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17. Which topical anesthetic has the most rapid onset of action? a. Benzocaine b. Lidocaine c. Dyclonine hydrochloride d. Tetracaine hydrochloride

(a) Benzocaine has the most rapid onset of action, which can occur within 30 seconds.

15. Which of the following is NOT an ideal property of an oral topical anesthetic? a. It produces dependency on repeated use. b. It remains at the site of application. c. It has an acceptable taste. d. It permits a comfortable (pain-free) application.

(a) Cocaine, as an oral topical anesthetic, was addictive and stimulated dependency. It was eventually replaced with topical anesthetics that were not addictive.

7. Which of the following is a eutectic mixture that will thicken into a gel once inserted into a periodontal pocket, relieving pain associated with nonsurgical periodontal therapy? a. Oraqix (2.5% lidocaine/2.5% prilocaine gel) b. EMLA (2.5% lidocaine/2.5% prilocaine cream) c. Cetacaine (benzocaine, butamben, tetracaine) d. Dyclonine hydrochloride

(a) The eutectic mixture of lidocaine and prilocaine in Oraqix will thicken (from a liquid to a gel) in the periodontal pocket, providing effective soft tissue anesthesia.

14. The FDA has released a Public Health Advisory alerting consumers to the potential risk of life-threatening or fatal reactions to over-the-counter topical anesthetics. Some of these over-the-counter topical anesthetics are available in concentrations twice the strength of those used in the dental office a. The first statement is true; the second statement is false. b. The first statement is false; the second statement is true. c. Both statements are true. d. Both statements are false.

(a) The first statement is true: this advisory was released in 2007 and then again in 2009. The second statement is false: over-the-counter topical anesthetic is available in concentrations equal to those used in the dental office.

2. To achieve the optimal anesthetic effect, topical anesthesia should remain at the site of application for _______. a. 1 to 2 minutes b. 3 to 5 minutes c. 5 to 10 minutes d. 10 to 12 minutes

(a) Topical anesthesia should remain at the site of application for 1 to 2 minutes in order to achieve the desired anesthetic effect.

11. A toxic overdose of topical anesthetic may result in which of the following? a. Hypertension b. Bradycardia c. Tachycardia d. Both A and B

(b) Bradycardia (heart beating too slowly) and hypotension are cardiovascular consequences in a toxic overdose of topical anesthetic and may, in some cases, lead to cardiac arrest.

13. Mild allergic reactions to topical anesthetic can include _______, _______, and _______. a. hematoma, cyanosis, nausea b. swelling, raised welts, itching c. slurred speech, drowsiness, difficulty breathing d. seizures, unconsciousness, respiratory arrest

(b) Swelling, raised welts on the skin, and itching or burning are all mild allergic reactions to topical anesthetic.

3. Topical anesthesia will anesthetize the affected area _______ into the tissue. a. 1 to 2 mm b. 2 to 3 mm c. 3 to 5 mm d. 5 to 7 mm

(b) The effect of topical anesthesia will penetrate the tissue 2 to 3 mm.

12. Allergic reactions to topical anesthetic are _______. a. very common b. somewhat common c. rare d. unheard of

(c) Allergic reactions, even to the esters benzocaine and tetracaine, are rare.

4. Topical anesthesia is available in many different forms: liquid, gel, spray, and patch. Topical anesthesia distributed in single dose applications decreases the possibility of cross-contamination. a. The first statement is true; the second statement is false. b. The first statement is false; the second statement is true. c. Both statements are true. d. Both statements are false.

(c) Both statements are true.

6. Which topical anesthetic is not classified as an ester or an amide, but as a ketone? a. Benzocaine b. Lidocaine c. Dyclonine hydrochloride d. Tetracaine hydrochloride

(c) Dyclonine hydrochloride is uniquely classified as a ketone.

19. A patient who has just been administered Oraqix gel (2.5% lidocaine and 2.5% prilocaine) can expect a comfortable duration of anesthesia of approximately _______. a. 60 minutes b. 45 minutes c. 20 minutes d. 10 minutes

(c) The average duration of anesthesia for Oraqix gel is 20 minutes.

1. Which of the following is NOT an appropriate use for topical anesthesia? a. To increase comfort during minor dental hygiene procedures b. To reduce a patient's gag reflex while taking dental impressions c. To minimize the pain associated with needle insertion d. To achieve pulpal anesthesia prior to restorative dental procedures

(d) Because topical anesthesia is applied to the surface of the skin or mucosa, it is not an effective pulpal anesthetic.

8. Topical anesthetics have a lower concentration of anesthetic than their injectable counterparts. This is necessary because some topical anesthetics contain a vasoconstrictor. a. The first statement is true; the second statement is false. b. The first statement is false; the second statement is true. c. Both statements are true. d. Both statements are false.

(d) Both statements are false. Topical anesthetics have a higher, not lower, concentration of anesthetic than their equivalent in an injectable form. Topical anesthetics do not contain a vasoconstrictor.

20. Drying the mucosa with 2 × 2 gauze, prior to the application of topical anesthesia, assists in _______. a. accurate placement of the topical anesthetic b. increasing the visibility c. increasing the penetration depth to 5 mm d. Both A and B

(d) Drying the tissue with gauze before applying topical will assist the clinician by increasing the visibility and in achieving an accurate placement of the anesthetic.

18. Oraqix gel (2.5% lidocaine and 2.5% prilocaine) produces an anesthetic effect within ____________. a. 15 minutes b. 10 minutes c. 5 minutes d. 30 seconds

(d) Oraqix gel has a rapid onset of action that occurs within 30 seconds.

5. Which topical anesthetic has the longest average duration? a. Benzocaine b. Lidocaine c. Dyclonine hydrochloride d. Tetracaine hydrochloride

(d) Tetracaine hydrochloride is the most potent topical anesthetic with an average duration of 45 minutes.

16. Topical anesthetics are available in a variety of forms. Which method of delivery is most likely to produce a toxic reaction? a. Patch b. Gel c. Applicator swab d. Spray

(d) To avoid a toxic reaction, the clinician should limit the area of application by avoiding topical anesthetic sprays.

9. Of the following patients, which is most likely to have a negative reaction to topical anesthetic? a. A child b. A patient of Middle Eastern ancestry c. A patient with type O+ blood d. All of the above

: (a) Children, the elderly, and medically compromised patients are most susceptible to adverse reactions to topical anesthetic.

10. Which of the following are symptoms of a localized reaction to topical anesthetic? a. Irritation, burning, and stinging at the site of application b. Dizziness, tinnitus, and involuntary muscular activity c. Tissue sloughing or discoloration and temporary change in taste perception d. Both A and C

: (d) Answers A and C are both correct: irritation, burning, stinging, tissue sloughing, discoloration, and temporary change in taste perception are all signs/symptoms of a localized negative reaction to topical anesthetic.