Effect of a new local anesthetic buffering device on pain reduction during nerve block injections

Self-Instruction Exercise No. 378
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Exercise No. 378
Subject Code: 132
Anesthesia and Pain Control

The 15 questions for this exercise are based on the article, Effect of a new local anesthetic buffering device on pain reduction during nerve block injections, on pages 74-78. This exercise was developed by Robert A. Busto, DMD, MBA, FAGD, in association with the General Dentistry Self-Instruction committee.

Reading the article and successfully completing this exercise will enable you to:

  • review nociception;
  • review the general mechanism of action of local anesthetics; and
  • understand the concept of buffering local anesthetics.

Answers for this exercise must be received by October 31, 2016.

  1. Nociceptors are specialized _______ nerves that are responsible for detecting painful stimuli.

    A. sensory
    B. motor
    C. parasympathetic
    D. sympathetic

  2. Intracellular _________ channel receptors are blocked by local anesthetic molecules to prevent conduction of nerve impulses.

    A. calcium
    B. sodium
    C. potassium
    D. hydrogen

  3. Uncharged local anesthetic molecules can readily pass through the nerve cell membrane into the nociceptor to reach their intended targets and block intended receptors. Charged local anesthetic molecules are able to cross the cell membrane into the neuron, but are unable to block receptors.

    A. Both statements are true.
    B. The first statement is true; the second is false.
    C. The first statement is false; the second is true.
    D. Both statements are false.

  4. Vasoconstrictors prolong anesthesia by _______________.

    A. affecting intracellular channel receptors
    B. changing the charge of the local anesthetic molecules
    C. reducing blood flow to the injection area
    D. stimulating the central nervous system to increase the heart rate

  5. The pKa of lidocaine is ________.

    A. 7.5
    B. 7.6
    C. 7.7
    D. 7.8

  6. The local anesthetic solution in which anesthetic molecules are dissolved is basic. If the pH of the anesthetic solution is raised, more molecules are available to cross into the nerve cell.

    A. Both statements are true.
    B. The first statement is true; the second is false.
    C. The first statement is false; the second is true.
    D. Both statements are false.

  7. Buffering anesthetic solution is theoretically effective at reducing pain because it _________.

    A. reduces physical trauma at injection site mucosa
    B. raises the temperature of the anesthetic solution
    C. decreases the acidity of the anesthetic solution
    D. improves blood flow of the injection area

  8. How is the stability of epinephrine affected when the buffered local anesthetic solution is prepared at manufacturing rather than at chairside?

    A. Stability is increased.
    B. Stability is decreased.
    C. Stability is unaffected.
    D. The buffered solution cannot be prepared chairside.

  9. Onpharma’s Onset uses ______________ to buffer local anesthetics.

    A. sodium bicarbonate
    B. sodium citrate
    C. potassium bicarbonate
    D. potassium citrate

  10. Which of the following injection techniques was used for this study?

    A. inferior alveolar nerve block
    B. periodontal ligament infiltration
    C. greater palatine nerve block
    D. infraorbital nerve block

  11. The buffered solution was administered with a _______ needle.

    A. 27-gauge long
    B. 27-gauge short
    C. 30-gauge short
    D. 30-gauge extrashort

  12. How much time (in minutes) was allowed to elapse after the 20% topical benzocaine was applied prior to injection?

    A. 1
    B. 2
    C. 3
    D. 4

  13. The administration of the anesthetic solution occurred over _____ seconds total in the 2 administration techniques.

    A. 20
    B. 40
    C. 60
    D. 80

  14. Malamed et al conducted a study in which the buffered anesthetic solution was administered over ______ seconds.

    A. 20
    B. 40
    C. 60
    D. 80

  15. All of the following may be affected by buffering of local anesthetics except one. Which is the exception?

    A. pH of anesthetic solution
    B. rate of anesthetic onset
    C. perceived pain of anesthetic injection
    D. duration of anesthesia


Please respond to the statements below, using the following scale:
1 Poor; 2 Below average; 3 Average; 4 Above average; 5 Excellent

Practicality of the content 1 2 3 4 5
Benefit to your clinical practice 1 2 3 4 5
Quality of illustrations 1 2 3 4 5
Clarity of objectives 1 2 3 4 5
Clarity of exercise questions 1 2 3 4 5
Relevance of exercise questions 1 2 3 4 5
Did this exercise achieve its objectives? Yes No
Did this article present new information? Yes No
How much time did it take you to complete this exercise? mins

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