Caries risk assessment (CRA): a review of the evidence

The concept of caries risk assessment (CRA) is a well acknowledged tool (Usha, 2018). This tool revolves behind that the dental caries is a disease (Seetha et al., 2020). With the evidence from the science of cariology, CRA became the main point of interest in management of that disease (Usha, 2018). Mainly what is taught in dentistry is still overshadowed by the technical and technological advances in restorative dentistry (Usha, 2018), that is mainly concerned with the restoration of the dental carious lesion rather than patient service and prevention (Usha, 2018). Prevention is one of the scopes that CRA focuses on (Seetha et al., 2020).

This paper is going to attempt to review CRA various aspects with the help of the recent literature and evidence.

The definition of risk is the probability of a negative and undesired event occurrence (Twetman & Fontana, 2009). It can also be defined as the identification and assessment of the contributing factors accountable to a disease, risk level prediction, identifying potential ways to counteract the onset and advancement of a disease (Kumar & Agrawal, 2013).

CRA is concerned with the means of identifying the risk for a patient to establish new carious lesion, including enamel and dentin (Incidence) (Twetman et al., 2013). In addition, it assesses the risk of further progression of the dental lesion in size and activity (Progression) (Fontana & Zero, 2006).

Background of CRA

Dental caries is a local destruction of the organic and non-organic tissue of the tooth by the alteration of the pH-balance on the surface of the tooth to a more acidic level (Selwitz, 2007). This is caused by the fermentation of carbohydrates by the acidogenic bacteria of the mouth (Selwitz, 2007). This disease is dynamic in nature, where a constant process of interaction between the tooth-biofilm interface (Beck, 1998). Two factors affect the equilibrium on the surface of the tooth these include but not limited to: (1) shift in the number of the microbial load (organic) in the biofilm and maturation of the microorganisms (Enerbäck et al., 2020). (2) alteration in the (inorganic) mineral content which fluctuates between demineralization and remineralization (Enerbäck et al., 2020).

This mineral content homeostasis is between the tooth surface and the saliva contents (Jørgensen & Twetman, 2020).

If the frequency of ingested fermentable carbohydrate increases the probability of developing a cariogenic biofilm on the tooth surface increase (Jørgensen & Twetman, 2020). In addition, the acidic pH of the biofilm persists and results in demineralization (Enerbäck et al., 2020). The initial non cavitated lesion becomes an established cavitated one (Selwitz, 2007). Furthermore, the salivary flow responsible for the buffering action can neutralize the acidity of the biofilm and reduce the activity of the carious lesion (Jørgensen & Twetman, 2020).

If the frequency of ingested fermentable. This is identified as remineralization action of the saliva (Jørgensen & Twetman, 2020).

These factors directly influence the incidence of the disease and are combined called the determinants of the disease or the risk factors (Usha, 2018). Other contributing factors that indirectly causative and can affect the disease process are called the confounders. (Fejerskov & Manji, 1990). Some of the confounders to dental caries suggested are socioeconomic status, oral health awareness, life-style habits and education (Usha, 2018). These factors can contribute to variations in the CRA between a patient with the same risk factors but different confounders (Usha, 2018).

The figure below characterizes the risk factor and confounder variables in dental caries disease (Loveren & Broukal, 2012). As a multifactorial disease in nature the model below shows different variables with their significance to the disease (Loveren & Broukal, 2012).

In the diagram above the individuals who are at risk are recognized and factors that are directly or indirectly contributing to dental caries are thus, removed and eliminated (Loveren & Broukal, 2012). Criteria for preventive measures are then produced to decrease the risk (Loveren & Broukal, 2012).

Dental caries as a multifactorial based disease it is also linked to lifestyle of the individual and improvements in the dental attitude of the patient can strongly influence its process and progress (Frencken et al., 2012).

Therefore, it is not sufficient for the dentist to only “drill and fill”; dental caries should be controlled and monitored throughout the patient life, with preventive techniques and modifications in the lifestyle which include the confounding factors (Anderson et al., 1993).

Such control requires a longitudinal follow-up through periodic recalls (Anderson et al., 1993).

Below are bullet points that summarizes the main objectives of CRA (Usha, 2018).

