ABSTRACT
The aim of this study was to evaluate the osseointegration of implants placed in rat tibia sites grafted with Deproteinized Bovine Bone (DBB) and Native Bone (NB). Twenty-eight rats were divided into two groups according to the type of substrate in which the implants were to be placed: NB - implants placed in native bone; DBB - implants placed in areas grafted with DBB. In the DBB group, the bone defect was made and filled with the bone substitute 60 days before placing the implant. The animals were euthanized 15 or 45 days after implant placement. Osseointegration was assessed by the removal torque, volume of mineralized tissues around the implants (BV/TV), bone-implant contact (%BIC), and bone between threads (%BBT). The implants placed in NB presented higher removal torque (8.00 ± 1.26 Ncm vs. 2.33 ± 0.41 Ncm at 15 days and 22.00 ± 2.44 Ncm vs. 4.00 ± 1.41 Ncm at 45 days), higher %BV/TV (47.92 ± 1.54% vs. 33.33 ± 4.77% at 15 days and 70.06 ± 0.91% vs. 39.89±5.90%at 45 days), higher %BIC (39.68 ± 5.02% vs. 9.12 ± 5.56% at 15 days and 83.23 ± 4.42% vs. 18.81 ± 7.21% at 45 days), and higher %BBT (34.33 ± 5.42% vs. 13.24 ± 8.72% at 15 days and 82.33 ± 3.13% vs. 22.26 ± 8.27% at 45 days) than the implants placed in DBB grafted areas. The degree of osseointegration was lower in implants placed in the area grafted with DBB than in NB in rat tibias.
O objetivo deste estudo foi avaliar a osseointegração de implantes instalados em sítios enxertados com Osso Bovino Desproteinizado (DBB) e Osso Nativo (NB). Vinte e oito ratos foram alocados em dois grupos de acordo com o tipo de substrato onde os implantes foram colocados: NB - Implantes colocados em osso nativo; DBB - Implantes instalados em áreas enxertadas com DBB. No grupo DBB, o defeito ósseo foi confeccionado e preenchido com o substituto ósseo 60 dias antes da instalação do implante. Os animais foram sacrificados após 15 e 45 dias da colocação do implante. A osseointegração foi avaliada pelo torque de remoção, volume de tecidos mineralizados ao redor dos implantes (%BV/TV), contato direto do osso com o implante (%BIC), e área de osso entre roscas dos implantes (%BBT). Os implantes instalados em NB tiveram um maior torque de remoção (8.00 ± 1.26 Ncm vs. 2.33 ± 0.41 Ncm aos 15 dias e 22.00 ± 2.44 Ncm vs. 4.00 ± 1.41 Ncm aos 45 dias), ummaior%BV/TV (47.92 ±1.54% vs. 33.33 ± 4.77% aos 15 dias e 70.06 ± 0.91% vs. 39.89 ± 5.90% aos 45 dias), um maior %BIC (39.68 ± 5.02% vs. 9.12 ± 5.56% aos 15 dias e 83.23 ± 4.42% vs. 18.81 ± 7.21% aos 45 dias), e um maior %BBT (34.33 ± 5.42% vs. 13.24 ± 8.72% aos 15 dias e 82.33 ± 3.13% vs. 22.26 ± 8.27% aos 45 dias) que os implantes colocados nas áreas enxertadas com DBB. Implantes instalados em áreas enxertadas com DBB apresentaram menor osseointegração que os implantes instalados no osso nativo em tíbias de ratos.
Subject(s)
Bone Substitutes , Dental Implants , Animals , Cattle , Osseointegration , Rats , TorqueABSTRACT
ABSTRACT The aim of this study was to evaluate the osseointegration of implants placed in rat tibia sites grafted with Deproteinized Bovine Bone (DBB) and Native Bone (NB). Twenty-eight rats were divided into two groups according to the type of substrate in which the implants were to be placed: NB - implants placed in native bone; DBB - implants placed in areas grafted with DBB. In the DBB group, the bone defect was made and filled with the bone substitute 60 days before placing the implant. The animals were euthanized 15 or 45 days after implant placement. Osseointegration was assessed by the removal torque, volume of mineralized tissues around the implants (BV/TV), bone-implant contact (%BIC), and bone between threads (%BBT). The implants placed in NB presented higher removal torque (8.00 ± 1.26 Ncm vs. 2.33 ± 0.41 Ncm at 15 days and 22.00 ± 2.44 Ncm vs. 4.00 ± 1.41 Ncm at 45 days), higher %BV/TV (47.92 ± 1.54% vs. 33.33 ± 4.77% at 15 days and 70.06 ± 0.91% vs. 39.89 ± 5.90% at 45 days), higher %BIC (39.68 ± 5.02% vs. 9.12 ± 5.56% at 15 days and 83.23 ± 4.42% vs. 18.81 ± 7.21% at 45 days), and higher %BBT (34.33 ± 5.42% vs. 13.24 ± 8.72% at 15 days and 82.33 ± 3.13% vs. 22.26 ± 8.27% at 45 days) than the implants placed in DBB grafted areas. The degree of osseointegration was lower in implants placed in the area grafted with DBB than in NB in rat tibias.
