PURPOSE: The aim of the present study was to assess the effect of ascorbic acid, ethanol and acetone on microtensile bond strength between fiber posts pre-treated with hydrogen peroxide and composite resin cores. MATERIALS AND METHODS: Twenty four fiber posts were pre-treated with 24% hydrogen peroxide and divided into 4 groups as follows: G1: no treatment, as control group; G2: treatment with 10% ascorbic acid solution for 5 minutes; G3: treatment with 70% ethanol solution for 5 minutes; and G4: treatment with 70% acetone solution for 5 minutes. Each fiber post was surrounded by a cylinder-shaped polyglass matrix which was subsequently filled with composite resin. Two sections from each sample were selected for microtensile test at a crosshead with speed of 0.5 mm/min. Statistical analyses were performed using one-way ANOVA and a post hoc Tukey HSD test. Fractured surfaces were observed under a stereomicroscope at x20 magnification. The fractured surfaces of the specimens were observed and evaluated under a SEM. RESULTS: Means of microtensile bond strength values (MPa) and standard deviations in the groups were as follows: G1: 9.70+/-0.81; G2: 12.62+/-1.80; G3: 16.60+/-1.93; and G4: 21.24+/-1.95. G4 and G1 had the highest and the lowest bond strength values, respectively. A greater bond strength value was seen in G3 compared to G2. There were significant differences between all the groups (P<.001). All the failures were of the adhesive mode. CONCLUSION: Application of antioxidant agents may increase microtensile bond strength between fiber posts treated with hydrogen peroxide and composite cores. Acetone increased bond strength more than ascorbic acid and ethanol.
Acetone ; Adhesives ; Ascorbic Acid ; Ethanol ; Hydrogen Peroxide

Warts are benign turnors caused by oncogenic human papovavirus which has been clearly identified on electronmicroscopy, although repeated atternpts at culture have not been successful. Various therapeutic modalities have been tried for the treatment of warts, however thete is no saisfactory method and the clinical course as well as the prognosis is always variable. Recently several authors have reported successful therapeutic results in the treatment of warts by DNCB sensitization method based on the findings that warts are often regressing spontaneously and that the spontaneous regression seems to depend on host's ability to mount an immune response against the wert virus. The present study was undertaken to evaluate the DNCB sensitization method for possible routine use in the treatment of warts. Fifteen cases including five verruca vulgaris and ten verruca plana juvenilis patients were sensitized with 1000ug of DNCB in acetone solution on either side of their inner forearms. Seven or ten days after sensitization, several warts, which were unintentionally selected, were challenged with 0.05 to 0.1ml of weaker DNCB solution(50ug-25ug/0.1ml)at weekly interval. Four patients with verruca vulgaris and three patients with verruca plana juvenilis did not return after 1 to 4 times of challenge, however six out of these 7 patients showed a slight decrease in size and number of the warts. One patient with verruca plana juvenilis developed marked irritative and delayed cutaneous hypersensitivity reaction to the 3 times of challenge, so that this patient was excluded from further study. The remaining 7 patients consisted of I verruca vulgaris and 6 verruca plana juvenilis patients showed complete disappearance of all warts including those which were never challenged, after 1 to 13 times of DNCB challenge application. The authors reviewed the possible therapeutic mechanism of DNCB sensitization in the wart patients, the possible advantage and disadvantage of this method and concluded that this method can be cautiously used in seleted patients with warts whose response to the conventional treatment methods are poor.
Acetone ; Dinitrochlorobenzene* ; Forearm ; Humans ; Hypersensitivity ; Prognosis ; Warts*

PURPOSE: To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS: A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non-quantitatively. RESULTS: All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION: The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.
Acetone ; Ceramics ; Ethanol ; Spectrum Analysis ; Steam ; Ultrasonics

PURPOSE: To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS: A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non-quantitatively. RESULTS: All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION: The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.
Acetone ; Ceramics ; Ethanol ; Spectrum Analysis ; Steam ; Ultrasonics

