Cosmetic

Prerestorative Considerations for Cosmetic Dentistry

J.J. Salehieh, DDS; Rick Little, CDT; and Ken Frangadakis, DDS

Copyright 2002 Journal of the California Dental Association.

About the Authors:

J.J. Salehieh, DDS, is an adjunct assistant professor in the Department of Fixed Prosthodontics at the University of Pacific and maintains a private practice in Cupertino, Calif.

Rick Little, CDT, LVI Expert Technician, is on the staff of Cupertino Dental Arts, Cupertino, Calif.

Ken Frangadakis, DDS, is in private practice in Cupertino, Calif.

Helping patients improve their appearance with esthetic procedures can be very rewarding. Optimal esthetic results often require a multidisciplinary approach and sequenced care. Treatment planning with a team approach offers the potential for multiple perspectives and the best opportunity to achieve the optimal results.

Cosmetic dentistry has become an important part of many dentists’ practices. In this era of emphasis on fitness and personal appearance, baby boomers have reached an age where they have the discretionary income and desire to consider procedures to improve their appearance. Additionally, the availability of information through the media has made the public highly aware of and educated about esthetic dentistry. The general dentist is receiving more inquiries regarding cosmetic dentistry and those inquiries are leading to an increase in demands for cosmetic and adjunctive procedures.

Dental school curricula provide only an adequate background in the fundamentals of cosmetic materials, diagnostic analysis, and techniques. To further improve these skills, general practitioners need to consider taking continuing education courses, with an emphasis on extensive hands-on courses. Unfortunately, most courses do not focus adequately on the concept of the team approach to providing cosmetic dentistry. Optimal success in cosmetic dentistry comes not from individual effort, but from a collaborative team effort.¹ The general dentist must function as the team leader, coordinating the diagnosis, treatment planning, and treatment progress among all members of the team. These members may include any or all of the following: laboratory technician, periodontist, oral surgeon, orthodontist, and endodontist.

Prior to defining which members of the team are needed for a case, it is essential for the cosmetic dentist to gather the necessary baseline information. This includes:

* Full-mouth diagnostic radiographs;

* Pretreatment photo documentation;

* Mounted study cast; and

* Smile analysis incorporating the occlusion, gingival, and orofacial supporting tissue.

Once the baseline information has been gathered, a preliminary decision can be made as to the team members needed for the case. The cosmetic dentist must orient the patient as to why other members are being included on the treatment team. Referrals are then made. The baseline information will often be useful in providing valuable insights for team members as well as avoiding duplication of services. After the consultations, the cosmetic dentist will coordinate the findings and develop a consensus treatment plan. This paper will review the necessary baseline information and collaborative efforts that are often necessary when providing cosmetic dental procedures.

Radiographic and Photo Documentation

The first step for a proper diagnosis is the collection of radiographic and photographic records.

A full-mouth radiographic series of diagnostic quality is essential for the evaluation of caries, periodontal disease, and oral pathology. In cosmetic dentistry, information such as root length, interproximal bone height, and crown-to-root ratio are important in the event gingival reshaping is indicated. Signs of periodontal disease such as infrabony and osseous defects should also be noted.

Photo documentation is important in helping the treatment team evaluate the patient’s smile characteristics.² High-resolution digital photos or 35 mm slides permit magnification of images, which often reveals subtle details difficult to discern clinically. Not only can the images of the smile be scrutinized, but they can also easily convey valuable information to other members of the team. Figure 1 is an example of a patient that communicates the midline and incisal edge relationship to the laboratory technician. Photographs also give a realistic sense of color and texture of the teeth and surrounding soft tissue. These baseline photographic series are also useful for comparative purpose. Upon completion of the case, the "before" and "after" are useful to help the patient appreciate the esthetic transformation they have undergone (Figure 2). These photographs are also helpful for self-critique and patient education.

Diagnostic Casts Models

Pretreatment diagnostic casts are important for diagnostic evaluation and as a legal part of the patient record. Study casts should be mounted using a face bow and appropriate bite registration record. The casts are then duplicated for diagnostic wax-up. If bleaching of the teeth is planned, a third set is useful for the fabrication of bleaching trays.

