Quality Assurance in Dental Radiography

Quality Assurance in the Dental Office

Learning Objectives

  • List tests used to check the strength of developer and fixer solutions.

  • Discuss testing methodologies for safe lighting and detection of light leaks.

  • Define key terms:

    • Normalizing device: A tool for monitoring developer strength and film density.

    • Quality administration: Overseeing quality assurance practices in a dental setting.

    • Quality assurance: Procedures ensuring high-quality diagnostic radiographs.

    • Control tests: Assessments of equipment and processing efficiency.

    • Reference radiograph: A benchmark radiograph processed under ideal conditions.

    • Stepwedge: A device used to evaluate film sensitivity.

  • Recognize quality administrative procedures.

  • Define Safety Code 30: Guidelines for radiation safety and quality assurance in dental practices.

Understanding Quality Assurance

  • Quality assurance program: A structured set of procedures aimed at ensuring high-quality diagnostic radiographs.

  • Importance of knowledge in Quality Assurance: Dental radiographers must understand and implement the office's quality assurance program.

Equipment Monitoring and Maintenance

  • All dental x-ray machines must be inspected regularly to ensure performance standards are met.

  • Machines should be calibrated at scheduled intervals by qualified technicians to guarantee accuracy during x-ray procedures.

Film Processing and Storage

  • Film appearance: Fresh film should appear clear with a slight blue tint. Fogged film indicates expiry or improper storage.

  • Check intensifying screens for cleanliness and examine cassettes for wear or light leaks.

  • Film-Screen Contact Test: Conduct tests to ensure good film-screen contact; uniform density on the film indicates adequate contact.

Darkroom Safety and Testing

  • Darkroom conditions: Check for light-tightness every six months. Visible light leaks must be corrected to prevent film exposure.

  • Safelighting Test (Coin Test):

    1. Place a coin on unexposed film in a darkroom, allowing exposure to the safelight for 3-4 minutes.

    2. If no image of the coin appears on the developed film, safelighting is adequate.

    3. A visible image indicates a need for corrections or changes to safelight filters.

Processing Solutions

  • Monitor the performance of the automatic processor:

    • Unexposed film should be clear and dry.

    • Exposed film should be black and dry.

  • Fixer solution strength:

    • Weak fixer prolongs the time for film to clear; should clear within 3-4 minutes.

    • If it does not, the fixer solution needs replacement.

Utilizing Control Tests

  • Reference Radiograph: Used as a daily comparison standard. If densities match, developer strength is adequate; discrepancies indicate weakness or over-concentration in developer solutions.

  • Stepwedge Radiograph: Demonstrates differences in x-ray absorption; useful for identifying variations in developer strength. Changes greater than 2 steps from the standard indicate a need for solution changes.

Quality Administration Procedures

  • Responsibilities: Dentist oversees the quality assurance plan, ensuring adherence to safety and processing standards.

  • Components of Quality Administration:

    • Clear descriptions of plans and assigned roles.

    • Scheduled monitoring and maintenance tasks.

    • Log of quality control test results.

    • Periodic evaluations and revisions of protocols.

    • Ongoing staff training and education on quality assurance practices.

Compliance with Safety Code 30

  • Safety Code 30 outlines:

    • Implementation of a Quality Assurance Program.

    • Procedures aimed at reducing radiation exposure to staff and patients.

    • Proper handling and processing of films.

    • Facility requirements ensuring safety standards.


These notes summarize the essential components and procedures associated with quality assurance in the dental office, crucial for ensuring safe, high-quality imaging and radiographic diagnostics.