The Ultimate Guide to Chairside Tooth Whitening

September 24, 2012

A look at tooth bleaching essentials, challenges, ages and stages.

A look at tooth bleaching essentials, challenges, ages and stages.

Prior to initiating any form of tooth bleaching, a proper examination should be performed to render a proper diagnosis of the cause of discoloration.1 This examination includes a clinical intra- and extraoral examination as well as a screening radiograph. Any single dark tooth, no matter how subtle, also should have a radiograph to evaluate for abscesses, internal/external resorption or calcific metamorphosis. In the examination, the clinician will evaluate both the function considerations and the esthetic considerations of the patient. Here’s what you need to know:

Functional considerations
1. History of sensitivity - To develop plans for pre-treatment or treatment during bleaching to alleviate sensitivity.2  Five-percent potassium nitrate in a tray application for 10-30 minutes is the most effective treatment for any type sensitivity.3 Pre-brushing for two weeks with a potassium nitrate containing tooth paste also will reduce sensitivity4, as well as using a bleaching product with potassium nitrate contained in the product.

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2. Tray design - For full arch or single tooth tray bleaching5, as well as tray design features, such as whether the tray should extend onto tissue or have no contact, spacers on teeth, or no occlusal coverage. The lower the concentration, the better to be onto tissue to contain the material and for healthy gingiva6. Spacers aren’t needed to bleach, and tend to waste material.7

3. Day-time or night-time treatment wear - Plans for tray bleaching, which should be appropriate for the type bleaching material, whether hydrogen peroxide or carbamide peroxide.8  HP works for only 30-60 minutes, so it is best for day, but takes more days than CP, which is active up to 10 hours, and is best overnight, or several hours per day. CP overnight takes less days to bleach than HP during the day, but more wear time per day.

4. Other appliances - Worn with tray bleaching, such as orthodontic appliances or removable partial dentures. Impressions for the trays may be with or without the other appliance, depending on when the patient will be bleaching.

5. In-office or tray - Are in-office multiple visits9  more appropriate than tray bleaching? Or a combination of tray and in-office treatment, depending on the patient’s lifestyle and financial situation.10

6. TMJ problems - May be aggravated by tray wear, or extended opening during in-office bleaching. Tray design can avoid occlusal coverage11 and in-office should be in shorter multiple visits.

7. Pregnant patients - Not bleaching pregnant or nursing mothers for the psychological concerns related to birth issues, as well as pregnancy gingivitis and morning sickness. There’s no known danger to the fetus or newborn baby from bleaching.

Esthetic considerations
1. Compare - The color of the teeth to the color of the sclera of the eyes. The best esthetic outcome is achieved when those two match.

2. Determine - If the patient has a “gummy smile” and short teeth, because bleaching accentuates the gummy display. Periodontal therapy may be indicated.

3. Identify - Other restorations that are displayed in a full smile, because they won’t change color with bleaching.

4. Be aware of - Alterations in individual tooth gingival architecture that may be more noticeable to the patient after bleaching.

5. Note - Exposed root surfaces, which will not bleach. Additional periodontal therapy may be needed to obtain root coverage. Smile analysis determines if those areas show in a normal smile.
6. Check for - White spots, as they won’t change color, only become less noticeable as the remainder of the tooth whitens. Additional treatment may be needed such as abrasion or bonding.

7. Evaluate - Transparent areas of the incisal edge that may become more noticeable after bleaching, causing a “bluish look.” Evaluate by placing a white-gloved finger behind the teeth to see if the discoloration disappears, which indicates translucency.

8. Diagnose - Discolored gingival areas, which are the most difficult to bleach, especially with tetracycline-stained teeth. Tetracycline-stained teeth take from 1-12 months of nightly bleaching with an average of 4 months. Nicotine-staining takes 1-3 months. Average teeth take 3 days to 6 weeks. The patient’s tooth discoloration is more the determining factor than the product, which is why the diagnosis of the cause of discoloration is important.

9. Evaluate - Dark restorations on the lingual or occlusal of teeth in the smile, or on the inside of an endodontically treated tooth, which may alter the effectiveness of the color change. Those often are replaced prior to bleaching.

Once the proper diagnosis and considerations are determined, then the dentist can advise the patient whether he or she is a good candidate for bleaching, which type of bleaching may work well, and what to expect from bleaching.

One major challenge for bleaching is sensitivity. For the patient who reports a history of severe sensitivity, or previous sensitivity with previous bleaching, consider the following protocol. Using all steps is not necessary, but clinicians should be aware of different issues that promote sensitivity, and manage their patients appropriately. Even with these steps, some people are unable to bleach.

Sensitivity considerations
1.Never - Begin bleaching immediately after a prophylaxis, as this tends to increase sensitivity to both the tooth and the gingiva. Wait two weeks after a prophy to initiate bleaching. 2.After - The prophy, make the alginate impression, take the baseline shade and photographs, and have the tray fabricated. Use a soft tray material on a cast from an excellent impression.

3. Pre-brush - With a potassium nitrate containing toothpaste for two weeks prior to initiating bleaching, which is the time it takes for desensitizing toothpaste to work.

4. Empty tray practice - Have the patient wear the empty tray one or two nights to become comfortable with the tray fit and feel. This avoids confusion by the patient of the different sensations.

