Study Guide on Caries Interpretation

Interpretation of Caries

  • Course Information
    • Course Code: DEHY 123
    • Instructor: Lindsey Farris, RDH, BSDH, MA

Introduction

  • Radiographic Interpretation
    • Importance in treating patients.
    • Dental Hygienists can interpret radiographs.
    • ONLY dentists can diagnose based on these interpretations.

Vocabulary

  • Interpret: The act of explaining.
  • Interpretation: An explanation.
  • Radiographic Interpretation: An explanation about what is viewed on a dental radiograph.
  • Diagnosis: The identification of a disease by examination or analysis, involving the use of all forms of information available.

Qualifications to Interpret

  • Only members of the dental team with proper training may interpret radiographs.
  • Individuals who can interpret include:
    • DDS (Doctor of Dental Surgery)
    • RDH (Registered Dental Hygienist)
  • Dental Assistants: Must have radiographic training in interpretation to qualify for this task.

Protocol to Read Radiographs

  • Optimal Conditions:
    • Room should have good lighting.
    • Radiographs mounted in order on the screen for clarity.
    • Computer screen settings should be adjusted for optimal viewing within the software.
    • Patient should be present to confirm findings during interpretation.

Patient Education

  • Educating patients on the significance of normal versus diseased states:
    • Show patient radiographs indicating normal conditions.
    • Present examples of radiographs showing disease.
    • Helps the patient understand the importance of radiographs and the aspects of treatment needed.

Caries

  • Definition: Loss of tooth density, either radiopaque or radiolucent.
  • Types of radiographs to use in caries detection:
    • Bite-wing radiographs
    • Periapical (PA) radiograph with paralleling technique
  • Correct Horizontal Angulation: Essential for open contacts and accurate interpretation.

Types and Descriptions of Caries

Types of Decay

  • Occlusal (Classifications exist)
  • Buccal and Lingual
  • Root Surface
  • Recurrent (Secondary)
  • Rampant
  • Interproximal (Classifications exist)

Interproximal Caries

  • Location: At or just apical to the contact point.
  • Appearance:
    • Point of a triangle shape approaching the dentino-enamel junction (DEJ).
    • Spreads at DEJ into dentin creating another triangle with the base at DEJ and apex at the pulp chamber.

Interproximal Classification According to Depth into Hard Tissue

  • Incipient:

    • Class: < half of enamel.
    • Extends less than halfway through enamel.
    • Earliest stage that can be viewed, classified as Class I (enamel only).

  • Moderate:

    • Class II
    • Extends more than halfway through enamel but does not involve the DEJ yet.

![](Figure 33-10) A moderate carious lesion, extending more than halfway through enamel but not involving DEJ.

  • Advanced:
    • Class III
    • Extends to or through the DEJ, but does not extend more than half the distance toward the pulp.

![](Figure 33-12) An advanced carious lesion, extending through enamel and to or through DEJ but not more than half toward pulp.

  • Severe:
    • Class IV
    • Extends more than halfway to pulp.

![](Figure 33-14) A severe carious lesion, which extends through enamel and dentin more than half the distance to pulp chamber.

Types of Occlusal Caries

  • Incipient Occlusal Caries:

    • Often not effective in radiographic identification.
    • Requires clinical examination to identify.

  • Moderate Occlusal Caries:

    • Appearance: Thin radiolucent line under enamel.
    • Extends into dentin but shows little change in enamel.

![](Figure 33-16) A moderate occlusal carious lesion.

  • Severe Occlusal Caries:
    • Extends into dentin, appearing as a large radiolucency and is clinically apparent with cavitation.

![](Figure 33-18) Severe occlusal caries extending into dentin.

Buccal and Lingual Caries

  • Detection Challenges:
    • Difficult to observe radiographically.
    • Best detected through clinical examination.
  • Radiographic Appearance: Small, circular radiolucencies.

![](Figure 33-20) Buccal or lingual caries seen as round radiolucency on molars.

Root Surface Caries

  • Location: Just below the Cement-Enamel Junction (CEJ).
  • Characteristics:
    • No enamel present.
    • Must have an exposed root surface.
    • Lesions appear cupped-out or crater-shaped below CEJ.
    • Early lesions are difficult to see radiographically.

![](Figure 33-22) Root caries involving only cementum and dentin.

Recurrent or Secondary Caries

  • Location: Adjacent to preexisting restorations.
  • Appearance: Radiolucent just below or under restorations, especially beneath interproximal margins.

Rampant Caries

  • Characteristics:
    • Caries that are growing or spreading without being stopped.
    • Advanced and severe lesions affecting many teeth.
  • Common Causes:
    • Poor diet, substance abuse in children.
    • Adults with decreased saliva or xerostomia.

Conclusion

  • The detailed understanding of various types of caries is essential for proper diagnosis and treatment planning in dental hygiene.
  • Further exploration and application of this knowledge can lead to better patient outcomes and education in dental health practices.