RESUMO O objetivo deste estudo foi avaliar a osseointegração de implantes instalados em sítios enxertados com Osso Bovino Desproteinizado (DBB) e Osso Nativo (NB). Vinte e oito ratos foram alocados em dois grupos de acordo com o tipo de substrato onde os implantes foram colocados: NB - Implantes colocados em osso nativo; DBB - Implantes instalados em áreas enxertadas com DBB. No grupo DBB, o defeito ósseo foi confeccionado e preenchido com o substituto ósseo 60 dias antes da instalação do implante. Os animais foram sacrificados após 15 e 45 dias da colocação do implante. A osseointegração foi avaliada pelo torque de remoção, volume de tecidos mineralizados ao redor dos implantes (%BV/TV), contato direto do osso com o implante (%BIC), e área de osso entre roscas dos implantes (%BBT). Os implantes instalados em NB tiveram um maior torque de remoção (8.00 ± 1.26 Ncm vs. 2.33 ± 0.41 Ncm aos 15 dias e 22.00 ± 2.44 Ncm vs. 4.00 ± 1.41 Ncm aos 45 dias), um maior %BV/TV (47.92 ± 1.54% vs. 33.33 ± 4.77% aos 15 dias e 70.06 ± 0.91% vs. 39.89 ± 5.90% aos 45 dias), um maior %BIC (39.68 ± 5.02% vs. 9.12 ± 5.56% aos 15 dias e 83.23 ± 4.42% vs. 18.81 ± 7.21% aos 45 dias), e um maior %BBT (34.33 ± 5.42% vs. 13.24 ± 8.72% aos 15 dias e 82.33 ± 3.13% vs. 22.26 ± 8.27% aos 45 dias) que os implantes colocados nas áreas enxertadas com DBB. Implantes instalados em áreas enxertadas com DBB apresentaram menor osseointegração que os implantes instalados no osso nativo em tíbias de ratos.
ABSTRACT
OBJECTIVES: The aim of this study was to evaluate the effect of a hydrophilic surface on the osseointegration in grafted areas with deproteinized bovine bone (DBB) and with biphasic ceramics of hydroxyapatite/ß-tricalcium phosphate (HA/TCP). MATERIAL AND METHODS: Fifty-six rats were randomly allocated to four groups with 14 animals each: DBB: DBB+Machined surface; HA/TCP: HA/TCP+Machined surface; DBB-H: DBB+Hydrophilic surface; HA/TCP-H: HA/TCP+Hydrophilic surface. The bone defects were performed at the proximal epiphysis of the tibia. Then, the defects were filled with the biomaterials. After 60 days, the implants were placed in the grafted areas. The animals were submitted to euthanasia at periods of 15 and 45 days after the implants' placement. The osseointegration was assessed by biomechanical, microtomographic, and histometric analyses. In addition, the expression of bone morphogenetic protein-2 (BMP-2), alkaline phosphatase (ALP), and osteocalcin (OCN) was evaluated by immunohistochemistry. RESULTS: The HA/TCP-H group presented higher removal torque values and more mineralized tissue in the vicinity of the implants compared with the HA/TCP group. The DBB-H and HA/TCP-H groups presented higher values of bone-implant contact (at 15 and 45 days), of bone between the threads (45 days), and expression of BMP-2 (45 days) than the DBB and HA/TCP groups. Furthermore, the DBB-H group presented a higher expression of ALP than the DBB group (15 days). CONCLUSION: In conclusion, implants with a hydrophilic surface improve osseointegration in grafted areas compared to implants with machined surfaces in a rat tibia model.
