Coronal Polishing practice test, every answer explained

Answer: A. They metabolise it into an acid that is held against the enamel

The subcourse describes carbohydrate going into solution, penetrating the deposit, and being metabolised there into acid. Because that acid is held in place and sits directly against the tooth, it demineralises enamel and begins caries. The pigment answer describes stain, the calcium answer describes the mineralisation that turns the deposit hard, and the toxin answer describes the separate route by which deposit near the gum margin harms periodontal tissue.

Source: Preventive Dentistry (subcourse MD0513), U.S. Army Medical Department Center and School; section “2-10. DENTAL PLAQUES”. U.S. government work, public domain.

Answer: B. Taking plaque, debris and stain off the surfaces of the tooth

The regulation's definition is functional and names three things to be removed: plaque, debris and stain, taken off the tooth mechanically. Putting a shine on enamel that is already clean is not the job it names, and holding the formulation together or delivering the active ingredient are the work of other components of the product.

Source: 21 CFR Part 355, Anticaries Drug Products for Over-the-Counter Human Use, U.S. Food and Drug Administration (CFR 2024, govinfo); section “355.3 Definitions”. U.S. government work, public domain.

Answer: B. Keep suitable alternatives, such as glove liners, readily to hand

The standard answers an allergy by changing the glove rather than the person's duties or their paperwork: substitutes that avoid the offending material, among them liners and powder-free stock, must be within reach of a worker who reacts to what is normally issued. Reassignment, self-supply and medical clearance are not what the rule asks for.

Source: 29 CFR 1910.1030, Bloodborne Pathogens, Occupational Safety and Health Administration; section “1910.1030(d)(3)(iii)”. U.S. government work, public domain.

Answer: D. Water is flushed in and the patient holds the saliva ejector

Clearing as you go keeps the surface visible and stops slurry pooling in the floor of the mouth. Water comes from the three-way syringe, and the patient is handed the low-volume tip so debris is drawn off continuously. Leaving everything until the end makes the surfaces still to come much harder to judge.

Source: Dental Technician, Volume 2 (NAVEDTRA 14275), U.S. Navy, 1999; section “Polishing Routine”. U.S. government work, public domain.

Answer: A. the chewing surfaces, with their pits and grooves

Stiff bristles reach down into a groove that a smooth rubber rim simply rides over, so the brush is kept for the occlusal table and the fissure pattern within it. Wherever the surface is broad and smooth, or close to soft tissue, the cup is the safer carrier. Closed contacts remain the job of floss or tape.

Source: Preventive Dentistry (subcourse MD0513), U.S. Army Medical Department Center and School; section “3-21. POLISHING WITH PROPHYLAXIS PASTE”. U.S. government work, public domain.

Answer: A. Well clear of the gum, with the bristles kept off the soft tissues

The brush is the stiffest of the three carriers, so its permitted ground is the occlusal table and a margin of clear space is asked for between the bristles and the tissue. Bringing it down to the neck of a tooth, or letting it graze a margin that merely looks healthy, throws that margin of safety away. Running the handpiece slowly does not buy back the clearance.

Source: Dental Technician, Volume 2 (NAVEDTRA 14275), U.S. Navy, 1999; section “Precautions”. U.S. government work, public domain.

Answer: B. The heat that builds up can reach the pulp and cause pain

Rubber turning against enamel makes heat, and a cup that lingers over one point raises the temperature there faster than the tooth can carry it away. The same paragraph deals with that by holding the handpiece to its lowest speed and never letting the cup rest, so no one spot is loaded for long. The patient feels it as pain, and it is the pulp the warning is protecting.

Source: Dental Technician, Volume 2 (NAVEDTRA 14275), U.S. Navy, 1999; section “Precautions”. U.S. government work, public domain.

Answer: C. The cup is brought up to the tooth first, then set turning

A loaded cup that is already turning throws its contents outward before it ever meets a tooth. Closing the gap first and starting the rotation almost against the surface keeps the abrasive where it was put. This is a matter of the order of two actions, not of how much paste was loaded.

Source: Dental Technician, Volume 2 (NAVEDTRA 14275), U.S. Navy, 1999; section “Precautions”. U.S. government work, public domain.

Answer: C. It lifts that same material out again as it is drawn through

The floss does two jobs in one pass. It is the only carrier that will enter a closed contact, so the polishing agent goes in on it; and drawing it through lifts that agent out again, which is the purpose the manual states for the step. Burnishing a contact against future stain is not a claim the manual makes, the pass does not stand in for the rinse that ends the appointment, and nothing is meant to be left behind between the teeth.

Source: Preventive Dentistry (subcourse MD0513), U.S. Army Medical Department Center and School; section “3-14. POLISHING”. U.S. government work, public domain.

Answer: D. No paste can reach it, because the colour lies within the enamel and the dentin.

A discolouration laid down while the teeth were forming is carried inside the tooth. The pigment is taken up into the crystal structure of enamel and dentin, so there is nothing on the surface for a cup, a brush or a paste to lift off. More minutes on the tooth, a coarser grit or a change of attachment all work on the outside, which is not where this colour sits, and it is not a deposit that re-forms after a polish either. Changing how the banding looks is a treatment-planning discussion, not something a polish can deliver.

Source: Preventive Dentistry (subcourse MD0513), U.S. Army Medical Department Center and School; section “2-12. STAINS”. U.S. government work, public domain.