BACKGROUND: The present study aims to examine the reliability and validity of a Korean version of the CAMCOG-R(CAMCOG-RK) in a clinical setting and an institution, that have been widely used to detect early dementia. METHODS: Study participants included 243 dementia sufferers, 68 mild cognitive impairment(MCI) suffers and 354 non-demented subjects. DSM-IV clinical criteria for dementia and Petersen's criteria for MCI were used as the 'gold' standards. The CAMCOG-R was translated into Korean and then back to English. Six items needed modifications for local usage. RESULTS: Interrater and test-retest scores calculated as intraclass correlation coefficients showed excel- lent for total score and all subscale scores of CAMCOG-RK. A strong concurrent validity was found with the MMSE-K score(r=0.82, p<0.01). Examination of the association between CAMCOG-R scores and socio- demographic variables(age, sex, and education) shows that age and education exerts a significant, and independent, effect upon performance. The eight age and education-specific cutoff point for dementia and MCI provided excellent sensitivity and specificity mostly more than 90%. CONCLUSION: The CAMCOG-RK was found to be an appropriate instrument to discriminate between demented and non-demented individuals and between individuals with MCI and without MCI in a clinical setting. Further studies should examine the psychometric characteristics of the CAMCOG-RK in a more varied sample.
Dementia* ; Diagnosis* ; Diagnostic and Statistical Manual of Mental Disorders ; Education ; Korea ; Psychometrics ; Reproducibility of Results ; Sensitivity and Specificity

The use of pure titanium and titanium alloys have been increased recently in fixed, removable prosthodontics and implant fields as a framework. But when they were used for superstructures of implant of metal framework of removable prosthesis, welding is necessary to reconnect the fracture site to control the casting distortions. To overcome the difficulties in soldering the titanium due to high oxidation property, much effort have been devoted. In this study, some of mechanical properties were compared between pure titanium and Ti-6Al-4V alloy by usingl aser welding, electron beam welding technique and tungsten arc welding. Mechanical properties such as tensile strength, yield strength, elongation and microhardness were measured. And, in order to compare the effect of welding site and surrounding metal tissue according to the welding condition, SEM photographs were taken an element distribution was observed by Wave Dispersion Spectroscopy. Through analyses of the data, following results were obtained; 1. In items such as tensile strength, yield strength and elongation according to the welding techniques of pure titanium, only tungsten arc welded group showed significant lower value than other groups(P<0.05). 2. In items such as tensile strength and yield strength according to the welding techniques of Ti-6Al-4V alloy, control group and tungsten arc welded group showed significant difference among all the groups(P<0.05). 3. Ti-6Al-4V alloy exhibited significantly greater elongation than control group when the laser welding method and electron beam welding method were used, and elongation showed increasing tendency. 4. Pure titanium specimens exhibited increasing tendency of microhardness regardless of the welding technique applied, and especially tungsten arc welded group demonstrated a great increase of microhardness than parent metal. 5. There was no hardness change in laser welded group and electron bean welded group of Ti-6Al-4V ally, but in tungsten arc welded group, hardness changed greatly from parent metal to weld seam. 6. Through the metallographic examination and scanning electron microscopy, laser welding caused central fusion and recristallizations were formed and tungsten arc welding caused localized fusion to 0.3-0.7mm from the surface.
Alloys ; Hardness ; Humans ; Microscopy, Electron, Scanning ; Parents ; Prostheses and Implants ; Prosthodontics ; Spectrum Analysis ; Tensile Strength ; Titanium* ; Tungsten ; Welding*

