Analysis of approved dental teaching projects in the teaching practice research program in 8 dental schools of Taiwan from 2018 to 2023.

Background/purpose: The teaching practice research program was initiated by Taiwan's Ministry of Education in 2018 to improve medical teaching quality. This study analyzed dental teaching projects conducted under this program from 2018 to 2023. Materials and methods: Data of submitted and approved medical (including dental) teaching projects from 2018 to 2023 were obtained from the annual reports released by the program committee. The annual passing rates were calculated by dividing the number of approved dental teaching projects by the total number of approved medical teaching projects in the category of medical and healthcare sciences in a particular year. The 24 approved dental teaching projects were reviewed, classified into different topics in the dental field, and then reported. Results: There were 24 approved dental teaching projects out of a total of 822 approved medical teaching projects from 2018 to 2023. The annual passing rates increased gradually from 2018 (1.4 %) to 2022 (3.9 %) and 2023 (3.8 %) with an overall mean passing rate of 2.9 % over a period of 6 years. Of the 24 approved dental teaching projects, digital dentistry was the most common teaching research topic (9 projects), followed by new teaching models (7 projects), 3D technology (3 projects), endodontics (3 projects), dental histology (one project), and evidence-based method (one project). Conclusion: Digital dentistry and new teaching models were the two predominant dental teaching research topics, suggesting that both are the modern trends in the dental education. However, the dental teaching research projects are still very limited in 8 Taiwanese dental schools.

A registry-based study of tooth-colored restorative materials for decayed teeth in Taiwan.

Background/purpose: As esthetic demands with direct restorations, tooth-colored materials were used to replace amalgam filling gradually. However, little is known about the tooth-colored restorative materials for decayed teeth in Taiwan. In this study, the use of composite resin, glass ionomer cement, and compomer was analyzed by National Health Insurance Research Database (NHIRD). Materials and methods: A retrospective study was conducted to analyze the registered database compiled by Taiwanese NHIRD from 1997 to 2013. The results were further to analyze the application of tooth-colored restorative materials by sex and age. In addition, time trends of dental visits for each tooth-colored restorative material were also investigated. Results: The average annual composite resin filling (CRF) ratio was 18.41% of nationwide population in Taiwan. The prevalence of CRF stratified by sex and age was significantly increased from 1997 to 2013 (P for trend <0.0001). The time trends of dental visits for CRF were significantly increased (P for trend <0.0001). The average annual glass ionomer cement filling (GICF) ratio was 1.79% of Taiwanese population. The prevalence of GICF stratified by sex and age was demonstrated a decreased pattern (P for trend <0.0001). The time trends of dental visits for GICF were significantly decreased (P for trend <0.0001). The average annual compomer filling ratio was 0.57% of whole population in Taiwan. Conclusion: Form the results of this registry-based study, a significant increased trend of CRF for decayed teeth was observed in Taiwanese population during past 17 years.

Decreased trends of using dental amalgam filling for decayed teeth in Taiwan from 1997 to 2013.

Background/purpose: Mercury within dental amalgam has been criticized for the potential toxicity and environmental hazard. Phasing down the use of dental amalgam is the transition for amalgam free dentistry. However, little is known about dental amalgam filling (AMF) in Taiwan. In this study, time trends of AMF were measured by using National Health Insurance Research Database (NHIRD). Materials and methods: A retrospective study was conducted to analyze the AMF data in registered database compiled by Taiwanese NHIRD from 1997 to 2013. The AMF data were further analyzed according to sex, age, and geographic location, respectively. Time trends of dental visits for AMF and medical expenses for AMF were also evaluated. Results: The average annual AMF ratio was 8.965% of nationwide population in Taiwan. The prevalence of AMF was significantly decreased both in male and female from 1997 to 2013 (P for trend <0.0001). The decreased pattern of AMF was found by the age stratification (P for trend <0.0001). The significant fall of AMF was also displayed in six districts (P for trend <0.0001). The number of dental visits were ranged from 821,749 in 1997 to 1,313,734 in 2013. However, time trends of dental visits for AMF were significantly decreased (P for trend <0.0001). The medical expenses for AMF were simultaneous significantly decreased from 1997 to 2013 (P for trend <0.0001). Conclusion: Form the results of this nationwide population-based database, a significant decrease of AMF in Taiwan was observed during past 17 years.

