Dental assistant screening questions: x-ray credentials, expanded functions and chairside skills
On this page
- State rules decide which duties the candidate can take on
- Credential and certification questions
- Chairside skills: strong answers and red flags
- Specialty fit
- Software, front office and pace
- Where dental assistant experience gets overstated
- Knockout checklist and scoring
- Lawful phrasing for dental assistant screens
- Questions people ask
Dental assistant screening questions should settle whether the candidate can legally perform the duties the practice needs on day one in the job's state (x-rays above all, and any expanded functions), whether they have done those duties recently and at the office's pace, and whether they already know the practice's software and specialty. A strong chairside assistant from one state may not be allowed to take radiographs in another until they complete that state's course or registration.
This bank is for recruiters placing dental assistants in general dentistry, DSOs, orthodontics, oral surgery, pediatrics and endodontics, on temp, temp-to-hire and permanent terms. The medical assistant screening questions cover physician offices, where duties are delegated under medical board rules; dental assistants work under a separate dental practice act in each state, with different credentials.
State rules decide which duties the candidate can take on
There is no single national license for dental assistants. The Dental Assisting National Board offers national certifications, and each state's dental board sets which duties assistants may perform and what training or credential each requires. Two examples as of September 2026:
- Texas: the Texas State Board of Dental Examiners says a dental assistant must hold a Dental Assistant Radiology Certificate to position or expose dental x-rays. Requirements include a hands-on BLS course, fingerprints, and either an approved course and exam or a current DANB certificate plus the board's jurisprudence assessment (radiology certificate requirements).
- California: the Dental Board of California says an unlicensed dental assistant may operate radiographic equipment only after passing a board-approved radiation safety course, and must complete a board-approved 8-hour infection control course before basic supportive procedures with exposure to blood or saliva. Higher duties require the Registered Dental Assistant or RDA in Extended Functions license (allowable duties FAQ).
Other states range from no assistant-specific requirement for basic duties to multiple tiers of registration. DANB publishes a state-by-state overview, but confirm the details on the state dental board's own site, and ask the client which duties the role needs.
Intake questions for every dental assistant order: Does the assistant take x-rays? Which expanded functions are expected (coronal polish, sealants, temporaries, impressions or scans)? Which practice management software and imaging system? Which specialty, and how many chairs will the assistant cover?
Credential and certification questions
| Question | What a strong answer sounds like | Red flags |
|---|---|---|
| In which state are you qualified to take x-rays, and what is the credential called? | "Texas, I have my dental assistant radiology certificate, it renews next June." The state, the credential's name, and a renewal date. | "I took x-rays at my last office" with no credential, in a state that requires one. |
| Do you hold any DANB certification? Which one? | Names it (CDA, or a component such as RHS or ICE, or a specialty certification such as COA for orthodontic assistants) and whether it is current. | Claims CDA but has passed only one component exam. |
| Which expanded functions are you credentialed for, and in which state? | Names the duty and the state credential or course: "coronal polish and sealants, California RDA." | Lists duties performed in a state where the credential they hold does not allow them. |
| Is your BLS or CPR card current, and is it hands-on? | Current card from a course with an in-person skills check, and the expiry date. | Online-only card, where the state or client requires hands-on. |
| Have you moved states? Did you apply for the new state's credential? | Knows what the new state requires and has applied or booked the course. | Assumes the old state's credential carries over. |
DANB certification has three component exams for the CDA: Radiation Health and Safety, Infection Control and General Chairside Assisting, passed within five years, with annual renewal through continuing education (DANB CDA exam). Verify certification with DANB and state credentials on the state board's license lookup.
Chairside skills: strong answers and red flags
-
"Walk me through setting up and assisting for a two-surface composite."
- Strong answer: reviews the chart and treatment plan, sets out the tray for the procedure, anesthetic setup for the dentist, isolation (rubber dam or isolation system), matrix, bonding steps in order, curing light, high-volume suction positioned without being asked.
- Red flags: a generic answer that could apply to any procedure. Cannot say what goes on the tray.
-
"Which radiographs did you take on a normal day, and on what system?"
- Strong answer: bitewings, periapicals and full-mouth series on digital sensors, panoramic, and cone beam if the office had one, naming the imaging software (Dexis, Carestream, Planmeca Romexis, Sirona) and how they handled retakes.
- Red flags: retakes "until it looks right" with no thought for exposure, or only film experience for an all-digital office.
-
"How do you turn over an operatory between patients?"
- Strong answer: removes and handles sharps and instruments safely, cleans and disinfects surfaces with the product's contact time, replaces barriers, flushes waterlines as the office protocol requires, sets up for the next patient.
- Red flags: wipes down quickly without mentioning contact time or barriers.
-
"Walk me through instrument processing in your last office."
- Strong answer: transport, cleaning (ultrasonic or washer), packaging, sterilizing, and the monitoring: chemical indicators every pack and biological spore tests on the office's schedule, with a log.
- Red flags: does not know about spore testing, or never checked indicators.
-
"Have you taken impressions or intraoral scans? For what?"
- Strong answer: which (alginate for study models, final impressions if the state allows, scanning with iTero or Primescan or similar) and which appliances or restorations they supported.
- Red flags: took final impressions in a state where that duty required a credential they did not hold.
-
"Tell me about a medical emergency or a patient who became unwell in the chair."
- Strong answer: a specific event (fainting, a hypoglycemic patient, an allergic reaction), their role, knowing where the emergency kit and oxygen are.
- Red flags: no idea where emergency equipment was kept.
