The bond strength to the silicate-based CAD/CAM blocks may be affected by the composition and microstructure of the silicatebased blocks, surface treatment, and the properties of the applied adhesive. In this study, the shear bond strength to the silicate blocks with various universal adhesives after sandblasting or HF-treatment was measured, and the effects of the additional silane application after surface treatments are evaluated. Six silica-containing blocks and five universal adhesives currently used in dental clinics were selected. After polishing the silicate block surface, the specimens were divided into two groups. The first groups were HF-treated and the second groups were sandblasted with alumina, and the surface roughness, contact angle, and microstructure were analyzed by CLSM (Confocal Laser Scanning Microscope), contact angle analyzer, and FE-SEM (Field Emission Scanning Electron Microscope).Composite resin (2 mm diameter) was bonded with universal adhesive to silicate blocks and stored in a 37 ℃ water bath for 24 hours, and the shear bond strength was measured using a universal testing machine. The measured values were statistically analyzed using the Tukey-multiple comparison test (α=0.05). For hybrid composite ceramics, there was no significant difference in bond strength between sandblasting or HF-treatment, and additional silane application may not be necessary when bonding with a universal adhesive, whereas for leucite-reinforced and lithium disilicate glass-ceramics, HF-treatment may be more favorable for adhesion than sandblasting, and additional silane application appears to be necessary even when applying a universal adhesive.

The shear bond strength of the composite resin to a CAD/CAM hybrid composite resin block (CRB) can be affected by the composition and microstructure of the hybrid CRB, surface treatment and the properties of the applied adhesive. In this study, the shear bond strengths between composite resin and the hybrid CRBs were measured to evaluate the effect of microstructure differences in hybrid CRBs on the bond strength. Ten conventional and reinforced hybrid CRBs developed by five domestic and international manufacturersand five universal adhesives currently used in dentistry were selected. After polishing the hybrid CRB surface, the specimens were divided into two groups. The first group was HF-treated to observe the microstructure by FE-SEM, and the second group was sandblasted with alumina, measured the surface roughness by CLSM, bonded with composite resin (diameter = 2.0mm) using universal adhesive, and stored in a 37 ℃ water bath for 24 hours, and measured the shear bond strength using a universal testing machine. The measured values were statistically analyzed using the Tukey-multiple comparison test (α= 0.05). It was observed that the size, type, and fraction of the filler particles contained in the regular and reinforced hybrid CRBs affected the microstructure, but the differences did not affect the shear bond strength. All five universal adhesives containing 10-MDP as the main functional monomer met the minimum bond strength (>20 MPa) required for clinical applications.

Enamel demineralization represents the most prevalent complication arising from fixed orthodontic treatment. Its main etiology is the development of cariogenic biofilms formed around orthodontic appliances. Ordinarily, oral biofilms exist in a dynamic equilibrium with the host's defense mechanisms. However, the equilibrium can be disrupted by environmental changes, such as the introduction of a fixed orthodontic appliance, resulting in a shift in the biofilm’s microbial composition from non-pathogenic to pathogenic. This alteration leads to an increased prevalence of cariogenic bacteria, notably mutans streptococci, within the biofilm. This article examines the relationships between oral biofilms and orthodontic appliances, with a particular focus on strategies for effectively managing oral biofilms to mitigate enamel demineralization around orthodontic appliances.

Purpose: : This study aims to investigate the status of delirium intervention in adult intensive care unit (ICU) patients and the perception of this delirium by medical staff. Methods: : This retrospective study involves 185 patients, whereas, a descriptive survey is conducted with 197 medical staff members. Results: : The delirium group includes 100 patients (54.1%). The incidence of delirium is 64.9% in the medical ICU, 65.9% in the surgical ICU, 42.4% in the neuro ICU, and 46.5% in the cardiac ICU. The percentages of delirium prevention intervention differs between the two groups: 65.0% in the delirium group and 95.3% in the non-delirium group. The medical staff recognize that delirium is a common problem in the ICU (100.0%) and requires active medical intervention (98.5%). Conclusion : The length of stay at the ICU is longer in the delirium group than in the non-delirium group. It is necessary to standardize delirium prevention and treatment protocols to be equally applicable to all ICU patients.

