Cracking the Smile Code

The pursuit of the perfect smile is not a trivial one. It is supremely important to countless patients, and has become a revenue booster for numerous dental practices. But even though tooth-colored restorations are now a reality, causing many patients to ditch the silver fillings and go faux au naturel, the key to cracking the code to the perfect smile is much more involved.

Good esthetic treatments must not only take cosmetic appearance into account, but also function, which includes correct occlusion and reasonably tight interproximal contacts. Therefore, accurate tooth anatomy and proper alignment must be ensured in restorations. And to arrive at results that truly look natural, a range of intricacies must be taken into account. These include surface textures, shadings, translucencies, and characterizations, which can range from microfractures to hypercalcifications.

Fortunately for clinicians, cosmetic dentistry has evolved past the point of the purely subjective judgment call. Thanks to a number of digital technologies beyond radiography, clinicians can either craft high-quality chairside restorations or work more efficiently with their lab technicians through enhanced digital-based communication. The end result is the ability to give their patients the best smiles they’ve ever had.


SHADE-MATCHING SYSTEMS

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The problem of mismatched shades reportedly accounts for as much as half of all prosthetic remakes.1 it’s easy to see the value in the enhanced precision offered by shade-matching systems. The traditional way of matching tooth shade to restorative material shade is to hold shade guide tabs next to the patient’s teeth until a perceived match is determined. The corresponding number on the shade tab is then sent to the lab.

But this method reportedly may lead to inaccuracies due to failure to consider multiple variables. For example, tab colors can change with age. In addition, color choice is subjective, and is dependent on the variables such as the clinician’s eyesight and color perception, what the patient is wearing and ambient light sources.

“One of the greatest challenges I still see for clinicians in cosmetic dentistry is related to the area of color,” says Joe Ontiveros, DDS, a professor in the Department of Restorative Dentistry and Prosthodontics, and head of Esthetic Dentistry and the Oral Biomaterials Division at the Houston Center for Biomaterials and Biomimetics at the University of Texas School of Dentistry. He notes that to help remedy this, the recently formed Society for Color and Appearance in Dentistry is bringing researchers and clinicians together to collaborate on the various aspects of color in dentistry.

Today, more emphasis is placed on the tooth as a three-dimensional (3D) entity, in which value, hue and chroma are determined. Digital shade guides that take these factors into account are helping clinicians build higher quality into their restorations through color mapping. Shade-matching systems come in two forms: dot-capture, in which numerous readings are taken of small areas over the surface of the tooth; and whole-tooth capture, in which a single reading of the whole tooth is taken. These devices are also typically either spectrophotometers or colorimeters.

Among the available technologies are hand-held LED-based units that provide three light options. The goal is to counteract metamerism, a phenomenon in which a shade appears to be different under varying lighting conditions. The beauty of such technology is a restoration that offers a more precise match whether in daylight, incandescent and other lighting situations. This can lessen the possibility of perceived mismatches and resulting remakes.2

Grand Rapids, Michigan-based practitioner Betsy Bakeman, DDS, says it’s most important to get basics down first. “Then,” she adds, “the little characteri­za­tions are put in. That is where the artistry enters the picture.” Among those characterizations are shadings and translucencies, which can be created with the use of tints and opaquers. But thanks to the availability of multilayered blocks of ceramic material that can be used to mill restorations, building in these features has gotten easier.

Numerous clinicians agree that traditional shade guides remain valuable in shade determination. But many believe they are best used in conjunction with digital shade-matching technologies. According to Atlanta-based practitioner Ronald E. Goldstein, DDS, improvements in shade taking devices, lower costs and easier use are among the recent gains in esthetic dentistry. But he anticipates further improvements down the road. “In the distant future,” he predicts, “I think my idea of a combination of spectrophotometric scanners and 3D printing will be developed.”


SMILES BY DESIGN

Currently, there are numerous smile design systems available to deliver esthetic results of the highest order. These typically combine design software with other digital technologies, such as intraoral scanners and computer-aided design/computer-aided manufacturing (CAD/CAM) units or, more recently, 3D printers. In fact, 3D printers may be called on to create mock-ups for patients to test drive. But the technology that is often the most important first step in this process is the 35 mm digital camera.

