RESUMO
OBJECTIVES: The aim of this work was to determine whether the fixation process with 10% formalin modifies the radiographic optical density of bone. METHODS: Eight rabbit tibiae were placed in separate containers with one of the following fixative solutions: 10% formalin (n = 3), 10% phosphate-buffered formalin (n = 3) or 10% calcium carbonate-buffered formalin (n = 2). Radiographs were obtained at 5 different times: before fixation (time zero), then 1 day, 15 days, 30 days and 90 days following immersion in the fixative solution. Radiographs were scanned and optical density was determined using ImageTool software. RESULTS: There was no significant difference in radiographic optical density among the specimens fixed in 10% formalin (146.60+/-32.44), 10% phosphate-buffered formalin (149.84+/-32.43) and 10% calcium carbonate-buffered formalin (146.61+/-35.92). Regardless of buffering, optical density at time zero was significantly higher than that at 15 days, 30 days and 90 days. However, while optical density at 1 day was significantly higher than that at 30 days and 90 days, it did not differ from that at 15 days. There was also no significant difference in density between 30 days and 90 days (ANOVA, Tukey, at 5% level of significance). CONCLUSION: The radiographic optical density of specimens stored in 10% formalin diminishes with time, irrespective of buffering, which suggests the occurrence of bone demineralization.
Assuntos
Densidade Óssea/efeitos dos fármacos , Fixadores/farmacologia , Formaldeído/farmacologia , Tíbia/diagnóstico por imagem , Animais , Soluções Tampão , Carbonato de Cálcio/administração & dosagem , Densitometria , Diáfises/diagnóstico por imagem , Diáfises/efeitos dos fármacos , Epífises/diagnóstico por imagem , Epífises/efeitos dos fármacos , Formaldeído/administração & dosagem , Fosfatos/administração & dosagem , Coelhos , Radiografia , Tíbia/efeitos dos fármacos , Fatores de Tempo , Fixação de TecidosRESUMO
OBJECTIVES: The purpose of this study was to evaluate the reliability of direct and indirect measurement methods, with a view to standardizing morphometry instruments. METHODS: Dry skulls of 30 New Zealand rabbits were used. Measurements were made with a transparent flexible plastic ruler, an EKG calliper and a digital calliper, as well as with computerized tomography and lateral radiographs for direct and indirect analysis of distances and angles. RESULTS: The different instruments studied showed only partial agreement. CONCLUSIONS: A standardized and reliable direct or indirect morphometry method for the craniofacial skeleton of rabbits still has not been determined.
