• Journal of Korean society of Dental Hygiene
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• v.1 no.1
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• pp.125-132
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• 2001

This study was carried out to investigate the effect of multi or single application of fluoride plus 0.05% NaF solution on the remineralization of dental caries lesion. The microhardness changes of enamel surface were measured after application of fluoride and precipitation of 0.05% NaF solution on 6 groups of cow's tooth on which the artificial carious lesions were formed first. Test groups were calssified into two step application with NaF, $SnF_2$ and APF under different application time conditions plus 0.05% NaF solution(group I, II, III, IV) and single application with APF plus 0.05% NaF solution (group V) and control(0.05% NaF solution only, group IV). The obtained results were as follows. 1. Regarding microhardness change of enamel surface. microhardness increments in group I(NaF for 1 minute+APF for 3 minutes+0.05% NaF solution for 1 minute), II($SnF_2$ 1 min+APF 3 min+NaF sol.), III($SnF_2$ 2 min+APF 2 min+NaF sol.), IV(NaF 2 min+APF 2 min+NaF sol.) and V(APF 4 min+NaF sol.) were significantly greater than group VI.(P<0.05) 2. Microhardness changes of shorter application time of $SnF_2$ (group II) were significantly greater than group III. (P<0.05) 3. Microhardness changes were variable with kinds of fluoride, application sequence and application time of fluoride. but had no relation with the number of fluoride application.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.498-508
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• 2002

The purpose of this study was to compare the amount of fluoride release and remineralizing effect of compomer with those of glass ionomer cement and composite resin. Composite resin($Z-100^{(R)}$) was used for negative control group(Group I), glass ionomer(Fuji II $LC^{(R)}$) for positive control group(Group IV), compomer(Dyract $AP^{(R)}$ and $F-2000^{(R)}$) for experimental group(Group II and Group III). The results obtained can be summarized as follows : 1. Glass ionomer showed the higher amount of fluoride release than compomer groups. Composite resin showed no fluoride release during test period. 2. Significant evidence of remineralization could be noticed in samples of all groups. The highest degree of remineralization was observed in glass ionomer group followed by compomer group. The least evidence of remineralization was observed in composite resin group. 3. Microhardness values of carious site was lower than control site, but Microhardness values of caries site at form away from filling materials in group II, III, IV was significantly higher than the other area. Based on the above results, compomer could be considered as one of the very attractive restorative materials in the field of pediatric dentistry.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.207-220
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• 2006

The newly developed equipments for the early detection of carious lesion are LFD (laser fluorescence device), Ultrasonic diagnostic system, CLSM(confocal laser scanning microscopy), QLF(quantitative light-induced fluorescence) and DIFOTI (digital imaging fiber-optic trans-illumination) system. In this study, DIFOTI system and LFD were used for the detection of early enamel caries. Twenty five primary teeth extracted from twenty one children at around the dentitional exchanging period were selected as samples. The results obtained from DIFOTI imaging and LFD measurement were compared with those of CLSM and comprehensive evaluations were made for the diagnostic capacity of each device. In vitro test, 40 sample teeth with their buccal & lingual surface formed by a window of $2{\times}3mm$ in diameter were immersed in artificial demineralizing solution for the period of 4, 8, 12 and 16 days. The results obtained from the experimental groups (DIFOTI, LFD) were compared to control group (CLSM) and we have reached to the following conclusions. 1. The sensitivity and specificity of DIFOTI system operated in oral environment was 88.2% and 76.9% respectively. 2. The sensitivity and specificity of LFD measured in oral environment was 76.5% and 69.2% respectively. 3, Regression analysis on the light transparent rate of DIFOTI showed its decrease according to the length of primary enamel decalcification performed in vitro(r=-0.96, p<0.05). 4. No statistically significant difference between LFT measurement and the length of in vitro decalcification was found in regression analysis (p>0.05). 5. The correlation coefficient of DIFOTI image transparent rate and the lesion depth of CLMS was -0.6988 (p<0.05), whereas no statistically significant difference was found for LFD measurement.

