Creating a More Youthful Smile

The patient who is presented in this clinical case report article came into our office to share her concerns about the appearance of her teeth and to seek appropriate care. She was unhappy with the color of her dentition, the excessive amount of gingival tissue exposed when she smiled, and the significant wear and crowding present (Figure 1). A more youthful looking smile was her desired objective. Smiles can show physical and aesthetic signs of aging, and as our patients get older and keep more of their natural teeth, age-related changes of the dentition are one the main challenges of modern aesthetic dentistry.1

CASE REPORT
Diagnosis and Treatment Planning

Figures 2 and 3 show the multiple aesthetic issues that would need to be addressed. The excessive wear accentuated the excessive gingival exposure and gummy smile. Occlusal and cervical wear due to attrition, abfraction, and biocorrosion has been a problem for years.2 Due to the largely aprismatic/irregular enamel crystal form in the cervical region of her teeth along with the presence of a lower salivary pH with stress-induced tooth flexure, noncarious cervical abfraction lesions had developed.3,4 Therefore, she had to accept full-coverage restorations (PFMs) on many of her posterior teeth throughout the years. The uneven incisal edges, absence of rounded incisal embrasures, and straight-line incisal edge contour contributed to the aged appearance of this smile. The lack of adequate oral hygiene and gingivitis that was now present may have been generated by the disconnect due to the aesthetic deficits. It is always interesting to see how the hygiene and gingival tissue respond after the aesthetic deficits have been resolved. Another complicating factor was the presence of an anterior tongue thrust due to her swallowing pattern, which prevented anterior occlusal contacts.

Figure 1. Pre-op frontal view.
Figure 2. Excessive gum display. (a) Frontal view. (b) Right lateral view. (c) Left lateral view.

To address the multiple aesthetic concerns, our treatment plan called for 12 maxillary restorations (PFMs on teeth Nos. 2, 3, 14, and 15; all-ceramic veneers on teeth Nos. 7 to 9; and all-ceramic crowns on teeth Nos. 5, 6, 10, 11, and 12) and 12 mandibular restorations (PFMs on teeth Nos. 18, 19, 20 and 29, 30 and 31: all-ceramic veneers on teeth Nos. 22, 23, 26, and 27; and all-ceramic crowns on teeth Nos. 24 and 25).

Clinical Protocol
To prepare the mandibular teeth, we first corrected the antero-posterior arch form prior to placing depth cuts. A permanent marker was used to outline the excessive tooth structure that needed to be removed (Figure 4) to achieve a dentition that would be in same arch form. A depth cut technique was used (with a goal of 0.8 mm facial reduction) by using a 0.5-mm depth cut diamond No. 900-7136 (Henry Schein). The depth of the initial cut was marked with a permanent marker, as this is the most accurate method to ensure a specific reduction, and the round-ended diamond No. 112-5161 (Henry Schein) was used to remove the enamel. A 0.3-mm depth cut diamond No. 900-7135 (Henry Schein) was used to achieve a total reduction of 0.8 mm with the round-ended diamond utilized to reduce the last 0.3 mm of tooth structure. Since our target incisal reduction was 1.5 mm, and the round-ended diamond has a diameter of 0.75 mm at the tip, we sink this diamond twice its tip diameter to ensure a 1.5-mm reduction. To finalize the preparations, the external line angles were rounded/smoothed, clearance of the interproximal contacts was achieved, and the preps were then polished using a diamond (No. 8878K-31 [Brasseler USA]). By preparing the teeth with cleared contacts, we gained several advantages: our technician would have control in placing and correcting misaligned midlines, alterations in color could be made in this area to mimic natural teeth, the lingual margin was placed in a free cleansing area, and retention form was increased.

Figure 3. (a) Frontal view showing excessive wear, exposed margins, with cervical abfraction lesions. (b) Right lateral view showing excessive wear. (c) Left lateral view showing excessive wear.

After the mandibular teeth were prepped, a centric relation registration bite was taken using red PATTERN RESIN (GC America). This is an extremely hard material that is an excellent choice for taking and verifying accurate bite registrations. A model of the master wax-up was made, and a themoplastic matrix was then prepared over it to fabricate the temporaries. An additional 3-piece wax bite (DeLar) was taken. A one-piece Luxatemp (DMG America) temporary was fabricated, and Figure 5 shows the temporary at the time of cementation of the definitive restorations. The patient had been using a 0.12% chlorhexidine gluconate (Peridex [3M]) oral rinse (as directed) during temporization due to her history of poor oral hygiene; thus marginal staining was present. (Brushing with the rinse can reduce the amount of staining.) The completed mandibular restorations were mounted on the Sam 3 Articulator (Great Lakes Orthodontics) in centric relation position. A few days after insertion, the mandibular restorations are shown (Figure 6), and within a week, the gingiva had healed.

