Abstract
BACKGROUND: Root canal treatment requires thorough chemomechanical debridement and three-dimensional obturation for a fluid-tight seal. However, complete eradication of microbial biofilms is difficult due to the complexities of root canal anatomy, limiting irrigant penetration. Photodynamic therapy plays a key role in enhancing antimicrobial efficacy. Bioceramic sealers are commonly used due to their biocompatibility, antibacterial properties, and bioactivity, though their high alkalinity can damage exposed collagen, leading to tooth fracture. Cross-linking of collagen can slow biodegradation and improve dentin strength. Medicinal plants, like Curcuma longa, offer antimicrobial and immune-modulatory properties, with its extract curcumin also serving as a photosensitizer and cross-linking agent. The study explores curcumin's ability to combat Enterococcus faecalis biofilms and improve collagen matrix integrity in root dentin. AIM AND OBJECTIVE: This study aimed to examine the antibiofilm efficacy of collagen cross‑linking agents and their effects on the integrity of the radicular collagen matrix. METHODOLOGY: Thirty extracted single-rooted human teeth were decoronated to standardize the root length to 12 mm and then prepared using ProTaper rotary files (Dentsply Maillefer, Ballaigues, Switzerland) up to size F3. The specimens were randomly divided into three groups based on the irrigant used (curcumin, chlorhexidine, and saline). Each group was further subdivided based on the evaluation method. In one set of samples, Enterococcus faecalis was inoculated into the canals and incubated for 21 days. Following disinfection with the respective irrigant photoactivated with a diode laser, bacterial quantification was performed using real-time polymerase chain reaction. Another set of samples was obturated after surface treatment with the same irrigants and stored in artificial saliva. The release of hydroxyproline, an indicator of collagen degradation, was measured spectrophotometrically after 21 days. Data were statistically analyzed using ANOVA and Tukey's post hoc test with a significance level set at p < 0.05. RESULTS: Curcumin with light activation (Group 1A) demonstrated the highest cycle threshold values (38.20 ± 1.34), indicating superior bacterial reduction, followed by chlorhexidine (25.06 ± 3.11) and saline. E. faecalis counts were lowest in Group 1A (210.60 ± 46.11). Hydroxyproline release was minimal in curcumin-treated samples (0.04 ± 0.02), suggesting better collagen preservation, while the control showed the highest release (1.18 ± 0.28). Statistical analysis confirmed significant differences among groups (p < 0.05). CONCLUSION: Curcumin, particularly when photoactivated, exhibits potent antibiofilm effects and protects collagen in root dentin, making it a promising adjunct in endodontic therapy.