Home About us Contact
|
Home About us Contact | ||
|
|
||
Lining Material (lining + material)
Selected AbstractsThe effect of thermocycling on peel strength of six soft lining materialsJOURNAL OF ORAL REHABILITATION, Issue 6 2002A. Sertgöz The bond strength of two heat-cured and four cold-cured soft lining materials was compared using a peeling test method before and after thermocycling. Tested soft lining materials were Molloplast B, Mollosil, Ufigel P, Ufigel C, Permaquick and Permaflex. Six specimens, 6·5 × 2 × 0·3 cm, for each group were prepared according to the manufacturers' instructions. Control groups were stored in a humidor for 24 h, whereas the others were thermocycled in a water bath between the 5 and 55 °C for 5000 cycles. Peel strength of samples were measured using an Instron Universal testing machine at a cross-head speed of 5 mm min,1. The types of failure were observed using an electron microscope. The highest peel bond strength values were calculated for Permaflex and Permaquick before and after thermocycling, respectively. Molloplast B, Mollosil, Ufigel P and Permaquick demonstrated an increase in peel strength after thermocycling, with Permaquick lining material having statistically significant increase. However, decrease in peel strength was observed for Ufigel C and Permaflex after thermocycling. Failure mode within the control groups was cohesive for Molloplast B, Permaquick and Permaflex, whereas adhesive for Ufigel P and Ufigel C. Mollosil demonstrated a mixed mode of failure for both thermocycled and control groups. [source] Effect of cavity varnish, amalgam liner or dentin bonding agents on the marginal leakage of amalgam restorationsJOURNAL OF ORAL REHABILITATION, Issue 5 2001S. Belli The purpose of this in vitro study was to compare marginal leakage of Class II amalgam restorations lined with different agents (two new generation dentin bonding systems, a cavity varnish and an amalgam liner). Forty freshly extracted human molar teeth were divided into five groups. Class II preparations were prepared in the mesial and distal surfaces of each molar. While the cavities in two groups were lined with two new generation bonding systems, the other two groups were treated with an amalgam lining material and a cavity varnish. Fifth group was used as control, without any lining. Amalgam* was hand-condensed into each preparation. Specimens were thermocycled, stained and sectioned. Microleakage was graded using a stereomicroscope. Mean microleakage scores for occlusal and cervical margins were calculated and analised. For the leakage values on occlusal margins, Kruskal,Wallis test indicated no significant difference in all groups. For the leakage values on cervical margins, Kruskal,Wallis test indicated significant difference in four groups when compared with controls (P < 0·001). On the other hand, there was no significant difference between the occlusal and cervical leakage values in each group. [source] Experimental model for creep groan analysisLUBRICATION SCIENCE, Issue 1 2009Z. Fuadi Abstract A simple experimental model for a fundamental investigation of creep groan generating mechanism is introduced. It is a calliper slider model that is developed based on the operating principle of a real brake system and has the ability to generate creep groan quantitatively comparable to those recorded on the real brake system. The advantage of the model is that it is possible to take into account many parameters, such as surface roughness of mating materials, properties of mating materials and structure's stiffness, so that their effects for creep groan phenomenon can be analysed. The usefulness and potential of the model are demonstrated by its ability to generate creep groan using a real brake lining material that is well known to the brake industry as a material that easily produces creep groan in real applications. Parametric analysis is conducted, and the effects of several sensitive parameters to stick-slip frequency characteristic of creep groan are highlighted. Copyright © 2008 John Wiley & Sons, Ltd. [source] Pleural plaques in dentists from occupational asbestos exposure: A report of three casesAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 12 2009FCCP, L. Sichletidis MD Abstract Background White asbestos (chrysotile) has been used in dentistry since 1930 when it was introduced as a lining material for casting rings. Methods All three patients presented with pleural plaques on chest X-rays as well as on CT-scans. They were working as dentists for 35,45 years. Under the instructions of the first dentist we represented precisely the whole process of manipulating a kind of paper that contained asbestos. In order to measure asbestos fibers concentration we used the membrane filter method and phase contrast optical microscopy. Dry asbestos sheets were scanned with x-ray diffraction and electron microscope. Results Analysis of the filter demonstrated 0.008 fibers/cm3 during the sampling period. X-ray diffraction analysis revealed that the material consisted of chrysotile exclusively. Electron microscope pictures confirmed the presence of chrysotile. Conclusion Everyday occupational exposure for many years even to low asbestos levels, under poor ventilation conditions in a closed space, could cause pleural lesions. Am. J. Ind. Med. 52:926,930, 2009. © 2009 Wiley-Liss, Inc. [source] Proliferative activity of cells from remaining dental pulp in response to treatment with dental materialsAUSTRALIAN DENTAL JOURNAL, Issue 1 2010AN Lutfi Abstract Background:, The biological examination of pulp injury, repair events and response of dental pulp stem cells to dental restorative materials is important to accomplish restorative treatment, especially to commonly used dental materials