Figure 4. Occlusal view showing tooth structure to be removed first in order to form a smoother arch. Figure 5. Frontal view showing mandibular temporaries in place on day of cementation of definitive restorations.
Figure 6. Frontal view showing mandibular restorations recently bonded. Figure 7. Occlusal view showing location of malpositioned tooth structure. To make a smooth arch, the tooth structure identified with green marker must be removed.
Figure 8. Frontal view showing the preps being polished with a OneGloss 060 (Shofu Dental) polishing point. Figure 9. Right lateral view showing red PATTERN RESIN (CG America) in place.
Figure 10. Frontal view of Rapid Simplified Veneer Provisionals (RSVP [Cosmedent]) material used in temporary fabrication.

In evaluation of the maxillary arch, tooth No. 7 was facial to ideal arch form due to a linguoversion of the root (Figure 7). The occlusal view with permanent ink markings seen in Figure 7 indicates how much tooth structure was out of position and identified how much adjustment would be necessary before beginning the depth cuts for the remaining anterior teeth. After the reduction of No. 7, all anterior teeth were in the desired arch form.

We began the depth cuts for the final preparation of the maxillary teeth in a similar manner as the mandibular preps. Our desired total facial plane of reduction was 0.8 mm. The depth of the 0.5-mm cut was marked with a permanent marker, so that once the enamel was reduced, exactly 0.5 mm reduction would be ensured. This was done again for the 0.3-mm depth cut for a total of 0.8 mm reduction. The interproximal reduction was extended to the lingual aspect of each tooth for the reasons mentioned previously. A desired incisal reduction of 1.5 to 2.0 mm was obtained by sinking the tip of the round-ended diamond twice its diameter. Maxillary incisal edges were parallel not only to the mandibular incisal edges, but to the interpupillary line as well as the floor. All external line angles were polished using a suitable polishing point (OneGloss 060 [Shofu Dental]) to make the preps as smooth as possible (Figure 8). Red PATTERN RESIN was used to capture the bite, centric relation, and vertical dimension of occlusion at the same time (Figure 9). After all the maxillary teeth were prepared, the anterior teeth were impressed without retraction cord, with a 2-cord technique utilized for the posterior preps. Dr. Bob Nixon’s temporary technique was employed to fabricate the temporaries for the maxillary arch. A rubber-like material (Rapid Simplified Veneer Provisionals or RSVP [Cosmedent]) was adapted to the master wax-up to capture all aesthetic and functional lingual and incisal contours (Figure 10). The gingival one third of the facial aspect of the RSVP material was removed, and RSVP low-viscosity incisal composite resin was then placed into the matrix. Next, the low-viscosity incisal composite resin was light-cured (Rembrandt Sapphire Plasma Arc curing light [DenMat]), leaving the operator to hand place and contour the high-viscosity cervical RSVP composite resin to the facial margins with accuracy.

Figure 11. (a) Frontal view of completed case (Authentic [Ceramay] pressable all-ceramic system). (b) Right lateral view of completed case. (c) Left lateral view of completed case.
Figure 12. Completed case.

It should be noted that our restorative material choice had to be based upon creating not only the strongest restoration, but also a material that would be compatible with the mechanical, biologic, and optical properties of the underlying dental tissues.1 The Authentic (Ceramay) pressable all-ceramic system was selected due to its strength, superior optical properties, conservative prep design, and its plus-plus ingot shade, which was ideal for blocking out any discolored teeth.

CLOSING COMMENTS
In this case, we minimized the patient’s gingival exposure and obtained a balance between the restorations and soft tissues by re-establishing a more aesthetic width-to-height ratio of her anterior dentition. The aged occlusal and cervical wear of her teeth was transformed into a more youthful-looking result with rounded incisal embrasures. We also improved the color of her teeth and eliminated crowding to achieve a desired youthful-looking smile (Figures 11 and 12). The patient, as well as the dental and dental laboratory teams, were all very pleased with the outcome.

Acknowledgment
The authors would like to acknowledge that the laboratory fabrication of the restorations was done by John Wilson, Wilson Dental Arts (Raleigh, NC).