5. Full tray practice - Wear the tray with potassium nitrate toothpaste or material for one or two nights to become comfortable with the feel of pressure on the teeth and to reduce the excitability of the teeth.

6. Potassium nitrate materials - May be either OTC toothpastes, or professionally supplied products. Avoid toothpaste with Sodium Lauryl Sulfate (SLS), which removes the smear layer, and with Gluten, which may cause gingival irritation.

7. Begin - Bleaching (night versus shorter day) with a low concentration product containing potassium nitrate. A 10% carbamide peroxide is approximately 3.5% hydrogen peroxide, so a CP product is the lowest concentration available. The higher the concentration, the greater the sensitivity.

8. Continued brushing - With the desensitizing toothpaste during bleaching, taking care to use a soft toothbrush and use proper patient-demonstrated brushing techniques.

9. Use the tray delivery - Of potassium nitrate desensitizing materials as needed for 10-30 minutes when sensitivity arises, either before application of the bleaching material, after completion, or anytime the teeth become sensitive.

10. Alternate or skip days - If bleaching sensitivity continues, the patient should shorten treatment time from night to day, or shorter times during the day.

11. Avoid acidic drinks - Patients should not drink cola and fruit juices, all which have a low pH of 2-3 and remove the smear layer, causing sensitivity.

People of all ages can benefit from bleaching, as the smile has the most profound impact of any part of the body on a person’s appearance, and is the item most people are interested in improving. Older adults tend to appear 10 years younger with whiter teeth, which are often associated with positive descriptors like more intelligent, happier, fun to be around and sexier.

Young children can have some personality challenges when their permanent teeth erupt if discolored.12 Hence the ages for bleaching range from 10-to-80-plus-years-old. The techniques for bleaching a child’s teeth may be better served using a “boil and form” tray, because a child’s teeth in the mixed dentition stage will not stay the same for long.

Because bleaching material goes all the way through the enamel and dentin to the pulp, it will bleach under the gingiva to the CEJ on partially erupted teeth. Although children have large pulps, they have excellent blood supply due to open apices, so they seldom if ever have sensitivity. The safety to children has been reported in previous articles using 10% carbamide peroxide for throat irritations and in orthodontic treatment.14 A low concentration of carbamide peroxide with a tray extended onto the gingiva and no spacers is the appropriate technique for the 10-14 age range. Treatment time is usually less than two weeks, and could be day or night.

There are many other situations that lend themselves to bleaching, and many product options available. All bleaching tends to be more conservative and safer for the patient than more aggressive dental treatments, so bleaching should be the first consideration in any esthetic evaluation.

References
1. Haywood VB. Pre-Bleaching Examination Vital for Optimum Whitening. Compendium Cont Edu Dent. Jan 2012, 33(1):76-77.

2. Pashley DH, Tay FR, Haywood VB, Collins MA, Drisko CL. Consensus-based recommendations for the diagnosis and management of dentin hypersensitivity. Comp Contin Edu Dent (Spec Iss) 29(8): 1-35, 2008.

3. Haywood VB, Caughman WF, Frazier KB, Myers ML. Tray delivery of Potassium nitrate-fluoride to reduce bleaching sensitivity. Quintessence Int 2001;32:105-9.

4. Browning WD. Haywood VB. Hughes N, Cordero R. Prebrushing with a Potassium Nitrate Dentifrice to Reduce Tooth Sensitivity During Bleaching Evaluated in a Practice-Based Setting. Compendium 2010; 31(3):220-225.

5. Haywood VB, DiAngelis AJ. Bleaching the Single Dark Tooth. Inside Dentistry 2010;6(8):42-52.

6. Lazarchik DA, Haywood VB. “Use of tray-applied 10% carbamide peroxide gels for improving oral health in special care patients”. J. Amer Dent Assoc 2010; 141(6):639-646

7. Haywood VB. Are Reservoirs Necessary?. J Esthet Dent 1999;11(1):3.

8. Haywood VB. The “Bottom Line” on Bleaching 2008. Inside Dentistry 2008; 4(2): 82-89.

9. Haywood VB. In-Office Bleaching: Lights, Applications, and Outcomes. Current Practice 2009; 16(4):3-6.

10. Gottardi MS, Brackett MG, Haywood VB. Number of in-office light-activated bleaching treatments needed to achieve patient satisfaction.  Quintessence International, 2006; 37(2):115-120.

11. Robinson FG, Haywood VB. Bleaching and temporomandibular disorder using a half tray design: A clinical report. J Prosthet Dent 2000;83:501-3.

12. Haywood VB. Bleaching Children’s Teeth: Questions and Answers. Georgia Academy of General Dentistry Newsletter 2006; September: 4-7.

13. Haywood VB, Caughman WF, Frazier KB, Myers ML. Fabrication of Immediate Thermoplastic Whitening Trays. Contemporary Esthetics and Restorative Practice 2001;5(9):84-86.

14. Haywood VB. Orthodontic Caries Control and Bleaching. Inside Dentistry 2010; 6(4): 36-50.

15. Haywood VB, Yiming L Consultants on report: “Tooth Whitening/Bleaching: Treatment Considerations for Dentists and Their Patients”. ADA Council on Scientific Affairs, September 2009 (updated November 2010). http://www.ada.org/sections/about/pdfs/HOD_whitening_rpt.pdf accessed 8.14.201
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