KJC Korea
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To investigate knowledge and attitude of parents about early childhood caries and dental caries prevention, a questionnaire survey was conducted on 247 parents of children who had oral screening experience among 3 to 5 years old children in 3 kindergartens in Jeonju city. A total of 220 completed questionnaires were selected for final analysis. The overall perception of the parents about oral health of the children was 82.3 points (10.7 / 13) in terms of 100 points. There were statistically significant correlations between maternal age (p = 0.027), maternal education level (p = 0.002), household monthly income (p = 0.000) and maternal oral health knowledge level. The main source of oral health information was ‘dentist and dental hygienist’(83.6%) followed by ’Web search’(22.3%). Compared with the previous studies, the level of knowledge of parents about oral health of the children was improved. However, in order to raise awareness of the parents about the poorly assessed items in this study, it is necessary to increase the participation rate by advertising the national dental screening program for infants and children and make efforts to improve the quality of oral health education in screening.

This study was to measure and compare the amount of fluoride, microhardness and solubility of high viscosity glass ionomer and resin-reinforced glass ionomer during 84 days. Fuji IX GP EXTRA, Fuji IX GP, Fuji II LC and Filtek™ Z350XT stored in deionized water for 84 days to measure fluoride release, microhardness and solubility. As a result of measurement of fluoride release, all the glass ionomers showed the highest amount of fluoride release on day 1 and gradually decreased. Fuji IX GP EXTRA showed the highest amount of fluoride release and cumulative release. And Fuji IX GP and Fuji II LC showed no significant difference. Microhardness measurements showed that all experimental groups decreased 1 day after exposure to water. After 84 days, microhardness showed no significant difference between Fuji IX GP EXTRA and Fuji IX GP, and Fuji II LC was the lowest. In the solubility measurement, Fuji IX GP EXTRA, Fuji IX GP, and Fuji II LC increased rapidly to 21 days. After 21 days, there was no significant difference in the three groups. As a result, short term fluoride release affects solubility and microhardness, but long term fluoride release has no correlation. Through this study, the amount of fluoride, microhardness, and solubility of various glass ionomers were evaluated, and these properties could be applied clinically.

The aim of this study was to evaluate the proximal caries detecting ability and identify the optimal cut-off values of two types of laser fluorescence (LF) devices; classic type (DD) and pen type (DDpen). The number of proximal surfaces participated in this study were 164 surfaces in primary dentition and 438 surfaces in permanent dentition. Each tooth surface was sequentially assessed by two types of LF devices, and bitewing radiograph. The radiographs were classified into 3 groups in primary dentition (pR0, pR1, pR2), and 4 groups in permanent dentition (PR0, PR1, PR2, PR3) according to the depth of caries, and used as gold standard. In primary dentition, the area under the curve (AUC) values of DD were 0.851 and 0.890, and those of DDpen were 0.883 and 0.917, respectively in enamel caries and dentin caries. In permanent dentition, the AUC values of DD were 0.762 and 0.886, and those of DDpen were 0.828 and 0.958, respectively in enamel caries and dentin caries. When detecting proximal caries in posterior teeth with LF devices, DDpen is more useful than DD in both primary and permanent dentition. However, in primary dentition, DD can also be useful to detect proximal caries.

The purpose of this study was to compare the shear bond strengths of 3-in-1 flowable composite to the enamel and dentin of primary teeth to previous adhesive systems. 110 primary incisors were prepared and divided into two groups: Dentin group included 5 groups: 1) Scotch bond Multi-purpose plus(DSM), 2) Single-bond 2(DSB), 3) Clearfil SE bond(DSE), 4) All bond universal(DAB), 5) Constic(DC), and Enamel group included 6 groups: 1) Scotch bond Multipurpose plus(ESM), 2) Single bond 2(ESB), 3) Clearfil SE bond(ESE), 4) All bond universal(EAB), 5) Constic(EC), 6) Constic with additional etching(ECE). A cylinder of composite was bonded to the prepared surface, and the shear bond strength was measured. In the dentin groups, group DC had significantly lower shear bond strength than group DSE. No significant difference was found between group DC, group DSM, group DSB and group DAB. In the enamel groups, there was no significant difference between group EC, group ESE, and group EAB. This material showed lowest shear bond strength among all tested materials in both enamel and dentin groups, showing insignificant difference with some adhesive systems. Therefore, 3-in-1 flowable composite can be used for primary teeth restoration but further studies are needed.