References

  1. Magne P, Belser U. Bonded Porcelain Restorations in the Anterior Dentition: A Biomimetic Approach. Chicago, IL: Quintessence Publishing; 2002.
  2. Grippo JO, Simring M, Coleman TA. Abfraction, abrasion, biocorrosion, and the enigma of non-carious cervical lesions: a 20-year perspective. J Esthet Restor Dent. 2012;24:10-23.
  3. Grippo JO. Abfractions: a new classification of hard tissue lesions of teeth. J Esthet Dent. 1991;3:14-19.
  4. Poole DF, Newman HN, Dibdin GH. Structure and porosity of human cervical enamel studied by polarizing microscopy and transmission electron microscopy. Arch Oral Biol. 1981;26:977-982.

Dr. Tyler Wynne, a 2014 graduate of the University of North Carolina School of Dentistry, practices general dentistry in Faison, NC, and is adjunct faculty at the University of North Carolina School of Dentistry. He can be reached via email at This email address is being protected from spambots. You need JavaScript enabled to view it..

Dr. William Wynne maintains a private practice in Raleigh, NC, focusing on aesthetic and restorative dentistry. He graduated from the University of North Carolina School of Dentistry (1971) and has achieved the status of Pankey Scholar. He is a Fellow of the American Society for Dental Aesthetics and a member of the American Society of Dental Practice Administration. He has published numerous articles on aesthetic dentistry, occlusion, and eating disorders. He can be reached at (919) 851-3716.

Disclosure: The authors report no disclosures.

Related Articles

Treating the Amelogenesis Imperfecta Patient

Resolving Color Variation

Conquering the Challenges of Material Selection: Key Considerations for Aesthetic Cases

 

 

A Shared Understanding: Managing Aesthetic Treatment Imperfection

INTRODUCTION
We are so hard on ourselves. Our nature as dentists is to focus on what went wrong instead of celebrating what went right. We dwell on and beat ourselves over that one patient, that one case, that one tooth that didn’t turn out as well as planned. The pain from failure is often greater than the happiness from success. Why do we do that to ourselves?
We take a single patient complaint or small compromise in a case and magnify it so that we end up convincing ourselves that we don’t measure up to others in the profession. We convince ourselves that we are the only dentist who has treatment disappointments. The truth is that we all have similar struggles. Certainly, any conscientious practitioner tries hard to do quality, patient-pleasing work. Striving to become better is what keeps the spark and passion alive in our practices. We learn from our failures. We all want to become more skilled, have more clinical success, and have happier patients. To get maximum happiness and reward from our professional lives, we must learn how to plan for and deal with an imperfect outcome.

Thorough planning and communication with the patient and lab team are key. Listening to the patient, knowing patient expectations, identifying limitations, and dwelling on the positive are all important steps for reducing tension later. There must be a shared understanding between the dental team and the patient. There are steps that can be taken to improve this shared understanding (Table).

Understanding Starts at the Patient Consult
A female patient with the desire for a better smile came to our office for an aesthetic consultation (Figure 1). Often, the road to success centers around effective photography. A few digital photos were taken by the chairside team and put up on a 35-inch monitor in the operatory and reviewed with the patient. The assigned office team member does an interview while going through each image:

  • What can we do for you?
  • What don’t you like about your smile?
  • What are the 2 most important things that you want us to correct with your smile?

These are the first steps to a shared understanding. Active listening, empathy for patient desires, and accurate documentation will help lessen disappointment later. The patient is shown the images and a list is made of what he or she does not like. Most likely, patients have never seen their teeth enlarged on a monitor; it often accentuates what they already did not like and points out flaws that they never considered.

Figure 1. At the consultation appointment, our patient stated that she wanted her smile improved.
Figures 2 and 3. A few photos were taken and reviewed with the patient, and the staff discussed the patient’s desires. Having patients evaluate themselves on large operatory monitor is very persuasive, helping the patient focus on what he or she does not like. The dentist reviews the photos again with the patient, explaining and discussing the case from a doctor’s standpoint.

In this case, the patient wanted her teeth to be in better alignment, to have the shade of her teeth improved, and to have a more youthful smile. The chairside team reports what they have learned to the doctor while the photo that best exemplifies most of the identified features that the patient did not like stays on the monitor for the patient to focus on while the doctor is briefed. Internally, we refer to this step as dwelling on the ugly.

The dentist then reviews the pictures again in front of the patient, pointing out things from the doctor’s perspective. The patient will often describe his or her desires differently to the doctor than to the clinical staff. This is where the tempering of expectations starts—to begin to curb patient expectations with regard to biologic, material, and technique limitations. It’s where desires meet reality.