• Restorative Dentistry and Endodontics
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• v.32 no.6
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• pp.498-513
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• 2007

Since it was reported that incipient enamel caries can be recovered, previous studies have quantitatively evaluated that enamel artificial caries have been, remineralized with fluoride showing simultaneously the increase of width of surface layer and the decrease of width of the body of legion. There is, however, little report which showed that remineralization could occur without fluoride. In addition, the observations on the change of hydroxyapatite crystals also have been scarcely seen. In this study, enamel caries in intact premolars or molars was induced by using lactic acidulated buffering solutions over 2 days. Then decalcified specimens were remineralized by seven groups of solutions using different degree of saturation(0.212, 0.239, 0.301, 0.355) and different pH(5.0, 5.5, 6.0) over 10 days. A qualitative comparison to changes of hydroxyapatite crystals after fracturing teeth was made under SEM(scanning electron microscopy) and AFM(atomic force microscopy). The results were as follows: 1. The size of hydroxyapatite crystals in demineralized area was smaller than the normal ones. While the space among crystals was expanded, it was observed that crystals are arranged irregularly. 2. In remineralized enamel area, the enlarged crystals with various shape were observed when the crystals were fused and new small crystals in intercrystalline spaces were deposited. 3. Group 3 and 4 with higher degree of saturation at same pH showed the formation of large clusters by aggregation of small crystals from the surface layer to the lesion body than group 1 and 2 with relatively low degree of saturation at same pH did. Especially group 4 showed complete remineralization to the body of lesions. Group 5 and 6 with lower pH at similar degree of saturation showed remineralization to the body of lesions while group 7 didn't show it. Unlike in Group 3 and 4, Group 5 and 6 showed that each particle was densely distributed with clear appearance rather than crystals form clusters together.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.467-475
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• 2021

The purpose of this study was to compare the effect of sodium fluoride(NaF) varnish and potassium iodide(KI) on remineralization efficacy of silver diamine fluoride(SDF) by measuring microhardness and evaluating surface morphology by scanning electron microscope(SEM). Artificial caries lesions were induced on extracted primary molars and vickers microhardness was measured. Specimens were randomly separated into 4 groups for treatment. The specimens in group I were treated with SDF, group II with NaF varnish after SDF, group III with KI after SDF and group IV with distilled water. After 8 days of pH cycling, vickers microhardness was measured and difference before and after treatment was calculated. For SEM, 2 samples were evaluated respectively after enamel polishing, lesion formation and after pH cycling. Group III showed highest increase in microhardness. Group I showed higher increase in microhardness than Group II but without statistical difference. Group IV showed lowest increase in microhardness value among 4 groups. On SEM image, group I, II and III showed smoother and less irregular surface compared to group IV. Amorphous crystal pellicles were observed in group III. In conclusion, SDF, SDF and NaF, SDF and KI groups showed smoother surface and increase in microhardness suggesting the possibility that remineralization effect might take place in oral conditions. In addition, in limited conditions of this study, applying NaF varnish after SDF did not increase the remineralization efficacy of SDF while KI significantly increased the remineralization efficacy of SDF. However, additional study considering various conditions that might affect demineralization and remineralization in clinical situations need to be conducted.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.38-45
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• 2009

The aim of this study was to examine efficacy of the commercially available 10% CPP-ACP cream (Tooth mousse, GC Co., Japan) and/or 0.05% NaF solution on the remineralization of artifical caries-like lesion in the bovine teeth enamel. Sixty bovine teeth were embedded in orthodontic resin and flattened. The enamel surface in 3 mm diameter was exposed with nail varnish. Specimens were stored in demineralizing solution and divided 5 groups; Group 1 (No treatment), 2 (0.05% NaF solution 1 min), 3 (Tooth mousse 3 min), 4 (After 0.05% NaF solution, Tooth mousse treatment), and 5 (After Tooth mousse treatment, soaking in 0.05% NaF solution during 1 min). After treatment by groups, all specimens was stored in artificial saliva for 30 min. After the process described as above was performed during 10 days without pH cycling, surface hardness (Vickers Hardness Number, VHN) was tested and analyzed by paired t-test and one-way ANOVA test with SPSS 14.0. In intragroup comparison between surface hardness of pre and post-treatment, group 3, 4, 5 showed statistically significant increase (P < 0.05). In intergroup comparison among surface hardness increase of all groups, difference of group 5 between pre and post-treatment ($15.80{\pm}12.21$) was the highest, and followed by group 4 ($14.27{\pm}11.73$), 3 ($4.05{\pm}5.18$), 2 ($1.15{\pm}6.83$), 1 ($0.78{\pm}6.21$). Tooth mousse can be a good alternative agent for the fluoride, and the combination use with fluoride might have the additional anticariogenic effect.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.1
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• pp.209-224
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• 1998