“While there have been many innovations in dentistry from single-visit implants to digital impressions, the one area that has made a tremendous impact on the field of esthetic dentistry in the last decade is greater communication between the dental laboratory and the clinician through digital photography,” says Joe Ontiveros, DDS. A professor in the Department of Restorative Dentistry and Prosthodontics, and head of Esthetic Dentistry and the Oral Biomaterials Division at the Houston Center for Biomaterials and Biomimetics at the University of Texas School of Dentistry, Ontiveros notes that before the advent of the digital age, clinicians relied on hand-drawn sketches, slide film, or Polaroid pictures to communicate. “Nowadays,” he says, “digital photography is taught in dental school and has become the mainstream mode of communication within esthetic dentistry. Clinicians can seamlessly communicate using cloud storage and send several digital images as part of the routine practice.”

Betsy Bakeman, DDS, a cosmetic dentist who practices in Grand Rapids, Michigan, agrees, but says that taking good diagnostic photos is one challenge with which people struggle. Nevertheless, she stresses the importance of such images, which can help both clinicians and their patients see beyond the obvious. “For instance,” she says, “the patient may say, ‘I don’t like the space between my front teeth,’ but there may be other things that detract from the appearance of the smile that the patient may not be aware of until the obvious detractor is corrected. This might include uneven gum heights, tooth color, old fillings or misalignments. The bottom line is to achieve symmetry and harmony within the framework of the smile from all angles.”

Once images have been captured, they can be uploaded to a smile design program, through which restorations can be simulated on screen. The process is similar to how photographs are manipulated via other kinds of computer programs. With the help of a variety of digital tools, vertical and horizontal orientation lines are established on the patient’s digital photograph, to aid perspective. This helps clinicians verify how teeth fit into the face as a whole, in a sense, crossing over into orofacial territory.


POINT OF SALE | SMILE SUCCESS

  • Smile design systems allow easy manipulation of uploaded images to create a desired look.
  • Odds for success and patient treatment acceptance are improved with digital smile design systems in that patients can be active partners in their own smile designs.
  • Digital impressioning not only improves the patient’s experience but is also more likely to deliver error-free impressions.
  • CAD/CAM systems offer integration of digital technologies such as smile design software, intraoral scanners and milling capabilities.
  • Shade-matching spectrophotometers and colorimeters allow clinicians to clearly map out shadings that are scattered over the surface of a tooth.

Bakeman notes that utilizing these systems can help clinicians determine whether the teeth are in the right place, both vertically and horizontally, and whether the gum tissue is in symmetry and harmony. “For example,” Bakeman explains, “there are metrics/norms for the degree of tooth structure that should show when the lip is at rest, where the lip and biting edges of the teeth should be in relationship to the base of the nose and how much the lip should move. With metrics, we can determine where the patient is in relation to what we consider normal or average, and make decisions to move the treatment in this direction, which is often what we find attractive.”

An examiner and mentor for the American Academy of Cosmetic Dentistry, Bakeman says that once clinicians learn these basics, they can go on to focus on microesthetics — such as the shapes of the teeth, the line angles on the teeth, texture, fine details, and luster. A range of tools, including mirroring tools to ensure symmetry, may aid this process. Shade may also be a selection option, using a program’s digital shade guides, which correspond to analog shade guides, or by digitally cloning native tooth color and then tweaking via features such as brightness and translucency.

Perhaps one of the greatest benefits of smile design systems is that all of this digital information can be shared with patients in a matter of minutes in the form of side-by-side, before-and-after shots prior to treatment even beginning. As a result, this technology not only serves as an effective patient education tool, but also involves patients in their own esthetic designs for more predictable outcomes.

“The advent of digital smile design has influenced esthetic dentistry worldwide,” says Ronald E. Goldstein, DDS, an Atlanta-based cosmetic dentist and a prolific author and educator on the topic of cosmetic dentistry, who is a co-founder of the American Academy of Esthetic Dentistry. In fact, he adds that the process has become so popular he has included a special chapter on it in his latest textbook.3

DIGITAL IMPRESSIONS

Once patients and their dentists have settled on an esthetic treatment plan, the next step is fabrication. And beautiful dental prostheses, of course, start with accurate impressions. Though many clinicians still rely on traditional impressions, many others report the myriad benefits offered by digital impressioning via intraoral scanner.

Digital methods don’t require the use of trays and impression material, which most patients find uncomfortable, and don’t have issues involving tearing, voids or distortion. Thanks to precise, three-dimensional, color imagery, excellence is ensured. But if a spot is missed, it’s easy to simply rescan that area. Workflow is also streamlined, communication between clinician and lab is improved, and waste is eliminated. The result is a boost to timesavings, accuracy, patient satisfaction — and possibly five stars on Yelp.

