• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.2
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• pp.157-166
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• 2020

The first dental visit is recommended at the time of the eruption of the first tooth and no later than 12 months of age. However, even before the age of 1, children can visit the dental hospital for various reasons. The purpose of this study was to analyze the reasons for the dental visit of infant. From January 2006 to December 2015, medical records of infants who visited the Department of Pediatric Dentistry of Kyung Hee University were analyzed. The total number of patients was 419 (238 males and 181 females). The reasons for the dental visits were trauma (47.5%), natal/neonatal tooth (19.8%), dental caries (8.1%), teething problem (4.3%), abnormal frenum (3.6%), soft tissue swelling (3.6%), Bohn's nodule (3.3%), cleft lip and palate (2.9%), gingival neoplasm (1.9%), tongue ulceration (1.7%), oral examination (1.4%), enamel hypoplasia (1.2%) and abnormal temporomandibular joint sound (0.7%). According to this study, there were various oral diseases that could occur in infants. Since infants are usually cared by caregivers, pediatricians, and obstetricians, education of oral diseases of infants is needed to manage the oral symptoms properly.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.187-193
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• 2014

Dental caries are one of the most common oral diseases and Streptococcus mutans (S. mutans) plays an important role in the initiation and progression of dental caries. Oral malodor is primarily the result of microbial metabolism such as Porphyromonas gingivalis (P. gingivalis) that produce volatile sulfur compounds (VSCs), causing oral malodor. Prevotella intermedia (P. intermedia) is known as typical periodontopathic bacteria, and periodontal disease is chronic inflammatory disease that leads to damage of gingival connective tissue and alveolar bone, eventually loss of teeth. In this study, we investigated antimicrobial effect of mouthwash containing cetylpyridinium chloride (CPC), sodium fluoride (NaF), green tea water extract and pine needles water extract against cariogenic and periodontopathic bacteria sucn as S. mutans, P. gingivalis and P. intermedia. As a result, the reduction ratios of S. mutans and P. gingivalis were 4.00 Log and 4.68 Log reduction for 30 s, and P. intermedia were 2.40 Log reduction for 30 s and 2.70 Log reduction for 60 s. Dentocult SM Strip mutans (SM Strip) provides easy detection of visual data showing a significant inhibition on S. mutans. In conclusion, we expected that mouthwash containing CPC, NaF, green tea water extract and pine needles water extract could help preventing the dental disease like dental caries and oral malodor.

• The korean journal of orthodontics
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• v.14 no.2
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• pp.187-202
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• 1984

There are evidences that exogenous electric currents are capable of enhancing bone formation and resolution, and that the conversion of the bioelectric response to biochemical activity provides the directional component of orthodontic tooth movement. In addition, evidence has implicated cyclic nucleotides in alveolar bone cellular activation mechanism during orthodontic tooth movement. In view of these evidences, this study was performed to investigate the effects of exogenous electric currents on cyclic nuclotide levels in feline alveolar bone and the possible clinical application of electric currents as an additional orthodontic tool. In the first study, three groups of three adult cats were subjected to application of a constant direct current of $10{\pm}2$ microamperes to gingival tissue near maxillary canine noninvasively for 1, 3, and 7 days respectively. In the second study, three groups of three adult cats each were treated by an electric-orthodontic procedure for 1, 3, and 7 days respectively. The left maxillary (control) canine received an orthodontic force of 80gm alone at time of initiation, while the right maxillary (experimental) canine received combined force-electric stimulation (80gm of force and $10{\pm}2$ microamperes of a constant D.C. currents). Alveola, bone samples were obtain from the mesial (tension and/or cathode) and the distal (compression and/or anode) sites surrounding maxillary canines as well as from contralateral control sites. The samples were extracted, boiled, homogenized, and the supernatants were assayed for cyclic nucleotides (cAMP, cGMP) by a radioimmunoassay method. And also the amount of tooth movement was measured in the second study. On the basis of this study, the following conclusions can be drawn: 1. The fluctuation pattern of cyclic nucleotide levels in alveolar bone treated by exogenous electric currents was similar to that treated by orthodontic force. 2. The cAMP levels in alveolar bone of electrically treated teeth significantly elevated above the control values. And of electrically treated teeth, the values of the anode sites were higher than those of the cathode sites. 9. The cGMP levels in alveolar bone of electrically treated teeth elevated above the control values at the initiation phase of treatment, but dropped below the control values at time of termination. And of electrically treated teeth, the values of the cathode sites were higher than those of the anode sites. 4. The rate of tooth movement in teeth . treated by force-electric combination increased with the length of treatment as compared to that treated by mechanical force alone.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.253-268
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• 2012

