Objectives
The purpose of this study was to identify the age, period and cohort effects on the changes in oral health status in South Koreans.
Methods
The age, period and cohort analysis (APC ...analysis) of the oral health status was conducted using an aggregated age‐by‐time period table. The age‐by‐time period table was formulated using data from the Korea National Oral Health Survey (KNOHS) 2000 and 2006, and the Korea National Health and Nutrition Examination Survey (KNHANES) 2010 and 2015. Two oral health outcomes were measured: the number of teeth and Decayed‐Missing‐Filled Teeth (DMFT) index. Descriptive analysis by graphical representation and partial least square (PLS) regression was used for APC analysis.
Results
Both graphical description and PLS regression showed age and cohort effects in oral health status with the number of teeth decreasing and the DMFT index increasing with age. No period effects were found in either index. The number of teeth increased in the recent birth cohorts. However, the DMFT index showed a reverse J‐shaped trend, which worsened in recent birth cohorts. The DMFT index increase in the recent cohort was mainly attributed by an increase in the FT index.
Conclusions
The effects of age on the number of teeth and caries highlight the importance of oral health in adulthood. The increased caries experience in recent cohorts may indicate the limitations of the current oral health policy. It would be relevant to explore what determinants cause the changes in oral health status. Future oral health policies should address the new directions to reduce the burden of oral diseases.
This in vitro study aimed to evaluate the feasibility of quantitative light-induced fluorescence (QLF) technology for detecting the presence and severity of microleakage of pit and fissure sealants. ...The areas of interest (AOIs) were 160 pits and fissures of 40 extracted permanent teeth. Fluorescent images were acquired using a QLF device, and the maximum fluorescence loss ΔF
of each AOI was analyzed. After staining and cross-sectioning of the teeth, histological dye penetration was scored on a scale of 0 to 3. The relationship between ΔF
and microleakage depth was analyzed, and the areas under the curve (AUCs) were calculated. The │ΔF
│ increased as microleakage depth increased. The ΔF
values of microleakage areas showed a strong significant correlation with the histological scores of dye penetration (r = - 0.72, P = 0.001). AUC analysis showed a high diagnostic accuracy for microleakage depth (AUC = 0.83-0.91). The highest AUC of 0.91 was found when differentiating the outer half microleakage of the sealant (histological score 0 vs. 1-3). QLF technology is effective in assessing the presence and severity of microleakage, suggesting its potential for noninvasive detection and monitoring of sealant microleakage in clinical settings.
Background: Some previous studies reported hearing ability can be reduced by impaired masticatory ability, but there has been little evidence reported of an association between hearing loss and ...unilateral mastication. Therefore, this study aimed to investigate the relationship between unilateral mastication (UM), estimated from individual functional tooth units (FTUs), and hearing loss in a representative sample of Korean adults. Methods: The analyzed data were obtained from 1,773 adults aged 40–89 years who participated in Korean national survey. Hearing loss was defined as a pure-tone average of >25 dB at frequencies of 0.5, 1, 2, and 4 kHz in either ear. In each subject, UM was calculated as the difference in the sums of the FTU scores, which is an index of posterior tooth occlusion, on the two sides of the oral cavity. The scores were used to classify the UM into low, moderate, and high. The adjusted odds ratios (aORs) and their 95% confidence intervals (CIs) were calculated in multivariable logistic regression analyses. Results: When controlling for sociodemographic factors, the aOR for hearing loss was 3.12 (95% CI, 1.21–8.03) for high UM relative to low UM. This association remained in a fully-adjusted model containing factors related to noise exposure (aOR 2.88; 95% CI, 1.12–7.46). Conclusion: Adults with high UM as measured using FTUs showed a higher occurrence of hearing loss than those with low UM.
Electrochemical reduction of carbon dioxide (CO2) to formate (HCOO–) in aqueous solution is studied using tin–lead (Sn–Pb) alloys as new electrocatalysts. In electrochemical impedance spectroscopy ...(EIS) measurements, lower charge-transfer resistance is observed for the alloy electrodes when compared to the single metal electrodes such as Sn and Pb. The results of X-ray photoelectron spectroscopy (XPS) and cyclic voltammetric (CV) analysis show that the Sn in the Sn–Pb alloys facilitates the formation of oxidized tin (SnO x ) and metallic lead (Pb0) on the alloy surface by inhibiting the formation of low-conductive lead oxide (PbO) film. The CV analysis confirms that the Sn–Pb alloys exhibit higher reduction current than the single metal electrodes under CO2 atmosphere. The Faradaic efficiency (FE) and the partial current density (PCD) of HCOO– production on the alloy electrodes is investigated by electroreduction experiments at −2.0 V (vs Ag/AgCl) in an H-type cell. As results, respectively more than 16% and 25% higher FE and PCD of HCOO– are obtained from the Sn–Pb alloys compared to the single metal electrodes. A Sn–Pb alloy including surface composition of Sn56.3Pb43.7 exhibits the highest FE of 79.8% with the highest PCD of 45.7 mA cm–2.