Specialty fit
Specialty practices pay for experience because training a new assistant in their procedures takes months. Ask what they did, not only where they worked.
| Specialty | Ask | Listen for |
|---|---|---|
| Orthodontics | "Which tasks did you do on adjustment visits?" | Removing and placing archwires and ligatures, bracket setup, scans for aligners, and whether the state allows each; a patient-per-day number, since ortho is high volume |
| Oral surgery | "What was your role during IV sedation cases?" | Monitoring as allowed by the state (some require a sedation assistant permit), sterile field, extractions and implants, post-op instructions |
| Pediatric | "How did you help with a child who would not open?" | Tell-show-do, working with parents, open-bay clinics, speed |
| Endodontics | "Walk me through a molar root canal from your side." | Rubber dam, microscope assisting, rotary files, apex locator, obturation materials |
| General practice or DSO | "How many chairs did you cover, and for which providers?" | Moving between a dentist and hygienists, crown prep and same-day restorations, schedule pace |
Software, front office and pace
| Question | What a strong answer sounds like | Red flags |
|---|---|---|
| Which practice management software did you use, and what did you do in it? | Names it (Dentrix, Eaglesoft, Open Dental, Curve, Denticon, or a DSO platform) and tasks: clinical notes, charting existing conditions and treatment, perio charting, treatment plans. | "The front desk handled the computer." |
| How many patients did your dentist see on a typical day, and how many chairs did you run? | A number and the setup: "about 18 patients, I ran two chairs." | No sense of volume. Compare to the client's schedule. |
| Can you do front desk cover: check-in, insurance verification, scheduling? | Specific tasks done, and how often. | Says yes to everything without examples, for a hybrid role. |
| How do you document a procedure note for the dentist to review? | Uses the office templates, records anesthetic type and amount as dictated, materials and shade, and the dentist signs. | Writes notes after the patient has left, from memory. |
Where dental assistant experience gets overstated
| Resume says | Ask | Often turns out to be |
|---|---|---|
| "Registered dental assistant" | "Which state's registration, and what does it allow?" | A course certificate, or a registration from another state |
| "Expanded functions" | "Which ones, under which credential?" | Duties done without the credential, or observed in school |
| "Oral surgery experience" | "How many sedation cases a week did you assist?" | A general practice that referred surgery out and did simple extractions |
| "Office manager / lead assistant" | "Did you set schedules, order supplies, or train others?" | Most senior assistant, no management duties |
| "Cone beam and digital imaging" | "Did you take the scans, or just open them?" | Viewed images the dentist took |
Knockout checklist and scoring
Knockouts (all must be yes)
- Holds the x-ray credential or course the job state requires, if the role takes radiographs, verified with the state board.
- Holds the state credential for every expanded function the client needs on day one, or the client accepts training.
- Current BLS or CPR, in the format the state or client requires.
- Recent chairside experience in a comparable practice type.
- Describes infection control and sterilization monitoring correctly.
- Can work the office's days and hours, including any evening or Saturday sessions.
| Area | 1 | 2 | 3 |
|---|---|---|---|
| Credentials for the role's duties | Missing for a day-one duty | In progress, done before start | All current in the job state |
| Chairside depth | Generic answers | Solid on common procedures | Anticipates the dentist, specific setups |
| Infection control | Gaps in basics | Correct when prompted | Describes monitoring and logs unprompted |
| Specialty and software match | Neither | One of the two | Both, recent |
| Pace | Low-volume office | Moderate | Comparable or busier than the client |
Lawful phrasing for dental assistant screens
| Do not ask | Ask instead |
|---|---|
| "Are you pregnant? There is radiation exposure." | Do not ask. Describe the duties; radiation safety and dosimetry are the practice's responsibility and any accommodation request is handled by the employer. |
| "Any problems with your back or hands?" | "The role involves sitting chairside for long periods and fine hand work. Can you do that, with or without accommodation?" |
| "Have you had your hepatitis B vaccine?" | Leave immunization questions to the employer's post-offer process. |
| "How old are your children?" | "The office runs two late evenings a week and one Saturday a month. Can you work that?" |
The state, the credential name and the list of expanded functions are easy to confuse across a day of calls with candidates from different states. Interview Signal keeps a transcript on your own computer and builds a question guide from the job order, so the credential questions are asked every time and the submittal carries what the candidate actually said. For checking chairside skills afterwards, ask for a dentist reference; the reference check template has the questions.
Questions people ask
Do dental assistants need a license to take x-rays?
In many states, yes, some form of state credential or approved course is required. Texas requires a Dental Assistant Radiology Certificate from the State Board of Dental Examiners to position or expose x-rays, and California requires unlicensed assistants to pass a board-approved radiation safety course. Check the dental board of the state where the job is.
What is DANB's CDA certification?
Certified Dental Assistant is the national certification from the Dental Assisting National Board. It is made up of three component exams: Radiation Health and Safety (RHS), Infection Control (ICE) and General Chairside Assisting (GC), which DANB says must be passed within five years. DANB certifications are renewed annually with continuing education.
Does a DANB certification let an assistant work in any state?
No. DANB certification is national, but duties are set by each state's dental practice act. Some states accept DANB exams toward their own credential, others require a state registration, license or permit on top. Treat DANB as evidence of knowledge, and the state credential as what allows specific duties.
What are expanded functions in dental assisting?
Duties beyond basic chairside support that a state allows qualified assistants to perform, often with extra training or a separate credential. Examples in some states include coronal polishing, sealants, placing and carving restorations, or orthodontic tasks. Titles such as EFDA or RDAEF and the allowed duties vary by state.