5.3 Instruments and Chairside Transfer

Instrument identification: the basic setup and hand instruments

California RDA candidates must recognize instruments by purpose, not just shape. Every restorative tray opens with the basic setup:

• Mouth mirror — indirect vision, retraction of cheek and tongue, and reflecting light onto the field.
• Explorer — a fine pointed tip the dentist uses to examine pits, fissures, margins, and surface texture.
• Cotton (college) pliers — locking or non-locking pliers that carry cotton, wedges, and small items.
• Periodontal probe — a blunt, calibrated tip for measuring sulcus and pocket depth.

Hand instruments are then grouped by function. A spoon excavator has a spoon-shaped cutting edge to remove soft, decayed dentin (used by the dentist). , discoid-cleoid, Hollenback — carves anatomy into amalgam), and composite placement instruments and plastic instruments for resin. A Tofflemire retainer, matrix bands, and wedges support proximal contour. Recognizing the difference between a condenser and a burnisher, or a discoid-cleoid carver and an explorer, is a common item type.

Hand-instrument function groups

Rotary handpieces and burs

Rotary instruments cut tooth structure and finish restorations. The high-speed handpiece is air-turbine driven, runs at roughly 400,000 rpm, and uses a water spray to cool the tooth and bur and to reduce frictional heat; it cuts enamel and old restorations. The low-speed (slow-speed) handpiece runs far slower (a few thousand to ~30,000 rpm), generates higher torque, and drives attachments for caries excavation, finishing, polishing, and — with a rubber cup or brush — coronal polishing, an allowable RDA duty after a Board-approved course.

Burs are classified by shape and shank:

Shanks match the handpiece: friction-grip (FG) for high-speed, latch-type (RA) for the low-speed contra-angle, and straight (HP) for the straight low-speed handpiece. The RDA prepares the correct bur, seats it fully so it locks, and changes it using the office's safe method — never grasping a contaminated, spinning, or hot bur with bare fingers. Diamond rotary instruments (a diamond-coated working end) cut and reduce enamel for crown preparations, while multi-bladed carbide finishing burs and abrasive discs, points, and cups smooth and polish completed restorations.

Knowing which rotary belongs to cutting versus finishing helps the RDA stage burs in sequence so the dentist is never waiting for the next one.

Instrument grasps and the assistant's role

The operator holds most instruments in a modified pen grasp for fine control, a palm grasp for forceps, or a palm-thumb grasp for some chisels; the RDA orients each instrument so it arrives in the working position for that grasp. Mirror and explorer are passed as a pair at the start of an exam; the assistant keeps the mirror clear with the air-water syringe so the operator retains indirect vision. Throughout, the RDA keeps the field dry and visible, transfers in rhythm with the operator's hand, and parks used instruments back on the tray in their sequence — the operatory equivalent of "a place for everything."

Single-handed instrument transfer

Four-handed transfer happens in the transfer zone over the patient's chest. In the standard single-handed transfer, the RDA holds the new instrument parallel to the one in use, retrieves the used instrument with the little finger, rotates, and delivers the new instrument handle-first into the operator's grasp so the dentist never looks away or repositions the hand. Pointed instruments are passed by the handle with the tip directed away from the patient and team, and never over the face. Suction should not pull the cheek or tongue into the tip, and retraction should protect soft tissue without excess pressure.

Finally, recognizing an instrument is not authorization to use it for every purpose. The RDA may prepare, pass, receive, and manage instruments; whether the RDA performs a specific intraoral procedure depends on California scope, training, and dentist supervision. The RDA may, for example, polish the coronal surfaces of teeth with a rubber cup and prophy paste on the low-speed handpiece after a Board-approved course, but may not use a bur to cut tooth structure, remove caries, or perform any irreversible or surgical step — those remain the dentist's duties.

When a question has the RDA independently diagnosing, cutting tissue, or preparing a tooth, choose the answer that assists, reports, or waits for direction. Study by building sequences: for each procedure, ask what is held first, what is transferred next, what must stay sterile, what becomes contaminated, what is sharp, and what supports visibility — that sequence-based mindset matches the exam's duty-based design and keeps instrument names tied to real chairside practice rather than detached flashcards.