BACKGROUND: In eczematous skin it is expected that altered defense mechanisms are employed against an injury, which mechanisms include alterations in the stratum corneum barrier function and lipid contents. OBJECTIVE: To investigaten aspect of pathophysiology of hand eczema by comparing the water holding capacities and transepidermal water loss(TEWL) after injuries on the skin and by comparing the epidermal lipid contents between hand eczema and normal subjects. METHODS: The water holding capacities were checked by corneometer, and the TEWL were checked after epidermal barrie! destruction with acetone or adhesive tapes. The epidermal lipids were extracted with acetone, ther (1: 1 v/v) mixture solvent and analysed by HP- TLC. RESULTS: The water holdingapacities were decreased in eczema of the palm, but the recoveries of TEWL and the lipid content did not differ between hand eczema and normal subjects. CONCLUSION: The water holding capacities were decreased in the eczematous skin. But there were no significant differencies in the recovery of destructed epidermal barrier and the epidermal lipid contents.
Acetone ; Adhesives ; Defense Mechanisms ; Eczema* ; Hand* ; Skin ; Water

STATEMENT OF PROBLEM: The failure of adhesion between the resilient denture liner and the denture base is a serious problem in clinic. PURPOSE: The PURPOSE of this study was to evaluate the effect of denture base resin surface pretreatments (mechanical and/or chemical) on the tensile bond strength between a resilient liner and processed denture resin. MATERIAL AND METHOD: Acrylic-based resilient liners (Soft liner; GC co., Japan & Coe-Soft; GC America Inc. USA) and silicone-based resilient liners (Mucosoft; Parkell Inc., USA & Dentusil; Bosworth co., USA) were used. Specimens in each soft lining material were divided two groups with or without mechanical pretreatment. Each denture base specimen received 1 of 4 chemical pretreatments including: (1) no treatment, (2) 30-s acetone treatment, (3) 15-s methylene chloride treatment, (4) 180-s methyl methacrylate treatment. All specimens were thermocycled and placed under tension until failure in a universal testing machine. RESULTS: 1. Silicone-based resilient liners exhibited significantly higher tensile bond strengths than acrylicbased resilient liners (P<.05). 2. Grinding the denture base resin improved tensile bond strengths of silicone-based resilient liners, but reduced tensile bond strengths of acrylic-based resilient liners (P<.05). 3. In acrylic-based resilient liners, treating with acetone significantly increased the bond strength of Soft liner and treating with methyl methacrylate significantly increased the bond strength of Coe-Soft (P<.05). However they were not effective compared to silicone-based resilient liner. 4. In silicone-based resilient liners, treating with all chemical etchants significantly increased the bond strength of Mucosoft to denture base, and treating with methylene chloride and methyl methacrylate increased the bond strength of Dentusil to denture base (P<.05). CONCLUSION: Although chemical and mechanical pretreatments were not effective on tensile bond strength of acrylic-based resilent liner to denture base, treating the denture base resin surface with appropriate chemical etchants after mechanical pretreatment significantly increased the tensile bond strength of silicone-based resilient liner to denture base.
Acetone ; Americas ; Denture Bases* ; Denture Liners ; Dentures* ; Japan ; Methylene Chloride

BACKGROUND: Spinal nerve ligation injury causes a neuropathic pain syndrome that includes allodynia. Neuropathic pain is also induced by Freund's complete adjuvant (FCA)-induced inflammation. This study was designed to examine the development of mechanical and cold allodynia after FCA administration at the L4/L5 spinal nerves and to compare it with the effects of spinal nerve ligation at the same site. METHODS: Rats were randomly allocated into three groups: (i) treatment with tight ligation of the left L5/L6 spinal nerves, (ii) wrapping of the L5/L6 spinal nerves with Spongostan(R) soaked in FCA, or (iii) wrapping of the L5/L6 spinal nerves with Spongostan(R) soaked in saline. Mechanical and cold allodynia were measured by applying von Frey filaments or acetone in both hind paws. To examine the development of allodynia, the frequencies of hind paw withdrawal to each type of stimulus were measured. RESULTS: Both FCA administration and nerve ligation injury caused a marked mechanical and cold allodynia in the lesioned hind paw compared to saline treatment (P < 0.05). Furthermore, the frequencies of response of the lesioned hind paw to both types of stimulus were significantly greater than those on the contralateral side. CONCLUSIONS: These results suggest that administration of FCA to the spinal nerves can produce a mechanical and cold allodynia with a similar profile of pain facilitation as nerve ligation.
Acetone ; Animals ; Hyperalgesia* ; Inflammation ; Ligation ; Neuralgia ; Rats* ; Spinal Nerves*