• Identification of the risk factors, combination of factors, that are causative of dental disease.
• Identification of the confounding factors that affect the risk status of the individual and the progression of the disease.
• Plan a patient-tailored preventive strategy based on the risk factors and confounders.
• Plan an operative or non-operative treatment plan that depend on the risk, activity, and prognosis of the disease.
• Use of other diagnostic modalities to further identify the disease.
• To make a decision regarding the frequency of recall and follow-up appointments.

(Usha, 2018)

How to perform CRA?

An accurate caries assessment tool has to include questionnaire regarding one or multiple variables contributing to the disease, such as: social, environmental, clinical and microbiological (Beck et al., 1988). Numerous professional organizations and universities have created multiple CRA tools (Ismail et al., 2015). Most of them seem to include the major risk and confounding factors (Ismail et al., 2015). However, diverge mainly to the local population characteristics to the organizations/universities such as the caries prevalence and ages of the patient (Ismail et al., 2015).

These tools can be generalized using important risk factors and confounders which are collected in a checklist and the risk is qualitatively assessed (Usha, 2018). Currently, the most researched reasoning-based risk assessment tools available are CAMBRA (caries management by risk assessment) (Featherstone et al., 2007). This tool is recommended by the American Association of Dentistry (ADA, 2011), and American Academy of Pediatric Dentistry (AAPD, 2019).

Recently developed, the International Caries Control and Management System (ICCMS) that is based on CAMBRA (Pitts et al., 2014). Another tool such as the Cariogram which is a familiar computerized program, that assesses the combination of risk factors in a subjective manner and plan the possibility of prevention of new dental caries in percentage form (Bratthall & Petersson, 2005).

The ideal requirement of a CRA, as explained by Stamm et al. (1988) is that “To be useful, a working caries prediction model should produce a sensitivity level of 0.75 or higher and specificity level of at least 0.85 or higher.”

The current caries assessment tools can differ in the quantity of data collected (Usha, 2018).

For instance, in different CRA tools, it is apparent that risk factors are not disregarded but rather been summarized under wide-ranging headings (Usha, 2018), such as in the CAMBRA tool which possess 25 factors for fluoride exposure enlisted, whereas Cariogram program elicits only 9 factors. (Usha, 2018).

Figure 2 shows that fluoride exposure factor in Cariogram is equivalent to seven questions that need to be individually assessed under the same heading in CAMBRA. (Usha, 2018).

Therefore, it also becomes obvious that the role of the dental practitioner in CRA is of utmost importance, irrespective of the type of tool being used (Usha, 2018). In addition, the knowledge, skill of interpretation of the collected data and categorizing the risk factors plays a critical role toward the future treatment of the patient (Twetman & Fontana, 2009).

Care pathways are documents developed to help in the clinical diagnosis and treatment planning (AAPD, 2019). It offers a specific criterion for the clinician and lead to recommended courses of action (Rotter et al., 2012). These pathways were developed based on peer-reviewed literature and current judgement of experts combined with clinical experience of practitioners (AAPD, 2019). These care pathways were first introduced by Ramos-Gomez (2011) for caries management in children aged 0-2 and 3-5 years old. It is well known now that restorative dentistry alone is not sufficient to stop the disease process (AAPD, 2019). That’s why, modern criteria for the management of the dental disease in minimal intervention dentistry is more encouraged. Which includes early diagnosis, identification of the caries risk of the patient and the progression of the disease in this particular patient. (AAPD, 2019). Tables below identify the specific risk levels with the age and compliance to the preventive strategies. (AAPD, 2019). Yielding such pathways can help in greater success rates of treatment with more efficient use of resources and less complications (AAPD, 2019).

Other approaches to the assessment and treatment of dental caries will emerge with time and, with evidence of effectiveness, may be included in future guidelines on caries-risk assessment and care pathways (AAPD, 2019).

Conclusion

Caries risk assessment tools risk for such dynamic disease is very thought-provoking process because it only provides a cross sectional idea for the disease and level of risk can change in time. However, it provides a very comprehensive idea regarding the preventive actions that the patient can undergo towards improving their dental attitude into a positive one.

Clinicians are also more encouraged now than ever before with the recent knowledge to practice preventive and minimal intervention dentistry.