Medicaments Substances in Therapeutic Use Clinical Trial
Official title:
Potassium Nitrate Influence on Post in Office Bleaching Sensitivity: a Triple Blinded Randomized Clinical Trial
This study will determine the effectiveness of the use of desensitivity gels prior in office
bleaching on risk and intensity of tooth sensitivity caused by in-office bleaching using 35%
hydrogen peroxide and using different types of potassium nitrate. Materials and Methods:
Seventy five patients will be selected for this triple-blind, randomized, cross-over,
placebo-controlled clinical trial. 10 minutes prior to bleaching procedure, patients will
receive the the potassium nitrate 2% or placebo gel application on vestibular surface and
Toothpaste 15 days before start the bleaching procedure (group 1: placebo gel + Colgate
toothpaste; Group 2: Placebo gel + Nitrate toothpaste Sensodyne and Group 3: Potassium
Nitrate + Colgate toothpaste). The whitening treatment with 35% hydrogen peroxide will be
carried out in two sessions with a 7-day interval.
Tooth sensitivity will be assessed before, during and 24 hours after the procedure using
analog visual and verbal scales. Color alteration will be assessed by a Vita Guide scale at
the end of the last session. Relative risk to sensitivity will be calculated and adjusted by
session; while comparison of overall risk will performed by McNemar's test. Data on the
sensitivity level and color shade will be subjected to the Friedman, Wilcoxon (α = 0.05). If
necessary, multiple comparation will be done using Tukey's test.
This study will be a randomized, triple-blinded, placebo-controlled clinical trial, and split
mouth study design.
The patients included will be submitted to two in-office bleaching sessions receiving the
potassium nitrate 5% or placebo gel (prior the bleaching session, for 10 minutes), associated
to normal toothpaste or potassium nitrate containing toothpaste (15 days prior and during the
bleaching procedure).
A delay of 1 week between the sessions will be established.
Participants:
Patients included in this clinical trial will be between 18 and 29 years old with good oral
health, all anterior tooth healthy and to agree with TCLE (Term of Free and Informed
Consent). Only patients presenting all six upper anterior teeth with shade mismatching with
2.5 M2 (VitaClassicalscale, Vita-Zahnfabrik, Bad Sackingen, Germany).
Patients with any of the six upper anterior teeth with caries, restoration, severe
discoloration (e.g., stains caused by tetracycline), enamel hypoplasia, gingival recession,
dentin exposure, pulpitis, or endodontics will be excluded. Participants submitted to
previous bleaching procedures, presenting prior tooth sensitivity, known allergy to any
component of medication used in the study, pregnant or breastfeeding, lack the tretament will
be also excluded.
Sample Size Calculation:
The sample calculation will be based on the primary binary outcome (sensitivity risk 24 hours
after the procedure) for superiority trial. Power of the test will be set at 80%, considering
a type I error of 0.05; risk to tooth sensitivity for control and experimental group of 25,2%
with reduction of 60%. The calculation resulted in 75 patients.
Randomization:
A randomized list will be computer-generated by a person not involved in intervention or
evaluation. The participants were defined as blocks in the randomization process, where the
sequence of treatment (placebo or etodolac) will be randomly set for each block by using
computer-generated tables (www.sealedenvelope.com). The sequence will be inserted into sealed
envelopes numbered from 1 to 75 that were opened by the operator only at the moment of the
intervention. The patients were numbered according to the sequence of enrollment. Neither the
participant nor the operator will know the group allocation determining blinding to the
protocol.
Baseline evaluation:
Prior to bleaching procedure, the teeth will be cleaned using rubber cups associated to
pumice and water. The shades of six upper anterior teeth will be assessed on a baseline using
the Vita classical guide scale.
Intervention:
Prior to each bleaching session, the patients will receive the potassium nitrate 2% or
placebo Gel for 10 minutes. Also, Normal and potassium nitrate toothpaste will be used before
and during the bleaching tretament, as follows: group 1: placebo gel + Colgate toothpaste;
Group 2: Placebo gel + Nitrate toothpaste Sensodyne and Group 3: Potassium Nitrate + Colgate
toothpaste.
Neither the operators responsible for intervention and evaluation nor the patients knew the
content which treatment will be done.
A light-cured resin dam will be applied on the gingival tissue corresponding to the teeth to
be bleached.
A 35% hydrogen peroxide based bleaching agent (DFL) will be mixed and applied on the
vestibular surface of teeth, remaining for 40 minutes. After this time, the bleaching agent
will be removed. A second session will be carried out after 1 week following the same
procedures.
Evaluations:
The tooth sensitivity reported by patients will be assessed using a visual analog scale (VAS)
and verbal rating scale (VRS). The VAS consisted of a scale 10 cm in length ranging from
green (absence of pain) to red (unsupportable pain). The patient set his or her level of
sensitivity by pointing to the color corresponding to this level, while the distance from
this point to the green border will be recorded. For VRS, the patient reported his or her
level of sensitivity based on scores: 0 = none, 1 = light, 2 = moderate, 3 = considerable and
4 = severe. The tooth sensitivity will be assessed during the bleaching, immediately after
bleaching agent removal and after 24 hours. For this last assessment, only the VRS will be
used. Tooth sensitivity will be measure: baseline, at 40 minutes during the bleaching
procedure, after the bleaching procedure and 24 hours after. One week after each session the
tooth color will be evaluated again using the same procedure described previously.
;
| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Completed |
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|
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| Completed |
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Phase 4 | |
| Completed |
NCT03065673 -
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|
N/A |