Marginal leakage in class V cavities pretreated with different laser energy densities.
The purpose of the present study was to evaluate in vitro the degree of marginal leakage in Class V cavities involving the cementoenamel junction. Cavities were 4 mm wide and 2 mm deep. The specimens received dentin pretreatment (37% phosphoric acid) followed by the Single Bond (3M) adhesive system application. The 40 specimens were then divided into four groups: Group 1 (control); Group 2 (Nd:YAG laser at 120 mJ/pulse, frequency of 10 Hz, power of 1.2 W); Group 3 (Nd:YAG laser at 140 mJ/pulse, frequency of 10 Hz, power of 1.4 W); Group 4 (Nd:YAG laser at 160 mJ/pulse, frequency of 10 Hz, power of 1.6 W). The cavities were restored with Z100 composite resin (3M) and light cured at 300-600 mW/cm2 light intensity. Specimens were thermocycled to 500 cycles from 2-50 degrees C. After that, they were dried and sealed with nail varnish, respecting 1 mm around the restorations, and immersed in 0.5% methylene blue solution for 4 h. After this period, the teeth were rinsed, dried, sectioned, and analyzed in a stereoscopic loupe. The highest leakage scores were considered for each specimen. The results were statistically analyzed by the analysis of variance (ANOVA) - Kruskal-Wallis test to the 5% level. For both the enamel and cementum, there was a decrease in marginal leakage with the application of laser energy; no significant differences were observed for Groups 2, 3, and 4. The results also showed a smaller tendency to marginal leakage on the cementum than on the enamel.
Ribeiro
Carolina Ferraz
CF
Department of Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), São José dos Campos, Brazil. carolferrazunesp@hotmail.com
Anido
Andrea Anido
AA
Rauscher
Flávia Cristo
FC
Yui
Karen Cristina Kazue
KC
Gonçalves
Sérgio Eduardo de Paiva
SE
D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D003737:Dental Cavity Preparation / Q000379:methods*; D003763:Dental Leakage / Q000175:diagnosis / Q000517:prevention & control*; D053685:Laser Therapy; D019237:Tooth Cervix