Degree of conversion of resin cement with varying methacrylate compositions used to cement fiber dowels: A Raman spectroscopy study.

STATEMENT OF PROBLEM: Studies on the degree of conversion of dental cement in relation to the number of methacrylate components are lacking.

PURPOSE: The purpose of this in vitro study was to evaluate the degree of conversion of single- and multicomponent methacrylate-containing dental cements around opaque and translucent fiber dowels at varying depths.

MATERIAL AND METHODS: Teeth were prepared for standard endodontic therapy, and a dowel space was created. Opaque and translucent fiber dowels consisting of Aestheti-Plus (AP) and FiberKleer were cemented with 4 methacrylate (MA)-containing cements, including RelyX U100 (R), which contains TEGDMA; Duolink (D), which contains TEGDMA and BisGMA; and Variolink N LC (V) and Breeze (B), which contain TEGDMA, BisGMA, and UDMA. Light-emitting diode polymerization was performed for 60 seconds. The specimens were immediately cut into halves and measured within the first hour at depths of 1, 3, and 5 mm using Raman spectroscopy, and the degree of conversion (DC) of resin cement was calculated. Data were analyzed using 3-way ANOVA and the Tukey multiple comparison test (α=.05).

RESULTS: The measured dowel regions were not significantly different at various depths (P=.10). The dowel and cement types significantly influenced the degree of conversion of the cement (P<.05). The V and B cements exhibited a higher DC than D and R cements. With AP dowels, the DC of cement D was lower than that of the V, B, and R cements.

CONCLUSIONS: Within the limitations of this in vitro study, the degrees of conversion of the tested resin cements were not affected by the tested dowel depths. Higher DC was found in cement with more than 2 types of flexible MA. Opaque dowels produced a lower DC than translucent dowels.