the same surgical time, showing all the steps for this single-tooth rehabilitation.

Dynamic functional impression technique fo severely resorbed alveolar ridges

The process of bone resorption can reduce the volume of the alveolar crest, which makes may make difficult impression taking of the alveolar tissue and the subsequent fit of a new denture. This clinical report describes a fast and simple technique for impressions of edentulous ridges to replace complete dentures, using a temporary tissue conditioner material on the denture base. The existing denture must cover the whole supporting area and should be in harmony with the adjacent oral structures. This technique reduces the number of steps involved and minimizes treatment time and expenses.

Estudio del espesor de la mucosa del trígono retromolar con el objetivo de facilitar la planificación de mini implantes en la región

The retromolar triangle is a triangular area located in the mandible, posteriorly to the last molar. This region, due its thickness and bone density, is widely used for the installation of devices that provide an anchorage system for the movement of the lower molars. The aim of this research is to provide morphometric data of the mucosa thickness of the retromolar triangle. Twenty-five patients of portuguese nationality, with indication for extraction of the impacted lower third molar (right and/or left), were studied. In the region of the retromolar triangle were demarcated 3 points corresponding to the vertices of a triangle whose the base was torned for the distal face of the lower third molar and the lenght of the sides corresponded to vestibulolingual dimension of the same tooth, then was demarcated a fourth point corresponding to the geometric center of the triangle. Then, using a finger spreader with silicone stop were measured the mucosal tickness at each point. The data obtained were tabulated and analyzed. The lowest average value found was 5.5mm on the right side and the highest average value found was 7.13mm on the left side. Considering the mean values obtained at the points of the retromolar triangle mucosa measured in this study, we conclude that the retromolar triangle shows thick mucosa, so the mini-implants indicated for this region should have a long transmucosal neck.

Alveolar bone dynamics in osteoporotic rats treated with raloxifene or alendronate: confocal microscopy analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reconstruction of the Alveolar Buccal Bone Plate in Compromised Fresh Socket after Immediate Implant Placement Followed by Immediate Provisionalization

ObjectiveThe aim of this clinical report was to reestablish the buccal bone wall after immediate implant placement. The socket defect was corrected with autogenous bone, and a connective tissue graft was removed from the maxillary tuberosity to increase the thickness, height, and width of the buccal bone and gingival tissue followed by immediate provisionalization of the crown during the same operation.Clinical ConsiderationsA 66-year-old patient presented with a hopeless maxillary left central incisor with loss of the buccal bone wall. Atraumatic, flapless extraction was performed, and an immediate implant was placed in the extraction socket followed by preparation of an immediate provisional restoration. Subsequently, immediate reconstruction of the buccal bone plate was performed, using the tuberosity as the donor site, to obtain block bone and connective tissue grafts, as well as particulate bone. Finally, immediate provisionalization of the crown followed by simple sutures was performed. Cone-beam computed tomography and periapical radiographs were taken before and after surgery. After 4 months, the final prosthetic crown was made. After a 2-year follow-up, a satisfactory aesthetic result was achieved with lower treatment time and morbidity.ConclusionThis case demonstrates the effective use of immediate reconstruction of the buccal bone wall for the treatment of a hopeless tooth in the maxillary aesthetic area. This procedure efficiently promoted harmonious gingival and bone architecture, recovered lost anatomical structures with sufficient width and thickness, and maintained the stability of the alveolar bone crest in a single procedure.Clinical SignificanceIf appropriate clinical conditions exist, immediate dentoalveolar restoration may be the most conservative means of reconstructing the buccal bone wall after immediate implant placement followed by immediate provisionalization with predictable healing and lower treatment time.

