ABSTRACT
OBJECTIVES: This study aimed to evaluate the repair of critical-sized bone defects grafted with autogenous bone and mercerized bacterial cellulose membranes (BCm) salified with alendronate (ALN). METHODS: Forty-eight male Wistar rats underwent surgery to create a 5 mm-diameter bone defect in the calvarium. The removed bone was particularized, regrafted into the defect, and covered by a BCm according to the group: control group (CG), simply mercerized BCm; group 1 (G1), negatively charged BCm (BCm-CM-) salified with ALN; and group 2 (G2), positively charged BCm (BCm-DEAE+) salified with ALN. Serum samples were collected preoperatively and before euthanasia to analyze osteoprotegerin (OPG), parathyroid hormone (PTH), sclerostin (SOST), and fibroblast growth factor 23 (FGF23) levels. The animals were euthanized after 15 or 60 d. Calvaria were analyzed using quantitative microtomography (µCT). RESULTS: There was an increased level of PTH in the CG compared to the G2 group, at day 60 (p = 0.019). When analyzing the same group over time, G1 presented an increased FGF23 level on days 15 and 60 (p < 0.05). CG presented an increase in PTH (p = 0.037) at day 60. The µCT analysis detected increased trabecular separation on day 15 in G2 compared to G1 (p = 0.040). CONCLUSIONS: Salification of ionized BCm with ALN had no direct effect on bone repair; however, BCm-CM- increased the levels of FGF23 over time. BCm-DEAE+ decreased PTH levels compared to mercerized BCm. BCm-CM-salified with ALN-induced superior bone quality, with respect to trabecular separation, compared to BCm-DEAE+.
Subject(s)
Alendronate , Cellulose , Alendronate/pharmacology , Animals , Male , Rats , Rats, Wistar , Skull/diagnostic imaging , X-RaysABSTRACT
In recent years, there have been a growing number of procedures involving dental implants. Most cases, though, are characterized by bone atrophy, especially horizontal atrophy. This clinical case aims to report a technique for the expansion of the horizontal alveolar ridge. A longitudinal fracture was created in the alveolar ridge to expand the bone, followed by immediate insertion of dental implants along with a particulate allogeneic bone graft. Eight implants were placed in the maxilla, and after 12 months, a surgical reopening was performed, along with rehabilitation with a protocol-type prosthesis, for which a zirconia infrastructure was made. The patient was observed during a 10-month follow-up period in which an effective osseointegration of all implants was achieved as a result of such a technique. The split-crest technique followed by the immediate placement of implants and a particulate allogeneic bone graft proved to be effective, with a predictable osseointegration.
ABSTRACT
Introdução: a recessão gengival é definida como a mi-gração apical da margem da gengiva tendo como conse-quências a exposição radicular e a redução da faixa de gengiva inserida. O enxerto gengival livre (EGL) é uma opção de tratamento para esses casos. A estabilização do enxerto na área receptora pode influenciar o resul-tado final do procedimento. Objetivo: o presente relato de caso tem como objetivo demonstrar que o EGL pode ser fixado na região cirúrgica com o uso da cola cirúr-gica N-butyl 2-cyanoacrylate (Glubran-2), substituindo as suturas convencionais, no tratamento de regiões des-providas de gengiva inserida. Relato de caso: a investi-gação, neste estudo, se deu em uma paciente do sexo feminino de 22 anos com recessão gengival classe I de Miller no dente 41 com um defeito de 5 mm na vestibu-lar, bem como ausência de gengiva inserida. O EGL foi posicionado sobre a linha mucogengival formando um leito receptor e uma gota da cola Glubran-2 foi coloca-da em cada extremidade do enxerto para estabilização. Considerações finais: com base nos dados observados, conclui-se que a cola cirúrgica N-butyl 2-cyanoacrylate (Glubran-2) pode ser considerada como substituta ao uso de suturas convencionais.
