https://orcid.org/0000-0003-0719-4189
Figures
Abstract
Background
Schools offer an opportunity for oral health promotion in children and adolescents. The purpose of this study was to conduct a systematic review of the influence of school-based oral health promotion programmes on oral health knowledge (OHK), behaviours (OHB), attitude (OHA), status (OHS), and quality of life (OHRQoL) of children and adolescents.
Methods
A systematic search on the PubMed and Embase databases was conducted to identify eligible studies. The last search was done on April 24th, 2020. The quality of the included studies was evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal tools.
Results
Of the 997 articles identified, 31 articles were included in this review. Seven studies targeted students in preschools, seventeen in elementary schools, and seven in high schools. Most of these studies revealed positive outcomes. Some studies showed that the school-based oral health promotion programmes showed better OHK, OHB, OHS, and OHRQoL.
Citation: Bramantoro T, Santoso CMA, Hariyani N, Setyowati D, Zulfiana AA, Nor NAM, et al. (2021) Effectiveness of the school-based oral health promotion programmes from preschool to high school: A systematic review. PLoS ONE 16(8): e0256007. https://doi.org/10.1371/journal.pone.0256007
Editor: Susan R. Rittling, Forsyth Institute, UNITED STATES
Received: October 9, 2020; Accepted: July 28, 2021; Published: August 11, 2021
Copyright: © 2021 Bramantoro et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the manuscript and its S1 Checklist.
Funding: Yes - Universitas Airlangga.
Competing interests: The authors have declared that no competing interests exist.
Introduction
Oral diseases pose a significant public health challenge, especially among children and adolescents. Around 60–90% of school children worldwide suffered from caries [1] and over 531 million children had caries of deciduous teeth [2]. Moreover, most children and adolescents showed gingivitis symptoms. Approximately 2% of youth had aggressive periodontitis, which might lead to premature tooth loss [1]. Oral diseases can negatively affect the quality of life, cause pain, limitation in oral functions, impaired nutrition, emotional stress, low self-esteem, and poor school attendance and performance [3–6]. They also impose a considerable economic burden as oral health treatments are often expensive. The treatment cost of dental caries alone for children was estimated to surpass the total budget of healthcare for children in low-income countries [7].
One of the efforts to improve the oral health of children and adolescents is by implementing school-based oral health promotion programmes, as proposed by the World Health Organisation (WHO) [8]. Schools serve as ideal settings for health promotion as they can reach most school-aged children and provide important networks to their families and communities [8, 9]. School-based programs can also help increase children’s access to dental services, especially those from disadvantaged socio-economic backgrounds [10]. Moreover, school years cover the life period of childhood and adolescence, during which lifelong sustainable behaviours, beliefs, and attitudes related to health are established [8].
Several school-based oral health promotion programmes have been proposed, such as oral health education (OHE), tooth-brushing activities, the provision of fissure sealant, or other treatments [11, 12]. While the effectiveness of the programs has been investigated, extensive evidence from a global viewpoint is still limited. Moreover, existing systematic reviews only focused on OHE [13–15]. A study providing a complete picture of the effectiveness of different kinds of oral health programmes at various school settings has not yet been available. This information is necessary to help the development of policies and the allocation of resources [13].
The objective of this study was to systematically review the effectiveness of the school-based oral health promotion programmes on oral health knowledge (OHK), behaviours (OHB), attitude (OHA), status (OHS), and quality of life (OHRQoL) of children and adolescents at preschools, elementary schools, and high schools.
Materials and methods
We systematically reviewed a series of published articles to answer the question–What is the significance of school-based oral health programmes on children and adolescents?
We chose the eligible articles according to the following criteria:
- All types of experimental studies (randomised controlled trials, quasi-experimental studies)
- Written in English;
- Study subjects were pre-schoolers, school children, and school adolescents;
- The intervention included all types of oral health intervention programmes conducted in preschools, elementary schools, or high schools;
- The outcome was OHK, OHB, OHA, OHS, and OHRQoL.
