Color Changes During Tooth Formation Clinical Trial
Official title:
Effect of Preoperative Use of an Anti-inflammatory on Tooth Sensitivity Caused by In-office Bleaching: A Randomized, Double-blind Clinical Trial
Perhaps the use of a more selective anti-inflammatory drug, capable of inhibiting enzyme specific for pain may be more effective in preventing the tooth sensitivity caused by the inflammatory response produced by in-office bleaching. To the extent of the authors´ knowledge, no study has so far addressed the use of a selective anti-inflammatory drug specific for pain enzyme on tooth sensitivity, being this the aim of the present investigation.
Study design This was a randomized, triple-blind, placebo-controlled, parallel-group clinical
trial, with an equal allocation rate to receive either one of two treatments. The study took
place in the clinic of the Brazilian Association of Dentistry in Guarapuava, Paraná from
August 2010 to December 2010.
Inclusion and exclusion criteria
Patients included in this clinical trial were at least 18 years old and had good general and
oral health. Participants were recruited by means of radio and TV advertisement. A total of
247 participants were examined in a dental chair to check whether they met the inclusion and
exclusion criteria. The participants were required to have six caries-free maxillary anterior
teeth, without resto- rations on the labial surfaces. The central incisors had to be shade C2
or darker as judged by comparison with a value- oriented shade guide (Vita Lumin, Vita
Zahnfabrik, Bad Säckingen, Germany). Participants who had undergone tooth-whitening
procedures, presented anterior restorations, were pregnant/lactating, had severe internal
tooth discoloration (tetracycline stains, fluorosis, and pulpless teeth), were taking any
type of medicine, had bruxism habits, or any other pathology that could cause sensitivity
(such as recession and dentin exposure) were excluded from the study, since they would not be
immediately eligible for a cosmetic treatment, such as bleaching. Participants who reported
some earlier or present health problems in the stomach, heart, kidney and liver, or
participants continuously using any with anti-inflammatory and antioxidant action were
excluded from the study. Sample size calculation The primary outcome of this study was the
absolute risk of TS. The absolute risk of TS was reported to be approximately 86 % for the
bleaching product Whiteness HP Maxx (FGM, Joinville, SC, Brazil). Thus, 30 patients were
required to have an 80 % chance of detecting, as significant at the two-sided 5 % level, a
de- crease in the primary outcome measure from 86 % in the control group to 41 % in the
experimental group.
Study intervention
Participants were randomly stratified by sex into the placebo and etoricoxib groups. The
randomization process was performed by computer-generated tables by a third person not
involved in the research protocol. Details of the allocated groups were recorded on cards
contained in sequentially numbered, opaque, sealed envelopes. These were prepared by a third
person not involved in any of the phases of the clinical trial. Once the participant was
eligible for the procedure, and completed all baseline assessments, the allocation assignment
was revealed by this envelope being opened by the mentioned third person. Neither the
participant nor the operator knew the group allocation, both being blinded to the protocol.
The participants from the placebo group received a placebo (Talco pharma SM-200-Henrifarma
produtos químicos e farmacêuticos LTDA, São Paulo, SP, Brazil) and participants from the
etoricoxib group received a dose of a selective COX- 2 inhibitor etoricoxib 60 mg (Arcoxia,
MSD, Campinas, SP, Brazil). All the participants were watched to ensure that they took the
drugs or placebo 1 h before treatment. The drugs were similar in appearance. A second dose of
placebo or etoricoxib (60 mg) was administered 24 h after the first dose. At the time the
participants were required to take the second dose of the medicine, the research auxiliary
called him/her and asked him/her to take the medicine. This procedure was implemented to
increase adherence to the protocol.
The gingival tissue of the teeth to be bleached was isolated using a light-polymerized resin
dam (Top Dam, FGM, Joinville, SC, Brazil). The 35 % hydrogen peroxide gel (Whiteness HP Maxx,
FGM) was used in three 15-min applications for both groups in accordance with the
manufacturer's directions. The in-office bleaching agent was refreshed every 15 min during
the 45-min application period. Two bleaching sessions with 1 week interval between them were
performed. All participants were instructed to brush their teeth regularly using fluoridated
toothpaste (Sorriso Fresh, Colgate- Palmolive, São Paulo, SP, Brazil).