Rutin alleviates bisphenol A-glycidyl methacrylate-induced generation of proinflammatory mediators through the MAPK and NF-κB pathways in macrophages.

Bisphenol A-glycidyl methacrylate (BisGMA) is a methacrylate monomer that is mainly used in three-dimensional structures to reconstruct dental and bony defects. BisGMA has toxic and proinflammatory effects on macrophages. Rutin is a natural flavonol glycoside that is present in various plants and has useful biological effects, such as anti-inflammatory, anticancer, and antioxidative effects. The aim of this study was to investigate the anti-inflammation of rutin in macrophages after exposure to BisGMA. Pretreatment of the RAW264.7 macrophage with rutin at 0, 10, 30, and 100 µM for 30 min before being incubated with BisGMA at 0 or 3 µM. Proinflammatory cytokines and prostaglandin (PG) E2 were detected by enzyme-linked immunosorbent assay (ELISA). Nitric oxide (NO) was detected by the Griess assay. Expression and phosphorylation of proteins were measured by Western blot assay. Pretreatment with rutin inhibited the BisGMA-induced generation of proinflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, and PGE2, in macrophages. Rutin also suppressed the BisGMA-induced secretion of NO and expression of inducible nitric oxide synthase (iNOS) in a concentration-dependent manner. Furthermore, rutin suppressed the mitogen-activated protein kinase (MAPK) phosphorylation in a concentration-dependent manner. Finally, rutin suppressed the BisGMA-induced phosphorylation of nuclear factor (NF)-κB p65 and degradation of inhibitor of κB (IκB). These results indicate that the concentration of rutin has an inhibitory effect on proinflammatory mediator generation, MAPK phosphorylation, NF-κB p65 phosphorylation, and IκB degradation. In conclusion, rutin is a potential anti-inflammatory agent for BisGMA-stimulated macrophages through NF-κB p65 phosphorylation and IκB degradation resulting from MAPK phosphorylation.

Protective Effect of Rutin on Triethylene Glycol Dimethacrylate-Induced Toxicity through the Inhibition of Caspase Activation and Reactive Oxygen Species Generation in Macrophages.

Rutin, also called quercetin-3-rhamnosyl glucoside, is a natural flavonol glycoside present in many plants. Rutin is used to treat various diseases, such as inflammation, diabetes, and cancer. For polymeric biomaterials, triethylene glycol dimethacrylate (TEGDMA) is the most commonly used monomer and serves as a restorative resin, a dentin bonding agent and sealant, and a bone cement component. Overall, TEGDMA induces various toxic effects in macrophages, including cytotoxicity, apoptosis, and genotoxicity. The aim of this study was to investigate the protective mechanism of rutin in alleviating TEGDMA-induced toxicity in RAW264.7 macrophages. After treatment with rutin, we assessed the cell viability and apoptosis of TEGDMA-induced RAW264.7 macrophages using an methylthiazol tetrazolium (MTT) assay and Annexin V-FITC/propidium iodide assay, respectively. Subsequently, we assessed the level of genotoxicity using comet and micronucleus assays, assessed the cysteinyla aspartate specific proteinases (caspases) and antioxidant enzyme (AOE) activity using commercial kits, and evaluated the generation of reactive oxygen species (ROS) using a dichlorodihydrofluorescein diacetate (DCFH-DA) assay. We evaluated the expression of heme oxygenase (HO)-1, the expression of nuclear factor erythroid 2 related factor (Nrf-2), and phosphorylation of AMP activated protein kinase (AMPK) using the Western blot assay. The results indicated that rutin substantially reduced the level of cytotoxicity, apoptosis, and genotoxicity of TEGDMA-induced RAW264.7 macrophages. Rutin also blocked the activity of caspase-3, caspase-8, and caspase-9 in TEGDMA-stimulated RAW264.7 macrophages. In addition, it decreased TEGDMA-induced ROS generation and AOE deactivation in macrophages. Finally, we found that TEGDMA-inhibited slightly the HO-1 expression, Nrf-2 expression, and AMPK phosphorylation would be revered by rutin. In addition, the HO-1 expression, Nrf-2 expression, and AMPK phosphorylation was enhanced by rutin. These findings indicate that rutin suppresses TEGDMA-induced caspase-mediated toxic effects through ROS generation and antioxidative system deactivation through the Nrf-2/AMPK pathway. Therefore, rutin has the potential to serve as a novel antitoxicity agent for TEGDMA in RAW264.7 macrophages.