There was no limitation on publication year. Protocols, reviews, editorial letters, and commentaries were excluded.
Search strategy
PubMed and Embase were chosen as the database sources for our study, as they are considered to be the largest pharmaceutical and biomedical databases. The last search was on April 24th, 2020. We used search terms related to oral health promotion, school, children, adolescents, randomised controlled trial, quasi-experimental study, OHK, OHB, OHA, OHRQoL, oral hygiene, and oral diseases, such as caries, periodontitis, and toothache.
Study selection, data extraction, quality assessment
Two independent reviewers performed the study selection, data extraction, and assessment of the quality of studies. After the records were obtained from the databases and duplicates were eliminated, the titles and abstracts were screened based on the selection criteria. A full-text review was then conducted to identify eligible studies. Data of the included studies was recorded (i.e., author, publication year, country, school setting, study population, interventions, comparator or control group, and results). The quality of the included studies was evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal tools for randomised controlled trials and quasi-experimental studies [16]. Any disagreements or ambiguities were resolved through discussion.
Results
A total of 997 records were obtained from the databases. After removing duplicates and screening titles and abstracts, 37 articles remained for the full-text review. Of these, 31 studies met the eligibility criteria and were included in our review. The flow diagram of the study selection process can be seen in Fig 1.
Characteristics of the studies
The included studies in this review were from four distinct regions, which were Asia, Europe, Africa, and America. The two largest proportions were from Asia (48%) and Europe (26%). Of the 31 studies included, four were from the United Kingdom; 3 of each were from the following countries: Iran, Brazil, China; 2 of each were from the following countries: India, Pakistan, Hong Kong, and Germany; and one of each was from the following countries: Myanmar, Thailand, Turkey, Switzerland, Sweden, Argentina, the United States, Nigeria, Tanzania, and Zimbabwe. The publication year varied from 1976 to 2019. Twenty-seven studies used randomised clinical trial designs, while four studies used quasi-experimental designs. Seven studies targeted the student populations in preschools, seventeen studies in elementary schools, and seven studies in high schools. All the included studies had sufficient methodological quality.
The effects of school-based oral health promotion programmes on children.
1. Preschool children. Table 1 shows the summary of studies conducted in preschools. Intervention in all studies involved delivering oral health information to children. OHE for teachers was conducted in three studies [17–19], and for parents in two studies [18, 19]. One study investigated the effectiveness of education through games and puppet shows [20], one study on the methods of education (either delivered by a teacher, a dentist, or role-playing dental residents) [21], one study on a specific tooth-brushing instruction [22], and one study on professional cross-brushing on first permanent molar surfaces [23]. Four studies included supervised tooth-brushing [17–19, 23], two studies included the provision of fluoridated toothpaste and toothbrushes [17, 18], and one study included the application of sodium fluoride phosphate [19] as part of their interventions.
Delivering education through games and shows resulted in significantly better oral hygiene knowledge and skills than verbal instructions [20]. Children receiving a role-playing or drama mode of health education had significantly better oral hygiene than those without interventions or those receiving conventional education from a dentist or a trained teacher [21]. A specific instruction on oral hygiene is proven to significantly improve children’s oral hygiene [22]. The addition of educational programmes for parents, teachers, and children as a support to the preventive programmes (application of sodium fluoride phosphate, supervised toothbrushing with fluoride) led to the significant reductions in gingival index and plaque index scores and no changes in dmft and dmfs scores. Meanwhile, the group without the addition of educational programmes showed significant increases in gingival index, plaque index, dmft, and dmfs scores [19].
