Effects of a blended design of closed-book and open-book examinations on dental students' anxiety and performance.

BACKGROUND: While closed-book examinations (CBEs) have traditionally been implemented in dental education, open-book examinations (OBEs) are being introduced for the purpose of acquiring higher levels of knowledge and promoting long-term memory. This study examines whether it is effective to use a blended assessment of CBEs and OBEs for dental students to reduce test anxiety and enhance academic performance. METHODS: Using a quasi-experimental research method, a blended assessment that combined CBEs in class and OBEs online was designed for a dental course. In 2020, when the pandemic was at its peak, student assessment was ineffective, and the 2020 cohort was omitted for our study; instead, two cohorts of predoctoral dental students (N = 178) enrolled in Restorative Dentistry in the spring semesters of 2019 and 2021 were included in the study. These students were informed about the experimental design, and they provided written consent for data collection, thereby voluntarily participating in the survey. Their self-perceived responses to open-ended survey questions on assessment methods were qualitatively analyzed. RESULTS: There was no significant difference in test anxiety between the CBEs and OBEs at the p-values of 0.001 in all items. Traditional and blended assessment showed a similar trend of lower scores in midterm exams compared to higher scores in final exams, thus discriminating against students' performances. In particular, a low-achieving group was better predicted by a blended assessment. An analysis of the students' self-perceived responses produced highly topical themes, including exam burden, learning effects, and fairness issues. CONCLUSIONS: This study confirmed the feasibility of blended assessment that can be implemented in online and in-person educational environments. Moreover, it can be used as the groundwork to develop new models of assessment in dental education.

Role of Zinc-Doped Bioactive Glass Encapsulated with Microspherical Gelatin in Localized Supplementation for Tissue Regeneration: A Contemporary Review.

Gelatin, a natural polymer, provides excellent tissue compatibility for use in tissue rehabilitation. Bioactive glasses (BAG) offer superior capacity in stimulating a bioactive response but show high variability in uptake and solubility. To tackle these drawbacks, a combination of gelatin with BAG is proposed to form composites, which then offer a synergistic response. The cross-linked gelatin structure's mechanical properties are enhanced by the incorporation of the inorganic BAG, and the rate of BAG ionic supplementation responsible for bioactivity and regenerative potential is better controlled by a protective gelatin layer. Several studies have demonstrated the cellular benefits of these composites in different forms of functional modification such as doping with zinc or incorporation of zinc such as ions directly into the BAG matrix. This review presents a comprehensive perspective on the individual characteristics of BAG and gelatin, including the synthesis and mechanism of action. Further, adaptation of the composite into various applications for bone tissue engineering is discussed and future challenges are highlighted.

Surface Characterization, Biocompatibility and Antifungal Efficacy of a Denture-Lining Material Containing Cnidium officinale Extracts.

Herein, we investigated the surface characterization and biocompatibility of a denture-lining material containing Cnidium officinale extracts and its antifungal efficacy against Candida albicans. To achieve this, a denture-lining material containing various concentrations of C. officinale extract and a control group without C. officinale extract were prepared. The surface characterization and biocompatibility of the samples were investigated. In addition, the antifungal efficacy of the samples on C. albicans was investigated using spectrophotometric growth and a LIVE/DEAD assay. The results revealed that there was no significant difference between the biocompatibility of the experimental and control groups (p > 0.05). However, there was a significant difference between the antifungal efficiency of the denture material on C. albicans and that of the control group (p < 0.05), which was confirmed by the LIVE/DEAD assay. These results indicate the promising potential of the C. officinale extract-containing denture-lining material as an antifungal dental material.

Korean National Oral Health Survey Data on the Symmetry of Primary Dentition Surface Caries.