Understanding Compromise
In this case, there was a missing left central incisor (tooth No. 9). A PFM bridge had been done to replace tooth No. 9, and the patient had a history of previous periodontal therapy. Her midline was off about 4.0 mm (to her right) and there was a slight cant in the PFM bridge (Figures 2 and 3). The composite veneers were leaking, with recurrent and interproximal decay on several teeth.

She had been missing tooth No. 9 for many years and had significant buccal plate and horizontal resorption. We offered the option of grafting and implant placement, and the patient declined. The pontic site would be compromised without ridge augmentation. If the patient should decline to accept recommended procedures, those compromises must be explained, understood by the patient, and documented.

After reviewing and agreeing that her gum tissue did not show in the photos, a compromise was agreed upon (this was the first compromise).

Tooth No. 7 was facially inclined and flared. We pointed out that the tooth may be a limiting factor in keeping the new restorations from looking bulky. The choices were extraction, an additional pontic, or implant placement. We agreed that leaving it in place, reducing what we could, and then evaluating the bulkiness of the temporary would be our plan. Another potential compromise.

When patients want whiter teeth, the challenge becomes what we will do with the lower teeth. She could not afford to veneer them, so bleaching was discussed. Promising the patient that we could predictably bleach her lower teeth to match her goal of 0M2 on the maxilla, a shade she chose with the assistant, would be misleading. Therefore, with her understanding, a slightly darker shade on the maxilla, 0M3, was chosen in case bleaching was not effective or maintained on the mandibular teeth. This was one more compromise chosen by the patient.

Figure 4. Lab team involvement with a detailed and shared understanding of the case is vital to success. A wax-up, reduction guide, and temporary matrix are all important communication tools. Figure 5. The lab team also provided a
soft-tissue modification plan that was created according to model/photographic analysis.
Figure 6. The diode laser (Picasso Lite [AMD LASERS]) was used to increase symmetry and to create more aesthetic soft-tissue contours. Figure 7. Decay removal, composite buildups, and consistent preparations are the basis for long-term success.
Figure 8. The preparations were checked using the lab-fabricated reduction guide. In this case, the position of the laterals were a potential aesthetic compromise if left in place. Figure 9. Preps were completed and a shade photo taken for the lab team.
Figure 10. Temporaries were made from the wax-up matrix in a shade that the patient desired as the final shade. Review was done 3 to 5 days after the preparation appointment, and the evaluation results were communicated with the lab team.

So what can’t we do? Pointing out the limitations of treatment versus her needs and wants must start early. It is important not to use words like permanent, exactly, perfect, and other words that imply that we will meet all the patient’s goals, regardless of biologic or material limitations. Everyone must be on board before treatment as to the degree of non-perfection that may be expected.

Lab Team Involvement
Having input from the dental laboratory team on a case like this is critical to the proper treatment planning of a comprehensive or cosmetic case. Often, the ceramist will come up with ideas to help treatment that the office team and doctor did not think of or consider. Having the lab team involved before beginning the actual clinical work obviously helps to make the treatment appointment more efficient, but even more importantly, there is the peace of mind that the clinician has by getting input from someone else about the case. It’s amazing how often the ceramist will think of something the doctor overlooked.

Alginate substitute (Silginat [Ket­tenbach LP]) was used to make accurate pre-op impressions. These were sent to the lab with a full series of photos, bite registration, and our stated goals for the case. We also supplied incisor measurements and what we thought would be the correct incisal position.

The dental technician then waxed up the teeth, made prep reduction guides (Figure 4), and a soft-tissue modification plan (Figure 5) according to the photos and treatment goals sent. The soft-tissue modification plan provides the clinician a basic blueprint for precise diode laser tissue recontouring without regard to biologic limitations.

Review of Expectations Before Treatment
At a case presentation appointment (or on preparation day), the chairside team reviews the plan. The patient is reassured about making great choices with treatment and how excited the team is to provide treatment as agreed upon. In our practice, we don’t go into a great amount of detail about upcoming treatment, but instead, we do deliver a pleasant and positive outline of what will be done during the appointment. The staff is trained to talk to the patient about how meticulous and thorough the doctor is and that excellence is the goal of the entire team. The tone is that of positive reassurance.

