Reduction in dentin permeability using a slurry containing dicalcium phosphate and calcium hydroxide

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Nanotechnology in Dentistry

Background:

• Dentin hypersensitivity is a common clinical issue.
• Obturating dentin tubules is a key strategy for managing dentin hypersensitivity.
• Micron-sized particles offer potential for effective tubule blockage.

Purpose of the Study:

• To evaluate the efficacy of a micron-sized calcium phosphate slurry in reducing hydraulic conductance (Lp) of etched dentin in vitro.
• To assess the long-term effects of the treatment on dentin tubule patency.

Main Methods:

• Etched dentin discs were treated with a slurry containing dicalcium phosphate anhydrous, calcium hydroxide, sodium fluoride, and carboxymethyl cellulose.
• Hydraulic conductance (Lp) was measured at baseline and after 2, 4, and 7 days of incubation in a saliva-like solution (SLS).
• Scanning electron microscopy (SEM), X-ray diffraction (XRD), and chemical analyses were used to characterize the treated dentin and the formed product.

Main Results:

• The treatment significantly reduced Lp of etched dentin discs over the 7-day incubation period.
• Mean relative Lp decreased from 100% at baseline to 33% after 7 days.
• SEM revealed partial obturation of dentin tubules, and XRD/chemical analysis identified fluoride-containing hydroxyapatite as the major product.

Conclusions:

• The tested micron-sized calcium phosphate slurry effectively obturates dentin tubules.
• This treatment demonstrates significant potential for reducing dentin hypersensitivity by decreasing hydraulic conductance.
• The formation of fluoride-containing hydroxyapatite contributes to the observed tubule occlusion and potential therapeutic benefits.