Oral Health Group
Feature

ENDODONTICS: Digital Documentation and the Dental Operating Microscope

December 1, 2001
by Glenn A. van As, DMD, BSc.


The surgical operating microscope has become an integral part of the medical field since 1957. It has become a necessity within the disciplines of neurology, otolaryngology, and the microsurgical reattachment of severed appendages and vessels to name but a few.1-7 The dental profession has been slower to accept the microscope as part of its regular armamentarium. Only those within the discipline of endodontics are regularly using the microscope and its ability to improve visual acuity through enhanced magnification and superior illumination.8-12

The use of any form of magnification in general practice was initially considered a weakness, and limited to aging dental practitioners looking for something to aid their increasing myopia. This concept has changed drastically in the last 20 years to the point where first-year dental students are now routinely beginning their careers using low power loupes.8,11

Presently in British Columbia, the routine usage of surgical telescopes (loupes) has risen from 20% in 1986 to 75% of practitioners in 2000. The routine acceptance of 2.5X magnification loupes in today’s dental practice has spurned many practitioners to seek out higher levels of magnification often with an auxiliary headlamp, in an attempt to visualize the operating field better. As the desire to utilize higher magnifications has surfaced within the profession, an increasing number of general practitioners are seeking out the possibility of utilizing the Dental Operating Microscope (D.O.M.) routinely for all procedures. This author has been using the D.O.M. for almost 100% of all clinical procedures including diagnosis, restorative dentistry, prosthodontics, oral surgery and endodontics for nearly four years.

One advantage of using the D.O.M. in daily practice is the ability to work in a more favorable ergonomic posture where the upper and lower sections of the spinal column are placed in a neutral, and balanced position. As practitioners age it becomes more common for the operator to lean closer to the operating field, or to raise the patient higher horizontally in an effort to see. Surgical telescopes, if adjusted to a proper focal distance, will encourage the operator to sit upright in a more ergonomically friendly position. Unfortunately, the operator still can easily shift to their right or left to aid viewing of the operating field, and this movement again will shift the operator away from this ideal neutral position. With the microscope, since the operator must peer through the binoculars to see, the view of the operating field is dictated more by the movement of the patient and proper dental mirror placement than what is typical with loupes (Figs. 1 & 2).

In a recently completed study done in British Columbia, it was discovered that 60% of dentists suffer from back pain and the average clinician misses one to two days of work annually due to musculoskeletal problems related to poor posture at work.12 Since musculoskeletal injuries and disabilities are so common amongst dentists, it behooves us to seriously consider any improvements in armamentarium that may be able to decrease the risk of these injuries (Figs. 1 & 2).

Another advantage of using the D.O.M. is the improved visual acuity provided by the unsurpassed magnification and illumination. The opportunity to view the oral cavity at 10-16X magnification, and to treat the areas at this same magnification, allows for a level of precision in treatment never before encountered within the profession. Unsurpassed diagnosis of incipient caries, cracks and marginal breakdown can aid in earlier treatment of pathology. Earlier diagnosis leads to conservative treatment utilizing smaller instruments with greater precision and predictability13 (Figs. 3-8). The greater illumination and magnification of the D.O.M. allows for better visualization of the texture of surfaces allowing for the complete removal of carious dentin which has a leathery appearance at higher magnification. In addition, the increased magnification allows for the confidence that interproximal margins on full coverage restorations, even in the posterior sextants, are not placed on restorative materials (amalgam or composite), and are free of decay, cracks or calculus. Impression voids and bubbles are quickly identified by the practitioner before the impressions are sent to the laboratory, and the confidence that crowns are seated by visual examination instead of tactile feedback (explorer) are all clinical areas where the value of the D.O.M. for dentistry has been documented in other articles14-22 (Figs. 9-14).

As the general practitioner using the D.O.M. integrates the scope into his practice there becomes a desire to document the procedures being completed with such precision from beginning to end (Figs. 15-18). Until recently, 35mm photography was the standard, but it was extremely difficult to use with the microscope. Illumination of the operating field with a strobe light flash was necessary, yet it was inconsistent and often produced vignetting or incomplete illumination of the operating field. The inability to immediately see the photographs taken until they were returned from the lab, led to the clinicians shooting far more photographs than necessary, in order to perhaps get a few successful shots. As the magnification increased, the level of difficulty in getting a sharply focused, well illuminated and color correct photograph became increasingly difficult.

