Methods
Criteria for considering studies for this review are listed below:
Type of Studies
Clinical studies of randomized controlled trials, controlled trial and longitudinal observation (prospective or retrospective study) with a minimum period of 6 months were included.
Type of Participants
Children aged 6 or below who had at least one dentin carious lesion in the primary dentition at the start of the study were considered for inclusion in this review.
Type of Interventions and Outcomes
Various non-surgical intervention methods such as fluoride agents (toothpaste, mouthrinse, gel, varnish, solution), dental sealant, resin infiltrant, chlorhexidine (CHX), xylitol, CPP-APC, ozone and oral health education were included.
The primary outcomes of the included studies were caries arrest, progression or regression. There could be comparisons of outcomes of different non-surgical approaches or comparisons of outcomes of non-surgical and surgical approaches. The treatment could be performed by dentists or dental auxiliaries. The location of treatment could be in any place such as in kindergarten, hospital or dental clinic.
Exclusion Criteria for Considering Studies for This Review
A paper was excluded if it was in one or more of the following categories:
incomplete description of sample selection and outcomes or poor study design;
early reports of studies, in-vitro or animals studies, narrative reviews or systematic reviews.
Where doubt existed over the exclusion of a study based on the title or abstract, full paper was retrieved.
Search Strategy
Identification of studies to be considered for inclusion was based on a systematic search on the common electronic databases such as Pubmed, Cochrane collaboration and EMBASE. The search was restricted to reports written in English published from 1947 to June 2014. Reports in the gray literature such as dissertations, theses, unpublished studies, product reports were not included. Inclusion and exclusion criteria were applied by examining the title and abstracts. The identified studies were independently reviewed by two reviewers for eligibility.
The keywords and MeSH terms were combined using four main concepts:
dental caries [MeSH Term] OR tooth demineralization [MeSH Term]
primary dentition [MeSH Term] OR "deciduous teeth" OR "deciduous tooth" OR "milk teeth" OR "milk tooth" OR "primary teeth" OR "primary tooth" OR child [MeSH Term]
fluorides [MeSH Term] OR pit and fissure sealants [MeSH Term] OR xylitol [MeSH Term] OR chlorhexidine [MeSH Term] OR "casein phosphopeptide-amorphous calcium phosphate" [Supplementary Concept] OR ozone [MeSH Term] OR cariostatic agents [MeSH Terms] OR "resin infiltration"
"progress*" OR "arrest*" OR "caries arrest" OR "caries progression" OR "caries control".
Since papers on the sole use of silver compounds, such as silver nitrate, without combination with fluorides would not be captured by the search using the MeSH term "fluorides", an additional search using a combination of the following MeSH terms, "silver compounds" AND "dental caries" AND "primary teeth", was carried out (last search on 29 January 2015).
Assessment Criteria
Assessment of risk of bias in the included studies was conducted by using the Cochrane risk of bias assessment tool. Seven domains were assessed for each included study: sequence generation, allocation concealment, masking of participants and personnel, masking of outcome assessment, incomplete outcome data, selective outcome reporting and other bias. Within each domain, a judgement of 'low', 'high' or 'unclear' risk of bias was made. An overall risk of bias was also made as follows:
low risk of bias (plausible bias unlikely to seriously alter the results)
unclear risk of bias where one or more of the domains were assessed as unclear
high risk of bias (plausible bias that weaken confidence in the results) where one or more domains were assessed at high risk of bias.
The studies were graded as good, fair or poor based on the ADA's criteria after assessment of their quality using the following criteria reported in the ADA Clinical Recommendations Handbook:
initial assembly of comparable groups
consideration of potential confounders with either restriction or measurement for adjustment in the analysis; consideration of inception cohorts
maintenance of comparable groups (includes attrition, cross-over, adherence, contamination)
important differential loss to follow-up or overall high loss to follow-up
measurements: equal, reliable, and valid (includes masking of outcome assessment)
clear definition of interventions
all important outcomes considered
analysis: adjustment for potential confounders for cohort studies, or intention to treat analysis for RCTs.
Data extraction
The indentified papers were reviewed independently by two investigators who were not involved in any of the included studies. The extracted information was compared and reporting was decided by consensus. If in doubt, a senior investigator was consulted. The primary summary measure for reporting in this review was the success rates of the various treatments. Regarding the treatment effect, the number needed to treat (NNT) was the average number of active caries surfaces that needed to be treated for one to benefit, i.e. become arrested, compared with the control. NNT was calculated from the original data according to the following formula: