Introduction

Caries detection and diagnosis involves recognizing the presence of caries based on observable signs and symptoms. This process serves as the foundation for clinical decision-making regarding disease identification, preventive measures, and treatment options.¹ When developing a treatment plan, the stage and progression of dental caries determine the appropriate management approach.² In the early stages, preventive or non-restorative methods are typically recommended to halt progression and promote remineralization of affected tissues.^3,4

For moderate to severe carious lesions, minimally invasive operative treatments combined with caries control strategies are necessary.^5,6 Thus, an accurate and timely diagnosis is essential for selecting the most effective treatment plan and interventions to prevent further caries development.⁷ Additionally, in the recent decades, advancements in dental caries management have evolved alongside a growing understanding of the disease. These developments have led to ongoing discussions on the most effective strategies for both prevention and treatment. It is now evident that dentists must integrate new concepts and technologies into their approach to caries diagnosis, assessment, and management.⁸

The scientific literature points to three main reasons why caries lesion diagnosis is important:

1. To achieve the best health outcome for the patient by classifying caries lesions corresponding to the best management options for each lesion type. Lesions are currently classified in the following way:

   1. Non-cavitated lesions, also referred to as pre-cavitated lesions, early lesions, incipient lesions, superficial caries, or commonly known as "white spot" lesions, can often be managed with non-operative approaches, such as remineralization therapies (e.g., brushing with fluoridated toothpaste).⁸ (Note: It is important to refrain from using a sharp probe during a clinical examination. The application of pressure with a sharp tip can lead to permanent damage to the demineralized enamel surface, potentially converting a reversible lesion into a cavitated one. It is recommended to use a probe with a dull end and apply gentle pressure.^8,9,10

   2. Cavitated lesions, are when a hole has developed in the tooth as tissue destruction persists, which leads to surface breakdown and the formation of a micro-cavity— a localized defect in the enamel without undermining. If this discontinuity in the enamel continues to progress, eventually exposing the dentin and this then results in what is known as a "cavitated lesion" that requires restoration via surgical intervention, such as a filling after excavation of the carious tissue.¹¹

   3. These lesions are further categorized as either active or non-active (arrested) lesions:

      1. active lesions, which indicate ongoing mineral loss, and may be responsive to non-operative therapie.

      2. non-active lesions (which do not require intervention because biofilm metabolic activity is unlikely to lead to mineral loss).¹²

2. To inform the patient. The patient is the key in the management process because their cooperation is crucial in controlling the disease and slowing or reversing caries progression. Therefore, providing them with as much information as possible about the caries diagnosis is very important.²

3. To monitor the clinical course of the disease. Caries development is a dynamic process and long-term monitoring of all stages of caries lesions and recording changes in activity status or surface integrity is the only way to tell if caries is reversing or progressing. An active lesion that becomes inactive is a positive outcome, while active lesions that remain active reflect a lack of compliance or cooperation on the part of the patient, and professional intervention may be needed.²

What follows is a discussion of the different methods of caries diagnosis and highlights the close relationship between diagnosis and disease management.

Historically, clinicians primarily relied on the use of caries measurement systems that focused solely on the assessment of the presence and severity of cavitated lesions. However, as our understanding of caries has evolved, we now recognize it as a dynamic process. Non-cavitated lesions have the potential to either reverse through remineralization or progress due to demineralization, depending on individual patient conditions.

Due to the ability of early lesions to reverse through the use of preventative therapies, such as the use of fluoridated toothpastes, mouthrinses or other remineralization therapies, early detection has become increasingly important. Identifying caries at the earliest possible stage maximizes the opportunity to preserve natural tooth structure, leading to better long-term oral health outcomes.

In recent years, significant efforts have been made to develop comprehensive caries measurement systems that assess the disease across its entire continuum, starting from the earliest non-cavitated lesions. These advancements reflect a shift from merely identifying cavitated lesions to a more nuanced approach that considers the dynamic nature of caries development and progression.

The most widely used system now available is the International Caries Detection and Assessment System (ICDAS), an evidence based integrated system that includes all of the best understanding of caries to provide a standardized method for monitoring both the initiation and progression of caries across this continuum. Later in this course, we will explore the International Caries Classification and Management System (ICCMS), which is closely linked to ICDAS. While ICDAS primarily focuses on identifying and classifying caries, ICCMS builds upon this by offering a structured, risk-based approach to patient-centered caries management.¹³