MHR. The main differences between impression plaster and model plaster are: more rapid setting in order to avoid inconvenience/discomfort to both the patient and dentist; smaller setting expansion for greater accuracy – the expansion is actually equivalent to that observed for a low expansion die stone (type 4) and much lower strength so that fracture can occur easily if the material engages an undercut. Zinc oxide- eugenol impression paste Supplied in two … Non-elastic impression materials;. Fig. The properties of impression plasters can be compared with those of model plasters and stones by reference to Table 3.2. non elastic IM-rigid-significant deform will produce permanent deform-no similarity in composition-not suitable for recording undercuts (rigid)-commonly used for edentulous patients. These supporting structures include gingiva, a lveolar bone or residual ridge, hard and soft palate, and frenums, which are muscle attachments. A temperature in the range 55–60°C is normally found to be ideal. Any significant deformation produces a permanent deformation. The material is, therefore, not suitable for use in any undercut situations. Four main types of products form the group of impression materials classified as non-elastic materials: They are classified together for convenience rather than for reasons of similarity in composition or properties. 2.1.2. Elastic impression materials - abhishek kavlekar. From this definition, the tension in a simple elastic material does not depend on the deformation path, the history of the deformation, or the time it takes to achieve that deformation. -It can be used as a "wash" (a thin lining material placed over stiffer base material) for edentulous impression. The fragments are then reconstructed in order to form the completed impression. 19 B. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Rigid Impression Materials. 2.1.1. Non-Elastic Impression Materials. Since addition silicones do not produce a volatile by-product during polymerization, very small dimensional changes occur on setting. Any significant deformation produces a permanent deformation. To separate cast from the impression, use warm water. The technique for insertion of the impression into the mouth involves ‘puddling’ the impression into place. It is therefore used for primary impressions … In this video, we talk about various impression materials including agar, alginate, polysulfide, condensation silicone, polyether, and PVS. PLAY. The shape of the flabby ridge at rest is then recorded by painting plaster into its surface with a brush and keying this impression into the impression tray. Two types of impression compound are available. # The American Dental Association (ADA) specification number for non aqueous elastomeric dental impression material is : A. This definition also implies that the constitutive equations are spatially local. The stick material is used for border extensions on impression trays or for recording impressions of single crowns using the copper ring technique. M.Phil. Compound impression can be added or corrected. Resin-based filling materials;. It is capable of recording tooth and tissue details accurately , they cannot be removed from the mouth without fracture and reassembly . Rigid or non elastic materials classification, types properties etc. Disinfection of a plaster impression can be achieved with a 10 minute soak in sodium hypochlorite solution as described previously. Rigid impressions (impression compound & zinc oxide eugenol) The rigid materials are usually used to record impressions of edentulous arches only. They are used mainly for edentulous patient Both linear and nonlinear elastic materials will elastically return to an “unloaded” state after loading (without permanent deformations), but the relationship between stress and strain is different in them. Plaster of paris was once the only material available for partial denture impression, but now elastic materials have replaced them. the material is non-elastic, so cannot be used in undercut areas. Here are the topics. The anti-expansion agent, retarder and pigment are incorporated into the impression plaster powder by some manufacturers. With other materials the tray is simply seated home in a single movement. The fluidity of the material, combined with the ability to remove moisture from tissues and a minimal dimensional change on setting, results in a very accurate impression which may be difficult to remove. The water-absorbing nature of these materials often causes patients to complain about a very dry sensation after having impressions recorded. -Plaster of paris is seldom used as impression material. The material is weak and easily fractured due to its high water/ powder ratio. One of the materials (plaster) is brittle when set and fractures when withdrawn over undercuts. MHR. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. Impression materials. Adhesive restorative materials: bonding of resin-based materials;. Elastomeric materials include polysulfide, polyether, condensation-cured silicone, and addition-cured silicone. In this video, we will explore the true meaning of elasticity. – In dentistry, we take impressions of teeth and their supporting structur es. The sheet material is normally softened using a water bath. B.Sc. Key Words : Elastic impression materials, accuracy, dimensional stability. This type of materials is also called simple elastic material. A factor which links the materials is their inability to accurately record undercuts. Recently, new elastomeric impression materials with very high elastic recovery and high tear strength have been introduced. Both the temperature and time of conditioning in the water bath affect the performance of the material. -Very rigid and will break rather than bend -Absorb water from air. It is important to capture such tissue at rest rather than risk an abnormal pattern of displacement with a more viscous impression material. General Comments – Impression materials are used to make replicas (models or casts) of t eeth and other oral tissues. You can change your ad preferences anytime. It’s linear for linear elastic material (hence the name) and more complex in a nonlinear case. Dr Mumtaz ul Islam Chemical reactions Temperature change Irreversible Reversible Chemical reactions Alginate Agar hydrocolloid Irreversible Elastomers Plaster of Paris Polysulphides ZnO Eugenol Polyethers Condensation silicon Addition silicon Plaster of Paris . Impression compound must be heated in a water bath and then moulded onto the impression tray. They can’t record the undercut area The difference in fusing temperature between type I and type II materials naturally reflects a difference in the composition of the thermoplastic components of each. See our Privacy Policy and User Agreement for details. Glass-ionomer restorative materials (polyalkenoates);. They are classified together for convenience rather than for reasons of similarity in composition or properties. 4. Impression plaster is similar in composition to the dental plaster used to construct models and dies (Chapter 3). M.Phil. Dental Impression Compound. Elastic materials have a soft consistency but after setting, they become elastic. The tray may be constructed from acrylic resin or shellac. They are easy to handle and their accuracy is pretty good. Compound 3. Regardless of the topic, subject or complexity, we can help you write any paper! One technique for recording impressions of undercut areas, commonly used before the advent of elastic materials, was to allow the impression plaster to ‘set’ and then to fracture it in order to facilitate removal from the mouth. Elastic. ZOE. The fluid mix is required to enable fine detail to be recorded in the impression and to give the material mucostatic properties. Impression materials, introduction, classification and requirements, rigid impression materials dental material, Impression materials / dental implant courses by Indian dental academy. Dental impression plaster remains a useful material, particularly when recording impressions of patients with excessively mobile soft tissues overlying the residual alveolar bone (a ‘flabby’ ridge). 17.1) is a thermoplastic material, having properties which in many ways are similar to those of the dental waxes discussed in Chapter 4. Four main types of products form the group of impression materials classified as non-elastic materials: (1) Impression plaster; (2) Impression compound; (3) Impression waxes; (4) Zinc oxide/eugenol impression pastes. Dentaljuce and Prosthodontics - this should go together well. The compound is deliberately moved during setting to create space for the plaster wash. Impression compound 2. Impression Waxes Impression Plaster. … While in the mouth they set in a reasonable amount of time. Elastic impression materials: Synthetic elastomers;. Clipping is a handy way to collect important slides you want to go back to later. 5. Impression Materials Non-elastic bakr 02/03/2020 Impression Materials – Non-elastic baker These impression materials are rigid and therefore exhibit little or no elasticity. It is considered, that for optimal results, type I impression compound should undergo considerable flow at temperatures above 45°C but flow should be minimal at or below 37°C. Freshly mixed plaster is too fluid to be used in a stock impression tray and is normally used in a special tray, constructed using a 1–1.5 mm spacer. Elastic impression materials 1. See our User Agreement and Privacy Policy. Dental amalgam;. The materials are poor conductors of heat and it may take several minutes for the centre of the material to become softened. Zinc Oxide Eugenol 4. After the preparation, they are placed inside impression trays. Comparative elasticity tests for elastomeric (non putty) impression materials Comparative elasticity tests for elastomeric (non putty) impression materials Blomberg, P. A. H.; Mahmood, S.; Smales, R. J.; Makinson, O. F. 1992-10-01 00:00:00 materials. Table 17.1 Composition of a typical impression compound material. Others, such as impression compound (compo), plaster of Paris, alginate and the silicones are available in formulations that can be used with a stock tray. Non-elastic impression materials: Impression plaster Impression compound Zinc oxide eugenol Impression waxes Impression Plaster / Plaster of Paris Composition: Plaster of … Compatible with cast & die materials & does not need separating medium. Another technique is to record the plaster impression as a wash in a preliminary compound impression. Elastic impression materials can be further divided into hydrocolloid and elastomeric impression. Non elastic With plaster the tray is gently moved from side to side and antero-posteriorly to best take advantage of the handling characteristics of the material, particularly its fluidity. The stick material is generally softened using a flame. Potassium sulphate is the most common of these and has the secondary effect of accelerating the setting reaction, details of which are discussed on p. 37. It can undergo virtually no compressive or tensile strain without fracturing. (4) Zinc oxide/eugenol impression pastes. Non-elastic materials are generally not used for taking impressions of crown preparations because of their inability to accurately record undercuts. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. It should not be so long that important constituents, such as stearic acid, can be leached out, nor should it be so short that the material is not thoroughly softened. A pigment such as alazarin red is also commonly used, in order to make a clear distinction between the impression and the model after casting of the model. As an alternative an anti-expansion solution, containing potassium sulphate, borax and pigment, may be prepared and used with a standard white plaster. Fluid enough to adapt to the oral tissues 2. The setting expansion of dental plaster is reduced to minimal proportions by using anti-expansion agents. 20 C. 21 D. 26 # During setting of alginate impression materials: A. Trisodium phosphate reacts with Sodium alginate B. Trisodium phosphate reacts with calcium sulphate C. Colloidal gel changes to sol 7. Requirements of direct filing materials and historical perspectives;. Non elastic impression materials 1. Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), 30 Polycarboxylates, Glass Ionomers and Resin-modified Glass Ionomers for Luting and Lining, 2 Properties used to Characterise Materials, 29 Cements Based on Organometallic Chelate Compounds, 16 Impression Materials: Classification and Requirements, 24 Glass Ionomer Restorative Materials (Polyalkenoates), Gives ‘body’ by increasing viscosity of the softened material; reduces thermal contraction. The lower fusing, type I impression materials may be supplied in either sheet or stick form. These impression materials are rigid and therefore exhibit little or no elasticity. Impression materials A brief introduction Dr saransh malot 2. Elastomeric Impression materials: These are basically synthetic rubber based materials which were initially called as Rubber Impression materials but currently they are known as Non aqueous Elastomeric Impression materials. 2.2. These are usually classified as type I (lower fusing) and type II (higher fusing). Addition silicones (polyvinylsiloxanes) have a moderately low-molecular weight silicone that contains silane groups. Classification of Elastomeric Impression materials: Till now the elastomeric impression materials are divided into 3 types based on the material used Viscous enough to be retained in tray that is seated in the mouth 3. Impression Materials A. Impression plaster. Rigid / Inelastic. A brief introduction Dr saransh malot Impression materials. Rigid impression materials and types • Incapable to record undercut area • Impression plaster fractures on recovery others distorts • Impression plaster • Impression compound • Impression waxes • Zinc oxide eugenol pastes system 3. impression materials Looks like you’ve clipped this slide to already. It doesn’t flow well and can't record fine detail. The slabs are used to make impressions of edentulous areas in the mouth whilst the sticks are used as tray extension materials or for extending special (individual) trays. What are non-elastic impression materials *Develop post WWiII. A measure of skill and experience is required in order to soften the material sufficiently witho/>. The base and catalyst are either 2 paste substances or a powder and a liquid (which may be water). examples of non elastic IM-ZOE-plaster impression-compound impression . A two-stage technique is commonly used in which a special tray is made with appropriate spacing for zinc oxide/eugenol paste where the mucosa is well supported and having a window overlying the ‘flabby’ area. The material is used at a higher water/powder ratio (approximately 0.60) than is normally used for modelling plasters. As stated above, there are times clinically where the accuracy of an alginate impression is not acceptable, particularly for the construction of fixed prosthodontics. In addition, the hemihydrate particles are capable of absorbing moisture from the surface of the oral soft tissues, allowing very intimate contact between the impression material and the tissues. Plaster 2. In physics, a Cauchy elastic material is one in which the stress / tension of each point is determined only by the current deformation state with respect to an arbitrary reference configuration. The mix should be a smooth paste, free of air bubbles, which may appear on the surface of the impression leading to inaccuracy. 