Análisis de las posibles interfases producidas en la fijación de postes de fibra de vidrio a la estructura dentaria / Analysis of the possible interfaces produced in the fixation of glass fiber posts to the tooth structure

En este trabajo se analizó el comportamiento de las posibles interfases producidas por algunos medios de fijación en la cementación de postes de fibra de vidrio. Para ello recurrimos a dos experimentos: Visualización microscópica de las posibles interfases y el análisis de la penetración de un colorante en la interfase del complejo dentina/ medio de fijación ­ poste de fibra de vidrio. Se conformaron tres grupos de diez unidades experimentales para cada experimento respectivamente. Los materiales con los que se trabajó presentan algún tipo de adhesión a la estructura dentaria. Ellos son el Cemento de Ionómero vítreo convencional, Cemento de resina con adhesivo dentinario y Cemento resinoso autoacondicionante. Con esta investigación se espera poder determinar cuál es el medio de fijación que posibilite la menor interfase en el complejo dentina-medio de fijación- poste de fibra de vidrio (AU)

In this work the behavior of the possible interfaces produced by some fixation media in the cementation of fiberglass poles was analyzed. To do this we used two experiments: Microscopic visualization of the possible interfaces and the analysis of the penetration of a dye in the interface of the dentin complex / fixation medium - glass fiber post. Three groups of ten experimental units were formed for each experiment, respectively. The materials with which they were worked present some type of adhesion to the dental structure. They are conventional Vitreous Ionomer Cement, Resin Cement with Dentin Adhesive and Self-Adhesion Resin Cement. With this research it is expected to be able to determine which is the fixation medium that allows the smallest interface in the dentine complex-fixation medium-fiber glass post (AU)

Effect of experimentally induced occlusal trauma on substance p expression in human dental pulp and periodontal ligament.

INTRODUCTION: The purpose of this study was to quantify the effect of occlusal trauma experimentally induced with occlusal interferences on substance P (SP) expression in healthy human dental pulp and periodontal ligament. METHODS: Twenty-eight human dental pulp and periodontal ligament samples were obtained from healthy premolars in which extraction was indicated for orthodontic reasons. Before extraction, occlusal trauma was induced with experimental occlusal interferences in half of these premolars by placing a resin block over their occlusal surface and submitting patients to chew gum for 30 minutes. The remaining healthy premolars were extracted without occlusal trauma and served as a control group. All dental pulp and periodontal ligament samples were processed, and SP was measured by radioimmunoassay. RESULTS: There was 45% and 120% greater SP expression in dental pulp and periodontal ligament, respectively, of teeth with experimentally induced occlusal trauma. Paired t test showed statistically significant differences for both human dental pulp and periodontal ligament (P = .02 and P < .001, respectively) of teeth submitted to occlusal trauma when compared with control group values. CONCLUSIONS: SP expression in human dental pulp and periodontal ligament increases when teeth are submitted to occlusal trauma experimentally induced with occlusal interferences.

The effect of cavity preparation on substance P expression in human dental pulp.

Substance P (SP) plays an important role during neurogenic inflammation of dental pulp. The purpose of this study was to use a radioimmunoassay for determining the effect of cavity preparation on SP expression in healthy human dental pulp. Ten pulp samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. Deep cavity preparation (<1 mm remaining dentine thickness) was performed before extraction in five of these bicuspids. All samples were processed and I-SP labeled; SP was quantified by competition assay. The results revealed SP expression in all human pulp samples. Mann-Whitney's U test revealed statistically significant higher expression in pulp from teeth where cavity preparation had been performed compared to control values (p < 0.05). These findings suggest that SP is released during common dental procedures (such as cavity preparation) and its expression may have an important clinical significance in terms of experiencing inflammation and pain.