The diagnostic wax-up is an important aspect of treatment planning.^3-5 With the wax-up, tooth shape, incisal edge position, relative tooth proportions and angulations, contact points, embrasures, midline, and the gingival architecture can be analyzed (Figure 3). The starting points of the diagnostic wax-up should be the midline.⁶ Whenever possible, the midline should be parallel and as close as possible to the midline of the face. A midline canted one way or the other is often the cause of failure in cosmetic cases. The diagnostic wax-up will not only help the clinician identify position, spatial, and angulation problems, but it is also useful in providing the patient with an image of the final product.

Initial Smile Analysis

The initial phase of the smile analysis begins with the laboratory technician using the collected data to create a diagnostic wax-up. This is the process of determining the tooth shape and position that best complements the patient’s facial characteristics. Patients who seek cosmetic dentistry are people who want to look younger and feel better about their smiles. A youthful smile is characterized by a bright white smile that shows plenty of tooth structure and provides adequate lip support. In a smile analysis, the central incisors are the focal point of design, and canines are the cornerstones to the buccal corridor. In discussing the creation of ideal central incisors, most dental literature refer to the golden proportions, which means that if one assigns a value of the width of the lateral as 1.0, the width of the central is 1.6 times the width of the lateral. The width of the mesial one-third of the cuspid is 0.6 times the width of the lateral. The length-to-width ratio is 80 percent. Most technicians use this rule as a guide but not as an absolute.

The second phase of the smile analysis is to check the wax-up with the patient present to see if the shape, length, and width of the wax-up will complement the patient’s facial features. This is a critical point in deciding if other adjunctive procedures, such as crown lengthening, may be needed. A splint fabricated from the diagnostic wax-up can be transferred to the mouth to help the patient visualize the final result.

The most important stage of the smile analysis is to evaluate the smile with the provisionals on the prepared teeth (Figure 4). The provisionals should duplicate the final diagnostic wax-up. Both the patient and clinician should assess the esthetics. The clinician should also check functional requirements such as phonetics, lip support, and occlusion. The height and symmetry of the gingival crest is evaluated in the context of the patient’s smile line. If adjustments are needed, the temporaries can be shortened in the mouth or lengthened by adding a flowable composite. It is vital that the patient is pleased with the shape and contour of the temporaries because they will serve as a template for the final restoration. Once everybody is happy, an alginate impression is sent to the lab.

Selecting the Team Members

Laboratory Technician

The laboratory technician is an important, yet often overlooked, member of the team. The lab technician utilizes the study models and photographs to develop various smile designs on the model. The technician’s job is to define the individual smile design. This is done by managing the embrasure spaces, line angles, and incisal edges of the diagnostic wax-up such that it is characteristic of a youthful smile. Embrasures get larger in the posterior direction. For many patients, tooth symmetry is critical. Upon completion, the diagnostic wax-up is jointly reviewed by the clinician and patient prior to the preparation date. The technician also helps in the fabrication of the template for provisionals. The provisionals should reflect what is present on the patient-approved diagnostic wax-up. The delivery of the provisionals permits a final evaluation prior to the definitive restorations. The technician’s efforts are critical to fabrication of the final restorations and the potential for treatment success. Regardless of the other team members’ efforts, if the porcelain is not of the highest quality, the case will fail; and ultimately, the general dentist will be blamed. Communication between the dentist and the technician is vital for the success of many cosmetic procedures.

Periodontist

The periodontist can contribute to case management through the development of ideal soft tissue-teeth relationship. With current techniques in cosmetic periodontal plastic surgery, the periodontist is capable of moving gingival tissue apically through crown lengthening or gingivectomy. Coronal positioning of the soft tissue can be done with the shifting or augmentation of gingival tissue. Soft tissue and ridge deficiency can be treated by various hard- and soft-tissue grafts. Ridge preservation procedures can also be valuable to prevent tissue collapse around extraction sites.

Oral Surgeon

The oral surgeon is included on the cosmetic team to help with skeletal problems that may be encountered. It is quite difficult to create an enhanced smile design on someone with a severe class 2 or class 3 malocclusion. The correction of a skeletal malocclusion may include orthognathic surgical treatment. The oral surgeon can perform various combinations of LeFort procedures, mandibular advancement/retraction, and chin augmentation/reduction. The goal of these procedures is to develop appropriate skeletal and soft-tissue support for the esthetic smile. If extractions are needed, it is important that the surgeon is aware of the dentist’s goals for ridge preservation and maintenance of gingival contours.

