In vivo and in situ evaluation of innovative approaches in dentin hypersensitivity treatment

Abstract

Background: Dentin hypersensitivity (DH) causes transient sharp pain from exposed dentinal tubules, adversely affecting oral health and quality of life. This study compared the efficacy of two innovative treatments against Sodium Fluoride Varnish in reducing DH and occluding dentinal tubules over eight weeks.

Methods: This randomized, triple-blind, three-parallel-arm clinical and in situ study included a total of 63 participants (age range: 26-46 years), each randomly assigned to one of three treatment groups: PRG Barrier Coat, Embrace varnish, or Duraphat varnish. The clinical trial assessed pain intensity was assessed using Visual Analog Scale (VAS) after tactile, evaporative, and thermal stimuli at baseline, 3 min, 2 weeks, 4 weeks, and 8 weeks. The in-situ phase evaluated dentinal tubules occlusion pre- and post-treatment using scanning electron microscopy (SEM) at 2000× magnification. Statistical Analysis was conducted using Kruskal-Wallis and Friedman tests for intergroup and intragroup comparisons, respectively, and Spearman's correlation for pain reduction-tubule occlusion relationship (p < 0.05).

Results: PRG Barrier Coat achieved the highest efficacy with 94.9% pain reduction and 96.9% tubule occlusion. Embrace varnish showed moderate results with 64.3% pain reduction and 69.7% tubule occlusion, while Duraphat varnish provided limited performance with 45.4% pain reduction and 48.3% tubule occlusion. PRG Barrier Coat exhibited the most prolonged effects in reducing dentin hypersensitivity, aligning with its higher tubule occlusion. Embrace varnish demonstrated moderate performance, showing initial pain relief that was less sustained over time. Duraphat varnish provided the least reduction in pain and tubule occlusion, with effects that appeared transient.

Conclusions: This study demonstrated that PRG Barrier Coat and Embrace varnish effectively reduced pain intensity and promoted dentinal tubule occlusion, with PRG Barrier Coat showing the most sustained effects. These findings highlight the importance of dentinal tubule occlusion in DH management and suggest that treatment selection should consider both immediate pain relief and durability of therapeutic effects.

Trial registration: ClinicalTrials.gov (NCT04568473) on September 23, 2020.

Keywords: Dentin hypersensitivity; Dentinal tubules obliteration; Dentinal tubules occlusion; Duraphat; Embrace; Giomer; PRG barrier coat; Sodium fluoride; Xylitol-coated calcium phosphate.

Fig. 1

CONSORT flow diagram

Fig. 2

Schematic representation of the in-situ experimental protocol. The diagram illustrates sequential steps of teeth selection, dentin specimen preparation, sterilization, pretreatment, fabrication of customized fixed intraoral appliances, application of desensitizing agents, and subsequent SEM imaging with quantitative image analysis. Created in BioRender. Abd ELFattah, H. (2025) https://BioRender.com/a21a075

Fig. 3

SEM images of demineralized dentin following Stage I treatment. (A) SEM photomicrograph of demineralized dentin after Stage I, showing exposed dentinal tubules following tremoval of smear layer. (B) Analyzed SEM photomicrograph of demineralized dentin after Stage I, illustrating quantification of patent dentinal tubule surface area using image analysis software. Scale bar = 50 μm

Fig. 4

SEM images of dentinal tubules before and after treatment with PRG barrier coat. (A) SEM image of demineralized dentin after Stage I, showing exposed dentinal tubules following removal of smear layer. (B) Analyzed SEM image of demineralized dentin after Stage I, showing quantified patent dentinal tubule surface area using image analysis software. (C) SEM image of demineralized dentin after Stage II, treated with PRG Barrier Coat, showing dentinal tubule occlusion. (D) Analyzed SEM image of PRG-treated dentin after Stage II, illustrating tubule occlusion quantification. Scale bar = 50 μm

Fig. 5

SEM images of dentinal tubules before and after treatment with Embrace varnish. (A) SEM image of demineralized dentin after Stage I, showing exposed dentinal tubules following removal of smear layer. (B) Analyzed SEM image of demineralized dentin after Stage I, showing quantified patent dentinal tubule surface area using image analysis software. (C) SEM image of demineralized dentin after Stage II, treated with Embrace varnish, showing dentinal tubule occlusion. (D) Analyzed SEM image of Embrace-treated dentin after Stage II, illustrating tubule occlusion quantification. Scale bar = 50 μm

Fig. 6

SEM images of dentinal tubules before and after treatment with Duraphat varnish. (A) SEM image of demineralized dentin after Stage I, showing exposed dentinal tubules following tremoval of smear layer. (B) Analyzed SEM image of demineralized dentin after Stage I, showing quantified patent dentinal tubule surface area using image analysis software. (C) SEM image of demineralized dentin after Stage II, treated with Duraphat varnish, showing dentinal tubule occlusion. (D) Analyzed SEM image of Duraphat-treated dentin after Stage II, illustrating tubule occlusion quantification. Scale bar = 50 μm

Fig. 7

Scatter plot illustrating correlation between pain intensity reduction percentage and percentage of change in patent dentinal tubule surface area across all treatment groups (PRG Barrier Coat, Embrace varnish, and Duraphat varnish)