Full-mouth reconstruction of a patient using dental implants is a challenge if there is vertical and horizontal bone resorption, since this includes the gingival area and restricts the position of the implants. however, hard- and soft-tissue grafting may allow the implants to be placed into the desired position. Although it is possible to regenerate lost tissues, an alternative is to use fixed detachable prostheses that restore the function and the esthetics of the gingiva and teeth. Various material combinations including metal/acrylic, metal/ceramic, and zirconia/ceramic have been used for constructing this type of restoration. Other problems include wear, separation or fracture of the resin teeth from the metal/acrylic prosthesis, chipping or fracture of porcelain from the metal/ceramic or zirconia/ceramic prosthesis, and fracture of the framework in some free-end prostheses. With virtually unbreakable, chip-proof, life-like nature, monolithic zirconia frameworks can prospectively replace other framework materials. This clinical report describes the restoration of a patient with complete fixed detachable maxillary and mandibular prostheses made of monolithic zirconia with dental implants. The occluding surfaces were made of monolithic zirconia, to decrease the risk of chipping or fracture. The prostheses were esthetically pleasing, and no clinical complications have been reported after two years.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.4
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• pp.199-205
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• 2003

The p53 protein was discovered in 1979 as cellular 53-kD nuclear phosphoprotein bound to the large transforming antigen of SV40 virus. $P21^{WAF1/CIP1}$, which has been described as the critical downstream mediator of p53, is known to suppress DNA replication and arrest the G1 cell cycle by quaternary complex with cyclin D, cyclin-dependent kinase(CDK) and proliferating cell nuclear antigen(PCNA). In these days, some studies shows that the p21 can be induced by independent pathways. There are various reports about the expression of p21 (67%.82.4%) in oral squamous cell carcinoma. But these studies are mostly done in malignant tumor not in benign tumor. So we decided to study the expression of p21 in ameloblastoma and the relationship between p53 and p21 as a downstream mediator of p53 in ameloblastoma. We investigated the expression of p21 and p53 with the method of immunohistochemistry. We selected 30 cases of ameloblastoma tissue blocks (acanthomatous type: 5 cases, follicular type: 8 cases, plexiform type: 17 cases) imbedded in paraffin. We used 30 cases of normal gingival tissues and 30 cases of squamous cell carcinoma tissues (SCC) respectively and compared their results with those of ameloblastoma. We made slides with the streptavidin-biotin methods and used monoclonal antibody DO-7 (Novocastra, Newcastle, United Kingdom) as p53 antibody and monoclonal antibody M7202 (DAKO, California, U.S.A.) as p21 antibody. We used Pearson's correlation coefficient to analyse the relationship. The results were as follows: 1. p21 was expressed in ameloblastoma about 30% and this is lower than that of normal gingiva and SCC. 2. In normal gingiva and ameloblastoma, p21 expression was correlated with p53 expression. 3. In SCC, p21 were expressed about 83.3% and this is more than that of p53. But there was no correlation between p21 and p53 expression. We confirmed p21 expression and relation with p53 in ameloblastoma. But, to confirm the function of p21, more studies about p21 expression in malignant ameloblastoma and ameloblastic carcinoma are needed.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.529-538
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• 1995

