Silicones are the most dimensionally stable of all the materials and will keep their shape even if left for long periods. However, silicones work best in a dry environment and may not be ideal if there is a lot of saliva. Alginate is flexible and flows well. This allows the impression material to record fine surface detail. However, alginate does have poor dimensional stability and will distort if left to dry or left in water for too long. - Dr May Ali Soh G, Chong Y H . Defects in automixed addition silicone elastomers prepared by putty-wash impression technique. J Oral Rehabil 1991; 18: 547–553. Cha HS, Kim JW, Hwang JH, Ahn KM. Frequency of bone graft in implant surgery. Maxillofac Plast Reconstr Surg. 2016;38(1):19. doi: 10.1186/s40902-016-0064-2 Hondrum S O . Tear and energy properties of three impression materials. Int J Prosthodont 1994; 7: 517–521.

Practical application of the newly introduced natural bone regeneration (NBR) concept utilizing alloplastic putty. Kotsakis G, Chrepa V, Katta S Int. J Oral Imp Clin Res Sept-Dec 2011; 2(3):145-149. Use of the NovaBone augmentation material in the treatment of chronic periodontitis. Preliminary communication. Slezak R, Paulusova V., ACTA MEDICA (Hradec Kralove) 2013:56(4):157-161.Our dental impression materials have passed FDA, 510K, CE, simple operation, good flexibility, and can print a complete and clear impression. Your healthcare provider will then electronically deliver your photo files to a dental lab. There, a technician will begin working on your case. How long does a dental impression take? Enough powder has been incorporated for a base consistency when the mix “flakes” from the spatula when pressing on the cement. Generally, polyether and VPS impression materials are suitable for making impressions of natural teeth and implants. Due to the higher initial hydrophilicity and constant flow behavior of polyethers, they may show a superior reproduction of the relevant details, especially in more complex cases where extra working time is needed. Based on this assumption, they are often preferred in clinically challenging situations and recommended for implant cases with multiple units. Our recommendation is that if a VPS impression material is used, the clinician should select a product, which is hydrophilic already in the unset state and offers good flow properties; e.g. 3M™ Imprint™ 4 VPS Impression Material.

In the process of impression preparation, the surgeon should fully reflect the love-intention consciousness, try to eliminate the patient's nervousness, gentle movement, correct posture, avoid irritating the pharynx and cause nausea, avoid tray compression, damage the oral tissue, and ensure patient comfort and impression quality. Comparative evaluation of bioactive glass putty and platelet rich fibrin in the treatment of human periodontal intrabony defects: a randomized control trial. Naqvi A, Gopalakrishnan D, Bhasin MT, Sharma, N, Haider K, Martande S. J of Clinical and Diagnostic Research 2017 Jul, Vol-11(7): ZC09-ZC13. It has a limited working time based on the temperature of the water used and it is available in both standard and fast-setting varieties. An alternative approach is to inject the wash material around the preparation and then immediately seat the tray with freshly mixed putty over the wash material. However, this approach risks displacing too much wash material by the putty, so that a critical area of the preparation is reproduced in the putty without the required detail. Occlusal stops should be used in the tray to avoid having the teeth penetrate through the wash or syringe material when the plastic putty mass is being seated. There are four main types of impression material that are routinely used in dentistry. They can be categorised into either rigid impression materials (zinc oxide eugenol and impression compound) or elastic impression materials (alginate and silicone). Each material is used for different purposes, as some laboratories require a more detailed impression than others. Impression materials are commonly classified by their elastic properties once set. Non-elastic materials are generally not used for taking impressions of crown preparations because of their inability to accurately record undercuts.Fenske C. The influence of five impression techniques on the dimensional accuracy of master models. Braz Dent J. 2000;11:19-27. Its accuracy can be improved by retaking the impression. This is done by adding fresh paste and inserting into the mouth until set. American National Standards Institute and American Dental Association. ANSI/ADA Specification No. 19: Dental Elastomeric Impression Materials. Chicago, Ill: American Dental Association, Council on Scientific Affairs; 2004. Wadhwani CP, Johnson GH, Lepe X, et al. Accuracy of newly formulated fast-setting elastomeric impression materials. J Prosthet Dent. 2005;93:530-539.

The rigid materials are usually used to record impressions of edentulous arches only. Impression compound must be heated in a water bath and then moulded onto the impression tray. It doesn’t flow well and can't record fine detail. It is therefore used for primary impressions of edentulous arches. Impression paste is a modified form of zinc oxide eugenol. Other properties are added to make it suitable to use as an impression material. It comes in two tubes: one containing a white zinc oxide mixture and the other containing a red eugenol mixture. When using this product equal amounts of each paste should be squeezed onto a pad and mixed with a spatula. The mix should then be loaded into a special tray for secondary impressions of the edentulous arch. When the products are mixed together they will create a different colour; there should not be any red or white streaks remaining. The various cements, bases, and liners used in restorative dentistry are discussed in detail in Chapter 7, Dental Cements. The discussion covers the use, composition, and physical as well as chemical properties of each material. As stated earlier, these materials can be used as base or lining agents, luting materials, or permanent or temporary restorations. This chapter focuses on the manipulation of some of these commonly used materials. I.PurposeCarrotte P V, Johnson A, Winstanley R B . The influence of the impression tray on the accuracy of impressions for crown and bridge work – an investigation and review. Br Dent J 1998; 185: 580–585.