Plaque Control

Periodontics  ›  Treatment

Plaque Control: Mechanical & Chemical

High-yield revision notes with linked practice questions, written for dental students and candidates preparing for the ADC and other licensing examinations.

High-yield notes

Lingual surfaces accumulate the least amount of plaque.

Diameters of common bristles range from

  • 0.007 inch (0.2 mm) for soft brushes to
  • 0.012 inch (0.3 mm) for medium brushes and
  • 0.014 inch (0.4 mm) for hard brushes

The ADA recommends that toothbrushes be replaced every 3 to 4 months.

Abrasives content in toothpaste is 20-40% whereas powder is 95%.

Dentin is abraded 25 times faster and cementum 35 times faster than enamel.

"Target hygiene" achieved with sulcular brushing technique.

The purpose of interdental cleaning is to remove microbial plaque, not just dislodge food wedged between teeth.

Waxed dental floss do not deposit wax on tooth surfaces. (Perry DA, Pattison G: The investigation of wax residue on tooth surfaces after the use of waxed dental floss. Dent Hygiene 1986; 60:16.)

Irrigation performed in the dental office, also called lavage or flushing of the periodontal pocket.

Subgingival irrigation at home is not the oral hygiene procedure of choice for patients requiring antibiotic prophylaxis before dental treatment, particularly if extensive inflammation is present.

If chlorhexidine does not stain the tooth, it does not work.

10 ml of 0.2% solution contains 20 mg chlorhexidine which has a similar effect as 17 ml of 0.12% chlorhexidine (~15ml=18 mg dose)

Practice questions

Select an option to check your answer. Answers are shown below each question.

Question 1

In healthy subjects the plaque formation begins on the

  • AInterdental surfaces
  • BFacial surface
  • CLingual surface
  • DFacial surface on maxilla and lingual surface on mandible
Answer: A. Interdental surfaces
Question 2

To achieve caries reduction process, the concentration of fluoride in dentrifices should be

  • A0.7-1.2 ppm
  • B10-100 ppm
  • C500-800 ppm
  • D1000-1100 ppm
Answer: D. 1000-1100 ppm
Question 3

"Calculus control toothpastes," also referred to as "tartar control toothpastes," contain

  • ADiphosphates
  • BPyrophosphates
  • CTriple phosphates
  • DZinc phosphates
Answer: B. Pyrophosphates
Question 4

Themost widely recommended tool for removing plaque from proximal tooth surface is

  • ADental floss
  • BWooden tips
  • CPlastic tips
  • DInterdentalbrushes
Answer: A. Dental floss
Question 5

Recommended length of dental floss for flossing technique is

  • A5-10 inch
  • B6-12 inch
  • C12-18 inch
  • D30-45 inch
Answer: C. 12-18 inch
Question 6

Type II gingival embrasures

  • Aembrasures with no gingival recession
  • Badequately cleaned using dental floss
  • Clarger spaces with exposed root surfaces
  • Dsingle-tufted brushes clean efficiently
Answer: C. larger spaces with exposed root surfaces
Question 7

Not an essential oil mouth rinses

  • AThymol
  • BEucalyptol
  • CChlorhexidine
  • DMenthol
Answer: C. Chlorhexidine
Question 8

Not a side effect of chlorhexidine

  • ABrown discoloration of the teeth
  • BTaste perturbation where the salt taste appears to be preferentially affected
  • CEnhanced supragingival calculus formation
  • DOral cancer
Answer: D. Oral cancer
Question 9

Supragingival plaque control reduces

  • APocket depth
  • BGingival inflammation
  • CLoss of attachment
  • DAll of the above
Answer: B. Gingival inflammation
Question 10

Chlorhexidine digluconate is

  • ASoluble in water
  • BSparingly soluble in water
  • CInsoluble in water
  • DPartially insoluble in water
Answer: A. Soluble in water lindhe page 748
Question 11

Most oral formulations and products have used the chlorhexidinedigluconate salt, which is manufactured as a

  • A2% V/V concentrate.
  • B0.2 % V/V concentrate.
  • C20% V/V concentrate.
  • D1% V/V concentrate.
Answer: C. 20% V/V concentrate.
Question 12

Chlorhexidine is

  • Aa strong acid and dicationic at pH levels below 3.5
  • Ba strong base and dicationic at pH levels below 3.5
  • Ca strong base and dicationic at pH levels above 3.5
  • Da strong acid and dicationic at pH levels above 3.5
Answer: C. a strong base and dicationic at pH levels above 3.5
Question 13

Which of the following is not the mechanisms proposed for chlorhexidine staining

  • ADegradation of the chlorhexidine molecule to release parachloraniline
  • BCatalysis of Maillard reactions
  • CProtein denaturation with metal sulfide formation
  • DPrecipitation of cationic dietary chromogens.
Answer: D. Precipitation of cationic dietary chromogens. lindhe page 749
Question 14

Chlorhexidine is a useful mouthwash as [2072/12/1]

  • AIt prevents plaque accumulation.
  • BIt prevents bacterial proliferation
  • CIt breaks down plaque matrix
  • DIt causes haemostasis
Answer: A. It prevents plaque accumulation.
Question 15

Not true about chlorhexidine

  • AAt low concentration this binds to bacterial cell membrane and results in increased permeability with leakage of intracellular components including potassium.
  • BPlaque inhibition is derived only from the chlorhexidine adsorbed to the tooth surface.
  • CIf chlorhexidine does not stain the tooth, it does not work.
  • DThe molecule attaches to pellicle by both cation making the attachment stronger.
Answer: D. The molecule attaches to pellicle by both cation making the attachment stronger.
Question 16

PIN-CUSHION EFFECTis responsible for

  • AInhibiting bacteria to colonize the tooth surface.
  • BStaining of the tooth by chlorhexidine
  • CReduction in the plaque inhibition of chlorhexidine by toothpaste if used shortly after rinses with the antiseptic.
  • DAll of the above
Answer: D. All of the above
Question 17

First modern tooth brush was invented by

  • AChinese
  • BEnglish
  • CAmerican
  • DJapanese
Answer: B. English

These notes are compiled from standard periodontology texts for study purposes. They are a revision aid, not a substitute for your own reading or current clinical guidelines. If you spot an error, please leave a comment.