It has been believed that the increased release of free oxygen radicals ($O_2^-,H_2O_2$, and $OH^-$) might be a factor in the pathogenesis of periodontal diseases. Antioxidant enzymes such as glutathione peroxidase(GSH-PX) and catalase can protect the tissue damage from the $H_2O_2$. In order to investigate the GSH-PX and catalase activity in the blood plasma and red blood cells(RBCs) of the patients with periodontitis, 19 patients who had good general health, attachment loss more than 6 mm and bone loss were selected as periodontitis group, 7 patients who had severely inflamed gingiva were selected as gingivitis group, and 15 volunteers with good general and periodontal health were selected as normal group. 17 of 26 patients were performed scaling and root planing to reduce the gingival inflammation for gingivitis and periodontitis groups, and were selected as posttreatment group. After blood plasma and RBCs were collected and separated 1 ml of peripheral blood from each subject, GSH-PX activity in blood plasma and RBCs was measured by the same method that Stefan et al. did, and catalase activity in RBCs was measured by the same method that Beers et al. did. The difference of GSH-PX and catalase activity between normal, gingivitis, and periodontitis groups was statistically analyzed by ANOVA with SPSS/PC+ program, and the difference between pretreatment and posttreatment groups was analyzed by Student t-test. The results were as follows : 1. GSH-PX activity in blood plasma was significantly lower in the gingivitis group($0.8683{\pm}0.0658$), periodontitis group($0.7130{\pm}0.1333$) than in the normal group($1.0241{\pm}0.0801$)(p<0.05), and GSH-PX activity in RBCs was significantly lower in the gingivitis groupt. $0.8156{\pm}0.1167$), periodontitis group($0.7533{\pm}0.1185$) than in the normal group($l.1963{\pm}0.2044$)(P<0.05), but there was no statistical significance in the difference of GSH-PX activity in RBCs between the gingivitis group and periodontitis group(p>0.05). 2. Catalase activity in RBCs was siginficantly lower in the periodontitis group($117.34{\pm}35.01$) than in the normal group($l52.38{\pm}32.09$)(p<0.05). 3. GSH-PX activity in blood plasma was significantly increased in the posttreatment groupe $1.0376{\pm}0.2820$) compared to the pretreatment group(0.7608 0.1600) (p<0.05), and GSH-PX activity in RBC was significantly increased in the posttreatment group($1.0421{\pm}0.2330$) compared to the pretreatment group($0.7728{\pm}0.1210$)(p<0.05). 4. There was no statistical significance in the difference of catalase activity in RBCs between the pretreatment group($112.04{\pm}43.65$) and posttreatment group($l33.41{\pm}39.16$)(p>0.05).The results, within the limits of the present experiment, suggest that the lowered activity of GSH-PX and catalase in blood plasma and RBCs may be related with periodontopathogenesis.

• Journal of Periodontal and Implant Science
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• v.37 no.1
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• pp.35-44
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• 2007

Periodontal ligament (PDL) is the connective tissue located between the tooth root and alveolar bone. In a previous study, PDLs22 was isolated as a PDL-specific gene by using subtractive hybrid-ization between cultured PDL fibroblasts and gingival fibroblasts. It was also suggested that PDLs22 plays important roles in the development, differentiation and maintenance of periodontal tissues. However, little is known about functional study of PDLs22 using recombinant protein in PDL fibroblast differentiation and periodontium formation. In this study, in order to produce the PDLs22 recombinat protein, PDLs22 expression vector were constructed and expressed its protein in various host cell and temperature conditions. The results were as follows: 1. PDLs22 protein was not strongly expressed In the induction system using pRSET-PDLs22 construct. 2. When the BL21(DE3) pLysS was used as a expression host, PDLS22 protein was strongly ex-pressed in the induction system using pHCEIIBNd-PDLs22 construct. 3. The PDLs22 protein was recognized at a molecular weight of 28 kDa in western blots. 4. Almost of the expressed PDLs22 protein was not soluble and observed like as inclusion body. 5. The protein solubility was not improved after modification of induction time and temperature during PDLs22 protein production. In this study, the system for the PDLs22 protein production was connstructed. However, the re-results suggest that further studies will be needed to produce the considerable amount of PDLs22 re-combinat protein, which can use for the periodontal regeneration.

• Korean Journal of Microbiology
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• v.48 no.1
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• pp.52-56
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• 2012

The aim of this study was to evaluate the antimicrobial effect of carvacrol against periodontopathic and cariogenic bacteria and its cytotoxicity in human oral tissue cells. We tested their antibacterial properties against mutans streptococci and five major periodontopathic bacterial species involved in periodontal disease. The antimicrobial activity was evaluated by the minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The cell viability of carvacrol on normal human gingival fibroblast (NHGF) cells was tested by metyl thiazolyl tetrazolium assay. The data showed that carvacrol had remarkable antimicrobial effect on tested bacteria with a MIC and MBC values ranged from 16 to $128{\mu}g/ml$ and from 32 to $128{\mu}g/ml$, respectively. In cell toxicity studies, carvacrol had significantly decreased cell viability when NHGF cells were treated at $128{\mu}g/ml$. These findings suggest that carvacrol has a strong antimicrobial activity against periodontopathic and cariogenic bacteria. However, in order to use it as a component of gargling solution or toothpaste, its concentration should be below $64{\mu}g/ml$ and other compounds having an antimicrobial activity against periodontopathic and cariogenic bacteria should be used together.

