Experiment About Three Kind Of Resins In Initial Enamel Caries

Objective: The aim of this study is to compare the ICON, Z350 and fissure sealant in aspect of penetration depths, surface roughness and micro hardness when they are applied on artificial enamel lesions. The consequence of the study is intended to provide guidance for the elect of material used to treat initial enamel lesions.Methods: 1 Pretreatment of samples 1.1 Chioce of samples: fresh extracted bovine incisor teeth were collected and removed tiny deposits of calculus and stains. Then put them in normal saline after ultrasonic concussion. No caries, demineralization, pigment, cracks and obvious shape differences was the criteria for select. 1.2 Primary manage of samples: each bovine tooth was cut into lumps with the shape of 7mm×7mm×2mm and polished(600-grit). Using acid-resistant nail to create a small window about 5mm×5mm in each sample. 1.3 Building of artificial enamel caries: put the samples in demineralizing solution(50mmol/L acetic acid, 3mmol/L Ca Cl2, 3mmol/L KH2PO4, p H4.5) for 4 days to make artificial enamel lesions. 1.4 Signing of the caries lesions: samples were etched with 15% hydrochloric acid gel for 2 min and then put into stain for 12 h to sign the lesions with red fluorescench. 2 Grouping of samplesThe samples were dividing in 4 groups(n=15): Aapplying ICON-Dry and ICON-Infiltrant; B) applying Z350(3M,American); C) applying the fissure sealant(3M,American); D)control. After treating with resins, put the samples in 30% H2O2 for 12 h to clean the redundant stain and dry them. 3.1 Measure of the roughness: all the samples were tested using surface profilometer to get the roughness. 3.2 Measure of the hardness: all the samples were tested by the Vickers Hardness test(50g)to get the hardness. 3.4 Percentage of the penetration: samples were incised into a sheet. The thickness was less than 1mm. Polishing the sheets with abrasive paper until the samples were lucenc. Put the samples into another stain to sign the structures not be infiltrated with green fluorescench. Lesions(LD) and penetration(PD) depths were analyzed by using confocal microscopy(CLSM). Calculating the penetration percentage(PP). 4 Analyzed the data with SPSS(ANOVA and LSD test).Results:1 surface profilometer(Ra)The numeric of Ra(μm) for four groups were: A(0.45±0.04); B(0.68±0.08); C(0.31±0.05); D(1.40±0.04).The results showed that there were significant differences between every two groups(P<0.05). The numeric of group D was the highest while the numeric of group C was the lowest. The numeric of group B was higher than group A.2 micro-Vickers Hardness(VHN)The numeric of micro-Vickers Hardness for four groups were: A(302.30±24.82); B(236.80±17.15); C(209.10±15.80; D(48.5±2.28).The results showed that there were significant differences between every two groups(P<0.05). The numeric of group A was the highest, followed by the group B. The numeric of group C was higher than that of group D.3 penetration percentage(PP)The penetration percentage for four groups were: A(0.92±0.03); B(0.82±0.04); C(0.77±0.04); D(0.00±0.00).The results showed that the penetration percentage for samples of group A was the highest and have significant differences between the other three groups(P<0.05). Group B was slightly higher than group C but have no 3 Measure of datasignificant difference with group C(P>0.05). The PP for group D were lowest and is significant difference with the other three groups(P<0.05).Conclusion:1 Smoothness of the initial enamel caries treated with fissure sealant is the best.2 Infiltrant can improve the micro-Vickers Hardness prominently in the initial enamel caries.3 Infiltrant is the most capable of infiltrating the initial enmal caries lesions.