Protective effect of wogonin on inflammatory responses in BisGMA-treated macrophages through the inhibition of MAPK and NFκB pathways.

Composites, resins, and sealants that are commonly used in orthopedics and dentistry are based on 2,2-bis[p-(2'-hydroxy-3'-methacryloxypropoxy)phenylene]propane (BisGMA), which induces proinflammatory responses in macrophages. The present study aimed to explore the anti-inflammatory responses of wogonin, which is a natural dihydroxyl flavonoid compound, in BisGMA-treated macrophages. According to the findings, wogonin exhibits anti-inflammatory, antiallergic, anticancer, and antioxidative properties. The generation of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS) were noted to be inhibited by wogonin in BisGMA-treated macrophages. Furthermore, the production of proinflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 was reduced. In addition, BisGMA-induced nuclear factor (NF)-κB p65 phosphorylation and inhibitor of κB (IκB) degradation were inhibited. Finally, the BisGMA-induced phosphorylation of mitogen-activated protein kinases (MAPKs), including p38 MAPK, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) was inhibited. All these effects were induced by wogonin in the macrophages in a concentration-dependent manner. Similar inhibitory effects of wogonin were observed on the production of NO and proinflammatory cytokines, expression of iNOS, phosphorylation of NF-κB p65 and MAPK, and degradation of IκB. These results indicated that rutin is a potential anti-inflammatory agent for BisGMA-treated macrophages that undergo NFκB p65 phosphorylation and IκB degradation through upstream MAPK phosphorylation. Therefore, wogonin inhibits BisGMA-induced proinflammatory responses in macrophages through the regulation of the NFκB pathway and its upstream factor, MAPK.

A nationwide register-based study of the prevalence of burning mouth syndrome in Taiwan from 2004 to 2013.

BACKGROUND/PURPOSE: Burning mouth syndrome (BMS) is defined as a chronic burning pain of the oral mucosa with no associated clinical signs or apparent extraneous cause. Limited epidemiologic data have been published. In this study, we probed the nationwide registered database to assess the prevalence of BMS in Taiwan. MATERIALS AND METHODS: A retrospective study was conducted to analyze the dental dataset compiled by the Taiwan's National Health Insurance Research Database from 2004 to 2013. The diagnosis of BMS was identified in accordance with the International Classification of Disease, Ninth revision. In addition, sex and age were analyzed by multivariate Poisson regression. RESULTS: The prevalence of BMS revealed from 2.24 (per 104) to 3.11 (per 104) over past 10 year period. Female has higher risk of BMS than male (RR: 1.39; 95% CI: 1.37-1.41). The 50-59 years old group, 60-69 years old group, and >70 years old group had 1.55-, 2.06-, and 2.58-fold risk than 40-49 years old group for BMS (p < 0.001), respectively. CONCLUSION: Taken together, this is the first reported nationwide population based prevalence data for BMS in Taiwan. The risk for BMS is highly associated with female and advancing age.

The regulation of Oct4 in human gingival fibroblasts stimulated by cyclosporine A: Preliminary observations.

