A clinical study to evaluate the efficacy of a novel tray based tooth whitening system
Introduction
During the last decade there has been an increase in the availability of products that claim to have the ability to whiten teeth. Most of these products deliver their benefits either by increasing the efficiency of surface cleaning or by reducing the intrinsic or extrinsic stain by neutralising the colour using agents like hydrogen peroxide or carbamide peroxide. Measurement and further analysis of the effect of these whitening products using an appropriate parameter and technique would enable us to compare the efficacy of different products. There are a number of methods available for measuring the whitening effect, both instrumental and visual. The traditional visual assessment using shade guides is still one of the most common methods employed to assess tooth-colour changes.1 The commonly used instruments in dental research to measure tooth colour are colourimeter, spectrophotometer, spectroradiometer and digital camera.
The product related factors that influence the whitening efficacy of a bleaching system would be the type of bleaching agent (hydrogen peroxide, carbamide peroxide, etc.), concentration, frequency, duration of each application, period of treatment and accelerators.2 Two of the key factors in determining the overall tooth whitening efficacy from peroxide containing products are concentration and duration of application. Even though higher concentrations are more effective than lower, it can approach the efficacy of higher concentrations with extended treatment times.2 The optimum level of concentration and the overall treatment period has been researched for quite some time in dentistry. An in vitro study conducted by Sulieman et al.3 reported a higher ΔE value for 5% hydrogen peroxide applied 12 times compared to 35%, 25% and 10% applied 1, 2 and 7 times, respectively.
The mode of application of the product on the tooth surface also effects the treatment. Several delivery systems like strips, shields, trays and applicator brushes have been tested clinically to determine the most efficient and less time consuming method. A broad range of peroxide-based treatments are currently available including those that are professionally administered and dispensed (custom-tray-based systems), and self-directed (over-the-counter).4 Professional tray based bleaching systems are advantageous in that the bleaching is professionally carried out, this results in less gingival irritation and the patients have access to expert opinion regarding other local side effects such as sensitivity or mucosal irritation.
The present study investigates the efficacy of a tray based whitening system that uses a 6% hydrogen peroxide gel in terms of whiteness index and clinical shade guide scores. The primary objective of the study is to investigate the whitening efficacy of the bleaching system in 3 days. It was also designed to examine the whitening effect at 7 and 14 days.
Section snippets
Hypothesis
The null hypothesis of no difference between the whitening gel group and the no treatment group was tested against the hypothesis that whitening gel provided a significant improvement in tooth whiteness.
Materials and methods
A parallel, examiner blind, stratified two-group clinical study was carried out in the Department of Fixed and Removable Prosthodontics, Leeds Dental Institute, United Kingdom in June 2006. The study protocol and informed consent were reviewed and accepted by Leeds (East) Research Ethics Committee. The study population comprised of healthy adult volunteers who consented to have their teeth whitened. Candidates who expressed their interest in participating in the study were invited to the
Results
Forty-nine subjects completed the study, with 25 in the test group and 24 in the control group. One subject failed to attend the 7-day visit from the control group due to ill-health and was withdrawn from the study. Data for colour analysis and comparisons were available for all the subjects who completed the study.
Mean and standard deviations of the clinical scores, colour parameters (L*, a* and b*) and whiteness index were calculated for each time period (Table 1) and an Independent Sample t
Discussion
There are significant numbers of tooth whitening products that are available in the market. It is not only whitening efficacy but also factors such as the duration of treatment, time period of application, mode of application, longevity of the whitening effect that influence the popularity of the product amongst consumers.9 Bleaching teeth under dental supervision has been emphasised by different investigators due to the fact that it offers patients the option of different products and, most
Conclusion
The clinical trial showed a significant and meaningful improvement in the whiteness index (WIO) for the test product over the study period from 3 days both for the clinical and digital data. WIO is a suitable whiteness index which could be used to measure the whitening changes to discriminate between products in clinical trials. The Imaging system is stable and robust and could be employed in the measurement and comparability of the whitening effects of different treatments.
References (14)
- et al.
A comparison of new and conventional methods for quantification of tooth color
Journal of Prosthetic Dentistry
(1990) The bleaching of teeth: a review of the literature
Journal of Dentistry
(2006)- et al.
The effect of hydrogen peroxide concentration on the outcome of tooth whitening: an in vitro study
Journal of Dentistry
(2004) - et al.
Comparison of the ability of different colour indices to assess changes in tooth whiteness
Journal of Dentistry
(2007) - et al.
Clinical evaluation of a novel whitening gel, containing 6% hydrogen peroxide and a standard fluoride toothpaste
Journal of Dentistry
(2004) - et al.
Quantitation of vital bleaching by computer analysis of photographic images
Journal of the American Dental Association
(1999) - et al.
Vital bleaching with whitening strips: summary of clinical research on effectiveness and tolerability
Journal of Contemporary Dental Practice
(2001)
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A novel model to predict tooth bleaching efficacy using autofluorescence of the tooth
2022, Journal of DentistryCitation Excerpt :For white-light images, two linear polarization filters were placed in front of the camera to reduce the occurrence of specular reflection due to a high light source. This method has been widely used in digital white image studies, especially in studies investigating the effects of tooth bleaching procedures [21–23]. Images of the buccal and cross-sectioned surfaces were taken before and after tooth bleaching.
Quantitative light-induced fluorescence as a potential tool for detection of enamel chemical composition
2020, Photodiagnosis and Photodynamic TherapyTooth colour and whiteness: A review
2017, Journal of DentistryCitation Excerpt :In a study of colorimetric analysis of shade guides, it was demonstrated that the WIO gave the best fit with the instrumental colour measurements [57]. This index has been used in a number of tooth whitening studies in vitro and in vivo, including tooth bleaching studies with hydrogen peroxide products [56,57] and whitening studies with toothpastes containing blue optical whitening technologies [58,59]. The proposed WID showed an improved correlation to the associated visual perception data than all the other CIELAB and whiteness/yellowness indices tested in the study under laboratory and clinical conditions, only WIO was comparable to WID [60].
In vitro and clinical evaluation of optical tooth whitening toothpastes
2017, Journal of DentistryCitation Excerpt :The non-contact digital camera based system used in the clinical study has been shown to be a reproducible and reliable means of measuring tooth colour and tooth whiteness [18]. This type of instrumental analysis of tooth colour helps to eliminate the introduction of bias within studies [21], can objectively measure small colour differences and the approach has been used successfully within a number of tooth whitening studies [14,16,22–25]. For example, a meta-analysis of tooth whitening studies in a 4-year period confirmed the reliability of digital image analysis techniques for tooth whitening studies [24].
Development of polarization dental imaging modality and evaluation of its clinical feasibility
2012, Journal of DentistryCitation Excerpt :As an alternative, WIO has been considered as a useful method for quantitatively estimating tooth whiteness before and after treatment.14,19 A previous study20 showed that the WIO of 24 tooth samples increased from −73.68 to −49.79 (a 32.4% increase) after 14 days of tooth whitening treatment. Although it is not valid to directly compare the previous study20 with this study because of differences in experiment methods, WIO also increased by 22.3% in the cervical 1/3rd, 26.4% in the middle 1/3rd, and 34.5% in the incisal 1/3rd after tooth whitening treatment (Fig. 7), indicating that the teeth became brighter after treatment.
Colorimetric evaluation of tooth colour
2010, Colour Measurement: Principles, Advances and Industrial Applications