Root caries risk predictors

shutterstock_34500700 - caries sign

With many countries of the world showing an increase in the numbers of older adults. This increase is also linked with an increase in the number of natural teeth in this age group and as a result we are seeing an increase in the root caries with prevalence rates ranging from 9.8 – 71% being reported in some groups. Studies have suggested a number of possible risk factors which would assist in the management of this preventable disease.

The aim of this review was to identify the risk predictors of root caries and to describe their relationship with the incidence and increment of root caries.


Searches were conducted in the Medline/PubMed, Embase, and Scopus databases without restriction on language. Longitudinal observational studies reporting on at least one risk factor for root caries were considered. Two reviewers independently screened and selected the studies. Study quality was assessed using the Newcastle-Ottawa Scale for cohort studies. Risk predictors of root caries identified in the included studies were placed under six categories, namely:  socio-demographic background; general health conditions; general behaviours; fluoride exposure; oral health related habits; and oral health condition (e.g. clinical parameters, oral microbiota and salivary parameters). A narrative summary was presented.


  • 19 studies reporting on 16 cohorts were included.
  • 4 studies were considered to be of high quality, 13 moderate quality and 2 low quality.
  • The studies were from, Australia, Brazil, China, Finland, Mexico, Sweden and the U.S.A.
  • 7 studies used random sampling, 8 non-probability sampling with 1 study not specifying their method.
  • 1 study used the ICDAS II root caries diagnostic criteria, 3 WHO criteria, 10 visual-tactile examination with a reference cited while 2 studies did not specify the criteria.
  • 3 studies reported both the incidence and the increment of root surface caries while 6 only reported the incidence and 7 studies increment.
  • 7 studies only reported on DF-root (decayed and filled root), 4 studies on D-root (untreated active root caries). Only with 5 studies reported on both DF-root and D-root.
  • Positive correlations between new root caries and age, baseline root caries experience, gingival recession and use of tobacco were reported.
  • Negative correlations were found for socio-economic status, good oral hygiene and use of fluorides.
  • Mixed findings were detected for the association between new root caries and the number of natural teeth.
  No of studies reporting
Socio-demographic factors 10
General health conditions 6
General behaviours 7
Fluoride exposure 1
Oral health related habits 3
Oral health condition 12


The authors concluded: –

This systematic review discovered a number of root caries risk predictors in different categories. People who are older, in lower socio-economic status or tobacco users, and those with more root caries experience, gingival recession and poor oral hygiene have higher risk of developing new root caries.


This review has a review protocol which is available on the PROSPERO database and a good range of databases was searches with no language limits. Only longitudinal studies with a follow up rat of 50% or more were included. However only 4 of the included studies were considered to be of high quality so the findings should be viewed cautiously. Heterogeneity in the measurements of the various factors also meant that meta-analysis of the data was not conducted. Only studies published since 1990 were included in the review which means that the findings should be  relevant to the current position.

This group have also published another view on this topic (Zhang, Sardana, Wong et al; 2019) which included any observational study with more than 100 participants with many of the 44 studies being cross-sectional.  The future use of common outcomes for reporting studies in this area would be beneficial.


Primary Paper

Zhang J, Leung KCM, Sardana D, Wong MCM, Lo ECM. Risk predictors of dental root caries: a systematic review. J Dent. 2019 Jul 10. pii:S0300-5712(19)30148-4. doi: 10.1016/j.jdent.2019.07.004. [Epub ahead of print]Review. PubMed PMID: 31301318.

Review protocol on PROSPERO

Other references

Zhang J, Sardana D, Wong MCM, Leung KCM, Lo ECM. Factors Associated with Dental Root Caries: A Systematic Review. JDR Clin Trans Res. 2019 May 30:2380084419849045. doi: 10.1177/2380084419849045. [Epub ahead of print] PubMed  PMID: 31145661

Review protocol in PROSPERO

Dental Elf – 22nd Aug 2018

Root Caries: Incidence and increment


Dental Elf – Root Caries Blogs





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