Applying Foundational Principles to Digital Technologies: Ensuring Success in Aesthetic Dentistry

INTRODUCTION
An increase in the popularity of aesthetic dentistry has resulted in the growing number of patients seeking dental treatment for the improvement of unaesthetic or compromised smiles.¹ Now patients not only visit dental offices for mere restorations of carious teeth but also for dental treatments that will enhance the aesthetics of healthy teeth.² Therefore, the professional approach of restorative dentistry has changed significantly with the development of new techniques augmented with advanced dental materials, enabling clinicians to achieve aesthetic improvements and aesthetically pleasing results.

The introduction and growth of digital technology has significantly impacted dental offices, leading to noteworthy changes in communication, accounting, and administrative functions.³ Compared with the early development of CAD/CAM dentistry in the mid-1980s, when design and processing of CAD/CAM technology was cumbersome and expensive, significant developments have been made in the last 5 to 10 years to accommodate new aesthetic trends as well as patients’ expectations.^4,5 Contemporary CAD/CAM systems (Figure 1) are not only efficient and productive; they are also accurate when used properly.⁶ Additionally, development of new (or improved) materials including aesthetic glass ceramics, high-strength ceramics, and composite resin materials (for both definitive and provisional restorations) has allowed clinicians to use digital dentistry for a growing number of clinical procedures⁷ with long-term clinical success.⁸ Therefore, the use of digital technology, advanced restorative materials, effective diagnostic and communication tools, and minimally invasive techniques (such as the Aesthetic Pre-evaluative Temporary [APT] technique [see the author’s 2-part article, “Discovering the Artist Inside” in the May and July 2013 issues of Dentistry Today]) enable clinicians to achieve highly aesthetic clinical outcomes that can surpass patient expectations while preserving tooth structure.⁹

The following clinical case report demonstrates the combined use of advanced digital technology and minimally invasive clinical techniques, providing consistent, predictable, and highly aesthetic results.

CASE REPORT
Diagnosis and Treatment Planning
A 32-year-old female patient presented with the chief complaint of a compromised smile. A “gummy smile” was immediately observed, and clinical evaluation revealed small clinical crowns with irregular incisal edges. Her periodontal condition was excellent and she had no significant medical problems. The patient’s dental history was excellent and she did not mention any known allergic reactions to any dental materials previously used. She was mainly concerned with her gummy smile and relatively short clinical crowns. Her treatment goals were to have a very natural looking smile, with longer length teeth and less gingiva showing.

Figure 1. The number of digital oral scanners being used by clinicians continues to grow.

Figures 2a to 2c. Preoperative pictures.

When making treatment-planning decisions for optimizing the aesthetics of a smile, it is important to take it into consideration that an ideal smile should be balanced; it should result in a decent display of teeth with a harmonious gingival architecture. Gingival asymmetries or excessive gingival display in the aesthetic zone can be corrected with minor periodontal surgeries or, when appropriate, with the use of laser. In clinical cases with a gummy smile, evaluation of the nature of the smile is important. If a gummy smile is limited to the anterior teeth, orthodontic intrusion of the anterior teeth may, when indicated, be the treatment of choice. However, if it is throughout the dentition, then periodontal or maxillofacial surgery can be considered among the available treatment options, depending upon the severity of the case.⁹

In order to offer the highest level of patient care, the clinician and the entire restorative team must be able to provide treatment that is biocompatible, functional, and predictably aesthetic. Therefore, initial communication with the patient is extremely important, allowing clinician to explain the treatment plan and to understand the patient’s expectations, and helping to ensure the best clinical outcome. Verbal communication alone is never enough, though; therefore, the utilization of an intraoral mock-up becomes important, allowing both the dentist and patient a way to visualize and evaluate a 3-D depiction of the shape, form, and contour of the initial smile design. In the present clinical case, preoperative pictures were taken (Figure 2) and treatment planning was discussed with the patient in detail.

After thoroughly evaluating this case, the treatment plan was discussed with the patient and mutually agreed upon. The plan would include crown lengthening of teeth Nos. 7 to 10 with a laser, followed by the aesthetic improvement of her teeth with monolithic lithium disilicate (high-strength ceramic) restorations.

