Novel Crown Cement Containing Antibacterial Monomer and Calcium Phosphate Nanoparticles.

Rashed Alsahafi,Abdulrahman A Balhaddad,Thomas W Oates,Mary Anne S Melo,Michael D Weir,Heba Mitwalli,Maria Salem Ibrahim,Hockin H.K Xu

doi:10.3390/nano10102001

Abstract

Oral biofilm accumulation at the tooth–restoration interface often leads to recurrent dental caries and restoration failure. The objectives of this study were to: (1) develop a novel bioactive crown cement containing dimethylaminohexadecyl methacrylate (DMAHDM) and nano-sized amorphous calcium phosphate (NACP), and (2) investigate the mechanical properties, anti-biofilm activity, and calcium (Ca2+) and phosphate (PO43−) ion release of the crown cement for the first time. The cement matrix consisted of pyromellitic glycerol dimethacrylate and ethoxylated bisphenol-A dimethacrylate monomers and was denoted PEHB resin matrix. The following cements were tested: (1) RelyX luting cement (commercial control); (2) 55% PEHB + 45% glass fillers (experimental control); (3) 55% PEHB + 20% glass + 25% NACP + 0% DMAHDM; (4) 52% PEHB + 20% glass + 25% NACP + 3% DMAHDM; (5) 51% PEHB + 20% glass + 25% NACP + 4% DMAHDM; (6) 50% PEHB + 20% glass + 25% NACP + 5% DMAHDM. Mechanical properties and ion release were measured. Streptococcus mutans (S. mutans) biofilms were grown on cements, and colony-forming units (CFUs) and other biofilm properties were measured. The novel bioactive cement demonstrated strong antibacterial properties and high levels of Ca2+ and PO43− ion release to remineralize tooth lesions. Adding NACP and DMAHDM into the cement did not adversely affect the mechanical properties and dentin bonding strength. In conclusion, the novel NACP + DMAHDM crown cement has excellent potential for restoration cementation to inhibit caries by suppressing oral biofilm growth and increasing remineralization via Ca2+ and PO43− ions. The NACP + DMAHDM composition may have wide applicability to other biomaterials to promote hard-tissue formation and combat bacterial infection.

Highlights

Secondary caries at the margins of fixed dental restorations have been reported as the most common cause of failure in such treatment [1]
The present study showed that the nano-sized amorphous calcium phosphate (NACP) + dimethylaminohexadecyl methacrylate (DMAHDM) crown resin cement achieved flexural strength comparable to the experimental control and higher than the commercial control cement
This study developed a novel bioactive dental crown cement containing antibacterial monomer and calcium phosphate nanoparticles

Summary

Introduction

Secondary caries at the margins of fixed dental restorations have been reported as the most common cause of failure in such treatment [1]. The tooth-restoration interface is a complex environment with a dynamic equilibrium in substances and minerals present in saliva and hard tooth tissues. When the equilibrium shifts to an acidic environment, the tooth structure will start to demineralize in a way similar to primary caries [3]. Characteristics that increase the accumulation of food debris or limit its cleaning can be considered as potential risk factors for secondary caries, which is likely why secondary caries mainly occur at the tooth-restoration interface [4]

Objectives

Methods

Results

Discussion

Conclusion