Compared to the control group, the group which received a school programme covering OHE for children, teachers, and parents, a supervised toothbrushing, and provision of fluoridated toothpaste and toothbrushes had 30.6% lower dmfs increment and a higher percentage of children brushing twice a day [18]. A similar programme, comprising of OHE for children and teachers, supervised tooth brushing, and the use of 1100 ppm fluoride dentifrice, also led to a significantly lower dmfs increment than the control group [17]. Among boys, the school-based supervised tooth-brushing programme that also covered professional cross-brushing on the first permanent molar surfaces led to 50% lower caries incidence density compared to the group receiving only the conventional tooth-brushing programme at school [23].
2. Elementary school children. Table 2 shows the summary of studies conducted in elementary schools. Six studies focused on the effectiveness of the OHE programmes [11, 24–28], one study on the importance of repetition and reinforcement [29], three studies on supervised toothbrushing [30–32], one study on tooth-brushing training [33], one study on school dental screening [34], and two studies on SOC-based interventions [35, 36]. Besides involving education as part of the interventions, one study further included dietary counselling, the ingestion of fluoridated drinking water, and supervised toothbrushing [37], one study included a dental hospital tour programme [12], two studies included the provision of preventive and restorative care [12, 37], three studies included the provision of oral hygiene aids [12, 25, 37], and two studies included competition activities [12, 38].
OHE that was incorporated into a school curriculum lowered the risk of developing new carious lesions by 35%. However, the effect was modified by parental socioeconomic status (SES) since high SES in the intervention group was associated with a 94% incidence rate ratio (IRR) reduction [24]. One-time teacher training on oral health did not significantly make differences in means of plaque and caries increment scores compared to the control group [26].
A programme consisting of OHE, teacher supports, and competition had a significant effect on OHK and an effect on OHRQoL [38]. Those with a comprehensive programme of OHE for children and parents, a contest, dental hospital tour, oral examination, provision of fluoride toothpaste, and preventive and curative treatments showed significantly lower DMFS increment mean score, untreated dental caries scores, higher reductions in plaque and sulcus bleeding scores, higher proportions in restoration and sealants, and showed changes towards good practices of oral care compared to the control group [12]. Children receiving a comprehensive needs-related oral hygiene training programme had significantly less gingival bleeding and plaque than the control group, whereas there were no differences found between the less comprehensive group and the control group [25]. Children with a comprehensive OHE targeted for them, their parents, and teachers had significantly better OHB, oral hygiene, and gingival health status than other groups. Children with OHE targeted for only them had significantly better OHB and oral hygiene than the control group, but there was no difference in terms of gingival health [11]. OHE via parents at home or the combination between parental involvement and class activities significantly improved oral hygiene and gingival health status compared to the control group. Meanwhile, no significant differences were observed between the class-work group and the control group [28].
Groups receiving OHE led by dentists, teachers, or peers had significantly better OHK, OHB, and oral hygiene status than self-learning or control groups. There were no significant differences in OHK and oral hygiene status between the three educator-led groups. Nevertheless, the peer-led group had a significantly better OHB than the teacher-led group. The self-learning group had a significantly better OHB than the control group, but there were no differences in OHK and oral hygiene status between them [27].
One-time OHE session had no significant effect on oral hygiene status, regardless of the educators. One-time dentist-led and peer-led OHE sessions significantly increased OHK and OHB related to gingivitis, but there was no significant change in OHB related to oral cancer. One-time teacher-led OHE session had no significant effects on OHK and OHB. However, six months after repeated and reinforced OHE (RR-OHE), the OHK, OHB, and oral hygiene status significantly improved, regardless of the educators. Although 12 months after the RR-OHE, the OHK of the dentist-led and peer-led groups significantly decreased, there were no significant changes in the OHK of the teacher-led group, as well as in the OHB and oral hygiene status of all the groups [29].
An individual tooth-brushing training programme significantly improved children’s brushing skills compared to the control group [33]. Children receiving a programme of tooth brushing with fluoride toothpaste supervised by teachers had a significantly less overall caries increment than those in the control group [31]. The provision of brushing sessions from trained teachers and curative dental care on-demand significantly reduced the plaque and gingival bleeding scores. The reductions of scores were comparable between chewing stick and toothbrush users [30]. One quasi-experimental study in Burma found that a school-based tooth-brushing programme had no significant effects on plaque and bleeding scores [32].
