RESUMEN
OBJECTIVES: The aim of this study was to evaluate the bone tissue response to fiber-reinforced composite (FRC) in comparison with titanium (Ti) implants after 12 weeks of implantation in cancellous bone using histomorphometric and ultrastructural analysis. MATERIALS AND METHODS: Thirty grit-blasted cylindrical FRC implants with BisGMA-TEGDMA polymer matrix were fabricated and divided into three groups: (1) 60s light-cured FRC (FRC-L group), (2) 24h polymerized FRC (FRC group), and (3) bioactive glass FRC (FRC-BAG group). Titanium implants were used as a control group. The surface analyses were performed with scanning electron microscopy and 3D SEM. The bone-implant contact (BIC) and bone area (BA) were determined using histomorphometry and SEM. Transmission electron microscopy (TEM) was performed on Focused Ion Beam prepared samples of the intact bone-implant interface. RESULTS: The FRC, FRC-BAG and Ti implants were integrated into host bone. In contrast, FRC-L implants had a consistent fibrous capsule around the circumference of the entire implant separating the implant from direct bone contact. The highest values of BIC were obtained with FRC-BAG (58±11%) and Ti implants (54±13%), followed by FRC implants (48±10%), but no significant differences in BIC or BA were observed (p=0.07, p=0.06, respectively). TEM images showed a direct contact between nanocrystalline hydroxyapatite of bone and both FRC and FRC-BAG surfaces. CONCLUSION: Fiber-reinforced composite implants are capable of establishing a close bone contact comparable with the osseointegration of titanium implants having similar surface roughness.
Asunto(s)
Resinas Compuestas/química , Implantes Dentales , Materiales Dentales/química , Diseño de Prótesis Dental , Cabeza Femoral/ultraestructura , Vidrio/química , Oseointegración/fisiología , Animales , Bisfenol A Glicidil Metacrilato/química , Interfase Hueso-Implante/anatomía & histología , Durapatita/química , Femenino , Imagenología Tridimensional/métodos , Curación por Luz de Adhesivos Dentales/métodos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Nanopartículas/química , Polietilenglicoles/química , Polimerizacion , Ácidos Polimetacrílicos/química , Conejos , Espectrometría por Rayos X , Propiedades de Superficie , Factores de Tiempo , Titanio/químicaRESUMEN
The aim of this study was to investigate bone response to bioactive fiber-reinforced composite (FRC) implants under two polymerization conditions. Glass-fiber-dimethacrylate composite was tested as prepolymerized cylinder-shaped FRC implants and as cylindrical FRC implants polymerized in situ with blue light transmitted and scattered by the glass fibers. Ten FRC implants (6 prepolymerized and 4 in situ-polymerized implants) were placed in the right tibias of 3 pigs by means of a press-fit technique. After 12 weeks, light microscopy revealed only mild foreign-body reaction, with no accumulation of inflammatory cells on both the prepolymerized and the in situ-polymerized implants. The prepolymerized implants appeared to be fully integrated, whereas the in situ-polymerized implants were almost completely surrounded by a fibrous capsule. The present study suggests that in situ polymerization of FRC implants results in fibrous capsule formation and prevents integration with bone.
Asunto(s)
Resinas Compuestas/química , Implantes Dentales , Curación por Luz de Adhesivos Dentales/efectos adversos , Oseointegración/efectos de la radiación , Animales , Resinas Compuestas/efectos de la radiación , Femenino , Reacción a Cuerpo Extraño/etiología , Vidrio , Implantes Experimentales , Curación por Luz de Adhesivos Dentales/métodos , Ensayo de Materiales , Proyectos Piloto , Distribución Aleatoria , Porcinos , Tibia/cirugíaRESUMEN
OBJECTIVES: The aims of this study were to evaluate bone-to-implant contact (BIC) and the osteoconductive capacity of bioactive fiber-reinforced composite implant (FRC) in vivo. MATERIAL AND METHODS: Threaded sand-blasted FRC implants and threaded FRC implants with bioactive glass (BAG) were fabricated for the study. Titanium implants were used as a reference. Eighteen implants (diameter 4.1 mm, length 10 mm) were implanted in the tibia of six pigs using the press-fit technique. The animals were sacrificed after 4 and 12 weeks. Histomorphometric and scanning electron microscopic (SEM) analyses were performed to characterize BIC. RESULTS: In general, the highest values of BIC were measured in FRC-BAG implants, followed by FRC and Ti implants. At 4 weeks, the BIC was 33% for threaded FRC-BAG, 27% for FRC and 19% for Ti. At 12 weeks, BIC was 47% for threaded FRC-BAG, 40% for FRC and 42% for Ti. Four weeks after implantation, all the implants appeared biologically fixed by a newly formed woven bone arranged in the thin bone trabeculae filling the gap between the implant and the bone of the recipient site. Twelve weeks after implantation, the thickness of the woven bone trabeculae had increased, especially around the FRC-BAG implants. CONCLUSION: Our results suggest that the FRC implant is biocompatible in bone. The biological behavior of FRC was comparable to that of Ti after 4 and 12 weeks of implantation. Furthermore, the addition of BAG to the FRC implant increased peri-implant osteogenesis and bone maturation.
