ABSTRACT
OBJECTIVE: The aim of this study was to evaluate discoloration of teeth undergoing regenerative endodontic procedures (REPs) using blood clot or platelet-rich fibrin (PRF) as the scaffolds and different calcium silicate-based materials as the intracanal coronal barriers in an ex vivo model. MATERIALS AND METHODS: Forty-eight bovine incisors were prepared and disinfected using 1 mg/mL double antibiotic paste (DAP). The specimens were then randomly divided into 2 groups (n = 24) according to the scaffolds (blood or PRF). After placement of scaffolds each group was divided into 2 subgroups (n = 12) according to the intracanal coronal barriers (ProRoot MTA or Biodentine). The pulp chamber walls were sealed with dentin bonding agent before placement of DAP and before placement of scaffolds. The color changes (∆E) were measured at different steps. The data were analyzed using 2-way analysis of variance. RESULTS: Coronal discoloration induced by DAP was not clinically perceptible (ΔE ≤ 3.3). Regarding the type of the scaffold, coronal discoloration was significantly higher in blood groups compared with PRF groups at the end of REP and after 1 month (p < 0.05). However, no significant difference was found between PRF and blood clot after 6 months (p > 0.05). Considering the type of intracanal coronal barrier, no significant difference existed between ProRoot MTA and Biodentine (p > 0.05). CONCLUSIONS: With sealing the dentinal tubules of pulp chamber with a dentin bonding agent and application of DAP as an intracanal medicament, coronal color change of the teeth following the use of PRF and blood sealed with either ProRoot MTA or Biodentine was not different at 6-month follow-up.
ABSTRACT
OBJECTIVES: This in-vitro study aimed to compare the push-out bond strength of composite to prepared and unprepared intracanal dentin using a 5th generation bonding agent in primary anterior teeth after etching for seven and 15 seconds. MATERIALS AND METHODS: Sixty primary anterior teeth were randomly divided into four groups. In groups one and two, intracanal dentin remained intact while in groups three and four it was prepared using a #5 round bur and low-speed handpiece. Single Bond 2 was used in groups one and three after 15 seconds and in groups two and four after seven seconds of etching with phosphoric acid. After restoring with composite resin and incubation, the specimens were subjected to push-out bond strength test. Data were analyzed using two-way ANOVA and Kaplan Meier curves. RESULTS: The mean bond strength was not significantly different between seven and 15 seconds etching times (P=0.198). Dentin preparation had no significant effect on the mean bond strength (P=0.838). The interaction effect of etching time and dentin preparation was not significant either (P=0.680). CONCLUSIONS: Decreasing the etching time from 15 to seven seconds and preparation of intracanal dentin had no significant effect on push-out bond strength of composite to intracanal dentin of primary anterior teeth.
