Orthodontic force increases interleukin-1β and tumor necrosis factor-α expression and alveolar bone loss in periodontitis

Background: The present study aims to evaluate the effects of orthodontic movement (OM) on the periodontal tissues of rats with ligature-induced periodontal disease. Methods: Eighty-eight rats were divided into four groups: 1) negative control (sham operated); 2) periodontal disease; 3) OM; and 4) periodontal disease followed by OM (OMP). Rats were sacrificed 3 hours or 1, 3, or 7 days after OM commencement. Bone volume fraction (BVF) and bone mineral density (BMD) were assessed in hemimaxillae by microcomputed tomography analysis. Expression of the proinflammatory cytokines interleukin (IL)-1β and tumor necrosis factor (TNF)-α were evaluated in gingival samples by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, and in the furcation region by immunohistochemistry analysis (IHC). Results: The OMP group had lower BVF and BMD levels compared to the other groups at day 7 (P <0.05). Maximum messenger ribonucleic acid expression of both cytokines was observed in the OMP group at day 1 (P <0.05). In the same period, all proteins were expressed in high levels for all test groups compared to the control group. The number of cells positive for IL-1β and TNF-α by IHC was highest in the OMP group at day 1, with progressive reduction thereafter. Conclusion: The results suggest that OM acts synergistically with periodontal disease in periodontal breakdown through upregulation of proinflammatory cytokines.

Histological analysis of the periodontal ligament and alveolar bone during dental movement in diabetic rats subjected to low-level laser therapy

Objective: The purpose of this research was to evaluate the histological changes of the periodontal ligament and alveolar bone during dental movement in diabetic rats subjected to low level laser therapy (LLLT).Methods: The movement of the upper molar was performed in 60 male Wistar rats divided into four groups (n = 15): CTR (control), DBT (diabetic), CTR/LT (irradiated control) and DBT/LT (irradiated diabetic). Diabetes was induced with alloxan (150 mg/kg, i.p.). LLLT was applied with GaAlAs laser at 780 nm (35 J/cm(2)). After 7, 13 and 19 days, the periodontal ligament and alveolar bone were histologically analyzed.Results: The mean of osteoblasts (p < 0.01) and blood vessels (p < 0.05) were significantly decreased in DBT compared with CTR at 7 days, whereas the mean of osteoclasts was lower at 7 (p < 0.001) and 13 days (p < 0.05). In DBT/LT, only the mean of osteoclasts was lower than in CTR (p < 0.05) at 7 days, but no difference was observed at 13 and 19 days (p > 0.05). The collagenization of the periodontal ligament was impaired in DBT, whereas DBT/LLT showed density/disposition of the collagen fibers similar to those observed in CTR.Conclusions: LLLT improved the periodontal ligament and alveolar bone remodeling activity in diabetic rats during dental movement. (C) 2014 Elsevier B.V. All rights reserved.

Postsurgical Alveolar Bone Graft Patients: Elaboration and Application of a Data-Gathering Instrument for Nutrition and Nursing

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Alcoholic and isocaloric diet, but not ovariectomy, influence the apoptosis of bone cells within the alveolar bone crest of rats

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

Cimetidine Reduces Alveolar Bone Loss in Induced Periodontitis in Rat Molars

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

Treatment with tacrolimus enhances alveolar bone formation and decreases osteoclast number in the maxillae: A histomorphometric and ultrastructural study in rats