Shade evaluation
Shade evaluation was recorded before and 30 days after the bleaching treatment using two
methods: subjective evaluation using a shade guide (Vita Lumin, Vita Zahnfabrik, Bad
Säckingen, Germany) and an objective evaluation using the spectrophotometer (Easyshade,
Vident, Brea, CA).
For the subjective examination, the 16 shade guide tabs were arranged from highest (B1) to
lowest (C4) value, so that the color C2 was set. Although this scale is not linear in the
truest sense, the changes were treated as though they represented a continuous and
approximately linear ranking for the purpose of analysis. The measurement area of interest
for shade matching was the middle one third of the facial surface of the anterior central
incisor. For calibration purposes, five patients who were not included in the sample because
they were used in the pilot study, participated in the training phase of this study. The two
examiners, blinded to the allocation assignment, scheduled these patients for bleaching and
evaluated their teeth against the shade guide at baseline and 30 days after the procedure.
The two examiners were required to have an agreement of at least 85 % (Kappa statistic)
before beginning the study evaluation. For the objective evaluation, a preliminary impression
of the maxillary arch was made using dense silicone Adsil (Vigodent S/A Indústria e
Comércio, Rio de Janeiro, RJ, Brazil). The impression was extended to the maxillary canine
and served as a standard color measurement guide for the spectrophotometer. A window was
created on the labial surface of the molded silicone guide for the central incisor to be
evaluated. The window was made using a metal device with well-formed borders, with a radius
of 3 mm. Only one operator took all the measurements in all 30 patients, using Vita Easyshade
(Easyshade, Vident, Brea, CA) before and 30 days after the bleaching therapy. The shade was
determined using the parameters of the Easyshade device where the following values were
indicated: L*, (a*), and (b*), in which L* represents the value from 0 (black) to 100 (white)
and a* and b* represent the shade, where a* is the measurement along the red-green axis and
b* is the measurement along the yellow-blue axis. The color comparison before and after
treatment is given by the difference between the two colors (ΔE), which is calculated using
the formula: ΔE=((ΔL*)2+(Δa*)2+(Δb*) 2)1/2.
TS evaluation
The patients recorded their perception of TS during the first and second bleaching sessions
using three pain scales. A 5-point verbal rating scale (0 = none, 1 = mild, 2 = moderate, 3 =
considerable, and 4 = severe], a 0 to 100 numerical rating scale and a visual analogue scale
using a 10-cm horizontal line with words "no pain" at one end and "worst pain" at the
opposite end were used in this study. Subjects were asked to record whether they experienced
TS during the treatment up to 1 h after, from 1 to 24 h and from 24 to 48 h after bleaching.
The worst scores/numerical values obtained in both bleaching sessions were considered for
statistical purposes. The values were arranged into two categories: percentage of patients
that reported TS at least once during treatment (absolute risk of TS) and overall TS
intensity.
Statistical analysis
The analysis was performed after the intention-to-treat protocol and involved all
participants who were randomly assigned. The statistician was blinded to the study groups.
The agreement between the examiners' objective evaluation was evaluated using the kappa
statistic. The primary outcome absolute risk of TS was compared by using the Fisher's exact
test at a 5 % level of significance. The relative risk as well as the confidence interval for
the effect size was calculated.
TS intensity (secondary outcome) was also statistical- ly analyzed. The mean/median and
standard deviation/interquartile range of the three pain scales were calculated. Color
change, another secondary endpoint, was used to assess the efficacy of the bleaching
treatment. For subjective evaluation, the means and standard deviations of SGU at baseline
and 30 days after bleaching for each group were calculated. In order to evaluate whether the
bleaching therapies were effective or not, the data from SGU of both groups were submitted to
a two-way repeated measures ANOVA. A post-hoc analysis (Tukey's test) was used to make
pairwise comparisons. The ΔL, Δa, Δb, and ΔE values were evaluated by Student's t test.
The data sets were plotted on histograms and inspected for normal distributions. Some data
did not appear to be normally distributed, and therefore, nonparametric statistical tests
were used to compare the various treatments. Statistical analyses of three pain scales
comparing the two groups at the three different assessment points were performed using the
Mann- Whitney U test. Comparisons between times within each group were performed using the
Friedman tests. In all statistical tests, the significance level was set at p = 0.05 values
less than or equal to 5 % indicated significant differences.
;
| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Completed |
NCT04407910 -
Office Bleaching Treatment by Using Rubber-cup and Air-powder Polishing Device Prophylaxis in Rondomised Clinical Design
|
Phase 4 |