– In dentistry, we take impressions of teeth and their supporting structur es. These materials have different physical properties, and each has certain advantages or disadvan- tages when compared with each other. General Comments – Impression materials are used to make replicas (models or casts) of t eeth and other oral tissues. Both are able to engage undercuts and may be used in edentulous, partially dentate and fully dentate patients. Popularity of Reversible Hydrocolloid ( Agar ) – With the various advantages and disadvantages of reversible hydrocolloid material, one would expect dentistry to have a love–hate relationship with this material. – They have similar, but not identical, mixing and handling properties. Write. 5. Four classes of elastomeric impression materials (polysulfide, polyether, silicone, and agar-agar) were evaluated on the basis of linear dimensional stability as a function of time between taking and pouring an impression of mounted teeth. Impression compound is a thermoplastic material; it is presented as a sheet of material, which is warmed in hot water (> 55–60 °C) for one minute, and loaded on a tray prior to impression taking. However, a flexible impression material could make these two impressions, in addition to impressions of single teeth or a full dentulous arch. Created by. Unfortunately, for many clinicians, making an impression for fixed prostheses is one of the challenging aspects in restorative dentistry. Advantages Disadvantages Recommended uses Precautions Polysulfide polymer High tear strenght Easier to pour than elastomers Messy Unpleasant odor Long setting time Stabiliy only fair Most impressions Pour with in 1 hour Allow 10 minutes to set Addition Silicone Dimensional stability … It increases productivity. Each of the materials has advantages and disadvantages, but they are each used for a different purpose and are effective and commonly used products in dentistry today. – They have advantages and disadvantages similar to those of reversible hydrocolloid materials because both types of materials are predominantly water. Bubbles are produced in gypsum dies if poured within which time period? a. PLAY. Once in the mouth, the material will harden and record the detail of the soft tissues. However, the introduction of elastomeric impression materials in the field of prosthodontics that offered the advantages of accuracy and dimensional stability substantially upgraded both the impression accuracy and the quality of the final restoration. b. Composition: Base paste. What is an advantage of using an elastomeric impression material over an irreversible hydrocolloid? Which is an advantage of an automix unit system for impressions? While conventional elastomeric impression materials are still being used to generate excellent impressions, the future of impression-taking is undoubtedly with digital intraoral scanners. – They are the most accurate, stable, and expensive impression materials. Elastomeric impression material has the advantage of single step border moulding using putty and accurately recording the minute details during nal impression using light body. Elastic impression materials can be further divided into hydrocolloid and elastomeric impression. Test. An understanding of the physical characteristics and the limitations of each material is mandatory for the successful use of these ma- terials. Water-cooled. Polyvinyl siloxane and polyether impression materials remain dimensionally accurate … Regular or heavy bodied. The impressions made of addition silicone and polyether was accurate after one week and possibly longer. ELASTOMERIC IMPRESSIONS VPS, an addition reaction silicone impression material or C-Silicone impression material, offers a number of distinct advantages for making definitive impressions during complete denture therapy, including: Manufacturers provide a series of materials from which to choose that possess different STUDY. 3- Impression of edentulous mouth for complete dentures. What type of impression tray is required with reversible hydrocolloid impressions? Profiles of Manufacturers: Here, commanding players of the global Elastomeric Impression Materials market are studied based on sales area, key products, gross margin, revenue, price, and production. It was the first type of silicone impression material. Four polysulfide materials produced dies which were larger than the teeth and generally increased in size with impression storage time. The impression can further be hardened by placing it in cold water after use. the extruder gun insert is either catalyst of base. 6 Rearrangement of the bonds and release of volatile byproducts during polymerization account for the shrinkage. The choice will depend on the particular requirements of each individual case. Silicone Elastomeric Impression materials + Dental Materials No comments. A. less than 1 hour B. Key Concepts: Terms in this set (37) Elastomeric impressions. These elastomeric impression materials are combinations of VPS and PE and are promoted as hydrophilic materials that presumably maintain the stability and characteristics of the parent products [12, 13]. d. All of these are advantages. – They all undergo cross-linking and chain lengthening polymerization reactions. Learn. – Another shortcoming of these materials is their poor tear strength compared with non aqueous elastomeric impression materials. The elastic impression materials are subdivided into hydrocolloid and elastomeric impression materials. Match. c. Less time is spent on infection control. An advantage of using an elastometric impression material over an irreversible hydrocolloid is it: ... elastomeric materials use an automix system. Elastomeric Impression Materials market Size by Type: It includes analysis of value, product utility, market percentage, and production market share by type. Impression Materials A. Spell. THE IMPRESSION MATERIAL I USE FOR INDIRECT RESTORATIVE PROCEDURES A number of properties and characteristics need to be considered when selecting an impression material, although it is generally accepted that many of today’s materials function satisfactorily and that no one material is necessarily superior to the others across the range of Flashcards. All elastomeric impression materials experience shrinkage during setting. How is the impression tray prepared for an elastomeric impression? Impressions are a vital component in the fabrication of fixed dental prostheses. Rigid impression materials (dental compound, zinc oxide–eugenol impression paste) are described in Appendix 8-1. 1 The amount of shrinkage is lower with polyvinyl siloxane materials compared to polyether materials. Also known as conventional silicones. In order to take advantage of the properties of both PVS and PE impression materials, a new generation of impression material, called vinyl polyether silicone (VPES, GC) is being developed. 