Crown Lengthening Procedure
The first treatment step, in this case, was to minimize the gummy smile via crown lengthening of teeth Nos. 7 to 10. This was accomplished by repositioning gingiva in an apical direction using an ER,Cr:YSGG laser (Waterlase [BIOLASE]) (2,780 N) (1W, 35% water; 35% air, 20 Hz) (Figure 3). Prior to beginning this procedure, bone was sounded with a periodontal probe to be certain that the use of laser was an indicated technique for crown lengthening in this case. Therefore, 1 W wavelength with a G6 tip was used for soft-tissue lengthening and 1 W with a C3 tip for 3 mm facial bone recontouring through the sulcus.

Figure 3a. Crown lengthening was performed using an Er,Cr:YSGG laser (Waterlase [BIOLASE]) (2780N) (1W, 35% water; 35% air, 20Hz). Figures 3b to 3d. Post-op photos after crown lengthening.

Figure 4a. Mock-up started with the central incisors. Figures 4b and 4c. Completed composite mock-up.

Figures 5a to 5c. Diagnostic wax-up done by dental laboratory team.

Figure 6a. Digital scan of the unprepared teeth. Figure 6b. Digital scan of the wax-up models. Figure 6c. Superimposing of digital scans of unprepared teeth and wax-up model. Figure 6d. Designing the provisional restorations (APT) to be milled from Telio CAD (Ivoclar Vivadent) blocks.

Dental lasers offer a number of clinical advantages, including hemostasis, ability to seal nerve endings, lymphatic vessels, reduced postoperative pain and swelling, reduced bacterial counts, and a minimized need for sutures in most surgical procedures along with ease of use, high performance, and functionality.¹⁰ The patient was recalled after 4 weeks for follow-up. During the follow-up evaluation, an appreciable positive change in her smile was noticed. Not only was the excessive soft-tissue display minimized, but also better length-to-width proportion was achieved, already serving to improve her smile.

Direct Intraoral Mock-Up
The second treatment step in this case, following the completed laser surgery and healing period, was to create an intraoral mock-up. A direct intraoral mock-up was created by veneering, using a freehand technique, composite resin (Tetric EvoCeram [Ivoclar Vivadent]) onto the tooth surface without applying any adhesive bonding agent. The desired tooth form and anatomy were designed for optimal aesthetics using a nonstick sculpting instrument (OptraSculpt [Ivoclar Vivadent]); then, the composite resin was cured with a polywave LED curing light (bluephase G2 [Ivoclar Vivadent]). This procedure was repeated until all of the teeth being restored (teeth Nos. 7 to 10) had been designed (Figure 4).

Figures 7a to 7c. Aesthetic pre-evaluative temporaries (APTs).

Figures 8a to 8c. Tooth preparation through APT per prep dimensions required for restorative material being used.	Figures 9a and 9b. Facial and incisal reduction made with depth cutting burs. Pencil was used to pinpoint the depth created by depth cutting bur. Figure 9c. Pencil marks and tooth reduction after removal of APT.	Figures 10a to 10c. Tooth preparation was completed.

Intraoral mock-ups allow for the evaluation of the incisal length, facial volume, overall effect with facial profile, and the patient’s occlusion. In addition, it helps in communicating the proposed final aesthetic outcome to the patient, allowing one to make any necessary adjustments prior to performing any irreversible procedures.¹¹ Once the smile design had been discussed, adjusted, and agreed upon with the patient, an analog impression (Honigum [DMG America]) of the approved intraoral mock-up was taken. The model made from this impression would serve as a guide for the dental technician team as they further refined the details of the smile design during the creation of a diagnostic wax-up on the preliminary models. Also, an intraoral digital impression, before the fabrication of an intraoral direct composite resin intraoral mock-up, was taken using a digital scanner (CEREC Omnicam [Sirona Dental Systems]).

Figure 11a. Digital scan of the prepared teeth. Figure 11b. Digital scan of the wax-up. Figure 11c. Superimposition of digital scans of the prepared teeth and wax-up.

