Calcium phosphates as fillers for methacrylate-based sealer.

OBJECTIVES

The aim of this study was to evaluate the mineral deposition, push-out bond strength, radiopacity, the degree of conversion, film thickness, flow, calcium ion release, and pH of experimental endodontic sealers containing hydroxyapatite (HAp), aflfa-ticalcium phosphate (α-TCP), or octacalcium phosphate (OCP) particles.

MATERIALS AND METHODS

Fifty single straight root human premolars were instrumented and divided into five groups (n = 10). Experimental endodontic sealers were formulated by 70 wt% urethane dimethacrylate (UDMA), 15 wt% of glycerol-1,3-dimethacrylate (GDMA), 15 wt% of ethoxylated bisphenol A glycol dimethacrylate (BISEMA), camphorquinone (CQ), N,N-dihydroxyethyl-para-toluidine (DHEPT), and benzoyl-peroxide. 10 wt% of each HAp, α-TCP, or OCP were added to the resin and its properties were assessed.

RESULTS

After 7 days, the degree of conversion ranged from 44.69% (G) to 50.74% (G) and no statistical difference were observed (p < 0.05). G showed the highest push-out bond strength 4.91 (± 2.38) MPa at 28 days of analysis (p < 0.05). Film thickness and pH were not statistically different (p > 0.05). Statically lower values of flow were found for G, G, and G (p < 0.05). Calcium deposition values were higher for G at 28 days.

CONCLUSIONS

Bond strength, degree of conversion, and film thickness of endodontic sealers with phosphates showed similar results compared with AHplus, but displayed higher amounts of Ca release.

CLINICAL RELEVANCE

Phosphate fillers improve the performance of endodontic sealers after 28 days of simulated body fluid.