Influence of the light source and bleaching gel on the efficacy of the tooth whitening process.
Domínguez A, García JA, Costela A, Gómez C. Department of Laser Chemistry, Rocasolano Institute of Physical Chemistry, CSIC, Madrid, Spain.
To examine the whitening efficacy of three whitening agents in combination with six different photoactivation systems.
Bleaching techniques have achieved significant advances using photoactivation with coherent or incoherent radiation sources.
Quick White, Ena White Power, and Opalescence Endo bleaching agents, all containing 35% hydrogen peroxide, were stimulated with halogen lamp, light-emitting diode (LED), low-power diode laser, and neodymium: yttrium-aluminum-garnet (Nd:YAG), second harmonic of Nd:YAG, and Er:YAG lasers. One hundred twenty-six extracted human incisors were treated, and color change, pulpal temperature, and enamel morphological alterations were evaluated.
Only the groups that were photoactivated using a diode laser, halogen lamp, and LED showed statistically significant differences (p < 0.005) in color change when compared with the control group (without photoactivation). All whitening protocols were safe with regard to the increase in pulpal temperature. Scanning electron microscopy showed no evidence of effects on the integrity of enamel.
The source of irradiation is more relevant than the bleaching agent for efficient tooth whitening. In addition, photoactivation with LED was found to be the best choice: it yielded significant change in color with only a minor increase in pulpal temperature.
IN VIVO DEGRADATION OF BLEACHING GEL USED IN WHITENING TEETH
BRUCE A. MATIS, D.D.S., M.S.D., UBIRACY GAIAO, D.D.S., M.S.D., DARRIN BLACKMAN, B.S., FRANKLIN A. SCHULTZ, PH.D. and GEORGE J. ECKERT, M.A.S.
The purpose of the study described here was to determine the in vivo degradation rate of 10 percent carbamide peroxide, or CP, gel in bleaching trays. The degradation rate indicates the remaining concentration of the active agent on the facial surfaces at various intervals.
The researchers fabricated bleaching trays with 0.5-millimeter reservoirs and loaded them with a 10 percent CP whitening gel. The tray was seated in place in 15 patients for six different intervals that ranged from 15 seconds to 10 hours. When the tray was removed, three samples were collected from each patient: the gel remaining in the tray; the adherent gel scraped from the teeth; and a “grab” sample from the reservoir of tooth no. 8. The researchers analyzed these samples for CP according to the method specified by the U.S. Pharmacopeial Convention.
The percentage of CP recovered decreased as the intervals increased: 87 percent at 15 seconds, 10 percent at 10 hours. Log of tray, teeth and grab samples, respectively, at 15 seconds were 0.94, 0.98 and 0.96 and at 10 hours were –0.13, –0.38 and 0.11. The first-hour degradation rate for tray, teeth and grab samples, respectively, was 2.0 times, 3.6 times and one time the rate during the next nine hours. The within-subject repeatability of the samples was excellent.
The degradation rate of CP during the bleaching process is biexponential. In the tray and teeth samples, the degradation rate was accelerated during the first hour. Further research is needed to determine the cause of this acceleration.
The active agent in CP bleaching gel is available in bleaching trays for more than 10 hours. After two hours, more than 50 percent of the active agent is available, and 10 percent is available after 10 hours.
Use of Tray-Applied 10 Percent Carbamide Peroxide Gels for Improving Oral Health in Patients With Special-Care Needs
David A. Lazarchik, DMD and Van B. Haywood, DMD
Plaque accumulation and resulting caries or periodontal disease is a frequent problem in patients with special-care needs. Tray-applied 10 percent carbamide peroxide (CP) is a tooth-bleaching agent that has positive effects on plaque, gingival health and caries.
The authors review the antibacterial properties of CP and the effects of CP on saliva, plaque, caries and gingival health. They also review tray fabrication options and techniques, application methods, safety and side effects. Finally, they address the challenges involved in and research needed regarding use of tray-applied CP materials in special-care patients.
In their literature review and clinical experience, the authors found 10 percent CP delivered in a custom-fitted tray to be an effective treatment for caries in patients with compromised oral hygiene. Plaque suppression and caries control result from a CP-induced increase in salivary and plaque pH caused by CP’s urea component, and from possible antimicrobial action via physical debridement and the direct chemical effect of hydrogen peroxide.
