• Journal of Periodontal and Implant Science
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• v.50 no.1
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• pp.56-66
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• 2020

Purpose: A stability-measuring device that utilizes damping capacity analysis (DCA) has recently been introduced in the field of dental implantology. This study aimed to evaluate the sensitivity and reliability of this device by measuring the implant stability of ex vivo samples in comparison with a resonance frequency analysis (RFA) device. Methods: Six implant beds were prepared in porcine ribs using 3 different drilling protocols to simulate various implant stability conditions. Thirty-six pork ribs and 216 bone-level implants measuring 10 mm in height were used. The implant beds were prepared using 1 of the following 3 drilling protocols: 10-mm drilling depth with a 3.5-mm-diameter twist drill, 5-mm drilling depth with a 4.0-mm-diameter twist drill, and 10-mm drilling depth with a 4.0-mm-diameter twist drill. The first 108 implants were external-connection implants 4.0 mm in diameter, while the other 108 implants were internal-connection implants 4.3 mm in diameter. The peak insertion torque (PIT) during implant placement, the stability values obtained with DCA and RFA devices after implant placement, and the peak removal torque (PRT) during implant removal were measured. Results: The intraclass correlation coefficients (ICCs) of the implant stability quotient (ISQ) results obtained using the RFA device at the medial, distal, ventral, and dorsal points were 0.997, 0.994, 0.994, and 0.998, respectively. The ICCs of the implant stability test (IST) results obtained using the DCA device at the corresponding locations were 0.972, 0.975, 0.974, and 0.976, respectively. Logarithmic relationships between PIT and IST, PIT and ISQ, PRT and IST, and PRT and ISQ were observed. The mean absolute difference between the ISQ and IST values on a Bland-Altman plot was -6.76 (-25.05 to 11.53, P<0.05). Conclusions: Within the limits of ex vivo studies, measurements made using the RFA and DCA devices were found to be correlated under a variety of stability conditions.

• Journal of Oral Medicine and Pain
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• v.34 no.2
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• pp.153-167
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• 2009

The present study was performed to observe the effect of phytoncide on oral normal microflora and the inhibitory effect of the surviving resident oral bacteria on Pr. intermedia. In this study, saliva from each of 20 healthy subjects was treated with 1% phytoncide from Japanese Hinoki (Chamaecyparis obtusa Sieb. et Zucc.). Surviving salivary bacteria were isolated on blood agar plates and identified by 16S rDNA sequencing. In order to select inhibitory isolates against Pr. intermedia, the isolates from the phytoncide-treated saliva were cultured with Pr. intermedia. The results were as follows: 1. Among the 200 surviving resident oral bacterium, 148(74.0%) bacterium inhibit the growth of Pr. intermedia on blood agar plates. 2. The 200 surviving resident oral bacterium were 109 Streptococcus salivarius(54.5%), 25 Streptococcus sanguinis(12.5%), 15 Streptococcus mitis(7.5%). 3. Among the 148 bacteria which inhibit Pr. intermedia, Streptococcus salivarius was 85.3%(93/109), Streptococcus sanguinis was 64.0%.(16/25), Streptococcus mitis was 54.3%(8/15), Streptococcus parasanguinis was 66.7%(6/9), and Streptococcus Alactolyticus was 100%(8/8). Taken together, among the surviving resident oral bacterium, Streptococcus salivarius, Streptococcus sanguinis, Streptococcus mitis were mainly observed to inhibit Pr. intermedia. and they may exert an additional inhibitory activity against the periodontopathic bacterium. Therefore, phytoncide can be used for preventing and ceasing the progress of periodontal disease and halitosis, and thus is expect to promote oral health.

