• Journal of the korean academy of Pediatric Dentistry
• /
• v.26 no.3
• /
• pp.538-553
• /
• 1999

The purpose of this study was to compare the shear bond strength and the anticariogenicity of glass ionomer cement with conventional bonding resin and fluoride releasing resin. After the shear bond strength test, scanning electron microscopic observation was performed for the evaluation of the fracture patterns in each group. Under the polarizing light microscope, artificially induced carious lesions were evaluated and the lesion depths of the samples were measured using image analyzing program(Image-Pro $PLUS^{TM}$, USA). 50 sound maxillary premolars were used for the bond strength test and another 30 for the anticariogenic test. Data collected were analyzed statistically using Oneway-ANOVA and Scheffe test. The results were as follows: 1. Glass ionomer groups(G-III, IV, V) generally showed the lower bond strength values than resin groups(G-I, II). 2. Among the two resin groups, G-I showed the higher bond strength than G-II without statistically significant difference between them(p>.05). 3. Within glass ionomer groups, statistical significance was found between G-III and G-V with the superior bond strength in G-V (p<.05). 4. Under the SEM, adhesive failure was the predominant fracture pattern in G-I and II, whereas cohesive failures were mainly observed in G-III. In G-IV and V, mixed type of pattern where the both fracture patterns coexisted within samples could be seen. 5. In evaluation of the depth of artificially developed carious lesion, glass ionomer group showed shallower depth than resin groups with statistical significance between G-III and G-I, II(p<.05). Among resin groups, fluoride releasing resin(G-II) showed the shallower depth than conventional resin(G-I)(p<.05).

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

• The korean journal of orthodontics
• /
• v.28 no.1 s.66
• /
• pp.51-59
• /
• 1998

The purpose of this study was to evaluate the effectiveness of gargling solution with 0.05% NaF and 10% Xylitol in orthodontic patients with fixed appliance. The sample consisted of 30 adolescent patients who were classified into an experimental group and a control group, 15 patients each. Experimental group was used experimental gargling solution and the control group was used with placebo solution. The change of S. mutans in saliva was observed by $Cariescreen^R$ SM kit at pre and post 2, 4, 6, 8 weeks. The results were as follows 1. There were significant reduction in the number of S. mutans in saliva between pre and post 2 weeks(p<0.01), 4 weeks(p<0.05), 6 weeks(p<0.001), and 8 weeks(p<0.001) in experimental group. And significant reduction also were observed in the number of S. mutans in saliva between post 2 weeks, 6 weeks(p<0.05), and 8 weeks(p<0.05), but no significant reduction were showed in control group. 2. There were significant correlation in the number of S. mutans between each measurement time(pre and post 2, 4, 6, 8 weeks) in control group. 3. There were no correlation between pre and post 2 weeks, but significant correlation were observed between 2, 4, 6, 8 weeks in experimental group.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.39 no.3
• /
• pp.257-266
• /
• 2012

The objective of this in vitro study was to monitor the amount of remineralization of decalcified enamel according to the number of fluoride varnish application using quantitative light-induced fluorescence-D and polarizing microscope. Artificial white lesion induced on the sound 72 teeth, $CavityShield^{TM}$ (Group I), $FluroDose^{TM}$ (Group II) and $Flor-Opal^{(R)}$ Varnish (Group III) were applied 1, 2 or 3 times every two weeks. The following results was obtained: 1. In group I, II and III, ${\Delta}L$ were increased. From regression analysis of ${\Delta}L$ by the number of application, the equation was y = 3.878x + 90.612 in group I, y = 3.133x + 37.168 in group II, and y = 3.509x + 82.322 in group III(p < 0.05). 2. In group I, II and III, ${\Delta}D$ were decreased. From regression analysis of ${\Delta}D$ by the number of application, the equation was y = -2.336x + 107.235 in group I, y = -2.158x + 101.620 in group II, and y = -1.940x + 94.806 in group III(p < 0.05). 3. The Pearson correlation value between the ${\Delta}L$ and ${\Delta}D$ was -0.673 in group I, -0.574 in group II, and -0.431 in group III(p < 0.05).

• Journal of the korean academy of Pediatric Dentistry
• /
• v.35 no.4
• /
• pp.684-691
• /
• 2008

Many operations have been carried out using the fluoride ion to prevent and reverse dental caries. It certainly encourages remineralization and also prevents dental caries. However, the remineralization developed by these means is superficial only leaving lower levels of demineralized lesion with a degree of porosity and incomplete mineralization. We must consider its toxic effects when it is ingested for overdose. The CPP-ACP paste is able to remineralize the incipient lesion and has no harmful effects when it is ingested, because it was made form casein which is from the protein of milk. The purpose of this article is to compare the remineralization effects between APF gel and the CPP-ACP paste. we applicated the APF gel and CPP-ACP paste on the artificial enamel carious lesion. After 14 days, we measured the surface microhardness and observed the remineralized lesion under polarized light microscope. The results were as follows : 1. The surface microhardness of group III was the highest, followed by group II, and I(p<0.05). 2. The surface microhardness of group III was significantly higher than those of group I, and II(p<0.05). 3. We could observe thin and irregular remineralization layer of group II, and regular and moderate remineralization layer of group III under polirized light microscope.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.45 no.2
• /
• pp.137-143
• /
• 2018