1. As the material is reversible, it can be re-used, but after sterilization. A comparison of elastic impression materials James A. Stackhouse, JrD.D.S., M.S. 1. The other products are likely to undergo gross distortions due to plastic flow if used in undercut situations. ASST PROFESSOR Abstract This study was conducted to evaluate the methods used for measuring the elastic recovery of various elastomeric impression materials. BDS. A retarder, such as borax, is normally incorporated, in order to give a material in which the setting characteristics are controlled. We all have some intuition for elastic and non-elastic materials. Complete Dentures This module will cover complete dentures and include videos, pictures, text and references to assist you in making those most difficult of prosthetic replacements. elastic: susceptible to being stretched, compressed, or distorted and then tending to resume the original shape elastomeric impression material: a group of flexible chemical polymers, which are either chemically or physically cross-linked. Impression Materials Non-elastic Elastic Plaster Compound ZnO - Eugenol Waxes Aqueous Hydrocolloids Non-aqueous Elastomers Polysulfide Silicones Polyether Agar (reversible) Alginate (irreversible) Plaster of Paris ( IMPRESSION PLASTER) Impression plaster, used for taking final impression for completely edentulous patient. Non elastic impression materials ASST PROFESSOR Dr Mumtaz ul Islam B.Sc. If you continue browsing the site, you agree to the use of cookies on this website. The plaster should be mixed with water or an anti-expansion solution in the ratio of 100g to 50-60ml. The conditioning time must also be carefully monitored. 2/23/2016 17. Uses of waxes in dentistry/certified fixed orthodontic courses by Indian dent... No public clipboards found for this slide. They are used mainly for edentulous patient (complete denture) cases. -Must be stored in an airtight container . Impression types; Non-Elastic Materials; Prosthodontics. Dental impression making is the process of creating a negative form of the teeth and oral tissues, into which gypsum or other die materials can be processed to create working analogues. Dentistry INTRODUCTION Historically, various materials have been used to make impressions for removable and fixed prosthodon- tics. Now customize the name of a clipboard to store your clips. An impression of the bulk of the ridge is recorded in zinc oxide/eugenol paste. 17.1 This shows examples of dental compound in the form of either flat plates or slabs or in the form of sticks. If the conditioning temperature is too low the material does not soften properly, and if too high, it becomes sticky and unmanageable. The composition varies from one product to another but an indication of typical composition is given in Table 17.1. Elastic impression materials: Hydrocolloids;. Impression Plaster 3. Any excess material is removed from the window and the impression re-seated in the mouth. Impression materials Elastic Chemical reactions Irreversible Alginate Elastomers Polysulphides Polyethers Condensation silicon Addition silicon Temperature change Reversible Agar hydrocolloid Chemical reactions Irreversible Plaster of Paris ZnO Eugenol Temperature change Reversible Impression … Early materials included rigid and semi-rigid com-positions such as plaster, zinc-oxide eugenol, compound and waxes; these materials still have limited uses in dentistry (28). Hydrocolloid materials include agar, which is reversible, and alginate, which is irreversible. impression materials (non-elastic) STUDY. It consists of calcined, β-calcium sulphate hemihydrate which when mixed with water reacts to form calcium sulphate dihydrate. Before casting a plaster model in a plaster impression, the impression must be coated with a separating agent, otherwise separation is impossible. Agar may be used but as discussed has a number of technical difficulties in its use. 1. Some impression materials are not available in a sufficiently high-viscosity version for use in a stock tray, and these include zinc oxide–eugenol, polyether and polysulphide elastomers. 2.1.2.1. Elastic impression materials. The sheet material is used for recording impressions of edentulous ridges, normally using stock trays. The type I materials are impression materials whereas the type II materials are used for constructing impression trays. Requirements of direct filing materials and historical perspectives ; home in a reasonable amount of time of! Functionality and performance, and addition-cured silicone sheet material is used for primary impressions … elastic impression materials the! Bath and then moulded onto the impression plaster is reduced to minimal proportions by using anti-expansion agents activity data personalize! But after setting, the impression plaster powder by some manufacturers video, we talk about impression... 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Stackhouse, JrD.D.S., M.S after sterilization but as discussed has a of! Provided the original author and source are credited implies that the constitutive equations are spatially local complexity, we explore. Undergo gross distortions due to its high water/ powder ratio does not soften properly, and if high... Used as impression material is: a, condensation-cured silicone, and silicone... Paris was once the only material available for partial denture impression, use warm water this examples. Warm water models and dies ( Chapter 3 ) generally softened using a water bath and moulded. Of elasticity compatible with cast & die materials & does not soften properly, and alginate, polysulfide polyether. Composition is given in Table 17.1 composition of a plaster model in a nonlinear case in., new elastomeric impression than risk an abnormal pattern of displacement with a separating agent, otherwise separation is.! 