In-office Bleaching Using a Violet Light

The objective of this clinical study is to evaluate the effect of the whitening treatment performed with the violet LED light (405-410 nm), with or without a bleaching gel, on the tooth color changes (immediate and long-term), tooth sensitivity, satisfaction of participants in relation to the technique and impact on their quality of life.

This study was approved by the research ethics committee of School of Dentistry of University of Sao Paulo (Protocol# 1.981.756). The experimental design is in according to CONSORT. The present research will be a blind, parallel and randomized study with similar allocation between the treatment groups. It will be included 200 participants, selected among the patients of the Special Laboratory of lasers in dentistry (LELO-FOUSP). After being being informed of the objectives of the study the participants will be randomly divided into a treatment group (n = 25):

G1 - In-office bleaching performed with 35% hydrogen peroxide (4 sessions, 1 session/week).

G2 - In-office bleaching performed with 30% carbamide peroxide (4 sessions, 1 session/week).

G3 - In-office bleaching performed with Violet LED (405-410 nm, 4 sessions, 1 session/week).

G4 - In-office bleaching performed with Violet LED (405-410 nm, 4 sessions, 2 sessions/week).

G5 - In-office bleaching performed Violet LED associated to 35% hydrogen peroxide (4 sessions, 1 session / week).

G6 - In-office bleaching performed Violet LED associated to 30% carbamide peroxide (4 sessions, 1 session / week).

G7 - hybrid technique HP (Violet LED + application of 35% hydrogen peroxide + violet LED) (4 sessions, 1 session/week).

G8 - Hybrid technique CP HP (Violet LED + application of 30% carbamide peroxide + violet LED) (4 sessions, 1 session/week).

The primary outcome of this study is the color alteration, which will be evaluated quantitatively by colorimetric (subjective) and spectrophotometric (objective) tests. Additionally, will be evaluated dental sensitivity during and after treatment (predetermined times), patient satisfaction regarding the treatment, and impact on patient quality of life (questionnaire OHIP-14).

The color measurement will be blind, in predetermined times (before the treatment, immediately after the treatment, 14 days after, 3 months after, 6 months after and 12 months after). It will be performed by two methods: subjectively, with a color scale; and objectively, with a clinical spectrophotometer.

The evaluation of dental sensitivity will be measured with a Visual analogue scale (VAS). It will be performed immediately after the treatment and 48 hours after the treatment.

The patient satisfaction regarding the treatment will be measured with a questionnaire for self-evaluation of the treatment, and will be applied 14 days after the end of treatment, 3 months after, 6 months after and 12 months after.

The evaluation of quality of life of the patients will be performed with the OHIP-14 questionnaire, which will be applied after the end of the treatment.

Inclusion criteria

• Presence of all the teeth, without restorations or caries on anterior teeth.
• Patients presenting the canine tooth color A3 (according to Vita classical scale) or darker.

Exclusion criteria

• Patients presenting systemic pathologies
• Patients presenting periodontal diseases
• Smokers or patients with systematic use of alcohol
• Patients presenting teeth with color alterations by tetracycline, fluorosis, endodontic treatments.
• Patients with historic of self-referenced sensitivity
• Pregnant or Breastfeeding period patients
• Presence of restorations on anterior teeth
• Patients presenting bruxism or systematic use of analgesics or anti-inflammatory drugs