Efficacy evaluation of toothpaste - Part 4: Guidelines for efficacy evaluation on dentin hypersensitivity
1 Scope
This part of WS/T 326 specifies the classification, evaluation and clinical test requirements for efficacy evaluation on dentin hypersensitivity of toothpaste products.
This part is applicable to toothpaste products that are declared to have an efficacy on dentin hypersensitivity, and of which the physical and chemical properties, hygiene and safety indexes meet the corresponding national standards.
2 Normative references
The following referenced documents are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
WS/T 326.1 Efficacy evaluation of toothpaste - Part 1: General principles
3 Terms and definitions
For the purposes of this document, the terms and definitions given in WS/T 326 Part 1 apply.
4 Efficacy evaluation
4.1 The clinical tests in different time periods are conducted according to the requirements of this part based on the classification of products with an efficacy on dentin hypersensitivity, and the efficacy evaluation is conducted through statistical analysis according to the change of average hypersensitivity before and after use of test products (test group) and control products (control group).
4.2 The average dentin hypersensitivity indexes of test group shall be significantly reduced in test period, which is statistically significant compared with the negative control group, and once any average dentin hypersensitivity index reduces by 15% or above, it may be considered that the test group has an efficacy on dentin hypersensitivity.
5 Clinical test requirements
5.1 Principle of test design
Randomized, blind, parallel or crossover test design shall be adopted in the clinical test. After the baseline examination, the subjects shall be distributed in a balanced way, including their gender, age and number of teeth.
The test design may be subjected to the comparison of the toothpaste of test group and that of negative control group or placebo control to verify the test product is superior to the toothpaste of the negative control group or placebo control.
5.2 Test period
The test period starts from the time when the efficacy of test product displays and lasts for more than 4 weeks. The test period of toothpaste products that are declared to have an efficacy on dentin hypersensitivity shall be determined according to their characteristics. The hypersensitivity conditions shall be checked and recorded at baseline, mid-term test and end of test respectively.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Efficacy evaluation
5 Clinical test requirements
