• The Journal of the Korean dental association
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• v.55 no.2
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• pp.156-164
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• 2017

Purpose: The aim of this in vitro study was to assess changes in remineralization by stimulated human saliva over a short period of 48 hours with quantitative light-induced fluorescence (QLF) technology. Materials and Methods: Bovine incisor surfaces were demineralized for 10 days. Two types of stimulated saliva were collected from 7 healthy persons. 24 hours after tooth brushing (Stimulated saliva group) and immediately after tooth brushing with 1,000 ppm NaF dentifrice (Dentifrice saliva group). The specimens were immersed in saliva and fluorescence images were obtained by QLF-digital (QLF-D $biluminator^{TM}$,) at 2, 4, 6, 12, 24, and 48 hours fluorescence loss (${\Delta}F%$) of the lesions. A paired t-test was performed to assess fluorescence differences between before (${\Delta}F_{baseline}$) and after (${\Delta}F_{treatment\;time}$) the remineralization process. Results: Before the remineralization, the mean ${\Delta}F_{baseline}$ of the initial demineralized specimens was $-18.42{\pm}0.15$ (%). In both groups, the ${\Delta}F$ values obtained at baseline and after 2 hours were statistically significant (P < 0.001), indicating recovery of the lesions by approximately 40% after 2 hours. After 48 hours, remineralization rates were slightly higher (49%) for the stimulated saliva group than for the dentifrice saliva group (41%), but the difference was not statistically significant. Conclusions: With QLF minute degrees of remineralization by saliva can be measured in periods as short as 2 hours. Additionally no significantly higher effects of remineralization were observed in the dentifrice saliva group when compared to the stimulated saliva group.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.617-623
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• 2004

Acidic drink has been known as a cause of tooth erosion. The purpose of this study is to verify the acid levels of orange juices in market and evaluate the erosion effects on the enamel of deciduous teeth by orange juices in relatively short period of time. With four kinds of orange juice selected from market, pH, buffering capacity and concentration of Ca and P ion were measured. And forty segments of normal enamel of deciduous incisors were divided into four groups and level of erosion was measured by surface hardness test before and after soaking at 50ml of orange juice for 10 minutes. The results of this study showed that the average pH of orange juices was 4.0 and this pH value was so acidic as to cause the tooth erosion. There were differences in small quantity for each group of teeth, however, the result was statistically so significant that orange juices can cause enamel erosion in relatively short period of time.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.2
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• pp.176-187
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• 2020

The purpose of this study is to evaluate validity, reliability and reproducibility of tooth width (TW), arch length (AL) and arch length discrepancy (ALD) measured on a digital model taken via 3-dimensional model scanner and intraoral scanner compared to a plaster model. A total of 30 patients aged 12 to 18 were eligible for the study. 3 types of models were acquired from each patient: a conventional plaster model (P), a model scanned digital model (MSD) taken via Freedom UHD^® and an intraoral scanned digital model (ISD) taken via CS3600^® in-vivo. The reliability of TW and AL in each group was evaluated using Pearson's correlation coefficient, while the reproducibility was evaluated with intraclass correlation coefficient. The validity of space analysis was assessed by paired t-test. As a result, all measurements of P, MSD and ISD groups showed favorable reliability and reproducibility. Most of measurements for space analysis in MSD group and TW in ISD group also presented high validity. AL and ALD presented statistically significant difference between P and ISD group. The validity of measurements of space analysis in ISD group was short in doubt to valid, but clinically acceptable. Both MSD and ISD are clinically acceptable to use for space analysis but clinician should be aware that errors can be found using a digital model.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.4 no.2
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• pp.82-87
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• 2008

Cleidocranial dysplasia (CCD) is an autosomal dominant skeletal dysplasia and is caused by mutation in the CBAFA1 gene of 6p21 chromosome band. Patients with CCD express skeletal dysplasia such as hypoplastic/aplastic clavicle, brachycephalic skull, midface hypoplasia and moderate short stature. In addition to skeletal dysplasia, specific symptoms may appear in respiratory organs, auditory area, and the more distinguished, dentition. Dental findings include: delayed eruption of permanent tooth, multiple supernumerary tooth more than five, malocclusion, etc. In Patients presenting excessive SNT, complications of SNT could be prevented and will be managed through pertinently timed treatment such as tooth extraction, using space maintainer, and orthodontic management after early diagnosis. This case is about the treatment of eruption disorders in permanent teeth owing to SNT in CCD patients, who are three family members in the $3^{rd}$ generation inherited from maternal grandfather through atavism. We performed the extraction of numerous SNT and orthodontic treatment on them in this case. On evaluating panoramic and cephalometric views, some classical signs of skeletal dysplasia due to CCD were recognized in a pool of three patients, the clavicle was distinctively displayed in all patients.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.7 no.1
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• pp.25-28
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• 2011

