Fast Setting Dental Impression Putty

Product Information

Glass ionomer cement may be used as a base, a luting agent, or a restorative material. As a luting agent, it is used to permanently cement crowns, bridges, and orthodontic bands. As a base, it is used as a thermal insulating material in deep cavity preparations. B.Related Information The difference between luting consistency and base consistency is that a higher powder/liquid ratio is used for base consistency. This means that fewer drops of liquid will be needed to mix the cement for a base consistency. The specific amounts to be used are provided by the manufacturer. 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. A simplified approach to the minimally invasive antral membrane elevation technique utilizing a viscoelastic medium for hydraulic sinus floor elevation. Kotsakis GA, Mazor Z. Oral Maxillofac Surg. 2015; 19(1): 97-101. The powder is also divided into increments for base consistency, but this may include the division of one powder increment into yet smaller increments.

Wadhwani CP, Johnson GH, Lepe X, et al. Accuracy of newly formulated fast-setting elastomeric impression materials. J Prosthet Dent. 2005;93:530-539. When making dental impressions, your healthcare provider may use traditional dental putty or digital dental impressions. While the outcomes are similar, the procedures are different. Traditional dental putty Objective: Oral rehabilitation success is enhanced by an accurate and reproducible final impression. The purpose of this study is to evaluate the dimensional changes of a polyether and addition silicone subjected to disinfection and/or sterilization after a long storage period. There is no single procedure that a dentist can do, or any single procedure that a lab can do for the dentist, that will improve the final result of indirect restorations more than improving the quality of the impression. The impression is the basic starting point for all laboratory procedures, as well as the basis for quality and cost-effective dentistry for the clinician. Alginate impressions must not be soaked for too long in a water-based disinfectant and should be cast up as soon as possible to avoid shrinkage leading to inaccurate dental work.

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With the elimination of the putty viscosity as a recommended choice, the remaining choices are heavy-body, light-body, and monophase materials. To logically choose the best to use, it is important to consider how all materials react during setting and the impact that has on the previous discussion of trays and techniques.

There are primarily two material classes that are widely accepted for precision impressions: Polyethers and A-type (addition-cured) silicones (VPS). Due to their low cost, C-type silicones (condensation-cured) are also still being used in some dental practices. However, their material-inherent high polymerization shrinkage leads to an inferior dimensional accuracy of the impression and therefore their use is not recommended for precision work. No reaction by-products are formed as long as the correct proportions of divinylpolysiloxane and polymethylhydrosiloxane are used and there are no impurities. However, the residual polymethylhydrosiloxane in the material can lead to a secondary reaction with each other or with moisture, to produce hydrogen gas. Technically, hydrogen gas is a reaction by-product that does not affect the dimensional stability of the impression. Nonetheless, the hydrogen gas evolved can result in pinpoint voids in the gypsum casts poured soon after removal of the impression from the mouth. Manufacturers may add a noble metal, such as palladium, as a scavenger for the released hydrogen gas. The impression should be left overnight if epoxy will be used for pouring models. A-type silicones – also known as VPS impression materials – are hydrophobic (i.e. water-resistant). By the addition of surfactants (wetting agents), it is possible to increase the material’s hydrophilicity even in the unset state. In addition, there are great variations of the flow behavior during the working time offered by different materials with a flow reduction seen especially towards the end of the working time. General advantages of VPS are their superior elastic recovery, high dimensional stability over time, and neutral taste.The base paste, is a polysulfide polymer that contains a multifunctional mercaptan (-SH) called a polysulfide polymer, a suitable filler (such as lithopone or titanium dioxide) to provide the required strength, a plasticizer (such as dibutyl phthalate) to confer the appropriate viscosity to the paste, and a small quantity of sulfur, approximately 0.5%, as an accelerator. The catalyst (or accelerator) paste contains lead dioxide, filler, and plasticizer as in the base paste, and oleic or stearic acid as a retarder to control the rate of the setting reaction. Lead dioxide is the component that gives polysulfide impression material its characteristic brown color. The terms catalyst and accelerator used here and with other impression materials are actually misnomers. Reactor is a more appropriate term for the reactions associated with polysulfide and other types of impression materials. Another study evaluated the effect of the viscosity of the impression materials in plastic and metal dual-arch trays.2 There were statistically significant differences noted in the accuracy of the dies. Rigid materials in metal trays were the most accurate, while monophase materials in plastic trays produced dies that were dramatically shorter.

Fenske C. The influence of five impression techniques on the dimensional accuracy of master models. Braz Dent J. 2000;11:19-27. It doesn’t take long for a piece of tooth, or old restorative material to get caught between the diamond grits in a bur.Dietschi, D. 2007. The natural layering concept: a breakthrough in free-hand bonding techniques. Aust. Dent. Pract. 18: 158– 165.

A taper of between 10° and 20° is usually adequate and achievable. In reality this means a preparation that is as parallel as you can make it, without any undercuts. Do your best to control these by using retraction cord, haemostatic agents, or possibly even surgery (electrosurgery, or crown lengthening surgery) to give you a clear, clean field. Impression materials are introduced into the mouth as viscous pastes with precisely adjusted flow properties. The viscosity and flow behavior of the unmixed components are also important in regard to the ease of mixing, air entrapment during mixing, and the tendency for the trapped air to escape before the impression is made. After the impression material has completely solidified, gently tilt the tray to dislocate the impression and then rotate the tray out of the mouth. Avoid violent use when removing the impression, avoid excessively tilting the tray, to avoid deformation of the tray and the impression, or to release the impression material, to avoid the tray rubbing against the jaw or damage the soft tissue.

Monophase materials are limited in their clinical application. An ideal material must be resilient enough to be withdrawn from the mouth easily, particularly when mobile teeth or prepared teeth are thin. The material must also be flexible enough to be removed from the model without breaking off a thin preparation. This has ledto the development of the “soft” formulas of polyethers. However, any material when used in a sideless, dual-arch tray must be firm enough to support the weight of the gypsum when the model is poured, without sagging under the weight of the stone. It appears that one viscosity of material would not be able to ideally fulfill all of these parameters simultaneously.