RESUMEN
Given its increasing incidence and serious complications, osteoporosis requires safe and effective long-term treatment. Strontium ranelate (SR), a new anti-osteoporotic treatment with a unique mode of action, has been investigated in the SOTI (Spinal Osteoporosis Therapeutic Intervention) and the TROPOS (Treatment of Peripheral Osteoporosis) trials, two major 3-year multinational placebo-controlled phase 3 randomized clinical trials. Unlike antiresorptive agents, SR produced steady and significant bone mineral density increases that correlated directly with decreases in vertebral and hip fracture risk. The safety profile of SR was almost similar to placebo in both trials. A slight but significant increased risk of thromboembolism events was noted from the pooled phase 3 studies data. However, this increased was not found in a large retrospective observational study. Thus, SR demonstrates broad spectrum safety and efficacy in reducing the risks of both vertebral and nonvertebral (including hip) fractures in a wide variety of patients, and should be considered as a first-line option to treat women at risk of osteoporotic fractures, whatever their age, the severity of the disease, and their risk factors.
Asunto(s)
Conservadores de la Densidad Ósea/uso terapéutico , Densidad Ósea/efectos de los fármacos , Fracturas Óseas/prevención & control , Osteoporosis Posmenopáusica/tratamiento farmacológico , Estroncio/uso terapéutico , Anciano , Anciano de 80 o más Años , Ensayos Clínicos Fase III como Asunto , Femenino , Fracturas Óseas/epidemiología , Fracturas Óseas/etiología , Humanos , Persona de Mediana Edad , Osteoporosis Posmenopáusica/complicaciones , Ensayos Clínicos Controlados Aleatorios como Asunto , Estroncio/normasRESUMEN
The creep of microspecimens of posterior dental composites was studied using a torsional creep apparatus. Shear stresses were maintained for 3 h and recovery was followed for 50 h. Creep curves were obtained at 21, 37, and 50 degrees C and four torque levels. The effect of conditioning the specimens in water up to 8 weeks was studied. The posterior composites exhibited linear viscoelastic behavior at low deformations. They had higher shear moduli and greater resistance to creep than conventional and microfilled composites. In aging experiments, maximum shear moduli occurred when specimens were 48 h to 1 week old. Subsequent softening was attributed to water absorption. Residual strain was highest when the composites were stressed within 24 h of initiating polymerization. Residual strain was very low in specimens 48 h to 8 weeks of age.
