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. -Must be stored in an airtight container . Any excess material is removed from the window and the impression re-seated in the mouth. Dentaljuce and Prosthodontics - this should go together well. Rigid impressions (impression compound & zinc oxide eugenol) The rigid materials are usually used to record impressions of edentulous arches only. The stick material is used for border extensions on impression trays or for recording impressions of single crowns using the copper ring technique. It is therefore used for primary impressions … Are those that set to a rigid consistency . Before casting a plaster model in a plaster impression, the impression must be coated with a separating agent, otherwise separation is impossible. Dental amalgam;. Compound 3. the material is non-elastic, so cannot be used in undercut areas. The plaster should be mixed with water or an anti-expansion solution in the ratio of 100g to 50-60ml. If the conditioning temperature is too low the material does not soften properly, and if too high, it becomes sticky and unmanageable. 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 2.2. The tray may be constructed from acrylic resin or shellac. -Very rigid and will break rather than bend -Absorb water from air. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. 4. 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. They are easy to handle and their accuracy is pretty good. Plaster of Paris . 17.1) is a thermoplastic material, having properties which in many ways are similar to those of the dental waxes discussed in Chapter 4. The anti-expansion agent, retarder and pigment are incorporated into the impression plaster powder by some manufacturers. Elastic impression materials 1. Is steel more elastic than rubber? As an alternative an anti-expansion solution, containing potassium sulphate, borax and pigment, may be prepared and used with a standard white plaster. How do we say whether something is more or less elastic? 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. Regardless of the topic, subject or complexity, we can help you write any paper! Looks like you’ve clipped this slide to already. It can undergo virtually no compressive or tensile strain without fracturing. Following setting, the plaster impression material is very brittle. If you continue browsing the site, you agree to the use of cookies on this website. While in the mouth they set in a reasonable amount of time. They are classified together for convenience rather than for reasons of similarity in composition or properties. The sheet material is normally softened using a water bath. 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 water-absorbing nature of these materials often causes patients to complain about a very dry sensation after having impressions recorded. Rigid / Inelastic. Viscous enough to be retained in tray that is seated in the mouth 3. A temperature in the range 55–60°C is normally found to be ideal. The composition varies from one product to another but an indication of typical composition is given in Table 17.1. These impression materials are rigid and therefore exhibit little or no elasticity. Fig. 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 … BDS. An impression of the bulk of the ridge is recorded in zinc oxide/eugenol paste. See our Privacy Policy and User Agreement for details. 19 B. Non-Elastic Impression Materials. You can change your ad preferences anytime. Agar may be used but as discussed has a number of technical difficulties in its use. The setting expansion of dental plaster is reduced to minimal proportions by using anti-expansion agents. Addition silicones (polyvinylsiloxanes) have a moderately low-molecular weight silicone that contains silane groups. Elastomeric materials include polysulfide, polyether, condensation-cured silicone, and addition-cured silicone. ZOE. 1. Impression types; Non-Elastic Materials; Prosthodontics. Ideal Properties of Impression Materials *It is easy to manipulate.... 1. 2.1.2.1. – In dentistry, we take impressions of teeth and their supporting structur es. After the preparation, they are placed inside impression trays. One of the materials (plaster) is brittle when set and fractures when withdrawn over undercuts. Compound impression can be added or corrected. Adhesive restorative materials: bonding of resin-based materials;. The mixed impression material is initially very fluid and is capable of recording soft tissues in the uncompressed state. A comparison of elastic impression materials James A. Stackhouse, JrD.D.S., M.S. 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. Elastic impression materials. -It can be used as a "wash" (a thin lining material placed over stiffer base material) for edentulous impression. Another technique is to record the plaster impression as a wash in a preliminary compound impression. Non-elastic Materials 2.1. Check out this awesome Our Research Papers About Dental Impression Materials for writing techniques and actionable ideas. 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. The type I materials are impression materials whereas the type II materials are used for constructing impression trays. 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). Fluid enough to adapt to the oral tissues 2. 2. 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. Rigid or non elastic materials classification, types properties etc. MHR. Any significant deformation produces a permanent deformation. 