• Journal of the korean academy of Pediatric Dentistry
• /
• v.35 no.1
• /
• pp.57-64
• /
• 2008

It is well established that fluoride products play an important role in the prevention and remineralization of carious lesion. Fluoride varnish is a concentrated topical fluoride and varnishes adhere to tooth surface, permitting prolonged fluoride exposure and uptake. In this study, the artificial initial enamel caries was caused on the sound human enamel and divided 60 specimens into three groups. Group 1 and group 2 were treated with the topical application of fluoride varnish and stored in artificial saliva for 1 and 2 weeks. Group 3 was stored in artificial saliva for 2 weeks, which acted as control group. Changes in mineral contents were analysed with the confocal laser scanning microscope. The following results were obtained: 1. In group 1 and group 2, the total fluorescence of the lesion(TFL) was reduced in remineralized area compared to in demineralized area(p<0.05). 2. The total fluorescence of the lesion of remineralized area was more reduced in group 2 than in group 1(p<0.05). 3. The total fluorescence of the lesion was more reduced in group 2 than in control group(p<0.05). 4. Confocal laser scanning microscope can be used in quantitative analysis of remineralization by fluoride varnish.

• Journal of Technologic Dentistry
• /
• v.19 no.1
• /
• pp.175-184
• /
• 1997

The purpose of this study is to examine the effect of parents knowledge on oral health status toward their children. This study was carried out to investigate and analyze the congnitive degree of dental subjects and public who have an experience to be treated for their teeth on the dental knowledge, operative dentistry, and dental prothesis in the oral health care through the questionnaires. The results are as follows; 1. In questioning the fundamental knowledges, 47.6% of respondents in their thirties said that milk tooth of their children are number 20. Although schooling level of their parents is not rel evant to this survey, 21.9% who have only high-school diploma, said also "number 20". As a conclusion, most parents have a big concern in their children's teeth. 2. 44.0% parents answered, asked "who do decayed teeth sping up, and 26.4% said" It is why children eat sugary. Asked "What is efficient preventive measures decayed teeth", 26.5% said it is very relevant to be in the utilization of F-tooth-paste. 3. For children's good theeth, periodically brushing is the important. Most parents recognized brushing efficient. 4. In questioning the possession amount of decayed teeth, 45.8% have more than four. Usually those parents who have children filled their decayed teeth with artificial or installed with dental prosthesis. As a conclusion age is relevant in this study in P<0.05 level. 5. In asking for efficient starting-year of tooth brushing, 42.6% said that 2 or 3 year age is the most efficient, and especially 80.6% teath children to learn brushing themselves(P<0.05) 6. In surveying the way they obtained dental information, 38.9% were given from mass media, but 90% were once not delivered with the education of dental health. Because parents have been know narrow and deficient information of dental health mass media, experts in dental health have to deliver help their parents to be delivered with systematical dental information. The conclustion of this study can summarized that parent's role very important to their children's tooth health and the education program for systematical dental information should be delivered to their parents.

• The korean journal of orthodontics
• /
• v.30 no.3 s.80
• /
• pp.273-285
• /
• 2000

The aim of this investigation was to evaluate the differences of two canti-leyer springs by using a new simulation system. This was done using a Calorific machine that compared iron uprighting spring and root uprighting spring. The Calorific machine was designed to allow observation of the whole process of tooth moving, and is composed of three parts(a temperature regulating system, electro-thermodynamic teeth, and an artificial alveolar bone component). The experiment of both mechanics were repeated five times and measured two times. The intra-examiner agreement and inlet-examiner agreement were $96.54\%\;and\;95.73\%$ and these data were statistically tested by paired t-test. The obtained results were as follows. 1. Distal and buccal movement of the anchor teeth were observed greater in the root uprighting spring than the crown uprighting spring. 2. Crown uprighting spring showed distal movement of the crown of lower second molar for 3.29mm but root uprighting spring showed only 1.68mm. 3. Crown uprighting spring exhibited forward movement of mesial and distal root of the lower second molar for 3.91mm, 3.60mm but the root uprighting spring showed 6.76mm, 6.26mm.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.40 no.4
• /
• pp.247-252
• /
• 2013