Children receiving a 2-month sense of coherence (SOC) intervention from trained teachers had significantly better OHRQoL and SOC improvement than the control group [35]. Another study also found that the SOC intervention group had significantly better OHRQoL, SOC, oral health beliefs, and gingival health than the control group [36]. The provision of five preventive and therapeutic measures significantly reduced caries increment compared to the provision of three preventive measures only [37]. School dental screening, followed by a series of communication to encourage parents into taking their children to a dentist significantly improved dental attendance [34].
3. High school children. Table 3 shows the summary of studies conducted in high schools. Two studies investigated the effectiveness of education through posters or pamphlets [39, 40]. Besides including education as part of the interventions, one study further explored the effectiveness of the provision of oral hygiene aids [41] and one study on the use of the different types of oral hygiene instruments [42]. There was one quasi-experimental study on the evaluation of the Natural Nashers programme in England [43], one study on the effectiveness of motivational interviewing [44], and one study on the involvement of dental hygienists at schools (education, open clinic, including fluoride varnish treatments) [45].
A two-week display of educational posters concerning dental trauma significantly improved knowledge on dental trauma management [39]. Children receiving a loss-framed pamphlet intervention had better OHB, attitude, and intention to brush at a 2-week follow-up, less dental plaque, better OHRQOL, and gingival health at a 24-week follow-up compared to other groups [40]. The Natural Nashers programme generally reduced children’s plaque and gingival scores and improved their OHK and OHA compared to the control group [43]. Frequent teacher-led OHE sessions along with the provision of oral hygiene aids significantly reduced simplified oral hygiene index (OHI-S), plaque index (PI), and gingival index (GI) scores. In contrast, these scores significantly increased among those receiving infrequent dentist-led OHE sessions or those without intervention. There was no pre-post difference in mean DMF-S score for all groups [41].
Dental hygienists working in schools to deliver OHE and preventive measures (fluoride varnish treatments) impacted the incidence of enamel caries, but there was no effect on dentin caries. The intervention also improved OHK and oral hygiene, but there was no effect on attitudes toward tobacco [45]. Following OHE programme, children who were assigned to use toothbrushes had a higher gingivitis occurrence than those assigned to use chewing sticks in Nigeria [42]. Children receiving a motivational interviewing session had a lower number of new carious teeth, tended to reduce snacking, and increased their tooth-brushing frequency compared to those who received a traditional OHE. The inclusion of caries risk assessment into motivational interviewing provided additional effects only on oral hygiene, but not on the other outcomes [44].
Discussion
This study was among the few to provide a comprehensive summary of the effectiveness of oral health promotion programmes in different school settings, ranging from preschools to high schools. One of the limitations was the restriction to take into account only the studies published in English, which might cause language bias. The search for conference proceedings, dissertations, and unpublished studies was not performed. It was challenging to summarise the findings of the studies due to high variabilities in the type and method of interventions, outcome measurements, and age of the samples. Thus, it was not feasible to provide a quantitative comparison, as reported by a previous review [15]. The strategy or design of oral health promotion programs rather varies across countries, depending on the financing and planning of the health and education sectors, the socioeconomic condition, culture, and the burden of oral diseases in the country [46].
According to WHO, schools are ideal settings to promote oral health. An individual spends most of their childhood and adolescence time at schools. This period is a critical stage of the life course, during which behavioural patterns are built, and that may indicate their future health status. Moreover, children can learn new information rapidly at this stage. The sooner habits are formed, the longer the impacts last. The messages conveyed in health promotion programmes can be repeated regularly during the school period [8]. Besides helping children to develop personal skills to choose a healthy lifestyle, oral health promotion may support the creation of a healthy school environment [8, 47, 48]. It is suggested that school-based oral health programs with multiple levels of influence may advance oral health equity [10].