Although the whole smile design process actually starts with the direct mock-up that is created by the clinician and approved by the patient, it should also be emphasized that the laboratory team has a major role in achieving the desired aesthetic and functional success of the final restorations. This success is directly related to the dental laboratory team’s technical skills, ability to observe details, and creative artistry. Therefore, as another communication tool, it is important to document each step during the restorative planning and treatment process with excellent digital photography. Intraoral and facial profile pictures of the mock-up allow the dental technician team to comprehend the final aesthetic design, helping them in their goal to deliver the highest level of aesthetic restorations possible.

Figure 12a to 12c. Software image of restoration design and milled provisional restorations.

Figures 13a and 13b. Cementation of the provisional restorations was done using a spot-etch technique. Figure 13c. Patient’s profile picture after cementing provisional restorations.

So, at this stage in the patient’s treatment, the following information was shared with the dental laboratory team: an impression and model of the existing dentition; an impression of the mock-up to guide the dental technician for the wax up; an impression and model of lower dentition for articulation; photo-documentation along with digital video recording for smile relation; and an intraoral digital scan. Using these tools, the ceramist was then be able to fabricate a laboratory wax-up of the restorations with all the minute details required for optimal aesthetics (Figure 5). It should be noted that the incorporation of minute details of surface anatomy and tooth forms are helpful in milling aesthetically pleasing provisional restorations as well.

Aesthetic Pre-Evaluative Temporary Technique
As mentioned earlier in the author’s previous articles in Dentistry Today, there are 3 main advantages of using the APT technique: predictable aesthetics, proper occlusion, and phonetics. The APT technique allows the patient and clinician to successfully predict the aesthetic outcome, preventing patient concerns that may often arise after completion of the case. Additionally, the design can be adjusted and any limits in design choice due to functionality can be addressed. Verification of occlusion of the new design can be checked with the existing occlusion in terms of centric occlusion or maximum intercuspal position (MIP), canine guidance, and anterior guidance. Because the APT represents the final outcome, phonetics can also be evaluated in advance. This is an advantage not often considered, but it is extremely valuable.^9,12-14 Also, the thicker (additive) the APT is designed, the more minimally invasive the preparations will be.

Figure 14a. IPS e.max CAD (HT/Bleach 4 [BL4]) milled blocks (Ivoclar Vivadent). Figure 14b. Milled veneers before firing. Figures 14c and 14d. Note the partial prepless veneers on the mesial portion of the upper canines.

Figure 15a. IPS e.max CAD (HT/BL4) milled veneers before firing. Figures 15b to 15d. Milled veneers after fully firing.

Figures 16a to 16c. The ceramist applied various stains (IPS e.max Crystal [Ivoclar Vivadent]) for optimal aesthetics.	Figures 17a and 17b. Appearance of the monolithic lithium disilicate restorations in (a) transmitted light, and in (b) reflected light.

Figures 18a to 18c. Completed stain and glazed monolithic disilicate (e.max CAD) restorations on model.

Figures 19a to 19c. Final intraoral results.

Figure 20. Our smiling and very happy patient!

The wax-up was digitally scanned with the CEREC Omnicam. Next, the 2 digital scans (intraoral and wax-up) were superimposed, and then the APTs were milled (CEREC inLab [Sirona Dental Systems]) using provisional material blocks (Telio CAD [Ivoclar Vivadent]) (shade LT A1) (Figure 6). Once the teeth were spot etched, adhesive was applied to the etched areas only and the APTs were placed. Then, the proposed aesthetic outcome, occlusion, jaw relations, and phonetics were verified, discussed, and approved with the patient’s participation (Figure 7). Important note: If no adjustments are needed, the dental technician can use the digital scan of the first wax-up as a guide for milling the final porcelain veneers. In the present case, the patient was pleased with the look of the proposed final outcome and approved the smile design.

