Knowledge of Hong Kong adults on tooth whitening and related legal regulations

Abstract

Aim: This community health project aimed to investigate the knowledge of Hong Kong adults on tooth whitening and the recent changes in the legislation. Methods: The target population was adults 18 to 54 years old who had resided in Hong Kong for more than 6 months and were capable of communicating in Chinese or English. Using a combination of purposive and quota sampling method, pedestrians in busy locations in five selected districts throughout Hong Kong were approached. Information was collected through face-to-face interviews with the use of a structured questionnaire. Participants' knowledge of tooth whitening was assessed by asking whether they agreed or disagreed with each of six selected statements. A knowledge score was calculated by counting the number of correct answers. Results: A total of 341 adults participated in the survey. Among them, 194 (57%) were women while 147 (43%) were men. Regarding their age distribution, 23%, 23%, 22% and 32% were in the 18-24, 25-34, 35-44 and 45-54 age group, respectively. Around two thirds of the respondents were dissatisfied with their current tooth colour, with a higher percentage among the women than the men (68% vs 55%, p=0.019). Two thirds (66%) of the participants had never tried tooth whitening before and among them, 62% would like to try. The mean tooth whitening knowledge score of the participants was 1.8 (SD=1.4) and higher scores were found among those who were female, younger and better educated (all p<0.01). Only 9% of the respondents knew that the law governing dentists and practice of dentistry in Hong Kong was amended recent at the end of 2024., while only 11% knew that it is illegal for beauty salons in Hong Kong to provide dental bleaching service. Conclusions: Most of the Hong Kong adults are dissatisfied with their tooth colour. They have a fair understanding of the common side effects of tooth whitening, but most of them lack sufficient knowledge on the limitations Besides, they are unfamiliar with the current legislation regarding provision of professional tooth whitening service in Hong Kong.