Tooth whitening product laboratory studies and anti-stain or stain removal performance or efficacy testing of teeth whitening toothpaste, stain-prevention mouthwashes, whitening strips, varnishes, gels or other dentifrices supporting product development and claim substantiation

Assessment of tooth whitening, anti-stain or stain removal efficacy of novel oral care products such as tooth whitening toothpastes, stain control mouthwashes or whitening strips can accelerate product development. Whether your are developing products for home-use or professional teeth whitening treatments, consumers are demanding continual innovation in tooth whitening products and to meet their expectations of novel products and differentiate your brand in a crowded marketplace, you need to be able to demonstrate product performance or efficacy through robust quantification of tooth stain prevention, stain removal or whitening. This data is often used in the generation of marketing claims or for claim substantiation or to guide further formulation development.

In vivo, clinical studies can be expensive to commission, with costs associated with screening and compensation of large numbers of suitable volunteers as well as the training of clinical and operations staff and running costs of clinical study sites and dental surgery facilities. Volunteers are subjected to moderately invasive dental procedures and may be requested to follow restrictions in terms of diet and dentifrice use over as many as 6 months which is a long time for a volunteer to remain compliant. Inevitably, some volunteers will withdraw from the study and this must be factored in when deciding how many volunteers to enroll in the study.

Instead, a well-designed in vitro laboratory test can often yield the required data much more quickly and at a lower cost. Such studies, whether they are to support early-stage development of a product formulation or in support of marketing claims or pack claims, can be routinely carried out in our laboratory giving you the insight you need to differentiate your brand and products.

In Vitro Laboratory Studies for Anti-Stain, Stain Removal or Tooth Whitening

Our dedicated team of oral care scientists conduct robust in vitro studies using relevant models for anti-stain, stain removal, and whitening testing. We are particularly adept at designing bespoke testing for your whitening toothpaste, stain control mouthwash or whitening strip products and your specific testing needs combining visual, instrumental and photographic assessments enabling our customers to power ahead safely.

A typical anti-stain study would measure in vitro stain build-up on bovine enamel specimens following multiple exposure to test product, saliva and a specially formulated staining solution containing a mixture of tea, coffee, red wine and tobacco extract.  Relevant controls or benchmark products would be included and the test would be appropriately powered to reveal any significant product differences. Stain can be assessed subjectively by trained assessors or instrumentally using a chromameter that measures lightness and hue (L*a*b*). 

A typical stain removal study would involve staining bovine teeth or enamel specimens with a stain derived from e.g. tea and coffee and then measuring the amount of stain removal following one of several product applications.  In the case of toothpastes this could be performed using a mechanical brushing machine. We are also able to provide Pellicle Cleaning Ratio (PCR) testing whereby the abrasivity of toothpastes can be quantified against a calcium pyrophosphate standard. The degree of staining is assessed before and after treatment using a chromameter that measures L*a*b* colour parameters.  

Whitening strips or peroxide-containing gels/varnishes that remove intrinsic tooth stain can be evaluated using extracted human teeth.  Results from our studies are provided to the client in fully-signed off reports containing data tables, graphs, discussion and conclusions.

For over 20 years our Clinical Research Services group has been a trusted partner for developers and manufacturers of oral care products. We provide a one source solution for both whitening, anti-stain and stain-control studies as part of our wider in vitro oral care product laboratory testing, providing robust data to support the efficacy of novel treatments with whitening capabilities, such as toothpaste, mouthwashes, varnishes, chewing gum and bleaching kits. Other functional claims areas that we support include X-shades whiter, restores natural tooth brightness, chemical stain preventions, extrinsic stain removal, stain prevention, propensity to stain and enamel gloss.

Whitening products are formulated to include active ingredients that whiten teeth by different modes of action. One example is abrasives (such as silica), which mechanically remove extrinsic stains when moved across the surface of a tooth. Another ingredient category is bleaches (such as peroxide), which lighten intrinsic and extrinsic stain by altering the structure of chromogens. In addition, many whitening oral care products are formulated to include active ingredients that help maintain a whiter tooth shade by preventing stains from building up in the pellicle layer (a layer of naturally occurring proteins that forms over the surface of enamel) and in the porous surfaces of enamel. Biosurfactants (such as sodium lauryl sulphate), are one such example which alter surface properties and prevent stains from adhering to the pellicle layer and the enamel surfaces. 

Our scientists can design bespoke in vitro test models to support your formulation studies or support the development of a new ingredient. Robust, science-led comparative studies can drive insight to help inform formulation development, enable your decision making, and accelerate your development process.


Intertek Clinical Research Services (CRS) has a dedicated in vitro laboratory which conducts testing of all aspects of Oral Care products. We are particularly adept in designing bespoke in vitro models to cater for your specific requirements. Intertek Clinical Research Services is licensed to handle and store human tissue under the Human Tissue Act 2004 and follows the principles outlined within the act as well as complying with local ethical guidelines.

In Vitro Oral Care Product Services

Elm House, Unit A4
Oaklands Office Park
Hooton Road, Hooton
Cheshire, CH66 7NZ
United Kingdom

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