Immediate loading of implants installed in a healed alveolar bony ridge or immediately after tooth extraction: an experimental study in dogs

ObjectiveTo compare the sequential healing at immediately loaded implants installed in a healed alveolar bony ridge or immediately after tooth extraction.Material and methodsIn the mandible of 12 dogs, the second premolars were extracted. After 3months, the mesial roots of the third premolars were endodontically treated and the distal roots extracted. Implants were placed immediately into the extraction sockets (test) and in the second premolar region (control). Crowns were applied at the second and third maxillary premolars, and healing abutments of appropriate length were applied at both implants placed in the mandible and adapted to allow occlusal contacts with the crowns in the maxilla. The time of surgery and time of sacrifices were planned in such a way to obtain biopsies representing the healing after 1 and 2weeks and 1 and 3months. Ground sections were prepared for histological analyses.ResultsAt the control sites, a resorption of the buccal bone of 1mm was found after 1week and remained stable thereafter. At the test sites, the resorption was 0.4mm at 1-week period and further loss was observed after 1month. The height of the peri-implant soft tissue was 3.8mm both at test and control sites. Higher values of mineralized bone-to-implant contact and bone density were seen at the controls compared with the test sites. The differences, however, were not statistically significant.ConclusionsDifferent patterns of sequential early healing were found at implants installed in healed alveolar bone or in alveolar sockets immediately after tooth extractions. However, three months after implant installation, no statistically significant differences were found for the hard- and soft-tissue dimensions.

Inicial nasal mucosa detachment using piezoelectric device in the Le Fort I osteotomy: A technical note

In maxillary Le Fort I type osteotomy the detachment of the nasal mucosa should be done carefully. Piezoelectric surgery contributed much to increase the safety of osteotomies, despite the initial advantage of minimizing the risk of injury in nervous tissue, mainly in bilateral sagittal split osteotomy; we use the piezoelectric device for the initial detachment of the nasal mucosa in the maxillary osteotomy.

Is bone transplantation the gold standard for repair of alveolar bone defects?

New strategies to fulfill craniofacial bone defects have gained attention in recent years due to the morbidity of autologous bone graft harvesting. We aimed to evaluate the in vivo efficacy of bone tissue engineering strategy using mesenchymal stem cells associated with two matrices (bovine bone mineral and α-tricalcium phosphate), compared to an autologous bone transfer. A total of 28 adult, male, non-immunosuppressed Wistar rats underwent a critical-sized osseous defect of 5 mm diameter in the alveolar region. Animals were divided into five groups. Group 1 (n = 7) defects were repaired with autogenous bone grafts; Group 2 (n = 5) defects were repaired with bovine bone mineral free of cells; Group 3 (n = 5) defects were repaired with bovine bone mineral loaded with mesenchymal stem cells; Group 4 (n = 5) defects were repaired with α-tricalcium phosphate free of cells; and Group 5 (n = 6) defects were repaired with α-tricalcium phosphate loaded with mesenchymal stem cells. Groups 2-5 were compared to Group 1, the reference group. Healing response was evaluated by histomorphometry and computerized tomography. Histomorphometrically, Group 1 showed 60.27% ± 16.13% of bone in the defect. Groups 2 and 3 showed 23.02% ± 8.6% (p = 0.01) and 38.35% ± 19.59% (p = 0.06) of bone in the defect, respectively. Groups 4 and 5 showed 51.48% ± 11.7% (p = 0.30) and 61.80% ± 2.14% (p = 0.88) of bone in the defect, respectively. Animals whose bone defects were repaired with α-tricalcium phosphate and mesenchymal stem cells presented the highest bone volume filling the defects; both were not statistically different from autogenous bone.

Reconstruction of alveolar bone defect with autogenous bone particles and osseointegrated implants: histologic analysis and 10 years monitoring

Maintaining the volume of the alveolar process after extraction can be achieved by immediate implant placement and guided bone regeneration, with or without the use of biomaterials. The authors present a case report with a 10 years follow-up, rehabilitation using osseointegrated implants in the extraction area and maintenance of the volume of the alveolar process with autogenous cortical bone shavings.