OBJECTIVES: This study evaluated the intraoral symmetry of dental caries in primary teeth as part of a study of caries patterns in primary dentition. STUDY DESIGN: The data for 4,800 5-year-old and 4,379 8-year-old children in this study were from the 2012 Korean national oral health survey. Pearson correlation coefficients of the decayed and filled surface (dfs) values ranged from 0.436 (lower primary canines) to 0.835 (upper primary central incisors) for the right and left primary teeth and from 0.084 (right primary central incisor) to 0.457 (left primary second molar) for the upper and lower primary dentition (P< 0.01). RESULTS: The upper and lower dfs values differed significantly (P< 0.05) when the right and left primary second molars were excluded. The left or right primary data without caries ranged from 56.4% (lower of first and second primary molars) to 99.7% (lower primary central incisors). The bilateral caries among cases with one or more in the right or left primary teeth ranged from 25.0% (lower lateral primary incisor) to 72.7% (upper primary central incisors). CONCLUSIONS: These results suggested that dental caries in primary teeth show bilateral symmetry and differences in the degree of symmetry according to the teeth set or surface set of the homologous teeth.

Caries Prevalence in Korean Children and Adolescents from 2000 to 2012.

OBJECTIVES: National oral health data is required to assess a population's oral health needs, monitor oral health, plan effective intervention community programs and health policies, and evaluate progress toward health objectives. The study aimed to estimate the prevalence, severity, and inequality in dental caries distribution among Korean young people. STUDY DESIGN: Trained, calibrated examiners at the Korea Ministry of Health & Welfare conducted epidemiological surveys in 2000, 2006, and 2012 during which dental caries were assessed according to World Health Organization (WHO) diagnostic criteria. Decayed, missing, and filled surface and tooth (DMFS/DMFT) indices were estimated. RESULTS: DMFT indices decreased in all regions between 2000 and 2012, with values of 3.3, 2.2, and 1.8 for 12-year-old children in 2000, 2006, and 2012, respectively. The prevalence of caries was higher among female versus male subjects and in rural versus urban areas. CONCLUSIONS: Despite the observed decrease in caries experience indicators in Korea, the caries prevalence remains considerably higher than that in European countries and than the targets set by WHO within the Health21 policy framework. Therefore, Korea apparently retains further potential for caries reduction. Community-based oral disease prevention programs are urgently needed to promote oral health.

Colloidal interactions of inorganic nanoparticles grafted with zwitterionic polymer brushes and gels by surface-mediated seeded polymerization.

A robust and straightforward approach is introduced to synthesize inorganic nanoparticles chemically grafted with a zwitterionic poly(2-methacryroyloxyethylphosphorylcholine) (PMPC) thin layers. The synthesis method is based on the surface-mediated seeded polymerization. In order to observe how the polymer chain architectures affect colloidal interactions, the zinc oxide nanoparticles are grafted with linear brushes and with a thin hydrogel layer, respectively. The thickness of PMPC shell layers spans a few nanometers. The studies on suspension rheology for the nanoparticles show that the nanoparticles with PMPC brushes show the stronger repulsive force than those with the PMPC gel shell due to the entropic stabilization. When the shear force is applied to the Pickering emulsion produced by assembly of the nanoparticles, it is noticeable that the presence of PMPC brushes on the particles rather enhances the drop-to-drop attraction, which presumably stems from the entanglement of polymer chains between the contacted interfacial planes of the emulsion droplets during shearing.

Investigation of the impact of dental fear on Child Oral Health Impact Profile scores.

BACKGROUND: The Child Oral Health Impact Profile (COHIP) is a measure of oral health-related quality of life (OHRQoL) in children and adolescents. This study examined the impact of dental fear on the OHRQoL by comparing the COHIP scores of children with and without dental fear. METHODS: The OHRQoL in children and adolescents was measured using the Korean version of the COHIP. In total, 102 students (49 boys and 53 girls) filled in a questionnaire designed to evaluate dental fear and the OHRQoL in 2012 and 2014. RESULTS: In 2012, the group without dental fear showed higher COHIP scores than the group with dental fear; the difference between the two groups was statistically significant. In 2014, the same pattern was observed, but the difference was non-significant for all COHIP items other than those pertaining to social-emotional well-being. Comparison of COHIP scores according to changes in fear showed that the group with continuous dental fear showed significantly lower overall COHIP, negative COHIP, and low social-emotional wellbeing scores, than the group without continuous fear in 2012 and 2014. CONCLUSION: We expected children with dental fear to have poor oral health, affecting their OHRQoL; however, dental fear did not affect the OHRQoL.

