An in vitro evaluation of various natural intracanal medicaments for the effect of hardness on tooth structure and antimicrobial efficacy

Aim: This study aimed to evaluate the mechanical and antibacterial properties of therapeutic seed extracts – chia, flax, guava, and papaya – in comparison to calcium hydroxide for potential intracanal application in endodontics. Methodology: A total of 150 extracted single-rooted teeth were cleaned, decoronated, and standardized to 12 mm. After biomechanical preparation, samples were sterilized and divided into two groups (A and B), each with five subgroups: calcium hydroxide, chia, papaya, flax, and guava seed extracts. Microbial inoculation was performed using polymicrobial samples from infected root canals, followed by incubation for 7–14 days. Group A samples were sectioned horizontally (3 mm × 3 mm × 2 mm), embedded in acrylic, treated with respective medicaments, and analyzed using confocal microscopy after staining with live/dead bacterial stain. Group B samples were sectioned vertically (4 mm × 2 mm × 2 mm), treated, and subjected to microhardness testing. Seed-based medicaments were prepared by sun-drying, powdering, autoclaving, and mixing with propylene glycol to achieve a homogeneous paste. Results: Chia seed extract showed the highest antimicrobial activity and dentin reinforcement, comparable to calcium hydroxide. Papaya and guava seeds exhibited moderate antibacterial efficacy. Flaxseed demonstrated the lowest performance in both aspects. Calcium hydroxide was effective but did not surpass some natural extracts in mechanical enhancement. Conclusion: Chia and papaya seed extracts present promising alternatives to calcium hydroxide, offering dual functionality – antibacterial efficacy and mechanical reinforcement. These findings support the integration of natural agents in endodontic treatment. Further in vivo and formulation studies are recommended to validate their clinical use.