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jan 11

non elastic impression materials

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

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