Role of Desensitizing Dentifrices on Dentinal Wear and Tubule Occlusion.

Objectives: To assess the effects of various active ingredients in desensitizing dentifrices on erosion-abrasion resistance and dentinal tubule occlusion.
Methods: Sixty dentin samples from human third molars were randomly assigned to six groups (n=10): 1. Negative control (NC) using distilled water, 2. Conventional fluoride toothpaste (C), 3. Toothpaste containing sodium and calcium phosphosilicate (CSP), 4. Toothpaste with arginine, calcium carbonate, and zinc phosphate (ACZP), 5. Toothpaste containing calcium fluoride phosphosilicate (CFPS), and 6. Toothpaste with arginine and calcium carbonate (AC). The erosion-abrasion protocol consisted of exposing the samples to 1% citric acid for 5 minutes, followed by immersion in artificial saliva for 60 minutes, repeated 4 times/day over 5 days, with brushing twice daily. Surface loss (SL) was assessed through optical profilometry at baseline, and after the first, third, and fifth days. The number of open dentinal tubules per area was also analyzed via environmental scanning electron microscopy, both before treatment and after cycling, in three specimens per group.
Results: Dentin slabs from sound human third molars were assigned to six groups (n=10 per group): C- (negative control, distilled water), C+ (fluoride dentifrice without desensitizing agents), CSP (sodium and calcium phosphosilicate), ACZP (arginine, calcium carbonate, and zinc phosphate), CFSP (fluoro-calcium phosphosilicate), and AC (arginine and calcium carbonate). A 5-day erosion-abrasion cycling was conducted, consisting of citric acid exposure (1%, 2 min) followed by artificial saliva (60 min) six times per day, with twice-daily toothbrushing (45 strokes). Surface loss (SL) was measured using an optical profilometer at baseline, and after the first, third, and fifth days. Dentinal tubule occlusion was evaluated via environmental scanning electron microscopy (n=3) at baseline and after the final cycle. Statistical significance was set at α = 0.05.
Conclusions: The tested dentifrices had similar effects on both dentin loss and tubule occlusion. Toothbrushing with these dentifrices did not result in more erosive wear than distilled water. The dentifrice containing fluoro-calcium phosphosilicate was the only one that caused less surface loss than the negative control after five days of erosion-abrasion cycling.