The ADEX dental hygiene examination administered by the CDCA (Commission on Dental Competency Assessments) is a regional clinical licensure exam accepted in more than 30 states. It evaluates a candidate's ability to perform scaling and root planing on a live patient under standardized conditions, and it includes a written component covering biomedical sciences, dental hygiene sciences, and patient care. Because both the clinical and written portions must be passed, thorough preparation across all subject areas is essential before your exam date.
This page provides a free printable ADEX dental hygiene practice test PDF alongside content reviews of the major written exam topics. Download the PDF, study it offline, and use the checklist and FAQ below to reinforce the concepts that carry the most weight on both the written and clinical components of the exam.
A solid command of dental and oral anatomy underpins both the written and clinical portions of the ADEX exam. The written component tests your knowledge of tooth morphology—crown and root anatomy for all 32 permanent teeth and the 20 primary teeth—including root trunk length, root curvature, furcation location, and the number and arrangement of roots. These details matter during the clinical exam because you must adapt your instrumentation technique to the specific anatomy of each tooth you scale. Furcations present particular challenges, and questions about furcation classifications (Class I, II, III) and the instruments used to detect and scale them appear regularly on both practice materials and the written exam.
The oral pathology component of the ADEX written exam requires you to identify and classify mucosal lesions, differentiate benign from potentially malignant conditions, and understand the etiology and clinical presentation of common oral diseases. You should be familiar with the descriptive terminology used to document lesions (macule, papule, vesicle, ulcer, plaque, nodule) and know the distinguishing features of conditions such as aphthous ulcers, oral candidiasis, leukoplakia, erythroplakia, lichen planus, and herpetic lesions. Systemic diseases with oral manifestations—including diabetes, HIV/AIDS, and autoimmune conditions—are tested because dental hygienists play a role in identifying patients who may need medical referral. Practice questions in oral pathology often present a clinical description and ask you to select the most likely diagnosis or the appropriate next step.
Periodontology is the clinical core of the ADEX exam. The written portion tests the classification of periodontal diseases (using the 2017 AAP/EFP classification system), the etiology of periodontal disease including the role of bacterial biofilm, host response, and risk factors such as smoking and diabetes, and the rationale for non-surgical periodontal therapy. You must understand probing, recording, and interpreting a full periodontal chart, including pocket depth, clinical attachment level (CAL), bleeding on probing, furcation involvement, mobility, and recession measurements. The relationship between probing depth and CAL is a common exam topic: a 5 mm pocket with 2 mm of recession represents 7 mm of total attachment loss, and questions frequently test whether you can make this calculation correctly.
The clinical portion of the ADEX exam directly assesses your scaling and root planing technique on a live patient. Examiners evaluate deposit removal thoroughness, root surface smoothness, soft tissue trauma, patient management, and instrument selection. On the written exam, questions about instrumentation cover the design features of hand instruments (sickle scalers, curettes—universal vs. area-specific, explorers, probes), correct adaptation and angulation of the cutting edge to the root surface, and the principles of power scaling with ultrasonic devices. You must know the activation strokes (working stroke vs. exploratory stroke), the correct blade-to-tooth angulation (45–90°), and the rationale for choosing a gracey curette over a universal curette for a specific surface. Sharpening technique and the lateral pressure applied during scaling are also tested.
The dental hygiene sciences and patient care domains of the ADEX written exam cover the full scope of dental hygiene practice, from health history review and vital signs to oral hygiene instruction and treatment planning. You must be able to identify medical conditions and medications that require treatment modifications, including anticoagulants, bisphosphonates, antihypertensives, and corticosteroids. Patient assessment questions may describe a medical history and ask which findings require follow-up or alter the treatment plan. Nutritional counseling, tobacco cessation, and caries risk assessment are topics that reflect the preventive focus of the dental hygiene profession and appear consistently in the written exam question pool.
Dental radiography questions on the ADEX written exam test film and sensor selection, technique errors and how to correct them, radiation protection principles, and interpretation of radiographic findings relevant to dental hygiene practice—including calculus detection, bone level assessment, and periapical pathology. Infection control questions draw heavily from CDC guidelines and OSHA Bloodborne Pathogen Standard requirements, covering personal protective equipment, instrument sterilization and disinfection, surface asepsis, and the proper management of sharps injuries. These are high-yield content areas because the questions are factual and specific, making them easier to study for than clinical judgment questions.
The biomedical sciences domain covers anatomy, physiology, microbiology, pharmacology, and biochemistry as they apply to dental hygiene practice. Head and neck anatomy—including the muscles of mastication, the major salivary glands, the lymph nodes, and the innervation of the oral cavity—is particularly important because dental hygienists must understand local anesthesia delivery and recognize signs of lymphadenopathy. Microbiology questions address the specific bacteria associated with caries (Streptococcus mutans, Lactobacillus spp.) and periodontal disease (Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia) and the mechanisms of antibiotic action relevant to adjunctive periodontal therapy. Pharmacology questions often focus on drug-drug interactions, local anesthetic agents and vasoconstrictors, analgesic choices for post-treatment pain, and the management of medical emergencies in the dental office. A thorough review of your dental pharmacology textbook alongside the PDF practice questions will prepare you for this domain.
A preparation plan that combines written content review with hands-on clinical practice is the most effective approach to passing both components of the ADEX exam. Use the checklist above to track your progress through each subject area, focus extra study time on periodontology and biomedical sciences where question volume is highest, and review your PDF answers against the explanations before your exam date. For additional timed practice questions with scoring and detailed rationales, visit our adex dental exam page.