Verification of the Korean Version of the Dental Fear Survey.

BACKGROUND: Although studies on dental fear in relation to sex and age have been conducted, there have been few nationwide studies particularly on the youth sector. In addition, no validity and reliability verifications have been implemented for new research groups on the Korean version of the Dental Fear Survey (K-DFS). Therefore, this study aimed to apply the K-DFS developed in a previous study on Korean youth to draw conclusions on dental fear among the youth. METHODS: This study used the K-DFS, a Korean translation of Kleinknecht's Dental Fear Survey for elementary school, middle school, and high school students. This study selected 2,161 young people of various ages as participants and increased the validity of the research results by expanding nationwide the scope of the study area. RESULTS: Differences in fear levels according to sex were higher in boys fear behavior scores than in girls' regarding dental treatment (P < 0.05). Students with dental fear had higher scores on items associated with dental treatment and fear of dental stimuli compared with students without dental fear (P < 0.05). Differences were observed among the three groups (P < 0.05). However, the results of logistic regression analysis showed no statistically significant differences for dental visits based on sex, grade, and other subcomponents (P > 0.05). CONCLUSION: By verifying the validity of the newly developed K-DFS, this research confirmed its utility as a dental fear questionnaire. Therefore, there can be no objection that the grounds for criticism have been established according to conventional wisdom. In the future, however, developing and studying the limits of K-DFS that overcome the factors of dental fear, especially pain, will help reduce dental fear in adolescents.

New treatment method for pain and reduction of local anesthesia use in deep caries.

Chemo-mechanical caries removal methods are known to be more effective compared with conventional methods in pain reduction. Carie-care™, a chemo-mechanical caries removal agent, was introduced in 2010 but a systematic review of its efficacy has not yet been performed. The purpose of this study was to investigate the effectiveness of Carie-care™ on the outcomes of treatment of caries in children and adolescents. The primary outcome was pain while the secondary outcomes included complete caries removal (CCR), time, need for local anesthesia and behavioral response changes. A Comprehensive literature search was performed in PubMed, EMBASE, and the Cochrane Library up to 30 September 2018. The following keywords were used in the search: 'chemo-mechanical caries removal agent', 'dental caries', 'Carie-care', 'chemo-mechanical caries removal', 'chemo-mechanical caries excavation', other related keywords, and their combinations. From 942 studies identified, 16 were analyzed. Finally, 4 studies met the eligibility criteria and 260 teeth in 120 children and adolescents were included in this review. This review showed that Carie-care™ reduces pain during caries treatment but requires a longer time for effective treatment than conventional methods. Local anesthesia was not required in the Chemo-mechanical caries removal (CMCR) group. In addition, dental anxiety decreased compared to the control group, and co-operation was more positive. Therefore, it may be a useful alternative to conventional methods in children and adolescents, but further verification through additional studies is needed.

Do Dental Students' Personality Types and Group Dynamics Affect Their Performance in Problem-Based Learning?

The aim of this study was to determine whether the personality types of dental students and their group dynamics were linked to their problem-based learning (PBL) performance. The Myers-Briggs Type Indicator (MBTI) instrument was used with 263 dental students enrolled in Seoul National University School of Dentistry from 2011 to 2013; the students had participated in PBL in their first year. A four-session PBL setting was designed to analyze how individual personality types and the diversity of their small groups were associated with PBL performance. Overall, the results showed that the personality type of PBL performance that was the most prominent was Judging. As a group became more diverse with its different constituent personality characteristics, there was a tendency for the group to be higher ranked in terms of PBL performance. In particular, the overperforming group was clustered around three major profiles: Extraverted Intuitive Thinking Judging (ENTJ), Introverted Sensing Thinking Judging (ISTJ), and Extraverted Sensing Thinking Judging (ESTJ). Personality analysis would be beneficial for dental faculty members in order for them to understand the extent to which cooperative learning would work smoothly, especially when considering group personalities.

The relationship between subjective oral health and dental fear in Korean adolescents.