BACKGROUND/PURPOSE: Oct4, a key transcription factor, could reprogram human somatic fibroblasts into embryonic stem cell-like pluripotent cells. The exact mechanism of cyclosporine A (CsA)-induced gingival overgrowth is still unclear. The aim of this study was to investigate the effects of CsA on the expression of Oct4 in cultured human gingival fibroblasts (HGFs) in vitro. MATERIALS AND METHODS: The effects of CsA on HGFs were used to elucidate whether Oct4 expression could be induced by CsA by using quantitative real-time reverse transcription-polymerase chain reaction and western blot. Cell growth in CsA-treated HGFs with Oct4 lentiviral-mediated shRNAi knockdown was evaluated by tetrazolium bromide reduction assay. RESULTS: CsA was found to upregulate Oct4 transcript in a dose-dependent manner (p < 0.05). CsA also dose-dependently increased Oct4 protein expression (p < 0.05). The lentivirus expressing sh-Oct4 successfully prevented the CsA-induced Oct4 mRNA and protein in HGFs (p < 0.05). However, knockdown of Oct4 was insufficient to inhibit CsA-stimulated cell growth in HGFs. Furthermore, double knockdown with pluripotency-associated transcription factor Nanog showed that the down-regulation of Oct4/Nanog by lentiviral infection significantly inhibited CsA-stimulated cell growth (p < 0.05). CONCLUSION: Taken together, CsA was first found to upregulate Oct4 mRNA and protein expression in HGFs. The silencing Oct4 could not suppress cell growth unless Nanog was repressed simultaneously.

Trends, demographics, and conditions of emergency dental visits in Taiwan 1997-2013: A nationwide population-based retrospective study.

BACKGROUND/PURPOSE: The disparate or irregular dental care was associated with acute clinical problems that may lead to care seeking for emergency visits. The aim of this study was to determine the time trends, demographics, and conditions of emergency dental (ED) visits in Taiwan. METHODS: This cross-sectional study was conducted to analyze the insurance reimbursement of dental care services in National Health Insurance Research Database. The demographic characteristics and age-period effects of ED visits were estimated by multivariate Poisson regression. In addition, the top causes of ED visits were evaluated and stratified by traumatic and non-traumatic conditions. RESULTS: The prevalence of ED visits were 3.18, 5.44, and 4.83 (per 10,000 persons) in 1997, 2002, and 2013, respectively. The primary diagnosis code for ED visits was 522 'pulp and periapical tissues'. Pulpitis (522.0), cellulitis (528.3), acute periodontitis (523.3), and caries (521.0) were the top 4 non-traumatic reasons for seeking ED visits. The top 3 traumatic conditions were open wound of internal structures of mouth without mention of complication (873.6), open wound of face without mention of complication (873.4), and loss of teeth due to trauma (525.1). The higher prevalence of ED visits were found in male (aRR = 1.50, 95% CI: 1.49-1.51), 6 y/o group (aRR = 1.56, 95% CI: 1.53-1.59), east region (aRR = 1.27, 95% CI: 1.25-1.29), and dependent coverage group (aRR = 1.16, 95% CI: 1.14-1.19). CONCLUSION: Taken together, these demographic data could serve as a reference for the authorities concerned to improve the current situation of ED in Taiwan.

Changes in prevalence of precancerous oral submucous fibrosis from 1996 to 2013 in Taiwan: A nationwide population-based retrospective study.

BACKGROUND/PURPOSE: Oral submucous fibrosis (OSF) has been regarded as a precancerous condition. Research examining the prevalence of OSF could be the first step in preventing or reducing malignant transformation. In this study, we probed a nationwide registered database to assess the prevalence, gender distribution, age, income, and urbanization status of OSF patients in Taiwan. METHODS: A retrospective study was conducted to analyze the registered database compiled by the National Health Insurance provided by the Ministry of Health and Welfare, Taiwan. We identified dental visit patients diagnosed with OSF during the period between January 1, 1996 and December 31, 2013. In addition, demographic characteristics were analyzed by multivariate Poisson regression. RESULTS: The prevalence of OSF increased significantly from 8.3 (per 105) in 1996 to 16.2 (per 105) in 2013 (p < 0.0001). Men had a significantly higher OSF prevalence than women (p < 0.001). The mean age of patients with OSF increased from 1996 to 2013. Individuals living in rural areas had a higher risk of OSF compared with those living in urban areas [relative risk (RR), 1.10; 95% confidence interval (CI), 1.07-1.13]. The higher income group had a lower risk of OSF compared with the lower income group (RR, 0.76; 95% CI, 0.73-0.80). CONCLUSION: This large-scale government-centered survey demonstrates that the prevalence of OSF in Taiwan significantly increased from 1996 to 2013. The prevalence was higher among men than among women.