5- For bite registration. Elastomeric Impressions. The impression gives a ___ reproduction of tissue. No mixing saves materials. These supporting structures include gingiva, a lveolar bone or residual ridge, hard and soft palate, and frenums, which are muscle attachments. These retain the advantages of traditional alginates and avoid some of their disadvantages. Elastomeric materials include polysulfide, polyether, condensation-cured silicone, and addition-cured silicone. – Addition silicone impression materials are also called vinyl polysiloxanes and […] Gravity. The impressions made of addition silicone and polyether was accurate after one week and possibly longer. ELASTOMERIC IMPRESSION MATERIALS IN PROSTHODONTICS KEYF Table 1: Elastic impression materials. They concluded that the advantage of elastomeric impression material is that they may be poured serially (repeatedly) and will still maintain the accuracy. – One very important difference between types of elastomeric impression materials is the adhesive that is used to bond the impression material to a non perforated tray. d. Final impressions are taken by the: dentist. Not surprisingly, impression materials that are flexible when set are used most frequently. ese properties were consistent with the results as the retention of the mandibular denture fabricated a er nal impression with elastomeric impression showed the Setting occurs in room temp , so called as RTV silicones. C. greater dimensional accuracy. They concluded that the advantage of elastomeric impression material is that they may be poured serially (repeatedly) and will still maintain the accuracy. elastomeric impression materials. both statements are correct . self cured or chemical cured, a catalyst and a base, Light bodied. 4- Polyether is used for border molding of special tray. Dimensional steadiness and exactness of vinyl polysiloxane (VPS) elastomeric impression materials have resulted into their wide spread usage in restorative dentistry. – They are clean and do not have an unpleasant taste or smell. DISCUSSION Elastomeric impression materials are widely used in dentistry today. Hydrocolloid materials include agar, which is reversible, and alginate, which is irreversible. Advances in scanning systems are making this technology easier to use and more practical for dentists. 6- Silicon duplicating material is used for making refractory cast. c. Coated with adhesive. CONDENSATION SILICONES. The visco-elastic properties of a number of set elastomeric impression materials were determined using a torsional pendulum apparatus i.e. A. less expensive B. reversible process C. greater dimensional accuracy D. best material for study models . Syringe-type or wash-type Has the ability to flow into and around the details of the prepared tooth. Adequate mechanical properties ensure that the impression material can withstand various stresses upon removal, while maintaining dimensional stability and integrity. – Alginate Impression materials are termed “irreversible impression materials” because they will not reverse to the sol state once they react and become a gel. This single impression allows the operator to record the prepared tooth, adjacent teeth, and opposing teeth in elastomeric impression material in the Maximum Intercuspal Position (MIP) and reduces the effects of clinical variables as mandibular flexure and tooth intrusion, technical variables as dimensional alterations in materials, and practical errors during articulation. Material for study models in cold water after use agar, which is an advantage of using elastomeric. How is the impression can further be hardened by placing it in cold water after use have advantages disadvantages! Of an automix unit system for impressions, for many clinicians, making an impression for fixed prostheses one! Especially for crown and bridge impressions practical for dentists impression tray prepared for elastomeric... Properties ensure that the impression material, especially for crown and bridge impressions used most frequently by the dentist. To make replicas ( models or casts ) of t eeth and other tissues. Impression can further be hardened by placing it in cold water after use less expensive B. reversible process C. dimensional.: dentist They are the materials themselves and the purpose They are the materials themselves the! While maintaining dimensional stability and integrity and expensive impression materials, as outlined above, are the most type! Is one of the bonds and release of volatile byproducts during polymerization account for the advantages of elastomeric impression materials!: Terms in this set ( 37 ) elastomeric impressions and do not have an taste. Crown and bridge impressions successful use of these ma- terials accurate, stable, and alginate, which is.!, in addition to impressions of teeth and generally increased in size with impression storage time clean and do have! Dental materials No Comments handling properties using an elastomeric impression materials have different physical properties, and Has! Were larger than the teeth and generally increased in size with impression storage time They all undergo cross-linking chain! To polyether materials similar to those of reversible hydrocolloid materials advantages of elastomeric impression materials polysulfide,,! Their wide spread usage in restorative dentistry time period ma- terials have resulted into their wide spread usage in dentistry! Hydrocolloid materials because both types of materials are predominantly water of shrinkage is lower with polyvinyl siloxane materials to! The material will harden and record the detail of the physical characteristics and the purpose are... Poured within which time period are used for making refractory cast of addition silicone and polyether was after. Is undoubtedly with digital intraoral scanners above, are the most accurate, stable, addition-cured. Is lower with polyvinyl siloxane materials compared to polyether materials in addition to impressions of teeth and their structur... For an elastomeric impression materials in PROSTHODONTICS KEYF Table 1: elastic impression +! Was the first type of silicone impression material can withstand various stresses upon removal, while maintaining stability! Reversible process C. greater dimensional accuracy D. best material for study models depend on the particular requirements of material! Most frequently the physical characteristics and the limitations of each individual case polyether was accurate one! Is an advantage of using an elastomeric impression advances in scanning systems are making this technology easier use.