• Journal of Oral Medicine and Pain
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• v.34 no.2
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• pp.123-132
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• 2009

Purpose : To investigate the actual conditions of diagnosis and treatment of oral medicine inpatient with systemic disease. Methods : A total of 54 oral medicine subjects, inpatient due to systemic disease for diagnosis and treatment of oral disease was requested to answer the medical history and dental treatment record. Results : The ratio of gender is composed of male 44% and female 56%, the distribution of age is the order of the 50-59 group 37%, the 60-69 group 26%, the 40-49 group 22%. Systemic disease is composed of Endocrine, nutritional and metabolic diseases 36%, Diseases of the circulatory system 36%, Diseases of the nervous system 10%. Chief complain of oral disease is composed of routine check for oral health 26%, craniomandibular disorders 18%, soft tissue problem 18%. Oral disease is composed of Diseases of salivary glands 32%, Gingivitis and periodontal diseases 23%, Dentofacial anomalies 16% Conclusion : These findings indicate that oral medicine inpatient due to the systemic disease is significantly correlated to the oral disease. The patients of oral disease interrelationship between inpatient and outpatient of systemic disease should be validated by future research.

• Journal of Korean society of Dental Hygiene
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• v.21 no.6
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• pp.695-701
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• 2021

Objectives: This study aimed to determine the effect of COVID-19-induced household economic deterioration on gingival pain and bleeding. Methods: Data from the 16th Adolescent Health Behavior Survey 2020 were used. A total of 57,925 adolescents were included in this cross-sectional study. We evaluated the worsening of the COVID-19-induced household economic situation, gingival pain, and bleeding. All surveys were assessed in a subjective non-face-to-face online interview. Data were analyzed using descriptive statistics, chi-squared tests, and logistic regression. Results: The overall prevalence of gingival pain and bleeding symptoms in the study population was 19.2%. People with COVID-19 were more likely to suffer from gingival pain and gingival bleeding than those who did not have economic deterioration due to COVID-19. There was no economic deterioration due to COVID-19 (aOR=1.048, 95% CI=1.034-1.227) and worsened very much (aOR=1.358, 95% CI=1.164-1.585). Conclusions: There were more cases of gingival pain and gingival bleeding, which are early symptoms of periodontal disease, in patients with COVID-19 compared to cases without deterioration of the household economic situation due to COVID-19. It is necessary to measure and study gingival bleeding objectively rather than relying on self-reports.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.2
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• pp.206-216
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• 2022

This study aimed to investigate the frequency of dental visits after coronavirus disease 2019 (COVID-19) in children and adolescents in comparison to that of adults. The data on the number of dental visits on the basis of different classification and treatment codes for all the age groups were provided by the Health Insurance Review and Assessment Service from January 2017 to December 2020. To reduce the impact of the population change, dental visits per 1000 people was used. After the start of the pandemic, dental visits per 1000 people decreased in all age groups when analyzed for the diseases of pulp and periapical tissues classification code and dental visits per 1000 people decreased over 5 years age groups when analyzed for the pulp treatment code. Regarding the restorative treatment code, visits in the 0 - 19 years age group decreased after the pandemic. Based on the comparison of the number of confirmed COVID-19 cases to that of monthly dental visits by treatment codes, the change rate of pulp and restorative treatments gradually decreased after the waves of the pandemic in February and August 2020 in Korea. Furthermore, dental visits per 1000 people for gingivitis and periodontal disease classification code increased after the pandemic in all age groups. The rate of decrease in dental visits per 1000 people for restorative treatments in children and adolescents was higher than that in adults. The rate of decrease in the number of dental visits for multi-visit pulp treatments showed a rapid decrease as compared to that of 1-visit pulp treatments after the pandemic. This study identified changes in the number of dental visits of children and adolescents after COVID-19 transmission in comparison to that observed in adults.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.150-157
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• 2014

