This study was conducted to investigate the fluoride release of fluoride-containing restorative materials in fluoride recharging according to the concentration of fluoride toothpaste used in Korea.
Samples of glass ionomer cement, resin-modified glass ionomer cement, alkasite restorative material, and composite resin were prepared and fluoride release was measured on days 1, 3, 7, 14, 21, 28. Thereafter, fluoride-free, 500 ppm, and 1450 ppm fluoride toothpaste was applied to each restorative materials, and the fluoride release was measured on days 1, 3, 7.
Glass ionomer cement showed the highest cumulative fluoride release until the 7th day of measurement, and from the 14th day onwards, the resin-modified glass ionomer cement showed the highest cumulative fluoride release, but there was no significant difference.
When restorative material groups were recharged with 500 ppm of fluoride toothpaste, the fluoride release was significantly higher only for the alkasite restorative material compared to the fluoride-free toothpaste group (p < 0.017). When restorative material groups were recharged with 1450 ppm of fluoride toothpaste, the fluoride release was significantly higher in all restorative groups compared to the fluoride-free toothpaste group (p < 0.017).

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.
Apexification ; Child ; Esthetics ; Humans ; Incisor ; Male ; Miners ; Osteotomy ; Pemetrexed ; Prognosis ; Reproduction ; Tooth

This study aimed to determine whether the curing times of Xtra Power and High Power modes of high-power light emitting diode (LED) curing light are sufficient for polymerization of resin sealants. The specimens were prepared and their microhardness values were measured and compared with those of specimens polymerized under conventional LED curing light.The filled sealant polymerized for 8 seconds in the High Power mode and for 3 seconds in the Xtra Power mode showed significantly lower microhardness than the control specimen (p = 0.000). The unfilled sealant polymerized for 8, 12 seconds in the High Power mode and for 6 seconds in the Xtra Power mode showed significantly lower microhardness than the control specimen (p = 0.000).The results of this study suggest that the short curing time with the Xtra Power and High Power modes of highpower LED curing light are not sufficient for adequate polymerization of sealants under specific conditions, taking into account the curing times and the type of sealant.
Polymerization ; Polymers

The purpose of this study was to investigate the changes of the position of the mental foramen according to age by using panorama of children with mixed and early permanent dentition. 180 panorama of 6 to 13-year-old boys and girls were analyzed and PiView(Infinitt, Korea) program was used.The horizontal position of the mental foramen was evaluated by the relative position of the teeth. The vertical position of the mental foramen was evaluated by the ratios between the distance from the center of the mental foramen to the inferior border of the mandible and the distance from to the alveolar crest to the inferior border of the mandible.The mental foramen was horizontally located in the anterior aspect of the second primary molar(premolar), and vertically slight below the half of mandibular body. As the age increased, it moved to the posterior and the downward and showed a significant correlation with age.
Adolescent ; Child ; Dentition, Permanent ; Female ; Humans ; Mandible ; Tooth

This study aimed to investigate the correlation between maxillary canine's dental maturity and skeletal maturity of growing children. Cephalometric radiographs, hand-wrist radiographs and panoramic radiographs of 299 children aged 6 – 17 years were analyzed to measure the cervical vertebral maturation stages (CVMS), skeletal maturity indicators (SMI) and Demirjian index (DI). Spearman correlation test was used to analyze the correlation between dental maturity and skeletal maturity.There was significant positive correlation between the DI and CVMS in both boys and girls (p = 0.000). Similarly positive correlation was found between the DI and SMI (p = 0.000).The results of this study suggest that the dental maturity of maxillary canine can be used as auxiliary maturity indicator in growing children.
Child ; Female ; Humans

