• Restorative Dentistry and Endodontics
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• 제25권2호
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• pp.289-298
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• 2000

Carbamide peroxide is usually used for vital teeth bleaching at home. Complications such as tooth hypersensitivity and/or gingival irritation are frequently reported. Therefore, this study was performed to evaluate any possible histological changes in pulp and periodontal tissue by carbamide peroxide bleaching gel in rats. 10% and 15% carbamide peroxide containing nightguard for upper molar were worn for 4 hours a day. The rats were sacrificed after 1 day, 2 days, 3 days, 4 days and 6 days application of carbamide peroxide respectively. The results were as follows : Mild infiltration of inflammatory changes below the junctional epithelium and hyperplasia of epithelium were observed in both 10% and 15% carbamide peroxide treated groups. In all experimental groups, odontoblasts were changed from columnar to cuboidal shape and/or obliterated and the focal loss of predentin was observed in pulp horn. With increasing time of application, these changes were more remarkable, but limited in pulp horn. Inflammatory reactions, vacuolar changes and hyaline degenerations of the pup tissue were also observed in some cases. These results suggested that carbamide peroxide gel used in home bleaching could cause reversible pulpal irritation.

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.487-501
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• 1998

In the case of CAD/CAM ceramic inlay restorations, if isthmus width is widened too much, it may cause fracture of remaining tooth structure or loss of bonding at the luting interface because of excessive displacement of buccal or lingual cusps under occlusal loads. So to clarify the criterior of widening isthmus width, this study was designed to test the tensile bond strength and bond failure mode between dentin and ceramic cemented with luting composite resin cements. Cylindrical ceramic blocks(Vita Cerec Mark II, d=4mm) were bonded to buccal dentin of 40 freshly extracted third molars with 4 luting composite resin cements(group1 : Scotchbond Resin Cement/Scotchbond Multi-Purpose, group2 : Duolink Resin Cement/ All-Bond 2, group3: Bistite Resin Cement/Ceramics Primer, and group4:Superbond C&B). Tensile bond test was done under universal testing machine using bonding and measuring alignment blocks(${\phi}ilo$ & Urn, 1992). After immersion of fractured samples into 1 % methylene blue for 24 hours, failure mode was analysed under stereomicroscope and SEM. Results: The tensile bond strength of goup 1, 2 & 4 was $13.97{\pm}2.90$ MPa, $16.49{\pm}3.90$ MPa and $16.l7{\pm}4.32$ MPa, respectively. There was no statistical differences(p>0.05). But, group 3 showed significantly lower bond stregnth($5.98{\pm}1.l7$ MPa, p<0.05). In almost all samples, adhesive fractures between dentin and resin cements were observed. But, in group 1, 2 & 4, as bond strength increased, cohesive fracture within resin cement was observed simultaneously. And, in group 3, as bond strength decreased, cohesive fracture between hybrid layer and composite resin cement was also observed. Cohesive fracture within dentin and porcelain adhesive fracture were not observed. In conclusion, although adhesive cements were used in CAD/CAM -fabricated ceramic inlay restorations, the conservative priciples of cavity preparation must be obligated.

• Journal of Oral Medicine and Pain
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• 제25권2호
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• pp.235-240
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• 2000

This study was carried out among 34 patients who visited Yonsei Dental Hospital from 1996. 1. to 1999. 5 for trigeminal neuralgia. By studying the patient's treatment prior to visiting our hospital, features of trigeminal neuralgia, treatment process of trigeminal neuralgia, prognosis of treatment, consultation with other professions and involvement of surgery, etc., the results are as follows: 1. 67.7% of onset age range from 40s to 60s, and average age is 50.2. 2. Ratio of right to left involvement is 1:2.1, male to female ratio is 1:1.9. 3. Occurrence rate of each branch is V3(44.1%), V2(11.8%), V1+V2+V3(11.8), V1+V2(8.8%). 4. Treatments prior to admission to our hospital are extraction(5.9%), endodontic treatment(5.9%), medication(11.8%), Oriental Medicine treatment(5.9%). 5. Routes of admittance to our hospital are by their preference(55.9%), local clinic referral(32.4%), E.N.T referral(5.9%), Neurology referral(5.9%). 6. 70.6% of patients treated at our hospital who were relieved of symptoms, were referred to Neurology(66.7%) and Pain Clinic(33.3%) for the reason of relapse, side effects of the drug itself, incomplete relief of pain. 7. 2 patients who were referred to medical part showed brain vessels contacting trigeminal nerve root on Brain MRangiography. But pain is being controlled by medication and no specific surgical procedure was carried out. The results show that 17.7% of patients admitted received inappropriate early treatment. In order to relieve tooth loss and patient's psychologic stress due to inappropriate treatment, precise differential diagnosis must be made among local teeth disease and idiopathic facial pain. Medication may show side effects of the drug itself, incomplete relief of pain or relapse of symptoms. Therefore, to treat trigeminal neuralgia appropriately by drug injection, surgery or radiation therapy, consultations among dentists, neurologists and anesthesiologists are required.