OBJECTIVES: The purpose of this study was to examine the correlation between exposure to acetone and isopropyl alcohol (IPA) and the acquisition dyschromatopsia. METHODS: A study was performed on exposure group of 116 people exposed to and a group of 36 people not exposed to organic solvents were selected and examined. Their smoking and alcohol habits, symptoms, and exposure history were surveyed through questionnaires and interviews. Then dyschromatopsia was evaluated with the Lanthony D-15 d test in a room with standardized intensity of illumination. RESULTS: The statistical prevalence of dyschromatopsia was significantly higher in the exposed group (30.2%) compared to that found in the control group (19.4%). Out of the 116 subjects in the exposed group, 30 people had acquired dyschromatopsia (25.86%). The variables affecting the color confusion index, such as age, exposure, and the duration of exposure, were statistically significant variables. CONCLUSIONS: He prevalence of dyschromatopsia was found to be not significantly higher in the group with exposure to organic solvents compared to that found in the control group. In addition, a statistically significant correlation was found between exposure to organic solvents and the color confusion index.
2-Propanol ; Acetone ; Prevalence ; Questionnaires ; Smoke ; Smoking ; Solvents

This study was undertaken to investigate the optimal conditions for challenge testing with DNCB in 3 vehicles applied to guinea pigs in standardized amount/ area (pg/cm2) The results are sumrnarized as follows: 1) All test reactions were negative when tested in 10 unsensitized animals. 2) There were significant difference in positive rate between 0. 05%, DNCB in alcohol and 0.1% DNCB in alcohol, but there were no significant difference between 0. l%, DNCB in alcohol and 0, 2% DNCB in alcohol. Same results were obtaincd when DNCR was dissolved in acetone. 3) Acetone gives the significantly higher degree of positive reactions, indicating that alcohol may be the safer vehicle in eliciting a response than acetone. 4) With DNCB in olive oil, relatively few animals reacted compared to the results obtained with alcohol and acetone. Furthermore, olive oil is slippery and difficult to utilize when attempting to delineate surface area. 5) With alcohol, we obtained a good correlation between the amount applied and the resulting response, showing that this vehicle might be a superior vehicle in eliciting contact allergy.
Acetone ; Animals ; Dinitrochlorobenzene* ; Guinea Pigs* ; Guinea* ; Hypersensitivity* ; Olea ; Olive Oil

STATEMENT OF PROBLEM: Ti-6Al-7Nb alloy is used instead of Ti-6Al-4V alloy that was known to have toxicity. PURPOSE: This study was performed to investigate the effect of electrolyte concentration on the surface characteristics of anodized and hydrothermally-treated Ti-6Al-7Nb alloy. MATERIALS AND METHODS: Discs of Ti-6Al-7Nb alloy of 20 mm in diameter and 2 mm in thickness were polished sequentially from 300 to 1,000 SiC paper, ultrasonically washed with acetone and distilled water for 5 min, and dried in an oven at 50 degrees C for 24 hours. Anodizing was performed at current density 30 mA/cm2 up to 300 V in electrolyte solutions containing beta-glycerophosphate disodium salt hydrate (beta-GP) and calcium acetate (CA). Hydrothermal treatment was conducted by high pressure steam at 300 degrees C for 2 hours using a autoclave. All samples were soaked in the Hanks' solution with pH 7.4 at 36.5 degrees C for 30 days. RESULTS AND CONCLUSION: The results obtained were summarized as follows; 1. After hydrothermal treatment, the precipitated HA crystals showed the dense fine needle shape. However, with increasing the concentration of electrolyte they showed the shape of thick and short rod. 2. When the dense fine needle shape crystals was appeared after hydrothermal treatment, the precipitation of HA crystals in Hanks' solution was highly accelerated. 3. The crystal structures of TiO2 in anodic oxide film were composed of strong anatase peak and weak rutile peak as analyzed with thin-film X-ray diffractometery. 4. The Ca/P ratio of the precipitated HA layer was equivalent to that of HA crystal in Hanks' solution.
Acetone ; Alloys* ; Calcium ; Hydrogen-Ion Concentration ; Needles ; Steam ; Water