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). They can’t record the undercut area It consists of calcined, β-calcium sulphate hemihydrate which when mixed with water reacts to form calcium sulphate dihydrate. 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. It is capable of recording tooth and tissue details accurately , they cannot be removed from the mouth without fracture and reassembly . Elastic impression materials: Synthetic elastomers;. 6. This definition also implies that the constitutive equations are spatially local. Now customize the name of a clipboard to store your clips. impression materials (non-elastic) STUDY. 2.1.2. 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. Non elastic impression materials ASST PROFESSOR Dr Mumtaz ul Islam B.Sc. Key Words : Elastic impression materials, accuracy, dimensional stability. 1. 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. They are used mainly for edentulous patient (complete denture) cases. A brief introduction Dr saransh malot Impression materials. (4) Zinc oxide/eugenol impression pastes. The material is weak and easily fractured due to its high water/ powder ratio. 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. With other materials the tray is simply seated home in a single movement. # The American Dental Association (ADA) specification number for non aqueous elastomeric dental impression material is : A. 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. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. -Plaster of paris is seldom used as impression material. Zinc Oxide Eugenol 4. The materials are poor conductors of heat and it may take several minutes for the centre of the material to become softened. 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. Impression plaster is similar in composition to the dental plaster used to construct models and dies (Chapter 3). 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. General Comments – Impression materials are used to make replicas (models or casts) of t eeth and other oral tissues. reproduction in any medium for non commercial use (NonCommercial, or CC-BY-NC) provided the original author and source are credited. Elastic. Resin-based filling materials;. 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. 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. 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. Non-elastic impression materials;. Impression plaster. See our User Agreement and Privacy Policy. Elastic impression materials can be further divided into hydrocolloid and elastomeric impression. 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. Zinc oxide- eugenol impression paste Supplied in two … The technique for insertion of the impression into the mouth involves ‘puddling’ the impression into place. Non-elastic materials are generally not used for taking impressions of crown preparations because of their inability to accurately record undercuts. Non-aqueous elastomeric impression materials. A measure of skill and experience is required in order to soften the material sufficiently witho/>. ASST PROFESSOR What are non-elastic impression materials *Develop post WWiII. In this video, we talk about various impression materials including agar, alginate, polysulfide, condensation silicone, polyether, and PVS. PLAY. 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. Table 17.1 Composition of a typical impression compound material. The fragments are then reconstructed in order to form the completed impression. The conditioning time must also be carefully monitored. impression materials Impression materials A brief introduction Dr saransh malot 2. 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. Requirements of direct filing materials and historical perspectives;. 1. Any significant deformation produces a permanent deformation. The stick material is generally softened using a flame. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. If you continue browsing the site, you agree to the use of cookies on this website. Classification of Elastomeric Impression materials: Till now the elastomeric impression materials are divided into 3 types based on the material used The compound is deliberately moved during setting to create space for the plaster wash. Impression Materials A. Rigid Impression Materials. Elastic impression materials: Hydrocolloids;. Here are the topics. M.Phil. Since addition silicones do not produce a volatile by-product during polymerization, very small dimensional changes occur on setting. But how do we define elasticity? Both the temperature and time of conditioning in the water bath affect the performance of the material. The material is used at a higher water/powder ratio (approximately 0.60) than is normally used for modelling plasters. In this video, we will explore the true meaning of elasticity. … 17.1 This shows examples of dental compound in the form of either flat plates or slabs or in the form of sticks. Impression Waxes Impression Plaster. 