Autism is a developmental, neuropsychiatric disorder that begins in early childhood. A patient with autism seen in the dental office frequently may have many complications. Therefore, it may be needed to consider modified or alternative therapy for dental care of autistic patients. This is the case of a 16-year old boy who have autism. He came to the department of the pediatric dentistry, Yonsei University Dental Hospital, for evaluation and treatment of dentigerous cyst associated with impacted teeth(#33,34,35). Under daily hospitalization and general anesthesia, the cyst was enucleated with surgical extraction of #34 and autotransplantation of #33,35. And during the periodic dental followup, apexification of #33,35 was performed for periapical lesion and root maturity. At 2 year 6 months follow- up, now, bony healing was completed and there are some complications like external resorption of #33 and space loss of #34 area. Generally, the marsupialization has been widely recommended for treatment of dentigerous cyst. However, in this case, there is a little possibility of spontaneous eruption after marsupialization considering of patient's age, location and angulation of the impacted tooth, root maturity. And there is necessity to choose the treatment that has low recurrence risk and needs short-term follow-up for autism. Above all, poor oral hygiene and lack of cooperation for decompression treatment is a matter of primary consideration. Consequently, enucleation of the cyst was chosen for the final treatment plan in this case. It is important to consider the conditions that affect the eruption of a dentigerous cyst-associated tooth to predict the successful eruption and special health care needs of the patient when the treatment plan is settled.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.761-776
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• 2005

The purpose of the present study was to examine the relationship between the form of the clinical crowns in the maxillary anterior segment and the clinical feature of gingiva such as morphological characteristics and the gingival thickness. Fifty periodontally healthy subjects were clinically examined regarding the probing depth, the thickness of the free gingiva, and the width of the keratinized gingiva. From study models of the maxillary anterior region, the width at cervical third(CW) and the length(CL) of the clinical crown, the papillary height, and the gingival angle of the 6 anterior teeth were measured. Each tooth was classified into 4 groups (longnarrow, NL; narrow, N; wide, W; short-wide, WS) according to CW/CL ratio and all the data were compared between groups NL and WS using independent t-test. Stepwise multiple regression analysis was performed for each tooth region with the gingival thickness at the level of sulcus bottom, the width of keratinized gingiva, and gingival angle as the dependent variables. As the results, the NL group of the upper anterior teeth displayed, higher papilla height, and narrower keratinized gingiva, more acute gingival angle resulting in pronounced "scalloped" contour of the gingival margin, compared to the WS group. There was no significant difference between groups NL and WS with respect to probing depth and the gingival thickness. The regression analyses demonstrated that the gingival thickness in central incisors was significantly associated to the mesio-distal width and bucco-lingual width of the crown, and labial probing depth. The width of keratinized gingiva was significantly associated with labial probing depth in central incisors and with proximal probing depth and gingival angle in lateral incisors, and with labial and proximal probing depth, and gingival angle in canines. The gingival angle was significantly associated with papillary height and CW/CL ratio and additionally with proximal probing depth in central incisors, with the width of keratinized gingiva in lateral incisors, and with labial probing depth and the width of keratinized gingiva in canines. These results indicate that the form of clinical crown in upper anterior region could influence the clinical feature of gingiva and the influencing factors might be different according to the tooth region.

• Journal of Periodontal and Implant Science
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• v.37 no.4
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• pp.705-718
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• 2007

The purpose of this study was to evaluate 6 years cumulative survival rate (CSR, %) of mandibular posterior single tooth implants replaced with $Br{\aa}nemark$ $TiUnite^{(R)}$ implant system. The findings from this study were as followed ; 1. The 112 (111 persons) single implants that were placed in the mandibular posterior region were successful except 4 cases and showed 96.42% CSR. 2. The 55 (55 persons) single implants that were placed in the mandibular first molar region were successful except 2 cases and showed 96.36% survival rate. And, among the 57 (56 persons) single implants replacing the mandibular second molar. 2. failed showing 96.49% survival rate. There was no significant statistical difference. 3. Among the total 112 implants, 5.0mm wide diameter implants were placed in 96 cases(85.7%) showing 96.9% survival rate. 4.0mm standard diameter implants were placed in 16 cases showing 93.8% survival rate. There was no significant statistical difference. 4. Long implants above 10.0mm length were placed 103 cases(91.0%) and showed 96.1% survival rate. Short implants within 8.5mm length were placed 9 cases and showed 100% survival rate. There was no significant statistical difference. 5. 37 implants placed in type I, II bone quality were showed higher survival rate(100%) than that of 52 implants placed in type III, IV bone quality(92.3%). But, there was no significant statistical difference. In conclusion, $Br{\aa}nemark$ $TiUnite^{(R)}$ implant showed successful results when replacing manbibular single molar.

