Effectiveness of a nanoemulsion-containing Nigella sativa nanoparticles encapsulated in propolis nanomicelles on dentin tubule occlusion: An scanning electron microscopy study.

BACKGROUND

Dentin hypersensitivity (DH) is a prevalent clinical condition, occurring when exposed dentin reacts to various thermal, chemical, or mechanical stimuli. Although different interventions such as fluoride varnish, adhesives, and natural bioactive compounds have been tested, there is still a demand for more effective and durable solutions.This study aimed to evaluate the ability of a nanoemulsion containing Nigella sativa nanoparticles encapsulated in propolis nanomicelles to occlude dentinal tubules and to compare its performance with fluoride varnish under the simulated acidic and mechanical challenges.

MATERIALS AND

METHODS

In this in vitro study, hydroethanolic extract of Nigella sativa was encapsulated in propolis-based micelles to prepare the nanoemulsion. Thirty-six extracted human third molars were sectioned at the mid-crown and randomly assigned to four groups (n = 9): (1) normal saline, (2) nanoemulsion (15-min immersion), (3) nanoemulsion (30-min immersion), and (4) 5% fluoride varnish. Each group was further divided into three subgroups: control (no challenge), acid challenge, and simulated toothbrushing. Scanning electron microscopy at × 4000 magnification was used to quantify the percentage of occluded dentinal tubules. Data were analyzed with the two-way analysis of variance and least significant difference post hoc tests at a significance level of P ≤ 0.05.

RESULTS

Material type (P = 0.018), challenge regimen (P < 0.001), and their interaction (P < 0.001) significantly influenced occlusion percentage. The highest occlusion was observed with nanoemulsion (30-min immersion) in the acid challenge subgroup (46.78%), followed by nanoemulsion (15-min immersion) after toothbrushing (41.85%), and fluoride varnish in the acid challenge subgroup (37.19%). Acidic and brushing challenges significantly reduced occlusion in all groups (P < 0.001).

CONCLUSION

Nanoemulsion containing Nigella sativa nanoparticles within propolis nanomicelles demonstrated superior dentinal tubule occlusion compared to fluoride varnish, with notable resistance to acid and brushing challenges. Given their natural origin, anti-inflammatory, and remineralizing properties, such nanoformulations may offer an effective and biocompatible alternative for managing DH. Clinical studies are recommended to validate these findings in vivo.