Mechanism of Action of Local Anesthesia

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What factor affects the onset of action of a local anesthetic used in oral surgery?

The amount of drug removed by local blood vessels

Proximity to the target nerve (correct)

Duration of action

Type of vasoconstrictor added

Why are vasoconstrictors added to local anesthetics for oral surgery?

To prolong the duration by dampening the effects of local vessels on drug removal (correct)

To speed up the onset of action

To reduce the amount of drug deposited

To increase the pH of the solution

Which anesthesia lasts a shorter time: pulpal anesthesia of maxillary teeth after local infiltration or pulpal anesthesia of mandibular teeth after block anesthesia?

Maxillary teeth after local infiltration (correct)

Mandibular teeth after block anesthesia

There is no difference in duration

Both last for the same duration

How does the amount of drug deposited affect the duration of action of a local anesthetic?

More drug deposited leads to longer duration Signup and view all the answers

What is the role of vascularity of tissue in the duration of action of a local anesthetic?

Low vascularity prolongs duration Signup and view all the answers

Why does pulpal anesthesia disappear earlier than soft tissue anesthesia in some cases?

Deposition closer to soft tissues than to pulp Signup and view all the answers

What is the purpose of local anesthesia in dentistry?

To block the function of sensory nerves Signup and view all the answers

Why is it optimal to limit the number of different forms of a drug used by those administering local anesthesia?

To master the use of a specific category of drug Signup and view all the answers

In local anesthesia, which ions are allowed to shift across the nerve membrane upon depolarization?

Sodium ions Signup and view all the answers

How does local anesthesia affect motor nerves?

It inhibits their function Signup and view all the answers

What is a paradoxical effect in relation to drug reactions?

An opposite outcome of a drug occurs Signup and view all the answers

What is the main goal in properly performing oral surgery on an awake patient?

To provide profound local anesthesia Signup and view all the answers

What is the primary mechanism of action of local anesthetics?

Raising the membrane firing threshold for electric impulse propagation Signup and view all the answers

At what pH do local anesthetics without vasoconstrictors typically work best?

pH 6.5 Signup and view all the answers

Why do manufacturers lower the pH of local anesthetics when adding vasoconstrictive agents like epinephrine?

To inhibit oxidation of the vasoconstrictor Signup and view all the answers

What effect does local anesthetic pH have on its effectiveness when injected into an area of inflammation/infection?

It becomes less effective Signup and view all the answers

How do local anesthetics primarily affect nerve membranes to prevent impulse conduction?

Maintaining a depolarized state Signup and view all the answers

What factor influences the speed of onset and duration of action of local anesthetics?

Their lipid solubility Signup and view all the answers