Résumé
Abstract The objective of this study was to evaluate the effects of diode laser and a desensitizing dentifrice on dentin permeability. Fifty-two root dentin fragments were obtained (5 × 5mm) and treated with 24% EDTA gel. The samples were divided into 4 groups (n = 13): G1, control (no treatment); G2, diode laser (λ = 908 nm, 1.5 W, continuous mode, 20s); G3, application of abrasive dentifrice for 1 minute (Elmex Sensitive Professional (International Gaba); and G4, application of abrasive dentifrice for 1 minute followed by irradiation with diode laser. Ten samples per group were immersed in 2% methylene blue solution for 4h. The specimens were washed, longitudinally sectioned, observed under optical microscopy, photographed and assessed based on the degree of dye leakage. The remaining samples were observed under scanning electron microscopy (SEM). The leakage data were subjected to ANOVA test, followed by Tukey's t-test (α = 5%). Groups 2, 3 and 4 showed less dye penetration than the control group (p < 0.05), but were similar among each other. SEM images showed that dentinal tubules were open in G1, and fused and occluded in G2. Group 3 showed dentinal tubules that were occluded by the metal ions from the toothpaste. G4 presented similar characteristics to G3, and the presence of fused dentin. The diode laser and the dentifrice were effective in reducing dentinal permeability, and the combination of the two treatments did not show better results than either one used alone.
Sujets)
Animaux , Bovins , Racine dentaire/effets des médicaments et des substances chimiques , Dentifrices/composition chimique , Dentine/effets des médicaments et des substances chimiques , Perméabilité de la dentine/effets des médicaments et des substances chimiques , Hypersensibilité dentinaire/traitement médicamenteux , Agents désensibilisants dentinaires/composition chimique , Propriétés de surface/effets des médicaments et des substances chimiques , Propriétés de surface/effets des radiations , Facteurs temps , Racine dentaire/effets des radiations , Microscopie électronique à balayage , Répartition aléatoire , Reproductibilité des résultats , Dentine/effets des radiations , Perméabilité de la dentine/effets des radiations , Thérapie laser/méthodes , Lasers à semiconducteur/usage thérapeutiqueRésumé
O objetivo do presente estudo foi avaliar a permeabilidade da dentina, através da infiltraçäo de corante em raízes de dentes humanos unirradiculares extraídos, submetidas à irradiaçäo de laser Nd: YAG sob densidade energética de 100 mJ, potência de 1,5 W, freqüência de 15 Hz em 10 s, posteriormente ao preparo do canal, considerando-se também as raízes nas quais o preparo químico-cirúrgico näo foi executado. Os resultados mostraram que no grupo em que se realizou o preparo do canal, seguido da irradiaçäo de laser, houve menores taxas de infiltraçäo de corante - estatisticamente significativas - quando comparadas ao grupo onde o preparo do canal foi realizado, porém o laser näo irradiado