BACKGROUND: This study is aimed to evaluate the level of fear and to reduce the overall fear, thereby enabling patients to receive treatment via timely visits. METHODS: In a survey conducted by 460 South Korean middle school students, we used 453 data that faithfully responded to the survey. Multiple regression analysis was conducted to investigate the factors influencing subjective oral health and dental fear. The significance level used for statistical significance was α = 0.05. RESULTS: The level of fear was higher for upper grade, female students. The factors affecting dental fear were higher for gingival bleeding and dental pain. Regarding factors for dental fear affecting subjective oral health, lower fear of puncture needle and tooth removal tool resulted in higher subjective oral health. CONCLUSION: The study found that adolescents had higher fear of dental care when they had gingival bleeding and tooth pain. Gingival bleeding is a symptom of early gingival disease and dental pain is likely due to advanced dental caries. These results suggested that it is necessary to have a program to reduce dental fear and anxiety as well as a program to prevent dental diseases through regular periodic screening and education.

Three-dimensional measurement of periodontal surface area for quantifying inflammatory burden.

PURPOSE: Measurement of the root surface area (RSA) is important in periodontal treatment and for the evaluation of periodontal disease as a risk factor for systemic disease. The aim of this study was to measure the RSA at 6 mm below the cementoenamel junction (CEJ) using the Mimics software (Materialise, Leuven, Belgium). METHODS: We obtained cone-beam computed tomography (CBCT) data from 33 patients who had visited the Department of Oral and Maxillofacial Radiology of Dankook University Dental Hospital. The patients comprised 17 men and 16 women aged from 20 to 35 years, with a mean age of 24.4 years. Only morphologically intact teeth were included in our data. Because the third molars of the maxilla and mandible have a high deformation rate and were absent in some participants, they were not included in our research material. RESULTS: The CBCT data were reconstructed into 3-dimensional (3D) teeth models using the Mimics software, and the RSA at 6 mm below the CEJ was separated and measured using 3-Matic (Materialise). In total, 924 3D teeth models were created, and the area at 6 mm below the CEJ could be isolated in all the models. The area at 6 mm below the CEJ was measured in all teeth from the 33 patients and compared based on sex and position (maxilla vs. mandible). CONCLUSIONS: In this study, we demonstrated that it was feasible to generate 3D data and to evaluate RSA values using CBCT and the Mimics software. These results provide deeper insights into the relationship between periodontal inflammatory burden and systemic diseases.

Cytotoxic effects of one-step self-etching adhesives on an odontoblast cell line.

The aim of this study was to evaluate the cytotoxic effects of one-step self-etching adhesives. Cells from an immortalized mouse odontoblast cell line (MDPC-23) were cultured with six different dental adhesive systems (diluted to concentrations of 0.5% for 4 h): Adper Easy Bond (EB), Xeno V (XV), iBond (IB), AdheSE One (AO), Clearfil SE primer (CS), and Adper Single Bond 2 (SB). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and flow cytometric apoptosis assays were used to evaluate cell viability and the rate of apoptosis. The odontoblasts were also examined under a scanning electron microscope. While all of the cultures with adhesives showed reduced viability, the viabilities in the IB and SB groups were not significantly different from the control group. Although increased apoptosis rates were observed in all of the cultures with adhesives, the rate in the SB group was not significantly different from the rate in the control. The control group showed the lowest apoptosis rate followed by the SB, AO, IB, EB, XV, and CS groups. When examined under a scanning electron microscope, control odontoblasts and the SB group exhibited relatively large cytoplasmic extensions. In contrast, in the EB and CS groups, fewer fibroblasts remained adhered to the plate surface. Cytoplasmic membrane shrinkage and cell-free areas with residual membrane fragments from dead cells were observed. In conclusion, all cultures with one-step self-etching adhesives showed increased apoptotic activity. SB, an etch-and-rinse adhesive, was comparable to the control group, and CS and EB showed the lowest odontoblast viabilities according to the MTT assay.

Developmental procedures for the clinical practice guidelines for conscious sedation in dentistry for the Korean Academy of Dental Sciences.

