In-office Vital Bleaching with Adjunct Light Dr. Ahmed AlMokhadub.

In-office Vital Bleaching withAdjunct Light

Dr. Ahmed AlMokhadub

“There is no higher glory for one who professes the healing art [of dentistry] than of preserving the natural tissues.” E.P. Wright

Vital bleaching was introduced to the profession in 1989, using 10% carbamide peroxide in a custom bleaching tray for at-home use.

Light-assisted, in-office bleaching methods use higher concentrations of peroxide in conjunction with supplemental light to enhance the effect of tooth whitening. These methods tend to appeal to patients who have a desire for rapid results and perhaps those not interested in wearing custom trays at night or those not successful with over-the-counter products

Introduction

Examination

A through clinical examination should reveal not only cases that are suitable for inoffice bleaching with adjunct light, such as teeth with mild to moderate discoloration, but also teeth that are not suitable using this method, such as patient who presents with severe intrinsic staining

Greater tooth sensitivity has been reported with in-office bleaching with adjunct light compared with no light

Risk factors for sensitivity:

existing decay

Gingival recession

cervical abrasions

history of sensitivity

This finding means that additional doses of ibuprofen may be necessary after the in-office bleaching procedure to prevent postoperative sensitivity. Applying 4% to 6% potassium nitrate gel on the lingual surface of the teeth during the appointment is another strategy to minimize tooth sensitivity.

Patients can also be provided with 600 mg of ibuprofen 30 minutes before the in-office procedure to help reduce sensitivity. However, a recent study showed that patients who received ibuprofen 30 minutes before an appointment compared with patients who received a placebo capsule reported the same level of sensitivity 1 hour after the in-office procedure, which continued up to 24 hours.

Patient identified with existing tooth sensitivity may prebrush for about 2 weeks with a toothpaste containing potassium nitrate to help minimize sensitivity

Concentrations of hydrogen peroxide between 15% and 40% are used for professional in-office bleaching, which poses a risk of chemical tissue damage. Also the human eyes and oral soft tissue should be protected from the blue light or ultraviolet (UV) radiation emitted from the bleaching light. A recent study reported the health risk from optical radiation of 7 commercially available bleaching lamps.

SETTING EXPECTATIONS OF TREATMENT TIME

The primary advantage that attracted patients to in-office bleaching is the expectation of rapid results.

The question of how much time is saved with in-office techniques is not easy to answer, because results can vary among patients and depend on the cause of the stains, but some general expectation should be discussed based on available clinicalevidence

Seven days of at-home bleaching with 10% carbamide has been shownto be equivalent to 3 times of 15-minute applications of 38% hydrogen peroxide or 5 days of at-home bleach and 1 hour’s treatment with 28% hydrogen peroxide with supplemental light.

A combination technique of in-office bleaching plus home bleaching has been shown to be more effective than in-office bleaching alone

Bernardon and colleagues compared the clinical efficacy of home bleaching, in-office bleaching (with and without light), and a combination technique of in-office bleaching plus home bleaching

Color measurements after the first week showed better bleaching results with in-office bleaching with light or the combination technique compared with the at-home bleaching alone.

After 2 weeks, there was no significant difference among the 3 techniques.

Whitening with supplemental lighting is a controversial topic in dentistry not limited to safety-related issues in nondental settings but also because of the conflicting reports published in the existing dental literature. Various types of lasers (argon, CO2, diode, potassium titanyl phosphate) have been investigated in vitro; some report improved bleaching results, whereas others report no significant effect.

A common concern with the use of lasers for bleaching is the potential dangers associated with increased pulpal temperature.

POTENTIAL SOURCES OF VARIABILITY ASSOCIATED WITH BLEACHING LIGHT STUDIES

Color-measuring Instruments

visual method

Colorimeters

Spectrophotometers

imaging systems such as digital cameras

Variability Associated with Different Light Sources

high-intensity discharge (HID) lamps (metal halide, xenon arc, plasma arc)

light-emitting diode (LED) lamp

The use of light as a means of decomposing a chemical compound is known as photolysis.

It was commonly accepted that heat was responsible for the dissociation of hydrogen peroxide

An in vitro bleaching study was conducted in which a xenon arc lamp was compared with a diode laser near IR (960 nm); the study showed that the diode laser produced an unsafe temperature increase up to 12C beyond the critical threshold

Sulieman and colleagues using a plasma arc lamp, xenon-halogen lamp, halogen lamp, and a diode laser, found the only lamp to produce pulpal temperatures beyond the critical threshold was the diode laser near IR (830 nm).

Photolysis of hydrogen peroxide can occur by light of wavelengths of 365 nm or less

Also, any light with a spectrum in the UV-B range (280–315 nm) is notacceptable for intraoral use. Many of the HID lamps used in dentistry have a spectral emission primarily in the visible spectrum (400–700 nm) and some portions of the UV-A spectrum (315–400 nm).

Carotenoids, absorbed primarily at wavelengths of 400 to 500 nm, have been used as a bleaching agent activator that also serves as a colorant, giving the otherwise colorless hydrogen peroxide a red-orange color. If the bleaching agent absorbs the light energy of any frequency, it heats and thus decomposes.