Sealing Ability of Polydopamine-Coated Gutta-Percha With Bioceramic Sealer: An In Vitro Study

Achieving a three-dimensional seal of the root canal system is essential for successful endodontic treatment. However, the hydrophobic nature of gutta-percha may compromise the interaction with the hydrophilic bioceramic sealers, leading to interfacial gaps and potential microleakage. Polydopamine (PDA) surface modification has recently emerged as a bioinspired strategy to enhance surface wettability and adhesion of biomaterials.

To evaluate the sealing ability, adaptability, and wetting ability at the sealer-gutta-percha interface of PDA-coated gutta-percha cones with bioceramic sealer using the single-cone obturation technique.

Sealing ability was assessed by measuring the apical dye penetration. Fourteen extracted mandibular premolars were instrumented using ProTaper Next rotary system, then randomly assigned into two groups (n = 7): uncoated or PDA-coated gutta-percha with bioceramic sealer. Interfacial adaptability between sealer and gutta-percha was examined using scanning electron microscopy (SEM). Wetting ability was evaluated by measuring the contact angle between the bioceramic sealer and the gutta-percha discs using 28 gutta-percha discs (n = 14) for both groups. Data were analyzed using one-way ANOVA and Student's t-test (α = 0.05).

In the sealing ability test, PDA-coated gutta-percha demonstrated significantly lower dye penetration (3.04 ± 0.59 mm) than the uncoated gutta-percha (4.3 ± 1.11 mm) (p < 0.05). SEM analysis demonstrated improved interfacial adaptability between the bioceramic sealer and PDA-coated gutta-percha, with no detectable gaps after 28 days in simulated body fluid (SBF), compared to uncoated gutta-percha, which showed interfacial gaps throughout the root at all time points. In addition, PDA-coated gutta-percha significantly reduced the contact angle (28.8° ± 9.4°) compared to the uncoated gutta-percha discs (77.4° ± 27.1°) (p < 0.05), indicating enhanced wettability.

PDA surface modification significantly improved the wettability, interfacial adaptation, and the sealing performance of the gutta-percha when used with a bioceramic sealer. Clinically, this bioinspired coating may contribute to the quality and durability of root canal obturation.