Light curing effect on the microhardness of dual cure resin cements used for cementation of intra-radicular posts

Manoela F. Francisconi, Camila M. Machado, Luiz F. Pegoraro, Ricardo M. Carvalho, Ernesto B. B. Jalkh, Thiago A. Pegoraro, Ilana S. Ramalho e Estevam A. Bonfante

Introduction: Insufficient curing of dual cure cements used for cementation of intra-radicular posts may compromise restorative retention system, which could lead to restoration failure. Objective: This study aimed at assessing the microhardness of dual cure resin cements used for glass fiber posts (DT Light PostTM) cementation, whether subjected or not to a light curing source, according to the different root thirds. Methods: Forty roots of bovine incisors were selected and divided into eight groups, according to the cement being used: G1/G5 = PanaviaTM; G2/G6 = Variolink IITM; G3/G7 = RelyX UnicemTM; G4/G8 = Duo-linkTM. G1 to G4 were light-cured; whereas G5 to G8 were not. The roots were longitudinally sectioned and submitted to microhardness tests. Data were tested for significant differences by three-way ANOVA and Tukey’s tests (p < 0.05). Results: Microhardness values, mean (standard deviation), obtained for cervical, middle and apical thirds were, respectively: G1 = 56,00 (8,35), 51,72 (11,39), 48,28 (7,45); G2 = 42,94 (4,92), 37,46 (6,23), 35,28 (5,96); G3 = 46,56 (3,89), 48,12 (4,88), 51,48 (5,74); G4 = 42,24 (2,85), 40,60 (5,76), 39,24 (3,84); G5 = 39,47 (5,99), 37,33 (3,15), 40,45 (6,41); G6 = 36,72 (1,70), 36,78 (3,05), 35,25 (0,59); G7 = 42,96 (6,78), 43,12 (7,56), 42,40 (4,21); G8 = 37,78 (7,11), 34,88 (6,30), 34,84 (6,03). Light cured specimens showed higher microhardness values; PanaviaTM and RelyX UnicemTM cements presented significantly higher values compared to others (ANOVA/Tukey, p < 0.05).There were no differences among groups (ANOVA, p > 0.05). Conclusions: Light curing positively influenced the results, regardless of the root section evaluated.

Keywords: Resin cements. Dental posts. Hardness tests.

How to cite: Francisconi MF, Machado CM, Pegoraro LF, Carvalho RM, Jalkh EBB, Pegoraro TA, Ramalho IS, Bonfante EA. Light curing effect on the microhardness of dual cure resin cements used for cementation of intra-radicular posts. J Clin Dent Res. 2016 jan-mar;13(1):98-106. DOI: http://dx.doi.org/10.14436/2447-911x.13.1.098-106.oar

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