BACKGROUND: Evidence-based clinical practice guidelines (CPGs) are defined as "statements that are scientifically reviewed about evidence and systematically developed to assist in the doctors' and patients' decision making in certain clinical situations." This recommendation aims to promote good clinical practice for the provision of safe and effective practices of conscious sedation in dentistry. METHODS: The development of this clinical practice guideline was conducted by performing a systematic search of the literature for evidence-based CPGs. Existing guidelines, relevant systematic reviews, policy documents, legislation, or other recommendations were reviewed and appraised. To supplement this information, key questions were formulated by the Guideline Development Group and used as the basis for designing systematic literature search strategies to identify literature that may address these questions. Guideline documents were evaluated through a review of domestic and international databases for the development of a renewing of existing conscious sedation guidelines for dentistry. Clinical practice guidelines were critically appraised for their methodologies using Appraisal of guidelines for research and evaluation (AGREE) II. RESULTS: A total of 12 existing CPGs were included and 13 recommendations were made in a range of general, adult, and pediatric areas. CONCLUSION: The clinical practice guidelines for conscious sedation will be reviewed in 5 years' time for further updates to reflect significant changes in the field.

Study on the trends in Korean clinical practice guidelines development.

BACKGROUND: The definition of evidence-based clinical practice guidelines (CPGs) is "statements that are systematically developed to assist in the doctors' and patients' decision-making in certain situations." This study aims to establish the concept of evidence-based CPGs and investigate the development status to seek measures to apply evidence-based methods to CPG development for dental sedation in Korea. METHODS: The study conducted systematic searching methods based on evidence-based CPGs. Articles published between 1995 to 2015 were searched on a Korean database and the international database PubMed. The search was based on keywords related to four subjects (dentistry, clinical practice, guideline, recommendation). Two authors independently reviewed the searched articles to determine their analysis inclusion and the convergence stages, and to arrive at a conclusion through discussion. RESULTS: A total of 65 Korean CPGs were included. There were 51 medical guidelines, of which seven were dental and seven were Oriental medicine. CONCLUSIONS: As a basic direction for the development of evidence-based CPGs, this work suggests the following: increased awareness; consensus on the need to supply evidence-based development methods; education, computerization, and systematic observation of evidence-based CPG development methods; continuous research development and distribution of CPGs; and creation of a database for Korean clinical dentistry practice outcomes.

Chamaecyparis obtusa Suppresses Virulence Genes in Streptococcus mutans.

Chamaecyparis obtusa (C. obtusa) is known to have antimicrobial effects and has been used as a medicinal plant and in forest bathing. This study aimed to evaluate the anticariogenic activity of essential oil of C. obtusa on Streptococcus mutans, which is one of the most important bacterial causes of dental caries and dental biofilm formation. Essential oil from C. obtusa was extracted, and its effect on bacterial growth, acid production, and biofilm formation was evaluated. C. obtusa essential oil exhibited concentration-dependent inhibition of bacterial growth over 0.025 mg/mL, with 99% inhibition at a concentration of 0.2 mg/mL. The bacterial biofilm formation and acid production were also significantly inhibited at the concentration greater than 0.025 mg/mL. The result of LIVE/DEAD® BacLight™ Bacterial Viability Kit showed a concentration-dependent bactericidal effect on S. mutans and almost all bacteria were dead over 0.8 mg/mL. Real-time PCR analysis showed that gene expression of some virulence factors such as brpA, gbpB, gtfC, and gtfD was also inhibited. In GC and GC-MS analysis, the major components were found to be α-terpinene (40.60%), bornyl acetate (12.45%), α-pinene (11.38%), ß-pinene (7.22%), ß-phellandrene (3.45%), and α-terpinolene (3.40%). These results show that C. obtusa essential oil has anticariogenic effect on S. mutans.

Dental fear & anxiety and dental pain in children and adolescents; a systemic review.