The purpose of this study was to compare the amount of calcium fluoride deposited on the enamel and dentin surface and to obtain information on the morphological change and crystallographic details of mineral deposition after 12,000ppm APF application in vitro. The bovine enamel and dentin blocks were randomly assigned to eight groups according to artificial caries lesion formation and difference of fluoride application time. The fluoride concentration and morphological characteristics on the treated enamel and dentin surface were investigated by using fluoride quantitative analysis and SEM. The powdered enamel and dentin of the intact bovine incisors were prepared for the X-ray diffraction analysis. The following results were obtained. 1. The amounts of KOH-soluble fluoride on the carious enamel and dentin surface after 24h APF application were higher than after only 5min APF application(p<0.05), but in the case of the sound enamel and dentin surface were similar after 5min and 24h application (P>0.05). The fluoride content was highly increased in the carious dentin as compared with sound dentin after APF application(P<0.05). 2. The carious enamel surface after APF application, the demineralized enamel surface were recovered a more dense enamel surface and precipitation of crystal was observed a distintive surface layer of spherical globules of about 1 m diameter. In the case of the fluorided carious dentin surface, precipitation of calcium fluoride-like material was deposited both inside the dentinal tubules as well as in the intertubular regions. 3. The crystallographic structure of powdered enamel and dentin after 24h APF application had large crystallities of apatite and CaF2 diffraction peaks in the enamel as compared with dentin. The diffraction data collected from the 27.50-29.50(2) angular range of the powdered enamel, the (105) apatite, (225) apatite and (111) CaF2 peaks of the enamel crystallities were detected after 24h APF application.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.4
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• pp.382-391
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• 2019

This study was aimed to assess the new trial for minimal cavity preparation in composite restoration combined with resin infiltration, focusing at application sequence. 32 human primary molars with early carious lesions around small cavity were selected and randomly divided into two groups, according to the sequence of cavity preparation (P), composite filling (F) and resin infiltration (I) as IPF and PFI group. Each group was assessed about amount of tooth reduction, features of resin infiltration, and marginal leakage around restoration. Amount of tooth reduction evaluated using micro-CT was decreased compared with the original lesion size in both groups. Features of resin infiltration were verified under confocal laser scanning microscopy. In both groups, infiltrant resin was found on all around the composite and maintained in spite of extent of decalcification even after artificial caries induction. Marginal micro leakage assessed with silver nitrate immersion and micro-CT was found more frequently in PFI group. The technique combining resin infiltration and composite restoration might ensure better adhesion prognosis as applied by the sequence of resin infiltration, cavity preparation, and composite filling. This new trial was thought meaningful in minimizing the cavity size and contributing to minimal invasive dentistry.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.474-480
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• 2004

The purpose of this in vitro study was to compare the remineralizing effects of three glass ionomer cements (high filled glass ionomer cement, compomer, resin modified glass ionomer cement) with resin composite (control group) on incipient interproximal caries, and to assess long-term change of remineralization effect, in each material, evaluated by microtomography. Proximal restoration was simulated with tooth specimen and Glass Ionomer Cements. And each of these groups was placed into a closed container with artificial saliva at $37^{\circ}C$ and pH 7.0 for a time period of thirty days with constant circulation. At the end of thirty and sixty days, tomographic images were taken from these specimens with micro CT scanner. Materials used in this study were as follows. Group 1: Fuji IX GP (GC Corp., Tokyo, Japan) Group 2: Vitremer (3M ESPE, St. Paul, Minn., USA) Group 3: F2000 (3M ESPE, St. Paul, Minn., USA) Group 4: Z250 (3M ESPE, St. Paul, Minn., USA) Using density-measuring program, the micro-density of carious lesions on the specimens were measured. The mean density changes of each group were compared to the other groups to evaluate the effect of remineralization. The results were as follows: 1. The lesion density of all groups increased. 2. The mean density increase of Group 1, 2, 3 were higher than that of Group 4 every month(p<0.05). 3. There were significant differences of density increase among glass ionomer group(Group 1, 2, 3).