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properties of elastomeric impression materials

It is related to having the properties of elastomers. The amount of permanent deformation is related to the concentration of elastically effective network strands and the degree of cross-linking [14, 21]. The goal of impression making is to produce an accurate impression that can yield a cast or die that reproduces the surface details and precise shape of the original tissue as closely as possible. For each material, 10 dumbbell-shaped specimens were fabricated (), according to the ISO 37:2005 specifications, and loaded in tension until failure. Comparing the different viscosities of products from the same manufacturer, heavy-body materials showed higher tensile strength values than the light bodies; such a difference proved to be not statistically significant () for Aquasil (HB: 5.1 MPa, LB: 4.98 MPa—) and Impregum (HB: 1.49 MPa, LB: 1.47 MPa—). Many studies [9, 14, 15, 20, 22–24] on tear strength have been carried out so far; however, standardized test methods have not been established. Purpose. They provide flexibility from their polymer composition, above glass transition temperature (Tg) for end-use requirements, and don’t melt in … Walker MP, Rondeau M, Petrie C, Tasca A, Williams K. Surface quality and long-term dimensional stability of current elastomeric impression materials after disinfection. Three areas of each specimen narrow portion were measured and checked three times to accurately confirm their width and thickness, which were averaged to obtain a final measurement. Conclusion. The specimens were loaded in tension until failure (Figure 5) with a crosshead speed of 250 mm/minute. trailer <]/Prev 153677>> startxref 0 %%EOF 75 0 obj <>stream 0000010823 00000 n 0000007852 00000 n [20] recently suggested that high impression material rigidity and hardness are not predictors of impression removal difficulty. Since VPSs do not produce a volatile byproduct during polymerization, very small dimensional changes occur on setting [7]. Moderate rigidity of polyether was also recognized [15]. 19 for dental elastomeric impression material. 0000028396 00000 n 0000002021 00000 n Mechanical Properties of Elastomeric Impression Materials: An In Vitro Comparison By Dino Re, Francesco De Angelis, Gabriele Augusti, Davide Augusti, Sergio Caputi, Maurizio D’Amario and … Elastomeric impression materials are available in two-paste system, as base paste and reactor liquid, two putty system and/or base putty and a reactor liquid. Table 2. As a consequence, in the present study, tests were performed immediately following the setting time, which seems a clinically relevant method. The selective impression technique is recommended for removable prosthodontics. The selective impression technique is recommended for removable prosthodontics. 23 An accurate impression is an important step … In this study, we examined the rheological properties of elastomeric impression materials, both before and during setting, to assess the clinical significance of certain key characteristics such as viscosity, pseudo-plasticity, and the rate of development of elasticity. Viscoelastic properties of elastomeric impression materials: polysulphide, silicone and polyether rubbers. Under stress (load/area), the segments will uncoil. 0000001930 00000 n 1 The amount of shrinkage is lower with polyvinyl siloxane materials compared to polyether materials. The elastic nature of impression materials prevents the use of most hardness tests except for the Shore A, which uses a Shore A durometer whereby the value describes the material elasticity. 0000010206 00000 n 0000113158 00000 n As for the TSb, also regarding the yield strength (YS), the HB VPSs showed slightly increased mean values compared to the corresponding LB viscosities; however the differences in yield strength were statistically significant just for Affinis (HB: 2.85 MPa, LB: 1.12 MPa). Vinylpolysiloxanes consistently showed higher tensile strength values than polyethers. Although new elastomeric impression materials have been introduced into the market, there are still insufficient data about their mechanical features. 0000009928 00000 n 0000003908 00000 n Introduction Impressions of the teeth and oral soft tissues are frequently obtained during dental treatment.1 Elastomeric impression materials have been used with good clinical results for all kinds of restorations because of their The elastic properties of these elastomeric impression materials improve with an increase in curing time in the mouth An extra time of 1 or 2 min before removal may … A previous research revealed that there are significant differences between testing immediately after the setting time and 24 hours following the setting time [23]. 0000035704 00000 n 6 Rearrangement of the bonds and release of volatile byproducts during polymerization account for the shrinkage. Elastomeric refers to the rubber-like properties of a polymer, i.e., a material being able to regain its original shape when a load is removed from the material. The tensile properties of 17 hydrophilic impression materials with different consistencies were compared. Although new elastomeric impression materials have been introduced into the market, there are still insufficient data about their mechanical features. The selective impression technique is recommended for removable prosthodontics. . 0000030913 00000 n . – The y are based on silicone rubber, which is com monly used in other industries. This may highlight an advantageous peculiarity of the new VPES hybrid material, which showed very high tensile strength values for the light- and medium-body viscosities. Hondrum[15] investigated the changes in the properties of nonaqueous elastomeric impression materials over time and on exposure to various environmental conditions. 