Tray-applied 10 percent CP may hold great promise for improving the oral health of many special-care patients, including elderly patients, patients with cancer and patients with dry mouth. Further research is needed to verify the potential benefits, specifics of treatment times and protocols and most cost-effective products for use in various patient groups.
Application of 10 percent CP in a custom-fitted tray may reduce caries by elevating the pH above the level at which the caries process can occur, in addition to debriding the teeth and improving gingival health.
Effects of experimental xylitol varnishes and solutions on bovine enamel erosion in vitro
Souza JG, Rochel ID, Pereira AF, Silva TC, Rios D, Machado MA, Buzalaf MA, Magalhães AC. Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
This in vitro study aimed to analyze the effects of application of xylitol varnishes and solutions to protect against enamel erosion. Twelve bovine enamel specimens were pre-treated with 5% NaF-Duraphat varnish, 10% xylitol varnish, 20% xylitol varnish, placebo varnish, 5% NaF solution, 10% xylitol solution or 20% xylitol solution. The varnishes and solutions were applied for 6 h and 1 min, respectively. Controls remained untreated (n = 12). Specimens were then subjected to erosive demineralization (Coca-Cola, 4 × 90 s/d) and remineralization (artificial saliva, 2 h) cycling for 10 days. After 5 days, the varnishes and solutions were reapplied. After reapplication, two specimens per group were analyzed by SEM. Enamel loss was measured profilometrically after the 5th and 10th days. Data were then analyzed statistically by ANOVA and Tukey’s post-hoc test (n = 10, P < 0.05). After the 5th day, all varnishes and 20% xylitol solution significantly reduced the enamel loss when compared to the placebo varnish/control. After 10 days of erosive pH cycling, both xylitol varnishes and solutions significantly reduced the enamel erosion when compared with the control. However, 10% xylitol solution produced a smooth layer on eroded enamel and significantly reduced the enamel erosion when compared to the placebo varnish/control. Xylitol thus appears to be a good option to partially reduce enamel erosion.
The use of sorbitol- and xylitol-sweetened chewing gum in caries control
Brian A. Burt, BDS, MPH, PhD
The author compared the caries-inhibitory action of sorbitol- and xylitol-sweetened chewing gum and assessed the role of these products in caries prevention.
TYPES OF STUDIES REVIEWED
The author reviewed studies including randomized field trials with substantial numbers of participants and observational studies. He did not review case studies. He found studies through a MEDLINE search and by hand searching.
When compared with sugar-sweetened gum, sorbitol-sweetened gum had low carcinogenicity when it was chewed no more than three times per day. Xylitol-sweetened gum was noncariogenic in all of the protocols tested. Some studies claimed that xylitol-sweetened gum had an anticariogenic effect, though these claims need further study. There also is good evidence that when mothers of infants and young children chew xylitol-sweetened gum, it will block transmission of mutans streptococci from mother to child.
The evidence is strong enough to support the regular use of xylitol-sweetened gum as a way to prevent caries, and it can be promoted as a public-health preventive measure. Chewing xylitol-sweetened gum, especially for patients who like chewing gum, can be fitted readily into a regimen that includes frequent fluoride exposure, good oral hygiene and regular dental appointments.
An In Vivo Study of the Effect of a 38 Percent Hydrogen Peroxide In-office Whitening Agent on Enamel
Milena Cadenaro, DDS, PhD, Chiara Ottavia Navarra, DDS, PhD, Annalisa Mazzoni, DDS, PhD, Cesare Nucci, MD, DDS, Bruce A. Matis, DDS, MSD, Roberto Di Lenarda, DDS and Lorenzo Breschi, DDS, PhD
In an in vivo study, the authors tested the hypothesis that no difference in enamel surface roughness is detectable either during or after bleaching with a high-concentration in-office whitening agent.
The authors performed profilometric and scanning electron microscopic (SEM) analyses of epoxy resin replicas of the upper right incisors of 20 participants at baseline (control) and after each bleaching treatment with a 38 percent hydrogen peroxide whitening agent, applied four times, at one-week intervals. The authors used analysis of variance for repeated measures to analyze the data statistically.
The profilometric analysis of the enamel surface replicas after the in vivo bleaching protocol showed no significant difference in surface roughness parameters (P > .05) compared with those at baseline, irrespective of the time interval. Results of the correlated SEM analysis showed no relevant alteration on the enamel surface.
Results of this in vivo study support the tested hypothesis that the application of a 38 percent hydrogen peroxide in-office whitening agent does not alter enamel surface roughness, even after multiple applications.