Orthodontist

The orthodontist’s contribution to the esthetic team effort is often in tooth positioning and site preparation. Teeth may be aligned in the ideal position for the final restoration. During the orthodontic treatment, it is also important that the teeth be intruded/extruded so that the gingival crests are in an ideal relationship to each other as well as the surrounding soft tissue, notably the lips. Orthodontic treatment is both costly and time-demanding. This may at time deter patients from this treatment modality.

Alternatively, there is "instant orthodontics,"⁷ the correction of dental misalignment through the use of veneers and crowns. This treatment may be aggressive and at times require therapeutic endodontic treatment. For correction of gingival contours, crown lengthening, or gingival augmentation, a periodontist may be needed. This is a viable alternative for patients who are not willing to trade the time for the conservative management of their malocclusion.

Endodontist

When cosmetic procedures are involved, it is particularly undesirable to have a tooth that is stained or highly discolored. The presence of metallic posts and long-term pulpal necrosis are situations in which discoloration occurs. The dark base color makes it difficult to obtain the translucency and vitality the dentist and patient are looking for. The endodontist is often included as a member of the cosmetic dental team because of the potential for these problems. In teeth that have large metallic posts and buildups, ^8-11 the root surfaces have a dark color due to the reflection of the post through the root surface. Often, the post can be removed atraumatically under a microscope and be replaced with a porcelain or fiber post. This allows a lighter color to shine through the root and makes it easier to mask any discoloration. Similarly, discolored teeth can be treated with root canal therapy and be internally bleached.

At times, all disciplines of dentistry need to be called on to obtain the optimal results. Being an elective procedure, cosmetic dentistry requires precision and superior esthetics by an often demanding patient. It is the cosmetic dentist’s responsibility to coordinate and lead the team toward this goal.

Clinical Cases

The following are three clinical cases that demonstrate how optimal esthetic results can be obtained through an interdisciplinary approach.

Case 1

A 16-year-old boy was seen on an emergency basis with his chief complaint being a fractured front tooth, incurred during an inline skating accident (Figure 5a.). On examination, it was observed that tooth #9 had a mesio-incisal fracture that ended at the crestal bone. A pulpectomy was done to relieve the patient’s pain and to give the team members enough time to review the case.

Due to the patient’s young age, the team decided to try to save the tooth with root canal therapy. Due to the lack of tooth structure for retention, crown lengthening was performed via orthodontic extrusion. Performing a conventional crown lengthening procedure with periodontal surgery was rejected because it would cause differences between the height of the gingival crests of the two central incisors. The advantage of orthodontic extrusion in this case was that the gingival crest of tooth #9 was relatively more apical than that of #8. With extrusion, the osseous-gingival complex was coronally positioned. Crown lengthening can be performed at the end of orthodontic treatment to even the gingival crests. Operationally, the extrusion procedure was preceded with a temporary composite build-up to permit bracket attachment.

After approximately one year, enough tooth structure was present to proceed with crown restoration. The tooth was prepared for a ceramic core and an impression was taken and sent to the lab. ⁸ A temporary post and crown was fabricated, and the patient was sent home. One week later, the ceramic core (Figure 5b) was bonded into the canal with resin bonding cement base and catalyst, along with bonding agent using a rubber dam. After the preparation was refined, another impression was taken for the all-ceramic crown, and a custom shade was taken with the help of the lab technician. When the patient returned 10 days later, the all-ceramic crown was bonded on with translucent shade resin bonding cement using bonding agent and a rubber dam.

A multidisciplinary approach to this case enabled the team to save the tooth and avoid an implant or bridge. The endodontist can critically evaluate the extent of the fracture and whether the tooth can be saved, and the periodontist and orthodontist can evaluate the best way to perform crown lengthening without compromising esthetics. This team approach provided the most esthetic and predictable result for the patient. (Figure 5c).

Case II

Short clinical crowns and excessive gingival display are a frequently occurring cosmetic problem. Clinicians must determine the cause of the shortness to determine the best course of action for the patient. The following two cases give different approaches to achieving this goal.