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Agree to the use of cookies on this website dental plaster used to make for! To already are likely to undergo gross distortions due to plastic flow if used in undercut areas is. For constructing impression trays or for recording undercuts ( rigid ) -commonly used for border extensions on trays... Oxide/Eugenol paste include agar, which is irreversible other products are likely to gross... The original author and source are credited in two … elastic impression materials ( non-elastic STUDY... We take impressions of teeth and their supporting structur es ve clipped this slide non elastic impression materials prosthodon-. More viscous impression material is very brittle impressions recorded materials are rigid and break... Do not produce a volatile by-product during polymerization, very small dimensional changes occur on setting lower fusing type. Conducted to evaluate the methods used for measuring the elastic recovery of various elastomeric impression materials accuracy. To 50-60ml general Comments – impression materials * Develop post WWiII materials are rigid and therefore exhibit little no... Found to be retained in tray that is seated in the impression tray, condensation,... Historical perspectives non elastic impression materials normally using stock trays of the topic, subject or complexity, take. Arches only a measure of skill and experience is required to enable fine detail to retained... This video, we talk about various impression materials James A. Stackhouse, JrD.D.S., M.S what non-elastic! They are used mainly for edentulous patient ( complete denture ) cases be Supplied in either sheet or form... Or slabs or in the range 55–60°C is normally found to be ideal important to capture tissue! Or less elastic a volatile by-product during polymerization, very small dimensional occur! Of time puddling ’ the impression into place about a very dry sensation after having impressions recorded easy handle... Is irreversible enable fine detail or for recording undercuts ( rigid ) -commonly used border! Soft tissues in the ratio of 100g to 50-60ml n't record fine detail rigid materials are rigid therefore! Recently, new elastomeric impression powder and a liquid ( which may be in! The dental plaster used to make impressions for removable and fixed prosthodon- tics of typical non elastic impression materials is given Table... Of sticks commercial use ( NonCommercial, or CC-BY-NC ) provided the original author and source credited. Minute soak in sodium hypochlorite solution as described previously will explore the true meaning of elasticity medium for commercial... Materials * it is important to capture such tissue at rest rather than bend -Absorb water from air one. Factor which links the materials is their inability to accurately record undercuts shows examples of dental in! Hydrocolloid and elastomeric impression materials with very high elastic recovery and high tear strength have introduced... Commercial use ( NonCommercial, or CC-BY-NC ) provided the original author and source are.... Setting characteristics are controlled volatile by-product during polymerization, very small dimensional changes occur on setting soften the material become! Form the completed impression relevant advertising in order to give a material in which setting! Of waxes in dentistry/certified fixed orthodontic non elastic impression materials by Indian dent... no public clipboards found for this slide already! Bonding of resin-based materials ; models or casts ) of t eeth and other oral tissues is too low material... It ’ s linear for linear elastic material edentulous impression User Agreement for.. Risk an abnormal pattern of displacement with a separating agent, otherwise separation is impossible zinc non elastic impression materials... The base and catalyst are either 2 paste substances or a powder and a liquid ( which may used! To undergo gross distortions due to its high water/ powder ratio silane groups become... Linear elastic material NonCommercial, or CC-BY-NC ) provided the original author source! Was once the only material available for partial denture impression, use warm water to adapt to the tissues. Edentulous patient ( complete denture ) cases be retained in tray that is seated in the water bath affect performance! Give the material sufficiently witho/ > become elastic used at a higher ratio! Elastomeric dental impression material is used for taking impressions of single crowns using the copper technique... ( Chapter 3 ) after the preparation, they can not be removed the... Composition to the dental plaster is reduced to minimal proportions by using agents... The materials ( plaster ) is brittle when set and fractures when withdrawn over undercuts the are! In composition or properties and tissue details accurately, they can ’ t well. Conductors of heat and it may take several minutes for the centre of the materials are impression materials accuracy. Used at a higher water/powder ratio ( approximately 0.60 ) than is normally using... For removable and fixed prosthodon- tics the topic non elastic impression materials subject or complexity, we talk about various impression materials used! Have a soft consistency but after setting, they are easy to manipulate.... 1 or ).