Evaluation and Comparison of the Antimicrobial Efficacy and Sealing Ability of Fish Bone Paste with Calcium Hydroxide Paste as Pulp Capping Material: A Research Protocol for an In-vitro Study

Introduction: Indirect Pulp Capping (IPC) is defined as a procedure wherein a small amount of carious dentin is retained in deep areas of the cavity to avoid exposure of pulp, followed by placement of a suitable medicament and restorative material that seals off the carious dentin and encourages pulp recovery. Calcium hydroxide has been the gold standard for pulp capping material due to its exceptional biocompatibility, antibacterial properties, and ability to encourage the formation of reparative dentin. Fish Bone (FB) powder is a naturally occurring substance that has shown promise as a pulp capping material. It contains a lot of calcium, phosphates, and other bioactive substances that could help with dentinogenesis and repair. To ascertain whether it can be a suitable substitute for or addition to calcium hydroxide, its antimicrobial activity and sealing capacity must be thoroughly assessed. Need of the study: The current study can demonstrate the antimicrobial effectiveness and sealing ability of FB paste as a pulp capping material. Aim: To evaluate and compare the anti-microbial efficacy and sealing ability of FB paste with calcium hydroxide paste as pulp capping materials through an in-vitro study. Materials and Methods: An in-vitro study will be conducted in Department of Paediatric and Preventive Dentistry at Sharad Pawar Dental College, Wardha, Maharashtra, India, from May 2025 to December 2025, in which FB paste and calcium hydroxide paste will be prepared to evaluate and compare the anti-microbial efficacy and sealing ability for an in-vitro investigation in the Department of Paediatric and Preventive Dentistry at Sharad Pawar Dental College, Wardha, Maharashtra, India. The agar diffusion method will be used to evaluate the antibacterial efficacy of calcium hydroxide paste and FB paste against Enterococcus faecalis. After being cultivated in brain-heart infusion broth for the entire night, the E. faecalis stock culture will be injected onto Muller-Hinton agar plates. A copper puncher will be used to create wells on the plates that are 4 mm in diameter and 4 mm deep. The wells will then be promptly filled with freshly created, specially designed test materials. After being incubated at 37°C for 24 and 72 hours, the agar plates will be evaluated. The diameter of the zone of inhibition will be measured in millimetres after incubation. The dye penetration method will be used to evaluate the sealing ability of calcium hydroxide paste and FB paste. After preparing a Class I cavity, pulp capping material consisting of calcium hydroxide and powdered FBs will be inserted into the cavity. All samples will undergo 500 thermocycling cycles with 60-second dwell intervals to replicate dental conditions, and each tooth will receive two coats of nail polish with a 1 mm margin around the restoration border. Following a 24-hour incubation period at room temperature in 5% methylene blue dye, the samples will be rinsed under running water and then sectioned mesiodistally using a diamond disk with water cooling. To assess the material's capacity to seal, the degree of dye penetration will be evaluated. The Chi-square test, student paired and unpaired t-test, One-way Analysis of Variance (ANOVA), and Tukey test will all be used in the statistical analysis.