Influence of application techniques on contact formation and voids in anterior resin composite restorations

This study evaluated the influence of three different application techniques on contact formation and voids in anterior resin composite restorations. Artificial ivorine teeth were randomly assigned to three experimental groups, with 20 specimens in each group. One operator performed all restorations using the Teflon tape, pull-through, or bioclear matrix technique. The treatment time required for each restoration was recorded. An examiner blinded to the treatment group performed the visual evaluation of six criteria, including proper contact formation. The restored teeth were cut to yield a total of 180 sections for microscopic evaluation. The Kruskal-Wallis procedure was performed to evaluate the significance of treatment time, number of voids, percent porosity area, and void diameter. There were significant differences in treatment time among the three groups (p<0.05). The bioclear matrix technique required the least time for the treatment of one diastema closure (p<0.05). The Teflon tape technique resulted in proper contact formation in 80% of specimens, a rate that was significantly lower than that associated with the pull-through and bioclear matrix techniques (p<0.05). Out of 540 imaging areas 160 images were free of voids. The number of voids and the percent porosity area were not significantly different among the three techniques (p>0.05). However, the mean void diameter was greater with the bioclear matrix technique compared to the other two techniques (p<0.05).