The aim of this study was to measure the shear bond strength (SBS) of different adhesive systems to calcium silicatebased materials (Biodentine and RetroMTA). Eighty cylindrical acrylic blocks, with a hole (5.0 mm diameter, 2.0 mm height) in each, were prepared. The holes were filled with Biodentine (BD) and RetroMTA (RMTA), and the specimens were divided into 2 groups. Each group was classified into 4 subgroups: ClearfilTM SE (CSE) ; AQ bond (AQ) ; All bond universal Self-etch (ABU-SE) ; and All bond universal Total-etch (ABU-TE). After the application of different adhesive systems, composite resin (Z350) was applied over BD and RMTA. The SBS was measured using a universal testing machine, and the data were compared using the Kruskal-Wallis test and the Mann-Whitney test. The highest and lowest values of SBS were observed for BD-ABU-SE and RMTA-AQ, respectively. No significant differences were found in the SBS between ABU-TE and ABU-SE and between ABU-TE and CSE to BD and RMTA. According to the data, BD showed a higher SBS than did RMTA when BD and RMTA are compared in the same adhesive agents. Further, among all groups, composite resin with ABU-SE showed better bond strength to BD and RMTA.

The purpose of this study was to evaluate the effect of the intracanal medicaments on the push-out bond strength of the calcium silicate-based materials. Forty extracted single-root human mandibular premolars were sectioned below cementoenamel junction. Standardized root canal dimension was obtained with a parallel post drill. The specimens were randomly divided into a control group (no medicament), and experimental groups received medicaments with either CH (calcium hydroxide), DAP (double antibiotic paste; a mixture of ciprofloxacin and metronidazole), or TAP (triple antibiotic paste; a mixture of minocycline, ciprofloxacin and metronidazole). Following removal of medicaments with irrigation, roots were cut into sections with 1-mm-thickness. Thereafter, calcium silicate-based materials are applied to the specimens : (i) ProRoot MTA® and (ii) Biodentine®. A pushout bond strength was measured and each specimen was examined to evaluate failure mode. Intracanal medication using CH significantly increased the bond strength to the root dentin. But there are no significant differences on the bond strength of ProRoot MTA® or Biodentine® among TAP, DAP and control groups. The dislodgement resistance of Biodentine® from root dentin was significantly higher than that of ProRoot MTA® regardless of the type of intracanal medicaments.

The purpose of this study was to investigate the distribution of eruption disturbance and to analyze its causes, treatment methods, and duration of orthodontic traction, based on 703 patients with eruption disturbance who were treated in the pediatric dental clinic of Seoul National University Dental Hospital between July 2011 and June 2016. Eruption disturbance in pediatric patients was most prevalent in the maxillary canine, followed by the maxillary central incisor and maxillary first molar. Eruption disorder of the maxillary canine was more common in females (p < 0.001), whereas the maxillary central incisor (p = 0.009), maxillary first molar (p < 0.001) and mandibular first molar (p = 0.028) were more common in males than females. The most common causes of eruption disturbance were abnormality of the eruption pathway and the presence of obstacles in the pathway. Orthodontic traction was the most prevalent treatment choice for eruption disorder, mostly done for the maxillary central incisors. The duration of orthodontic traction was shorter with younger age (p < 0.001) and lower crown position (p < 0.001). It is important for pediatric patients to detect eruption disorders early through regular checkup, and it is necessary to initiate treatment at an appropriate time with an accurate diagnosis and treatment plan.

The aim of this study was to investigate difference of child’s dental fear and agreement between parent/child dyads according to parental rearing style. The subjects were 801 children aged 8 and 11-year old and their parents in Jeonju city. The parents were asked to answer a questionnaire which included four parental rearing style and the Children’s Fear Survey Schedule - Dental Subscale(CFSS-DS) at home. Also, the CFSS-DS was completed by 8 and 11 years old children in a classroom. Authoritative, permissive, authoritarian and neglectful parenting styles were 53.4%, 45.8%, 0.2% and 0.6% respectively. Authoritative and permissive parents reported 5.7 and 7.5 points higher than dental fear scores reported by their children. At 8 years old, children of authoritative parents were significantly 3.9 points higher than them of permissive parents(p = 0.002). Also, parent/child dyads showed moderate agreement assessing dental fear at aged 8. Parenting styles are related to children’s dental fear, and especially 8-year-old girls in authoritative parenting styles have the highest dental fear. However, as age increased, the impact of parental styles on children’s dental fear decreased.

Tooth agenesis is a common human dental anomaly and the agenesis of mandibular second premolars has been proven to be the most frequently observed. The aim of this study is to investigate tooth agenesis and delayed tooth development in patients with agenesis of mandibular second premolars. This study reviewed 9 to 15 year-old patients with agenesis of mandibular second premolars who visited the department of pediatric dentistry of Yonsei University Dental Hospital and took panoramic radiographs from January 2014 to December 2016. On panoramic radiographs, agenesis of teeth was observed and developmental delay of teeth was evaluated by the Nolla method. Among 125 patients with agenesis of mandibular second premolars, 58 patients (46.4%) showed agenesis of other teeth and 38 patients (30.4%) showed delayed tooth development. In this study, patients with agenesis of mandibular second premolars were more likely to have tooth agenesis or delayed eruption of other teeth.

