Eficacia de un dentífrico con dióxido de silicio obliterante en pacientes con hiperestesia dentinaria / Efficacy of a toothpaste containing precipitated silica particles in patients with dentin hyperesthesia

Introducción: la hiperestesia dentinaria se caracteriza por un dolor intenso y breve asociado a la exposición de estímulos térmicos, táctiles, osmóticos o químicos. De prevalencia creciente, reduce la calidad de vida del paciente. Objetivo: evaluar la eficacia, aceptabilidad y tolerancia de un dentífrico con dióxido de silicio obliterante, nitrato potásico y monofluorofosfato sódico en pacientes con hiperestesia dentinaria. Métodos: estudio observacional y longitudinal (n= 22) en el que se aplicó el dentífrico 3 veces/día durante 28 días. Se realizó una evaluación clínica, antes y después de la aplicación, a las 48 horas, a las 96 horas y los días 7, 14, 21 y 28 del estudio. Se evaluó su eficacia en términos de reducción de la hipersensibilidad dental determinada mediante técnica táctil (escala de calificación verbal) y de chorro de aire (escala de Schiff). En cada visita se valoró la tolerancia del producto. Los pacientes valoraron el grado de hipersensibilidad y su percepción del producto mediante un cuestionario de evaluación subjetiva. El estudio se realizó bajo los principios de Buena Práctica Clínica. Resultados: la hipersensibilidad dental se redujo en todos los puntos temporales del estudio y fue significativa (p< 0,05) a partir del día 5. Esta mejoría fue sostenida y aumentó a medida que avanzó el tratamiento. El día 29 la hipersensibilidad media se redujo en un 85 por ciento respecto al valor basal en todos los pacientes. El 91 por ciento de los participantes opinó que el dentífrico había cumplido sus expectativas. No se observó ninguna reacción adversa derivada del uso del producto. Conclusiones: el dentífrico, administrado 3 veces/día, consiguió una reducción de la hipersensibilidad dental, significativa a partir del día 5, que fue aumentando con el tiempo. El producto presentó muy buena aceptabilidad y tolerancia(AU)

Introduction: dentin hypersensitivity is characterized by sharp pain of short duration associated with exposure to thermal, tactile, osmotic or chemical stimuli. Dentin hypersensitivity is a disorder of growing prevalence which reduces the quality of life of patients. Objective: evaluate the efficacy, acceptability and tolerance of a toothpaste with precipitated silica, potassium nitrate and sodium monofluorophosphate in patients with dentin hypersensitivity. Methods: an observational longitudinal study was conducted (n= 22) in which the toothpaste was applied 3 times a day for 28 days. Clinical assessment was performed before and after the application, at 48 hours, at 96 hours and on days 7, 14, 21 and 28 of the study. Efficacy was evaluated in terms of dental hypersensitivity reduction as determined by tactile (Verbal Rating Scale) and air jet (Schiff scale) techniques. Tolerance to the product was assessed in every visit. Patients ranked the degree of hypersensitivity and their perception of the product by means of a subjective assessment questionnaire. The study complied with Good Clinical Practice principles. Results: areduction was observed in dental hypersensitivity at all time points throughout the study, and it was significant (p< 0,05) as of day 5. This improvement was sustained and increased as treatment progressed. On day 29 mean hypersensitivity had reduced 85 percent with respect to baseline value in all patients. 91 percent of the patients stated that the toothpaste had met their expectations. No adverse reaction attributable to the product was observed. Conclusions: applied 3 times/day, the toothpaste obtained a reduction in dental hypersensitivity, which was significant as of day 5. This improvement increased over time. The product had very good acceptability and tolerance(AU)

Effects of MK-801 and Morphine on Spinal C-Fos Expression during the Development of Neuropathic Pain

The purpose of this study was to investigate the expression of c-fos in the spinal cord during the development of allodynia, induced by peripheral nerve injury. Following tight ligation of the left L5 and L6 spinal nerves of Sprague- Dawley rat, the lumbar spinal cord was postfixed following perfusion. Frontal frozen sections of 40nm were immunostained according to the peroxidase-antiperoxidase method. The allodynic threshold was checked with 8 calibrated von Frey filaments. MK-801 (0.3 mg/kg), morphine (3 mg/kg) and saline (as a placebo) were administered subcutaneously 30 min before, and 24 and 48 hrs after surgery. The tactile threshold decreased below 3 g since 2 days after surgery in the saline and morphine groups, but delayed a little in the MK-801 group. In the superficial layer the number of Fos-like immunoreactive neurones (Fos-LI) peaked at 2 hours and decreased thereafter, and reached normal levels 24 hrs following operation, for all groups. In the deep layer they were biphasic, - peaking at 2 and 24 hrs - in the saline group, but were suppressed in the morphine and MK-801 groups until 7 days following operation. The above discrepancy between the number of Fos-LI and the allodynic threshold showed that central sensitizations are not critically involved in the development of nerve injury induced tactile allodynia.