Effect Of Four Remineralization Agents On Eroded Enamel And Wear Of Acid Eroded Enamel

Background Dental erosion is the loss of dental hard tissue througheither chemical etching and dissolution by acids of non-bacterial origin orchelation. Tooth wear is the progressive loss of dental hard tissue mainlycaused by mechanical friction effect. Erosive tooth wear is the dentalerosion and tooth wear occur simultaneously, compared with the dentalerosion and tooth wear occur isolation, erosive tooth wear can lead to moreserious dental damage.At present, the methods of prevention of erosive tooth wear generallyincludes a change in eating habits to reduce dietary acid erosion of teeth,avoiding contact with the acidic environment, the use of drugs to enhancethe ability of tooth to resist acid, and so on. In daily life, fluoride is themost widely used. Casein phosphopeptide-amorphous calciumphosphate(CPP-ACP) is the agent extracted from the milk contains nofluorine ions The main mechanism of CPP-ACP is to promote theremineralization of dental hard tissue and to inhibit demineralization.CPP-ACP in combination with fluoride ion generated casein phosphopeptide-amorphous calcium phosphate fluoride(CPP-ACPF).Tri-calcium phosphate fluoride(TCP+F) is rich in calcium, phosphorus andfluorine ions, can prevent tooth demineralization and help the enamelrestoration and remineralization.Many domestic and foreign studies have found that there were fewresearches about the effect of various remineralization agents on preventionand treatment of dental erosion and tooth wear. The study based on theresearch methods of domestic and foreign scholars, is aimed at comparingthe effect of four remineralization agents(CPP-ACP、CPP-ACPF、TCP+F、Duraphat fluoride varnish) on eroded enamel and acid eroded enamel wear,providing a clinical reference to prevent dental erosion and erosive toothwear for the children and adolescents.Objectives To compare the effect of CPP-ACP, CPP-ACPF, TCP+Fand Duraphat on surface microhardness and surface morphology of erosiveprimary and permanent teeth enamel. To compare the effect ofCPP-ACP，CPP-ACPF，TCP+F and Duraphat on surface microhardnessand surface morphology after toothbrushing wear of acid eroded enamel.Materials and Methods1. Comparison of the effect of fourremineralization agents on eroded enamel. Retained mandibular primarycentral incisors and impacted mandibular third molars were collected atclinic and50samples with hardness between280-330HV were selectedrespectively. The samples were processed into enamel slabs and then were randomly divided into five groups. The samples were first immersed intoCoca-Cola for5min,5times a day for5days. Distilled water, CPP–ACP,CPP-ACPF, TCP+F and Duraphat were respectively applied duringremineralization-erosion treatment for5days. The microhardness ofenamel surface before and after treatment was measured by microhardnesstester, the morphology changes of enamel surface was observed byscanning electron microscope（SEM）.2. Comparison of the effect of four remineralization agents on wear ofacid eroded enamel. Retained mandibular primary central incisors andimpacted mandibular third molars were collected at clinic and50sampleswith hardness between280-330HV were selected respectively. Thesamples were processed into enamel slabs and then were randomly dividedinto five groups. The samples were first immersed into Coca-Cola for5min,5times a day for5days. Then erosive enamel samples were subjectedto brushing wear with an electric toothbrush2N brushing load for3min,2times a day for5days. Distilled water, CPP–ACP, CPP-ACPF, TCP+F andDuraphat were respectively applied during brushing interval andwear-remineralization-erosion treatment was provided for5days.Microhardness of enamel surface before and after the treatment wasmeasured by microhardness tester and morphology changes of enamelsurface was observed by SEM.Results1. The microhardness in CPP–ACP group，CPP-ACPF group，TCP+F group, Duraphat group was obviously higher than that indistilled water group(P<0.05) and there was no significant differencebetween the former four groups. Lots of mineral deposit was observed withSEM in other four groups except in distilled water group.2. Microhardness in CPP–ACP group and CPP-ACPF group wasdecreased, having no significant difference compared with that of distilledwater group（P＞0.05）. Microhardness in TCP+F group and Duraphatgroup was increased，which is significantly higher than that of distilledwater group(P<0.05). A little of mineral deposit was observed with SEM inCPP–ACP group and CPP-ACPF group. Smooth enamel surface wasobserved with SEM in TCP+F group and Duraphat group.Conclusions1. CPP–ACP, CPP-ACPF, TCP+F and Duraphat caneffectively inhibit the erosive enamel demineralization continued.2. Duraphat and TCP+F can prevent the wear of constant acid erodedenamel.