The computer-aided design/computer-aided manufacturing (CAD/CAM) system was introduced to shorten the production time of all-ceramic restorations and the number of patient visits. Among these types of ceramic for dental CAD/CAM, they have been processed into inlay, onlay, and crown shapes using leucite-reinforced glass-ceramics to improve strength. The purpose of this study was to observe the mechanical properties and microstructure of leucite-reinforced glass-ceramics for dental CAD/CAM. Two types of leucite-reinforced glass-ceramic blocks (IPS Empress CAD, Rosetta BM) were prepared with diameter of 13 mm and thickness of 1 mm. Biaxial flexural testing was conducted using a piston-on-three-ball method at a crosshead speed of 0.5 mm/min. Weibull statistics were used for the analysis of biaxial flexural strength. Fracture toughness was obtained using an indentation fracture method. Specimens were observed by field emission scanning electron microscopy to examine the microstructure of the leucite crystalline phase after acid etching with 0.5% hydrofluoric acid aqueous solution for 1 minute. The results of strength testing showed that IPS Empress CAD had a mean value of 158.1±8.6 MPa and Rosetta BM of 172.3±8.3 MPa. The fracture toughness results showed that IPS Empress CAD had a mean value of 1.28±0.19 MPa·m(1/2) and Rosetta BM of 1.38±0.12 MPa·m(1/2). The Rosetta BM sample exhibited higher strength and fracture toughness. Moreover, the crystalline phase size and ratio were increased in the Rosetta BM sample. The above results are expected to elucidate the basic mechanical properties and crystal structure characteristics of IPS Empress CAD and Rosetta BM. Additionally, they will help develop leucite-reinforced glass-ceramic materials for CAD/CAM.
Ceramics ; Crowns ; Crystallins ; Humans ; Hydrofluoric Acid ; Inlays ; Methods ; Microscopy, Electron, Scanning

The aim of this study was to compare fluoride release and surface changes according to different orthodontic bracket adhesives the application of fluoride products. We used non-fluoridated composite resin Transbond fluoridated composite resins Blugloo and LightBond, resin-modified glass ionomer Rely XTM Luting 2, and conventional glass ionomer Fuji I®. Fluoride release of five orthodontic bracket adhesives and fluoride release ability after application of three fluoride products (1.23% acidulated phosphate fluoride gel, Tooth Mousse Plus®, Fluor Protector, and a toothbrush with sodium fluoride-containing toothpaste) were measured using a fluoride electrode that was connected to an ion analyzer. After 4 weeks of fluoride application, the surface roughness and surface morphology were examined using a surface roughness tester and field emission scanning electron microscopy. The amounts of fluoride release were observed not only on application of Tooth Mousse Plus® and Fluor Protector on resin-modified glass ionomer Rely XTM Luting 2 and Fuji I®, but also during tooth brushing using fluoride-containing toothpaste. After application of Tooth Mousse Plus®, except Transbond XT, the surface roughness increased, and all orthodontic adhesives showed a partial drop of micro-particle filler. On application of 1.23% acidulated phosphate fluoride gel on all orthodontic bracket adhesives, their surface roughness increased. To bond the orthodontic bracket, resin-modified glass ionomer Rely XTM Luting 2 and Fuji I® adhesives are highly recommended if the amount of fluoride release is considered to confer a preventative effect on dental caries, and among the fluoride products, Tooth Mousse Plus® and Fluor Protector are better than 1.23% acidulated phosphate fluoride gel, and these are expected to prevent dental caries even during tooth brushing with fluoride-containing toothpaste.
Acidulated Phosphate Fluoride ; Adhesives* ; Composite Resins ; Dental Caries ; Dental Cements ; Electrodes ; Fluorides* ; Glass ; Microscopy, Electron, Scanning ; Orthodontic Brackets* ; Sodium ; Surface Properties* ; Tooth ; Toothpastes