Recent studies have suggested that tacrolimus monotherapy is a beneficial therapeutic alternative for the normalization of cyclosporin- induced bone loss in animal models and humans. The mechanism accounting for this action is unclear at present. In the present study, we attempted to determine the effect of tacrolimus monotherapy on alveolar bone using histological, histomorphometrical and transmission electron microscopy (TEM).Groups of rats (n= 10 each) were treated with either tacrolimus (1mg/ kg/ day, s.c.) or drug vehicle for 60 days. Fragments containing maxillary molars were processed for light microscopy to investigate the alveolar bone volume, trabecular separation, number of osteoclasts and osteoblasts, and transmission electron microscopy to investigate their ultrastructural basic phenotype.Treatment with tacrolimus monotherapy during 60 days may induce increases in alveolar bone volume (BV/ TV,%; P < 0.05) and a non- significant decrease in trabecular separation (Tb. Sp, mm; P > 0.05), represented by a decrease in osteoclast number (N. Oc/ BS; P < 0.05) and maintenance of osteoblast number (N. Ob/ BS; P > 0.05). Osteoblasts were often observed as a continuous layer of active cells on the bone surface. Osteoclasts appeared to be detached from the resorbed bone surface, which was often filled by active osteoblasts and collagen- rich matrix. Moreover, osteoclasts in the treated group were frequently observed as inactive cells (without ruffled border, clear zone and detached from the bone surface).Within the limits of the present study, we conclude that tacrolimus leads to an increase in alveolar bone formation, which probably exerts action on osteoclasts. Tacrolimus could, therefore, play a crucial role in the control of both early osteoclast differentiations from precursors, as well as in functional activation.

Data collection on bone density of mandibular alveolar bone on a Hounsfield scale of the dental apex of the cranial root of the first inferior molar in dogs using computed tomography at FMVZ-UNESP

The head is the most important and specialized region in the body because it contains a range of specialized organs and, because it has interconnections between specialized organs, there is a great overlap of images. Thus, computed tomography (CT) helps in diagnosing diseases in this region, such as oral conditions, as they provide millimetric slices or cuts and demonstrate the relationship between the various anatomical structures involved, in volume and depth. Within dentistry, CT helps in the identification of pathological processes such as infection, tumors, visualization of embedded teeth and bone bed. This study aimed to assess the density of the mandibular alveolar bone at a determined point to later predict how periodontal disease is involved in bone resorption. For this, we performed a blind retrospective study (n = 124) of the CT scan files of dog skulls at FMVZ-UNESP in order to determine the density of the jaw bone using a Hounsfield scale, in the region of the dental apex of the cranial root of the first molar tooth in dogs. The results obtained were evaluated using mean and standard deviation (27.28 +/- 9.53 HU) in order to predict the normal density of the mandibular alveolar bone in the studied region. Thus, this data analysis allows a more concise evaluation of bone resorption of mandibular alveolar bone and, therefore, provides an adequate surgical planning in cases of osteosynthesis given mainly by the presence of installed periodontal disease.

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.

The H2S-releasing naproxen derivative, ATB-346, inhibits alveolar bone loss and inflammation in rats with ligature-induced periodontitis

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

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)

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.

Exenatide and sitagliptin decrease interleukin 1β, matrix metalloproteinase 9, and nitric oxide synthase 2 gene expression but does not reduce alveolar bone loss in rats with periodontitis

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

Alveolar Bone Morphology in Patients With Bilateral Complete Cleft Lip and Palate in the Mixed Dentition: Cone Beam Computed Tomography Evaluation

Objectives: To verify the thickness and level of alveolar bone around the teeth adjacent to the cleft by means of cone beam computed tomography (CBCT) in patients with complete bilateral cleft lip and palate prior to bone graft surgery and orthodontic intervention. Method: The sample comprised 10 patients with complete bilateral cleft lip and palate (five boys and five girls) in the mixed dentition. The mean age was 9.5 years, and all subjects showed a G3 interarch relationship according to the Bauru index. The thickness of alveolar bone surrounding the maxillary incisors and the maxillary canines was measured in CBCT axial section using the software iCAT Xoran System. The distance between the alveolar bone crest and the cement-enamel junction (CEJ) was measured in cross sections. Results: The tomography images showed a thin alveolar bone plate around teeth adjacent to clefts. No bone dehiscence was observed in teeth adjacent to clefts during the mixed dentition. A slight increase in the distance between the alveolar bone crest and the CEJ was observed in the mesial and lingual aspects of canines adjacent to cleft. Conclusion: In patients with BCLP in the mixed dentition, teeth adjacent to the alveolar cleft are covered by a thin alveolar bone plate. However, the level of alveolar bone crest around these teeth seems to be normal, and no bone dehiscence was identified at this age.