[The effect of curing time and curing method on microleakge of conservative adhesive resin restorations: an in vitro study]

Using the conservative adhesive resin restoration [CAR] in uncooperative children lead to numerous problems because of being time consuming. The purpose of this study was to compare the microleakage of conservative adhesive resin restoration under separate curing and co-curing. In this experimental study, 120 intact premolar teeth were collected and 120 vertical grooves were prepared on them. Then the teeth were divided into four groups: group 1, separated curing of bonding agent, flowable composite and sealant; group 2, co-curing of all materials for 60 seconds; group 3, co-curing of all materials for 40 seconds and group 4, co-curing of all materials for 20 seconds. Then the specimens were thermocycled and immersed in basic fuchsin solution. The teeth were sectioned horizontally and dye penetration was evaluated with stereomicroscope. Date were analyzed using one-way ANOVA and Scheffe test. Mean value of dye penetration in groups 1, 2, 3, and 4 was 1.53 +/- 0.6, 2.06 +/- 0.6, 2.5 +/- 0.7 and 3.53 +/- 0.6, respectively. There was a statistically significant difference between group 1 and the other groups [P=0.0001]. Considering the problems caused by microleakage in conservative resin adhesive restorations, co-curing method should not be used. In the case of using co-curing method, 60 second curing time is suggested for sufficient polymerization

[Evaluation of the microleakage of glass ionomer and resin sealant interface in conservative adhesive restoration [CAR]: an in vitro study]

Glass ionomer is used in conservative adhesive restoration [CAR] in order to release floride. The purpose of this study was to evaluate the microleakage of glass ionomer and fissure sealant interface in in vitro conservative adhesive restorations [CAR]. In this in vitro experimental study, a cavity with diameters of 5 and 3mm and depth of 1mm was prepared in the buccal surface of 21 human's intact premolar teeth. The prepared cavities were filled with glass ionomer and cured. Then another groove with diameter of 5mmx0.5mmx0.5mm was prepared adjacent to and in touch with the first box and filled with fissure sealant and cured. In the lingual surface of each tooth, a cavity with diameter of 3mmx3mm and depth of 1 mm was prepared and filled with flowable composite and cured. Another groove with diameter of 3mmx0.5mm was prepared and filled with fissure sealant and cured. Next, the teeth were subjected to thermolcycling [1000 cycle at 5 to 55[degree sign] c sealant-tooth, and composite-tooth was evaluated with stereomicroscope after being buccolingually sectioned. Results were statistically analysed using the Friedman and Wilcoxon tests. The rate of microleakage between glass-tooth was greater than glass-sealant and also the microleakage between glass-sealant was greater than the microleakage between composite-tooth and composite-sealant. The microleakage between composite-sealant was less than the others. According to the results of this study, it is better to use composite instead of glass ionomer in conservative resin restorations