Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT02605239 |
| Other study ID # |
2013-18a |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
November 11, 2015 |
| Last updated |
November 12, 2015 |
| Start date |
March 2013 |
| Est. completion date |
October 2015 |
Study information
| Verified date |
November 2015 |
| Source |
University of Chile |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
Chile: Comité de Ética Científico |
| Study type |
Interventional
|
Clinical Trial Summary
58 patients between 18 and 76 years who attended the Operative Dentistry Clinic at Dental
School, Universidad de Chile, were included in the study. Those patients were bleaching and
included in this study and signed a consent form. The patients were treated with 10%
carbamide peroxide (CP) gel (Whiteness Perfect, FGM) to each subject with verbal
instructions for 3 weeks with daily applications of 1 hour according to manufacturers
indications , before and after this procedure was applied again the OHIP-Esthetics , PIDAQ
and OES questionnaire form, had 30 minutes to answer it, were completed before , immediately
after and one month control post-bleaching procedure.
Description:
This study was approved by the Ethics Committee of the Faculty of Dentistry (13/18a). This
study included 58 patients aged between 18 and 76 years who attended the Operative Dentistry
Clinic at the Dental School from the Local University and were eligible for bleaching (see
eligibility criteria in the next item). Dental bleaching, free of charge, was suggested to
the patients as a way to improve the patient's smile. The patients were informed about the
benefits and possible side effects of the procedure in a standardized manner.
Eligibility criteria for dental bleaching Participants were evaluated in a dental chair and
after prophylactic dental treatment with pumice and water. To be eligible for dental
bleaching, participants should have good general and oral health. Each subject should have
at least one central incisor shaded A2 or darker, assessed by comparison with a
value-oriented shade guide (Vita classical; Vita Zahnfabrik, Bad Säckingen, Germany).
Patients who had undergone previous dental bleaching procedures, under orthodontic
treatment, who were pregnant or lactating, or who had bruxism habits were not eligible for
dental bleaching. Participants with restorations on the labial surfaces of their anterior
teeth, non-carious cervical lesions, veneers, full crowns, gingival recession, spontaneous
tooth pain, internal tooth discoloration, and teeth with endodontic treatment or fluorosis
were also not included as they could not be immediately eligible for dental bleaching.
Bleaching Procedure For the participants who were bleaching procedure, we made alginate
impressions of each subject's maxillary and mandibular arches, and these were filled with
dental stone. We did not apply block-out material to the labial surfaces. A 1-mm soft vinyl
material, provided by the manufacturer (FGM Dental Products, Joinville, SC, Brazil) was used
to fabricate the custom-fitted tray to hold the bleaching gel. The bleaching tray was
trimmed 1 mm beyond the marginal gingiva and we delivered a 10% carbamide peroxide (CP) gel
(Whiteness Perfect, FGM) to each participant. We give them verbal instructions to apply the
product 1 hour daily for 3 weeks. After each application, the patient should remove the
tray, wash it with water, and brush teeth as usual. Verbal instructions for oral hygiene
were also given, encouraging regular brushing with fluoridated toothpastes that did not
contain whitening components.
For these participants, the OHIP-Esthetics, PIDAQ and OES surveys were applied before , one
week and one month after the end of the bleaching procedure, and the patient was also given
30 minutes to complete it.
Color Evaluation Color evaluations were performed using subjective and objective methods.
For the subjective evaluation, the 16 tabs of the Vita shade Classical guide Vita classical
(Vita Zahnfabrik, Bad Säckingen, Germany) were arranged from highest (B1) to lowest (C4)
value and used to determine tooth color. Although this scale is not linear in the truest
sense, it was treated as continuous with a linear ranking. Two calibrated evaluators with an
agreement of at least 85% (using weighted kappa statistics) recorded the shade of the middle
area of the labial surface of the upper central right incisor according to the American
Dental Association guidelines. Color was registered at baseline and during treatment (after
the first, second, and third week of bleaching), and one week and one month after the end of
the bleaching protocol to corroborate the effectiveness of bleaching procedure. The color
change between baseline and each recall time was calculated as the change in the number of
shade guide units (ΔSGU), which occurred toward the lightest end of the value-oriented list
of shade tabs. In case the operators disagreed on the color, a consensus was reached before
dismissing the patient.
In the objective evaluation, a digital spectrophotometer (Vita Easyshade, Vita Zahnfabrik)
with a reliability of 97% was used. An impression of the maxillary arch was taken with dense
silicone paste (Coltoflax and Perfil Cub, Vigodent, Rio de Janeiro, Brazil) and a window was
created on the labial surface of the silicone guide using a metal device with a radius of 6
mm to allow adaptation of the tip of the spectrophotometer device and to standardize the
spectrophotometric color evaluation across all recall periods.