Tooth Preparation
The next step in the restorative procedure is tooth preparation. For clinical success of aesthetic restorations, it is very important to prepare teeth precisely and in a minimally invasive way without compromising the manufacturers’ preparation recommendations specific to the materials being used.^12,13 Using the APTs, clinicians are able to prepare minimally invasive preparations with precision. In the present case, with the APT in position, depth-cutting burs (828.31.022 [Brasseler USA]) were used to create the accurate horizontal groves; 0.3 mm at the incisal third and 0.5 mm at middle and incisal third (Figure 8). Pencil markings were used to pinpoint the depths created by depth cutters, and then vertical 1.5-mm depth grooves were created incisally (Figures 9a and 9b). Once the APT was removed, the pencil marks were used as depth guides (Figure 9c). The facial surfaces of the teeth were then prepared with diamond burs (6856-021 [Komet USA]), followed by smoothing the preps with polishing burs (8855-025 [Komet USA], 171504-025 [Accurata] and discs (Sof-lex [3M ESPE]) (Figure 10). Next, the prepared teeth were scanned using the CEREC Omnicam, and an intraoral scan of the prepared teeth was then superimposed with digital scan of wax-up model (Figure 11).

Provisional and/or Definitive Restoration Fabrication
At this stage, the clinician has 2 options: either the definitive lithium disilicate restorations (IPS e.max CAD [Ivoclar Vivadent]) can be immediately milled for adhesive cementation during the same dental visit (for those offices equipped with chairside milling), or the provisional restorations can be milled and temporarily cemented, assigning the task of fabricating the definitive restorations to the dental laboratory team. The dental ceramist can enhance the aesthetics of the monolithic lithium disilicate restorations using a stain and glaze technique or, if preferred, by utilizing a cut-back-and-layer technique with feldspathic porcelain applied in layers over the monolithic ceramic surfaces. In this case, it was decided to mill the temporary restorations using a provisional material (Telio CAD) (Figure 12). The temporary restorations were then luted using a spot-etching technique with a dual-cured resin provisional cement (Telio CS Link [Ivoclar Vivadent]) (Figure 13). Our dental laboratory team would do the technical work required to fabricate the definitive all-ceramic restorations.

Dental Laboratory Protocol
The definitive restorations (IPS e.max CAD HT Bleach 4 [Ivoclar Vivadent]) were milled (Figure 14), pre-sintered (Figure 15a), and then tried on the model; followed by fully firing the restorations in the furnace (Programat CS [Ivoclar Vivadent]). The restorations were then tried in on the model again (Figures 15b to 15d). After verifying fit and accuracy of the fired restorations on the working model, various stains (IPS e.max Crystal [Ivoclar Vivadent]) were applied by the ceramist to enhance the anatomical and aesthetic features in the restorations (Figure 16). (Blue stains were used to create a translucency effect, white stains were used to soften the translucency effect, followed by the addition of orange shades to add opalescent effect to the restoration.) Next, the restorations were glazed (IPS e.max Crystal Glaze [Ivoclar Vivadent]). The high aesthetics of the final stained and glazed restorations were appreciated in both transmitted (Figure 17a) and reflected light (Figure 17b).

Delivery Appointment
The restorations were tried on the master model (Figure 18) and in the mouth to check for accuracy, fit, and the final aesthetic outcome; no adjustments were required. The author prefers to acid-etch all-ceramic restorations after the intraoral try-in, so at this point, the internal aspects of the lithium disilicate restorations were carefully etched with 5% hydrofluoric (HF) acid (IPS Ceramic Etching Gel [Ivoclar Vivadent]) for 20 seconds, to maximize the cement-to-restoration bond strength and to clean the restorations. The acid gel was then rinsed out of the restorations thoroughly with water, and the restorations were kept in an alcohol bath for 5 minutes. Note: If the restorations in your practice come from a commercial dental laboratory and are already HF acid etched, then one does not re-apply HF acid gel a second time. Also, after try-in of restorations that are previously etched, a universal cleaning paste (Ivoclean [Ivoclar Vivadent]) is applied for 20 seconds, rinsed, and dried, and then a universal primer is applied and dried. Next, a universal primer (Monobond Plus [Ivoclar Vivadent]) was applied for 60 seconds, and then thoroughly dried. These steps were immediately followed by adhesive bonding of the all-ceramic restorations with a light-cured resin cement (Syntac Adhesive System with Variolink Veneer cement [Ivoclar Vivadent]), using an LED curing light (bluephase G2 [Ivoclar Vivadent]) (Figures 19 and 20).

