Influence of etching in microleakage of different modified polyacid resins

Abstract

The aim of this study was to evaluate the microleakage of two modified polyacid resins, Dyract AP (DY) and F-2000 (F2) associated or not to the total etching technique (ET) with 37% phosphoric acid. Thirty-two human molar teeth were used which after disinfection, were stored in physiologic serum. Each tooth received two standardi- zed Class V cavities (4mm x 4mm x 2 mm), all of them with margins in cementum and enamel. The teeth were divided into 4 groups (08 teeth in each), and restored according to the manufacturer´s instructions divided into the following groups: 1 - DY + Prime&Bond 2.1 with ET; 2 - DY + Prime&Bond 2.1 ET; 3 - F2 + Single-Bond with ET and 4- F2 + Single-Bond without ET. The restored teeth were stored for 07 days, thermocycled (500 cycles, 5ºC - 50ºC, 15s each bath) and then in- serted into 5% methilene blue. After 24 hours they were washed and sectioned in a buccolingual direction. Each resto- ration was evaluated by 02 examiners, being attributed values from 00 to 03, through stereomicroscope, in the gingival and occlusal walls. The scores were submitted to sta- tistical analysis (Kruskall-Wallis) test, at 1% significance level and Mann-Whitney, at 5% signifiance level. Based on this study, the authors concluded that the acid etching with 37% phosphoric acid only in! uenced the results in the enamel wall (occlusal). Key words: dental materials; microleakage; acid etching.