One of the considerations in designing health education is the age group of the target population. In preschools, OHE sessions that were delivered through fun activities (i.e., via games, drama) were more effective in improving children’s oral hygiene [21], knowledge, and skills [20] than the traditional OHE. Activities designed to match children’s developmental levels and interests allow them to learn faster. Through playing, children’s motor and cognitive processes of learning progress more rapidly and at an advanced level [20]. Moreover, OHE that is given not only for the children but also for the teachers and parents, will encourage children to adopt a good OHB both at school and home. It was found that a comprehensive programme consisting of OHE sessions to children, teachers, and parents, and supervised tooth brushing with fluoride toothpaste, improved children’s OHB and OHS [17–19]. A professional cross-brushing on first permanent molar surfaces was also found to reduce caries [23].
Similarly, among elementary young students, a programme involving OHE for children, teachers, and parents, was the most effective [11, 25, 28]. In terms of educators, a dentist-led, a teacher-led, and a peer-led OHE were equally effective in improving OHK and oral hygiene status, but the peer-led OHE was better than the teacher-led OHE in enhancing OHB [27]. Another study, however, gave more emphasis to the importance of repetition and reinforcement in OHE than to the educators [29]. The effectiveness of combined approaches of OHE and other interventions, such as the provision of preventive and restorative care, fluoride toothpaste, fluoridated drinking water, a tour of a dental hospital, and competition were also observed in several studies [12, 37, 38]. School dental screening, followed by a series of communication to encourage parents into taking their children to the dentists was effective in improving dental attendance [34].
The positive impacts of tooth-brushing activities were well-demonstrated [30, 31, 33], except for a study in Myanmar that found no impacts following the programme. It was suggested that the factors behind these findings might be the teachers’ lack of skills in giving the instructions as they were not dental professionals, the fact that instructing some groups of young children were not that effective, and children under ten years’ lack of ability to brush [32]. Another type of intervention was a SOC-based intervention, which was found to improve OHRQoL, SOC [35, 36], gingival health, and oral health beliefs [36]. SOC might influence health through physiological (less stress, less physical or biological effects), behavioural (selection of favorable behaviours), and emotional (better ability to cope with stress) pathways [36]. The effectiveness of this intervention was consistently reported in two studies from different countries (i.e., Brazil and Thailand) [35, 36].
Among adolescents, the educational poster was effective in improving knowledge. Nonetheless, the follow-up period in this study was only two weeks [39]. In terms of message framing, loss framing was better than gain framing in encouraging OHB among Iranians. It is worth mentioning, however, that the effects of message framing may depend on the cultural backgrounds, varying between countries [40]. The importance of repetition and reinforcement in OHE, as well as the provision of oral hygiene aids, were also demonstrated [41, 43]. Close monitoring was especially needed when unfamiliar oral hygiene procedures were introduced [42]. An intervention that is noted to be more effective than the traditional OHE for adolescents was motivational interviewing, which was a person-centered counseling strategy [44]. Meanwhile, a programme involving dental hygienists in Sweden was found to have limited impacts on caries incidence, knowledge, and attitudes, but improved adolescents’ interest in oral health. It was suggested that the participants had already had a favourable knowledge and attitude, and a low caries prevalence at baseline, making further improvement difficult to achieve [45].
In summary, most studies found that the intervention programmes brought positive outcomes, especially those involving OHE for children, teachers, and parents, supervised toothbrushing, and provision of fluoride toothpaste and toothbrush. The role of repetition and reinforcement in OHE is highlighted, which is possible through continuous programmes. It may also be beneficial to deliver OHE to pre-schoolers through fun activities. Besides the teacher, parental involvement plays a role in determining the success of the programmes, which may indicate the need to conduct oral health training for them. Future studies that assess the efficacy of home-based oral health promotion programs among children and adolescents will be useful to provide more evidence in developing integrated oral health promotion programmes.