• Imaging Science in Dentistry
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• 제51권3호
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• pp.237-242
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• 2021

Purpose: The aim of this study was to analyse and review deep learning convolutional neural networks for detecting and diagnosing early-stage dental caries on periapical radiographs. Materials and Methods: In order to conduct this review, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA) guidelines were followed. Studies published from 2015 to 2021 under the keywords(deep convolutional neural network) AND (caries), (deep learning caries) AND (convolutional neural network) AND (caries) were systematically reviewed. Results: When dental caries is improperly diagnosed, the lesion may eventually invade the enamel, dentin, and pulp tissue, leading to loss of tooth function. Rapid and precise detection and diagnosis are vital for implementing appropriate prevention and treatment of dental caries. Radiography and intraoral images are considered to play a vital role in detecting dental caries; nevertheless, studies have shown that 20% of suspicious areas are mistakenly diagnosed as dental caries using this technique; hence, diagnosis via radiography alone without an objective assessment is inaccurate. Identifying caries with a deep convolutional neural network-based detector enables the operator to distinguish changes in the location and morphological features of dental caries lesions. Deep learning algorithms have broader and more profound layers and are continually being developed, remarkably enhancing their precision in detecting and segmenting objects. Conclusion: Clinical applications of deep learning convolutional neural networks in the dental field have shown significant accuracy in detecting and diagnosing dental caries, and these models hold promise in supporting dental practitioners to improve patient outcomes.

• 대한치과보철학회지
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• 제59권3호
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• pp.314-318
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• 2021

미만성 경화성 골수염(diffuse sclerosing osteomyelitis, DSO) 환자에서 임플란트를 사용하여 손실된 치아의 회복에 대한 보고는 거의 없다. DSO 환자는 임플란트의 골유착에 불리한 골질을 지니고 있기 때문에 임플란트를 식립할 때, 외과적 외상, 감염 관리 및 연장된 치유 기간과 같은 추가적인 고려사항이 필수적이다. 본 증례는 DSO 환자에서 임플란트 골유착의 실패와 성공에 관한 보고이다.

• 대한치과보철학회지
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• 제59권2호
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• pp.210-219
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• 2021

치아의 과도한 마모는 저작 효율 감소, 교합평면 붕괴 및 안모 변화를 일으킬 수 있다. 수직고경 변화를 동반한 전악 수복의 경우 측두하악관절, 저작근 및 치아의 동통을 유발할 수 있으므로 정밀한 진단과 치료 계획이 요구된다. 본 증례는 69세 남성으로 구치부 지지가 상실된 상태로 과도한 치아 마모 증상을 보이는 상태였다. 가철성 교합안정장치 및 임시보철물로 증가된 수직고경의 적응 정도를 평가하였고, 임플란트를 동반한 지르코니아 고정성 보철물을 이용하여 최종 보철 수복을 진행하였다. 안정적인 전방유도 설정, 적절한 구치부의 이개, 중심위에서 균등한 치아 접촉을 부여하여 기능 및 심미적으로 만족스러운 치료 결과를 보였기에 보고하고자 한다.

• Annals of Geriatric Medicine and Research
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• 제22권4호
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• pp.194-199
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• 2018

Background: The aim of this study was to examine the correlation between the number of remaining natural teeth (NRT) and the appendicular skeletal muscle mass index (SMI) in older adults. Methods: This study was based on data from the 2008-2010 Korea National Health and Nutritional Examination Surveys. The participants were 2,378 older participants (984 men and 1,394 women) aged over 65 years. Survey dentists conducted oral health examinations, and ASM was measured using dual-energy X-ray absorptiometry. Results: The participants with $NRT{\geq}20$ had more ASM and SMI than those with NRT<20 in both sexes. SMI was correlated with NRT in men (r=0.018, p<0.001) and in women (r=-0.007, p<0.001). The positive correlation between the NRT and SMI remained significant in men even after adjusting for age, marital status, income, smoking, drinking, physical activity, protein intake, energy intake, calcium intake, body mass index, fasting blood glucose level, medications, and prostheses (${\beta}=0.011$, p=0.001). In women, the correlation disappeared after adjustment for smoking, alcohol, physical activity, protein intake, energy intake, calcium intake, marital status, income, fasting basal glucose, medication administration, and prostheses. Conclusion: This study showed a correlation between NRT and SMI in those ${\geq}65$ years of age in Korea. The relationship persisted in men, but not in women, even after adjusting for confounders.

