Interactions between resin-based temporary materials and immediate dentin sealing

Bonded indirect restorations require two appointments: one for provisional treatment and one for luting with resin cement and dentin bonding agents (DBA). The DBA layer may be accomplished during a delayed dentin sealing (DDS) step following the provisional phase or an immediate dentin sealing (IDS) step after tooth preparation and during final luting procedures. The purpose of this study was to compare the effect of resin-based provisional material (RBPM) on the tensile bond strength to human dentin developed using DDS and IDS procedures. Flat dentin surfaces were prepared on 48 molars for microtensile testing. The specimens were restored using a 3-step etch-and-rinse DBA and composite resin (CR). A set of control specimens (G1) was directly restored using DBA and CR, while the remaining samples were treated using a provisional restoration procedure for 2?weeks: DDS?+?acrylic resin (AR)?+?calcium hydroxide cement (CHC) (group G2), DDS?+?AR?+?eugenol-free cement (G3), DDS?+?RBPM (G4), IDS?+?glycerin?+?RBPM (G5), or IDS?+?RBPM (G6). After storage of the final restoration in water for 24?h, the specimens were serially sectioned to obtain bonded sticks 0.8?mm² in area. The tensile strength was tested at a crosshead speed of 0.5?mm/min. The results were analyzed using ANOVA and Tukey’s post hoc tests (α?=?0.05). The mean (standard-deviation) bond strengths for groups G1–G6 were 42.18 (±2.63); 40.14 (±3.46); 37.77 (±0.93); 37.16 (±2.61); 34.11 (±1.08) and 23.79 (±0.49) MPa. The mean bond strength of group G6 was significantly lower (p?<?0.05), suggesting that adhesion to dentin is influenced by use of RBPM with IDS prior to placement of a definitive restoration.