Use of Rose Bengal, methylene blue and curcumin photosensitizers activated using light emitting diode on post space disinfection bonded to fiber post: an assessment of extrusion bond strength

Objectives: To evaluate the effect of Rose Bengal (RB), methylene blue (MB) and curcumin used as a canal disinfectant on the extrusion bond strength (EBS) of FRCP (fiber reinforced composite resin) with canal dentin. Methods: The present invitro study was completed in 90 days approved by Riyadh Elm University. Forty premolars were extracted disinfected and decoronated. Mechanochemical preparation was done of canal space using 10k file widening canals sequentially with a 25K file with constant saline irrigation. Canal was dried condensed with gutta percha and sealer. Post space was prepared using peso reamer. Based on canal disinfection samples were divided into four groups. Group-1 MBP+17% EDTA, Group-2 RBP +17% EDTA, Group-3 Curcumin+17% EDTA and Group-4 5.25% NaOCl +17% EDTA. Following disinfection, the canal space of all specimens was washed with 17% EDTA for 120 sec. Post was cemented in canal space and cured. Specimens were placed on Universal testing machine (UTM) for EBS. The type of bond failure was evaluated using stereomicroscope. ANOVA and Tukey multiple comparison test was used to compare means. Results: Cervical third of Group-3 in which samples were disinfected with CP+17% EDTA displayed the maximum EBS (8.69±1.32 MPa). Whereas, the lowest EBS (3.30±0.54 MPa) was exhibited by the apical third of Group-4, where 5.25% NaOCl +17% EDTA was used as a canal disinfectant. The intragroup comparison demonstrated a declining trend of EBS from cervical to apical third in all investigated groups. Conclusion: Root canal dentin treated with different PS (MBP, CP, and RBP) demonstrated better EBS than the conventional disinfecting regime (NaOCl +17% EDTA). CP and RBP displayed better EBS than MBP. (author)