by Shannon Brinker, CDA CDD

Treatments to improve the esthetics of discolored porcelain veneers caused by improper shade selection, technique-based failures, and staining over time have caused many clinical challenges.¹ Time consuming, costly, and often requiring further removal of sound tooth structure, solutions were often limited to further polishing of the porcelain, or more commonly, removal and replacement.¹ Although effective when improper shades were selected and improper techniques used, removal and replacement is typically not the ideal treatment for restorations stained from consuming various foods and beverages.¹

Typically in these indications, restorations were merely polished further and new layers of glaze added if needed.² Although this effectively removed stains from the facial surface of the porcelain, stains at the margins and interproximal areas remained challenging and detracted from overall esthetics.² Additionally, polishing older porcelain restorations may cause excess loss of material, fracture, and debonding in some cases.² Therefore, a new solution was needed to remove stains from the surrounding dentition and improve esthetics without negatively effecting the restorative material.²

Figure 1. Pre Operative Full Face.

Veneer Renewal

Offering a solution to the clinical challenges of removing stains from porcelain restorations, recent research has shown that custom whitening systems may be used to enhance the appearance of veneers.¹ Although the shades of dental porcelain cannot be whitened through conventional peroxide-based formulas, whitening agents do remove stains from the margins, interproximal spaces, and lingual surfaces of the dentition not covered by porcelain.¹ Improving the overall esthetic value of the restorations, Veneer Renewal treatment may be accomplished using a carbamide peroxide-based whitening system (Venus White – Pro, Heraeus, South Bend, IN), customized trays, and a block-out technique.

Figure 2. Pre-Operative retracted smile with shade tab B1.

The concept of Veneer Renewal is based on research by Haywood and Heymann, which demonstrated that the effectiveness of whitening agents is dependant on the percentage of peroxide and the amount of time the teeth are exposed to the whitening agent.^3-5 Similar to the protocol for tetracycline-stained dentition, block-out resin is placed on the lingual surfaces of the tray/affected dentition, the tray is placed intraorally, and whitening is completed during sleep for 2 weeks. Allowing the peroxide to remain in direct contact with the dentition, the Veneer Renewal technique effectively whitens the margins, lingual surfaces, and interproximal spaces that are not covered by porcelain. Increasing the value and esthetics of the veneers, the Veneer Renewal technique offers excellent results, without the need to remove and replace the restorations.

Figure 3. Direct Flow trays 3M.

Venus White – Pro

Setting new industry standards and outperforming traditional hydrogen peroxide – based products, the Venus White – Pro (Heraeus) custom take-home whitening system is available in 16% or 22% mint flavored carbamide peroxide formulas.^6,7 Additionally, a 35% formula will be available in the future for the most challenging cases. Mor

e viscous than previous generations of bleaching agents, Venus White – Pro adheres to the teeth to whiten more effectively.^6,7

Although it is not possible to whiten porcelain restorations, Venus White – Pro may be used to whiten the underlying tooth structure of veneers that have become stained over time.¹ Utilizing a specialized material to block-out the facial surfaces of the custom trays, the carbamide peroxide formula is exposed to only the interproximal spaces, margins, and lingual surfaces.^6,7 Removing stains from these areas and whitening the dentition, Venus White – Pro increases the esthetic value of porcelain veneers.^6,7 Further, this technique has proven useful in cases requiring whitening of tetracycline stained dentition.^6,7

Figure 4. Whitening Impressions with Flexitime Putty and Correct Flow Wash.

To limit incidences of sensitivity in any case, potassium nitrate has been included in the Venus White – Pro formula.^6-8 Although the percentage of peroxide is a contributing factor to sensitivity, the literature has demonstrated that sensitivity is a direct result of the duration of peroxide exposure to the dentition.^6,7 Consequently, the stronger the solution and the longer it is in contact with tooth surfaces, the greater the chance the patient will develop sensitivity.^6,7 Although a milder whitening agent, the 16% formula of Venus White – Pro has proven beneficial for patients who desire to whiten while they sleep.^6,7 Therefore, custom trays filled with 16% carbamide peroxide may be left on for an extended period, without increasing the risk of sensitivity.^6,7

Figure 5. Poured and Trimmed Maxillary Model with Block out resin placed on lingual.

Demonstrating similar results to in-office treatments, Venus White – Pro offers a more cost-effective solution that also allow

s patients to whiten according to their schedule.^6,7 Further reducing this cost, once custom trays have been fabricated from impressions of the patient’s dentition, the trays may be reused multiple times. If the patient wishes to whiten in the future, they need only purchase a whitening gel refill kit through their dental office.

Figure 6. Lingual spacing with the blockout resin.

Clinical Example

A 39 year-old female patient presented with porcelain veneers done by another dental practice placed 6 years prior. The patient wanted to have the restorations replaced but finically could not at this time, however her chief complaints were staining around the margins, interproximal areas, and an overall desire to brighten her restorations. Upon further examination, it was determined that the restorations showed no signs of marginal leakage, improper coloring, or failure, which made removal and replacement unnecessary. Therefore, whitening with a 22% carbamide peroxide-based custom take-home whitening system (Venus White – Pro) one hour a day for 14 days was suggested.

