Özet:

Objectives: The purpose of the present study was to evaluate microleakage in Class V cavities pretreated with different KTP (potassium-titanyl-phosphate) laser energy densities before acid etching application. Methods: Thirty-two human premolars were selected for cavity pretreatment. After Class V cavity restorations in buccal and lingual surfaces, teeth were randomly divided into four groups: Group 1: 1 W, 7,1 J/cm2 KTP laser (SMARTLITE D, Deka, Calenzano Firenze, Italy), 37% phosphoric acid (3M ESPE Dental Products, St. Paul, MN, USA) and Single Bond (3M ESPE); Group 2: 1,5 W, 10,7 J/cm2 KTP laser, 37% phosphoric acid and Single Bond; Group 3: 2 W, 14.2 J/cm2 KTP laser, 37% phosphoric acid and Single Bond; Group 4: 37% phosphoric acid and Single Bond. The cavities were restored with composite resin (Filtek Z250, 3M ESPE). The teeth were then thermocycled to 500 cycles, isolated and immersed in 0.5% basic fuchsin for 24 h. After this period, the teeth were rinsed, dried, and sectioned, and microleakage was assessed by dye penetration at the occlusal and gingival surface of the teeth with stereomicroscope (X6). Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests for independent samples, and Wilcoxon test for dependent samples. Results: When microleakage at the enamel margins of all groups were compared, no statistical differences were found (p>0.05). There was a statistically significant difference between Groups 3 and 4 (p<0.05) when the scores of microleakage at the cementum margins of the four groups were compared; however, no other groups had statistically significant differences between them (p>0.05). Conclusions: None of the procedures tested in this study completely eliminated microleakage. KTP laser irradiation prior to acid etching to dentin following cavity preparation reduced mean microleakage values compared with acid etching alone at the enamel and the cementum margins. Key words: Class V cavity, KTP laser, microleakage

Anahtar Kelimeler: