ABSTRACT
OBJECTIVE: The present lab-based investigation aimed at evaluating the canal disinfectants using photodynamic therapy (PDT) using different photosensitizers, conventional NaOCl, a mixture of doxycycline, citric acid, and a detergent (MTAD) and their impact on the bond strength of glass fiber post to radicular dentin. MATERIALS AND METHODS: Forty extracted human premolars were gathered and disinfected. The decoration was performed up to the cementoenamel junction. Using the crown down technique cleaning of the canal was done following rinse with distilled water. All canals were dried with paper points and obturated with gutta-percha. Post space was prepared using peso reamers and samples were randomly allocated into four groups following different disinfection regimes: Group 1 - Methylene blue photosensitizer (MBP) + MTAD; Group 2 - RBP (Rose Bengal photosensitizer) + MTAD; Group 3 - CP (curcumin photosensitizer) + MTAD and Group 4 - 2.25% NaOCl + MTAD (control). Following disinfection, the canals were dried and the post was placed and cemented within the canal. Samples were dissected at coronal, middle, and apical third and placed in a universal testing machine for push-out bond strength (PBS). Debonded surfaces were evaluated for failure modes. PBS was examined using a one-way analysis of variance (ANOVA). The means of PBS were compared using Tukey multiple comparison tests with a significance threshold of (p<0.05). RESULTS: Group 3 canals disinfected with CP and MTAD had the highest PBS at two levels: cervical (9.57±1.21 MPa), middle (6.37±0.79 MPa), and group 2 canal space disinfected by RBP and MTAD had the maximum PBS in apical portion (5.35±0.42 MPa). No significant difference at all root levels between group 2 (RBP + MTAD) and group 3 (p>0.05). Canal irrigation with group 1 (MBP + MTAD) and group 4 control (2.25% NaOCl + MTAD) exhibited comparable PBS at all three levels of the root. CONCLUSIONS: CP, MTAD, RBP and MTAD for canal disinfection and bonding of glass fiber post to radicular dentin demonstrated comparable bond values at all three root levels and can be recommended in clinical settings after further investigations.