• 구강생물연구
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• 제42권4호
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• pp.198-207
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• 2018

Guided tissue regeneration (GBR) has been used to promote new bone formation in alveolar bone reconstruction at defective bone sites following tooth loss. Bone grafts used in GBR can be categorized into autogenous, xenogenous, and synthetic bones, and human allografts depending on the origin. The purpose of this study was to compare the rates of bone regeneration using two different bone grafts in the cranial defects of rabbits. Ten New Zealand rabbits were used in this study. Four defects were created in each surgical site. Each defect was filled as follows: with nothing, using a 50% xenograft and 50% human freeze-dried bone allograft (FDBA) depending on the volume rate, human FDBA alone, and xenograft alone. After 4 to 8 weeks of healing, histological and histomorphometric analyses were carried out. At 4 weeks, new bone formation occurred as follows: 18.3% in the control group, 6.5% in group I, 8.8% in group II, and 4.2% in group III. At 8 weeks, the new bone formation was 14.9% in the control group, 36.7% in group I, 39.2% in group II, and 16.8% in group III. The results of this study suggest that the higher the proportion of human FDBA in GBR, the greater was the amount of clinically useful new bone generated. The results confirm the need for adequate healing period to ensure successful GBR with bone grafting.

• Natural Product Sciences
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• 제26권4호
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• pp.326-333
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• 2020

The aerial parts of Eclipta prostrata is used as a traditional medicine and vegetable. In traditional folk medicine, it is used for treatment of hemorrhages, hepatic, disease, renal injuries, hair loss, tooth mobility, and viper bites. In this study, ten compounds (1 - 10) were isolated from the aerial parts of E. prostrata. A reliable high performance liquid chromatography equipped with photometric diode array detector (HPLC-PDA) method was developed to simultaneously quantitate 10 marker compounds [chlorogenic acid (1), paratensein 7-O-��-ᴅ-glucoside (2), quercetin 7-O-��-ᴅ-glucoside (3), luteolin 7-O-��-ᴅ-glucoside (4), apigenin 7-O-��-ᴅ-glucoside (5), apigenin 4'-O-��-ᴅ-glucoside (6), apigenin (7), luteolin (8), wedelolactone (9), and paratensein (10)]. In addition, compounds 5 and 6 showed considerable inhibitory effects against protein-tyrosine phosphatase 1B (PTP1B) enzyme. Moreover, compounds 6 - 8, and 10 exhibited potent α-glucosidase inhibitory effects with IC50 values of 24.5 ± 1.9, 33.0 ± 0.5, 45.5 ± 0.1, and 23.8 ± 1.0 µM, respectively. All compounds (1 - 10) showed considerable acetylcholinesterase (AChE) inhibitory effects with IC50 ranging from 30.1 to 75.2 µM.

• 치위생과학회지
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• 제21권1호
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• pp.45-51
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• 2021

Background: Periodontal disease, also known as gum disease, is a major dental inflammatory disease with a very high prevalence; it is the main cause of tooth loss. Therefore, diagnostic biomarkers that can monitor gum inflammation are important for oral healthcare. Since the gingival crevicular fluid (GCF) adequately reflects changes in the periodontal environment, they have become a target for the development of effective diagnostic biomarkers for periodontitis. In the present study, the level of the target molecules suggested as diagnostic biomarkers for periodontitis were analyzed in GCF samples collected from healthy individuals and periodontitis patients. In addition, useful targets for the diagnosis of periodontitis were evaluated. Methods: GCF samples were collected from healthy individuals and periodontitis patients using absorbent paper points. SDS-PAGE and Coomassie staining were performed for protein analysis. The protein concentrations of GCF specimens were determined using the Bradford method. The levels of the target molecules appropriate for diagnosing periodontal disease were measured by ELISA, according to the manufacturer's protocol. Results: The protein concentration of GCF collected from periodontitis patients was 3.72 fold higher than that in an equal volume of GCF collected from healthy individuals. ELISA analysis showed that the level of interukin-6 (IL-6), IL-8, metalloproteinases 2 (MMP-2), MMP-9, tumor necrosis factor-alpha (TNF-α), azurocidin, and odontogenic ameloblast-associated protein (ODAM) were higher in the GCF samples from the periodontitis patients than in those from the healthy individuals. However, the level of IL-6 and TNF-α were relatively low (> 5 pg/ml). The prostaglandin E2 (PGE2) levels were not significantly different between the two GCF samples. Conclusion: These results indicate that IL-8, MMP-2, MMP-9, azurocidin, and ODAM are potentially useful diagnostic biomarkers for periodontitis; combining multiple biomarkers will improve the diagnostic accuracy of periodontitis.