For many, taking accurate, predictable impressions can be challenging, time consuming and costly. Since its introduction to the dental arena, computer-aided design and computer aided manufacturing (CAD/CAM) technology has been largely limited to the realm of the dental technician. Today, thanks to new technologies, CAD/CAM is becoming more clinically prevalent, which not only makes the job easier, but also enables clinicians to be more precise. One technology that is having a huge impact in the dental industry is Cadent’s iTero digital impression system (Fig. 1). This device enables dentists to replace conventional impressions with 3-D, computer-rendered optical scans. 
The following case report describes the advantages of the iTero digital impression system and why it a valued tool in any practice.
Case Report:
A 48-year-old female presented with a large failing 2-surface alloy on #2 and a large failing 4-surface alloy on #3, both requiring full coverage crowns (Fig. 2). Prior to preparation, case information was entered into the iTero system by the assistant for laboratory communication via a built-in keyboard (Fig. 3). The unique aspect of the iTero is that any type or number of restorations can be fabricated from the models. Scanning protocol options allow capture from quadrant, half-arch to full arch and there is no need to powder coat the teeth. For this case, two Emax™ restorations were selected. All information must be selected prior to starting the scanning process via several drop down menus. The option to scan the opposing arch first is a nice feature, as it allows for the auxiliary to scan the opposing while waiting for anesthesia (Fig. 4).
Teeth #’s 2 & 3 were prepared and then isolated using a double-cord technique (Fig. 5). Proper isolation must be achieved, as with standard impression techniques, to enable the optics to clearly define the hard and soft tissues. The scanning process begins with voice and image prompts. The first scan is taken of the occlusal of the preparation (Fig. 6). A built-in air compressor maintains a dry, clear field for image capture via a handheld wand, which has a removable sleeve for single-patient use. Although the wand appears large there have been relatively few problems with access and can be used to the clinician’s advantage to retract soft tissues. The wand is simply pressed against the dentition which aids in image stability.
Each image is captured by the press of a button on a wireless foot pedal (Fig. 7). A preview of the scanned areas appears which enables the clinician to ensure that no areas have been missed. The computer then guides the clinican through a series of scans as well as a virtual bite registration. The number of scans will depend on the scanning sequence selected and the number of preparations. For a single preparation, typically there are 21 scans which can be completed in less than two minutes.
Approximately 10 seconds after scanning is complete, iTero builds a 3-D model of the impression area with the opposing dentition articulated. The digital model can be rotated in any position to analyze the preparation and verify margins (Fig. 8). A color map of the preparation allows the clinician to verify the amount of occlusal reduction. If modifications to the preparation are necessary, just that arch will require a re-scan. When the model is approved, the clinician clicks the “mail” icon with the mouse and the virtual impression is uploaded to Cadent to begin milling the physical models. Dental labs can obtain the software that enables them to make any necessary adjustments to the virtual margin line and if necessary, to discuss the case with the clinician. On average, a pre-trimmed model is delivered to the laboratory for fabrication of the final restoration in less than 3 days (Fig. 9).
This completed case was received within 10 days of scanning and the final e.Max crowns were cemented with minimal adjustment time (Figs. 10 and 11).
Conclusion
Digital dentistry has expanded greatly over the last several years. In this author’s opinion, there is little doubt that digital impressions will replace traditional methods in the very near future. No more packaging impressions, opposing models, and bite registrations that can be lost or destroyed in transit. Advances in technology are eliminating the labor-intensive and time-consuming process of pouring models, ditching dies, and manually fabricating substructures. The number of dental laboratories acquiring computerized systems that aid in the fabrication of restorations increases daily.
Predictable, accurate impressions have always been one of the more difficult procedures to perform consistently. A host of variables present daily challenges, making conventional impression taking an inexact science. Approximately 36 percent of dentists retake impressions three or more times per month. On average, 36 percent of dentists must reappoint patients for impression taking at least once per month. At least 15 percent of cases require adjustment time of 5 minutes or more at seating. iTero’s digital technology ensures a more accurate impression from the start, which results in a better fitting restoration.
Incorporating new technology into any practice not only has to make a better end product but it has to make economic sense as well. With a more predictable and superior fitting final restoration, clinicians will see a dramatic drop in seat times and virtual elimination of re-makes. In this author’s practice, over 1,500 restorations have been fabricated in the past three years with only four re-makes. Seating time has been cut in half. This decreased chair time, when factored over the course of a year, is quite valuable to the bottom line.
The use of CAD/CAM restorations has revolutionized the practitioner’s ability to deliver predictable, strong, and aesthetic restorations with minimal effort. This technology surrounds us and has advanced to a level which cannot be ignored. Cadent’s iTero digital impression system has vastly improved the ability to deliver precise restorations with proven technology. It is making its mark; now it’s time to make yours.