Clinical Treatment
After the treatment review, the patient was given local anesthetic. After bone sounding with a sharpened periodontal probe, it was verified that soft-tissue recontouring could be successfully done using a diode laser (Picasso Lite [AMD LASERS]). The author’s goal is to keep the final restoration margins 2.5 to 3.0 mm from the bony crest to prevent biologic width violations and to prevent chronically red or inflamed gingiva. Other areas were also shaped; this was done according to tissue type, location, and restoration margin extension (Figure 6).

Depth cuts were made and tooth preparation completed. All corners were rounded and the preparations were smoothed (Figure 7). Then the reduction guide was inserted and the tooth preparations were inspected (Figure 8).

Figure 11. A zirconia framework (layered) bridge (Lava Plus [3M]) was made from maxillary cuspid-to-cuspid, with individual layered zirconia crowns (Lava Plus) on the maxillary bicuspids. Figure 12. After try-in, the restorations were cleaned (Ivoclean [Ivoclar Vivadent]).
Figure 13. The teeth were isolated and cleaned with pumice (Preppies [Whip Mix]) and then 2% chlorhexidine (Cavity Cleanser [BISCO Dental Products]). Figure 14. Retention to the large composite buildups (Core-Flo DC [BISCO Dental Products]) was increased using air abrasion with 50-µm aluminum oxide.
Figure 15. A dual-cure universal bonding adhesive (ALL-BOND UNIVERSAL [BISCO Dental Products]) was massaged onto the teeth and air-thinned. Figure 16. Cementation was done with a self-etch self-adhesive dual-cure resin cement (BeautiCem [Shofu Dental]).
Figures 17 and 18. Photos were taken and evaluated. Perfection was nowhere to be seen, but this case was a success nonetheless.
Figures 19 and 20. Because imperfections were identified and managed throughout treatment, the patient’s and treatment team’s expectations were met. Focusing on the negative must be minimized and the overall benefit must be learned to be accepted.

Both lateral incisors involved preparation challenges. Tooth No. 7 was too far facial, and to reduce it enough for 2.0 to 3.0 mm clearance was not possible without compromising its strength. Having discussed this issue previously with the patient, this made our decision to leave it under-prepared facially more acceptable, and we would re-evaluate this issue in the provisional restoration phase. Tooth No. 10 was in the center of the proposed contact between it and the pontic. To reduce the tooth so it fit into the proper position, it would have to be prepped into the pulp and reduced to the point of questionable bridge abutment support. The effect of this compromise could result in an incorrect midline or tooth proportions that would not be acceptable. In this case, the compromise was made by the doctor to add another abutment to the bridge and to evaluate this during the temporary restoration phase as well.

Shades of the prepared teeth were taken to help the ceramist in choosing opacities and final shades (Figure 9). Full-arch vinyl polysiloxane (VPS) impressions (Panasil [Kettenbach LP]), a bite registration (Futar [Kettenbach LP]) and alignment guides, and an articulation record (Kois Dento-Facial Analyzer [Panadent]) were all taken and sent to the lab team. A temporary was made using the lab-fabricated matrix using a composite material (Luxatemp [DMG America]) in the shade the patient chose for the final restorations.

The Temporary Restoration Phase
One of the most important steps in a complex case is the temporary phase. It allows the patient the chance to preview basic shape, size, color, and incisal edge position based on the lab wax-up. These living and modifiable transitional restorations give the patient a preliminary chance to view the size, shape, and color that we desired for the case.

Five days after the preparation appointment, the patient returned, and the temporary bridge was evaluated (Figure 10). The patient was asked about aesthetics, speech, comfort, length, and color. The patient then signed a shade agreement form of the final shade (the same, lighter, or darker than the temporary/transitional restorations). Any needed adjustments were made, then photos and impressions of the temporary restorations were taken and sent to the lab team along with a brief description of the patient experience/feedback.

Preparation compromises and their aesthetic effect were also evaluated in the temporary phase before the final restorations were made. In this process, there must be a shared understanding among the staff, the doctor, and the patient.

Restorations
A 6-unit layered zirconia anterior bridge (Lava Plus [3M]) was made along with layered zirconia (Lava Plus) bicuspids (Figure 11). The lab made them based on the wax-up and a few corrections we made in the temporaries. All restorations were tried in for fit and aesthetics, cleaned using a universal cleaning gel (Ivoclean [Ivoclar Vivadent]) (Figure 12), and then rinsed thoroughly and dried with oil-free air. The teeth were cleaned using flour pumice (Preppies [Whip Mix]) (Figure 13) and then 2% chlorhexidine (Cavity Cleanser [BISCO Dental Products]). The retention to large composite resin buildups (Core-Flo DC [BISCO Dental Products]) was increased using air abrasion with 50-μm aluminum oxide (Figure 14).

