Pulpal Response of Deep Cavities to Silver Diamine Fluoride Application in Wistar Rat Molars

This study aimed to evaluate the dental pulp response to different 38% silver diamine fluoride (SDF) products in Wistar rats with deep cavities.

Sixty-four maxillary first molars from Wistar rats were randomly assigned to eight groups (n = 8 per group) for 7-28 days treatments: Group 1- a locally produced 38% SDF (T-SDF), Group 2-Saforide (Toyo Seiyaku Kasei Co. Ltd., Japan), Group 3-Topamine (Dentalife Australia Pty. Ltd., Thailand), and Group 4-deionised water (DI) as control. After a deep cavity preparation, treatments were applied. Rats were euthanized at days 7 and 28 post-treatment, and molars were subjected to histopathological examination to evaluate inflammation, soft tissue organisation, reactionary dentine formation and silver penetration depth. Data were analysed using the Kruskal-Wallis; penetration depth was analysed using one-way ANOVA (p < 0.05).

At day 7, all groups showed no to mild inflammation beneath the axial wall, with no significant differences in inflammation scores (p > 0.05). Normal odontoblastic organisation was observed in the T-SDF and Saforide groups. Partial loss of soft tissue organisation occurred in 28.57% of the Topamine group and 16.66% of the DI group, though central pulp remained normal. Mean soft tissue organisation scores were 1.29 ± 0.488 for Topamine and 1.17 ± 0.408 for DI (p = 0.203). Reactionary dentine formation was noted across most teeth, with no significant differences among groups (p = 0.548). By day 28, no significant differences in inflammation or soft tissue organisation were observed (p > 0.05). Reactionary dentine formation ranged from none to over four times the predentine thickness, with no significant group differences (p = 0.932). The remaining dentine thickness of prepared cavities ranged from 71.70-594.76 μm. Silver precipitation was observed in all SDF-treated specimens, absent in controls. Silver penetration into dentinal tubules toward the pulp showed no statistically significant differences among groups at both days 7 and 28 (p = 0.741 and 0.607, respectively).

When applied in deep cavities, SDF products elicited a dental pulp response comparable to that of the control, indicating their biocompatibility and safety for use in deep dentine carious lesions.