With the recent rise in the use of digital cameras, came a unique opportunity to attach a lightweight digital camera (Nikon Coolpix 950, 990 or 995) to the microscope through a specially designed adapter (Carr adapter) (Figs. 21 & 22). This addition to the D.O.M. provides the opportunity to shoot sharp, clear and immediately viewable digital images. If the setup is combined with the connection of a simple cable from the video output of the digital camera to either a large 20 inch TV, or a flat screen LCD computer monitor with a video input, the opportunity to photograph, document and view clinical cases immediately becomes possible (Fig. 20). The digital images captured by CCD sensors in the camera require less light than 35mm film and therefore no flash is needed to illuminate the field even at higher magnifications. This results in less shadows and vignetting and an ability to reliably assess the quality of the images immediately, and if necessary to delete the image and retake the photograph.

Traditional photography with 35mm cameras can increase the magnification of the operating field to roughly 4-6X magnification depending on the proximity of the camera to the object.

Dental operating microscopes have multiple steps of magnification that can range from 2.5X to 40X magnification depending on the microscope and its manufacturer. In our office the Global Surgical corp. microscope has 6 steps of magnification (2.64X, 4X, 6.4X, 10X, 16X, and 24X power). The lower powers of the microscope (2.5-4X magnification) allow for the viewing of multiple teeth in the field during complete examinations, diagnosis, periodontal surgery, and gross reduction of tooth structure during full coverage prosthodontic preparations. The medium powers (6.4X-16X) are the ideal working range for most clinicians using operating microscopes.

The highest powers of magnification allow for spot checks during treatment and for digital photography at much higher power than what is obtainable with traditional means.

The immediate feedback received when shooting digital photographs allows for both simple and thorough documentation to be completed at high magnification. If the camera is put into the play mode, the patient can be given a visual tour at high magnification of the just completed procedure. Studies have shown that patients remember far more of what they see than what they hear, and the ability to demonstrate in magnified photographs, allows for better communication between the doctor and patient.

Digital photographs are much clearer than analog photographs captured by traditional intraoral video cameras because the limitation of these intraoral cameras stems from the native resolution of the video camera being a maximum of 512 lines of resolution. A true digital image from any of the 2.1 or 3.3 megapixel digital cameras will almost always be better in clarity and resolution than a captured image from analog video.

The video output from the digital camera gives the patient and staff the opportunity to see in real time the procedure as it is being done. The quality of the video from the digital camera is not as clear as a true, dedicated one or three chip video camera, which can be attached to the opposite side of the microscope with the addition of a dual beamsplitter. But the video output from the digital camera can be used for patient education and for staff to give them a first hand view of the procedure as seen through your eyes. In informal studies done in our office, roughly 80% of the patients when given the choice of watching TV, the procedure we are completing on them or nothing at all will choose at some time during the appointment to watch the procedure. I encourage them to do so as they tend to hold more still, and even the anxious patients mention that the ability to “see” what I was doing helped put them back into control of their anxiety by eliminating the unknown (Fig. 19). If you doubt this, check out how many of your patients are trying to see from the reflection in your prescription or safety glasses what you are trying to do in their mouth.

As a marketing tool the digital camera hooked up to the microscope can be very useful. Today’s patients are very educated and many have remarked after watching me complete a restoration, that they felt that another restoration in the immediate vicinity of the one I was working on looked suspicious. The primary focus of using the microscope was to allow me to complete my dentistry with more precision than I could previously with low-powered loupes, but the patients viewing procedures done under the microscope were more likely to suggest further work being completed in the same area that I was working on. In addition, in those instances were interproximal decay had affected an adjacent tooth or where additional teeth required treatment in the area that I was working, it was easier to show the patient and get their approval for treating all teeth at the same appointment, when it was possible to show them the additional areas requiring treatment.

I often complete my new patient exams with the patient watching me tour their mouth at high power. As I mention to my assistant, the patient is taking in the virtual visual tour of their oral cavity. I am reading off to the assistant existing treatment and areas requiring treatment, the patient is able to see what I am seeing and to listen as I recite my findings. I can capture still digital images of teeth requiring treatment and show them afterwards to the patient.

Video output from a dedicated one or three chip camera, or from the digital camera output, can be used to not only educate patients on why a procedure is needed in a similar fashion to intra-oral cameras (co-diagnosis), but unlike intraoral cameras, the microscope can allow for the patient to observe the actual procedure being completed at the same magnification the diagnosis was done at (co-treatment). Many patients appreciate the “high tech” nature of what the microscope offers, and there is the inherent understanding that this is not available in all offices. Practice differentiation in today’s competitive marketplace is a necessity in many areas and the microscope allows for the dentist to market his uniqueness.23

In photographing cases with the microscope, there is a considerable time saved over traditional photography. The dentist simply continues to view the operating field while the assistant either presses the shutter or triggers the shutter via a remote. The latter will substantially reduce the camera shake during the process. Disciplines such as periodontics where procedural photographs are continually taken, can realize a significant reduction in time when using this setup.