The purpose of this study was to evaluate polymerization of TheraCal LC, one of the tricalcium silicate cements. To measure the Vickers hardness number (VHN), the specimens were cured at different light curing time and distance.As a result, the VHN of the upper surface was significantly higher than the lower surface's in all groups (p < 0.05). The VHN of the lower surface was increased significantly with the increase of the light curing time in all distance (p < 0.05). When the distance was more than 4.0 mm at all light curing time, the VHN of lower surface was significantly decreased (p < 0.05). When the specimen was light cured for 20 seconds, the VHN of the lower surface did not exceed 2, which corresponds to 10% of the upper surface's.These results suggested that the 20 second light curing time was not sufficient to polymerize the lower surface under specific conditions and that light-curing time should be increased.
Hardness ; Polymerization ; Polymers ; Silicates

The purpose of this study is to investigate factors influencing the upper airway dimensions in skeletal Class Ⅱ children and adolescents.
In total, 67 patients were selected. Airway volume and minimal cross-sectional area were three-dimensionally assessed. Craniofacial morphology and skeletal maturity were assessed on generated two-dimensional cephalograms. The measurements were analyzed using Mann-Whitney test, one-way ANOVA, Pearson’s correlation, and multiple regression analysis.
Upper airway dimensions were significantly smaller in pre-peak stage group, and positively associated with age. Anterior facial height and age were the most relevant factors for airway volume. Mandibular width and age were the most relevant factors for minimal cross-sectional area.
Upper airway dimensions were significantly associated with age, skeletal maturity and craniofacial morphology in all three planes.

The purpose of this retrospective study was to evaluate the skeletal and dental maturity according to the vertical facial type and sex in Korean children in the developmental stage.
In total, 184 participants aged 8 - 14 years were selected and divided into three groups based on the mandibular plane angle. For the comparison between the sexes, the three groups were each divided into male and female subgroups. The skeletal and dental maturity were assessed using lateral cephalograms, hand-wrist radiographs and panoramic radiographs.
The vertical growth group showed significantly greater cervical vertebral and hand-wrist maturity than that in the horizontal growth group. Dental maturity was the highest in the vertical growth group. Girls showed greater skeletal maturity than boys, and no distinct difference was observed between the dental maturity of the sexes.
Analysis of the vertical facial type in children can provide ancillary indicators that may help determine the optimal timing for orthodontic treatment initiation. Earlier initiation of orthodontic treatment may be considered for patients with vertical facial growth patterns.

This study aimed to investigate the correlation between the inclinations of the incisors and lips in mixed dentition aged 7 – 11 years. Lateral cephalometric radiographs of 353 children were analyzed to measure the upper incisor inclination, lower incisor inclination, lower-nasolabial angle, and mentolabial angle in relation to the skeletal malocclusion classification. The measurements were then assessed using the Kruskal-Wallis test, Pearson correlation, and multiple regression analysis.There were significant negative correlations between the inclination of the upper incisors and lower-nasolabial angle in all classes of skeletal malocclusion. There was a negative correlation between the inclination of the lower incisors and mentolabial angle; however, class Ⅱ malocclusion had a significant positive correlation.This study identified the factors that affect lip inclination and verified their associations.
Child ; Classification ; Dentition, Mixed ; Humans ; Incisor ; Lip ; Malocclusion

The purpose of this study was to investigate pediatric emergency department visits patterns and characteristics of children and adolescents under the age of 20 in South Korea from 2002 to 2015 due to dental conditions. This study used a stratified sample of approximately 1 million people from the Health Insurance Review and Assessment Service Database. The age, region, household income, and treatment cost were included for the patient characteristic analysis. Pediatric patients were compared to the adult group (over 20 years old).In children and adolescents, the rate of emergency department visits due to dental conditions was higher for traumatic conditions than for non-traumatic conditions. Children and adolescents with higher household income visited the emergency department more often than those with lower household income. The region with the highest number of children and adolescents visiting the emergency department for dental conditions was Busan (per 100,000 population).Although this study could not confirm the annual trend of children and adolescents’ dental emergency visits due to the sample size limitation, the characteristics of children and adolescents’ dental emergency visits were compared with those of adults using a stratified sample.