The use of a 38 percent hydrogen peroxide in-office whitening agent induced no roughness alterations of the enamel surface, even after prolonged and repeated applications.
The effect of at-home bleaching on the microhardness of six esthetic restorative materials
Olga Polydorou, DDS, Dr med dent, Elmar Hellwig, DDS, Dr med dent, PhD and Thorsten Mathias Auschill, DDS, Dr med dent, PhD
The authors conducted an in vitro study to evaluate the effect of an at-home bleaching product on the microhardness of six restorative aterials under different surface treatments.
Four resin-based composite materials (a hybrid, flowable, microhybrid and nanohybrid), an ormocer (organic modified ceramic) material and a ceramic material were bleached with 15 percent carbamide peroxide. The authors prepared two groups of samples (polished and unpolished) (n = 7) from each resin-based composite material and the ormocer. The authors polished all of the samples in the ceramic group. Two samples from each group served as negative controls. The authors measured the microhardness of the samples before bleaching, after eight hours and 56 hours of bleaching, and 24 hours and one month after the end of bleaching.
The statistical analysis showed that the at-home bleaching technique did not have a statistically significant effect on the microhardness of any of the restorative materials tested (hybrid, P = .0679; flowable, P = .5088; microhybrid, P = .0601; nanohybrid, P = .6166; ormocer, P = .2154; ceramic, P = .9943).
At-home bleaching with 15 percent carbamide peroxide did not cause any harmful changes to the microhardness of tooth-colored restorative materials.
Clinicians do not need to replace resin-based composite, ormocer or ceramic restorations after at-home bleaching treatment when the restorations are in posterior teeth
Carbamide Peroxide used in teeth whitening is safe. Over 800 references exist for studies that have been conducted.
DAVID C. SARRETT, D.M.D., M.S.
Methods to improve the esthetics of the dentition by tooth whitening are of interest to dentists, their patients and the public. In the past 20 years, research on bleaching and other methods of removing tooth discolorations has dramatically increased. Dentist-supervised and over-the-counter products now are available to solve a variety of tooth discoloration problems without restorative intervention. The indications for appropriate use of tooth-whitening methods and products are dependent on correct diagnosis of the discoloration.
Tooth-whitening methods include the use of peroxide bleaching agents to remove internal discolorations or abrasive products to remove external stains. Peroxide bleaching procedures are completed by the dentist in single or multiple appointments, or by the patient over a period of weeks to months using custom trays loaded with a bleaching agent. Both methods are safe and effective when supervised by the dentist. Microabrasion is indicated for the removal of isolated discolorations that often are associated with fluorosis. Whitening toothpastes remove surface stains only through the polishing effect of the abrasives they contain.
CONCLUSIONS AND PRACTICE IMPLICATIONS
Tooth whitening is a form of dental treatment and should be completed as part of a comprehensive treatment plan developed by a dentist after an oral examination. When used appropriately, tooth-whitening methods are safe and effective.
Since the introduction of the tooth-whitening technique that uses custom bleaching trays loaded with 10 percent carbamide peroxide gel 13 years ago,1 the demand for information on tooth bleaching and whitening has increased dramatically. When I conducted an online search of the National Library of Medicine’s MEDLINE database2 from 1969 to 1978 using the search terms “tooth AND (bleaching OR whitening),” I found 38 references. When I conducted similar searches for 1979 to 1988, 1989 to 1998, and 1999 to the present, I found 111, 456 and 225 references, respectively. Frazier and Haywood3 reported that 92 percent of dental schools now are teaching the custom tray bleaching technique. The safety and efficacy of this tooth-whitening method have been well-documented in clinical studies, and the ADA Seal of Acceptance has been awarded to tooth-whitening products.
Light augments tooth whitening with peroxide
MARY TAVARES, D.M.D., M.P.H., JACYN STULTZ, R.D.H., MARGARET NEWMAN, R.D.H., VALERIE SMITH, RALPH KENT, Sc.D., ELIZABETH CARPINO, B.A. and JO MAX GOODSON, D.D.S., Ph.D. JADA Continuing Education
The authors tested the adjunctive use of light with a 15 percent peroxide gel as a single-visit, in-office tooth whitening system.
