Communication

Enhancing Interprofessional Communication Through Digital Photography

Anthony G. Gallegos, DDS

Copyright 2001 Journal of the California Dental Association.

Dentistry has enjoyed more technological advancements in the past 10 years than in the previous 50. A majority of that technology has become common in today’s dental practice. Intraoral cameras, digital radiography, air abrasion, CAD/CAM dental units, and various laser systems are many of the technologies that are headlined at dental conventions not only in North America but throughout the world. Dental offices are rapidly becoming digital and must communicate digitally not because dentistry demands it to but because the technology available to many other professions, businesses, and consumers (patients) demands it. One such digital technology, digital intraoral photography, can enhance communication between dentists and dental ceramists. This article will explain a simple and inexpensive approach to approaching the esthetic dilemma of restoring teeth in the esthetic zone.

Today’s dental clinician has a myriad of esthetic materials at his or her disposal. Yet, regardless of the material chosen for crown and bridge prosthetics, many dental offices fill out laboratory prescriptions with minimal instructions such as, "Make PFM #9 shade A2." The laboratory ceramist is left in a quandary as to how to fabricate an esthetic restoration with only generic instructions. The lab ceramist makes a plain-looking crown, despite the ceramic restoration chosen, that replicates the generic shade tab as closely as possible. Upon looking at the crown at the insertion appointment, the dentist and team are usually less than excited about the result. The dental office had a certain level of expectation of the prosthetic result and probably a mental vision of what the definitive prosthesis would look like.

The goal of any communication is for the sender to articulate his or her message clearly so that the receiver understands the message. It would be ideal if the message generates in the receiver the same mental picture that the sender visualized internally and then transmitted externally. Historically, in their efforts to achieve success beyond generic-looking restorations, dentists have utilized everything from crude drawings, commonly known as shade mapping, to intraoral photography for communication with ceramists. Drawings have improved results, but they can be misinterpreted depending on the artistic qualities of the person drawing the picture.

On the other hand, many clinicians have attempted to use traditional film-based modalities to communicate their ideas to ceramists. This requires specialized cameras and attachments for close-up and intraoral images. The learning curve is high, and the technology not readily usable by the entire dental team. Exposure and composition errors are not caught until the film has been processed, which is usually after the operative site has been altered. In addition, the desire to use an entire roll of film before processing can delay submission for developing. Also, traditional film, both print and transparency (slide), can yield color shifts that vary among manufacturers and depending on the type of film used (daylight, low light, chrome, portrait, etc.)¹ These color shifts and the entire developing process can give a hue to the final photo that is too red, blue, or green. Slide film also requires specific projection equipment and a darkened environment to view the photographic results.

For all of these reasons, the photographic depiction of a tooth’s value and chroma can be different from the actual clinical situation. To address these issues, the current state of the art for esthetic clinicians is a combination of photographs, drawings, prescriptions, diagnostic models and wax-ups, photo atlases, and even photo clippings from magazines that the patient may have brought to the office.²

Recent advances in digital cameras, imaging software, and printer capabilities are allowing the esthetic clinician the opportunity to address some of the toughest shade-matching challenges. Previous digital attempts have given less-than-acceptable results since camera electronics and computer printer technology were inadequate. Secondly, expensive investments were necessary to create images that approached print photographic in quality. Today, however, digital cameras are capable of images that are "megapixels" in size, and some of them are being outfitted with macro capabilities and flash units that make their extra- and intraoral use acceptable for dentistry. A variety of manufacturers offer single-lens reflex cameras with interchangeable lenses and macro-flash capabilities. Without this macro-flash capability, intraoral shots tend to wash out. The overall investment can range from just less than $1,000 to $2,400 depending on the make of camera, its accessories, software, and printer. A conventional film-based camera may be a smaller initial investment; however, there are the additional costs of film processing, print duplication, and archiving.

Digital cameras offer the advantage of viewing an image immediately, thus allowing the clinician an opportunity to check its composition and exposure. Ink jet and dye sublimation printers can give a photographic quality result, and the user can choose which images to print instead of developing an entire roll of film. The print of the digital image can then be sent with the case to the laboratory without a delay for processing film. A new digital breed of clinicians and laboratory ceramists are also communicating with each other electronically because digitized images can be sent via e-mail.