The color coordinates (L*, a*, and b*) were recorded. The value for L* represented the value
from 0 (black) to 100 (white), and a* and b* represented color along the red-green axis and
yellow-blue axis, respectively. The difference between baseline and each recall period (∆E)
was calculated using the formula (CIE, 1978) ∆E = [(∆L*)2+(∆a*)2+(∆b*)2]1/2.
Tooth Sensitivity Evaluation Patients were asked to keep a daily record of whether they
experienced tooth sensitivity (TS). The participants were instructed to indicate their daily
pain using a visual analog scale (VAS).3, 6, 7 This scale is a 10-cm horizontal line labeled
no tooth sensitivity at one end and unbearable tooth sensitivity at the other end. The
patient should mark with a vertical line across the horizontal line of the scale the
intensity of the tooth sensitivity. Then, the distance in mm from the zero end was measured
with the aid of a millimeter ruler.
Oral Health Impact Profile (OHIP-Esthetics) questionnaire Satisfaction was measured using
the OHIP-Esthetics questionnaire validated in Chilean Spanish .The questionnaire was
administered by a research operator at baseline, at one week, one month and nine months
(before prophylaxis) after bleaching. Each statement was accompanied by a Likert-type scale,
which generated a score ranging from 4 to 0 (very often = 4, fairly often = 3, occasionally
= 2, hardly never = 1, never = 0). These individual scores were added together to give a
summary score ranging from 0 (minimum) to 56 (maximum). The outcomes were considered the sum
of the OHIP-Esthetics and dimension scores. The internal consistency was evaluated using
Cronbach's Alpha test.
The Psychosocial Impact of Dental Esthetics Questionnaire (PIDAQ) questionnaire The
questionnaire consisted of 23 items grouped into four components using factor analysis: 1)
dental self-confidence ; 2) social impact ; 3) psychosocial impact ; and 4) esthetic concern
.9 The first factor, dental self-confidence, consisted of six items from the self-confidence
scale. The second factor, social impact, contained eight items from the social aspects scale
of the quality of life questionnaire. The third factor, psychosocial impact, was derived
from six formulated items relating mainly to the psychosocial impact of dental esthetics.
The fourth factor was the esthetics. The patient was asked to evaluate the items using a
five-point Likert scale with numerical values 0 = "not at all", 1 = "a little", 2 =
"somewhat", 3 = "strongly" and 4 = "very strongly". The questionnaire was administered by a
research operator at baseline, one week, one month, and nine months (before prophylaxis)
after bleaching and was validated in Spanish with a confidence reported by Cronbach´s alpha
of 0.90.10 The outcomes were considered the sum of the PIDAQ questionnaire and factor
scores; the internal consistency was evaluated using the Cronbach's Alpha test.
Orofacial Esthetic Scale (OES) The Orofacial Esthetic Scale was originally developed in the
Swedish language, the OES-S. For international use, the OES-S was translated into
English,resulting in the OES-E . The OES consists of eight questions, assessing the
appearance of the face, profile, mouth, tooth alignment, tooth shape, tooth colour and gums,
as well as an overall impression of oro-facial aesthetics. Answers to the eight questions
are scored on 11-point numeric rating scales, ranging from 'Very dissatisfied' (score 0) to
'Very satisfied' (score 10). The scores of the first seven items are added to a summary
score. Therefore, the OES summary score ranges from 0 (worst score -patient is very
dissatisfied with all aesthetics items) up to 70 (best score - patient is very satisfied
with all aesthetics items). The score of the eighth item (overall impression score) is
judged separately, thus ranging from 0 (worst score - patient is very dissatisfied on global
assessment) up to 10 (best score - patient is very satisfied on global assessment). Hence,
lower scores imply more impaired self-perceived oro-facial aesthetics.
Sample size calculation Based on previous study we considered a difference of 4 units in any
of the domains to be clinically important. With a significance level of 5% and a power of
90%, a minimum sample size of 58 participants per group would be required to detect a
difference of 4 units in one of the domains of the questionnaires on before and after
comparisons.
Data collection and statistical analysis Data from the OHIP-Esthetics PIDAQ and OES were
collected on a spreadsheet and analyzed by a psychologist that was blind to the group
assignment.
Normality of the data bleaching and the homogeneity of the variance-covariance matrix were
evaluated with the Kolmogórov-Smirnov test. As data was not normally distributed, treatment
efficacy (ΔE and ΔSGU) was evaluated with respect to color change using the Wilcoxon Signed
Rank test.
The mean intensity of tooth sensitivity in VAS scale was reported as mean and standard
deviations. The percentage of patients who experienced tooth sensitivity at least once
during the bleaching therapy was considered the absolute risk of tooth sensitivity, reported
as percentage with the 95% confidence interval.
All statistical analyses were performed using SPSS 22.0 (SPSS Inc., Chicago, IL, USA) at a
level of significance of 5% (α = 0.05).