This study aimed to analyze the eluted components of syringe-type bis-acryl composites and to evaluate the effect of removing the oxygen-inhibited layer on cytotoxicity. Four different bis-acryl provisional composite materials-Protemp 4 (PT), Structur 2 SC (ST), Luxatemp Automix Plus (LT), and Hexa-Temp (HT)-were evaluated. Gas chromatography/mass spectrometry was used to analyze the composite eluate after 24 h of immersion in methanol. An agar overlay test and a live/dead assay were performed on the polymerized disc-shaped specimens after 24 h. To evaluate the effect of removing the oxygen-inhibited layer, samples were prepared with a surface oxygen-inhibited layer. The surface oxygen-inhibited layer of the disc-shaped specimens was removed with alcohol only (subgroup A) or with polishing and alcohol (subgroup PA), and their cytotoxicities were compared with those of “as received” (subgroup N) specimens using the WST-1 assay. Statistical significance was assessed using analyses of variance, followed by Bonferroni multiple comparison tests (α=0.05). Different components were detected by gas chromatography/mass spectrometry analysis among the groups. The agar overlay assay confirmed severe cytotoxicity in HT, LT, and ST groups, whereas PT showed moderate cytotoxicity. The effect of removing the oxygen-inhibited layer on cell viability was significantly higher in PA than in N in all composite groups. In HT and ST, the cell viability was significantly higher in PA than in A. Syringe-type bis-acryl composites for provisional restorations may elute various components into the oral cavity, which may cause cytotoxicity in adjacent structures. The cytotoxicity of the materials is reduced by the removal of the oxygen-inhibited layer.

The purpose of this study was to compare physical and biodegradable properties of 3D printed resorbable membranes that are used for guided tissue regenerations in periodontal tissues. Three types of 3D printed membranes (two types of non β-TCP and one type of β-TCP) were considered. The form and element compositions of 3D printed membranes were analyzed by field-emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray spectroscopy (EDS). Porosity and pore size were measured using Micro-CT. Also, tensile strength, biodegradability tests were performed. Statistical analyses were carried in tensile strength and cell viability test (p<0.05). The result of SEM images with EDS analyses showed linear layers of lattice structure with presence of C and O in all groups. There was a slight difference in Ca and P among some groups. Tensile strength was significantly different among all groups (p<0.05), and biodegradability showed that the group containing β-TCP resulted in the fastest degradation rate. Therefore, the results of this study concluded that the 3D printed resorbable membrane has variable physical and biodegradable properties for clinical use, where such information would be useful to be considered for the future development of related products and clinical application of the products.

The purpose of this study was to compare physical and biodegradable properties of 3D printed resorbable membranes that are used for guided tissue regenerations in periodontal tissues. Three types of 3D printed membranes (two types of non β-TCP and one type of β-TCP) were considered. The form and element compositions of 3D printed membranes were analyzed by field-emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray spectroscopy (EDS). Porosity and pore size were measured using Micro-CT. Also, tensile strength, biodegradability tests were performed. Statistical analyses were carried in tensile strength and cell viability test (p<0.05). The result of SEM images with EDS analyses showed linear layers of lattice structure with presence of C and O in all groups. There was a slight difference in Ca and P among some groups. Tensile strength was significantly different among all groups (p<0.05), and biodegradability showed that the group containing β-TCP resulted in the fastest degradation rate. Therefore, the results of this study concluded that the 3D printed resorbable membrane has variable physical and biodegradable properties for clinical use, where such information would be useful to be considered for the future development of related products and clinical application of the products.