The American Dental Association has adopted recent guidelines for the development of electronic image standards.³ This digital imaging and communications in medicine, or DICOM, standard allows a common language to be used throughout the dental and medical fields.

One software developer thus far (Dicom Imaging, Inc., Blaine, Wash.) has a software suite for use in the dental industry. The suite consists of an image capture and storage system, a tooth-bleaching simulator, a cosmetic simulation module, an electronic digital X-ray viewer, and an electronic laboratory prescription module. Other companies are also developing their own versions of digital capturing and storage software, and consumer software suites can also be used for the dental office. It is not difficult to predict that the next evolution of office procedure will include an electronic patient chart that includes digitally captured images.

Case Examples

Several cases will be used to illustrate how digital photos and electronic sharing of images can facilitate communication between the clinician and ceramist.

Case 1

Laboratories often receive simplified prescriptions and stone models that are green, purple, blue, pink, yellow, etc., and constructed from impressions. If the prescription calls for any one of the available all-ceramic restorations, the vitality of the definitive restorations will be compromised because the stone model lacks the reflective and refractive optical properties of natural dentin. Communication of shape, dimension, and shade is important. One often overlooked visual aspect of teeth is incisal translucency (Figures 1, 2, and 3).

The restorations depicted exhibit a naturalness that permits the definitive restorations to show vitality and esthetic characteristics. The definitive restorations look natural and blend with the adjacent natural dentition. The other vital aspect is value -- the degree of grayness a tooth has. Lastly, minimal attention is given to surface anatomy and glossy characteristics. In the author’s numerous conversations with laboratory ceramists, it is generally agreed that these last two characteristics of value and surface anatomy/glaze are key elements. In fact, a dentist could give the wrong shade tab chroma intensity, yet give the correct value and surface anatomy/glaze and the resultant restoration will blend with the adjacent dentition quite well. The case shown in this example required a cooperative analysis by dentist and lab ceramist. Facial analysis using a Trubyte Tooth Indicator (Dentsply International) requested a central incisor with tooth dimensions of 8.75 mm wide by 11 mm long. The preoperative condition depicted a 1:1 width to height ratio. The lab ceramist uses the digital photos to plan the case and examine the effect the final dimensions would have on the overall restorative/esthetic result.

Case 2

The second case (Figures 4 through 7) depicts the typical dilemma of matching a single anterior tooth. In this case, the young female patient had a unique hypocalcified pattern on the adjacent central incisor. Some of the light elements of the camera’s macro flash ring were obstructed to aid the visualization of the subtle calcification pattern. It would be difficult for the clinician to communicate this pattern to the ceramist in any method other than photographic. Having the patient present at the laboratory for custom shading would most likely tax the creative abilities and patience of the ceramist. In addition, to go to the lab, the patient would have to coordinate her schedule with the laboratory technician’s. A laboratory more than 500 miles from the dental office was chosen to test this technology. Very simplified instructions were given to the ceramic designer: Make Empress Veneer Shade 120/110.

The resultant restoration (Figure 7) shows the artistry of a gifted technician despite a lack of information in the laboratory prescription. The photographic print sent to the laboratory aided the ceramist in understanding the unique anatomical variations within the adjacent teeth. The case was successful not only because of the excellent customization by the ceramist but also because the definitive restoration matches the adjacent teeth in their value and surface anatomy and glazing characteristics. The ceramist indicated that the shade matching could not have been this exact without the digital picture of the adjacent dentition.

Case 3

This case shows how proportionally placed restorations can aid the natural look of the final result (Figures 8 through 10). In the presented case, the patient had congenitally missing lateral incisors; and an orthodontist had attempted to lateralize the cuspids. The digital images allowed simultaneous viewing of the various aspects of the case while the clinician and the ceramist were in separate locations. Software allowed the two individuals to connect to each other’s computers and carry on a phone conversation while being miles apart. They were each able to use the mouse connected to the individual computers, and the cursor movements could be seen by the other person. The case was successful due to the use of digitized images that allowed for the proper facial and dental analysis by the clinician and ceramic designer simultaneously. The clinician and ceramist were able to co-design the case. From here the ceramist was able to render a three-dimensional, fully contoured wax-up. In this regard, the dentist had become team leader (general contractor) and the subcontractor(s) could easily communicate, contribute, and design a possible outcome for the patient to view for approval. The patient approved of the final design before the teeth were ever touched with a dental handpiece. The dentist, patient, and ceramic designer could all see and approve the desired outcome. This allowed the dentist to provide the correct amount of tooth reduction. The patient’s provisional restorations were constructed from this same mock-up, and the lab could complete the definitive restorations from the mock-up, the various digital views from different angles, and digital images of the shade tabs that reflected the patient’s true natural state.

