Clinical Correlations Anesthetics Flashcards
What are the common topical anesthetics used in dentistry?
• Benzocaine (18-20%): Rapid onset (15-20 sec), duration (10-15 min), inexpensive.
• Oraqix (Dentsply): Onset (30 sec), duration (20 min), gels at body temperature.
Name the most commonly used injectable local anesthetics in dentistry.
- Lidocaine (Xylocaine)
- Articaine (Septocaine, Carticaine)
- Mepivacaine (Polocaine, Carbocaine)
- Bupivacaine (Marcaine)
What is the significance of epinephrine in anesthetics?
• Extends duration of anesthesia.
• Decreases bleeding by vasoconstriction.
• Must be limited in patients with severe cardiac disease (2 carpules max of 1:100,000 Lidocaine).
What are the different concentrations of Lidocaine used in dentistry?
• 2% Lidocaine, 1:100,000 Epinephrine (standard).
• 2% Lidocaine, 1:50,000 Epinephrine (for increased hemostasis).
What anesthetic has the longest duration and is used for long procedures?
• Bupivacaine (Marcaine) 0.5% with 1:200,000 epinephrine.
What are the maximum carpule limits for local anesthetics?
• 13 carpules of Lidocaine 2% with 1:100,000 epi.
• 10 carpules of Lidocaine 2% with 1:50,000 epi.
• 7 carpules of Mepivacaine 3% (no epi), Mepivacaine 2% with 1:20,000 levonordefrin, Bupivacaine 0.5% with 1:200,000 epi, or Septocaine 4% with 1:100,000 or 1:200,000 epi.
Which anesthetic is contraindicated for children under 4 years old due to increased risk of paresthesia?
• Articaine (Septocaine, 4%)
What are the major nerve blocks used in dentistry?
- Inferior Alveolar Nerve Block (IANB) - Mandibular teeth on the side of injection.
- Gow-Gates Block - Entire mandibular division.
- Incisive (Mental) Block - Mandibular premolars and anteriors.
- Posterior Superior Alveolar (PSA) Block - Maxillary molars (except MB root of 1st molar).
- Nasopalatine Nerve Block - Six maxillary anterior teeth.
- Greater Palatine Nerve Block - Palatal gingiva of posterior maxillary teeth.
What is a hot tooth, and why is it difficult to anesthetize?
• A severely inflamed vital tooth with moderate to severe spontaneous pain.
• Resistance to local anesthesia due to:
• Lower tissue pH (less anesthetic dissociation).
• Increased blood flow.
• Central sensitization of nociceptors.
What are the alternative injection techniques for supplemental anesthesia?
• Intrapulpal injection: Very painful, immediate effect but short duration (15-20 min).
• Intraligamental injection: Small volume, localized effect, duration ~23 min.
• Intraosseous injection: Fast onset, short duration (15-30 min).
How does infection affect local anesthesia effectiveness?
• Increased acidity reduces anesthetic dissociation, leading to poor anesthesia.
• Nerve blocks are more effective than infiltration in these cases.
What is the recommended anesthetic protocol for surgery requiring prolonged anesthesia?
• 2 carpules of 2% Lidocaine 1:50,000 epi.
• 1 carpule of 0.5% Marcaine 1:200,000 epi per quadrant.
What are anesthetic concerns in systemic diseases?
• Severe cardiac disease: Limit epinephrine to 2 carpules (1:100,000).
• Hypertension: Vasoconstrictors help prevent catecholamine release.
• Hyperthyroidism: Avoid excessive epinephrine (risk of tachycardia, dysrhythmias).
• Diabetes Mellitus: Poorly controlled diabetics may be more prone to hyperglycemia with vasoconstrictors.
What factors influence a patient’s reaction to local anesthesia?
• Anxiety and sleeplessness.
• Traumatic dental history.
• Severe inflammation (reduces anesthetic efficacy).
What is the painless dental injection technique?
• Controlled flow rate and pressure during injection.
• More comfort, less anxiety, increased patient satisfaction.
• Devices like X-Tip, Stabident can improve delivery.