To elucidate the effects of food texture such as hardness, cohesiveness, adhesiveness on mastication procedure, the electromyographic activity (EMG) of the masticatory muscles and the chewing movements were analyzed in eighteen young subjects during ordinary chewing. Seven different foods were selected by sensory texture profiling and mechanical test with texturometer; egg white, sausage, pizza cheese, yang-geng, biscuit, peanut and almond. The indexes of jaw movements used were the chewing number, chewing time, maximum opening, average opening, closing velocity and opening velocity. The EMG indexes analyzed were maximum and average integrated amplitude of the anterior temporal and masseter muscles. The results obtained were as follows. 1. The chewing time and chewing number, mandibular displacement and mandibular movement velocity were not changed by the hardness, cohesiveness and adhesiveness of the food (p>0.05). 2. The harder food materials showed a higher amplitude of the anterior temporal muscle integrated EMGs than the softer ones (p<0.05). 3. The maximum and average integrated EMGs of the masseter muscle increased with the increase of hardness of the food (p<0.05). 4. The integrated EMGs of preferred side and non-preferred side masticatory muscles increased with the increase of hardness of the food (p<0.05). 5. The adhesiveness and cohesiveness of the food were not the determining factor to the integrated EMGs of masticatory muscles (p<0.05).
Adhesiveness ; Cheese ; Egg White ; Hardness ; Jaw ; Masseter Muscle ; Mastication* ; Masticatory Muscles* ; Prunus dulcis ; Temporal Muscle

The purpose of this study was to compare and evaluate the stress distribution and displacement developed in the abutment teeth and residual ridge area by madibular unilateral distal extension removable partial denture with 2 different retainer designs. The retainers on right and left canine and right 2nd molar were Akers clasp in one model and telescopic crown in the other model. The stress distribution of abutment teeth and residual ridge area on two model were compared and analyzed with 3-dimensional finite element method. 150N and 400N forces were applied vertically, 30 degree and horizontally on the central fossa area of left 1st molar of the removable partial denture, and then stress distribution patterns were analyzed and compared. The results were as follows 1. As the magnitude and angulation of applied force were increased, the magnitude of stress on the right and central residual ridge area and the right canine of the telescopic type increased and comparing to those of the Akers clasp type. 2. As the magnitude and angulation of applied force were increased, the mesial direction of displacement on the right residual ridge area and the right tooth of the telescopic type increased and the distal direction of displacement on left residual ridge area and the left canine increased comparing to those of Akers clasp type. 3. As the vertical force was applied, the distal direction of the displacement of the right tooth were greater and that of the left canine was smaller and the upward displacement of the right canine was greater in telescopic partial denture than those of Akers clasp type. 4. As the 30 degree force was applied, the mesial direction of the displacement of the right tooth were greater and the distal direction of the displacement of the left canine was smaller and the upward displacement of the right canine was greater in telescopic partial denture than those of Akers clasp type. In the horizontal force the results were same in right area tooth but the distal direction of displacement was greater in left canine. 5. In both removable partial dentures, as the magnitude and degree of force were increased, the stress and displacement were increased. The compressive force was dominative than the tensile force. 6. In both removable partial dentures, the magnitude of stress was greater on mucosal tissue area than that of the alveolar bone area on distal extension residual ridge area but the result was reversed on anterior residual ridge area. The displacement was always greater on mucosal tissue area than that of alveolar bone area.
Crowns ; Denture, Partial ; Denture, Partial, Removable ; Molar ; Mucous Membrane ; Tooth*

Dexamethasone is a widely used anti-inflammatory agent for a broad spectrum of diseases. The effectiveness of this agent is thought to be due to the capacity to modulate cytokine production in inflammatory cells. We examined the effects of dexamethasone on expressions of interferon gamma (IFN-gamma) and interleukin 4 (IL-4) by human peripheral blood mononuclear cells (PBMCs) in response to interleukin 12 (IL-12). Dexamethasone (10-5 M) inhibited IFN-gamma secretion, through direct suppression of IFN-gamma, IL-12 receptor (IL-12R) -beta1, and -beta2 expressions. Conversely dexamethasone increased IL-4 secretion as well as IL-4 expressions by PBMCs in response to IL-12. In addition, dexamethasone increased expression of suppressor of cytokine signalling (SOCS)-1, which inhibits JAK-STAT pathway of IL-12R signalling. The result of our study suggested that dexamethasone directly inhibited IFN-gamma expression, through suppression of IL-12 signalling and indirectly increases IL-4 expression, through suppression of IFN-gamma expression.
Dexamethasone* ; Humans ; Interferons ; Interleukin-12* ; Interleukin-4* ; Receptors, Interleukin-12