BACKGROUND: Although adult immunization is as important as childhood immunization, is being inadequately performed. However, previous studies concerning adult immunization could not be sufficiently evaluate because studies were restricted to the residents in rural area or those who have visited a doctor. METHOD: We conducted a study by telephone interview which included 201 household(375 adult family members) selected by systematic sampling from the yellow pages of Kangnam-gu and Sungbuk-gu districts of Seoul. The types of immunization covered in this study were immunizations against hepatitis B, influenza, pneumococcus, and hemorrhagic fever with renal syndrome(HFRS). Immunization status of all adult household members, cognition of the feed for immunization and of interviewees were surveyed. Sex, age, area of residency, education medical history of study subjects were considered as factors related to the cognition of the need for immunization and immunization performance. RESULT: The cognition rates of immunization were as follows: hepatitis B 85.1%, influenza 45.8% pneumonra 38.3%, and HFRS 38.3%. In the people over 65 years old, the cognition rate against influenza and pneumococeus were 6.25%, 6.25% respectively and for those she have chronic disease.80.0%, 20.0%, respectively. The cognition rates of immunization was significantly higher among those subject who were young, well educated, and those residing in Kangnam-gu district. The immunization performance rate of hepatitis B was 6.5%, influenza 5.6%, pneumonia 0.8%, and HFRS 1.1%. 75.5% of subjects vaccinated against hepatitis B had received at least three titles. The immunization performance rate of influenza and pneumococcus by the immunization indication are as follows 8.0%, 0.0%, respectively in the subjects over 65 years old, and 11.1%, 0.0,% respectively in the people who have chronic disease. The immunization performance rate of hepatitis B was higher among young, well educated subjects living in Kangnam-gu district. But age, education, area of residency played no apparent role in the case of other types of immunization. The immunization performance rate of those who felt the need for immunization as significant1y higher then that of those who did not. To assess the factors which re]ate to the correct cognition for immunization necessity, we used a multiple logistic regression test. For all types of immunization surveyed, sex(femals) and age (young) seemed to be significantly related to the correct necessity cognition. Medical history of chronic disease was also related to the correct necessity cognition for immunization against hepatitis B and influenza. CONCLUSION: This study reveals that among living in urban area the immunization performance rate and the correct cognition rate concerning the necessity for adult immunization was generally very low. Therefore, an active publicity and pubic education will be needed to increase the level of correct necessity cognition for immunization in which the disease status, sex, and age of vaccinee are considered. And more active effort to increase the cognition for immunization necessity performance is required.
Adult* ; Aged ; Chronic Disease ; Cognition* ; Education ; Family Characteristics ; Fever ; Hemorrhagic Fever with Renal Syndrome ; Hepatitis B ; Humans ; Immunization* ; Influenza, Human ; Internship and Residency ; Interviews as Topic ; Logistic Models ; Pneumonia ; Seoul ; Streptococcus pneumoniae

In this study, clinically applicable methods of improving the bond strength between Y-TZP and the bracket were considered, which the method was confirmed for the durability in a humid oral environment. The bond strength of Y-TZP bonding surface and the surface characteristics were analyzed following the surface treatment of Y-TZP specimens with conditioning by 30 μm tribochemical silica coating, or tribochemical silica coating with one of the following primers: silane, MDP, or an MDP-containing silane primer. It was found that after surface treatment, the surface roughness of all groups increased (p<0.05), and Si was uniformly distributed on the Y-TZP surface after silica coating. The bond strength value of the group treated with silane primer and tribochemical coating was not significantly different after thermocycling (p>0.05). The group treated with MDP primer and tribochemical silica coating showed a significant difference in bond strength values after thermocycling (p<0.05), and it showed the lowest bond strength values except the untreated groups (p<0.05). The group treated with tribochemical silica coating and MDP-containing silane primer showed the highest bond strength values (p<0.05), and was not significantly different after thermocycling (p>0.05). Therefore, the surface treatments of Y-TZP with MDP-containing silane primer after 30 μm tribochemical silica coating enhanced the bond strength to the orthodontic metal bracket; such a clinically applicable method may advance studies on the surface treatment of Y-TZP.