ABSTRACT
Autologous bone is reported by scientific literature as the gold standard for the replacement of the bone loss in maxillary atrophic area. Notwithstanding, this grafting type shows several disadvantages as: The procedure morbidity, limited size of the graft and longer recovering time. Recombinant human bone morphogenetic protein type 2 (rhBMP-2) has been used as bone substitute for the reconstruction of large bone defects. The aim of this case was to report a clinical case exhibiting the reconstruction of the atrophic maxilla through using rhBMP-2 as grafting material associated with absorbable collagen sponge (ACS). At 8 months of following-up, osseointegrated implants were placed. After 2 years and 5 months of following-up, it could be observed an appropriate aesthetical and functional rehabilitation.
ABSTRACT
Objective: To demonstrate a colorimetric photoelastic analysis of tension distribution around dental implants under axial loads. Material and methods: Eight different designs of implant from two manufacturers were connected to their abutments, placed into epoxy resin blocks and observed under a polariscope coupled to a universal testing machine while subjected to axial loads of 5 N. The obtained images were quantitatively analyzed by image analysis software. Results: A strong correlation was found between the surface area and the implant fringe transition area (magenta color) of most samples (r = 0.908), and a moderate correlation was found between the fringe transition area and the mean thread height of the implants (r = 0.706, or r = 0.768 using a quadratic function). Conclusion: By this biomechanical study, it was possible to demonstrate a correlation of some implant characteristics to the colored fringe areas of tension distribution, a colorimetric method that can be used in comparative studies of photoelastic analysis. Clinical significance: An accurate planning and knowledge of oral implant biomechanics is important so that a safe and long-lasting treatment can be achieved. This biomechanical study presented some correlations of the implant features and its photoelastic behavior, information that could be used by the practitioner while choosing the implant design for each clinical situation.
ABSTRACT
The aim of this study was to evaluate the osteocalcin immunoexpression during the bone repair treated with subcutaneous adipose tissue in rats and rabbits. Fourteen rats and 14 rabbits were used in the study. A critical-sized calvarial defect was created in each animal. The animals were divided into 4 experimental groups: RC (rat control), RbC (rabbit control), RAT (rat adipose tissue), RbAT (rabbit adipose tissue). In the groups RC and RbC the defect was filled with a blood clot. In groups RAT and RbAT, the defect was filled with macerated subcutaneous adipose tissue. The euthanasia was performed at 30 days (RC and RAT) and 40 days (RbC and RbAT). Histological analysis and immunohistochemical analysis of osteocalcin protein expression were performed. Data were submitted to descriptive statistical analysis (mode). Osteocalcin immunoexpression was detected in the experimental models. Notwithstanding, RbAT showed higher positivity, especially in the adipocytes, than the group RAT group. In groups RC and RbC, the surgical wound was filled by collagen fibers. In Group RAT, the defect was composed by collagen fibers and adipocytes in the reparative sites. Similarly, in RbAT, the defect also was partially filled by collagen fibers and presence of adipocytes dispersed among the fibers. Additionally, chronic inflammatory process and areas of bone matrix deposition were observed. It may be concluded that in both animal models the adipose tissue demonstrated low osteogenic capacity. However, the rabbit animal model exhibited a more evident osteocalcin immunoexpression and a greater amount of newly formed bone matrix.
Este estudo avaliou a imunoexpressão da osteocalcina no reparo ósseo de defeitos críticos tratados com tecido adiposo subcutâneo em rato e coelho. Foram utilizados 14 ratos e 14 coelhos. Um defeito crítico foi realizado na calvária de cada animal. Os animais foram divididos em 4 grupos experimentais: CR (controle rato), CC (controle coelho), TAR (tecido adiposo do rato), TAC (tecido adiposo do coelho). Nos grupos CR e CC, o defeito foi preenchido com coágulo. Nos grupos TAR e TAC, o defeito foi preenchido com tecido adiposo subcutâneo macerado. A eutanásia dos grupos CR e TAR ocorreu com 30 dias e dos grupos CC e TAC com 40 dias. Foram realizadas análise histológica e imunoistoquímica com a proteína osteocalcina. Os dados foram submetidos à análise estatística descritiva (moda). Nos modelos experimentais foi observada a imunoexpressão de osteocalcina. Contudo, o TAC apresentou maior imunoexpressão entre os adipócitos quando comparado ao TAR. Nos grupos CR e CC a ferida cirúrgica foi preenchida por fibras colágenas. No grupo TAR foi observado o preenchimento por fibras colágenas e presença de adipócitos no interior deste tecido. No grupo TAC o defeito foi preenchido parcialmente por fibras colágenas, com presença de adipócitos dispersos entre as fibras. Além disso, foi observado processo inflamatório crônico e sinais de neoformação óssea. Conclui-se que em ambos os modelos animais o enxerto de tecido adiposo apresentou baixa capacidade osteogênica. Contudo, o modelo animal coelho apresentou uma imunoexpressão da osteocalcina mais evidente e maior quantidade de matriz óssea neoformada.
Subject(s)
Animals , Rabbits , Rats , Osteocalcin/metabolism , Skull/injuries , Skull/metabolism , Subcutaneous Fat/transplantation , Wound Healing/physiology , Disease Models, Animal , Immunoenzyme Techniques , Rats, WistarABSTRACT
Introduction: The insufficient amount of attached gingiva and the abnormal insertion of the labial frenulum may be related. When this occurs, it is common to associate frenectomy techniques with free gingival graft (FGG). Objective: To evaluate the clinical and histological staining difference and blood flow when the FGG is or is not associated with frenectomy. Material and methods: Ten patients were selected in the Dentistry Clinics of the Positivo University and divided into two groups (n = 5): group GF (graft/frenectomy), with association of FGG and frenectomy in the V sextant, and group G (graft), in which only the FGG was performed in the V sextant. Clinical examination, initial standardized photographs and post-surgery following-up for seven, 14 and 21 days were executed. For histological analysis the excesses of the graft tissues of a patient from each group were removed. Results: Clinically, it was observed in both groups after seven and 14 post-operative days, superficial necrosis of the tissue and color similar to the surrounding soft tissue. At 21 days, there is the total reduction of the necrosed tissue, and it was not seen the color difference between groups. Histologically, the difference between groups is related to the epithelial tissue, which was thicker in group G. Conclusion: Clinical (color) and histological (vascularization) significant differences were not observed between groups GF and G.
ABSTRACT
The aim of this study was to evaluate the osteocalcin immunoexpression during the bone repair treated with subcutaneous adipose tissue in rats and rabbits. Fourteen rats and 14 rabbits were used in the study. A critical-sized calvarial defect was created in each animal. The animals were divided into 4 experimental groups: RC (rat control), RbC (rabbit control), RAT (rat adipose tissue), RbAT (rabbit adipose tissue). In the groups RC and RbC the defect was filled with a blood clot. In groups RAT and RbAT, the defect was filled with macerated subcutaneous adipose tissue. The euthanasia was performed at 30 days (RC and RAT) and 40 days (RbC and RbAT). Histological analysis and immunohistochemical analysis of osteocalcin protein expression were performed. Data were submitted to descriptive statistical analysis (mode). Osteocalcin immunoexpression was detected in the experimental models. Notwithstanding, RbAT showed higher positivity, especially in the adipocytes, than the group RAT group. In groups RC and RbC, the surgical wound was filled by collagen fibers. In Group RAT, the defect was composed by collagen fibers and adipocytes in the reparative sites. Similarly, in RbAT, the defect also was partially filled by collagen fibers and presence of adipocytes dispersed among the fibers. Additionally, chronic inflammatory process and areas of bone matrix deposition were observed. It may be concluded that in both animal models the adipose tissue demonstrated low osteogenic capacity. However, the rabbit animal model exhibited a more evident osteocalcin immunoexpression and a greater amount of newly formed bone matrix.