A dual-cure universal adhesive (ALL BOND UNIVERSAL [BISCO Dental Products]) was massaged onto the tooth surfaces and air-thinned (Figure 15), followed by cementation with a self-etch, self-adhesive, dual-cure resin cement (BeautiCem [Shofu Dental]) (Figure 16). (The bridge was cemented first followed by the bicuspids.) After cleanup of any excess cement, the margins were fully light-cured (Elipar S10 [3M]). Finally, the occlusion was checked and adjusted as needed, and then the restorations were polished (CeraMaster [Shofu Dental]).

Celebrating Victory
We emphasize the positive; it rubs off onto the patient. At the insertion and at follow-up appointments, everyone in the office tells patients how great they look. “Wow, that’s one of the best cases the doctor has ever done. You look terrific.” Of course, we listen to any patient concerns and address any identified issues, but the goal is to do our best to not allow patients to control the emotion in the office by dwelling on anything that seems less than perfect to them.

CLOSING COMMENTS
As doctors, it is so important to know that we all share the same issues. The difference is in how each of us chooses to handle them. Plan for success, use all your resources to do the best, and do not beat yourself up over imperfections. If the limitations of biology, materials, and patient expectations are handled from the beginning, tension levels after the case will be lessened (Figures 17 and 18). What makes a happy patient is for the team and doctor to listen, and then to effectively communicate to the patient what can and cannot be done. Then, thorough evaluation of photos, models, and planning with the lab team will reduce stress when the case is delivered (Figures 19 and 20).

If you follow the recommendations woven into this case report article, you will improve your patients’ satisfaction. Furthermore, it will help you be happier dentist who learns to take joy in the successes, dwelling less on the dissatisfaction that is sometimes found in any necessary compromises.

Acknowledgment
The author would like to thank the Pacific Aesthetic Continuum (thepac.org) for the principles used in this case and the Pacific Aesthetic Dental Studios for their excellent case planning and restorations.


Dr. Griffin completed a general practice residency and maintains a general practice in Eureka, Mo. He focuses his clinical efforts on efficiency in almost all phases of general dentistry while providing state-of-the-art care and services for affordable fees. He centers his teaching content on increasing practice efficiency and on predictable restorative dentistry techniques. He can be reached via email at This email address is being protected from spambots. You need JavaScript enabled to view it. or via the website eurekasmile.com.

Disclosure: Dr. Griffin reports no disclosures.

Other Articles By Dr. Griffin

Focus On: Regenerative Dentistry

Shade-Matching Challenge: A Single Central Incisor

Achieving a good color match when restoring a single incisor is probably among the most difficult aesthetic challenges for any dentist (Figure 1). While the latest technology can be found in most modern dental offices such as CBCT; laser; CAD/CAM; and less common, the more expansive spectrophotometric instruments;1 the vast majority of clinicians still conduct dental shade selection by using a nearby window for a natural light source or, if they are fortunate, pass the buck by simply sending the patient to the dental laboratory technician to take and map the shade. There must be a better way and, in the authors’ opinions and experience, there is! A simple and inexpensive handheld portable LED light source, the Rite-Lite 2 HI CRI Shade Matching Light (AdDent), is now available help achieve an excellent restorative shade match.2-4

Figure 1. Pre-op photos of mismatched crown on nonvital central incisor with gingival inflammation.

DESCRIBING A SHADE
Shade matching is an interdisciplinary process that requires the clinician to communicate with the dental laboratory team using a common language and images (shade-mapping and photographs). Thus, shade matching relies on perception and interpretation of the evidence.

Color, commonly referred to as the shade, is divided into 3 components.

  • Hue refers to the basic color (eg, red, blue, green).
  • Chroma refers to the intensity of the color (eg, fire-truck red versus pastel pink).
  • Value refers to the brightness of the color (eg, the range of gray from black to white).

All these components should not be overlooked, or else a wrong interpretation of color may lead to an undesired result. For example, how often have you told your ceramist to make the cuspids slightly darker when restoring an anterior case? However, your real intent was to make the cuspids warmer with more chroma but not darker (lower value).

