Local anaesthesia

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Introduction to Endodontics
Forth Year

Published in: Health & Medicine

Local anaesthesia

  1. 1. RADIOGRAPHS IN ENDODONTICS AND LOCAL ANAESTHETICS
  2. 2. LOCAL ANAESTHESIA IN ENDODONTICS
  3. 3. FACTORS AFFECTING ENDODONTIC ANAESTHESIA 1. Apprehension and anxiety:  Patients emotional status  Psychologically distraught patient may have low pain threshold.  Fear of unknown 2. Fatigue: lack of sleep inability to eat Decreased ability to manage stress
  4. 4. 3. Tissue inflammation: Allodynia – a tissue that is inflamed is more sensitive to stimulus. 4. Previous unsuccessful anaesthesia : Patient giving a previous history of failed anaesthesia will be more anxious and prove more difficult to manage - psychological management - supplemental anaesthesia
  5. 5. INITIAL MANAGEMENT Psychologic approach: Involves 4 C‟s – Control : obtained by maintaining an upper hand Communication : listening to the patient explaining the treatment procedure and outcomes Concern: by letting the patient know that your are being aware of the patients concerns Confidence: exhibiting a positive body language especially during diagnosis and treatment
  6. 6. Painless injections : Master injection techniques – minimum pain during injection • Obtaining patient confidence • Topical anaesthetic : place a small amount on the dried mucosa for 1 to 2mins 20% lidocaine patch placed on the mucosa for about 5 mins. • Solution warming : though popularly followed , may not make much difference. • Needle insertion : gentle insertion in the right angulation and at the right site
  7. 7. • Small- gauge needles: 27 gauge needles are most suitable for conventional dental injections • Slow injection : Slow injection decreases the tissue pressure built up and also the patient discomfort. Computer controlled anaesthetic delivery system
  8. 8. The device delivers 1.4ml of solution over 4 mins 45 secs The system is NOT PAINLESS Two stage injection: Initial slow administration of the anaesthetic solution under the mucosal surface - after initial numbness – going deep and administering the solution at the required depth. Gender differences in pain: Women react more to pain than men
  9. 9. Is anaesthesia required during all the steps ???????? “YES” Adjunctive pharmacologic therapy: Sedation : Inhalational/ Oral/ Intravenous
  10. 10. CONVENTIONAL ANESTHESIA MANDIBULAR ANAESTHESIA [INFERIOR ALVEOLAR/ MANDIBULAR NERVE BLOCK]
  11. 11. Anaesthetic agents: • Most commonly used 2% Lidocaine with 1: 100,000 avoided or used with caution in patients with cardiovascular diseases Factors related to anaesthesia: • Lip numbness: usually occurs 5-7 mins after the IANB Does not usually indicate pulpal anaesthesia • Onset of pulpal anaesthesia: may usually occur in 10 – 15mins • Duration: if successful, the pulpal anaesthesia may remain for 2-2 ½ hrs
  12. 12. Altering the Anaesthesia: • Increasing the volume : may not increase the success rate of pulpal anaesthesia • Increasing the epinephrine concentration: May not increase the success rate of IANB • Alternative solutions : • 2% Mepivacaine with 1: 20,000 levonordefrin • 4% Prilocaine with 1: 200,000 epinephrine • 3% Mepivacaine • 4% Prilocaine Without epinephrine
  13. 13. Alternative techniques for mandibular anaesthesia Gow-Gates technique : Needle is directed towards the neck of condyle.
  14. 14. Vizarani- Akinosi technique : closed mouth technique
  15. 15. Mental Nerve Block : effective for the Premolars Infiltration injections : may not be effective for pulpal anaesthesia
  16. 16. LONG BUCCAL NERVE BLOCK
  17. 17. Maxillary Nerve Block Posterior Superior Alveolar Nerve Block Posterior teeth till the maxillary first molar
  18. 18. Middle Superior alveolar nerve block
  19. 19. Infra orbital Nerve Block Can be used to anaesthetize the canines , premolars and incisors
  20. 20. PALATAL ANAESTHESIA NASOPALATINE NERVE BLOCK GREATER PALATINE NERVE BLOCK
  21. 21.  WHENEVER ENDODONTIC TREATMENT IS TO BE PERFORMED IN TEETH WITH A PALATAL ROOT - PALATAL ANAESTHESIA SHOULD BE GIVEN IN ADDITION TO THE CONVENTIONAL MAXILLARY BLOCKS/INFILTRATIONS
