• Journal of the korean academy of Pediatric Dentistry
• /
• v.29 no.2
• /
• pp.189-195
• /
• 2002

In the area of pediatric dentistry, several behavior modification techniques have been attempted to relieve young patients' dental fear. The use of audio-visual(AV) aids is one of them and is increasing. In this study, several patients' reactions to dental treatment have been investigated after using AV aids, including patients' sleep, movement, crying and overall behavior. The effectiveness of AV aids have also been investigated through patients' age, previous dental experience and daily exposure to TV or video. Thirty healthy children with Frankl behavior rating (+) or (-) were included in this study. The average age of the children was $52.9{\pm}12.7$ months and no statistical difference was found between the two groups. Thirty patients were equally divided into two groups. Group I(control) received dental treatment with the conventional tell-show-do while group II(AV) with tell-show-do and AV aids. All patients received only restorative dental treatment and received no extraction. Houpt behavior rating scale was used to evaluate patients' behavior during the dental treatment. As a result, there was no significant difference between the two groups in movement and crying. However, more patients in the AV group fell asleep during the dental treatment compared to the control group. Within the AV group, patients with previous dental experience, older age and frequent exposure to AV materials showed better overall behavior during the dental treatment as audio-visual aids were used for behavior management.

• The korean journal of orthodontics
• /
• v.30 no.1 s.78
• /
• pp.115-126
• /
• 2000

Dental arch expansion is one of the method used to solve the dental crowding problem by non-extraction. Many formulae using tooth size have been suggested to predict ideal inter-premolar and inter-molar width. The purpose of this study was to evaluate the adequacy of some upper dental arch width prediction methods, namely Pont's method, Schmuth's method and Cha's method. The sample consisted of the casts of 119 Korean young adults who had no muscular abnormality, no skeletal discrepancy, and Angle's Class I molar relationships. Measurements were obtained directly from plaster casts; they Included mesiodistal crown diameters of the four maxillary incisors, as well as maxillary inter-first-premolar and inter-first-molar arch widths as specified by Pont. The correlation coefficients between the sum of incisors(SI) and upper dental arch width were calculated. The differences between predicted width and actual width were classified as overestimated, properestimated, and underestimated. The data obtained from each group were analyzed for statistical differences. The results were as follows : 1. Upper dental arch width indices were calculated from SI in normal occlusion (81.96 : premolar index, 62.55 : molar index). 2. Low correlations between SI and arch width were noted in normal occlusion (0.50 in the inter-premolar width, 0.39 in the inter-molar width). 3. Pont's formula and Schmuth's formula tended to overestimate the inter-premolar width. A more even distribution of estimates was noted in Cha's fomula. 4. Cases within $\pm$1 mm range of observed inter-premolar width were $45\%$ in the Cha's formula, $40\%$ in the Pont's formula, and $39\%$ in the Schmuth's formula. 5. All formulae had a tendency to underestimate the inter-molar width, but Cha's formula had better predictability than others. 6. Cases within $\pm$1 mm range of observed inter-molar width were $40\%$ in the Cha's formula, $29\%$ in the Pont's formula, and $13\%$ of Schmuth's formula. The data presented in this study does not support the clinical usefulness of ideal arch width prediction methods using the mesiodistal width of maxillary incisors.

• The korean journal of orthodontics
• /
• v.40 no.2
• /
• pp.87-94
• /
• 2010

Objective: Many studies have carried out research on comparisons between laser etching and conventional etching systems to investigate methods of reinforcing shear bond strength. The purposes of this study were to assess the efficiency of bonding with erbium, chromium doped: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser etching combined with the conventional etching technique. Methods: Sixty-four sound premolars, extracted for orthodontic purposes, were randomly divided into 4 groups and treated in the following manner. First group, conventional etching of 37% phosphoric acid for 15 seconds (control); second group, 1.5 W laser etching for 10 seconds followed by conventional etching; third group, conventional etching followed by 1.5 W laser etching; fourth group, 1.5 W laser etching for 15 seconds only. We assessed the shear bond strength, the surface characteristics, and the adhesive remnant index scores between all groups. Results: Experimental groups showed higher shear bond strength than the control group. But no statistically significant differences were found between the second and third groups. Adhesive remnant scores were compared with the Kruskal-Wallis test, and no statistically significant differences were found between all groups. Conclusions: To obtain maximum shear bonding strength, a combined technique of Er,Cr:YSGG and 37% phosphoric acid is useful even though it may be inconvenient.

