Comparative Evaluation of Push-Out Bond Strength of Conventional Mineral Trioxide Aggregate, Biodentine, a Modified Mineral Trioxide Aggregate, and Two Novel Antibacterial-Enhanced Mineral Trioxide Aggregates

Abstract

Background The challenges associated with incorporating antimicrobial agents, such as the potential diminishment of the cement's physical properties, highlight the need for comprehensive evaluations. Balancing antimicrobial efficacy with the maintenance of structural integrity is a crucial aspect of material development. The acknowledgment of cytotoxic properties associated with tricalcium aluminate, a major constituent in conventional mineral trioxide aggregate (MTA), is critical in terms of long-term evaluation of treatment procedures. The primary focus of the push-out test is to evaluate the resistance of the tested material to dislodgement. Greater push-out strength implies stronger adhesion between the tested material and the tooth surface. Aim This study aims to evaluate the push-out bond strength of two antibacterial-enhanced MTAs with conventional MTA and Biodentine. Material and methods A total of five materials were tested: a) modified MTA, b) doxycycline-enhanced MTA, c) metronidazole-enhanced MTA, d) conventional MTA, and e) Biodentine. All the materials were mixed based on a predetermined powder:liquid ratio and then carried using a plastic instrument to the desired experimental design. Single-rooted permanent teeth, preferably incisors, were used in the present study. Teeth were embedded vertically in a rubber mold, and sectioning of the tooth was performed. A single operator instrumented the canal space in each slice using Gates-Glidden burs, and the mixed cements were placed in the respective groups and stored for 72 hours. A push-out test was carried out using a universal testing machine. Following the bond failure, the slices were examined under a stereomicroscope to determine the nature of the bond failure. The collected data was subjected to a one-way analysis of variance test, post hoc test, and chi-square test for statistical analysis. Results The mean push-out bond strength was found to be the highest for Biodentine (43.25 ± 0.62 megapascals (MPa)), followed by doxycycline- and metronidazole-enhanced MTAs (39.54 ± 0.65 MPa and 39.29 ± 0.16 MPa, respectively), modified MTA formulation (37.75 ± 0.73 MPa), and the lowest for conventional MTA (25.93 ± 0.7 MPa). Conventional MTA samples had an adhesive failure (89.4%), while Biodentine samples had a cohesive failure (80.3%). Mixed failures were noticed with the samples containing modified MTA formulation (71.3%), doxycycline-enhanced MTA (76.6%), and metronidazole-enhanced MTA (78.0%). Conclusion Despite not surpassing Biodentine in bond strength, antibacterial-enhanced MTAs are considered potential alternatives to conventional MTA in day-to-day clinical practice.

Keywords: biodentine; doxycycline; metronidazole; mineral trioxide aggregate; pushout bond strength.

Figure 1. Representative images of the scanning electron microscopic analysis of the predominantly noticed bond failures with the materials tested. A: Mixed failure in group 1 samples; B: Mixed failure in group 2 samples; C: Mixed failure in group 3 samples; D: Adhesive failure in group 4 samples; E: Cohesive failure in group 5 samples, respectively.