Pit and fissure sealant prevents biofilm accumulation, plays a role in forming a barrier to acidic substance made by the bacteria. The Surface reaction-type pre-reacted glass ionomerI(S-PRG) filler was developed in 1999. S-PRG filler releases fluoride continuously and does not decompose under wet conditions. The aim of this study was to test the microleakage and anticariogenic effect to adjacent enamel of S-PRG filler-containing pit and fissure sealant. Sound premolars and molars were used in this study. A S-PRG filler-containing pit and fissure sealant, Beautisealant$^{(R)}$(Shofu, Japan) was used for this experiment, the composite resin sealant Concise$^{(R)}$(3M ESPE, USA) was used as control. For the microleakage test, all teeth surface were double coated with finger nail varnish, with the exception of a 1.0 mm window around the restoration margins. The teeth were immersed in 2% methylene blue solution for 24 hours and then rinsed in tap water. For the anticariogenic effect evaluation, all tooth were immersed in artificial carious solution for 9 days and rinsed with tap water. Each tooth was embedded in orthodontic acrylic rein and subsequently sectioned longitudinally in a bucco-lingual direction with a low-speed diamond saw. The cut sections were examined using a stereomicroscope. Differences in microleakage between the two groups were not different significantly. But the S-PRG filler-containing pit and fissure sealant showed higher anticariogenic effect than that of flowable resin sealant.

• Journal of dental hygiene science
• /
• v.17 no.6
• /
• pp.481-486
• /
• 2017

The study aimed to compare the whitening efficacy of a strip and gel containing 2.9% hydrogen peroxide, using a tooth whitening light activator. The whitening effect was compared through in vitro and in vivo studies. In the in vitro study, we used stained hydroxyapatite (HAP) specimens as artificial teeth. HAP specimens were made using HAP powder and polyvinyl alcohol solution, and stained by modified Stookey's method. A whitening gel and whitening strip were applied to the respective specimens for 20 minutes, with a light activator. The color changes were measured using a colorimeter. In the in vivo study, one group (test 1) used the gel with a light activator and the other group (test 2) used a strip with the same activator for 15 minutes a day, for four consecutive days. An organoleptic evaluation using a Vita shade guide and instrumental evaluation using a Shade eye-NCC (Shofu Co., Japan) were performed. The color change values (${\Delta}E^*$) in the in vitro study revealed the strip with the light activator to be more effective than the gel with the same activator (p<0.001). In the in vivo study, even though there was no significant difference between the groups with respect to the ${\Delta}E^*$, using either the Shade eye-NCC or the Vita shade guide, the change in yellowness (${\Delta}b^*$) was statistically significant (p=0.024). In conclusion, test 2 group that used 2.9% hydrogen peroxide strip with a light activator, showed a tendency towards increased whitening than test 1 group that used the gel with the same activator; however further studies are needed to validate the above finding.

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

• Restorative Dentistry and Endodontics
• /
• v.25 no.1
• /
• pp.1-16
• /
• 2000

It is difficult to treat the endodontic apical perforation successfully. In this study, we hypothesized that the application of PDGF-BB and IGF-I into periapical perforation site may accelerate periapical healing and lead to bone deposition. And the specificity of osteonectin in periapical healing was investigated. The experiments were performed on the upper and lower 51 premolar teeth of 4 beagle dogs. The pulp chamber of each tooth was opened and the dental plaque was inserted into the canal for developing the periapical lesion for 5 weeks. Then, the roots were artificially perforated at the apex with the number 4 profile of .06 taper. In each step, standard periapical radiographs were taken to compare the size of lesion each other. The radiographs were scanned and analyzed by image analysis system. The mean and standard deviation of periradicular radiolucency ratios were calculated in each group. ANOVA was used for comparison. 51 premolars were grouped into 3 groups; control group, calcium hydroxide-treated group and calcium hydroxide plus growth factors-treated group. In the control group, the apical perforations were not sealed and obturated with gutta-percha and ZOE sealer by lateral condensation technique. In the experimental groups, the apical perforation were sealed with calcium hydroxide and with/without $4{\mu}g$ of PDGF-BB & IGF-I in cellulose gel and obturated by lateral condensation technique. Fluorescent bone markers were used to measure new bone formation. Following 2, 4, 12 weeks after experiment the dogs were sacrificed and histologic sections were prepared. Each tooth block including periapical lesion was sectioned mesiodistally. One half of the sections were decalcified with 6% nitric acid and processed by standard paraffin embedding technique. The sections were stained by hematoxylin and eosin, and immunostained for osteonectin. Histomorphometrical measurement of neoformed bone was performed using a light microscope. And the other half of the sections were prepared by undecalcified preparation, and confocal laser scanning microscopic investigations were done.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.46 no.3
• /
• pp.293-300
• /
• 2019