The uses of digital photography within the dental practice are numerous. In addition to educating patients, the photographs can be embedded into the office computer software program, and allow for a visual catalogue of procedures on a patient for the dentist to review. These images can be integrated into the paperless office as an image library for each patient’s file.

For specialists, such as endodontists, the photographs are easily attached to emails for correspondence with referring dentists or embedded into templates and printed out as a hard copy to send in combination with digital radiographs and text in the final post treatment letter back to the referring dentist. For the general dentist, the opportunity to communicate with the specialist in visual terms by sending an email with the photographs attached makes the case much clearer for all involved. When taking custom shades with the higher magnification provided by the microscope, it allows the dental laboratory a much more detailed look at the shading and topography of neighbouring teeth. The laboratory is able to make adjustments easier with a visual guide to the case.

In communicating with staff, the ability for them to see a first hand view of what you are looking at is of tremendous benefit. Firstly, it is much more interesting for all assistants to see what you have always seen. Their excitement at being part of the whole diagnostic and treatment process allows for them to anticipate much better changes in routine without explanation. In addition, the assistant is able to also view cracks, decay or other pathology not spotted by the dentist. The assistant is able to suction in even difficult procedures (searching for root tips for example) without standing and without interfering with the dentist’s view since she is able to see exactly where she is with the suction tip from the video output from the scope. Working with the microscope requires excellent four or six-handed dentistry as the operator likes to try and keep his eyes focused on the scope. The ability for the assistant to see what the dentist requires next and what the various instruments are used for is ideal during the training of new staff. Many practicum auxiliary personnel have remarked at how much easier it was for them to understand what the various uses of instruments were, once they saw them in action (Figs. 23 & 24).

Digital photographs can allow for the dentist to post his photographs on forums or newsgroups such as www.rxroots.com or www.rxdigimage.com and get feedback from other dentists on a certain case. The ability to shoot the photographs during the day and post the case immediately can yield valuable quick advice from colleagues world wide, which can be useful to providing an immediate solution to the dentist’s queries.

In addition, the opportunity to use the digital photographs for lecture purposes, or to integrate the photos into Microsoft’s Powerpoint program for before and after pictures, to have playing in the reception area or to print out for hard copy in an atlas to show what is possible to achieve in the office is very professional. Even regular radiographs can be placed on a lighted viewbox under the microscope, turning the fiberoptic light source off on the scope and the overhead light in the operatory off, a radiograph can be digitized very easily and then integrated into the presentation (Figs. 25a & b).

Traditionally difficult to photograph areas such as internal aspects of root canals, distals of 2nd molars, and root apices during endodontic surgery are possible with the microscope, very small mirrors and digital cameras (Figs. 27 & 29).

The future will allow for not only the digital photography of cases, but very soon the digital videography of cases will be routine. As the size of mini-digital video camcorders drops in size and weight, and as manufacturers start to implement three chip CCDs into the handicams in a reduced size, there will soon come a time where procedures will be digital video taped routinely. Already, some clinicians are producing digital video through today’s mini DV cams (Sony PC 110) or running the analog video from their one or three chip cameras to Digital Video Recorders to capture the video footage digitally.

Traditional video documentation with analog sources to VCR can tape record procedures. These then can be transferred over to digital formats such as AVI, Mpeg 1 and 2 via external capture devices such as Dazzle or Pinnacle systems. These external capture devices come with introductory software which will allow for editing, splicing, and adding titles to the video footage. In addition some stills that are of medium quality resolution are possible to capture from the video footage. Analog video will lose resolution as it is manipulated, so if the final destination for the video is on a computer (digital format) the preferred format for the captured native video would be in digital format (digital tape or via direct connection by firewire [IE1394] from the video camera to the computer).

The process of video brings a whole new element to the educational process and when the video is magnified by the microscope to 10X power and higher, the viewer is given a tremendous ability to see the procedure as never seen before. Many of today’s clinical leaders are looking at digital video attached to the microscope as the future for documenting and teaching advanced dental education courses. As broadband Internet connections grow and as full screen video on the Internet becomes possible in the near future, the opportunity of viewing live full screen video captured of microscopic dental treatments will be commonplace. The clinician via the Internet teleconferencing will be able to watch live procedures completed at incredible magnification and detail from the comfort of their home computer. These incredible days of the “online lecture” are not that far away.

In closing, the digital world is here to stay, and dentistry is no different. As these new digital technologies are combined with the Dental Operating Microscope to provide documentation of our daily routines, the opportunity to communicate with colleagues, staff and patients will change forever.

Glenn van As is in private general practice in North Vancouver, B.C., where he has incorporated the use of surgical operating microscopes and multiple wavelengths of lasers into daily practice.

Oral Health welcomes this original article. Complete references available upon request.

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