The color stability of current prosthetic composites is unknown, even though the quality of com-posite materials has been improving. This study examined the intrinsic color stability of various current prosthetic resins (ceramic-polymers) after an accelerated aging process and the extrinsic color stability after immersion in a coffee solution. By comparing the amount of dis-coloration after aging with that without aging, the effect of the accelerated aging process on external discoloration could be evaluated. Three current prosthetic composites (Artglass, Targis, Sculpture), one light polymerized direct composite (Z100) and one dental porcelain control (Ceramco) were assessed. The col-or changes (delta E) of all the specimens were determined using the CIE L*a*b* color order system with a reflected spectrophotometer. The results were as follows: 1. The prosthetic composite materials subjected to the accelerated aging test showed no sig-nificant difference in color changes (p> .05). 2. In the coffee solution immersion test after the aging process, the color changes of the Targis and Artglass groups were not different from that of the Z100 group, which showed the highest color change. 3. In the immersion only test, a significantly high color change was observed in the sculpture glazing group. 4. The aging process influenced on the color changes more in the Targis, Artglass and Z100 groups than in the Sculpture and Ceramco groups.
Aging* ; Coffee* ; Dental Porcelain ; Immersion* ; Polymers ; Sculpture

The purpose of this study was to investigate the cytotoxicity and mutagenicity of denture ase resins. According to manufacturer's instructions, resin specimens were made. Group 1: heat-polymerizing acrylic resin (Luciton 199(R)). Group 2: heat-polymerizing acrylic resin containing polyhedraloligosilsesquioxane(POSS esin). Group 3: auto-polymerizing acrylic resin (Repair Acrylic(R)). Group 4: direct relining auto-polymerizing acrylic resin (Tokuso Rebase(R)). Fresh specimens, 24 hrs. and 72 hrs. soaked specimens in distilled water were made. Responses with metabolic assay and mutagenesis assay to eluates from resin specimens were measured. Cultures with medium alone provided controls. Cytotoxicity was assessed with agar overlay test. The results were as follows: 1. Group 4 showed higher cytotoxicity than Group 1, Group 2 and Group 3 in fresh, 24-and 72-hour immersion cases (p<.05). Group 3 showed higher cytotoxicity than Group 2 in fresh cases and showed higher cytotoxicity than Group 1 and Group 2 in 24-and 72-hour immersion cases (p<.05). Group 1 and Group 2 showed no significant difference. 2. All acrylic denture base resins showed significant increase of cell activity as immersion time increased (p<.05). 3. Auto-polymerizing acrylic denture base resins showed higher cytotoxicity than heat-polymerizing acrylic denture base resins (p<.05). 4. All acrylic denture base resins showed lower mutagenicity than controls (p<.05).
Agar ; Denture Bases* ; Dentures* ; Immersion ; Mutagenesis ; Water

STATEMENT OF PROBLEM: In the partially edentulous patients, removable partial dentures have been working as a important treatment modality. Clasps, a kind of direct retainers, received some amount of stresses during the insertion and removal of partial denture on the abutment tooth. PURPOSE: The study is to investigate stresses of the different clasps. MATERIAL AND METHODS: In order to investigate the degree of stresses, maxillary partial edentulism (Kennedy Class II, modification 1) was assumed and removable partial dentures were designed on it with three kinds of metallic materials; cobalt-chromium alloy, type IV gold alloy and commercially pure (c.p.) titanium. Aker's clasp was applied on the left second molar, RPA (mesial rest-proximal plate-Aker's) clasp was on the left first premolar and wrought wire clasp was on the right first premolar. Three dimensional, non-linear, dynamic finite element analysis method was run to solve this process. RESULTS: 1. Cobalt-chromium alloy had the highest von Mises stress value and c.p. titanium had the lowest one irrespective of the types of clasps. 2. In the Aker's clasps, stress on the retentive tips was shown shortly after the appearance of stresses of the middle and minor connector areas. These time lag was much shorter in the RPA clasps than in the Aker's clasp. 3. In general, retentive tips of wrought wire clasps had much less amount of stress than other clasps. CONCLUSION: The amount of stress was the highest in the RPA clasp and the lowest in the wrought wire clasp, in general.
Alloys ; Bicuspid ; Denture, Partial ; Denture, Partial, Removable* ; Finite Element Analysis ; Humans ; Molar ; Titanium ; Tooth

