Barriers and enablers in the implementation and sustainability of toothbrushing programs in early childhood settings and primary schools: a systematic review

Dental caries is one of the most prevalent non-communicable diseases of global public health concern affecting children [1]. The Global Burden of Disease study (2017) has reported an estimated 530 million children had tooth decay in their primary teeth [2]. In Australia, dental caries is recognised as a non-fatal burden of oral disease and significantly affects children aged 5–14 years [3]. According to the Australian National Child Oral Health Study, more than 25% of children aged 5–10 years had untreated dental caries in their primary teeth, and approximately one in ten children aged 6–10 years had dental caries in the permanent teeth [4]. This problem of dental caries is not unique to Australia. In the United Kingdom (UK), the national child dental health surveys have reported limited change in the prevalence of dental caries over the period of the last 20 years among five-year-old children [5]. In 2019, the Oral Health Surveillance Report from the United States of America concluded little change in the prevalence of dental caries among 2–8-year-old children from 1999–2004 and 2011–2016 [6]. Untreated dental caries impacts a child's quality of life including overall health and wellbeing, growth and development, social interaction, and poor school attendance [7, 8].

Dental caries has a multifactorial etiology with key factors such as the frequent consumption of sugary diet, inadequate exposure to fluoride, and inadequate toothbrushing [9]. Moreover, social determinants of poor oral health such as deprived socioeconomic status increase the risk of dental caries in children [10, 11]. Despite the high burden of dental caries in children, it is worthy to note that dental caries is preventable [12]. Effective preventive measures for dental caries in children require the adoption of oral health promoting behaviours such as a low sugar diet, twice-daily toothbrushing with age-appropriate fluoridated toothpaste, and regular dental visits [9].

Childhood and adolescence are the most influential stages of developing healthy behaviours [13]. The oral health-related attitudes, beliefs, and behaviours developed this period will potentially be sustained throughout life [13]. Apart from fluoridated water, toothbrushing with a fluoride toothpaste is one of the most readily available form of fluoride [14] and twice daily toothbrushing with a fluoride toothpaste has proven to be effective in preventing caries [15]. Therefore, several toothbrushing programs have been implemented in early childhood settings (such as day-cares and pre-schools) and primary schools to reduce the burden of oral health disparities in children. For example, a once daily school-based toothbrushing program in London showed the overall caries increment in the interventional group (2.60) was significantly less (p < 0.001) than children in the control group without intervention (2.92) [16]. Likewise, a toothbrushing educational programs in preschools demonstrated significant reduction in plague and caries development among children in experimental group than controls (non-intervention groups) [17]. It is worth noting toothbrushing programs are not unique to high-income countries. For instance, a school-based oral health promotional program in Uganda revealed remarkable improvement in school children's oral health by reporting fewer incidents of dental pain, emergency dental visits and significant improvement in their school attendance [18].

Several systematic reviews have been undertaken to assess oral health interventions in early childhood and school settings; however, the none of the reviews explain the barriers and enablers in the implementation and sustainability of the toothbrushing programs [19‐22]. Most of these reviews draw evidence from randomised controlled trials (RCT) [20, 21] and quasi-RCTs [19] except for scoping reviews [22] which draw evidence from international guidelines and toothbrushing programs. The outcomes of these reviews were based on the effectiveness of oral health or toothbrushing programs on the incidence of dental caries [19, 21] or improvement in oral hygiene [20, 21]. Most of these reviews searched the evidence for both children and adolescents and did not distinguish research findings specifically for children alone [19, 21]. Moreover, all these reviews rated “critical low” when their methodological quality appraisal was conducted by using AMSTAR 2 tool (see Additional file 1: Appendix 1). The limitation in these previously published reviews demands the need for a high-quality systematic review to identify barriers and enablers in the implementation and sustainability of toothbrushing programs in early childhood settings and primary schools.