A 40-year-old female presented with her chief complaint being "my teeth are short and dark, and I hate the big space between my front two teeth" (Figure 6a). The clinical exam revealed a gummy smile with tetracycline-stained teeth. Additionally, there was a large diastema, which a previous dentist had tried to close with a direct bonding procedure. The papilla between tooth #8 and #9 was non-existent due to the high attachment of the thick fibrous frenum.

Phonetics plays a major role in any cosmetic work-up, and the location of the incisal edges of anterior teeth is crucial for achieving proper sounds. To find the right length of her anterior teeth, the practitioner asked the patient to recite several words with the letter "F" (fifty-five, firehouse, etc.). The patient’s upper anterior teeth slightly contacted her lower lip, showing that her incisal length was correct. Once this was known, it could be determined that to achieve more tooth in her smile, the team would have to address the gingival counters. Using this information and comparing the anatomical length of the anterior teeth to the clinical crowns using X-rays, it was determined that the cemento-enamel junctions of the teeth were quite subgingival. This problem could be corrected one of two ways: either by orthodontics or periodontal crown lengthening. The patient chose crown lengthening to shorten treatment time.

Study casts with the ideal tooth length were waxed up. The diagnostic wax-up also attempted to shift the gingival crest of the anterior teeth toward the midline. This would in effect close the diastema without having the two central incisors appear disproportionately wide in relationship to other anterior teeth. Once the patient approved the diagnostic setup, a vacuum splint was made to serve as a surgical guide for the periodontist. This guide is useful in defining the final gingival margin and how the gingival crest will be positioned. The splint ensured adequate osseous contouring is performed so the margins of the final case would not infringe on the biological zone of attached tissue. If there is not at least 2 mm between the osseous crest and the restorative margin, the gingival tissue will always appear inflamed, or the tissue may remodel such that the gingival margins become exposed. In addition to the crown lengthening procedure, frenectomy and papilla augmentation with a connective tissue graft was performed to give adequate bulk of gingival tissue to eliminate a midline "black triangle" space problem.

After approximately six weeks, a new set of models was taken. Working with the help of the lab technician and preliminary photos, the team decided to wax up the eight anterior teeth to achieve the correct tooth proportions. Prepping posterior to the canines allowed the lab technician to steal some space from the distal of the canines and the premolars, making the smile more proportional. If, for example, only the front six teeth had been prepared, the patient would have been left with enormously wide teeth. During the preparation, great care was taken to remove as little as possible from the mesial of the central incisors, while keeping in mind that the team wanted to sink the mesial margins subgingivally. This allowed the technician to pinch the tissue and helped close the diastema.

The success of the treatment approach is evaluated by temporaries, which act as templates. They can be adjusted to help attain the desired affect and then transferred to the lab via an alginate impression. The restoration we made out of all-ceramic porcelain crowns (Figure 6b).

The key to success on this case was the effective use of a diagnostic wax-up and casts. A surgical stent helped guide the periodontist at the time of surgery. The surgeon can determine where the apex of the gingival crest will be located by knowing the tooth size and position. The shifting of the teeth toward the midline to help close the diastema would have been very difficult to determine without a surgical guide. This case also demonstrates the advances that have been achieved in esthetic periodontal surgery. Soft-tissue deficiencies can also be corrected with soft-tissue grafts, and the gingiva can be positioned coronally with semilunar or connective tissue graft procedures.

Case III

A 30-year-old woman presented with the following chief complaint: "I would like to replace my old bondings so I can have longer, whiter teeth." A clinical exam revealed a class 1 malocclusion with a 2 mm overjet, 10 percent overbite, and a bilateral open bite. The teeth were short and stained by tetracycline (Figure 7a). The marginal gingiva was inflamed, it was believed, because the patient was a mouth breather. It was determined that the anterior teeth had not fully erupted. The patient chose to start orthodontic treatment rather than a full-mouth rehabilitation and periodontal crown lengthening.

The orthodontic treatment took almost one year to be completed; but, toward the end of treatment, a new challenge arose: The patient was getting married. The patient insisted on finishing the treatment as soon as possible. This changed treatment because the orthodontist did not have enough time to line up the gingival architecture. The patient was sent to the periodontist while in braces to finish elongating the teeth with crown lengthening (Figure 7b). After surgery, the orthodontist gave the case its final touches, and the patient was then sent to get prepared for eight anterior veneers.