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.577-577
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• 2001

The lastest concepts in bonding are "total etch", in which both enamel and dentin are etched with an acid to remove the smear layers, and "wet dentin" in which the dentin is not blown dry but left moist before application of the bonding primer. Ideally, the application of a bonding agent to tooth structure should be insensitive to minor contamination from oral fluids. Clinically contaminations such as saliva, gingival fluid, blood and handpiece lubricant are often encountered by dentists during preparation of a restoration. The aim of this study was to evaluate the effect of contamination by hem-ostatic agents on shear bond strength of compomer restorations. One hundred and ten extracted human maxillary and mandibular molar teeth were collected. The teeth were cleaned from soft tissue remnant and debris and stored in physiologic solution until they were used. Small flat area on dentin of the buccal surface were wet ground serially with 400, 800 and 1200 abrasive paper on automatic polishing machine. The teeth were randomly divided into 11 groups. Each group was conditioned as follows: Group 1 : Dentin surface was not etched and not contaminated by hemostatic agents. Group2 : Dentin surface was not etched but was contaminated by Astringedent (Ultradent product Inc., Utah, U.S.A.). Group3 : Dentin surface was not etched but was contaminated by Bosmin (Jeil Phann, Korea.). Group4 : Dentin surface was not etched but was contaminated by Epri-dent (Epr Industries, NJ, U.S.A.). Group5: Dentin surface was etched and not contaminated by hemostatic agents. Group 6 : Dentin surface was etched and contaminated by Astringedent. Group7 : Dentin surface was etched and contaminated by Bosmin. Group8 : Dentin surface was etched and contaminated by Epri-dent. Group9 : Dentin surface was contaminated by Astringedent. The contaminated surface was rinsed by water and dried by compressed air. Group10 : Dentin surface was contaminated by Bosmin. The contaminated surface was rinsed by water aud dried by compresfed air. Group 11 : Dentin surface was contaminated by Epri-dent. The contaminated surface was rinsed by water and dried by compresfed air. After surface conditioning, F2000 was applicated on the conditoned dentin surface. The teeth were thermocycled in distilled water at $5^{\circ}C\;and\;55^{\circ}C$ for 1000 cycles. The samples were placed on the binder with the bonded compomer-dentin interface parallel to the lmife-edge shearing rod of the Universal testing machine(Zwick 020, Germany) running at a cross head speed of 1.0mmimin. There were no significant differences in shear bond strength between groups 1 and group 3 and 4, but group 2 showed significant decrease in shear bond strength compared with group 1. There were no significant differences in shear bond strength between group 5 and group 7 and 8, but group 6 showed significant decrease in shear bond strength compared with group 5. There were no significant differences in shear bond strength between group 5 and group 9, 10 and 11.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.419-429
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• 2000

Prevotella intermedia has been implicated as a potent pathogen in many kinds of periodontal, pulpal and periapical diseases. However, it has been isolated from periodontally healthy adults and from edentulous children as well. The intraspecies heterogeneity of Prevotella intermedia has been demonstrated in early studies and finally Shah & Gharbia confirmed the existence of 2 DNA homology groups and proposed dividing Prevotella intermedia into 2 species, Prevotella intermedia and Prevotella nigrescens. This study was designed to examine the frequency of Prevotella intermedia and Prevotella nigrescens in diseased periodontal pockets and healthy gingival sulcus of Korean people by PCR based on 16s ribosomal DNA sequence. One hundred adults who had adult periodontitis but not taken any periodontal treatment or antibiotics during previous 6 months and 50 adults who had healthy periodontal tissue were selected for this study. The sulcular fluid was collected into VMGA by sterilized paper point and diluted to 1,000 times in anaerobic chamber. $100{\mu}{\ell}$ of sample was cultured in $37^{\circ}C$ for 10 days. Among the bacterial colonies, BPB were selected and cultured in BHI broth and then Prevotella intermedia was identified through Gram staining and biochemical test. Identified Prevotella intermedia was cultured again and centrifuged. DNA was extracted from the pellet using several reagents. PCR was performed by previously designed primer. The results were followed. 1. BPB were isolated from 39 of 100 samples of diseased periodontal pockets(39%). 2. Prevotella intermedia was identified from 24 of 39 BPB samples. 3. Among 24 Prevotella intermedia, 21 were confirmed as Prevotella inter - media(87.5) and 2 were confirmed as Prevotella nigrescens(8.33%). 4. BPB were isolated from 9 of 50 samples of periodontally healthy patients. Among them only two were identified as Prevotella intermedia, that is, one was confirmed as Prevotella intermedia and the other was Prevotella nigrescens.