Acknowledgments
We thank the librarian of the University of Adelaide for the help with the search strategy and the provision of full-text articles.
References
- 1.
Petersen PE, Bourgeois D, Ogawa H, Estupinan-Day S, Ndiaye C. The global burden of oral diseases and risks to oral health. Bulletin of the World Health Organization. World Health Organization; 2005. pp. 661–669. https://doi.org//S0042-96862005000900011 pmid:16211157
- 2. James SL, Abate D, Abate KH, Abay SM, Abbafati C, Abbasi N, et al. Global, regional, and national incidence, prevalence, and years lived with disability for 354 Diseases and Injuries for 195 countries and territories, 1990–2017: A systematic analysis for the Global Burden of Disease Study 2017. Lancet. 2018;392: 1789–1858. pmid:30496104
- 3. Alsumait A, ElSalhy M, Raine K, Cor K, Gokiert R, Al-Mutawa S, et al. Impact of dental health on children’s oral health-related quality of life: A cross-sectional study. Health Qual Life Outcomes. 2015;13: 98. pmid:26149439
- 4. Kaur P, Singh S, Mathur A, Makkar DK, Aggarwal VP, Batra M, et al. Impact of Dental Disorders and its Influence on Self Esteem Levels among Adolescents. J Clin Diagnostic Res. 2017;11: ZC05. pmid:28571250
- 5.
World Health Organisation—Regional Office For Europe. Diet and Oral Health. [cited 24 Jul 2020]. Available: https://www.euro.who.int/__data/assets/pdf_file/0009/365850/oral-health-2018-eng.pdf
- 6. Jackson SL, Vann WF, Kotch JB, Pahel BT, Lee JY. Impact of poor oral health on children’s school attendance and performance. Am J Public Health. 2011;101: 1900–1906. pmid:21330579
- 7. Yee R, Sheiham A. The burden of restorative dental treatment for children in Third World countries. Int Dent J. 2002;52: 1–9. Available: https://pubmed.ncbi.nlm.nih.gov/11931216/ pmid:11931216
- 8.
World Health Organisation. WHO Information Series on School Health—Oral Health Promotion: An Essential Element of a Health-Promoting School. Geneva; 2003. Available: https://apps.who.int/iris/bitstream/handle/10665/70207/WHO_NMH_NPH_ORH_School_03.3_eng.pdf?sequence=1&isAllowed=y
- 9.
World Health Organisation. School health services. [cited 25 Jul 2020]. Available: https://www.who.int/maternal_child_adolescent/adolescence/school-health-services/en/
- 10. Gargano L, Mason MK, Northridge ME. Advancing Oral Health Equity Through School-Based Oral Health Programs: An Ecological Model and Review. Front Public Heal. 2019;7: 359.
- 11. Yekaninejad MS, Eshraghian MR, Nourijelyani K, Mohammad K, Foroushani AR, Zayeri F, et al. Effect of a school-based oral health-education program on Iranian children: results from a group randomized trial. Eur J Oral Sci. 2012;120: 429–437. pmid:22985001
- 12. Tai B-J, Jiang H, Du M-Q, Peng B. Assessing the effectiveness of a school-based oral health promotion programme in Yichang City, China. Community Dent Oral Epidemiol. 2009;37: 391–398. pmid:19624698
- 13. Nakre P, Harikiran A. Effectiveness of oral health education programs: A systematic review. J Int Soc Prev Community Dent. 2013;3: 103. pmid:24778989
- 14. Geetha Priya P, Asokan S, Janani R, Kandaswamy D. Effectiveness of school dental health education on the oral health status and knowledge of children: A systematic review. Indian J Dent Res. 2019;30: 437. pmid:31397422
- 15. Habbu SG, Krishnappa P. Effectiveness of oral health education in children—a systematic review of current evidence (2005–2011). Int Dent J. 2015;65: 57–64. pmid:25345565
- 16.
