Intraoral Scanners Have Arrived
The annual session of the AAO is always the highlight of myprofessional year. It's a chance not only to meet old friends and colleagues,but to make new friends and greet the up-and-coming members of the specialty.The lectures and continuing-education opportunities are generally rewarding,and this year's session in Philadelphia was especially good. But while thescientific presentations serve to introduce and evaluate new orthodontictechniques, it is the manufacturers' exhibits that give us a hands-on try at what'snew. For all of us who fall into the experiential learning camp, this allows usto learn about and critically appraise the new products being brought tomarket.
Every few years, one new technology or another seems todominate the exhibits. Almost a decade ago, it was cone-beam computedtomography (CBCT). To hear it told on the exhibit floor, CBCT would be the onlyway to evaluate patients radiographically in what was then portrayed as the"near future". Consequently, almost every graduate orthodontic programin the country obtained a cone-beam machine. After a few years, however,everybody noticed that we changed next to nothing about the way we diagnosedand treated most patients, and the pendulum swung back toward the time-testedtwo-dimensional cephalometry and panoramic radiography. The added expense ofCBCT and concerns (whether factual or not) about increased radiation exposureseem to have been the driving factors.
If you recall, the previous big thing on the technologyfront had been temporary anchorage devices (TADs, or miniscrews). This was theoverriding theme for a few annual sessions; at the time, it seemed that almostevery other article we received for consideration in JCO involved the use ofminiscrews. Unlike CBCT, even though the initial excitement seems to havepeaked, TADs have gone on to become mainstream tools in our clinicalarmamentarium.
This year, the rage at the annual session was intraoralscanners. When I heard several manufacturers' representatives assert that thesescanners would replace impressions in the near future, I was reminded of theclaims being made about CBCT not long ago. There is no doubt that intraoralscanners are a promising technology. They do indeed resolve the age-old dilemmaof how to store the thousands of study models accumulated over the life span ofany practice. Based on evidence presented by the manufacturers, the imagesgenerated by intraoral scanners seem to be as accurate as the study modelsproduced from polyvinyl siloxane impression material. These images can beinterfaced with other computer-driven technologies, such as aligners andfull-facial digital renderings-- opening up amazing possibilities with respectto our diagnostic views of a patient¢s entire orofacial complex. What's more,the technology satisfies the cravings that many of us have for cool newgadgets.
I spent a substantial amount of time in Philadelphiachecking out the various scanners that are currently on the market. They seemto differ in two major areas: first, whether a powder is applied to the teethprior to the scan, and second, the size of the intraoral portion of the scanneritself. Some companies offer online "cloud" storage of the imageswith monthly data fees, similar to mobile-phone plans but much more expensive.Others provide downloadable images that can be stored on servers in individualpractices.
Although I watched several apparently experienced andskilled assistants take scans in a reasonable amount of time, there is adefinite learning curve involved in using these devices. Because there is nosimilarity whatsoever to taking an impression, I had no transferable prior knowledge.The quickest I could scan an entire arch was about 20 minutes. Admittedly, I aman old dog trying to learn new tricks, but this seemed a little excessive tome. The other major issue with intraoral scanners is their cost. The leastexpensive I could find ran between $15,000 and $20,000 for the equipment, withongoing service and data plans for about $400 per month. That would buy a lotof alginate, model storage issues aside.
The next couple of years will tell the tale of intraoralscanners. I expect that they are here to stay, especially considering theirability to interface with other digital technologies in orthodontics, oralsurgery, and restorative dentistry. If the past is the best predictor of thefuture, however, I expect to see their use increase substantially and peakfairly soon, followed by a gradual decline to a baseline level of acceptance.
Here at JCO, we welcome the submission of rigorousindependent studies of the efficacy of intraoral scanners. I look forward towhat the next few years will bring.