Dental impressions are a common procedure used in dentistry, but if you are one of the many patients that absolutely can't stand to have the traditional impression material sit in your mouth, you will be glad to know that yes, there is an alternative.
Digital impression systems, such as the Lava Chairside Oral Scanner by 3M, the CEREC AC by Sirona, and the Cadent iTero system, are used to take a digital "impression" of the teeth, rather than use the traditional gooey impression material that is necessary to obtain the final impression for a crown, bridge, or veneer.
Dr. Leonard Tau of The Pennsylvania Center for Dental Excellence introduced the Cadent iTero system into his general dental practice, and has noted some positive results. "It eliminates the goopy dental impression material that causes patient to gag and not enjoy their visit," says Dr. Tau. "It also allows for a better-fitting final restoration, which in turns allows for a faster appointment and the patient thus spends less time in the dental chair."
When your dentist has completely prepared the teeth that require restoration, a wand is used to take a digital image of the teeth. According to Dr. Tau, taking a digital impression of prepared teeth takes approximately a minute and a half, and an impression of the teeth in the opposite arch takes a mere 45 seconds.
And how accurate is iTero? Very, says Dr. Tau. "The iTero digital impression system creates an exact replica of what is in your mouth. This results in a more accurate-fitting crown or bridge. I have never had restorations that have fit better."
However, researchers are still looking into the technology's effectiveness. An article published in 2008 in the Journal of the American Dental Association (JADA) determined that digital impression systems are a promising technology, but additional research is still necessary in order to fully distinguish the pros and cons between the two impression-taking methods.
One of the most common areas of concern when creating a crown, bridge, or veneer involves the tiny space between the tooth and the gum tissue that surrounds the tooth (known as the subgingival margin). Without an accurate imprint of this area, the final restoration may not fit the tooth appropriately, resulting in a myriad of problems down the road. The JADA paper notes that digital impression technology won't necessarily improve the final impression's outcome, and there is still a need for the most careful isolation of the soft tissue prior to taking the digital impression.
Keep in mind that not every dentist utilizes this type of digital impression technology. Some dentists prefer to use the traditional impression-taking methods because the cost of digital technology is very high. Others prefer to use traditional impression methods because of the lack of research that proves digital impressions are superior.
On the other hand, some dentists that have switched to digital impression systems would never consider turning back. According to Dr. Tau, "[My] patients love the iTero, especially the patient who cannot take a dental impression due to a severe gag reflex. If you have ever had a conventional impression taken, you know just how uncomfortable the process is. The putty is messy, tastes extremely unpleasant, and in many patients can cause gagging."
Patients interested in learning more about digital impression systems should speak to their dentist about this technology.
Interview with Dr. Leonard Tau of The Pennsylvania Center for Dental Excellence. November 18, 2009.