The Effect of Nano-Hydroxyapatite Particles on Dentinal Tubule Occlusion and Adjunctive Use of Ozonated Olive Oil (Scanning Electron Microscopic Study)

Background: Dentin hypersensitivity (DH) is a prevalent dental condition marked by sudden pain resulting from the exposure of dentinal tubules. Two main strategies are proposed for addressing this clinical dental issue: occlusion of dentinal tubules and inhibition of nerve activity. Desensitizing agents have gained popularity as products for tubule occlusion. Ozone degrades the smear layer, facilitating the penetration of desensitizing agents into the dentinal tubules.Objective: Assessment of the durability and impact of nano-hydroxyapatite (nHA) particles on dentinal tubule occlusion in vitro, using ozonated olive oil as an adjuvant.Design: After collecting and cleaning 24 freshly extracted human premolar teeth, dentin discs measuring approximately 2.0 mm thick were cut above the cementoenamel junction perpendicular to the tooth’s long axis. For 20 seconds, the dentin discs were etched with 37% orthophosphoric acid to eliminate the smear layer, open the tubules, and create a DH model. Specimens were randomized into three groups (n=8/group): Group 1 (Control): no treatment; Group 2 (nHA): treated with nHA; and Group 3 (nHA + ozone): received nHA combined with ozonated olive oil. Tubule blockage was confirmed through SEM, followed by administering a citric acid challenge. Results: Group 3 exhibited more densely occluded tubules as well as more compact nHA deposits compared to Group 2, which demonstrated a lesser degree of occlusion post-acid challenge.Conclusion: Adjunctive ozonated oil and nHA application synergistically enhanced occlusive efficacy by increasing tubule permeability, facilitating deeper and more compact particle penetration. Consequently, it may serve as a more promising treatment in DH management.