Oral Health Group
Feature

Tooth Whitening: Opening the Gateway to Treatment

April 1, 2013
by Robert A. Lowe, DDS


INTRODUCTION
The demand for tooth whitening continues to increase in the dental consumer marketplace. Whitening is available as an in-office treatment, as a take-home treatment utilizing custom fabricated trays, or with many over the counter products available via retail outlets. Cosmetic dental procedures, such as indirect veneers and direct bonding have been available to the patient population as well for more than 30 years. The desire for dental patients to enhance the aesthetics of their smiles is not diminishing. Recent estimates indicate that Americans are spending over 1.4 billion dollars annually on tooth whitening, utilizing various take-home, in-office and over the counter strips, trays and brush-on products alone. It is agreed by most professionals that maximizing results and minimizing potential side effects are best accomplished when whitening procedures are provided and monitored in the dental office. Aesthetic restorative procedures, which can not only brighten the smile, but also correct tooth positions, replace old fillings, and eliminate dental caries at the same time, are wonderful options, but usually more costly for the patient. Tooth whitening remains very cost effective and can be used as an entry point for many patients seeking aesthetic changes to their smile. It can also be used effectively in conjunction with restorative techniques to enhance the smile in a more conservative fashion by minimizing the number of teeth that are treated restoratively, yet maximizing the overall result and reducing the overall cost of treatment.

COMBINING TOOTH WHITENING AND AESTHETIC RESTORATIVE PROCEDURES
The desire for straight, bright teeth is a goal shared by most dental patients today. The first “aesthetic dentists” were really the orthodontists. Their goal was to straighten teeth to make the smile “look better”. It was also a goal of orthodontic treatment to correct dental malocclusions at the same time. In the early seventies, it was discovered that peroxide solutions used by periodontists to manage “gum disease” had an interesting “side effect”. These solutions often made the teeth appear brighter. Hence tooth whitening was born. Whitening procedures today can help us create beautiful aesthetics and allow us to be more conservative with the restorative procedures that are necessary to correct dental health issues. Once a patient decides they want brighter teeth, it opens up a whole new dialogue with them. Since existing restorations won’t respond to whitening, it means they will need to be remade once the remaining natural teeth are whitened. If a patient only requires straightening their teeth and brightening the color, then braces and tooth whitening are a conservative way to accomplish that result. If a brighter, straighter smile is desired and the patients’ teeth have some existing tooth colored fillings, veneers, or crowns, these will need to be upgraded to match the color after tooth whitening has been completed.

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CASE #1: A PATIENT IN TREATMENT WITH CLEAR ALIGNERS
The patient in Figure 1 presented with an unfinished result from aligner treatment. She is not happy with the way the treatment is going and is desiring a treatment alternative that will give her a brighter, straightened smile in less time than her current treatment regimen is taking. A desire to have “whiter, straighter teeth has brought the patient to this point. After the initial patient interview, it is discovered that although the patients’ chief desire was to “brighten her smile”, this complaint was not addressed and the patient was put immediately into clear aligners. She is not seeing the result she envisions. It is important to realize that a patient does not always know what they want until they see what they don’t want. After further discussion, it is noted that there are other aesthetic problems. There is gingival display and asymmetric gingival levels, and the shape of the maxillary central incisors is too square. The chief complaint of the patient which started with tooth color and whitening moved into a discussion of gingival aesthetic crown lengthening, minimal and “no prep” veneers for the maxillary arch, and in office tooth whitening to match the mandibular arch to the desired shade of the indirect labial veneers for the maxillary teeth. In other words, the desire for tooth whitening, had opened the patient to consider a more comprehensive approach that would yield a result that she would be much more happy with in the end.

THE MAXILLARY ARCH TREATMENT PLAN AND EXECUTION
The patients’ arch form is not too bad except for the minor rotations of the lateral and central incisors (Fig. 2). She has expressed the desire not to continue with the orthodontic treatment, since she will need a restorative solution to end up with proper width to length ratios and gingival zenith positions for her maxillary anterior teeth. The “ideal” width to length ratio for a maxillary central incisor is 75-80%. In other words, a ten-millimeter long maxillary central incisor should measure about eight millimeters mesio-distally at the contact area. A surgical plan is “mapped” out using a fine tipped marker (Fig. 3). The cervico-incisal heights of the central incisors should be positioned about one millimeter apical to the lateral incisor zeniths. The heights of contour of the free gingiva should be located at the disto-labial line angles of the facial surface. A diode laser (NV Laser: Zila Dental) is used to sculpt the free gingival tissue to the desired positions (Fig. 4). It should be noted that preoperative measurements were recorded measuring the depth of the gingival sulcus, then sounding to the crest of bone, to determine how much free gingiva could be safely removed without violating the biologic width. Figure 5 shows the heights of the free gingival tissues after correction with the diode laser. Note that a minor zenith correction was also performed at gingival level of tooth number eleven. This case was planned as a “no prep” veneer case. In actuality, some minor rounding of line angles, particularly the mesial corners of the central incisors, and the distal corner of the left lateral incisor were rounded with a diamond instrument to allow for alignment correction with the restorations. No provisionalization was required, since these minor contour changes were all in enamel. Per the treatment plan, the mandibular arch was whitened using ZOOM WhiteSpeed (Philips) in office tooth whitening. Figure 6 shows the isolation of the soft tissues and application of the whitening gel on the mandibular teeth. The master impression of the maxillary arch, along with an opposing impression and facebow transfer with centric bite record are sent to the laboratory for the fabrication of the veneer restorations (Pearlfect Smile: Mizrachi Dental Laboratory, Reynoldsburg, OH). The following visit, the Pearlfect veneer restorations are delivered to the patient. Figure 7 is a retracted intraoral view of the finished result: Pearlfect veneers on the maxillary arch and ZOOM whitening on the mandibular arch. The completed maxillary occlusal view is shown in Figure 8. Compare to Figure 2 to see that the minor tooth rotations are corrected, as well as the other aesthetic parameters. The final “smile photo” is shown in Figure 9, a beautiful combination whitening and veneer case, which began with a patient inquiring about tooth whitening options.

