RCT on Effectiveness of Oral Health Preventive Programmes in School Children in Uganda

Study design

This randomized controlled clinical study will be developed in three parts: 1.) An epidemiological survey; a descriptive cross-sectional study to be conducted in Gulu Municipality to collect data on the oral health of school children to assess caries prevalence and associated factors. 2.) A field trial; an individually randomized, unblinded, two-armed trial of toothbrush/toothpaste/fluoride varnish versus education on nutrition/oral hygiene to assess the difference in treatment/prevention of dental caries. 3.) A comparison of oral health conditions among a group of children who were provided with dental cleaning tools and who were followed up and monitored over time versus a control group.

Study setting and location

The study will be conducted in Gulu Municipality, Gulu District, in Northern Uganda. The municipality has four sub-counties, each consisting of four parishes, with a total population of 177'400 according to the Uganda Bureau of Statistics (UBOS), 2020 projection [Uganda Bureau of Statistics in Uganda. April 2019 Population Projections by Subcounty and Sex (2015-2030), in Population \& Censuses. 2019]. It is the largest urban center in Acholi sub-region. There are three hospitals offering oral health services in Gulu Municipality: Gulu referral hospital, St. Mary's Hospital, Lacor and Gulu independent hospital. Primary schools in Gulu Municipality will be used as study areas. The list of primary schools in the Municipality will be obtained from the District Education Officer (DEO). An ethical approval from the Ministry of Health and consents from parents of the school children will be required.

Study population

The study will be conducted among school children in Gulu Municipality for 24 months, starting in September 2024. The inclusion criteria will be: enrollment in one of primary schools in Gulu Municipality, age between 5 and 17 years, staying in the area for at least six months and parent/guardian's willingness to give consent. Exclusion criteria will be: school children who refuse to participate in the research and/or parents who refuse their children's participation and children with chronic diseases or systemic conditions that require differential care and follow-up.

Data collection

A modified World Health Organization (WHO) questionnaire on children oral health [Oral health surveys: basic methods. 2013: World Health Organization.] will be used for each participant to identify factors such as socioeconomic status, dietary habits, oral health habits, and dental attendance associated with oral health data.

The dental examinations will be performed by five trained and calibrated dentists. These will receive an intensive two-day training session of at least 72 hours together with a demonstration on images depicting carious lesions of varying severity in order to learn how to assess them through the International Caries Detection and Assessment System [Dikmen, B., ICDAS II criteria (International Caries Detection and Assessment System). Journal of Istanbul University Faculty of Dentistry, 2015;49(3):63.].

A benchmark examiner will calibrate the examiners' practice on caries detection to ensure accurate and correct application of the research procedures. The first ten enrolled participants will be used for calibration exercise. The unweighted kappa statistic will be used to assess the inter-examiner and intra-examiner agreement. The dental examination will be carried out using a mirror and a probe, under appropriate artificial light and after cleaning the teeth with cotton rolls to remove food debris and dental plaque. Oral health status will be evaluated according to the method and criteria recommended by the WHO [Oral health surveys: basic methods. 2013: World Health Organization.], including the ICDAS [Dikmen, B., ICDAS II criteria (International Caries Detection and Assessment System). Journal of Istanbul University Faculty of Dentistry, 2015;49(3):63.].

The following data will be collected after obtaining consent and enrolment:

• Date of enrolment
• Date and time of consent
• Participant identifiers
• Socio-economic and demographic information
• Status of the oral health

Follow up visits:

• All participants will be re-assessed clinically every three months after enrolment until the 24th month to evaluate oral health status. A symptom checklist, targeted dental examinations and a record of the findings and treatments administered will be performed at each visit.
• All costs related to the health care of the project participants will be recorded, starting from enrolment and for the duration of follow-up. The costs will also include those for any hospitalisation related to dental caries and those arising from the use of other health care resources, including the costs of materials used for each visit.

Project variables

The first part of this project is an epidemiological survey in which the prevalence of dental caries will be the primary outcome. The outcome will be calculated by determining the percentage of participants diagnosed with dental caries, while the secondary outcome will be the extent of other oral diseases. The mean values of carious teeth/surfaces, missing teeth/surfaces, filled teeth/surfaces and mean DMFT/S will be calculated. A questionnaire will be used to investigate the relationships between the prevalence of dental caries and other variables such as sex, demographic information, school, age, hygiene habits (brushing frequency), maternal education, dietary habits (frequency of mealtimes, frequency of sugar intake, sugar intake between meals, soft drink consumption between meals).

The second phase of the project is a field trial in which the outcome variable will be the presence of dental caries after the intervention. Secondary outcomes will include resolution of dental caries symptoms, cost of interventions performed.

A full study protocol will be published in a peer-reviewed journal in a timely manner and will be included here afterwards.