Résumé
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.
Résumé
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.
Résumé
Purpose@#This study was conducted to assess the effects of a personalized nutritional intervention program on food security and health and nutritional status of elderly people in the city of Seoul. @*Methods@#A total of 372 elderly adults aged 65 years or above who resided in Seoul were enrolled in this study. Personalized supplementary food supply and nutritional education based on chronic disease status, disability and cooking ability were implemented for 4 months. To evaluate the effectiveness of the program, nutrient intake, food security status, anemia status, chronic disease management, and frailty status, and prevalence of malnutrition (Mini Nutritional Assessment) were examined. @*Results@#After the program, all subjects displayed significantly increased nutrient intake.Before the intervention, all subjects were in a state of food insecurity; however, after the intervention, 37.1% of the subjects were food secure. Moreover, the rates of being at risk of malnutrition and malnutrition in subjects were decreased and instead rate of those who improved to normal increased to 29.8% from 0% of normal rate before the prevention. The rate of subjects without anemia increased from 18.7% to 28.5% after the intervention. In addition, the rate of subjects with intensive or periodic management of chronic diseases decreased, while those with occasional management of chronic diseases increased from 0% to 4.6%. Furthermore, the rates of being at risk of frailty and frailty were decreased and the normal rate increased from 0% to 9.7% instead. Age group-based analysis showed that elderly people over 80 years showed less improvement in the management of the chronic disease status and the frailty status. @*Conclusion@#Personalized supplementary food supplies and nutritional education improved not only the nutritional status but also disease status in vulnerable older adults, and the effects were more significant in adults aged less than 80 years.