Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 22 0 2026 01 07 Occlusion of Dentinal Tubules by Nanohydroxyapatite and Zinc Carbonate Hydroxyapatite-Based Toothpastes as Desensitizing Agents: An in Vitro Study 4954 4954 Shubhankar Mehrotra Department of Periodontology, Manipal College of Dental Sciences, Manipal, Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India Rupali Agnihotri Department of Periodontology, Manipal College of Dental Sciences, Manipal, Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India 2023 09 12 2024 09 02 Objectives: Dentin hypersensitivity (DH), characterized by a short, sharp, and intense pain response to a stimulus, is the most commonly encountered patient complaint. Various in-office and at-home methods including the recently introduced nano-hydroxyapatite (n-HA) and zinc carbonate-hydroxyapatite (Zn-CHA)-based products reduce the DH discomfort. This study compared the effectiveness of commercially available n-HA and Zn-CHA toothpastes for occlusion of dentinal tubules for management of DH. Materials and Methods: In this in vitro study, 40 tooth samples were randomly assigned to 4 groups (n=10): negative control): brushing without toothpaste,Aclaim n-HA toothpaste,Biorepair Zn-CHA toothpaste, andShyNM calcium sodium phosphosilicate (CSPS) toothpaste. After demineralization with 17% ethylenediaminetetraacetic acid, the mounted specimens were brushed with an electric pressure-sensitive toothbrush and the respective toothpaste. Occlusion of dentinal tubules was subsequently evaluated under a scanning electron microscope (SEM). Elemental composition of the occluding plug was analyzed by energy-dispersive X-ray spectroscopy (EDX). Results: The test n-HA and Zn-CHAand the positive control (CSPS) groups revealed significantly higher tubular occlusion compared to the negative control group (p= 0.001). The highest tubular occlusion was achieved in n-HA and Zn-CHA groups (80%); while negative control showed no occlusion (0%). Elemental analysis of dentinal plug showed significant differences in carbon, oxygen, calcium, and phosphorus levels among the groups (p<0.05). Conclusion: The tubular occlusion capacity of Zn-CHA and n-HA were similar to CSPS-based toothpaste, and CHA in Zn-CHA enabled the formation of stable dentinal plugs. https://fid.tums.ac.ir/index.php/fid/article/view/4954 https://fid.tums.ac.ir/index.php/fid/article/download/4954/2197 https://fid.tums.ac.ir/index.php/fid/article/download/4954/2198