It is important to realize that the correct language helps in the interpretation of the evidence. Acquiring the evidence relies on the physiology of our eyes and the transmitted light.5

How We Perceive Color
We perceive color using cone cells that are located in the fovea in the middle of the retina. Cone cells are few in numbers and are divided into 3 groups. Each group responds to a specific color: red, blue, or green.6 Cone cells fatigue extremely fast, since they are limited in number. For example, if you stare at a color, such as red lipstick, the red cone cells will shut down after 30 seconds. This will leave you seeing only the combination of colors provided by the green and blue cells. This is why it is necessary to create a neutral background for your eyes before selecting a shade. Ideally, the walls in the room should be gray or white. Ask your female patients to remove their lipstick and place a pale blue or grey bib over their clothes.7

How We Perceive Value
We perceive value (shades of gray from black to white) through rod cells. These cells are on the periphery of the retina and outnumber the cone cells by 30 times.

Rod cells do not fatigue as easily or as quickly as the cone cells. They can determine the difference in value without getting overworked, while the cone cells quickly fatigue and colors seem to blend together. This is why selecting the correct value on a shade is critical. If the value is correct, hue and chroma can be slightly off without affecting the final result.

While our eyes can differentiate between colors and value of an object, modifying the light source can affect the way our eyes perceive the color of the object.6

Color Rendering Index
The color rendering index (CRI) is the measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with an ideal light source (ie, the sun, as opposed to LEDs or fluorescent lamps). Therefore, a light source with a high CRI is desirable in color critical applications.8 Hence, in our practice we use the Rite-Lite 2 HI CRI Shade Matching Light. This tool is easy to use and highly effective, and will help to ensure a cosmetically pleasing restoration even when treating complex clinical cases.

Color Temperature
Each light source has its own individual color, called color temperature, which varies from red to blue. Sunsets, candle flames, and light from tungsten bulbs all emit light that is close to red, thus imparting a “warm” look to photos. On the other hand, clear blue skies give off a “cool” blue light.

Color temperature is recorded in Kelvin (K), the unit of absolute temperature. The color temperatures of cool colors, such as blue and bright white, typically have color temperatures of more than 7,000°K. Red and orange, with warmer color temperatures, have measurements near the 2,000°K mark. Many references on shade matching in dentistry suggest the use of 5,500°K north white light at 12:00 noon as the standard to be used for shade matching as a basis to taking a shade.9,10

Figure 2. Handheld Rite-Lite 2 HI CRI Shade Matching Light (AdDent).
Figure 3. Examples of shade taken in different color temperatures.
Figure 4. Final results—new crown on central incisor.

This handheld device provides 3 different light options to replicate the different sources of light that we come across on a daily basis (Figures 2 and 3). The 3 lighting modes are as follows:

1. Color corrected light at a color of 5,500°K. This represents north white light at 12:00 noon as the standard to be used for shade matching.
2. Incandescent room light at 3,200°K, found most commonly in many indoor environments.
3. Ambient light at 3,900°K, a combination of both indoor and daylight.

Metamerism
In the field of color science, there is a principle called metamerism. It is a phenomenon that occurs when colors change when viewed in different light sources. This means that if a shade is a perfect match, it should match in multiple wavelength spectra (ie, in different lighting environments). Making sure that the shade tab matches the tooth in all 3 light sources has the following purposes:

  • It helps prevent metameric mismatch, which is a phenomenon by which 2 objects may appear different under different light sources. The Rite-Lite 2 can be used also after bonding the crown in place to verify the shade under the different color temperatures.
  • It helps select the correct value. The low-intensity light is preferable to select the value as the high intensity may be too bright and wash out the value. A crown that looked good in the sunlight or in your office under a 5,500°K may end up looking different in the patient’s bathroom mirror at 3,200°K, resulting in a costly remake.

CLINICAL CASE EXAMPLE
A complex clinical case for which a single restoration needs to be replaced on tooth No. 9 (left maxillary central incisor) will now be briefly described.

The treatment plan included the preparation and placement of an aesthetic layered pressed porcelain full crown. It is worth mentioning that tooth No. 9 had a dark root with a gray hue permeating throughout the gingival area as well as gingival irritation and 5.0 to 6.0 mm periodontal pockets.

The shade that matched the tooth in all 3 settings was identified to be the 1M1 shade tab from the value-based shade guide VITA 3D-Master (VITA North America). In today’s dentistry, where the majority of shades selected are on the bright side of the color spectrum, selecting the correct value is critical. The ideal distance to select a shade using the Rite-Lite 2 HI CRI Shade Matching Light is 6 to 8 inches from the patient (Figures 2 and 3).