Trends in the prevalence of periodontitis in Taiwan from 1997 to 2013: A nationwide population-based retrospective study.

Periodontitis is one of the most prevalent oral diseases. In this study, we probed the nationwide registered database to assess the time trends of prevalence of periodontitis in Taiwan.A retrospective study was conducted to analyze the registered database compiled by the National Health Insurance provided by the Department of Health, Taiwan, from 1997 to December 2013.We found that the prevalence of periodontitis significantly increased from 11.5% in 1997 to 19.59% in 2013 (P for trend < .0001). The mean age ±â€Šstandard deviation with periodontitis from 1997 to 2013 was 54.46 ±â€Š14.47 and 45.51 ±â€Š16.58 years old, respectively. The proportion of individuals with periodontitis in age group >65 years old decreased markedly. The proportion of individuals with periodontitis in age groups <25 and 26 to 35 years old demonstrated an increased pattern. Compared to the reference cohort of 1953 to 1957, the recent birth cohort of 1993 to 1997 revealed the highest relative risk (RR) of periodontitis (male: RR, 67.42, 95% confidence interval [CI], 17.04-266.76; female: RR, 65.85, 95% CI, 16.70-259.70). Both male and female groups showed the similar age-effect pattern in the cross-sectional age curve from age-period-cohort model. There was an upturn with advancing age up to 40 to 50 years old and then a downward trend in both genders. Population dwelling in suburban area (RR, 0.95; 95% CI, 0.94-0.97) and rural area (RR, 0.97; 95% CI, 0.95-0.99) had the lower risk of periodontitis than those who lived in urban area. The higher income group revealed the higher risk of periodontitis compared with lower income group (RR, 1.20; 95% CI, 1.18-1.23).The prevalence of periodontitis significantly increased in Taiwan over past 17 years. The mean age with periodontitis was shown in a decreased pattern. The use of a nationwide population-based database could provide sufficient sample size, generalizability, and statistical power to assess the periodontal status in Taiwan.

Increased risk of periodontitis in patients with psoriatic disease: a nationwide population-based retrospective cohort study.

AIMS: Periodontitis and psoriatic disease, including psoriasis (PS) and psoriatic arthritis (PsA), share the common risk factors and co-morbidities. However, the risk of periodontitis in patients with psoriatic disease still needs further investigation. This study was a nationwide population-based retrospective cohort study assessing the risk of periodontitis from psoriatic disease exposure. MATERIALS AND METHODS: Patients with newly diagnosed psoriatic disease from 2003 to 2012 were identified from the Taiwanese National Health Insurance Research Database. The 1:4 ratio propensity score matched controls were selected from no psoriatic disease participations. The subsequent risk of periodontitis was evaluated in exposure and comparison groups. Multiple Cox proportional hazard models were used for the estimation. RESULTS: A total of 3,487 psoriatic disease patients and 13,948 controls were identified. Incidence rate of periodontitis was higher in patients with PsA. The adjusted hazard ratio (aHRs) for moderate/severe periodontitis were 0.85 (95% CI [0.65-1.11]) in PS group and 1.66 (95% CI [0.99-2.78]) in PsA group. The aHRs of PsA were increased over time, aHRs was changed from 0.65 (0-11 months from index date) to 1.34 (≥12 months from index date) in all types of periodontitis and from 1.09 to 1.79 in moderate/severe periodontitis group, respectively. CONCLUSIONS: The increased risk of periodontitis was observed, especially the association between PsA and moderate/severe periodontitis. The patients with psoriatic disease should receive regular periodontal evaluation.

Malignant transformation of oral submucous fibrosis in Taiwan: A nationwide population-based retrospective cohort study.