Objective: This study evaluated the effect of cyclic pre-calcification treatment on the improvement of bioactivity and osseointegration of Ti-6Al-4V miniscrews. Methods: The experimental groups were: an untreated group (UT), an anodized and heat-treated group (AH), and an anodized treatment followed by cyclic pre-calcification treatment group (ASPH). A bioactive material with calcium phosphate was coated on the mini-screws, and its effects on bioactivity and osseointegration were evaluated in in vitro and in vivo tests of following implantation in the rat tibia. Results: As a result of immersing the ASPH group in simulated body fluid for 2 days, protrusions appearing in the initial stage of hydroxyapatite precipitation were observed. On the 3rd day, the protrusions became denser, other protrusions overlapped and grew on it, and the calcium and phosphorus concentrations increased. The removal torque values increased significantly in the following order: UT group (2.08 ± 0.67 N·cm), AH group (4.10 ± 0.72 N·cm), and ASPH group (6.58 ± 0.66 N·cm) with the ASPH group showing the highest value (p < 0.05). In the ASPH group, new bone was observed that was connected to the threads, and it was confirmed that a bony bridge connected to the adjacent bone was formed. Conclusions In conclusion, it was found that the surface treatment method used in the ASPH group improved the bioactivity and osseointegration of Ti-6Al-4V orthodontic miniscrews.

The purpose of this study was to observe the surface morphology and roughness of micro-hybrid and nano-filled resin composites and compare wear resistance by conducting a toothbrushing wear test with toothpastes with different abrasive ingredients. Two types of resin composites containing micro-hybrid fillers (Z100 Restorative, Filtek Z250) and one type of resin composite containing nanofillers (Filtek Z350 XT) were used. For the toothbrushing wear test, 90 resin composite samples with a diameter of 10 mm and a thickness of 1 mm were prepared. A force of 2 N and 100,000 cycles of brushing were performed using a pin-on-disk wear tester. The toothpastes used in the test were classified into 4 groups according to the abrasive ingredients (hydroxyapatite, calcium carbonate, sodium bicarbonate, and zeolite-M). After the toothbrushing wear test, the surface morphology of the samples was observed using an optical microscope and a scanning electron microscope (SEM), and the surface roughness was measured using atomic force microscopy (AFM). Relatively large filler particles (micro size) protruded from the surface of the micro-hybrid resin composite groups, and small crater-shaped defects were observed. The surface roughness values of the groups that performed the wear test with toothpaste containing zeolite-M were significantly higher than the other groups (P<0.05). The surface roughness value was significantly (P<0.05) highest in the group where the nanofilled resin composite was wear-tested with toothpaste containing zeolite-M. However, regardless of the type of toothpaste, the surface roughness showed low values of less than 0.1 μm. The surface appeared uniform and smooth compared to the surface of micro-hybrid resin composites. Finally, the nano-filled resin composite showed relatively higher wear resistance than the micro-hybrid resin composite. This means that wear resistance during brushing may indicate the durability of the material in the clinic.

OBJECTIVES: The purpose of this study was to assess the effect of single and combined applications of fluoride on the amount of fluoride release, and the remineralization and physical properties of enamel. MATERIALS AND METHODS: Each of four fluoride varnish and gel products (Fluor Protector, FP, Ivoclar Vivadent; Tooth Mousse Plus, TM, GC; 60 Second Gel, A, Germiphene; CavityShield, CS, 3M ESPE) and two fluoride solutions (2% sodium fluoride, N; 8% tin(ii) fluoride, S) were applied on bovine teeth using single and combined methods (10 per group), and then the amount of fluoride release was measured for 4 wk. The electron probe microanalysis and the Vickers microhardness measurements were conducted to assess the effect of fluoride application on the surface properties of bovine teeth. RESULTS: The amount of fluoride release was higher in combined applications than in single application (p < 0.05). Microhardness values were higher after combined applications of N with FP, TM, and CS than single application of them, and these values were also higher after combined applications of S than single application of A (p < 0.05). Ca and P values were higher in combined applications of N with TM and CS than single application of them (p < 0.05). They were also increased after combined applications of the S with A than after single application (p < 0.05). CONCLUSIONS: Combined applications of fluoride could be used as a basis to design more effective methods of fluoride application to provide enhanced remineralization.
Dental Caries ; Dental Enamel ; Electron Probe Microanalysis ; Fluorides* ; Methods* ; Paint ; Sodium Fluoride ; Surface Properties ; Tooth