My golf analogy to matching a single central is that it is a par 3 hole. It takes 2 to 3 tries to get a good match. The result, when using this shade selection technology, is as close to a hole in one as one can get (Figure 4).

IN SUMMARY
As explained in this article, there are many factors to consider when matching the shade of a restoration to an adjacent tooth, especially in the aesthetic zone. The shade selection process entails more than simply picking the shade tab that looks the closest in color. It is important to look at shades under multiple lighting conditions with a high CRI light source to get the best match in several common lighting environments.

Acknowledgment
Dr. Berland would like to thank Sami Yared, CDT (president/owner of YDL Dental Laboratory, Carrollton, Tex) for the excellent aesthetic work exemplified in this case example.


References

  1. Chu SJ, Trushkowsky RD, Paravina RD. Dental color matching instruments and systems. Review of clinical and research aspects. J Dent. 2010;38(suppl 2):e2-e16.
  2. Chu SJ, Devigus A, Mieleszko A. Fundamentals of Color: Shade Matching and Communication in Esthetic Dentistry. Chicago, IL: Quintessence Publishing; 2004.
  3. Paravina RD, Powers JM. Esthetic Color Training in Dentistry. St. Louis, MO: Elsevier Mosby; 2004.
  4. Afrashtehfar KI. Increased predictability in tooth shade-matching. Oral Health. 2013;103:44-52.
  5. Jaju RA, Nagai S, Karimbux N, et al. Evaluating tooth color matching ability of dental students. J Dent Educ. 2010;74:1002-1010.
  6. Pitel ML. Optimizing your shade-matching success: tips, tools, and clinical techniques. Dent Today. 2015;34:116-121.
  7. Jun SK. Shade matching and communication in conjunction with segmental porcelain buildup. Pract Periodontics Aesthet Dent. 1999;11:457-464.
  8. Feng X, Xu W, Han Q, et al. LED light with enhanced color saturation and improved white light perception. Opt Express. 2016;24:573-585.
  9. Moser JB, Wozniak WT, Naleway CA, et al. Color vision in dentistry: a survey. J Am Dent Assoc. 1985;110:509-510.
  10. Martínez-Verdú F, Perales E, Chorro E, et al. Computation and visualization of the MacAdam limits for any lightness, hue angle, and light source. J Opt Soc Am A Opt Image Sci Vis. 2007;24:1501-1515.

Dr. Berland is an internationally acclaimed cosmetic dentist and one of the most published authorities in the dental and general media. He is a Fellow of the American Academy of Cosmetic Dentistry (AACD); the co-creator of the Lorin Library Smile Style Guide as well as SEZI, Cosmetic Imaging Made Easy; the developer of denturewearers.com; and the founder of Dallas Dental Arts, a multidoctor specialty practice that pioneered the concept of spa dentistry. His unique approach to dentistry has been featured on 20/20, Dallas Morning News, Good Morning Texas, and in publications such as Time, Town & Country, Reader’s Digest, GQ, US News & World Report, Woman’s World, Details, D magazine, and more. In 2008, the AACD honored him with the “Outstanding Contributions to the Art and Science of Cosmetic Dentistry” Award. He can be reached via email at This email address is being protected from spambots. You need JavaScript enabled to view it..

Disclosure: Dr. Berland reports no disclosures.

Mr. Yared is president/owner of YDL Dental Laboratory in Carrollton, Tex. After earning an associate’s degree in applied science, he qualified as a certified dental technician and learned about function and occlusion from Dr. Niles Guichet at the University of Southern California. He also attended the Pankey Institute. He has worked with experts such as Masahiro Kuwata, Willie Geller, and Claude Sieber, and he has completed a master’s course in porcelain at VITA’s porcelain plant in Germany. He is a charter member of the Dallas Study Club (a division of the Seattle Study Club), the Dallas Implant Study Club, and many others. The YDL employs a philosophy that combines old world craftsmanship, value, reliability, service, and guarantees with new world technology and science. Mr. Yared’s pride in his products and the employees that produce them is reflected in the ongoing continuing education he provides for both his clients and staff. He can be reached at (888) 567-4935 or via email at This email address is being protected from spambots. You need JavaScript enabled to view it..

Disclosure: Mr. Yared reports no disclosures.

Related Articles

Shade Selection and Communication: Four Pieces to a Puzzle

The Science and Color of Shade Selection in Aesthetic Dentistry

Improving Shade Communication

 



Dentistry Today is The Nation's Leading Clinical News Magazine for Dentists. Here you can get the latest dental news from the whole world quickly.