Comparative evaluation of marginal leakage of glass hybrid restorative material in primary teeth with micro-computed tomography

The aim of this study was to compare the microleakage at the restoration-tooth interface in the use of Equia Forte HT, one of the glass hybrid restorative systems, and Dyract-xp materials from the polyacid modified composite resin group as restorative materials in primary teeth, by using both three-dimensional and cross-sectional dye penetration methods with Micro-CT. Class V cavities were prepared on the buccal and lingual surfaces of 24 extracted lower primary second molars. Equia Forte HT materials were applied to the buccal surfaces of the cavities and Dyract-xp materials were applied to the lingual surfaces. In order to mimic the oral environment, the samples were aged for 1 year in the chewing simulator (Esetron Chewing Simulator), and two layers of nail polish were applied to each sample after aging. Afterwards, the samples were kept in 50% AgNO3 solution to evaluate the microleakage. After the samples were scanned in a Micro-CT device (Skyscan 1275, Bruker, Kontich, Belgium), a three-dimensional volumetric analysis of the microleakage developed at the restoration-tooth interface was performed. In addition, the microleakage levels in the occlusal and gingival areas on 3 cross-sectional images taken from each surface of the samples were determined by scoring with the dye penetration method. In the three-dimensional evaluation, the ratio of the AgNO3 volume leaking from the restoration edges to the total cavity volume was determined numerically, and the Fisher-exact test was used in the statistical evaluation. Student-t test and Mann-Whitney U test were used for the evaluation of leakage in the cross-sectional images taken from the samples. Statistical significance level was accepted as 0.05 in all tests. According to the three-dimensional evaluation, the leakage volume in the Equia Forte HT group was statistically significantly lower than the Dyract-xp group (p<0.001). In dye penetration evaluation, there was no statistically significant difference between Equia Forte HT and Dyract-xp materials in terms of gingival and occlusal leak scores (p>0.05). Based on this study, Equia Forte HT material can be used as an alternative to compomers routinely used in primary tooth restorative treatments and also 3D evaluations can be recommended instead of traditional methods in studies investigating microleakage.