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. 2020 Mar 24;15(3):e0230639.
doi: 10.1371/journal.pone.0230639. eCollection 2020.

Implementation and Impact of a Dental Preventive Intervention Conducted Within a Health Promotion Program on Health Inequalities: A Retrospective Study

Free PMC article

Implementation and Impact of a Dental Preventive Intervention Conducted Within a Health Promotion Program on Health Inequalities: A Retrospective Study

Hélène Pichot et al. PLoS One. .
Free PMC article


Background: The objective of this retrospective survey was to evaluate after one year, the conditions and impacts of a dental sealant intervention conducted in New Caledonia, within a health promotion program. A greater or at least equivalent quality and impact of the intervention was expected for children living in socially deprived regions with the greatest health needs.

Methods: The study population was the schoolchildren, aged 6 years in 2016, who benefited from the dental sealant program (n = 2532). The study sample was randomly selected in 2017 from that population (n = 550). The children's dental status was evaluated at school in 2017 and compared with that recorded in 2016 during the sealant intervention allowing the calculation of the retention rates and one-year carious increment on first permanent molars. Socio-demographic variables (gender, public/private school) and conditions of sealant placement (school/dental office, presence of a dental assistant) were recorded. The carious increment was explained using a mixed multiple random-effects regression. A mediation analysis was conducted to assess the respective contributions of the retention rates and the region of origin on caries increment.

Results: The participation rate was very high (89%) and on average, children had 83% of their dental sealants present after one year, 31% fully and 52% partially present. Caries increment varied depending on the sealant retention rate as well as on the region (North, South, Islands). The mediation analysis showed that living in a deprived area (The Islands) was a strong determinant for high caries increment particularly when the retention rates were low.

Conclusions: This study showed a high participation rate and acceptable effectiveness as measured with the one-year retention rates, for a fissure sealant intervention conducted in real-life conditions and integrated in a large health promotion program. Nevertheless, the intervention was not effective enough to totally balance the influence of health determinants, especially in socially deprived sectors characterized by greater dental needs.

Conflict of interest statement

The authors have declared that no competing interests exist.


Fig 1
Fig 1. Complete and global retention rates and caries increment (ΔDT1st molars) depending on the region and setting of sealant placement.
Fig 2
Fig 2. Mediation analysis of caries increment (Model B).
Tested mediator: Global retention rate. Independent variable: Region (Model B: the Islands compared to the North and South). Baseline risk co-variates: gender, type of school (private vs public), dental status in 2016 (number of first molars and % with carious lesions), conditions of sealant placement (school vs dental office, with or without dental assistant), examiner effect (as random effect). Step 1: The first step in our mediational analysis was the finding that belonging to the Islands region as compared to the North and South regions had a measurable impact on caries increment after accounting for baseline risk covariates. Step 2: Second, we checked if the retention rate (mediator) was related with the region, after accounting for baseline risk covariates. Step 3: Finally, a multilinear regression (mixed model) calculated the influence of the region on the tested mediator (retention rate). Subsequently, we jointly calculated the influence of the mediator and the direct effect of the independent variable on caries increment after accounting for baseline risk covariates. This last step shows that retention rate partially mediates [38%. P = for the average causal mediation effect (ACME)] the original effect of the region on caries increment and consequently remains directly associated with caries increment in an independent manner. The mediator (retention rate) and the main independent variable (Region) are assessed as binary variables.

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    1. Global Burden of Disease Study 2013 Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2015;386: 743–800. 10.1016/S0140-6736(15)60692-4 - DOI - PMC - PubMed
    1. Marmot MG. Understanding social inequalities in health. Perspect Biol Med. 2003;46: S9–23. - PubMed
    1. Lorenc T, Petticrew M, Welch V, Tugwell P. What types of interventions generate inequalities? Evidence from systematic reviews. J Epidemiol Community Health. 2013;67: 190–193. 10.1136/jech-2012-201257 - DOI - PubMed
    1. de Silva AM, Hegde S, Akudo Nwagbara B, Calache H, Gussy MG, Nasser M, et al. Community-based population-level interventions for promoting child oral health. Cochrane Database Syst Rev. 2016;9: CD009837 10.1002/14651858.CD009837.pub2 - DOI - PMC - PubMed
    1. INSEE Première. Recensement de la population en Nouvelle-Calédonie en 2014. 2015 Nov. Report No.: 1572. Available:

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The author(s) received no specific funding for this work