DANB CDA key terms

A radiation protection principle meaning doses should be kept As Low As Reasonably Achievable, balancing patient benefit against exposure. It guides technique selection, film speed, and shielding choices in dental radiography.

Restricting the x-ray beam with a metal tube or diaphragm so only the area of interest is exposed. Proper rectangular collimation reduces patient dose and improves image contrast by limiting scatter.

The intensity of radiation decreases with the square of the distance from the source. Doubling the distance from the tube head cuts exposure to roughly one quarter at that point.

X-rays deflected from their original path when they strike matter such as the patient's tissues. Scatter is the main source of occupational exposure, so barriers and distance matter.

Shielding garments worn by the patient during exposure to absorb scattered radiation before it reaches radiosensitive tissues. The thyroid collar is especially important for children and pregnant patients.

Maximum permitted radiation exposure for workers, expressed as effective dose per year and monitored with a personal dosimeter. Limits are far below levels known to cause harm and are cumulative over a lifetime.

A badge worn at collar level outside protective clothing that records cumulative radiation dose. It is read periodically to confirm the worker stays within occupational limits.

An image showing the crown and root of a tooth plus surrounding bone. It is used to detect caries, periapical pathology, and bone loss, and requires the receptor to be parallel to the tooth.

An image capturing the crowns of upper and lower teeth plus crestal bone on one receptor. It is the standard view for interproximal caries and bone level assessment.

An intraoral exposure method in which the central ray is aimed perpendicular to a line bisecting the angle between tooth and receptor. It compensates for receptor distortion but magnifies the image slightly.

The center of the x-ray beam, aimed through the contact area of the teeth being imaged. Correct angulation of the central ray prevents elongation, foreshortening, and overlap on the image.

Infection control practices applied to every patient regardless of known health status, treating all blood and body fluids as potentially infectious. They include hand hygiene, gloves, and barrier protection.

Barriers worn to prevent contact with bloodborne pathogens, including gloves, masks, protective eyewear, and gowns. PPE is removed in a sequence that avoids contaminating skin or clothing.

Cleaning hands with soap and water or an alcohol-based rub at defined moments such as before gloving and after glove removal. It is the single most effective way to break the chain of infection.

The sequence of conditions required for infection to spread: a pathogen, a reservoir, a portal of exit, a mode of transmission, a portal of entry, and a susceptible host. Breaking any link prevents transmission.

A process that destroys all microorganisms, including bacterial spores, on instruments. In dentistry it is typically achieved with steam autoclave, dry heat, or unsaturated chemical vapor under monitored conditions.

Using chemicals to reduce the number of pathogens on surfaces or items that cannot withstand sterilization. It does not reliably destroy spores, so it is not a substitute for sterilizing critical instruments.

Testing a sterilizer with spore-containing indicators processed in a normal cycle, then incubated to confirm the spores were killed. It is the most reliable check that sterilization actually occurred.

Disposable plastic film placed over surfaces such as light handles and control panels before a procedure, then removed and discarded. Barriers reduce the need for chemical disinfection between patients.

An item that penetrates soft tissue or contacts bone, such as scalers, surgical burs, and forceps. Critical items must be sterilized after each use because they can introduce pathogens directly into tissue.

An item that contacts intact mucous membranes but does not penetrate tissue, such as mouth mirrors and impression trays. These require sterilization or, at minimum, high-level disinfection.

Handling rules for needles, scalpel blades, and other sharp items, including never recapping by hand and disposing immediately in a rigid puncture-resistant container. It prevents needlestick injuries and bloodborne exposure.

A working model in which the assistant and dentist coordinate so instruments are transferred without the dentist looking away from the field. It improves efficiency, ergonomics, and patient safety.

Passing and receiving instruments in a consistent, predictable motion so the dentist grasps the handle without visual search. The transfer occurs near the patient's chin within the transfer zone.

The area over the patient's chest where the assistant's hands work and instruments are exchanged. Keeping this zone organized prevents contamination and reduces reaching across the patient.

A suction tip that removes large volumes of fluid, debris, and aerosol from the mouth during procedures. Correct placement near the operative site improves visibility and reduces airborne contamination.

A small suction device placed in the floor of the mouth to keep the field dry. It removes pooled saliva and water but is not designed to handle large debris or heavy fluid volume.

A latex or nonlatex sheet stretched over the teeth and held by a frame and clamps to isolate the working field. It protects the patient from debris, keeps the area dry, and improves infection control.

Measuring the depth of the gingival sulcus with a calibrated probe to assess attachment loss and disease. Depths are recorded at several sites per tooth and compared over time.

Bleeding provoked when a periodontal probe is inserted into the sulcus, indicating active inflammation. It is recorded as a yes or no finding and helps track response to periodontal therapy.

Recording the condition of each tooth and its surrounding tissues, including restorations, caries, mobility, and missing teeth. Accurate charting supports diagnosis, treatment planning, and legal documentation.

Gathering and updating the patient's health conditions, medications, allergies, and surgeries before treatment. It identifies risks such as bleeding disorders, drug interactions, and the need for antibiotic prophylaxis.

The patient's voluntary agreement to treatment after being told the diagnosis, options, risks, and consequences of declining. It must be documented and is required before invasive procedures.

A United States law that protects the privacy and security of patient health information. It limits who may access records and requires safeguards for electronic and paper data.

Any identifiable health data, such as charts, images, and billing records, that must be kept confidential. Sharing it requires patient authorization or a permitted legal exception.

The legally defined tasks a dental assistant may perform, which vary by state and may depend on supervision level. Performing outside that scope risks license discipline and patient harm.

A delegation level in which the dentist is physically present in the office and evaluates the patient before and after a procedure performed by the assistant. Many expanded functions require it.

Designing work positions and equipment to fit the body and reduce strain. In chairside practice it includes proper stool height, neutral posture, and positioning the patient to avoid reaching and twisting.