• Restorative Dentistry and Endodontics
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• v.24 no.4
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• pp.628-632
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• 1999

Currently electronic apex locators have been widely used to determine working length in endodontic treatment. According to Manufacture's recommendation, it is beneficial to find the working length before instrumenting the canal. However, in crown-down pressureless technique, working length of tooth is established following coronal instrumentation 3mm short of radiographic apex. In narrow canals, mechanically formed constriction might be established by coronal instrumentation in some distance from anatomical constriction. The purpose of this study was to evaluate the accuracy of Root-ZX in the canal with mechanical constriction following considerable coronal enlargement with ProFile .06 series. The 40 root canals in 30 extracted mandibular molars were accessed, and their actual length (AL) established by passing a size 10 file just through the minor apical foramen. The teeth were then embedded in an acrylic container with normal saline. The initial canal length(IL) was measured with Root-ZX by negotiating a size 10 file to the apical constriction. The canal was sequentially enlarged to size 40 with ProFile .06 file 3mm short of actual length. The enlarged final canal lengths (FL) were obtained with a size 15 file. The average values of IL, FL were calculated and compared using Repeated measures Analysis of Variance followed Turkey's Studentized Range test. The results were obtained as follows: 1. The initial canal length was 0.12mm shorter than actual canal length(P>0.05). 2. The differences between initial canal length and final canal length were not significant(P>0.05). 3. As a result of this study, regardless of mechanically formed constriction. Root-ZX differentiated between mechanical and anatomic constriction.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.1
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• pp.51-56
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• 2002

Russell-Silver syndrome is a type of intrauterine growth retardation, characterized by short stature noted at birth, hemiatrophy or asymmetry, variation in sexual development and other abnormalities, including cafe-aulait pigmentation and clinodactyly. Facial features commonly associated with this syndrome are a small triangular face, decreased facial height, down-turned corners of the mouth(shark's mouth), a small mandible, and occasionally asymmetry. The major intra-oral features of the syndrome that have been reported are a high-arched palate, delayed tooth eruption, microdontia, hypodontia, and crowding. These cases were diagnosed at birth as Russell-Silver syndrome by clinical features such as prenatal growth retardation, short stature, low body weight, et al., and have been treated with growth hormone. The purpose of this paper is to report the dental findings of two patients and review the pertinent literature through the two cases.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.1-12
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• 2010

The aim of this study was to evaluate the preventive effect of commercially available anticariogenic products, specifically, the tooth cream containing Casein phosphopeptide-amorphous calcium phosphate(CPP-ACP), fluoride varnish and low-level fluoride mouthrinse on enamel erosion induced by carbonated beverage in a short period of time. Enamel specimens were treated as follows and were then kept in artificial saliva for 24 hours followed by further processing by alternately soaking them in Cola beverage and in distilled water for 1 minute each five times. Group 1: control group (no treatment) Group 2: tooth cream with CPP-ACP Group 3: fluoride varnish (1,000 ppm F) Group 4: low-level fluoride mouthrinse (227 ppm F) Group 5: fluoride varnish + tooth cream with CPP-ACP Group 6: low-level fluoride mouthrinse + tooth cream with CPP-ACP Microhardness and erosion depth were measured and the mineral loss of each specimen was evaluated by measuring the volumetric fluorescence change(${\Delta}Q$) against the stable fluorescent grid using quantitative light-induced fluorescence(QLF). The experiment lasted for 6 days repeated each day. The results were as follows: 1. The microhardness was increased as follows: Group $1{\leq}2{\leq}4$<6<$3{\fallingdotseq}5$. 2. The mean erosion depth was increased as follows: Group $5{\fallingdotseq}3$<6<$4{\fallingdotseq}2{\fallingdotseq}1$. 3. The ${\Delta}Q$ was increased as follows: Group $1{\fallingdotseq}2{\leq}4{\leq}6{\leq}3{\fallingdotseq}5$. The decrement of ${\Delta}Q$ was similar between group 1 and 2, group 4 and 6 and group 3 and 5. 4. The ${\Delta}Q$ showed positive correlation with microhardness (r=0.96, p<0.05), while it was negatively correlated to erosion depth (r=-0.96, p<0.05).