This study was conducted to investigate the characteristics of subculture times in the early, middle, and late passages by measuring the time under subculture until it was judged that the supernumerary tooth-derived pulp stem cells (sDPSCS) were no longer proliferating. Three supernumerary teeth from two healthy six-years old boys were extracted and stem cells were obtained from the pulp tissue. This was called SNT1 (supernumerary tooth 1), SNT2, and the supernumerary tooth from another child was named SNT3. SNT1 and 2 were subcultured at the same time and SNT3 was subcultured a little faster. The mean time of complete subculture was 3.6 ± 1.1 days. Total passages were cultured up to 23.3 ± 0.6 and took 83 days. These were divided into three groups based on the passage. The increase rate of time taken in subculture between group I and group II was 11.9%, but the rate between group II and group III was 28.6%, which was 2.4 times increased. The time taken between passages during long-term subculture up to 22 passages shows a regressive pattern y = 0.1169x + 2.25 and y = 0.1169x + 2.0. In conclusion, the passage time of SPSCs increased in late passages, and it shows a similar pattern.

The purpose of this study was to improve efficacy of oral health education in children and adolescents based on the experience and perception of oral health education in young adults who graduated from high school within 10 years. Questionnaires were given to 412 people, and among them, 388 completed survey forms were selected. The questionnaire included categories which examined one’s experience and perception of oral health education, oral health knowledge, dental history, and oral health behavior. The results showed that the respondents perceived elementary school as the most effective period of oral health education. Oral examination with direct explanation was the most preferred method of oral health education, but web search was the main source of oral health information. And knowledge of fluoride and sealant about caries preventive effect was still lacking. Considering these results, oral examination with direct explanation and web search would be useful to improve efficacy of oral health education in children and adolescents.

Tidal volume by sevoflurane in small amounts is stable due to the increase in the breathing rate. But alveolus ventilation decreases due to sevoflurane as the degree of sedation increases; this ultimately causes PaCO2 to rise. The occurrence of suppression of breath increases the risk of severe hypoxia and hypercapnia in deeply sedated patients with disabilities. Sevoflurane inhalation anesthesia has a number of risks and may have unexpected problems with hemodynamic changes depending on the underlying state of the body. This study was conducted to examine the stability of internal acid-base system caused by respiratory depression occurring when patients with disabilities are induced by sevoflurane. Anesthetic induction was carried out by placing a mask on top of the patient’s face and through voluntary breathing with 4 vol% of sevoflurane, 4 L/min of nitrous oxide, and 4 L/min of oxygen. After the patient’s loss of consciousness and muscle relaxation, IV line was inserted by an expert and intravenous blood gas was analyzed by extracting blood from vein. In a deeply sedated state, the average amount of pH of the entire patients was measured as 7.36 ± 0.06. The average amount of PvCO2 of the entire patients was measured as 48.8 ± 8.50 mmHg. The average amount of HCO3 - of the entire patients was measured as 27.2 ± 3.0 mmol/L. In conclusion, in dental treatment of patients with disabilities, the internal acid base response to inhalation sedation using sevoflurane is relatively stable.

Congenital absence of the primary canines is very rare. Congenital absence of primary teeth often causes their successors to not develop at all or affects the eruption of their successors. The purpose of this paper was to report the cases of 2 children with early eruption of the maxillary permanent canines at ages 4 and 6 years, respectively, following congenital absence of their maxillary primary canines, which are not common in earlier studies. Although tooth eruption and shedding exhibit some physiological variation, certain clinical cases are extreme. Premature eruption of the maxillary permanent canines may cause complications in terms of the space available for the eruption of adjacent teeth. Additionally, early eruption of permanent teeth increases the need for more careful oral hygiene. Therefore, the pediatric dentist must be alert to such rare cases.

In dental trauma, reattachment of the original tooth fragment improves the reproduction of original tooth shape, texture, color, and radiolucency; thus, it provides good aesthetics. A 9-year-old boy was referred due to complicated crown-root fracture of the maxillary right central incisor. Although it had poor prognosis due to severe coronal damage and subcrestal fracture, reattachment of the tooth fragment was chosen due to the patient’s age. One-visit apexification with mineral trioxide aggregate (MTA) was performed, followed by osteotomy and reattachment of the tooth fragment with post placement. Regular observation revealed no clinical signs or symptoms and no radiologic complications.