Personalized oral care (Precaries): an intervention study customized according to genetic cause and risk

ABSTRACT Introduction Dental caries is a disease that affects billions of people, and involves high and low genetic susceptibility phenotypes and different causal subtypes. The randomized clinical trial Precaries-RCT will evaluate caries prevention in adolescents, customized according to genetic cause and risk. Here we describe the Precaries-RCT and two nested Precaries studies for cost-efficient oral healthcare and personalized dentistry. Methods and analysis Here we present a basic and adaptive protocol for the Precaries-RCT multicentre caries intervention study, customized according to genetic cause and risk. It includes prescreening for high versus low genetic caries susceptibility, through self-performed sampling by mail of up to 2000 adolescents aimed for orthodontic treatment at community clinics, of which 520 are enrolled in the RCT. The participants are allocated into two groups — a high and a low genetic caries susceptibility group — that each is assigned to intensive or standard prevention. The primary outcome is % reduction in caries increment, relative to prevention and genotype, with caries outcomes measured using tactile and visual methods, bitewing radiographs, clinical photos, and quantitative laser fluorescence. The adaptive design allows for determination of incidence and progression rates and for inclusion of additional human and microbiota biomarkers and study subjects. Biological samples (e.g. swab DNA, whole and parotid saliva, and microbiota) and questionnaire data are collected. Here we also outline the nested Precaries-adolescent sample for mining of predictor and therapeutic target genes and Precaries-birth cohort samples for implementation of our findings in childhood. Ethics and dissemination Ethical approval was obtained from the Swedish national board research ethics committee (Dnr 2020-02533). Informed consent will be obtained from each participant. The findings will be disseminated to the public through conference presentations and publication in peer-reviewed scientific journals. Trial registration number www.clinicaltrials.gov, NCT05600517