Anti-Caries Effects of Dental Adhesives Containing Quaternary Ammonium Methacrylates with Different Chain Lengths.

Qi Han,Xuedong Zhou,Michael Weir,Hockin Xu,Haohao Wang,Yu Chen,Xian Peng,Suping Wang,Lei Cheng,Keke Zhang,Biao Ren,Mingyun Li,Yang Ge,Bolei Li,Mingye Feng

doi:10.3390/ma10060643

Abstract

The objectives of this study were to investigate the effects of dental adhesives containing quaternary ammonium methacrylates (QAMs) with different alkyl chain lengths (CL) on ecological caries prevention in vitro. Five QAMs were synthesized with a CL = 3, 6, 9, 12, and 16 and incorporated into adhesives. Micro-tensile bond strength and surface charge density were used to measure the physical properties of the adhesives. The proportion change in three-species biofilms consisting of Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii was tested using the TaqMan real-time polymerase chain reaction. Lactic acid assay, MTT [3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, exopolysaccharide staining, live/dead staining, scanning electron microscopy (SEM), and transverse microradiography (TMR) were performed to study the anti-biofilm and anti-demineralization effects of the dental adhesives. The results showed that incorporating QAMs with different alkyl chain lengths into the adhesives had no obvious effect on the dentin bond strength. The adhesives containing QAMs with a longer alkyl chain developed healthier biofilms. The surface charge density, anti-biofilm, and anti-demineralization effects of the adhesives increased with a CL of the QAMs from 3 to 12, but decreased slightly with a CL from 12 to 16. In conclusion, adhesives containing QAMs with a tailored chain length are promising for preventing secondary caries in an “ecological way”.

Highlights

Dental caries has emerged as a major public health problem across the world, affecting about60–90% of schoolchildren and the vast majority of adults [1,2]
The cause of dental caries is the accumulation of dental biofilms, characterized by the accumulation of aciduric and acidophilic bacteria, which leads to the accumulation of acid within the biofilms and to demineralization on enamel [9,10]
Compared compared with the saliva-derived microcosmmicrocosm biofilm model with a complex amicrobial complexcommunity, microbial community, the controlled multi-species biofilm model with a defined the controlled multi-species biofilm model with a defined community has community has an advantage in achieving a high degree of reproducibility between experimental runs [36]

Summary

Introduction

Dental caries has emerged as a major public health problem across the world, affecting about. 60–90% of schoolchildren and the vast majority of adults [1,2]. Resin composites are popular to fill tooth cavities by adhesive bonding [3,4,5]. Great progress has been made in developing. Materials 2017, 10, 643 composites and adhesives, half of all restorations failed within 10 years, and replacing them cost. Secondary caries is the primary reason for this failure [8]. Multiple strategies and anti-caries agents were developed to enhance the anti-biofilm capability of dental materials [11,12,13]

Objectives

Methods

Results

Conclusion