Abstract Objective The aim of this study was to investigate whether Quantitative Light-induced Fluorescence-Digital (QLF-D) could monitor the degree of maturation of dental microcosm biofilms by ...observing the red fluorescence emitted from the biofilms. Methods Dental microcosm the biofilms were grown on bovine enamel discs. They were initiated from human saliva, and then grown in 0.5% sucrose growth media for 10 days. On days 1, 2, 3, 7, and 10 after the inoculation, fluorescence images of the biofilms were captured using the QLF-D and the red fluorescence intensity was quantified by calculating the red/green ratio (R/G value). Total and aciduric bacteria within the biofilms were counted, and the degree of demineralization was evaluated by measuring the percentage of surface microhardness change (ΔVHN) and lesion depth in the enamel. Results The R/G values of the biofilms assessed by the QLF-D increased significantly over time up to 7 days after inoculation ( p < 0.0001). The R/G values showed significant positive correlations with the total bacterial CFUs ( r = 0.74, p = 0.001), aciduric bacterial CFUs ( r = 0.85, p = 0.001), ΔVHN ( r = 0.65, p = 0.001), and lesion depth in the enamel ( r = 0.82, p = 0.001) according to the maturation time. Conclusions The red fluorescence detected by the QLF-D increased according to biofilm maturation and was significantly associated with the cariogenicity of the biofilm. Therefore, this device could be used to monitor the degree of biofilm maturation by observing the red fluorescence emitted from cariogenic biofilms. Clinical significance The QLF-D enables the detection of a mature dental plaque and monitoring of its cariogenic status by observing the plaque fluorescence non-destructively, in real time.
To prolong tooth life expectancy, tooth wear resulting in dentin exposure should be detected early. However, the most objective methods are clinically limited. We validated fluorescence parameters ...for distinguishing enamel from dentin-exposed wear in clinical images.
Quantitative light-induced fluorescence (QLF) images of 73 adults (age range: 22–48 years, mean: 33.81 ± 7.71 years), including 1949 teeth with varying tooth wear degrees, without restorations, caries, or cusp area fractures, were used to calculate the ΔFwear values. Areas-of-interest (AOIs) were selected from QLF images; the ΔFwear values and the tooth wear index (TWI) were calculated for each tooth. The ΔFwear values were compared according to the TWI scores. The optimum ΔFwear values for distinguishing enamel and dentin-exposed wear were determined using the receiver operating characteristic (ROC) curve analysis.
Overall, 1949 AOIs were evaluated. The median ΔFwear values for teeth with TWI scores 0, 1, and 2 (5.7 %, 10.3 %, and 17.0 %) differed significantly (P < 0.001). The optimum cutoff ΔFwear values were 12.1 and 14.7 in the anterior and posterior teeth, respectively; the corresponding areas under the ROC values (AUROCs) were 0.86 and 0.93 (sensitivity: 0.79 and 0.85; specificity: 0.79 and 0.85, respectively). The ΔFwear cutoff values for different age groups were within a range (12.7–13.7) and showed high validity (sensitivity, specificity, and AUROC: 0.78, 0.77–0.78, and 0.87–0.88, respectively).
At the optimum threshold, the ΔFwear values showed high validity for distinguishing dentin exposure in worn teeth (AUROC: 0.87‒0.93) and could determine pathological tooth wear, particularly in posterior teeth.
We demonstrated the feasibility of using QLF to detect dentin-exposed tooth wear and present optimal thresholds according to age. In addition, we confirmed the possibility using such image data for objective and cost-effective epidemiological investigation and application in tele-dentistry.
