Clinical risk 1: Caries

Louis Mackenzie, Head Dental Officer at Denplan, provides the first in a series of articles designed to help clinicians optimise disease risk assessments in general practice.

Despite decades of declining incidence, caries remains the world’s most common disease, with approximately 44% of the global population having untreated caries in their permanent and/or deciduous dentition.¹

As a multifactorial disease, the risk of carious tooth damage depends on each patient’s unique balance of disease indicators and pathogenic and protective risk factors.^1,2,3

Caries risk is defined as the likelihood of a person having new or extended decay in the future² and analysis of risk/susceptibility is a cornerstone of contemporary preventive dentistry.¹

Evidence from worldwide studies demonstrates that categorising patient by caries risk (e.g. low-, medium/moderate- and high-risk) offers a range of significant advantages.^1,2,3

These benefits include informing patient recall intervals and setting screening frequencies for bitewing radiographs.⁴

It is acknowledged that selection of recall intervals is a difficult, multifaceted decision that requires a combination of expert clinical judgement and application of scientific evidence relevant to each patient’s oral and general health.³ While all dentate patients are at risk from caries, susceptibility varies between individuals.¹

Risk assessment systems

Though mandated by all professional bodies and regulators, 30-40% of clinicians do not carry out any formal risk assessment for their child or adult patients.¹

Currently there is no method/tool that can predict caries with perfect accuracy. Systems that consider a range of risk factors (multivariate models) perform better than single risk factors and reported accuracy is in the range of 65-85%.¹

Prediction in pre-school and school children is more accurate than in adults, where the presence of existing restorations and exposed root dentine further reduces accuracy.¹

The literature is clear that the single most powerful risk factor in caries prediction for all age groups is previous caries experience.¹ This and level of oral hygiene are the variables most commonly used in general practice.¹

Restorative history and plaque control level form the foundation of the Denplan Care Oral Health Assessment (Categories A, B, C, D & E) and Denplan’s pioneering oral health score (OHS©) (Burke & Wilson 1995), which includes a tooth health assessment of scored out of 24. 

Objective current oral health measurements from OHS© and Denplan Care scores may then be used to inform future risk calculations.

Ideal risk assessment systems should be quick, simple, inexpensive, reliable, and easy for patients and clinicians to understand.¹ While methods that rely on checklists or computer-based algorithms may not improve accuracy, their routine use improves consistency, transparency and patient motivation.¹

While there is no international consensus or definition of risk categories and there is insufficient evidence to allow numerical weighting of individual risk and protective factors,¹ the College of General Dental Dentistry (CGDent) provides a useful caries risk assessment guide designed to help identify pathogenic and protective factors for high- and low-risk patients. Those that do not fit clearly into either high- or low-risk may be categorised as moderate/medium caries risk.⁴

Caries Management by Risk Assessment (CAMBRA)

CAMBRA is an internationally recognised concept that provides clinicians with a scientific, evidence-based approach designed to help reduce high- and medium-risk patients to low-risk and enable implementation of patient specific protocols that can arrest of even reverse the caries process.² CAMBRA’s risk-based concept aims to:

• Assess the risk of future carious lesions
• Identify and reduce pathological factors
• Enhance protective factors
• Promote minimally invasive restorative care

Risk assessment cautions

While the benefits of caries risk assessments outweigh the disadvantages, negative aspects must not be ignored.¹ They include:

• Misclassification leading to suboptimal care
• Challenges in caries detection and diagnosing lesion activity (The international caries detection and assessment system {ICDAS} is recommended)¹
• Challenges in diagnosing secondary caries
• Challenges in radiographic interpretation
• Potential stigmatisation/demoralisation of patients labelled as ‘high-risk’
• Potential loss of patient confidence, feelings of frustration/hopelessness, tendency to give up
• Assignment of risk categories is not always followed by appropriate patient-focused preventive actions

Additionally, it is recognised that despite careful caries risk categorisation, low-risk patients are the most likely to access preventive care and patients with the highest need are least likely to attend for treatment and underutilise preventive measures.¹ This is known as the inverse care law and is an unfortunate feature of healthcare systems worldwide. 

Caries and systemic disease risk

Finally, and importantly, the complex network of biological, genetic, behavioural, socio-economic, and lifestyle-related risk factors for dental caries are identical to those for other common non-communicable diseases and conditions such as diabetes, heart disease and obesity.¹ Therefore, by reducing a patient’s risk of dental caries there is the potential to significantly benefit their general health too. 

References

1. Chapple ILC, Papapanou PN, Twetman S, Banerjee A. Risk assessment in oral health. A concise guide for clinical application. 2020, Springer nature. eBook. ISBN 978-3-030-38647-4
2. Rechmann P, Kinsel R, Featherstone JDB. Integrating caries management by risk assessment (CAMBRA) and prevention strategies into the contemporary dental practice. Compend Contin Educ Dent. Volume 39(4): 226-233
3. Dental checks: intervals between oral health reviews. 2004; www.nice.org.uk/guidance.
4. Clinical examination and record keeping. Good practice guidelines. 2016; cgdent.uk