RESUMO
Hydroxyapatite (HA) is a hard mineral component of mineralized tissues, mainly composed of calcium and phosphate. Due to its bioavailability, HA is potentially used for the repair and regeneration of mineralized tissues. For this purpose, the properties of HA are significantly improved by adding natural and synthetic materials. In this sense, the germanium (Ge) mineral was loaded in HA biomaterial by cold isostatic pressure for the first time and characterization and biocompatibility using bone marrow mesenchymal stem cells (BM-MSCs) were investigated. The addition of Ge at 5% improved the solubility (3.32%), stiffness (18.34 MPa), water holding (31.27%) and biodegradation (21.87%) properties of HA, compared to control. Compared to all composite biomaterials, the drug-releasing behavior of HA-3% Ge was higher at pH 1 and 3 and the maximum drug release was obtained at pH 7 and 9 with HA-5% Ge biomaterials. Among the different mediums tested, the DMEM-medium showed a higher drug release rate, especially at 60 min. HA-Ge biomaterials showed better protein adhesion and apatite layer formation, which ultimately proves the compatibility in BM-MSCs culture. Except for higher concentrations of HA (5 and 10 mg/mL), the different concentrations of Ge and HA and wells coated with 1% of HA-1% Ge had higher BM-MSCs growth than control. All these findings concluded that the fabricated HA biomaterials loaded with Ge could be the potential biomaterial for culturing mammalian cells towards mineralized tissue repair and regeneration.
Assuntos
Germânio , Células-Tronco Mesenquimais , Animais , Materiais Biocompatíveis/química , Regeneração Óssea , Cálcio/metabolismo , Durapatita/farmacologia , Germânio/metabolismo , Germânio/farmacologia , Mamíferos , Células-Tronco Mesenquimais/metabolismo , Osteogênese , Alicerces Teciduais/química , Água/metabolismoRESUMO
OBJECTIVES: The aim of this study is to evaluate the effect of the surface modification and cervical implant design on the bone remodeling in implants installed at the crestal and subcrestal bone level. METHODS: Ten American Fox Hound of approximately 1 year of age, each weighing approximately 14 to 15âkg, were used for this study. Two different dental implant macrodesign were used: cylindric-conical with 3.5âmm of diameter and 9 in length (implant A) and conical with 2.9âmm of diameter and 9âmm in length (implant B). Two surfaces were used: sandblasting and acid etching (surface 1) and sandblasting and acid etching, then maintained in an isotonic solution of 0.9% sodium chloride (surface 2). Four groups were performed (nâ=â20 implants): Group A1 (implant A with the surface 1), Group A2 (implant A with surface 2), Group B1 (implant B with surface 1), and Group B2 (implant B with surface 2). The mandibular premolars and molars (P1, P2, P3, M1) were removed and, after 2 months of healing, implants were inserted at the crestal and 2âmm subcrestal position related to the buccal bone level. Analysis was performed at 4 and 8 weeks. Histomorphometry with longitudinal measurements and bone implant contact, bone remodeling and implant stability quotient analysis were realized. RESULTS: The surface 2 showed to get more close contact between implant and new bone formed after implant placement and more stability surrounding platform both at 4 and 8 weeks. Surface 2 groups and subrestally placed showed to have better results in terms of linear measurements, with less bone loss and soft tissue distance to the IS. The data showed significant differences among the groups (Pâ<â0.001). CONCLUSIONS: Surface modification (surface 2) has shown to be an effective alternative to conventional surface with better results in situations placed subcrestally and combined with implant design.