Evaluation of the effectiveness of fluoridated and non-fluoridated desensitizing agents in dentinal tubule occlusion using scanning electron microscopy. An in-vitro study

Abstract

Background: Dentin hypersensitivity is primarily caused due to patent or exposed dentinal tubules.
Nonfluoridated‑desensitizing agents deposit hydroxycarbonate apatite (HCA), within the dentinal
tubules, thereby relieving hypersensitivity. Fluoride‑containing bioactive glass‑based agents form
fluorapatite which is less soluble when compared to hydroxyapatite and HCA.
Materials and Methods: In this in vitro study forty dentin specimens obtained from extracted
human premolars were divided randomly into four groups (n = 10): Group 1 – fluoridated
bioactive glass (FBaG); Group 2 – bioactive glass (BaG); Group 3 – arginine calcium carbonate;
Group 4 – saline. 37.5% phosphoric acid was used to ensure patent dentinal tubules. Test agents
from each group were applied using a rubber cup. Half the treated samples were then subjected
to 6% citric acid treatment. The degree of occlusion was evaluated using the scanning electron
microscope, and the microscopic images were scored before and after the citric acid challenge
by two blinded endodontists. Statistical analysis was performed using SPSS, one‑way ANOVA, and
post hoc Tukey test (P = 0.05).
Results: Group 1 demonstrated better tubule occlusion in comparison with Group 2 and a
statistically significant difference when compared to Group 3 (P = 0.001). Following acid challenge,
Group 2 showed significantly more occluded tubules when compared with Group 3 (P = 0.001)
and comparable difference with Group 1.
Conclusion: All desensitizing agents showed satisfactory dentinal tubule occlusion. While
fluoridated bioactive glass demonstrated better occlusion immediately after application, Bioactive
glass showed better resistance to acid treatment.