“The continuous development of scanning abutment teeth instead of taking conventional impressions has made it easier for both dentists and assistants — and most importantly, the patient,” says Goldstein. “Ease of design plus accuracy, especially with the newest technology, will no doubt increase the popularity of the technique.”

Quality impressions are the blueprints for the design and manufacture of dental prostheses. And when those blueprints are digital, they can dovetail with other digital technologies to facilitate restorative protocols.

UNDERLYING TECHNOLOGY

According to a recent report, among the principle drivers of growth in demand for cosmetic dental treatments are technologies such as CAD/CAM.4 These kinds of systems, which combine scanning with designing and milling capabilities, and in some cases, chairside sintering and glazing technologies, are increasingly being used in-office to streamline and improve indirect restorative processes.

“There’s no question in my mind that the advent of CAD/CAM ceramic indirect restorations has taken the practice of dentistry by storm,” says Goldstein. He believes that CAD/CAM has been the single most important advancement in esthetic dentistry since the development of composite resins. “Both general dentists and prosthodontists have embraced the technology at an astonishing pace,” he notes.

But while Ed McLaren, DDS, director of the University of California Los Angeles Center for Esthetic Dentistry, observes that CAD/CAM is clearly gaining traction in dental offices, he says there are issues that need to be resolved. “For chairside dentistry, the fidelity, or fit, of restorations can be more challenging than if the practitioner were to use an experienced lab,” says McLaren. “While it does work, it isn’t as high a quality as what you can get from a high-quality lab. Chairside units are improving, but there is room for growth.”

McLaren foresees continued improvements in a number of esthetic dentistry’s facets, and believes that the digital model technique is a promising development that will make it easier to do conservative dentistry. For instance, McLaren says that the biggest challenge with hand layering porcelain is the model work. The creation of feldspathic porcelain veneers, long regarded as a highly esthetic choice, usually takes up two-thirds of the model process. In addition, he says that labs are having a hard time finding people with that kind of skill set.


LEXICON

Chroma: Color saturation.
Colorimeter: A device that measures the absorbance of color by an object.
Feldspathic porcelain: A glass ceramic restorative material.
Hue: A color’s position on the color spectrum.
Hypercalcifications: Defects in tooth enamel that appear as white spots.
Microfractures: Hairline cracks in teeth.
Spectrophotometer: A device that measures transmittance or reflection of the wavelength of light.
Value: Brightness.


“But if these processes for really good, accurate model work can be digitized, all the lab has to do is scan the inside of an impression, and then coming out of their CAD/CAM machine or printer is a completely finished model that’s ready to have porcelain applied,” says McLaren. “As a result, I think you would see a resurgence in popularity for these kinds of restorations.”

Says Bakeman, “CAD/CAM is really up and coming, but the skill and expertise of the person milling and finalizing the restoration is of utmost importance. It goes back to the scan, as well.” For that reason, she stresses that it’s important to take the time required to ensure accuracy.

In addition to the gains made by digital dentistry, Bakeman also credits the Internet with making a huge impact on dentistry. “Patients considering esthetic enhancements are doing their homework,” she says. “The Internet has really impacted patients’ ability to research options. Access to information on the web is a major shift.”

This means that clinicians who employ cutting-edge tools in the interest of delivering the best results for their tech-savvy patients are likely to maintain and build a solid patient base. After all, in today’s world of blazing white perfection, looks are important. But for the dental practitioner who lacks the technological bag of tricks to crack the 21st-century smile code, looks can also kill. Make sure your clients are equipped with the right combination to solve whatever esthetic puzzle lands in their chairs.

 

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REFERENCES

  1. Sagara J. Shade matching for today’s dentistry. Available at: dentaleconomics.com/articles/print/volume-92/issue-1/features/shade-matching-for-todays-dentistry.html. Accessed June 30, 2017.
  2. Berland L, Yared S. Shade-matching challenge: A single central incisor. Available at: dentistrytoday.com/articles/10239. Accessed June 30, 2017.
  3. Goldstein R. Esthetics in Dentistry, Volume 2: Esthetic Problems of Individual Teeth, Missing Teeth, Malocclusion, Special Populations. 2nd ed. Hamilton, Ontario, Canada: BC Decker Inc; 2014.
  4. Grand View Research. Market Research Report. Available at: grandviewresearch.com/ industry-analysis/cosmetic-dentistry-market. Accessed June 30, 2017.

 

Featured image by ANTONIOGUILLEM/ISTOCK/GETTY IMAGES PLUS

From MENTOR. August 2017;8(8): 12-14,16-17.

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