Nondecalcified histologic study of bone response to titanium implants topographically modified by laser with and without hydroxyapatite coating.

The purpose of this study was nondecalcified histologic analysis of titanium implants modified by laser with and without hydroxyapatite. Implants with three modified surfaces were inserted into rabbit tibias: group 1, machined surface; group 2, irradiated (laser); and group 3, irradiated and hydroxyapatite coated (biomimetic method). The mean surface roughness (Ra) scores of groups 2 and 3 were higher than that of group 1. Boneimplant contact measurements at 30 and 60 days for groups 2 and 3 were higher than for group 1. Bone area at 30 and 60 days for group 2 was higher than for groups 1 and 3. Titanium implants modified by laser with and without hydroxyapatite exhibit increased early osseointegration.

Surface and biomechanical study of titanium implants modified by laser with and without hydroxyapatite coating, in rabbits.

Surface and biomechanical analysis of titanium implant surfaces modified by laser beam with and without hydroxyapatite. Titanium implants with 3 different surfaces were inserted into the tibias of 30 rabbits: group I (GI) machined surface (control group), group II irradiated with laser (GII), and group III irradiated with laser and hydroxyapatite coating applied-biomimetic method (GIII). Topographical analysis with scanning electron microscopy was made before surgery in the tibia. These rabbits were distributed into 2 periods of observation: 4 and 8 weeks postsurgery, after which biomechanical analysis (removal torque) was conducted. Statistical analysis used the Student-Newman-Keuls method. Surface showed roughness in GII and GIII. Biomechanical analysis demonstrated values with significant differences in GII and GIII. Titanium implants modified by laser irradiation can increase osseointegration during the initial phase.

Morphology of autogenous bone graft and castor oil polyurethane in the infraorbital rim of rabbits: a comparative study / Estudo morfológico comparativo do enxerto ósseo autógeno e polímero de mamona em rebordo infra-orbitário de coelhos

PURPOSE: Morphological study comparing castor oil polyurethane and autogenous bone graft to repair bone defect in zygomatic bone of rabbits. METHODS: Twenty-four adult, male New Zealand rabbits were randomly distributed between two groups of twelve. Bone defects of 5mm in diameter were cut through the zygomatic bone and filled with polyurethane discs in the experimental group or autogenous bone harvested from the tibia in the control group. Animals were sacrificed after 30, 60 or 90 days, and the zygomatic bones were macro- and microscopically analyzed. Student's, Fisher's, chi-squared and McNemar's tests were used for statistical analysis. RESULTS: Both the castor oil polyurethane and the autograft adapted well to the defect, with no need for fixation. Fibrous connective tissue encapsulated the polyurethane, but no inflammation or giant cell reaction was observed. Acidophilic and basophilic areas were observed inside the micropores of the polyurethane, suggesting cell nuclei. After 90 days, bone repair with a lamellar pattern of organization was observed in the control group. CONCLUSION: The castor oil polyurethane was biocompatible and did not cause inflammation. It may be considered an alternative to fill bone defects.

OBJETIVO: Estudo morfológico comparativo do implante de poliuretana de mamona e enxerto ósseo autógeno em defeito ósseo padrão em osso zigomático de coelhos. MÉTODOS: Vinte e quatro coelhos Nova Zelândia, machos, adultos, foram distribuídos aleatoriamente em dois grupos de 12. Defeitos de 5mm de diâmetro, perenes, foram confeccionados em osso zigomático e preenchidos com discos pré-fabricados de poliuretana no grupo experimento ou osso autógeno extraído da tíbia no grupo controle. Os animais foram sacrificados após 30, 60 e 90 dias e as peças anatômicas foram avaliadas macro e microscopicamente. Foram utilizados os testes de Student, Fisher,qui-quadrado e McNemar para a análise estatística dos resultados. RESULTADOS: A poliuretana e o osso autógeno se adaptaram ao defeito sem necessidade de fixação. Houve formação de tecido conjuntivo fibroso envolvendo a poliuretana, sem reação inflamatória ou presença de células gigantes. Verificaram-se áreas acidófilas e basófilas nos poros do material implantado, sugestivas de núcleos celulares. No grupo controle, observou-se aos 90 dias o reparo ósseo de padrão lamelar clássico. CONCLUSÃO: A poliuretana de mamona foi biocompatível e não causou reação inflamatória deletéria. Pode ser uma alternativa para o preenchimento de defeitos ósseos.

Morphology of autogenous bone graft and castor oil polyurethane in the infraorbital rim of rabbits: a comparative study.

PURPOSE: Morphological study comparing castor oil polyurethane and autogenous bone graft to repair bone defect in zygomatic bone of rabbits. METHODS: Twenty-four adult, male New Zealand rabbits were randomly distributed between two groups of twelve. Bone defects of 5mm in diameter were cut through the zygomatic bone and filled with polyurethane discs in the experimental group or autogenous bone harvested from the tibia in the control group. Animals were sacrificed after 30, 60 or 90 days, and the zygomatic bones were macro- and microscopically analyzed. Student's, Fisher's, chi-squared and McNemar's tests were used for statistical analysis. RESULTS: Both the castor oil polyurethane and the autograft adapted well to the defect, with no need for fixation. Fibrous connective tissue encapsulated the polyurethane, but no inflammation or giant cell reaction was observed. Acidophilic and basophilic areas were observed inside the micropores of the polyurethane, suggesting cell nuclei. After 90 days, bone repair with a lamellar pattern of organization was observed in the control group. CONCLUSION: The castor oil polyurethane was biocompatible and did not cause inflammation. It may be considered an alternative to fill bone defects.