Effects of Chlorhexidine-Encapsulated Mesoporous Silica Nanoparticles on the Anti-Biofilm and Mechanical Properties of Glass Ionomer Cement.

Huiyi Yan,Hongye Yang,Kang Li,Cui Huang,Jian Yu

doi:10.3390/molecules22071225

Abstract

One of the primary causes for the failure of glass ionomer cement (GIC) is secondary caries. To enhance the anti-microbial performance of GIC without affecting its mechanical properties, chlorhexidine (CHX) was encapsulated in expanded-pore mesoporous silica nanoparticles (pMSN) to synthesize CHX@pMSN. CHX@pMSN was added at three mass fractions (1%, 5%, and 10% (w/w)) to GIC powder as the experimental groups. Pure GIC was set as the control group. The mechanical and anti-biofilm properties of GIC from each group were tested. The results demonstrated that CHX was successfully encapsulated on/into pMSN, and the encapsulating efficiency of CHX was 44.62% in CHX@pMSN. The anti-biofilm ability was significantly enhanced in all experimental groups (p < 0.001) compared with that in the control group. CHX was continuously released, and anti-biofilm ability was maintained up to 30 days. In addition, the mechanical properties (compressive strength, surface hardness, elastic modulus, water sorption, and solubility) of 1% (w/w) group were maintained compared with those in the control group (p > 0.05). In conclusion, adding 1% (w/w) CHX@pMSN to GIC led to conspicuous anti-biofilm ability and had no adverse effect on the mechanical properties of this restorative material. This study proposes a new strategy for preventing secondary caries by using CHX@pMSN-modified GIC.

Highlights

Glass ionomer cement (GIC) was first introduced by Wilson and Kent [1] in 1970s, and since it has been widely used in esthetic dentistry and has attracted increasing research attention.glass ionomer cement (GIC) can bind directly to the tooth structure via interaction with the natural apatite without light curing or rotary instruments [2]; as such, GIC is convenient and popular in less-developed regions and for patients with dental phobia
Streptococcus mutans (S. mutans) and other cariogenic bacteria could invade the GIC-dentin interfaces via microleakage to induce the occurrence of secondary caries, which will eventually result in the failure and replacement of Molecules 2017, 22, 1225; doi:10.3390/molecules22071225
This study aims to (1) establish a CHX delivery system based on expanded-pore mesoporous silica (CHX@pore mesoporous silica nanoparticles (pMSN)); (2) develop a new strategy that endows GIC with anti-biofilm ability by appropriate addition of CHX@pMSN; and (3) evaluate the effects of CHX@pMSN on the mechanical properties of the modified GIC

Summary

Introduction

GIC can bind directly to the tooth structure via interaction with the natural apatite without light curing or rotary instruments [2]; as such, GIC is convenient and popular in less-developed regions and for patients with dental phobia. GIC continuously releases fluoride, which remineralizes dentin and enamel surrounding the restorative materials and suppresses bacterial activities [3]. GIC is preferred over other tooth-color materials especially when used for senile caries, childhood caries and atraumatic restorative treatment [4]. Dental caries is principally derived from cariogenic bacteria (especially Streptococcus mutans) which participate in biofilm formation and subsequent cariogenesis [5]. Streptococcus mutans (S. mutans) and other cariogenic bacteria could invade the GIC-dentin interfaces via microleakage to induce the occurrence of secondary caries, which will eventually result in the failure and replacement of Molecules 2017, 22, 1225; doi:10.3390/molecules22071225 www.mdpi.com/journal/molecules

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