ABSTRACT
Context: Osteoporosis is a skeletal disorder characterized by low bone mass and microarchitectural deterioration of bone tissue. It may affect the craniomaxillofacial complex and result in less bone-implant contact. Aims: The objective of this study was to measure the endosseous integration of titanium implants using the removal torque test in low-mineral density experimental animal models. Materials and Methods: Thirty female New Zealand white rabbits were divided into two groups: control (n=14), sham-operated; and test (n=16), ovariectomized. All animals received 2.2 mm Χ 4.0 mm titanium implants in the right tibia, 120 days after ovariectomy or sham surgery. Animals were killed at 7 and 14 weeks of postimplant insertion, when implants were removed by reverse torque rotation using a digital torque meter. Statistical analysis used was Student's t-test. Results and Conclusion: At the 7-week period, the mean torque values for the control and test groups were 11.6 Ncm and 10.4 Ncm, respectively, with no statistical significance. Implant removal torque analysis showed statistically lower values (P<0.05) for the test group at the 14-week period (control=16.7 Ncm and test=9.7 Ncm). The results of this study indicate that hormonal privacy compromise implants biomechanical performance.
Subject(s)
Absorptiometry, Photon , Animals , Biomechanical Phenomena , Bone Density/physiology , Bone Diseases, Metabolic/physiopathology , Dental Implants , Dental Materials/chemistry , Device Removal , Disease Models, Animal , Female , Osseointegration/physiology , Osteoporosis/physiopathology , Ovariectomy , Rabbits , Random Allocation , Stress, Mechanical , Tibia/surgery , Time Factors , Titanium/chemistry , TorqueABSTRACT
Os autores relatam os resultados observados em pesquisa de D.Q., realizada em uma populaçao de 517 R.N. da Maternidade de HEUCS, no período de outubro de 1991 até maio de 1992, com o intuito de comprovar a suspeita de que a populaçao de Caxias do Sul poderia ser mais afetada em virtude de ser, na sua maioria, integrada por descendentes de habitantes de uma área dita endêmica. Foram detectadas D.Q. em 3 dos 517 R.N. (0,58 por cento) determinando uma incidência significativamente alta da patologia, da ordem de 1 para cada 172 nascimentos. Além dessa incidência, relatam ainda o relacionamento dessa entidade com fatores conhecidamente implicados na sua gênese, tais como o sexo e a apresentaçao fetal.