Objectives: The aim of this study was to evaluate the effect of cure mode of the adhesive and seating pressure technique on the microtensile bond strength of dual cure resin cements to perfused dentin.
Methods: Occlusal enamel of 32 extracted human third molars were removed using 180 grit SiC paper and smear layer on the mid coronal dentin was standardized using 600 SiC. Teeth were randomly divided into 2 groups according to the resin cement-adhesive combination (AdheSe-Variolink II, Ivoclar/Vivadent; Protect Bond-Clearfil Esthetic Cement, Kuraray). Each group was further subdivided into 4 groups according to the type of the curing mode of the adhesive (cured; uncured) and according to the seating pressure technique (40N/30 sec; 40 N/110 sec). Composite onleys (Filtek Z 250; 3M ESPE) 3mm in thickness and 9 mm in diameter were luted with the dual cure resin cements adhesive combinations to 15 cm/H2O perfused dentin. After storage in distilled water at 37oC for 24 h, microtensile bond strength (MPa) was evaluated using Bencor Multi Testing device attached to a universal testing machine (Instron). Data were analyzed using Mann-Whitney-U test.
Results: Different superscript letters in the same column and different capital superscript letters in the same row indicate significant differences (p<0.05).
Cure mode | Pressure technique | AdheSe-Variolink II | Protect Bond-Clearfil Esthetic Cement | n |
uncured | 40 N/30 sec | 36,69±8,39 a,b,A | 20,64±8,52 a,B | 22 |
cured | 40 N/30 sec | 29,84±12,55 a,b,A | 32,63±9,76 b,A | 22 |
uncured | 40 N/110 sec | 27,53±8,86 a,A | 24,47±10,59 a,c,A | 22 |
cured | 40 N/110 sec | 35,25±14,95 b,A | 29,17±9,4 b,c,A | 22 |
Conclusions: Curing of the adhesive may improve the microtensile bond strength to dentin of Clearfil Esthetic Cement in combination with Protect Bond and Variolink II with AdheSe. Pressure technique (30 versus 110 sec) did not affect bonding of both resin cements to dentin in between the cured and uncured groups.