Subjects (N = 87) with stained (> shade D4, Vita Zahnfabrik, Bad Säckingen, Germany) anterior teeth were randomly assigned to test (peroxide and light), peroxide control (peroxide gel) or light control (placebo gel and light) groups and were treated for one hour. The researchers evaluated tooth shade, color and subject response at baseline and post-treatment and at three and six months post treatment.
The initial shade unit reduction of combined light and peroxide treatment (8.4) was greatest compared with that of peroxide alone (5.9) and of light alone (4.9). Approximately 88 percent of these effects persisted for six months. Lightness was increased and yellowness decreased to a significantly greater extent in the test group than in either control. These findings were corroborated by subject evaluation. One week after treatment, moderate to greatly increased tooth sensitivity occurred in 20 percent of test subjects, 21.7 percent of peroxide control subjects and none of the light control subjects. Neither tooth sensitivity nor gingival redness was present at the three- and six-month visits.
Peroxide and light treatment significantly lightened the color of teeth to a greater extent than did peroxide or light alone, with a low and transient incidence of tooth sensitivity.
Light can increase the tooth-whitening effect of peroxide, thereby increasing the effectiveness of tooth-whitening procedures.
Effect of light energy on peroxide tooth bleaching
KAREN LUK, D.D.S., LAURA TAM, D.D.S., M.Sc. and MANFRED HUBERT, Ph.D. JADA Continuing Education
Light-activated bleaching is a method of tooth whitening. The authors conducted a study to compare the whitening effects and tooth temperature changes induced by various combinations of peroxide bleaches and light sources.
The authors randomly assigned 250 extracted human teeth halves into experimental groups (n = 10). A placebo gel (control), a 35 percent hydrogen peroxide or a 10 percent carbamide peroxide bleach was placed on the tooth surface and was irradiated with no light (control); a halogen curing light; an infrared, or IR, light; an argon laser; or a carbon dioxide, or CO2, laser. Color changes were evaluated immediately, one day and one week after treatment using a value-oriented shade guide and an electronic dental color analyzer. The outer enamel and inner dentin surface temperatures were monitored before and immediately after each 30-second application of light using a thermocouple thermometer.
Color and temperature changes were significantly affected by an interaction of the bleach and light variables. The application of lights significantly improved the whitening efficacy of some bleach materials, but it caused significant temperature increases in the outer and inner tooth surfaces. The IR and CO2 laser lights caused the highest tooth temperature increases.
Dentists performing an in-office bleaching technique with the use of an additional light source to accelerate tooth whitening should consider the specific bleaching agent being used, as well as the potential risks of heating teeth.
A specific combination of bleach and light that demonstrates good color change and little temperature rise should be selected for in-office tooth bleaching.
February 7, 2011
Spa-Dent is pleased to announce the release of the newest innovation in teeth whitening – The first combination Blue and Red LED Teeth Whitening Light.
Spa Dent has combined 450-470 nanometre blue and 620-630 nanometre red light to whiten teeth and heal the surrounding gum tissue. Blue LED light activation is the newest safest whitening technology which we have combined with Red LED light which is well documented for rapid wound healing.
Our recent introduction of our new proprietary extra strength gel that combines Carbamide Peroxide, Hydrogen Peroxide, Xylitol has exceeded expectations. The combination of the new light and the new gel formulation provides maximum whitening with virtually no sensitivity.
Please read the article below for additional information on red light therapy.
NASA SPACE TECHNOLOGY SHINES LIGHT ON HEALING
“So far, what we’ve seen in patients and what we’ve seen in laboratory cell cultures, all point to one conclusion,” said Dr. Harry Whelan, professor of pediatric neurology and director of hyperbaric medicine at the Medical College of Wisconsin. “The near-infrared light emitted by these LEDs seems to be perfect for increasing energy inside cells. This means whether you’re on Earth in a hospital, working in a submarine under the sea or on your way to Mars inside a spaceship, the LEDs boost energy to the cells and accelerate healing.”
Dr. Whelan’s NASA-funded research has already seen remarkable results using the light-emitting diodes to promote healing of painful mouth ulcers caused by cancer therapies such as radiation and chemotherapy. The treatment is quick and painless.
Data have also been received from Naval Special Warfare Command (Norfolk & San Diego) where 18-20 patients per day are being treated with NASA-LEDs and results indicate >40% improvement in musculoskeletal training injuries.
Data has also been received from the USS Salt Lake City (submarine SSN 716 on Pacific deployment) reporting 50% faster (7 day) healing of lacerations in crew members compared to untreated control healing (approximately 14 days).