BACKGROUND: Oral submucous fibrosis (OSF) is one of the well-recognized oral potentially malignant disorders. In this study, we investigated the malignant transformation of OSF in a Taiwanese population. METHODS: A retrospective cohort study was analyzed from Taiwan's National Health Insurance Research Database. A comparison cohort was randomly frequency-matched with the OSF cohort according to age, sex, and index year. Oral leukoplakia (OL) was further stratified to evaluate for the possible synergistic effects of OSF-associated malignant transformation. RESULTS: In this cohort, 71 (9.13%) of 778 cases of OSF were observed to transform into oral cancer. The malignant transformation rate was 29.26-fold in the OSF cohort than in the comparison cohort after adjustment (95% confidence intervals 20.55-41.67). To further stratify with OL, OSF with OL (52.46%; 95% confidence intervals 34.88-78.91) had higher risk of malignant transformation rate than OSF alone (29.84%; 95% confidence intervals 20.99-42.42). The Kaplan-Meier plot revealed the rate free of malignant transformation was significant over the 13-year follow-up period (log-rank test, P<.001). The mean duration of malignant transformation was 5.1, 2.7, and 2.2 years for non-OSF, OSF alone, and OSF with OL, respectively. CONCLUSION: Oral submucous fibrosis patients exhibited a significantly higher risk of malignant transformation than those without OSF. OL could enhance malignant transformation in patients with OSF.

Upregulation of embryonic stem cell marker Nanog in human gingival fibroblasts stimulated with cyclosporine A: An in vitro study.

BACKGROUND/PURPOSE: Gingival overgrowth is a common side effect of medication with the immunosuppressant cyclosporine A (CsA). This study proposed to verify whether Nanog, an embryonic stem cell marker, contributes to gingival overgrowth stimulated with CsA in human gingival fibroblasts (HGFs). MATERIALS AND METHODS: The effect of CsA on HGFs was used to elucidate whether Nanog expression could be induced by CsA using quantitative real-time reverse transcription-polymerase chain reaction and Western blotting. Cell growth in CsA-treated HGFs with Nanog lentivirus-mediated short hairpin RNA interference knockdown was evaluated by tetrazolium bromide reduction assay. RESULTS: CsA upregulated Nanog transcript in HGFs in a dose-dependent manner (P < 0.05). CsA was also shown to increase Nanog protein expression in HGFs in a dose-dependent manner (P < 0.05). In addition, downregulation of Nanog by lentiviral infection significantly inhibited CsA-stimulated cell growth in HGFs (P < 0.05). CONCLUSION: CsA upregulated Nanog expression and cell growth in HGFs, while silencing Nanog effectively reversed these phenomena. Nanog may act as a major switch in the pathogenesis of CsA-induced gingival overgrowth.

Trends in the prevalence of diagnosed temporomandibular disorder from 2004 to 2013 using a Nationwide health insurance database in Taiwan.

BACKGROUND/PURPOSE: Temporomandibular disorder (TMD) is defined as various clinical signs and symptoms involving the masticatory muscles, the temporomandibular joint and associated structures. The aim of this study was to investigate the prevalence of diagnosed TMD in Taiwan using a National Health Insurance Research Database from 2004 to 2013. MATERIALS AND METHODS: A retrospective study was conducted to analyze the registered database compiled by the National Health Insurance from 2004 to 2013. The diagnosis of TMDs was identified in accordance with the International Classification of Disease, Ninth revision (ICD-9-CM 524.6). The relative risk of TMD from 2004 to 2013 after adjusting for year, age, and gender was evaluated by logistic regression analysis. RESULTS: The prevalence of TMD increased significantly from 14 (per 104) to 26 (per 104) over the past 10 year period [odds ratio (OR), 1.07; 95% confidence interval (CI), 1.04-1.09]. The mean age with TMD from 2004 to 2013 was 52.31 ± 17.15 years and 45.12 ± 17.32 years, respectively. The female group had a higher risk of TMD than the male group (OR, 1.70; 95% CI, 1.49-1.94). CONCLUSION: Taken together, the estimated prevalence of TMD significantly increased from 2004 to 2013 in Taiwan. In addition, the risk for TMD was higher among women than among men.