Abstract Introduction The ability to accurately detect tooth cracks and quantify their depth would allow the prediction of crack progression and treatment success. The aim of this in vitro study was ...to determine the capabilities of quantitative light-induced fluorescence (QLF) technology in the detection of enamel cracks. Methods Ninety-six extracted human teeth were selected for examining naturally existing or suspected cracked teeth surfaces using a photocuring unit. QLF performed with a digital camera (QLF-D) images were used to assess the ability to detect enamel cracks based on the maximum fluorescence loss value (ΔFmax , %), which was then analyzed using the QLF-D software. A histologic evaluation was then performed in which the samples were sectioned and observed with the aid of a polarized light microscope. The relationship between ΔFmax and the histology findings was assessed based on the Spearman rank correlation. The sensitivity and specificity were calculated to evaluate the validity of using QLF-D to analyze enamel inner-half cracks and cracks extending to the dentin-enamel junction. Results There was a strong correlation between the results of histologic evaluations of enamel cracks and the ΔFmax value, with a correlation coefficient of 0.84. The diagnostic accuracy of QLF-D had a sensitivity of 0.87 and a specificity of 0.98 for enamel inner-half cracks and a sensitivity of 0.90 and a specificity of 1.0 for cracks extending to the dentin-enamel junction. Conclusions These results indicate that QLF technology would be a useful clinical tool for diagnosing enamel cracks, especially given that this is a nondestructive method.
•TBAC forms semiclathrates with CH4 and CO2.•The highest stabilization of TBAC semiclathrates was observed at 3.3mol%.•The inclusion of CH4 and CO2 in semiclathrates was examined via spectroscopic ...methods.•TBAC semiclathrates can be applied to gas storage and CO2 capture.
The enclathration of guest gases such as CH4 and CO2 in tetra-n-butyl ammonium chloride (TBAC) semiclathrates and their potential application to natural gas storage and CO2 capture were examined with a primary focus on stability condition measurements and cage filling characteristics. The phase behaviors clearly demonstrated that the double CH4 (or CO2)+TBAC semiclathrates yielded a significantly enhanced thermodynamic stability. In particular, the highest stabilization occurred at 3.3mol%, the stoichiometric concentration of TBAC·29.7H2O. The cage-dependent 13C NMR chemical shift identified CH4 molecules enclathrated in the small 512 cages of the double TBAC semiclathrates. CO2 inclusion in the double TBAC semiclathrate was also confirmed using Raman spectroscopy. In addition, the dissociation enthalpy and the dissociation temperature of the TBAC semiclathrate under atmospheric pressure were measured to be 204.8±1.7J/g and 288.0K, respectively, by a differential scanning calorimeter. The experimental results demonstrate that TBAC semiclathrates can potentially be used for gas storage and CO2 capture due to their high thermodynamic stability and favorable enclathration characteristics of guest gases.
Silver-impregnated TiO₂/nylon-6 nanocomposite mats exhibit excellent characteristics as a filter media with good photocatalytic and antibacterial properties and durability for repeated use. Silver ...nanoparticles (NPs) were successfully embedded in electrospun TiO₂/nylon-6 composite nanofibers through the photocatalytic reduction of silver nitrate solution under UV-light irradiation. TiO₂ NPs present in nylon-6 solution were able to cause the formation of a high aspect ratio spider-wave-like structure during electrospinning and facilitated the UV photoreduction of AgNO₃ to Ag. TEM images, UV–visible and XRD spectra confirmed that monodisperse Ag NPs (approximately 4nm in size) were deposited selectively upon the TiO₂ NPs of the prepared nanocomposite mat. The antibacterial property of a TiO₂/nylon-6 composite mat loaded with Ag NPs was tested against Escherichia coli, and the photoactive property was tested against methylene blue. All of the results showed that TiO₂/nylon-6 nanocomposite mats loaded with Ag NPs are more effective than composite mats without Ag NPs. The prepared material has potential as an economically friendly photocatalyst and water filter media because it allows the NPs to be reused.
Introduction The aim of this study was to assess the association between malocclusion and oral health–related quality of life in young adults without orthodontic treatment, controlling for ...sociodemographic factors and common oral diseases. Methods The sample consisted of 429 Korean patients (328 men, 101 women) 18 to 32 years of age. They completed the Korean version of the oral health impact profile-14 questionnaire and had a clinical examination, including an assessment with the index of orthodontic treatment need−dental health component. We collected sociodemographic information (age, sex, and education level) and evaluated other common oral diseases (decayed, missing, and filled teeth; periodontal health status; temporomandibular disorder; and oral soft tissue diseases). Results Multiple logistic regression analysis showed that patients requiring extensive orthodontic treatment were more than 2.7 times as likely to have poor oral health–related quality of life as the corresponding “no treatment needed” reference group (odds ratio, 2.74; 95% confidence interval, 1.60-4.59; P <0.001). Severe malocclusion is significantly associated with functional limitations, physical pain, and social disability in young adults. Conclusions Malocclusion is a key factor associated with poor quality of life caused by limited oral function, pain, and social disability in young adults.
PDF
