Dental Practice Act and Scope of Practice
The statute and its architecture
Every jurisdiction regulates dentistry through a dental practice act, usually paired with board rules. The act defines who may practice dentistry, sets the corporate structure of the board, and delegates operational detail to administrative rules. For exam purposes, treat the statute as controlling over rules, and rules as controlling over informal board guidance or policy statements. A frequent trap is a question offering a practice that is "customary" or "widely done" - custom never expands scope.
Defining the practice of dentistry
Know the statutory definition: diagnosis, treatment planning, and treatment of conditions of the oral cavity and adjacent structures; performing operations; prescribing drugs; and holding oneself out to the public as able to do these things. The definition usually includes a "holding out" clause, so an unlicensed person who advertises dental services commits a violation even before treating anyone.
Delegation and supervision
Scope questions almost always turn on the level of supervision attached to a task. Learn the jurisdiction's ladder: direct supervision (licensed dentist on premises and examining the patient), indirect supervision (dentist on premises or immediately available, patient previously examined), and general supervision (dentist authorized the procedure but need not be present). Expanded-function duties - coronal polishing, sealants, radiographs, nitrous oxide monitoring, certain restorative functions - are each assigned a specific tier and often a specific credential. Traps: assuming a hygienist's license covers every hygiene-adjacent task; assuming a dental assistant may perform irreversible procedures; confusing local anesthesia or nitrous administration rules, which are frequently singled out.
Rule of thumb
If a task involves diagnosis, treatment planning, prescribing, or an irreversible/surgical act, presume it is reserved to the dentist unless the act expressly delegates it with a named supervision level. When a question gives no supervision language, the safest answer is the more restrictive one.
Worked example
A question asks whether an assistant may take a final impression for a crown. Impressions for a definitive restoration require the dentist's diagnostic judgment and are typically direct-supervision or nondelegable; the answer is no unless the act expressly lists it.