The aim of this study is to compare the differences of the demineralization resistance of resin infiltration and 1.23% acidulated phosphate fluoride in bovine teeth with artificial caries. We applied 1.23% Acidulated phosphate fluoride (APF) gel and $Icon^{(R)}$ caries infiltrant on the artificial bovine enamel carious lesion and then demineralized all samples. The depth of demineralization was measured by using Confocal Laser Scanning Microscope (CLSM) and observed the roughness and irregularity of the enamel was observed by Scanning Electron Microscope (SEM). In this experiment with demineralization resistance on smooth artificial carious lesion, less depth of demineralization, roughness, and irregularity of enamel was observed in APF gel and $Icon^{(R)}$ group than in the control group. There was no significant difference between the depth of demineralization of 1.23% APF gel and $Icon^{(R)}$ caries infiltrant group. However, resin infiltration is beneficial as less roughness and irregularity was observed on the enamel surface than when 1.23% APF gel is applied.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.38 no.4
• /
• pp.317-326
• /
• 2011

QLF-D system composed with DSLR(digital single-lens reflex) camera, and the images of natural enamel caries and artificial caries was developed from 2 days to 14 days captured by QLF-D system. The correlation between lesion depth of the polarized microscope and luminosity ratio of QLF-D image was analyzed and the results were summarized as follows: 1. The Pearson correlation value between the lesion depth of polarized microscope images and luminosity ratio of QLF-D images was 0.969(p<0.01). 2. From Regression analysis of lesion depth from polarized image by demineralized period, the equation was y = 8.67x - 1.16(p<0.05). 3. From Regression analysis of luminosity ratio from QLF-D image by demineralized period, the equation was y = 3.53x + 6.42(p<0.05). From the results, QLF-D system can detect the enamel caries at the very early stage and can monitor the progression of demineralization and remineralization. For the convenient use of QLF-D system in the laboratory, the image analysing software was needed to analyze of interest site of enamel caries lesion.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.4
• /
• pp.705-713
• /
• 2004

The objectives of this study were to evaluate the fluoride release and the change of surface roughness of fluoride releasing restorative materials after toothbrush-dentifrice abrasion. Seven commercially available fluoride releasing restorative materials (Fuji II LC Improved: FL, Compoglass F: CG, Dyract AP: DR, F2000: FT, Ariston: AT, Tetric: TR, and Gradia: GD) were selected as experimental materials. The results obtained were summarized as follows: 1. The AT, FL, and CF groups produce an initially large burst of fluoride release and comparatively low but continuous release of fluoride. But other groups produce no initial burst of fluoride and levels of release remain relatively constant. 2. The rate of fluoride release remains steady state after 40 days. The results of Tukey's test (P<.05), the fluoride release showed the order of decreasing rank as follows: AT > FL > compomers > TC and GD. 3. The surface roughness indicated that the highest value was observed in the FT group and the lowest value was observed in the CF group. The surface roughness of Tukey's test showed the significant differences between groups of FT, AT and FL and groups of CF, DR, GD and TC (P<0.05).

• The korean journal of orthodontics
• /
• v.29 no.5 s.76
• /
• pp.589-597
• /
• 1999

The purpose of this study was to evaluate the effects of fluoride releasing orthodontic sealants, light-cured (Group L1&L2) and self-cured (Group S1&S2) $FluoroBond^{\circledR}$, on enamel microhardness under artificial carious solution in vitro.112 extracted human premolar teeth were collected for experiments and divided into seven groups. A Tukon microhardness tester equipped with a Knoop diamond indenter was employed to determine microhardness. Tukon 23 program converted the number of microhardness into KHN (Knoop hardness number). The results were as follows: 1. The microhardness of enamel depth of all groups were the least at the depth of $50{\mu}m$ and that of all groups except L2 group, the greatest at the depth of $200{\mu}m$, were the greatest at the depth of $300{\mu}m$. And as the enamel depth of all groups except L2 and S2 group increased, the microhardness value also increased. 2. There was a little preventive effect in enamel decalcification both light-and self-cured orthodontic sealant groups, but had no statistical significance between the groups(p>0.05). 3. Light-cured orthodontic sealant groups had a progressive inhibiting effect in enamel decalcification at the depth of $100{\mu}m,150{\mu}m,\;and\;200{\mu}m$ (p<0.05). 4. Self-cured orthodontic sealant groups had a progressive inhibiting effect in enamel decalcification at the depth of $150{\mu}m$ (p<0.05). 5. There was no difference of the anti-enamel demineralization effect between light- and self-cured orthodontic sealant groups (p>0.05).

• Restorative Dentistry and Endodontics
• /
• v.36 no.4
• /
• pp.290-299
• /
• 2011

Objectives: The usage of fluoride varnish for a moderate to low caries-risk group has not been well validated. This study aimed to evaluate the preventive and therapeutic efficacies of fluoride varnish on the initiated root caries. Materials and Methods: Ten premolars were sectioned into quarters, further divided into two windows, one of which was painted with Fluor Protector (1,000 ppm fluoride, Ivoclar Vivadent). An initial lesion with a well-preserved surface layer was produced by pH cycling. Scanned line analysis using energy dispersive spectrometry determined the weight percentages of Ca and P in the demineralized layer. Scanning Electron microscopy and confocal laser scanning microscopy (CLSM) evaluated the varnish-applied root surfaces. Results: The mean lesion depth (SD) was 12.3 (2.6) ${\mu}m$ (single cycling) and 19.6 (3.8) ${\mu}m$ (double cycling). Double cycling extended the lesion depth, but induced no more mineral loss than single cycling (p < 0.05). The mean weight percentages of Ca and P between groups with and without varnish were not significantly different (p < 0.05). A CLSM showed varnish remained within 15 ${\mu}m$ of the surface layer. Conclusions: When a mild acid challenge initiated root tissue demineralization, the application of low-concentration fluoride varnish did not influence the lesion depth or the mineral composition of the subsurface lesion.