Abstract
Data sources PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials databases.
Study selection PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials databases were searched for studies published in English between January 1950 and February 2017.
Data extraction and synthesis Data were extracted independently by two reviewers and risk of bias assessed using a modified Jadad scale. Heterogeneity was evaluated using the chi-squared statistic and meta-analysis performed.
Results Three randomised trials were included, involving 681 participants; all children 10-13 years old. Two trials were conducted in the USA and one in the UK. Two studies tested school-based, daily supervised oral hygiene (including plaque staining and removal and supervised flossing) against control groups; one study tested the same intervention every two weeks against controls. Two studies measured decayed, missing or filled surfaces (DMFS) scores at three years and one trial at 29 months. Personal oral hygiene interventions failed to influence the incidence of dental caries, (DMFS = -0.11; 95% CI -0.91, 0.69: P value <0.79). Four non-randomised trials were retained to conduct sensitivity analyses.
Conclusions Personal oral hygiene interventions delivered to school children failed to show a reduction in coronal dental carious lesion incidence over three years when compared to control groups.
A Commentary on
Hujoel P P, Hujoel M L A, Kotsakis G A.
Personal oral hygiene and dental caries: A systematic review of randomised controlled trials. Gerodontology 2018; 35: 282-289. DOI: 10.1111/ger.12331. PubMed PMID: 29766564.
Commentary
Dental caries remains a highly prevalent global condition1,2 which is largely preventable, with evidence that effective long-term dental plaque control can lead to reductions in caries experience.3
Modern concepts in cariology promote the theory that the regular exposure of plaque to fermentable dietary sugars results in repeated conditions of low pH within the oral biofilm. These conditions favour the growth and metabolism of acid-tolerating bacteria while inhibiting beneficial organisms that preferentially grow at neutral pH.4 Dental caries can be considered a consequence of an ecological shift in the balance of the normally beneficial oral microbiota, driven by lifestyle factors such as diet and cleaning; these oral environment conditions, in turn, drive dysbiosis and subsequent reduction in biofilm pH,4 promoting dental hard tissue net mineral loss.5
The authors of this paper refer to two conflicting hypotheses in caries aetiology: the oral hygiene hypothesis which suggests mechanical biofilm removal from dental surfaces is preventive; and the dental defect hypothesis,6 which suggests dental carious lesions start in microscopic cracks or crevices in teeth and that biofilm removal from these crevices is ineffective. The aim of this review was to assess the effect of personal oral hygiene interventions on the incidence of dental caries as a way of resolving the conflict between these hypotheses.
The authors searched for studies published between 1950 and 2017, with the three included studies published between 1976 and 1981. None of the included studies were considered low-risk of bias for random sequence generation or allocation concealment, while participant blinding was not possible given the intervention under investigation.
A table of included studies is presented, but there are significant deficiencies which lead to uncertainty for readers when assessing the quality of these studies. Details on the recruitment of schools and participants, and on the included populations are lacking, limiting the generalisability of results. Specifics of the interventions and controls are not reported, and there is no definition of personal oral hygiene interventions provided. There is no detail on the use of fluoridated, non-fluoridated or of any toothpaste in the included studies, and no detail on adherence to the interventions. Without details on the control groups, it is left to the reader to infer what these might be. These deficiencies prevent assessment of the appropriateness of measures to prevent contamination between participants in different intervention arms. Drop-out rates of 15-39% are reported, with no detail on the differences between intervention arms.
The outcome measure decayed, missing or filled surfaces (DMFS) was extracted for each study and the standardised mean difference pooled in a random effects model. There is no detail at what diagnostic threshold caries was reported. It is recognised that the DMF index is not a perfect epidemiological tool,7 as it is unable to discriminate between advanced and initial carious lesions, and the missing component may overestimate the caries increment.
This study concludes that there is a lack of evidence to support the efficacy of personal oral hygiene in preventing or controlling coronal dental caries, and as the authors have presented only two hypotheses, they state support for the dental defect hypothesis. The included studies have shown that school-based personal oral hygiene programmes did not influence the incidence of dental caries in a population of 681 school children. It is possible that small therapeutic effects of personal oral hygiene remain undetected in statistically underpowered trials, but this would indicate that the effect was perhaps also not clinically important. It is also difficult to extrapolate the findings in school children to adults with different dental restorative status, gingival recession, saliva flow or systemic diseases.
The results of this review contrast with current concepts in cariology and attempt to question the effectiveness of biofilm removal in the absence of fluoride supplements on reducing caries experience. However, without adequate information relating to the primary studies, it is not possible to rule out deficiencies in primary study methodologies that led to the introduction of a combination of selection, performance, intervention adherence and attrition bias, making it difficult for readers to accept the study conclusions. Equally, it also fails to support the theory that brushing alone reduces carious lesion incidence.
References
Kassebaum N J, Bernabe E, Dahiya M, Bhandari B, Murray C J, Marcenes W. Global burden of untreated caries: a systematic review and metaregression. J Dent Res 2015; 94: 650-658.
Marcenes W, Kassebaum N J, Bernabé E et al. Global burden of oral conditions in 1990-2010: a systematic analysis. J Dent Res 2013; 92: 592-597.
Axelsson P, Nystrom B, Lindhe J. The long-term effect of a plaque control programme on tooth mortality, caries and periodontal disease in adults. Results after 30 years of maintenance. J Clin Periodontol 2004; 31: 749-757.
Pitts N B, Zero D T, Marsh P D et al. Dental caries. Nat Rev Dis Primers 2017; 3:17030.
Conrads G, About I. Pathophysiology of Dental Caries. Monogr Oral Sci 2018; 27: 1-10.
Mellanby M. An experimental study of the influence of diet on teeth formation. Lancet 1918; 192: 767-770.
Broadbent J M, Thomson W M. For debate: Problems with the DMF index pertinent to dental caries data analysis. Community Dent Oral Epidemiol 2005; 33: 400-409.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Innes, N., Fee, P. Is personal oral hygiene advice effective in preventing coronal dental caries?. Evid Based Dent 20, 52–53 (2019). https://doi.org/10.1038/s41432-019-0028-3
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41432-019-0028-3
This article is cited by
-
The oral microbiome in the pathophysiology of cardiovascular disease
Nature Reviews Cardiology (2023)