Tufanaru C, Munn Z, Aromataris E, Campbell J, Hopp L. Chapter 3: Systematic reviews of effectiveness. In: Aromataris E, Munn Z, editors. Joanna Briggs Institute Reviewer’s Manual. The Joanna Briggs Institute; 2017. Available: http://joannabriggs.org/research/critical-appraisal-tools.html
- 17. You BJ, Jian WW, Sheng RW, Jun Q, Wa WC, Bartizek RD, et al. Caries prevention in Chinese children with sodium fluoride dentifrice delivered through a kindergarten-based oral health program in China. J Clin Dent. 2002;13: 179–184. pmid:12116728
- 18. Rong WS, Bian JY, Wang WJ, Wang J De. Effectiveness of an oral health education and caries prevention program in kindergartens in China. Community Dent Oral Epidemiol. 2003;31: 412–416. pmid:14986908
- 19. Hochstetter AS, Lombardo MJ, D’eramo L, Piovano S, Bordoni N. Effectiveness of a preventive educational programme on the oral health of preschool children. Promot Educ. 2007;14: 155–158. pmid:18154225
- 20. Makuch A, Reschke K. Playing games in promoting childhood dental health. Patient Educ Couns. 2001;43: 105–110. pmid:11311844
- 21. John BJ, Asokan S, Shankar S. Evaluation of different health education interventions among preschoolers: a randomized controlled pilot trial. J Indian Soc Pedod Prev Dent. 2013;31: 96–99. pmid:23886720
- 22. Ramseier CA, Leiggener I, Lang NP, Bagramian RA, Inglehart MR. Short-term effects of hygiene education for preschool (kindergarten) children: a clinical study. Oral Health Prev Dent. 2007;5: 19–24. pmid:17366757
- 23. Frazão P. Effectiveness of the bucco-lingual technique within a school-based supervised toothbrushing program on preventing caries: a randomized controlled trial. BMC Oral Health. 2011;11: 11. pmid:21426572
- 24. Qadri G, Alkilzy M, Franze M, Hoffmann W, Splieth C. School-based oral health education increases caries inequalities. Community Dent Health. 2018;35: 153–159. pmid:30106523
- 25. Albandar JM, Buischi YA, Mayer MP, Axelsson P. Long-term effect of two preventive programs on the incidence of plaque and gingivitis in adolescents. J Periodontol. 1994;65: 605–610. pmid:8083793
- 26. Frencken JE, Borsum-Andersson K, Makoni F, Moyana F, Mwashaenyi S, Mulder J. Effectiveness of an oral health education programme in primary schools in Zimbabwe after 3.5 years. Community Dent Oral Epidemiol. 2001;29: 253–259. pmid:11515638
- 27. Haleem A, Siddiqui MI, Khan AA. School-based strategies for oral health education of adolescents—a cluster randomized controlled trial. BMC Oral Health. 2012;12: 54. pmid:23249443
- 28. Saied-Moallemi Z, Virtanen JI, Vehkalahti MM, Tehranchi A, Murtomaa H. School-based intervention to promote preadolescents’ gingival health: a community trial. Community Dent Oral Epidemiol. 2009;37: 518–526. pmid:19694774
- 29. Haleem A, Khan MK, Sufia S, Chaudhry S, Siddiqui MI, Khan AA. The role of repetition and reinforcement in school-based oral health education-a cluster randomized controlled trial. BMC Public Health. 2016;16: 2. pmid:26728002
- 30. van Palenstein Helderman WH, Munck L, Mushendwa S, Mrema FG. Cleaning effectiveness of chewing sticks among Tanzanian schoolchildren. J Clin Periodontol. 1992;19: 460–463. pmid:1430280
- 31. Jackson RJ, Newman HN, Smart GJ, Stokes E, Hogan JI, Brown C, et al. The effects of a supervised toothbrushing programme on the caries increment of primary school children, initially aged 5–6 years. Caries Res. 2005;39: 108–115. pmid:15741722
- 32. Rosema NAM, van Palenstein Helderman WH, van der Weijden GA. Gingivitis and plaque scores of 8- to 11-year-old Burmese children following participation in a 2-year school-based toothbrushing programme. Int J Dent Hyg. 2012;10: 163–168. pmid:22540419
- 33. Çalişir H, Güneş Z, Yürük Ö. Effects of individual training of primary schoolchildren on tooth brushing skills. HealthMED. 2012;6: 505–510.