Conclusion

With the use of one of the dental-ready digital cameras, DICOM-compliant software, and a photo-quality printer, the esthetic clinician is now capable of accurately communicating to the dental laboratory the unique esthetic challenges and desires of any case. One of the most difficult esthetic challenges, the shade matching of the single central incisor, can be consistently and reliably be performed. All that was lacking was the ability to successfully communicate the actual clinical environment from clinician to ceramic designer. This article explored case examples that illustrate the successful use of this new technology for dentistry.

A recent trend of shade communication and color mapping is the use of digital scanning technology to optically capture an image. It uses color-corrected lighting and a capture device that digitally assigns tooth shading based on widely accepted shade and stump guides. This form of communication will prove invaluable for every esthetic clinician. Unfortunately, at this time, the investment in this latest technology is too expensive for the majority of dental practices. Despite this problem, such technology represents the future of shade communication. Similar to computer technology that costs thousands this year and whose future financial investment will be smaller in the years to come, this technology will lead to the dental clinician to wanting to provide the most precise communication. It is hoped that it will become more affordable for a majority of dental practices and laboratories.

While the above may represent the future, today’s esthetic clinician can now accurately communicate shade, shape, and function to the dental laboratory to yield beautiful results that rival nature with a modest investment. The future of digital communication remains wide open for everyone from the general dentist wanting to aid the dental pathologist to the dentist wishing to consult with other dental specialists.

Acknowledgements

The author would like to acknowledge the ceramic efforts of Matt Roberts, CDT, in Case One; Kent Hallmeyer, CDT, of Frontier Dental Laboratory in Case Two; and Mike Cash, CDT, of Glidewell Laboratories in Case Three.

Author

Anthony G. Gallegos, DDS, FAGD, is TKTKTK.

References

1. Personal Communication with Kodak Film Engineers, March 1999

2. Hastings, James H., Laboratory Communication: Essential Keys to Exceptional Results, American Academy of Cosmetic Dentistry, Winter 1998

3. ADA Guidelines and Recommendations for DICOM Compliance, 1998.

To request a printed copy of this article, please contact/Anthony G. Gallegos, DDS, FAGD, 4915 Yorba Ranch, Suite C, Yorba Linda, CA 92887 or DrGallegos@aol.com.

Legends

Figure 1. The definitive restoration can have its optical properties affected in the laboratory setting with the use of various model stone colors. This can also influence the actual clinical result. Communicating the dentin color to the laboratory technician is important when dealing with all-ceramic restorations.

Figure 2. The preoperative condition shows a loss of function. There are existing ceramo-metal restorations on the maxillary left central incisor and first bicuspid.

Figure 3. The definitive restorations exhibit a naturalness to them that blends value, chroma, and surface anatomy. The incisal translucency and characterizations further add to the natural look.

Figure 4. The preoperative photo shows a Class IV fracture of the disto-incisal corner of the maxillary left central incisor.

Figure 5. Prior to prepping the patient, the clinician should take a digital photograph with the shade guide adjacent to the teeth in question. This is done prior to prepping to avoid the teeth desiccating and a color shift occurring.

Figure 6. Some of the flash elements of the ring flash were obscured to aid with the visualization of the hypocalcification pattern . The tooth has been prepped for a partial-coverage all-ceramic restoration. The margins have been placed at the gingival crest.

Figure 7. The definitive restoration depicts vitality and blends with the adjacent dentition. The ceramist was able to create a restoration that matched the adjacent dentition primarily because it was similar in value and surface gloss.

Figure 8. The preoperative condition shows missing lateral incisors and disproportioned space to accomplish an esthetic result.

Figure 9. The maxillary occlusal view.

Figure 10. The completed case. Two all-ceramic three-unit bridges were fabricated. Treatment required ovate pontic preparation in the lateral position and provisional stabilization. Abutment teeth were prepared to allow for dimensionally proportional teeth.