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. The properties of impression plasters can be compared with those of model plasters and stones by reference to Table 3.2. Plaster of paris was once the only material available for partial denture impression, but now elastic materials have replaced them. Glass-ionomer restorative materials (polyalkenoates);. Chemical reactions Temperature change Irreversible Reversible Chemical reactions Alginate Agar hydrocolloid Irreversible Elastomers Plaster of Paris Polysulphides ZnO Eugenol Polyethers Condensation silicon Addition silicon 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. It doesn’t flow well and can't record fine detail. examples of non elastic IM-ZOE-plaster impression-compound impression . Dental Impression Compound. These supporting structures include gingiva, a lveolar bone or residual ridge, hard and soft palate, and frenums, which are muscle attachments. * College of Medicine and Dentistry of New Jersey, New Jersey Dental School, Jersey City, N. J. T -L e ests for accuracy and other characteristics of elastic impression materials generally fall into one or more categories. Dentistry INTRODUCTION Historically, various materials have been used to make impressions for removable and fixed prosthodon- tics. The sheet material is used for recording impressions of edentulous ridges, normally using stock trays. 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 material is, therefore, not suitable for use in any undercut situations. We all have some intuition for elastic and non-elastic materials. The lower fusing, type I impression materials may be supplied in either sheet or stick form. MHR. Disinfection of a plaster impression can be achieved with a 10 minute soak in sodium hypochlorite solution as described previously. 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. Non elastic impression materials 1. As stated above, there are times clinically where the accuracy of an alginate impression is not acceptable, particularly for the construction of fixed prosthodontics. Impression compound 2. B.Sc. 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. Impression materials, introduction, classification and requirements, rigid impression materials dental material, Impression materials / dental implant courses by Indian dental academy. 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. Non elastic M.Phil. Abstract This study was conducted to evaluate the methods used for measuring the elastic recovery of various elastomeric impression materials. Two types of impression compound are available. Hydrocolloid materials include agar, which is reversible, and alginate, which is irreversible. The fluid mix is required to enable fine detail to be recorded in the impression and to give the material mucostatic properties. Recently, new elastomeric impression materials with very high elastic recovery and high tear strength have been introduced. 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. Dr Mumtaz ul Islam The base and catalyst are either 2 paste substances or a powder and a liquid (which may be water). BDS. Impression material • Any substance or combination of substances used for making an impression or negative reproduction Non Elastic Impression • They are impression materials which fracture or distort upon removal from the undercut area after setting. Compatible with cast & die materials & does not need separating medium. 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. Impression compound must be heated in a water bath and then moulded onto the impression tray. Elastic materials have a soft consistency but after setting, they become 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. As the material is reversible, it can be re-used, but after sterilization. To separate cast from the impression, use warm water. The other products are likely to undergo gross distortions due to plastic flow if used in undercut situations. A factor which links the materials is their inability to accurately record undercuts. 5. 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. The mix should be a smooth paste, free of air bubbles, which may appear on the surface of the impression leading to inaccuracy. Non-elastic impression materials: Impression plaster Impression compound Zinc oxide eugenol Impression waxes Impression Plaster / Plaster of Paris Composition: Plaster of … Besides, which impression material can be electroplated? They are used mainly for edentulous patient 2/23/2016 17. Elastic impression materials - abhishek kavlekar. 7. It is important to capture such tissue at rest rather than risk an abnormal pattern of displacement with a more viscous impression material. These are usually classified as type I (lower fusing) and type II (higher fusing). Uses of waxes in dentistry/certified fixed orthodontic courses by Indian dent... No public clipboards found for this slide. A retarder, such as borax, is normally incorporated, in order to give a material in which the setting characteristics are controlled. This type of materials is also called simple elastic material. 2.1.1. Clipping is a handy way to collect important slides you want to go back to later. Plaster 2. Impression Plaster 3. Impression materials. 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. It’s linear for linear elastic material (hence the name) and more complex in a nonlinear case. Impression compound (see Fig. The copper ring technique use warm water regardless of the bulk of the topic, subject or complexity we... Hydrocolloid and elastomeric impression materials are generally not used for primary impressions … impression. Placed inside impression trays plaster is reduced to minimal proportions by using anti-expansion agents typical. Complain about a very dry sensation after having impressions recorded of their to! Technique for insertion of the materials is also called simple elastic material ( hence the name ) type. 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