- 34. Zarod BK, Lennon MA. The effect of school dental screening on dental attendance. The results of a randomised controlled trial. Community Dent Health. 1992;9: 361–368. pmid:1486524
- 35. Tomazoni F, Vettore M V, Baker SR, Ardenghi TM. Can a School-Based Intervention Improve the Oral Health-Related Quality of Life of Brazilian Children? JDR Clin Transl Res. 2019;4: 229–238. pmid:30931715
- 36. Nammontri O, Robinson PG, Baker SR. Enhancing oral health via sense of coherence: a cluster-randomized trial. J Dent Res. 2013;92: 26–31. pmid:23018820
- 37. Bagramian RA, Graves RC, Bhat M. A combined approach to preventing dental caries in schoolchildren: caries reductions after one year. J Am Dent Assoc. 1976;93: 1014–1019. pmid:1067352
- 38. Freeman R, Gibson B, Humphris G, Leonard H, Yuan S, Whelton H. School-based health education programmes, health-learning capacity and child oral health-related quality of life. Health Educ J. 2016;75: 698–711.
- 39. Young C, Wong KY, Cheung LK. Effectiveness of educational poster on knowledge of emergency management of dental trauma—part 2: cluster randomised controlled trial for secondary school students. PLoS One. 2014;9: e101972. pmid:25093728
- 40. Pakpour AH, Yekaninejad MS, Sniehotta FF, Updegraff JA, Dombrowski SU. The effectiveness of gain-versus loss-framed health messages in improving oral health in Iranian secondary schools: a cluster-randomized controlled trial. Ann Behav Med. 2014;47: 376–387. pmid:24163187
- 41. Chandrashekar BR, Suma S, Sukhabogi JR, Manjunath BC, Kallury A. Oral health promotion among rural school children through teachers: an interventional study. Indian J Public Health. 2014;58: 235–240. pmid:25491514
- 42. Sote EO. Oral prophylactic procedures and gingival health among Nigerian school children. African Dent J. 1991;5: 15–20. pmid:1819290
- 43. Craft M, Croucher R, Dickinson J, James M, Clements M, Rodgers AI. Natural Nashers: a programme of dental health education for adolescents in schools. Int Dent J. 1984;34: 204–213. pmid:6592151
- 44. Wu L, Gao X, Lo ECM, Ho SMY, McGrath C, Wong MCM. Motivational Interviewing to Promote Oral Health in Adolescents. J Adolesc Heal. 2017;61: 378–384. pmid:28532895
- 45. Hedman E, Gabre P, Birkhed D. Dental hygienists working in schools—a two-year oral health intervention programme in Swedish secondary schools. Oral Health Prev Dent. 2015;13: 177–188. pmid:24914429
- 46. Jürgensen N, Petersen PE. Promoting oral health of children through schools—Results from a WHO global survey 2012. Community Dent Health. 2013;30: 204–218. pmid:24575523
- 47. Kwan SYL, Petersen PE, Pine CM, Borutta A. Health-promoting schools: an opportunity for oral health promotion. Bull World Heal Organ. 2005;83: 677–685. Available: https://pubmed.ncbi.nlm.nih.gov/16211159/ pmid:16211159
- 48. Khoshnevisan MH, Pakkhesal M, Jadidfard M-P, Nejad G. School-based oral health promotion: a thorough review. 2017;35: 143–149.