STATEMENT OF PROBLEM: Unreasonable distal cantilevered implant-supported prosthesis can mask functional problems of reconstruction temporarily, but it can cause serious strain and stress around its supported implant and surrounding alveolar bone. PURPOSE: The purpose of this study was to evaluate strain of implants supporting distal cantilevered fixed prosthesis with two different cantilevered length under distal cantilevered static load. MATERIAL AND METHODS: A partially edentulous mandibular test model was fabricated with auto-polymerizing resin (POLYUROCK; Metalor technologies, Stuttgart, Swiss) and artificial denture teeth (Endura; Shofu inc., Kyoto, Japan). Two implants-supported 5-unit screwretained cantilevered fixed prosthesis was made using standard methods with Type III gold alloy (Harmony C & B55; Ivoclar-vivadent, Liechtenstein, Germany) for superstructure and reinforced hard resin (Tescera; Ivoclar-vivadent, Liechtenstein, Germany) for occlusal material. Two strain gauges (KFG-1-120-C1-11L1M2R; KYOWA electronic instruments, Tokyo, Japan) were then attached to the mesial and the distal surface of each standard abutment with adhesive (M-bond 200; Tokuyama, Tokyo, Japan). Total four strain gauges were attached to test model and connected to dynamic signal conditioning strain amplifier (CTA1000; Curiotech inc., Paju, Korea). The stepped 20-100 N in 25 N increments, cantilevered static load 8mm apart (Group I) or 16mm apart (Group II), were applied using digital push-pull gauge (Push-Pull Scale & Digital Force Gauge, Axis inc., Seoul, Korea). Each step was performed ten times and every strain signal was monitored and recorded. RESULTS: In case of Group I, the strain values were surveyed by 80.7 ~ 353.8 micrometer/m in Ch1, 7.5 ~ 47.9 micrometer/m in Ch2, 45.7 ~ 278.6 micrometer/m in Ch3 and -212.2 ~ -718.7 micrometer/m in Ch4 depending on increasing cantilevered static load. On the other hand, the strain values of Group II were surveyed by 149.9 ~ 612.8 micrometer/m in Ch1, 26.0 ~ 168.5 micrometer/m in Ch2, 114.3 ~ 632.3 micrometer/m in Ch3, and -323.2 ~ -894.7 micrometer/m in Ch4. CONCLUSION: A comparative statistical analysis using paired sample t-test about Group I Vs Group II under distal cantilevered load shows that there are statistical significant differences for all 4 channels (P<0.05).
Adhesives ; Alloys ; Axis, Cervical Vertebra ; Dentures ; Hand ; Liechtenstein ; Masks ; Prostheses and Implants* ; Seoul ; Tooth

PURPOSE: The aim of this study was to investigate a comparison of implant bone bed preparation with Er,Cr:YSGG laser and conventional drills on the relationship between implant stability quotient (ISQ) values and implant insertion variables. MATERIALS AND METHODS: Forty implants were inserted into two different types of pig rib bone. One group was prepared with conventional drills and a total of 20 implants were inserted into type I and type II bone. The other group was prepared with a Er,Cr:YSGG laser and a total of 20 implants were inserted into type I and type II bone. ISQ, maximum insertion torque, angular momentum, and insertion torque energy values were measured. RESULTS: The mean values for variables were significantly higher in type I bone than in type II bone (P < .01). In type I bone, the ISQ values in the drill group were significantly higher than in the laser group (P < .05). In type II bone, the ISQ values in the laser group were significantly higher than in the drill group (P < .01). In both type I and type II bone, the maximum insertion torque, total energy, and total angular momentum values between the drill and laser groups did not differ significantly (P > or = .05). The ISQ values were correlated with maximum insertion torque (P < .01, r = .731), total energy (P < .01, r = .696), and angular momentum (P < .01, r = .696). CONCLUSION: Within the limitations of this study, the effects of bone bed preparation with Er,Cr:YSGG laser on the relationship between implant stability quotient (ISQ) values and implant insertion variables were comparable to those of drilling.
Mandrillus ; Ribs ; Salicylates ; Torque