In First Impressions George Freedman, DDS, gives readers a brief summary of products that have recently been introduced to dentistry, based on his clinical experience.
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Pola Day CP |
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Impressiv |
 The most likely cause of an inadequate polyvinyl crown or bridge impression is moisture interference during the polymerization phase. Most impression materials are hydrophobic and mandate that they must be used in a dry environment. While the practitioner may be very conscientious about drying the oral cavity prior to taking the impression, it is inevitable that moisture contamination will occur at the worst possible of all areas, the preparation margin. This is due to the continual flow of crevicular fluid into the sulcus; the dryer the gingiva, the faster the flow rate. Thus, the attempt to totally dry the target impression site is futile from the beginning. Fortunately, true hydrophilic impression materials are available. Cosmedent’s Impressiv is a new hydrophilic addition-curing silicone impression system that works in a wet environment. Its indications include crowns, bridges, veneers, inlays, onlays, and implant restorations. Impressiv’s chemistry provides for excellent adaptation to the most minute preparation anatomy and superior tear strength that guarantees stress-free removal from the mouth. The impression may be poured 60 minutes after the start of the mix but may also be delayed for up to 14 days without any loss of accuracy. The impression can be disinfected in a 2% gluderaldehyde solution for 15 minutes at the laboratory. Impressiv’s working time is 2 minutes 15 seconds, and total set time (including the working time) is 5 minutes. There are 2 dispensing options: a 1:1 hand gun automix and a 5:1 machine automix. Latex (ie, gloves and other dental paraphernalia) interferes with the polymerization of this material. Impressiv is a true hydrophilic impression material that eliminates the stress of trying to dry. For more information, call (800) 621-6729 or visit the company Web site at cosmedent.com. |
Dr. Freedman is a founder and past president of the American Academy of Cosmetic Dentistry, a co-founder of the Canadian Academy for Esthetic Dentistry, and a Diplomate of the American Board of Aesthetic Dentistry. He is a visiting professor at the Universita di Firenze, Florence, Italy. He is the materials editor for Dentistry Today. He is the author or co-author of 11 textbooks, more than 600 dental articles, and numerous webinars and CDs, and is a team member of REALITY. He lectures internationally on dental aesthetics, adhesion, desensitization, composites, impression materials, and porcelain veneers. A graduate of McGill University in Montreal, Dr. Freedman maintains a private practice limited to aesthetic dentistry in Toronto. He can be reached at (905) 513-9191 or epdot@rogers.com.