CASE #2: THE FOUR VENEER CASE
The patient in Figure 10 presented with a chief complaint that “her veneers on the upper front teeth were turning darker.” She was also displeased with the shapes of the lateral incisors particularly tooth number 7 and had expressed a desire for whiter teeth in general. Since overall, the desire of the patient was to have a brighter smile, tooth whitening was the most conservative alternative to achi
eve that result. After removal of the existing porcelain veneers and provisionalization with a rubberized urethane temporary material (Tuff Temp: Pulpdent Corporation), ZOOM chairside tooth whitening (Philips) was performed on the remaining natural teeth to assess the degree of whitening that could be achieved prior to remaking the porcelain veneers. Figure 11 shows the isolation performed for the chairside whitening procedure to protect the intraoral and perioral soft tissues. A liquid dam material is applied to protect the gingival tissues then light cured (Fig. 12). After placement of the whitening gel (Zoom WhiteSpeed 25% H2O2: Philips) on the facial surfaces of the teeth, the ZOOM WhiteSpeed LED light is positioned in place to activate the whitening gel. The Zoom WhiteSpeed LED light works to make the hydrogen peroxide more effective at breaking down stains (double carbon bonds) held within the dentin portion of the tooth. The yellow stains in the dentin absorb blue light from the lamp.

This absorption of light adds energy to the chemical reaction between the double carbon bond and the hydroxyl radical (from the breakdown of the hydrogen peroxide therefore, the yellow stains are eliminated more effectively when the blue light is used in conjunction with the whitening gel. Figure 14 shows the blue light is action. Since the patient had some gingival recession, the light was set on a medium setting to minimize the chance of postoperative sensitivity. The patient will also receive ACP Relief gel and custom trays in case there is some transient temperature sensitivity after the in office whitening visit. One of the nice features of the ZOOM WhiteSpeed LED lamp is that the intensity settings can be altered to deal with patients that have a tendency toward dentin hypersensitivity. After the in office treatment, the patient will continue with at home gel as needed for two weeks to maximize her tooth whitening potential. Two weeks after discontinuing at-home whitening, the patient is appointed to complete her porcelain veneers. This two-week period will allow a more accurate assessment of shade to be made at the master impression appointment. After removal of the provisional restorations, a preparation shade is taken using both the Easy Shade (Fig. 15) and the 3D Linear shade guide (Vident). The definitive restorations will be fabricated from E.max (Ivoclar Vivadent), so it is necessary to give the laboratory technician a preparation shade so they will know what color must be blocked out from underneath to achieve the final desired shade. A Stump Shade (Ivoclar Vivadent) is also taken to show the technician the approximate value of the preparation (Fig. 16). Figure 17 shows that the final shade is OM3, which is brighter than the brightest “natural” shade from the Vita Lumin shade guide, B1. Using a two-cord retraction technique, the top #1 braided cord (UltraPak: Ultradent) is removed, the more apical #00 braided cord is left in place. Figure 18 shows “the moat around the castle” as perfect retraction without bleeding is achieved with this technique. The light bodied impression material (Affinity Light Body XL: Clinicians Choice/Clinical Research) is syringed into the retracted gingival sulcus. An anterior Quad Tray (Clinicians Choice/Clinical Research) is used to deliver the impression material to the mouth and the patient is instructed to close into maximum intercuspation (Fig. 20). Note the use of lip retractors to help facilitate placement of the impression tray. Figure 21 shows the master impression made for the new porcelain veneers. Note that the light bodied impression material is not hydraulically pushed away, but completely surrounds the preparations. Once the dental technician completes the restorations, the case is delivered. Figure 22 shows the completed whitening and porcelain veneer case at the two week post operative visit. The remaking of the veneers with better morphologic shape, texture, and brighter value in conjunction with tooth whitening has given this patient the smile she has always wanted.

CONCLUSION
Two cases have been show where tooth whitening has played a significant role in achieving the overall aesthetic result for the patient. Tooth whitening, as an integral aesthetic procedure can “open the gateway” for a more comprehensive approach to treatment and at the same time, allow the dentist to be as conservative as possible in regard to the patient’s natural tooth structure. As patients demand brighter smiles, it is important to routinely offer tooth whitening as a coincidental procedure along with restorative therapy so that they can achieve their aesthetic goals and enjoy a bright, beautiful smile for many years to come!

ACKNOWLEDGEMENT
The author would like to acknowledge the artistry and expertise of Moshe Mizrachi of Mizrachi Dental Laboratory for the Pearlfect Smile provided in case number one, and of Krystyna Jasinski, CDT of Jasinski Dental Laboratory in Houston, TX for the beautiful ceramics provided in case number two.OH


Robert A. Lowe, D.D.S., F.A.G.D., F.I.C.D., F.A.D.I., F.A.C.D., F.I.A.D.E., F.A.S.D.A. Diplomate, American Board of Aesthetic Dentistry.