in paediatric dentistry, such as glass ionomer cement (GIC) and calcium hydroxide (Ca(OH)2) lining cement. Methods:, Healthy patients aged between 9 to 11 years with carious primary molars without pulp exposure were selected and divided into two groups: Group 1 (teeth restored with GIC) and Group 2 (teeth lined using Ca(OH)2 and restored with GIC). The proliferative activity of stem cells of teeth between these two groups was compared using colourimetric cell proliferation reagent, alamarBlue. Immunocytochemistry and flow cytometry confirmation were performed using mesenchymal stem cell markers, CD105 and CD166. Results:, The proliferative activity using alamarBlueÔ assay showed that cells derived from the remaining dental pulp of exfoliated deciduous teeth were positive for CD105 and CD166 and exhibited no difference between the two groups. Conclusions:, It can be concluded that the use of Ca(OH)2 or GIC as a lining material in indirect pulp capping procedures has the same effect on cells derived from the remaining dental pulp of exfoliated deciduous teeth which have responded favourably to the restorative treatments. [source] Descriptions and biological notes of Ctenoplectra bees from Southeast Asia and Taiwan (Hymenoptera: Apidae: Ctenoplectrini) with a new species from North BorneoENTOMOLOGICAL SCIENCE, Issue 3 2009I-Hsin SUNG Abstract Six Ctenoplectra species are recorded from Southeast Asia and Taiwan. They are C. chalybea Smith, C. cornuta Gribodo, C. davidi Vachal, C. elsei Engel, C. sandakana sp. nov. and C. vagans Cockerell. Females of C. sandakana sp. nov. from North Borneo are similar to the mainland species C. chalybea, but differ mainly in the clypeal keel and the length of the antennal segments. The small blackish species, C. cornuta, is distributed in Myanmar, China and Taiwan and C. davidi is distributed in China, Russia and Taiwan; both species are seen at the flowers of Thladiantha. Ctenoplectra chalybea was collected from the Malay Peninsula, Myanmar, Taiwan and Vietnam. Ctenoplectra apicalis Smith and C. kelloggi Cockerell are allied to C. chalybea; however, C. kelloggi is excluded from this study due to insufficient material. A key to the six known Ctenoplectra species is given. The large metallic species, C. chalybea and C. elsei, visit flowers of Momordica cochinchinensis (Lour.) Spreng. For the first time observations on the nest structures of C. chalybea and C. cornuta are presented. They choose remarkable places, such as artificial structures and buildings, for nest sites. The nest architecture prevents rain and direct sunlight from entering the nest. Bees used pre-existing holes or crevices in wood for nesting shelters and collected soil and appeared to mix it with some other substance to build nests. The cell lining materials and rubbing behaviors against the cell wall suggest that Ctenoplectra bees use floral oil mainly for cell lining materials. [source] Changes in surface roughness and colour stability of soft denture lining materials caused by denture cleansersJOURNAL OF ORAL REHABILITATION, Issue 2 2003C. Jin summary, Soft denture lining materials were immersed into solutions of denture cleansers for 8 h at room temperature, and immersed into distilled water for the remainder of the 24-h period at 37 °C. Surface roughness of the soft denture lining materials was measured by contact type surface roughness instrument. For the colour stability test, soft denture lining materials were immersed in the denture cleansers as described above for 180 days. Finally, the colour changes of each material were quantitatively measured by a photometrical instrument to obtain the colour differences between newly processed specimen and immersed specimens (P < 0·01). An autopolymerizing silicone material, Evatouch, exhibited severe changes in surface roughness by all denture cleanser, and the generic material GC Denture Relining showed the minimal changes. Severe colour changes were also observed with some liner and cleanser combinations (P < 0·01). Except for Evatouth, the four silicone soft liners were more stable in surface roughness and in colour change than the two acrylic soft liners. One autopolymerizing silicone (GC denture relining) and one heat curing silicone (Molloplast B) demonstrated the best stability. [source] The effect of thermocycling on peel strength of six soft lining materialsJOURNAL OF ORAL REHABILITATION, Issue 6 2002A. Sertgöz The bond strength of two heat-cured and four cold-cured soft lining materials was compared using a peeling test method before and after thermocycling. Tested soft lining materials were Molloplast B, Mollosil, Ufigel P, Ufigel C, Permaquick and Permaflex. Six specimens, 6·5 × 2 × 0·3 cm, for each group were prepared according to the manufacturers' instructions. Control groups were stored in a humidor for 24 h, whereas the others were thermocycled in a water bath between the 5 and 55 °C for 5000 cycles. Peel strength of samples were measured using an Instron Universal testing machine at a cross-head speed of 5 mm min,1. The types of failure were observed using an electron microscope. The highest peel bond strength values were calculated for Permaflex and Permaquick before and after thermocycling, respectively. Molloplast B, Mollosil, Ufigel P and Permaquick demonstrated an increase in peel strength after thermocycling, with Permaquick lining material having statistically significant increase. However, decrease in peel strength was observed for Ufigel C and Permaflex after thermocycling. Failure mode within the control groups was cohesive for Molloplast B, Permaquick and Permaflex, whereas adhesive for Ufigel P and Ufigel C. Mollosil demonstrated a mixed mode of failure for both thermocycled and control groups. [source] | ||||||||||