Introduction

Oral diseases are prevalent noncommunicable diseases, comprehending a major public health problem that affects approximately 3.5 billion individuals worldwide. Among children and adolescents, untreated dental caries is the most common oral disease, although other conditions, such as dental trauma and gingivitis, are observed. The mean worldwide prevalence of caries in deciduous teeth is 43%, corresponding to over 530 million affected children [1, 2], in the amount of 2.5 billion cases of untreated caries in the general population, in 2019 [2].

Despite the limitations of measuring and reporting the economic impacts of oral diseases, available data provides insights into their societal burden. These encompass direct treatment costs (direct cost), productivity losses due to absenteeism from work and school (indirect costs), and the impact on quality of life due to pain, difficulties with speaking, eating, and smiling (intangible costs) [3–5].

Regarding the direct costs of oral diseases it was estimated to correspond to 4.6% of global health expenditure in 2010 [3] and 2015 [5]. This proportion is likely understated, as the calculations were predicated solely on the three most prevailing conditions (untreated caries, severe periodontitis, and tooth loss) [3].

Considering the 2015 global economic burden of dental diseases, direct costs attributed to oral diseases reached USD 356.80 billion, and indirect costs related to severe periodontitis, severe tooth loss, and untreated caries amounted to $187.61 billion, totaling worldwide costs of $544.41 billion. Untreated caries accounted for 12% of global productivity losses due to oral diseases. Thereof 11% ($21.19 billion) involving permanent teeth, and 0,5% ($0.90 billion) affecting deciduous teeth [5].

To address this public health challenge, important decisions and actions have been taken, such as the historic resolution on oral health at the World Health Assembly, in 2021, the development and adoption of the Global Strategy on Oral Health, and the Global Oral Health Action Plan. These initiatives aim to achieve universal coverage of oral health services by 2030 [6].

School-based oral health-promoting programs play a crucial role in combating oral diseases and achieving universal coverage of oral health care. Globally, more than 90% of children in the primary school age group are enrolled in school, spending a significant portion of their time there [6]. Furthermore, schools can serve as the only primary access point for oral health services for children and adolescents, making oral health programs implemented in schools valuable for health promotion and equality [7, 8].

Oral health promotion can be effectively integrated into the school curriculum and activities as a foundation for developing Health Promoting Schools (HPS) [9]. HPS is recognized as a strategic approach for promoting positive development and healthy behaviors among students [6]. Integrating oral health promotion activities into schools benefits the participating children and extends to their siblings, parents, and the community, as they gain new knowledge and adopt healthier behaviors [10].

A comprehensive review aimed at identifying oral health promotion programs in schools across diverse countries and selecting the most suitable for local exigencies and resources revealed that oral health education emerged as the most frequently implemented intervention in school settings. It was followed by supervised toothbrushing, fluoride application, provision of nutritious meals, utilization of educational games, and dental screening activities [8].

A systematic literature review, undertaken to evaluate the efficacy of different school-based oral health-promoting programs concerning their impact on knowledge, attitudes, behaviors, oral health conditions, and quality of life of children and adolescents, highlighted the positive outcomes associated with the majority of these interventions. Particularly noteworthy were interventions involving oral health education, supervised toothbrushing, and provision of fluoride toothpaste and toothbrushes [11].

The HPS framework presents an efficacious and cost-effective alternative, yielding measurable and rapid results. The outcomes encompass enhancements in the rates of decayed, missing, and filled teeth (DMFT) [8, 10], advancements in oral health knowledge and practices, reduction in perceived halitosis, change in dietary preferences towards healthier choices, and increase in the consumption of nutrition foods among students [10].

However, a lack of studies evaluating the costs, cost components, and necessary resources associated with these school-based oral health-promoting programs hinders the decision-making process for large-scale adoption of such programs [12, 13]. Cost analyses, although scarce in this context, are essential for implementing evidence-based practices [14] and supporting decision-making [15]. Therefore, conducting precise and detailed cost studies to assess the resources needed for implementing and maintaining school-based oral health-promoting programs is necessary.

This systematic review of the literature (SRL) seeks to address this knowledge gap by assessing the cost components involved in school-based oral health-promoting programs. The review takes part in the planning for assessing the implementation costs of o health care proposed by the Affordable Health Initiative model of the Health Promoting School program (https://www.affordablehealthinitiative.com/resources-dental-health-care). The Affordable Health Initiative (AHI) is a Charitable Incorporated Organization in the United Kingdom that offers a simple, scalable, and sustainable operational model for the World Health Organization’s HPS initiative. The AHI HPS model recognizes and addresses the socio-economic and socio-psychological barriers to a healthy lifestyle, focusing efforts on hygiene, diet, physical activities, tobacco and drug use, and alcohol consumption, all of which are associated with several health outcomes [16].

Methods

This protocol follows the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol (PRISMA-P) [17] S1 Checklist. The protocol has been registered in the PROSPERO database (CRD42022363743).

Discussion

The systematic review, derived from the proposed protocol, aims to generate evidence on the cost components and required resources for implementing and sustaining school-based oral health-promoting programs. It emphasizes the significance of oral health interventions as a foundational element for successfully implementing the Health Promoting School (HPS) initiative in educational institutions. This evidence can potentially guide decision-makers in adopting the AHI HPS model on a broader scale in various countries and regions where its implementation has taken place. Ultimately, this widespread adoption can lead to improved access to primary oral healthcare for more children and adolescents, thereby enhancing their oral health outcomes.

While this review may contribute to the literature by describing the costs of school-based oral health-promoting programs, it will not be free from limitations. The definition and inclusion of various cost components can differ among studies, which can make it challenging to synthesize and compare cost data accurately. Consequently, this may make it unfeasible to conduct a meta-analysis. The review is also susceptible to publication bias, wherein studies featuring favorable or significant findings related to cost components might be more likely to be published, potentially leading to a bias in the literature being reviewed. In addition, there is no clear method to assess bias in reviews of economic evaluations, nowadays. To facilitate the comparability of results, a disaggregated presentation of the costs will be adopted, with all cost values being converted into Purchase Power Parity 2023 American Dollars (PPP-USD).

Supporting information

Acknowledgments

The authors would like to thank Dr. Fernanda Gomes Almeida, librarian at Universidade Federal de Minas Gerais, for her contribution, and pay posthumous tribute to Prof. Efigênia Ferreira e Ferreira, who integrated the review team and led the conceptualization of the study.