Introduction

I would bet that most readers do not realize the tremendous and widespread impact that digital imaging has already made on our profession – especially upon the specialties. Digital imaging is used by endodontists, periodontists, orthodontists, oral and maxillofacial surgeons, oral and maxillofacial radiologists (of course), cosmetic dentists and prosthodontists. Digital x-ray systems are used for subtraction radiology in periodontics, CT and MRI by surgeons and radiologists and for root canal therapy by our endodontic colleagues. Digital imaging systems using video cameras are used by prosthodontists (and general clinicians) for performing CAD CAM restorations. And now, because of imaging programs and engineers, plastic "aligners" are used instead of brackets for minor orthodontic tooth movement (Invisalign™).

Digital Imaging and Endodontic Treatment

It’s no surprise that endodontists were the "early adopters" of intraoral digital x-ray systems. Rapid image acquisition, low dose intra-treatment x-ray assessment and speed were the factors influencing these specialists to "go digital". Even in the general dentist’s office these attributes are hard to resist. Who wouldn’t like to lower the patient’s x-ray dose? Who wouldn’t like a faster image for establishing the "working length"? Who couldn’t use a quicker image of the "hot tooth" of a new "emergency patient"? What dynamite ways of establishing better patient rapport and treating patients more efficiently! What a great practice builder!

Figure 1.
CCD image of successful endodontic treatment taken with ProVision DEXIS sensor

Digital Imaging and Periodontal Therapy

Another group of early adopters were the periodontists. The ability to use the software of digital x-ray imaging systems to subtract the original treatment x-ray from the follow-up image and quantitate and colorize the changes to better assess the success of the procedure was very attractive to this group of specialists. Several software programs on the market have this "digital subtraction" capability. Although the application is limited, it gives us one more impressive tool to help us manage our therapy more precisely.

In addition to the subtraction tool, digital x-ray systems are being used by periodontists to perform pre- and post-surgical implant site assessment and integration. More and more of these specialists see the advantages of digital imaging for implant procedures. Pre-surgical assessment of multiple implant sites using CT (computed tomography) is another use of digital imaging. Although more expensive than intraoral imaging on a case by case basis, CT images of implant sites have the advantage of seeing the precise width of the proposed site and can be reformatted into 3D images when necessary. Even the periodontist is "going digital"!

Digital imaging and Orthodontics

Orthodontists have been "digitizing" plain cephalometric images for years to perform various orthodontic analyses to predict tooth movement and assist treatment planning. Orthodontists have also recently begun to adopt a new treatment modality called "InvisalignTM". This "non-braces" approach was made possible by engineers who could image the patient’s models, construct a treatment approach by mapping desired tooth movement, and custom manufacture a set of plastic "aligners" to be changed each 2 weeks to move the teeth in small increments until the teeth were straight. Although the technique requires excellent patient compliance and can only be used for minor, adult tooth movement, it does not require the patient to wear "braces". Needless to say it is becoming very popular, and it is made possible by digital imaging!

Digital imaging in Oral and Maxillofacial Surgery

Oral surgeons have been using CT and MR for imaging facial trauma, for presurgical planning for head and neck lesions and temporomandibular joint assessment for many years (figure 2). Knowingly or not, these specialists too, have been using digital imaging. 3D reconstruction of digital data of bullet wounds, motor vehicle accident trauma and tumor assessment are all made possible through the use of digital images and computers. OMF surgeons are even "performing" virtual surgery prior to the actual procedure using experimental robotic/surgery systems. It is possible to "fly" through the patient anatomically using digital imaging.

Figure 2 - MR image of TMJ meniscus

Digital Imaging and Cosmetic Dentistry

One of the first clinical or non-x-ray uses of digital imaging software was to allow the dentist to perform cosmetic imaging of the patient to show what the "end-product" could be like for the patient. These software packages used clinical video or still images and image processing tools to show the patient what they would look like with a diastema closed, an edentulous space restored, teeth bleached, etc. All of these systems employed digital imaging devices and image software to help the dentist educate their patient and to help the patient, in turn, make an informed treatment decision. The process is so much faster than performing a "diagnostic wax-up"!

Digital Imaging Applications for Prosthodontics

The data supplied to the milling machines used by the various CAD CAM systems gets there by digital imaging. A video image is acquired of the tooth preparation and this image data is sent to the lathe to precisely cut the appropriate prosthodontic restoration. Yes, it’s true, even the prosthodontist has adopted digital imaging! And these machines are truly capable of reproducing the precise tapers of full crown preparations, leaving only the pre-programmed space for optimal cement thickness.

In addition, the patient’s clinical digital images of tooth shape, size, translucency and enamel characterization needs can also be sent to the laboratory technician with the prescription. All of this is possible through digital imaging!

Summary

There is almost no aspect of dentistry that digital imaging technology has not touched in some way. I have outlined only a few of the current applications. Digital imaging will allow us to detect disease changes better, make more informed and confident treatment decisions, and allow all of us, specialist or general practitioner to communicate with our patients and each other more expertly.