• The korean journal of orthodontics
• /
• v.40 no.4
• /
• pp.260-266
• /
• 2010

Objective: The aim of this study was to determine whether different types of adhesive systems and enamel-protective agents will affect the tensile bond strength of lingual brackets. Methods: A total of 75 extracted mandibular incisors were randomly divided into 5 groups and lingual brackets were bonded. Group 1 specimens received Transbond XT (3M Unitek, Monrovia, CA, USA), Group 2 required the application of a fluoride-releasing resin (Ortho-coat, Pulpdent, Watertown, MA, USA) with Transbond XT, Group 3 specimens received a chlorhexidine varnish (Cervitec Plus, Ivoclar Vivadent, Schaan, Lichtenstein) with Transbond XT. In Group 4, a light-cured orthodontic adhesive (Aegis Ortho, Bosworth, Skokie, USA) was applied and in Group 5, an antimicrobial self-etching primer (Clearfil Protect Bond, Kuraray, Osaka, Japan) was used. Results: There were no significant differences in bond strength whether fluoride-releasing resin or chlorhexidine varnish were used or not. Group 5 had significantly higher bond strength and adhesive remnant index (ARI) values than other groups (p < 0.001). The application of enamel-protective products did not have an adverse affect on the bond strength of lingual brackets. Conclusions: These products might provide benefits both for the patient and the clinician, by supporting the oral hygiene during lingual orthodontic treatment. The higher ARI score may be beneficial for Clearfil Protect Bond but its excessive bond strength should be considered in clinical practice, especially where the enamel is thin.

• The korean journal of orthodontics
• /
• v.41 no.1
• /
• pp.16-24
• /
• 2011

Objective: The purpose of this study was to determine (1) the shear bond strength (SBS) of an antimicrobial monomer-containing self-etching primer according to ceramic bracket types and (2) the bracket-adhesive failure mode using an adhesive remnant index (ARI). Methods: A total of 90 extracted human teeth were randomly divided into 6 groups. Each group consisted of one of two ceramic brackets (monocrystalline, polycrystalline) and one of three primers (Transbond XT primer, Transbond Plus SEP, Clearfil Protect Bond) with each group containing 15 specimens. The SBS was measured, and adhesive residues left on the tooth surface were assessed. Results: The SBS of polycrystalline ceramic bracket groups was Significantly higher than that of the monocrystalline ceramic bracket groups (p < 0.001). The SBS of Transbond XT primer groups was significantly higher than those of Transbond Plus SEP groups and Clearfil Protect Bond groups (p < 0.001). All the groups showed bonding failures between the bracket base and adhesive. Conclusions: The combination of a self-etching primer with a monocrystalline bracket is recommended for clinical use, considering its acceptable SBS and mode of failure.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.47 no.3
• /
• pp.248-256
• /
• 2020

This study aimed to evaluate the effects of national dental screening for children in Korea in the aspects of prevention of dental caries, the number of treatments related to dental caries, and cost of dental care. The study used the national cohort data on children health screening provided by National Health Insurance Service, and analyzed 32,937 1st dental screening, 22,608 2nd dental screening, 13,708 3rd dental screening, and 241,043 cases from the dental care of 27,944 children born in year 2008 and 2009. The decayed-filled teeth index and decayed-filled person rate, calculated from the results of the 2nd and 3rd dental screening, decreased as the number of preceding dental screening increased. Glass ionomer and amalgam restoration, pulp treatment of primary teeth and extraction of primary canine and molar were shown to decrease as the number of examined dental screening increased, and the total cost of dental care covered by national health insurance also decreased as the number of dental screening increased. In conclusion, national dental screening for children is an efficient and economical oral health care method that prevents dental caries and lowers the possibility of dental caries related treatment, thereby reducing cost of dental care.

