First crystal structure of the DUF2436 domain of virulence proteins from Porphyromonas gingivalis.

Porphyromonas gingivalis is a major pathogenic oral bacterium that is responsible for periodontal disease. It is linked to chronic periodontitis, gingivitis and aggressive periodontitis. P. gingivalis exerts its pathogenic effects through mechanisms such as immune evasion and tissue destruction, primarily by secreting various factors, including cysteine proteases such as gingipain K (Kgp), gingipain R (RgpA and RgpB) and PrtH (UniProtKB ID P46071). Virulence proteins comprise multiple domains, including the pro-peptide region, catalytic domain, K domain, R domain and DUF2436 domain. While there is a growing database of knowledge on virulence proteins and domains, there was no prior evidence or information regarding the structure and biological function of the well conserved DUF2436 domain. In this study, the DUF2436 domain of PrtH from P. gingivalis (PgDUF2436) was determined at 2.21 Šresolution, revealing a noncanonical ß-jelly-roll sandwich topology with two antiparallel ß-sheets and one short α-helix. Although the structure of PgDUF2436 was determined by the molecular-replacement method using an AlphaFold model structure as a template, there were significant differences in the positions of ß1 between the AlphaFold model and the experimentally determined PgDUF2436 structure. The Basic Local Alignment Search Tool sequence-similarity search program showed no sequentially similar proteins in the Protein Data Bank. However, DaliLite search results using structure-based alignment revealed that the PgDUF2436 structure has structural similarity Z-scores of 5.9-5.4 with the C-terminal domain of AlgF, the D4 domain of cytolysin, IglE and the extracellular domain structure of PepT2. This study has elucidated the structure of the DUF2436 domain for the first time and a comparative analysis with similar structures has been performed.

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.

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.

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.

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.

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.