Mineralising and antibacterial effects of modified calcium phosphate treatment on human root cementum

Haijing Gu,Ziming Zhao,Junqi Ling,Jin-Long Gao,Limin Liu,Xiaoyan Zhou

doi:10.1186/s12903-016-0246-4

Abstract

BackgroundAging population will lead to the increase of incidence of root caries globally. The clinical management of root caries is challenging due to the difficulty in moisture isolation. The root caries is caused by the release of organic acids from cariogenic bacteria which results in the dissolution of cementum and dentin of the root. The purpose of this study is to study the efficacy of modified saturated calcium phosphate solution (CaP) supplement with zinc (Zn2+) and/or fluoride (F-) in providing root cementum surfaces less susceptible to acid dissolution and bacterial colonization.MethodsHuman root cementum sections from extracted premolars were treated with three modified calcium phosphate solutions (M/A-CaPs) respectively: (A) CaP-F/Zn, supplemented with F- and Zn2+; (B) CaP-F, supplemented with F- only; (C) CaP-Zn, supplemented with Zn2+ only. The surface characteristics of treated cementum sections were investigated using scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR). Following the acid attack and Streptococcus mutans challenge, M/A-CaPs treated cementum surfaces were analysed using inductive coupled plasma (ICP) and SEM respectively.ResultsCompared with the control group, M/A-CaPs treated cementum presented significant improvements in resistance to acid dissolution and bacterial colonization. Among M/A-CaPs, the CaP-F/Zn treated cementum surfaces released the lowest amount of Ca2+ ions (2.11 ± 0.51 ppm) upon acid challenge (n = 3, p < 0.01) and also presented the most significant inhibiting effect against the colonization of S. mutans (n = 180, p < 0.05).ConclusionsSaturated calcium phosphate solution CaP supplemented with both F- and Zn2+ could be applied as an effective coating material providing acid resistance and antibacterial property on cementum surfaces. The modified calcium phosphate-based solution could be a new treatment strategy to prevent the development of root caries and arrest the further progression of root caries.

Highlights

Aging population will lead to the increase of incidence of root caries globally
Cementum surfaces treated with calcium phosphate solution (CaP)-F/Zn (Fig. 1a) and CaP-F (Fig. 1b) were shown to be coated by compact and homogenous fine crystal precipitates
A Determination of anti-bacterial property Streptococcus mutans strain ATCC 25175 was used to evaluate the effect of the coating on bacterial colonization on cementum surface

Summary

Introduction

Aging population will lead to the increase of incidence of root caries globally. The clinical management of root caries is challenging due to the difficulty in moisture isolation. Due to traumatic tooth brushing, periodontal diseases [7, 8], bleaching, and orthodontic movement of teeth [9], gingival recessions were found in more than 60 % of the younger population (50 years). It causes the early exposure of cementum on the root surface which increases susceptibility to root caries [10, 11]

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