ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the occluding effects of three new calcium desensitizers on dentinal tubules in vitro.</p><p><b>METHODS</b>Twenty-five dentin specimens of 1.00 mm thick from freshly extracted third molars were divided into five groups randomly. After treatment with 6% citric acid, group A was treated with distilled water, and group B-E were treated with NovaMin, Pro-Argin, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), and 75% NaF glycerin for 2 min respectively. Then the teeth were vertically cleaved into two sections. The surfaces and cross sections were observed by the scanning electron microscope (SEM) and energy dispersive X-ray (EDX), which were analyzed by the Image-Pro Plus software.</p><p><b>RESULTS</b>The percentage of dentin tubules sealed were (81.6 ± 6.1)%, (71.5 ± 6.3)%, (43.2 ± 2.6)%, (39.9 ± 4.1)% for groups B, C, D and E respectively, and the occluding depth were (30.33 ± 2.26), (24.55 ± 2.58), (16.10 ± 4.65) and (8.90 ± 1.51) µm respectively. The differences between these groups were statistically significant (P < 0.01) except for group B and C (P > 0.05). However, there was no significant difference between all the groups for the Ca/P ratios (P = 0.342).</p><p><b>CONCLUSIONS</b>NovaMin may have better immediate occluding effects than other desensitizers and could deposit a dentin-like mineral.</p>