CLOSING COMMENTS
The basic fundamentals for predictable clinical success in aesthetic dentistry include planning and design in advance, detailed communication with both the patient and dental laboratory team, using minimally invasive techniques and advanced technologies, and the selection of ideal materials that have the required mechanical and physical properties to complement the clinical requirements that are specific to each case.

The use of digital technology offers innovative workflow for implementing advanced digital solutions for patient treatment, and using clinical procedures like the APT technique help achieve clinical results that are both extremely accurate and minimally invasive. Following consistent and thoughtful clinical procedures, as demonstrated in this case report article, can consistently provide predictable aesthetic and functional outcomes for your patients.

References

1. Peumans M, Van Meerbeek B, Lambrechts P, et al. Porcelain veneers: A review of the literature. J Dent. 2000;28:163-177.
2. Reinhardt JW, Capilouto ML. Composite resin esthetic dentistry survey in New England. J Am Den Assoc. 1990;120:541-544.
3. Fasbinder DJ. Computerized technology for restorative dentistry. Am J Dent. 2013;26:115-120.
4. Miyazaki T, Hotta Y, Kunii J, et al. A review of dental CAD/CAM: Current status and future perspectives from 20 years of experience. Dent Mater J. 2009;28:44-56.
5. Schoenbaum T. Dentistry in digital age: An update. Dent Today. 2013;31:112-113.
6. Ellingsen LA, Fasbinder DJ. In vitro evaluation of CAD/CAM ceramic crowns [abstract 2641]. J Dent Res. 2001;81:331.
7. Fasbinder DJ. Materials for chairside CAD/CAM restorations. Compend Contin Edu Dent. 2010;31:702-709.
8. Guess PC, Selz CF, Steinhart YN et al. Prospective clinical split-mouth study of pressed and CAD/CAM all ceramic partial coverage restoration: 7-year results. Int J Prosthodont. 2013;26:21-25.
9. Gürel G. The Science and Art of Porcelain Laminate Veneers. Chicago: Quintessence Publishing Co; 2003.
10. Lomke MA. Clinical applications of dental lasers. Gen Dent. 2009;57:47-59.
11. Ferencz J, Fanetti P. MasterClass: Enhanced communication. Inside Dental Technology. 2001;2:44.
12. Gürel G. Discovering the artist inside: A three-step approach to predictable aesthetic smile designs, part 1. Dent Today. 2013;32:74-78.
13. Gürel G. Discovering the artist inside: A three-step approach to predictable aesthetic smile designs, part 2. Dent Today. 2013;32:126-131.
14. Gürel G, Morimoto S, Calamita AM, et al. Clinical performance of porcelain laminate veneers: Outcomes of the aesthetic pre-evaluative temporary (APT) technique. The International Journal of Periodontics & Restorative Dentistry. 2012;32:625-635.

Dr. Gürel graduated from the University of Istanbul Dental School in 1981. He continued his education at the University of Kentucky, department of prosthodontics, and received his MS degree from Yeditepe University, Istanbul. Dr. Gürel is the founder and the honorary president of EDAD (Turkish Academy of Aesthetic Dentistry). He served as the president of the European Academy of Esthetic Dentistry in 2010 and 2011 and is a member of the American Society for Dental Aesthetics, American Academy of Restorative Dentistry, and an honorary Diplomate of the American Board of Aesthetic Dentistry. He is a visiting professor of New York University, Marseille Dental University (France), and Yeditepe University (Turkey). Additionally, he is the author of The Science and Art of Porcelain Laminate Veneers (Quintessence, 2003), which has been translated into 10 languages. He can be contacted at the following e-mail address: dentis@superonline.com.

Disclosure: Dr. Gürel receives lecture sponsorship from DMG America and Ivoclar Vivadent.