The term implementation is defined as for the improvement of the population health, the utilisation of strategies for the change or the introduction of evidence-based health interventions (EBIs) within targeted settings [23]. An evaluation of these adopted and used EBIs strategies in specific settings such as schools, healthcare facilities, or workplaces for the population health sustainability is known as implementation science (IS) [24]. In addition to assessing the effectiveness of school-based oral health program’s [19, 21], it is imperative to understand the enablers and challenges of program implementation for the optimisation of program benefits, sustainability, and dissemination of the findings to other settings [25]. The Implementation research utilises variety of frameworks such as the consolidated framework for implementation research (CFIR), exploration, preparation, implementation, and sustainment (EPIS), reach, effectiveness, adoption, implementation, and maintenance (RE-AIM), and practical, robust, implementation sustainability model (PRISM) [26]. Among other IS frameworks, the utilisation CFIR is the most robust strategy to understand the school-based toothbrushing programs enablers and challenges, because CFIR is a meta-framework and combines elements from other IR frameworks, making it more comprehensive [27]. Moreover, CFIR is widely used worldwide for process evaluation, which relays on understanding how the intervention is implemented and the factors influencing the implementation of intervention [26].The CFIR suggests the implementation is influenced by the intervention characteristics (e.g., implementation decisions, evidence, adaptability, relative advantage, design quality, complexity, and cost), inner settings (e.g., organisational structure, culture, networks, and communications, implementation environment and readiness for implementation), outer settings (e.g., participants needs, cosmopolitanism, external policy, peer pressure, and incentives), the stakeholders involved (e.g., knowledge and belief related to intervention, implementation skills, self-efficacy, personal attributes and identification with the organisation) and the implementation process (e.g., coordination, engagement, execution to plan, reflection and evaluation) [27]. This framework highlights that implementation is a critical process between the decision of an organisation to adopt an intervention and the willingness of the stakeholders to utilise the intervention in routine. Although the Consolidated Framework for Implementation Research [25] is useful, limited evidence exists on the implementation of oral health interventions such as toothbrushing programs in early childhood settings and primary schools. Therefore, the objective of this systematic review is to understand the barriers and enablers to the implementation and sustainability of toothbrushing programs in early childhood settings (such as day care and preschools) and primary schools.

This review has been reported according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines [28]. The protocol of this systematic review has been registered and published with the PROSPERO International Prospective Register of Systematic Reviews (CRD42022312080) [29]. Initially, the eligibility criteria of the systematic review protocol only included the oral health promotional studies conducted in preschool and primary school settings. Later, the amendment was made and early childhood settings were also added as a part of review eligibility criteria.

A total of 10,040 studies were retrieved from the five electronic databases (n = 10,030) and citation chasing (n = 10). After the removal of duplicates, 5592 studies were retained for further reading. Of these, 4641 studies were excluded after reviewing the titles and abstracts of the studies and a total of 23 full-text studies were retrieved for reading. Of these, six studies were included in the review. The excluded studies (n = 17) and the reasons for exclusion are summarised in Additional file 5: Appendix 5. The PRISMA flow diagram shows the identification, screening, eligibility, and included studies in Fig. 1.

This review aimed to identify the key barriers and enablers to implementation and sustainability of toothbrushing programs in early childhood settings and primary schools. A total of six studies fulfilled the review eligibility criteria and were thereby included in this review. These studies were conducted in early childhood settings and primary schools with established toothbrushing activities targeting children aged 3–12 years. By adopting diverse data-collection techniques, these studies collected data from different stakeholders (including schoolteachers and staff, parents, children, health promoters, and volunteers). The key barriers and enablers were identified at an organisational, school staff, parents, and children’s level.

The findings of this review indicate it would be beneficial for policymakers to mandate oral health education in early childhood settings and primary schools’ curricula. The findings recommend policymakers and researchers undertake active community engagement in designing oral health promotion programs in early childhood settings and primary schools. Furthermore, the implementation of oral health interventions and toothbrushing activities need to consider the following to ensure success in program implementation and sustainability: linking toothbrushing activities with the home environment, active engagement of all stakeholders (organisation, teachers and staff, parents, and children), and training of school teachers, integration of oral health programs with other health programs, involvement of community volunteers and peer leaders, and active involvement of oral health promoters.

This review’s findings are also beneficial for teachers to recognise their role in integrating oral health information and toothbrushing activities into their curriculum and pedagogical practices. Moreover, these findings are helpful for parents as they play a crucial role in developing health-promoting behaviours early on in their child's life and sustaining them over time. Furthermore, parents may help to motivate their children to actively participate in school-based toothbrushing activities and continue healthy oral habits at home.

Early childhood settings and primary schools are good settings for the establishment of good oral health-promoting behaviours such as toothbrushing. This review highlights the key enablers and barriers of implementation and sustainability of toothbrushing programs at multiple levels—organisational, teachers and school staff, parents, and children. A positive attitude of the school staff; the flexibility of toothbrushing sessions; the involvement of community volunteers and parents were a few of the identified enablers. However, the timing of the communication of the program, inadequate transfer of information among school staff, frequent school staff turnover, lack of parental support, and teachers feeling overburdened while acting as pseudo parents were frequently reported barriers. These aspects need to be considered for the planning, implementation, and sustainability of toothbrushing programs in such settings.