The effect of laser preparation on microleakage of glass ionomer-based restoratives

Objectives: To evaluate the effect of laser preparation on microleakage of different glass ionomer-based materials used in root surface cavities.
Methods: Thirty-six extracted sound human third molars were used for the study. The teeth were randomly divided into two cavity preparation methods; GroupI-bur, Group II- laser (n=18). A total of seventy-two class 5 cavities were prepared on both buccal and lingual root surfaces 1mm below the cementoenamel junction. One group prepared with diamond bur the other prepared with Er;Cr:YSGG laser. Each group were then randomly subdivided into three subgroups according to different glass ionomer-based restorative materials; A)zirconomer, B)EQUIA and C)Riva self-cure (n=12). After storage of restored teeth in distilled water for 24 hours, they were termocycled (x10000; 5-55⁰C)and then immersed in basic fuchsin (0.5%) for 24h. The teeth were embedded in acrylic blocks and sectioned longitudinally into three sections using a water-cooled diamond saw in a sectioning machine. The microleakage evaluation was performed by two calibrated examiner under 20x magnification in light microscope. The data were analyzed using Kruskal Wallis and Mann Whitney U tests (p<0.05).
Results: For each cavity preparation method, no significant differences in microleakage were found between the glass ionomer materials(p>0.05). When comparing cavity preparation methods within each restorative materials, significant differences were observed only in Riva self-cure (p<0.05). Bur prepared cavities showed less mikroleakage in Riva self-cure group.
Conclusions: Different types of glass ionomer-based restoratives showed similar leakage values on root surface in either bur- or laser-prepared cavities. Riva self-cure exhibited more leakage in laser-prepared cavities than cavities prepared with bur. Within the limitations of this study, it can be concluded that; bur preparation might be preferrable over laser preparation in root surface cavities restored with riva.