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Background and objectives: Calcium phosphates have been widely used as bone substitutes, but their properties are limited to osteoconduction. The association of calcium phosphates with osteoinductive bioactive molecules has been used as a strategy in regenerative medicine. Melatonin has been studied due to its cell protection and antioxidant functions, reducing osteoclastic activity and stimulating newly formed bone. This study aimed to evaluate the effect of topical application of melatonin associated with nanostructured carbonated hydroxyapatite microspheres in the alveolar bone repair of Wistar rats through histological and histomorphometric analysis. Materials and Methods: Thirty female Wistar rats (300 g) were used, divided randomly into three experimental groups (n = 10), G1: nanostructured carbonated hydroxyapatite microspheres associated with melatonin gel (CHA-M); G2: nanostructured carbonated hydroxyapatite (CHA); G3: blood clot (without alveolar filling). The animals were euthanized after 7 and 42 days of the postoperative period and processed for histological and histomorphometric evaluation. Kruskal-Wallis and Dunn's post-test were applied to investigate statistical differences between the groups at the same time point for new bone and connective tissue variables. Mann-Whitney was used to assess statistical differences between different time points and in the biomaterial variable. Results: Results showed a greater volume of residual biomaterial in the CHA-M than the CHA group (p = 0.007), and there were no significant differences in terms of newly formed bone and connective tissue between CHA and CHA-M after 42 days. Conclusions: This study concluded that both biomaterials improved alveolar bone repair from 7 to 42 days after surgery, and the association of CHA with melatonin gel reduced the biomaterial's biodegradation at the implanted site but did not improve the alveolar bone repair.
Assuntos
Melatonina , Ratos , Animais , Feminino , Melatonina/farmacologia , Melatonina/uso terapêutico , Ratos Wistar , Materiais Biocompatíveis/uso terapêutico , Durapatita , Fosfatos de Cálcio/farmacologia , Fosfatos de Cálcio/uso terapêutico , CarbonatosRESUMO
BACKGROUND: The degree of biodegradation and the inflammatory response of membranes employed for guided bone regeneration directly impact the outcome of this technique. This study aimed to evaluate four different experimental versions of Poly (L-lactate-co-Trimethylene Carbonate) (PTMC) + Poly (L-lactate-co-glycolate) (PLGA) membranes, implanted in mouse subcutaneous tissue, compared to a commercially available membrane and a Sham group. METHODS: Sixty Balb-C mice were randomly divided into six experimental groups and subdivided into 1, 3, 6 and 12 weeks (n = 5 groups/period). The membranes (1 cm2) were implanted in the subcutaneous back tissue of the animals. The samples were obtained for descriptive and semiquantitative histological evaluation (ISO 10993-6). RESULTS: G1 and G4 allowed tissue adhesion and the permeation of inflammatory cells over time and showed greater phagocytic activity and permeability. G2 and G3 detached from the tissue in one and three weeks; however, in the more extended periods, they presented a rectilinear and homogeneous aspect and were not absorbed. G2 had a major inflammatory reaction. G5 was almost completely absorbed after 12 weeks. CONCLUSIONS: The membranes are considered biocompatible. G5 showed a higher degree of biosorption, followed by G1 and G4. G2 and G3 are considered non-absorbable in the studied periods.
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The control of postoperative bleeding represents one of the main intercurrent events associated with soft tissue surgical procedures in the oral cavity. In this context, platelet-rich fibrin (PRF) membranes are materials with great potential for optimizing soft tissue healing and induction of hemostasis. This interventional case series describes the treatment of 10 patients with excisional biopsy of benign oral cavity lesions, following a screening sequence at the surgery clinic of a Brazilian dental school between the years of 2015 and 2017. After treatment with PRF, patients presented mean time for postoperative hemostasis of 10.3 ± 2.5 s, requiring the average use of three membranes to cover the surgical area. The results suggest that the use of platelet-rich fibrin membranes may represent a feasible alternative hemostatic material for the treatment of oral lesions.
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Hemostáticos/farmacologia , Doenças Mandibulares/patologia , Doenças Mandibulares/cirurgia , Doenças Maxilares/patologia , Doenças Maxilares/cirurgia , Hemorragia Bucal/prevenção & controle , Fibrina Rica em Plaquetas , Hemorragia Pós-Operatória/prevenção & controle , Cirurgia Bucal/métodos , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cicatrização/efeitos dos fármacosRESUMO
BACKGROUND: The presence of nonresorbable residual granules of hydroxyapatite (HA) may decrease the bone/implant interface. To balance resorption and bone formation biphasic calcium phosphate ceramics compounds applied at different rates have been studied. PURPOSE: The aim of this trial was to compare the clinical, histological, and histomorphometric responses of two new biphasic calcium phosphate biomaterials in fresh dental sockets after 3 and 6 months. MATERIALS AND METHODS: Forty-eight volunteers were divided randomly and double-blindly into 4 groups of 12 individuals: Clot (C), BoneCeramic (BC), Biomaterial 1 (B1), and Biomaterial 2 (B2) groups. Three and six months later, samples were obtained, and histological and histomorphometric sections were evaluated, focusing on the presence of fibrous connective tissue (CT) and newly formed bone. Statistical analysis was performed (P < .05%). RESULTS: The quantification of crystalline phases showed B1 composed of HA (60.28%) and ß-TCP (39.72%); B2 composed of HA (78.21%) and ß-TCP (21.79%); and BC composed of HA (61%) and ß-TCP (39%). The B1 group showed the most newly formed bone (69.3% ± 6.03%), followed by the BC (51.6 ± 12.34%), B2 (46.6 ± 7.66%), and C groups (45.4 ± 7.98%), and less connective tissue and biomaterial remained in the B1 group after 6 months. CONCLUSION: B1 group showed the greatest amount of newly formed bone after 6 months.
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Materiais Biocompatíveis , Substitutos Ósseos , Implantes Dentários , Hidroxiapatitas , Nanoestruturas , Adolescente , Adulto , Idoso , Planejamento de Prótese Dentária , Feminino , Humanos , Masculino , Teste de Materiais , Pessoa de Meia-Idade , Adulto JovemRESUMO
INTRODUCTION: The purpose of this study was to evaluate the biocompatibility of a self-adhesive gutta-percha material and compare it with that of conventional gutta-percha. METHODS: Standard quantities of bioactive gutta-percha and conventional gutta-percha were directly inserted subcutaneously into the dorsal connective tissue of 30 BALB/c mice according to ISO 10993-6. After 7, 21, and 63 days each, 10 animals were euthanized, and the materials and surrounding tissue were removed. Tissue samples were subjected to histological processing resulting in 5-µm-thick slices stained with hematoxylin-eosin and Gomori trichrome stain. A grade ranging from I-IV was used to classify the inflammatory reaction. The Mann-Whitney U test with Bonferroni correction was used to compare the grade of inflammation induced by the materials at each time point. Qualitative evaluation of biocompatibility over time was also performed. RESULTS: Bioactive gutta-percha was more biocompatible than conventional gutta-percha at each time interval (P < .05). Tissue exposed to bioactive gutta-percha reached "no inflammation" (grade I) at the 21-day interval, whereas it took 63 days for the conventional gutta-percha to reach the "slight inflammation" level (grade II). CONCLUSIONS: Bioactive gutta-percha presented good tissue reaction at all time points. It may serve as an alternative to gutta-percha in terms of biocompatibility.