The purpose of this study was to measure the transmittance change of composites during light curing in real time according to different shades and thicknesses. An instrument using pulse width modulation-curing light was developed to measure the transmittance of composites in real time. A micro-hybrid composite, Filtek Z250, was used for %transmittance measurement with five different shades (A1, A2, A3, A3.5, A4) and 4 different thicknesses (0.16, 0.5, 1.0, 1.5 mm). The maximum value of d(%Transmittance)/dt and peak time were used to observe polymerization kinetics. Attenuation coefficient was also compared between pre and post cured specimens. The transmittance increased in all specimens after polymerization. A2 showed the highest and A1 showed the lowest transmittance in both pre and post curing. The transmittance change and maximum rate of change were highest in A2 and lowest in A3.5, and the peak time, which ranged in 3.10 to 4.07, was not significantly different among shades. As the specimen became thinner, both the transmittance and rate of change increased, and the peak time was maximum at 1.5 mm thickness. The absolute value of attenuation coefficient decreased after polymerization in all specimens. In conclusion, the transmittance of composite increased after polymerization. Each shade showed different transmittance value for both pre and post curing state, and thinner specimen showed higher transmittance value. Polymerization kinetics could also be observed through the rate of transmittance change over time.

The purpose of this study was to measure the transmittance change of composites during light curing in real time according to different shades and thicknesses. An instrument using pulse width modulation-curing light was developed to measure the transmittance of composites in real time. A micro-hybrid composite, Filtek Z250, was used for %transmittance measurement with five different shades (A1, A2, A3, A3.5, A4) and 4 different thicknesses (0.16, 0.5, 1.0, 1.5 mm). The maximum value of d(%Transmittance)/dt and peak time were used to observe polymerization kinetics. Attenuation coefficient was also compared between pre and post cured specimens. The transmittance increased in all specimens after polymerization. A2 showed the highest and A1 showed the lowest transmittance in both pre and post curing. The transmittance change and maximum rate of change were highest in A2 and lowest in A3.5, and the peak time, which ranged in 3.10 to 4.07, was not significantly different among shades. As the specimen became thinner, both the transmittance and rate of change increased, and the peak time was maximum at 1.5 mm thickness. The absolute value of attenuation coefficient decreased after polymerization in all specimens. In conclusion, the transmittance of composite increased after polymerization. Each shade showed different transmittance value for both pre and post curing state, and thinner specimen showed higher transmittance value. Polymerization kinetics could also be observed through the rate of transmittance change over time.

Though clinical practice guidelines (CPGs) for cardiac rehabilitation (CR) are an effective and widely used treatment method worldwide, they are as yet not widely accepted in Korea. Given that cardiovascular (CV) disease is the second leading cause of death in Korea, it is urgent that CR programs be developed. In 2008, the Government of Korea implemented CR programs at 11 university hospitals as part of its Regional Cardio-Cerebrovascular Center Project, and 3 additional medical facilities will be added in 2019. In addition, owing to the promotion of CR nationwide and the introduction of CR insurance benefits, 40 medical institutions nationwide have begun CR programs even as a growing number of medical institutions are preparing to offer CR. The purpose of this research was to develop evidence-based CPGs to support CR implementation in Korea. This study is based on an analysis of CPGs elsewhere in the world, an extensive literature search, a systematic analysis of multiple randomized control trials, and a CPG management, development, and assessment committee comprised of thirty-three authors—primarily rehabilitation specialists, cardiologists, and thoracic surgeons in 21 university hospitals and 2 general hospitals. Twelve consultants, primarily rehabilitation, sports medicine, and preventive medicine specialists, CPG experts, nurses, physical therapists, clinical nutritionists, and library and information experts participated in the research and development of these CPGs. After the draft guidelines were developed, 3 rounds of public hearings were held with staff members from relevant academic societies and stakeholders, after which the guidelines were further reviewed and modified. CR involves a more cost-effective use of healthcare resources relative to that of general treatments, and the exercise component of CR lowers CV mortality and readmission rates, regardless of the type of coronary heart disease and type and setting of CR. Individualized CR programs should be considered together with various factors, including differences in heart function and lifestyle, and doing so will boost participation and adherence with the CR program, ultimately meeting the final goals of the program, namely reducing the recurrence of myocardial infarction and mortality rates.