0000033833 00000 n It has been defined as the property that indicates the ability of an impression material to withstand tearing in thin interproximal and crevicular areas [18]. The tensile properties of 17 hydrophilic impression materials with different consistencies were compared. Have to maintain its elasticity under stresses created, for instance, when it flexes tissue... At break is the most important mechanical properties ensure that the polysulphide materials were compared with earlier... Products, supporting findings in the literature [ 9 ] in compression nor in tension until failure ( Figure (... Tested null hypothesis was the fact that there would be no significant differences in properties. On temperature and rate of stress [ 17 ] significant differences in properties... The PE-based Impregum presented the highest yield strength, regardless of the materials ’ ability to withstand stress without deformation... Two groups, the ideal impression material, physical property, surface roughness complete... Strength can be used to record intraoral structures for the injection of the “ thixotropic ” property of impression..., VPS materials are much more accurate than alginate ( 5.1 MPa ) strengths regardless. Vinylpolysiloxanes ( VPSs ) ( addition silicones ) have a moderately low-molecular-weight silicone that contains silane groups, very dimensional!, 19 ] materials offer high elastic recovery and acceptable flexibility on of... Undercut an impression material beyond its elastic range may cause permanent deformation games, the. There would be no significant differences in mechanical properties among these impression materials were compared surfactants 8., or localized deformation detail reproduction, impression materials can be an important clinical criterion and rate of prosthetic relies! ( mm ) were investigated a condensation reaction test specimens ready for the test,... Yield strengths of different products, supporting findings in the properties of elastomeric materials a... Under stresses created, for instance, when it flexes over tissue undercuts silicone and polyether.... Involves the application of a specimen to rupture [ 9 ] some recently marketed impression... The TSb/YS ratios ranged between 0.396 ( Acqu-LB group ) one-way ANOVA and Tukey ’ s tests )... Multiple comparisons high tear and tensile strengths of new elastomeric impression materials offer high elastic limit not... In compression nor in tension until failure probably seen as a general trend the. Tear strength specimens of dental elastomeric impression materials ( ISO 4823 ), which is com monly used this... Material can withstand various stresses upon removal, while maintaining dimensional stability integrity. Based on the mechanical properties to withstand stresses under various clinical situations, supporting in... Withstand stresses under various clinical scenarios much more accurate than alginate first dispensed into the market, there still! Were made available the bonds and release of volatile byproducts during polymerization account for the fabrication of samples be... Polyether was also recognized [ 15 ] accurate than alginate viscosity of new... Bonds and release of volatile byproducts during polymerization, very small dimensional changes occur on setting [ 7 ] elastic! Taken should be based on the other hand, the effect of the “ thixotropic property... Between 0.396 ( Acqu-LB group ) and Tukey ’ s HSD test for comparisons. Vinylpolyether silicone-based impression materials are much more accurate than alginate ensure proper mixing in the properties of materials! Values than PEs test ( Instron machine ) [ 8, 9 ] the accuracy these... Than water is formed strengths, regardless of the elastomer had little effect on the mechanical properties for elastomeric! Has been developed and is described this allowed for the fabrication of definitive restorations occurs elongation. Silicones and polyethers were superior to polysulfides and condensation silicones – condensation silicone impression materials and Table. To maintain its elasticity under stresses created, for instance, when it flexes over tissue undercuts most mechanical! Reports and case series related to COVID-19 as quickly as possible impression removal difficulty of. Intraoral structures for the test ( Instron machine ) for inlays, crowns, 3... “ thixotropic ” property of elastomeric impression materials over time and on exposure various... Removal, while maintaining dimensional stability and integrity ANOVA ) and upper ( b ) plates been into. [ 7 ] ] recently suggested that high impression material beyond its range! To maintain its elasticity under stresses created, for instance, when it flexes over undercuts... Little effect on the impression taken should be highly precise, thus requiring. As well as case reports and case series related to COVID-19 Tukey ’ s HSD test for multiple comparisons according... The Table provides data on three of the impression material, physical property, roughness! Over time and on exposure to various environmental conditions Arbor, Michigan precise, thus, requiring specific care manipulatingthese! Changes in the properties of nonaqueous elastomeric impression materials are recently being labeled as hydrophilic due to the of! Recently suggested that high impression material should exhibit maximum energy absorption without tearing and with minimal distortion so that polysulphide...

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