Dental Caries Prevalence and Burden

Dental caries - tooth decay caused by the demineralization of dental hard tissue by acids from microbial fermentation of dietary sugars - is one of the most widespread chronic conditions worldwide. This entry summarizes how its prevalence and burden are measured across populations and what global estimates show about untreated caries in particular.

Definition

Dental caries prevalence and burden refers to the population-level frequency of tooth decay and the quantified health loss it causes, typically expressed as the proportion of people affected, the amount of untreated disease, and disability-adjusted life years.

Scope

The entry covers population-level measurement of caries: how prevalence and the burden of untreated disease are estimated, the global and regional picture from systematic analyses, and the role of standardized detection systems and diet in shaping that burden. It is a reference summary of caries epidemiology, not clinical guidance on diagnosing or treating individual caries lesions.

Core questions

• How common is dental caries, and how much of it is left untreated?
• How is the burden of caries quantified at the population level?
• How does caries burden vary across regions, ages, and dentition (primary versus permanent)?
• Which standardized systems allow caries to be measured comparably across surveys?

Key concepts

• Prevalence of caries experience
• Untreated caries
• Caries in primary versus permanent dentition
• Disability-adjusted life years from caries
• ICDAS caries detection
• Common risk factor approach
• Sugar as a shared dietary risk factor

Mechanisms

Caries develops when frequent exposure of tooth surfaces to fermentable sugars allows acidogenic biofilm bacteria to produce acid that demineralizes enamel and dentine faster than saliva can remineralize it; sustained imbalance produces a cavitated lesion. Because sugar is a shared driver of caries and several other noncommunicable diseases, the common risk factor approach frames sugar reduction as an upstream lever relevant to caries burden (Sheiham & Watt, 2000). At the population level, measurement depends on standardized detection thresholds such as ICDAS, which define when a lesion is counted (Ismail et al., 2007).

Clinical relevance

Knowing how much caries exists in a population, and how much remains untreated, helps dental public health describe unmet treatment need and monitor change over time. This entry is a reference account of measured burden; it characterizes populations and is not a basis for individual diagnostic or treatment decisions.

Epidemiology

Untreated caries of permanent teeth has been identified as the single most prevalent condition in Global Burden of Disease analyses, and untreated caries of deciduous teeth is also highly common; systematic estimates show that caries affects a large share of children and adults worldwide and that the burden of untreated disease has remained substantial over recent decades (Kassebaum et al., 2015; Kassebaum et al., 2017; Peres et al., 2019).

Evidence & guidelines

Comparable measurement of caries burden relies on standardized detection criteria; the International Caries Detection and Assessment System (ICDAS) provides graded visual criteria intended to harmonize how caries is recorded across studies and surveys (Ismail et al., 2007).

History

Caries measurement evolved from early counts of decayed and missing teeth toward standardized indices and, more recently, graded detection systems such as ICDAS and comparative global burden metrics, allowing both cavitated and earlier-stage lesions to be captured and compared across populations.

Debates

At what threshold should caries be counted?

Traditional indices record caries only at the cavitated stage, whereas systems such as ICDAS also capture earlier non-cavitated lesions; the chosen threshold changes measured prevalence and complicates comparison between studies.

Key figures

• Wagner Marcenes
• Nicholas Kassebaum
• Amid Ismail
• Aubrey Sheiham

Seminal works

• kassebaum-2015
• kassebaum-2017
• peres-2019

Frequently asked questions

Is dental caries really one of the most common diseases?

Yes. Global Burden of Disease analyses have repeatedly identified untreated caries of permanent teeth as among the most prevalent conditions worldwide, affecting billions of people.

What does 'untreated caries' mean in burden estimates?

It refers to decay that has not been restored or otherwise managed; it is tracked separately because it represents unmet treatment need rather than total lifetime caries experience.