Dr. Van Haywood is a nationally known expert on tooth whitening currently on the faculty at the College of Dental Medicine, University of Georgia. With over 20 years of experience both in research and clinically on patients, his opinions with respect to which products and techniques work best should be of interest to those considering tooth whitening. Before beginning any such procedure, he recommends a complete dental exam by a dentist complete with radiographs (x-rays) so a diagnosis of the cause of discoloration can be made and pathology ruled out.
Many over the counter products such as Crest Whitestrips contain hydrogen peroxide (HP) rather than carbamide peroxide (CP) generally utilized by dentists. Both whiten by oxygenating the tooth though sensitivity with the former is about three times greater than with the latter. For patients unable to tolerate such sensitivity, the use of toothpastes with 5% potassium nitrate and NOT containing sodium lauryl sulfate (SLS) for 2 weeks ahead of whitening may be quite effective in reducing discomfort. Additionally, placing such toothpastes (Sensodyne Pronamel for example) in the whitening tray 30 minutes before using the whitening agent will likely reduce sensitivity further. Dr. Haywood favors 10% CP because it has NOT been shown to damage the teeth or the gums even with prolonged use of many months and has been shown to be effective. Avoidance of acidic (low ph) foods like soda, juices, wine and yogurt before and after whitening also can reduce sensitivity.
The more whitening that needs to be achieved, the longer it will take….many months in some cases. Patients with tetracycline staining for example may require 9 months or longer of nightly whitening effort! In office one time use of higher concentration products does not appreciably change the time factor required to achieve whitening nor has it been shown that adding heat, light or lasers to the process makes much difference.
For patients with recurrent apthous ulcers (canker sores), Dr. Haywood suggests trying SLS free toothpastes (read the label!). Interestingly, 7 nights of 10% CP use is about equivalent to 16 days of Crest Whitestrips (6.5% HP). When comparing the cost of even prolonged home use of CP over many months with veneers or crowns, whitening is considerably more cost effective when successful.
Finally in orthodontic patients, the use of 10% CP can whiten teeth even with the braces remaining since the agent disperses all around the tooth AND under brackets within 10 minutes. Further, CP is an antiseptic (antibacterial) which is useful in orthodontic patients with gum inflammation and is also cariostatic (inhibits cavity formation) to a greater degree than chlorhexidene (Peridex for example). The use of CP in orthodontic patients with less than ideal hygiene appears to be justified according to Dr. Haywood.