• The korean journal of orthodontics
• /
• v.36 no.3 s.116
• /
• pp.198-206
• /
• 2006

With the introduction of the xenon plasma arc curing light and the LED curing light as orthodontic curing lights, the polymerizing time of orthodontic composites has clearly decreased. In contrast to various research cases regarding the polymerization time and bond strength of the xenon plasma arc curing light, not enough research exists on the LED curing light, including the appropriate polymerization time. The objective of this research was to compare the bond strength of the plasma curing light and the LED curing light in regards to the polymerization time. The polymerization time needed to achieve an appropriate adhesion strength of the bracket has also been studied. After applying orthodontic brackets using composite resin onto 120 human premolars, the plasma arc curing light and the LED curing light were used for polymerization for 4, 6, and 8 seconds accordingly. This research proved that the LED curing light provided appropriate bond strength for mounting orthodontic brackets even with short seconds of polymerization. The expensive cost and large size of the device limits the use of the plasma arc curing light, whereas the low cost and easy handling of the LED curing light may lead to greater use in orthodontics.

• Journal of dental hygiene science
• /
• v.5 no.1
• /
• pp.13-17
• /
• 2005

This research was conducted in order to collect and arrange an oral health information needed the school oral hygiene as a part of a long term local community oral hygiene development to promote the oral health of the residents in Sung-Nam. After gathering the information of oral hygiene of 12-year old schoolchildren in Sung-Nam, these conclusions are reached: (1) The experience of dental caries in permanent teeth of 12-year old schoolchildren in Sung-Nam was revealed 74.7%, proportion of children with one or more caries in permanent teeth was 36.2%, and DMFT index was 2.75. (2) DT rate was 28.4% in total and regional difference has been revealed. In Sujung-Gu, DT rate was 36,8% and this was nearly as twice as 19.8% in Bundang-Gu. (3) For permanent teeth, fillings requirements for one surface were 26.6%, more that two surfaces were 13.3%. In addition, artificial crown treatment requirements were 1.8%, dental pulp treatment was 5.3%, and extraction requirement was 2.2%. In contrast, holders of pit and fissure sealant were only 27.1%. (4) In Sung-Nam, oral hygiene education campaign for 12-year old schoolchildren needs to be continued. Simultaneously, early stage examination and preventive approaches for decayed teeth such as pit and fissure sealant need to be considered for schoolchildren who have high tendency of dental caries and who are in areas which show high percentage of dental caries occurrence.

• Journal of dental hygiene science
• /
• v.16 no.5
• /
• pp.349-354
• /
• 2016

The purpose of this study was to evaluate the efficacy of the newly-developed $Qraypen^{TM}$ (All In One Bio, Korea) system for the diagnosis of early proximal caries by comparing it with the conventional methods of visual inspection and periapical radiography. This study was carried out from July 2015 to April 2016 targeting 32 children aged 7~12 years who visited Y-Dental Clinic for school oral health examinations. Two investigators selected and examined a total of 153 primary molars that had not undergone restorative treatment. Comparisons were carried out between visual inspections, readings of posterior periapical radiography images, and readings of $Qraypen^{TM}$ images. This study revealed that the percentage of interproximal surfaces of primary molar teeth without caries incidence was 83.7% using $Qraypen^{TM}$ imaging and 84.9% using visual inspection and periapical radiography. The differences between the two methods were not statistically significant. Thus, $Qraypen^{TM}$ is expected to be a useful and convenient auxiliary diagnostic device that can facilitate the detection of hidden proximal caries in primary molars.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.48 no.1
• /
• pp.50-63
• /
• 2021

Microcephalic osteodysplastic primordial dwarfism type II (MOPD II) is an autosomal recessive inherited disorder form of primordial dwarfism, caused by mutations in the pericentrin gene. The purpose of the study was to examine the clinical and radiological features, physicochemical properties and microstructures of the tooth affected with MOPD II. The mandibular 2nd molar was collected from the MOPD II patient. Micro-computerized tomography, scanning electron microscopy, energy dispersive spectrometry and Vickers microhardness analysis were performed on the MOPD II and the normal control. The morphology of the MOPD II tooth appeared to have malformed pulp and root and showed a small size. The mineral density measurement showed that the MOPD II tooth had similar scores in the enamel, but lower scores in the root 1/2 and apical dentin compared to the normal control. The microhardness values were smaller in the cusp enamel, root 1/2 dentin and apical dentin of the MOPD II compared to the normal control. In this study, the dental characteristics and the physicochemical properties of a tooth affected with MOPD II were analyzed to improve understanding of the oral manifestations of the disease and to assist in proper dental treatment by identifying precautions.