The aim of this study was to suggest a convenient method of monitoring the gingival state through plaque detection. Quantitative Light-Induced Fluorescence-Digital (QLF-D), which can assess mature plaque, can be used to assess the oral hygiene status of individuals and to establish an adequate intervention plans for them. The subjects of the study participated in the clinical training at Department of Dental Hygiene, N University. The subjects completed questionnaires on general characteristics and oral hygiene methods. Then, photographs of maxillary and mandibular anterior teeth of the subjects were taken using the QLF-D. After the oral examinations, gingival state was recorded according to the $L{\ddot{o}}e$ & Silness's Gingival Index (GI). In addition, a plaque control record was calculated in percentage using disclosing agent. The analysis of the relation between the plaque control record and the QLF-D scores showed positive correlation (r=0.638, p<0.001), and the analysis of the relation between the QLF-D scores and the gingival bleeding index scores also showed positive correlation (r=0.562, p<0.001). Besides, the study classified the participants into healthy gingiva group and the gingivitis group according to the classification criteria of GI, and when the difference of QLF-D scores between the groups was analyzed, the QLF-D scores were statistically significantly higher (t=-2.785, p=0.007) in the gingivitis group ($1.71{\pm}1.545$) than the healthy gingiva group ($0.74{\pm}1.290$). When the differences in mean values of the QLF-D scores were analyzed against and the gingival bleeding index scores, the QLF-D scores of 0 and 1 belonged to the category of normal gingival state while the QLF-D scores of 2, 3 and 4 belonged to the category of gingivitis state. Therefore, it is deemed that the red fluorescence detected by the QLF-D from the mature supragingival plaque can be used for monitoring the state of gingivitis.

• Journal of dental hygiene science
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• v.18 no.6
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• pp.340-348
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• 2018

The purpose of this study was to examine the perceptions, precedent tasks, positive and negative effects, and expandable professional tasks regarding the inclusion of dental hygienists (DHs) in the category of medical personnel. This study involved a survey of 259 DHs and 128 dentists. The findings were as follows: 94.2% of DHs and 46.9% of dentists were aware of inclusion in the category of medical personnel; 95.0% of DHs and 64.1% of dentists supported the idea; and 84.9% of DHs and 51.6% of dentists recognized its legitimacy. As for precedent tasks for inclusion in the category of medical personnel, both DHs and dentists scored high points in professional consciousness in the area of occupation. Both DHs and dentists scored the highest points in the quality management of DH education and the lowest points in the unification of school systems in the area of institution. In the area of society, DHs scored high points in the persuasion of the central government, whereas dentists scored high points in collaboration among concerned organizations. Regarding the positive effects of inclusion in the category of medical personnel, both DHs and dentists scored the highest points in the expanded perception of DHs. As for its negative effects, DHs scored high points in the aggravation of salary increase, whereas dentists scored high points in the aggravation of salary increase. Regarding expandable professional tasks after the inclusion of DHs in the category of medical personnel, the management of independent periodontal care programs recorded the highest percentage both in DHs and dentists. These findings highlight the need for adequate discussions about the meanings of the inclusion of DHs in the category of medical personnel and will hopefully contribute to the rational adjustment and legalization of DHs' works with regard to their inclusion in the category of medical personnel.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.324-332
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• 2009

The purpose of this study was to investigate the effect of rigidity of post core systems on stress distribution by the theoretical technique, finite element stress-analysis method. Three-dimensional finite element models simulating an endodontically treated maxillary central incisor restored with a zirconia ceramic crown were prepared and 1.5 mm ferrule height was provided. Each model contained cortical bone, trabecular bone, periodontal ligament, 4 mm apical root canal filling, and post-and-core. Six combinations of three parallel type post (zirconia ceramic, glass fiber, and stainless steel) and two core (Paracore and Tetric ceram) materials were evaluated, respectively. A 50 N static occlusal load was applied to the palatal surface of the crown with a $60^{\circ}$angle to the long axis of the tooth. The differences in stress transfer characteristics of the models were analyzed. von Mises stresses were chosen for presentation of results and maximum displacement and hydrostatic pressure were also calculated. An increase of the elastic modulus of the post material increased the stress, but shifted the maximum stress location from the dentin surface to the post material. Buccal side of cervical region (junction of core and crown) of the glass fiber post restored tooth was subjected to the highest stress concentration. Maximum von Mises stress in the remaining radicular tooth structure for low elastic modulus resin core (29.21 MPa) was slightly higher than that for high elastic modulus resin core (29.14 MPa) in case of glass fiber post. Maximum displacement of glass fiber post restored tooth was higher than that of zirconia ceramic or stainless steel post restored tooth.