As a common side effect of fixed orthodontic treatment, demineralization of the enamel adjacent to the bracket and band occurs in patients with poor oral hygiene. The purpose of this study was to investigate what is the most effective method to prevent demineralization around the fixed orthodontic appliance among various methods using fluoride. 80 extracted bovine incisors with a healthy surface were classified into four groups as experimental materials: (Group I) Control group, (Group II) V $varnish^{TM}$, (Group III) Tooth Mousse $Plus^{(R)}$, (Group IV) $Vanish^{TM}$ XT. After treatment for each group, mineral loss and Vickers surface microhardness were measured at 0, 30, 60 and 90 days after demineralization in artificial carious solution. Mineral loss was the lowest in group IV, followed by group II and group III, which showed a significant difference. The surface microhardness was the lowest in group IV, followed by group II and group III, which showed a significant difference. Through this study, group IV showed the best effect to prevent enamel demineralization around the bracket. Group III showed significant prevention of enamel demineralization compared with the control group, but the effect was less than that of the other groups.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.36 no.4
• /
• pp.272-281
• /
• 2020

Agenesis of permanent tooth in adolescent patients can be treated either by orthodontic treatment for space closure or by maintaining the space until implant restoration can be carried out in adult. However, gradual atrophy of alveolar bone width makes it difficult to restore the prosthesis in the future or may cause unaesthetic results. Therefore, maintaining of not only the missing space but also the alveolar bone width should be considered. This case is a treatment whereby a temporary replacement of missing 2 mandibular incisors in adolescent patient was carried out using 2 temporary anchorage devices (TADs). Two TADs were placed horizontally 2 - 3 mm below the top of alveolar ridge, and fixed with artificial teeth by stainless steel wires extended. During the 2 year follow-up, neither gingival inflammation nor loss of the TADs have occurred. In the radiographic evaluation, the growth of the adjacent alveolar bone was not inhibited, and the width of the alveolar bone was maintained.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.38 no.2
• /
• pp.146-154
• /
• 2011

An in vitro study on cariogenic potential of 8 over-the-counter syrups for children was performed. The experimental groups were 8 over-the-counter syrups. The positive control group was 10% sucrose solution, and the negative control group was artificial saliva. The pH of each group was determined. The buffering capacity was measured by the volume of 2 N NaOH adding to equalize the pH of 20 ml of experimental solution to pH 7. The consistency was measured by the time to pass Ostwald pipette for 2 ml of the experimental solution. The experimental solutions were inoculated with S. mutans and cultured in $37^{\circ}C$ anaerobic condition for 48 hours. To estimate acid production, pH of the experimental solutions were measured before and after the culture. The primary teeth specimens were soaked in the experimental solutions for 20 minutes three times a day. Except on those hours the specimens were stored in artificial saliva. After 5 days, the microhardness changes of the specimens were measured. These results show that most of syrup-form medicines for children tend to have cariogenic potential partially in endogenous pH, buffering capacity, consistency, acid production and erosive ability of enamel. For the oral health of children, the alternative sweeteners (ex. xylitol) may be substituted for the cariogenic sweeteners of syrups. Additionally, It may be helpful that the chewable tablet replace liquid or syrup in term of dose form.