It was paramount that the temporaries be closely watched to make sure the patient was comfortable with the new bite and elongated teeth. After the dentist and patient were satisfied, the results were transferred to the lab. Ceramic veneers were used to hide the tetracycline stains. The final restorations were bonded using a rubber dam and the resin bonding cement system (Figure 7c).

Summary

Esthetic dentistry is an art. In mastering this art, the clinician must think about strategies to ensure the optimal esthetic results. Mastery involves learning to collect baseline information, assembling a multidisciplinary treatment team, and coordinating the various diagnostic and treatment modalities. Though some of this strategy is introduced to during dental education, dentists need to hone these skills with additional training. As practitioners learn to develop these skills, their ability to provide the best cosmetic result possible will improve.

References

1. Ramsey C, Ritter RG, et al, Eight-handed dentistry: An interdisciplinary approach to full-mouth rehabilitation. Contemp Esthet Restor Prac 5:36-42, 2001.

2. Gallegos AG, Enhancing interprofessional communication through digital photography. J Cal Dent Assoc 29:752-7, 2001.

3. Rufenalcht CR, Fundamentals of Esthetics. Quintessence Publishing Co, Chicago, p 186, 1990.

4. Chiche GJ, Pinault A, Esthetics of Anterior Fixed Prosthodontics. Quintessence Publishing Co, Chicago, pp 121-3, 1994.

5. Rosenberg MN, Kaw HB, et al, Periodontal and Prosthetic Management for Advanced Cases. Quintessence Publishing Co, Chicago, pp 96-7, 1998.

6. Morley J, Eubank J, Macroesthetic elements of smile design. J Am Dent Assoc 132:39-47, 2001.

7. McCarthy J, Banking on a beautiful smile. Esthetique 34-40, Winter, 2000.

8. Gluskin AH, Ahmad I, Herrero DB, The aesthetic post and core: Unifying radicular form and structure. Pract Periodont Aesthet Dent 14:313-21, 2002.

9. Hornbrook DS, Hasting JH, Use of bondable reinforcement fiber for post and core build-up in an endodontically treated tooth: Maximizing strength and aesthetics. Pract Periodont Aesthet Dent 7:33-44,1995.

10. Paul SJ, Scharer P, Post and core reconstruction for fixed prosthodontic restorations. Pract Periodont Aesthet Dent 9:513-20,1997.

11. Behle C, Light-transmitting glass fiber reinforced composite build-ups for endodontic treated teeth. AACD J 13:22-32, 1997.

To request a printed copy of this article, please contact/J.J. Salehieh, DDS, 10383 Torre Ave., Suite I, Cupertino, CA 95014 or bubuj@earthlink.net.

Legends

Figure 1. A bite-stick registration is taken to help orient midline and bite plane during the model mounting process.

Figure 2a. Crowded anterior teeth with heavy staining and darkening due to root canal.

Figure 2b. Ten crowns realigning the anterior teeth for a pleasing smile.

Figure 3a. Diagnostic wax-ups are useful in analyzing cosmetic issues and for case presentation. A patient with peg lateral incisors and slight midline shift wishes to improve his appearance.

Figure 3b. A diagnostic wax-up was useful in defining the new midline as well as the relative tooth proportion and form. The wax-up was useful in providing the patient with a visual aid of the end product.

Figure 3c. The completed case.

Figure 4a. Large discolored composites with disproportional anterior teeth.

Figure 4b. Anterior temporaries, which are the template for the final restorations.

Figure 4c. The final restorations mimic the temporaries.

Figure 5a. Tooth #9 has a mesial fracture to the crestal bone.

Figure 5b. Placement of post.

Figure 5c. Postoperative picture of the bonded crown.

Figure 6a. Tetracycline-stained teeth with large composite bonding. The triangular space is residual space after the attempt to close the diastema with bonding. Note that the central incisors are disproportionately wide in relationship to the rest of the anterior teeth. Figure 6b. Placement of eight crowns after crown lengthening and connective tissue graft.

Figure 7a. Discolored composites with tetracycline staining and bilateral anterior open bite.

Figure 7b. Crown lengthening procedure performed toward the end of orthodontic treatment to expedite the development of appropriate gingival architecture.

Figure 7c. Eight veneers creating a proportional and pleasing smile.