Although whitening would not change the shade of the restorations, the patient was informed that it would effectively remove stains from the areas not covered with porcelain and enhances the overall value of the veneers.

Technique

Prior to treatment, the patient’s oral health was first evaluated and X-rays of his dentition were taken to ensure no active caries were present. After being approved for whitening treatment by the dentist, an all-inclusive series of clinical photographs were taken, including a full-face, smile, and retracted smile with shade tab. To facilitate proper fabrication of the definitive whitening trays, an impression of the patient’s dentition was then needed.

Wearing powder-free nitrate gloves, equal parts catalyst and base of a heavy-body polyvinyl siloxane putty material (Flexitime Putty, Heraeus, South Bend, IN) were kneaded together per manufacturer’s instructions, and the putty was loaded in specialized impression trays (Direct Flow Tray, 3M ESPE, St. Paul, MN). Utilizing self-retentive fleece strips, Direct Flow Trays (3M ESPE) prevent movement of the material during impression taking and eliminate the need for tray adhesive.

Figure 7. Retracted smile for final results

Instructing the patient to not bite down, the impression material and upper/lower trays were placed on the patient’s dentition and molded around the lips, while continual and even pressure was applied to each tray for 20 seconds. The trays were then removed and the impressions evaluated for any missed areas, voids, or defects.

After the viability of the putty impressions had been confirmed, a light-body realign/wash impression material (Flexitime Light Flow, Heraeus, South Bend, IN) was spread over the entire surface, including the palatal area, of the upper and lower putty impression. The light-body loaded trays were then reseated on the patient’s dentition and molded around the lips, while pressure was applied. The final impressions were then carefully removed from the patient’s mouth and inspected for any missed areas, voids, or defects. Prior to custom tray pouring, the impressions were allowed to sit for at least 30 minutes.

Once the custom trays had been poured and allowed to cure, block-out resin was carefully placed on the lingual surface of the maxillary model and a upper tray was fabricated to hold the whitening agent in place on the anterior veneered teeth when the patient was sleeping.

Figure 8. Pre Operative Full Face.

Although the whitening system incorporated potassium nitrate in the formula, 22% carbamide peroxide whitening agent (Venus White – Pro) was used to further reduce the risk of sensitivity. The proper way to load both upper and lower trays was then demonstrated to the patient to prevent overloading. Because improper application often results in seepage, soft-tissue burns, and inconsistent whitening, it is necessary to demonstrate to every patient the proper way to load and place whitening trays.

After the trays were loaded and seated, the patient was asked to confirm the comfort of the trays to ensure proper fit. Prior to leaving, the patient was instructed to wear the trays for 1 hour a day for total of 14 days. Additionally, the patient was instructed to brush the trays every morning after treatment to prevent remaining whitening agent in the trays from burning the gingival tissues. The patient was then told to return to the office in 2 weeks.
After 14 days of whitening with the Venus White – Pro system, the patient returned to the office for follow-up and new shade tab photographs to compare his pre-treatment and post-treatment smile. Effectively removing stains from the interproximal spaces, margins, and lingual surfaces, the patient was very pleased with the increased level of brightness and enhanced esthetics of his porcelain veneers that were achieved through his Veneer Renewal treatment with Venus White – Pro.

Conclusion

Utilizing the concept of Veneer Renewal with Venus White – Pro (Heraeus), dental professionals may now offer patients a cost-effective and highly efficient treatment for discolored porcelain veneers. A conservative treatment concept, Veneer Renewal has proven to effectively whiten the margins, lingual surfaces, and interproximal spaces to enhance the value of the overlying porcelain veneers.1 However, patients must still understand that Veneer Renewal will not whiten or brighten the porcelain itself. ◊

References

1. Haywood VB. Frequently asked questions about bleaching. Compend Contin Educ Dent. 2003;24(4A):324-38.
2. Miller LM. Porcelain veneer protection plan: maintenance procedures for all porcelain restorations. J Esthet Dent. 1990;2(3):63-6.
3. Haywood VB, Heymann HO. Nightguard vital bleaching. Quintessence Int. 1989;20(3):173-176.
4. Haywood VB. Historical development of whiteners: clinical safety and efficacy. Dent Update. 1997;24(3):98-104.
5. Heymann HO. Facts and fallacies. Br Dent J. 2005;198(8):514.
6. Venus White Teeth Whitening System. (2010). Show the world you most beautiful smile. [Brochure]. Heraeus, South Bend, IN.
7. Venus White Teeth Whitening System. (2010) Teeth whitening options for patients and dentists. [White Paper]. Heraeus, South Bend, IN.
8. Tam L. Effect of potassium nitrate and fluoride on carbamide peroxide bleaching. Quintessence Int. 2001;32(10):766-70.