BACKGROUND/AIMS: Immediate postpolypectomy bleeding (IPPB) increases the procedure time and it may disturb performing a safe polypectomy. The purpose of this study is to investigate whether clipping before snare polypectomy of large pedunculated polyps is useful for the prevention of IPPB. METHODS: This is a single arm, pilot study. We enrolled patients with pedunculated colorectal polyps that were 1 cm in size or more from 4 university hospitals between June 2009 and June 2010. Clips were applied at the stalk and snare polypectomy was then performed. The complications, including IPPB, were investigated. RESULTS: Fifty six pedunculated polyps in 47 patients (Male:Female=36:11; age, 56+/-11 years) were included. The size of the polyp heads was 17+/-8 mm. Tubular adenoma was most common (57%). The number of clips used before snare polypectomy was 2+/-0.5. The procedure was successful in all cases. IPPB occurred in 2 cases (3.6%), and both of these were managed by additional clipping. Delayed bleeding occurred in another one case (1.8%), which improved with conservative treatment. No perforation occurred. CONCLUSIONS: We suggest that clipping before snare polypectomy of pedunculated polyps may be an easy and effective technique for the prevention of IPPB, and this should be confirmed in large scale, prospective, controlled studies.
Adenoma ; Arm ; Head ; Hemorrhage ; Hospitals, University ; Humans ; Intermittent Positive-Pressure Breathing ; Pilot Projects ; Polyps ; SNARE Proteins

Titanium mesh is commonly employed to reinforce missing alveolar ridges and promote bone regeneration around implants. However, the bioinertness of titanium mesh must be improved. This study evaluated the effect of improving bioactivity and bone regeneration by loading a calcium phosphate coating layer and ibandronate onto a titanium mesh with a nanotube-structured TiO2 layer. The surface treatment of titanium mesh was divided into four groups: (1) No treatment; (2) Formation of nanotube TiO2 layer; (3) Cyclic calcification pretreatment (calcium phosphate coating layer) after the formation of a nanotube TiO2 layer; (4) Calcium phosphate coating and ibandronate loading after the formation of a nanotube TiO2 layer. The release amount of ibandronate was analyzed using a UV spectrophotometer, and bioactivity was assessed through XRD, EDS, and HR FE-SEM to observe changes in the surface layer after immersion in simulated body fluid (SBF). Hydroxyapatite was uniformly distributed on the surface of the (4) group immersed in SBF, and calcium and phosphorus content also increased over time. This result supported that bioactivity was improved. The continuous release of ibandronate over 10 days may contribute to realizing a mechanism that improves osseointegration between bone and titanium mesh. These results showed that bioactivity was improved as calcium phosphate precipitated on the surface of the nanostructured titanium mesh. Additionally, it is believed that combined ibandronate can effectively increase the stability of titanium mesh and promote bone regeneration.

Prosthodontic treatment is being performed for morphology and functional restoration due to damage and loss of teeth. As the aesthetic demands of patients increase, interest in ceramic materials with shades and translucency similar to natural teeth has increased.Recently, the manufacturing and processing technology of ceramic materials has greatly improved, and the market for dental ceramic materials is growing rapidly. The purpose of this literature review and evaluation is to provide information on the classification and properties of dental ceramic materials with excellent aesthetics and fracture resistance. In this article, it is classified as follows: I) Dental porcelain; II) Sinterable all-ceramic; III) Glass-ceramic for casting; IV) Glass-infiltrated alumina ceramic; V) Glass-ceramic ingots for heat-pressing technique; Vl) Blocks for CAD/CAM; Vll) Ceramic for CAD/3D printing. Dental ceramic materials and their restoration manufacturing methods have evolved significantly over the past decade. As a result, the manufacturing method of restorations has progressed from the layered firing technique of powdered materials or heat-pressing technique to the cutting and processing of single and multi-layer blocks using CAD/CAM technology, leading to the introduction of CAD/3D printing technology. In this manuscript, we will review the types of ceramic materials used in the fabrication of dental restorations and their advantages and disadvantages.