  22. 22. Local Infiltration Found to be most effective in Maxillary teeth Altering the Anaesthesia: • Volume : for maxillary infiltration increase in the volume increases the duration • Alternative solutions: Unlike the mandibular blocks, long acting anaesthetic solutions do not provide prolonged anaesthesia with maxillary infiltrations
  23. 23. Anaesthesia Difficulties: Patient reports all the classic signs of anaesthesia but still has pain Maybe due to 1. Anaesthetic solution not penetrating to the sensory nerves of the pulp 2. Central core theory : Nerves on the outside of the bundle supply the molars while those in the inside supply the anteriors . Hence IANB may not be sufficient for anterior teeth. 3. Local tissue change due to inflammation: LA is basic in nature and the inflammation produces an acidic pH . So the LA’s are not very effective in inflammed tissues 4. Hyperalgesia : inflamed tissues have decreased excitability threshold hence are more reactive 5. Apprehensive patient 6. Insufficient time for the LA to act
  24. 24. Supplemental anaesthesia Indications: • Used when the routine /standard injections are not effective • Absence of „classic signs‟ should be considered for repeating the injection/block • If the symptoms are present but still there is pulpal pain then re-injection will not be effective
  25. 25. INTRAOSSEOUS ANAESTHESIA • Involves deposition of the LA directly into the cancellous bone adjacent to the involved tooth • Used in conjunction with regular anaesthesia. • Utilizes a IO system which has two components a) Slow speed hand piece driven perforator : drills a small hole through the cortical plate b) 27 gauge ultra short injector needle : to deliver the LA solution into the cancellous bone
  26. 26. STABIDENT
  27. 27.  Perforator breakage : can be easily removed with a haemostat  Injection discomfort : Normally there is minimal pain  Selection of the perforation site : Distal perforation and injection would afford best anaesthesia. Except Second molars  Anaesthetic agents: conventional agents  Onset of anaesthesia : mostly rapid  Success : high success rates  Failure: inability to perforate , change the location
  28. 28. Post operative problems: • Less than 5% of patients will develop local inflammation / swelling. • This is mostly due to overheating of bone during the perforation Systemic effects: Same as those of conventional anaesthesia Vasoconstrictor causes tachycardia Medical contraindication: Vasoconstrictor avoided in patients with CVS disorders 3% mepivacaine plain is preferred
  29. 29. INTRALIGAMENTARY / PDL INJECTION It involves the delivery of LA agent into the periodontal ligament space. Approximately 0.2 ml of LA agent is deposited into the PDL space using a 30/27/25 gauge needle. The needle is inserted into the gingival sulcus at 30 degrees angulation to the long axis of the tooth; at the mid root position mesially and distally.
  30. 30. The anaesthetic solution should be delivered against resistance / back pressure
  31. 31. • Mechanism of action : The PDL injection forces the LA through cribriform plate → marrow spaces → vasculature in and around the tooth
  32. 32. • Injection discomfort : most of the times it is painful, unless used secondary to conventional LA • Onset of anaesthesia: is mostly rapid • Success: good success rates • Duration of anaesthesia: approximately 10-20 mins • Postoperative discomfort: usually seen due to the damage during needle insertion
  33. 33. INTRAPULPAL ANAESTHESIA Involves administration of LA agent into the pulp tissue after /during access opening. Main disadvantages → extremely painful → very short duration of action → pulp must be exposed Advantage → rapid and predictable onset
  34. 34. IRREVERSIBLE PULPITIS CONVENTIONAL ANAESTHESIA CLASSIC SYMPTOMS COLD TEST/ ELECTRIC PULP TEST PAIN CONVENTIONAL ANAESTHESIA + INTRA OSSEOUS/ + PDL PAIN INTRA PULPAL NO PAIN
  35. 35. ANAESTHESIA FOR SURGICAL PROCEDURES INCISION AND DRAINAGE • Whenever swellings are encountered , before incision and drainage, LA should not be administered into the swelling • This causes an increase in pressure within the swollen tissue and also the LA is ineffective due to rapid absorption
  36. 36. PERIRADICULAR SURGERY Conventional anaesthesia - Nerve block + Local infiltrations • Use of Long acting Local anaesthetic agents is recommended for surgical procedures

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