BACKGROUND: There are few previous studies investigating the relationship of dental fear and anxiety (DFA) with dental pain among children and adolescents. To address this issue, we examined the literature published between November 1873 and May 2015 to evaluate the prevalence of DFA and dental pain among children and adolescents, and their relationships with age and sex. METHODS: We performed a broad search of the PubMed database using 3 combinations of the search terms dental fear, anxiety, and dental pain and prevalence. A large proportion of the identified articles could not be used for the review due to inadequate end points or measures, or because of poor study design. Thirty-two papers of acceptable quality were identified and reviewed. RESULTS: We found that the prevalence of DFA was estimated to be 10%, with a decrease in prevalence with age. It was more frequently seen in girls, and was related to dental pain. CONCLUSIONS: We concluded that dental fear, anxiety, and pain are common, and several psychological factors are associated with their development. In order to better understand these relationships, further clinical evaluations and studies are required.

Reliability and validity of the Korean version of the Dental Fear Survey.

BACKGROUND: Many people experience varying levels of discomfort when confronted with the prospect of dental treatment. Dental treatment can be a traumatic experience, especially for children and adolescents with dental anxiety. In this age group, dental fear causes a significant problem in dental management and has been related to severe dental caries and dental pain. The Dental Fear Survey ( DFS ) is the most widely used measure of dental fear. This study was undertaken to develop the Korean version of the DFS ( K-DFS ) and test its reliability and validity. METHODS: The K-DFS, which uses projective techniques to measure children's and adolescents' dental fear, was developed. The DFS was translated into Korean and participants were selected via convenience sampling. Reliability and validity were tested using data from a sample of 813 middle school students in Gyeonggi Province, selected from the Self questionnaire survey. The K-DFS was administered twice to 102 adolescents aged 12-15 years. RESULTS: The K-DFS had high internal consistency reliability (99.1%) but low test-retest reliability. CONCLUSIONS: The results indicate that the Korean versions of the DFS have good internal consistency reliabilities and test-retest validities. However, we need to further examine the test-retest reliability of the K-DFS and replicate the current study in different samples covering various age groups.

Use of three-dimensional computed tomography images in dental care of children and adolescents in Korea.

Advances in computed tomography (CT) technology - from traditional CT to cone beam (CB) CT - have benefitted both the dentists and their young patients. We therefore wanted to determine the prevalence of CBCT use in pediatric dentistry in Korea. Our first approach was to conduct an institutional survey to evaluate the use of CBCT for diagnosing and evaluating dental problems in pediatric patients. Our second approach was to review any articles published during 2002-2011 in the Journal of the Korean Academy of Pediatric Dentistry that described clinical use of CBCT. The journal articles surveyed indicated that there were three areas in which CBCT was most useful. The most prevalent use was for diagnosis and monitoring of the growth of cystomas and other tumors in the mouth. The second most common use of CBCT was localization of impacted teeth and evaluation of their relations with adjacent teeth. The third use was to observe supernumerary teeth and evaluate their relations with the roots of adjacent teeth. Compared with traditional CT, CBCT has shorter acquisition times and causes less radiation exposure to the patient. There are fewer side effects with CBCT because its accuracy allows minimally invasive treatment for such problems as impacted and supernumerary teeth.

Restoration of strip crown with a resin-bonded composite cement in early childhood caries.

Background. Early childhood caries is a widely prevalent disease throughout the world. It is necessary to treat this condition in early childhood; however, child behavior management may be particularly challenging during treatment. To overcome this challenge, we used Carigel to remove caries and RelyX Unicem resin cement for strip crown restoration. It not only has the desired aesthetic effect but is also more effective for primary teeth, which are used for a shorter period than permanent teeth are. Case Presentation. We report a case of three pediatric patients with early childhood caries, in whom caries was removed by using Carigel to avoid the risk of pulpal exposure associated with high-speed handpieces. Subsequently, aesthetic restoration was performed using strip crown with RelyX Unicem self-adhesive resin cement. Conclusion. RelyX Unicem has the following advantages: (1) not requiring have any special skills for the dentist for performing the procedure, (2) decreased occurrence of bubbles during injection of the cement, and (3) overall short duration of the procedure. Thus, it is appropriate for the treatment of pediatric patients whose behavior is difficult to manage. However, further studies are required in order to establish the use of RelyX Unicem as a stable restorative material in early childhood caries.