local anaesthesia used in dentistery ppt

local anaesthesia used in dentistery ppt

1. LOCAL ANAESTHESIA Presented by House Officer Htet Myat Aung 30.5.2024 5/28/24 1

2. CONTENTS DEFINITION PROPERTIES CLASSIFICATION COMPOSITION TECHNIQUES MAXILLARY INJECTION TECH MANDIBULAR INJECTION TECH SUPPLEMENTAL INJECTION TECHNIQUES COMPLICATIONS LOCAL SYSTEMIC CONCLUSION 5/28/24 2

3. DEFINITION Loss of sensation in a circumscribed area of the body caused by depression of excitation in nerve endings or inhibition of the conduction process in peripheral nerves. Important feature: produces this loss of sensation without inducing loss of consciousness Major differentiating factor from general anaesthesia. 5/28/24 3

4. PROPERTIES OF LOCAL ANESTHETICS Should not irritate the tissue to which it is applied Should not cause permanent alteration of nerve structure Low systemic toxicity Must be effective regardless of mode of administration Time of onset should be as short as possible Duration of action must be long enough to permit completion of the procedure but not as long as to require extended period of recovery. It should have sufficient potency to give complete anaesthesia without using harmful concentrates Relatively non-allergenic Should be stable in solution Should readily undergo biotransformation in the body Should be sterile or capable of sterilization by heat without deterioration. 5/28/24 4

5. CLASSIFICATION OF LOCAL ANAESTHETICS Based on Pharmacology TYPE OF DRUG EXAMPLES ESTERS Esters of benzoic acid BUTACAINE COCAINE BENZOCAINE TETRACAINE Esters of para-amino benzoic acid CHLOROPROCAINE PROCAINE AMIDES ARTICAINE BUPIVACAINE DIBUCAINE LIDOCAINE PRILOCAINE QUINOLINE CENTBUCRIDINE 5/28/24 5

6. B. Based on Mode of Application TOPICAL INJECTABLE SOLUBLE INSOLUBLE COCAINE LIDOCAINE TETRACAINE BENZOCAINE BUTYL AMINO-BENZOATE LIDOCAINE MEPIVACAINE TETRACAINE BUPIVACAINE DIBUCAINE 5/28/24 6

7. C. Based on duration of action ULTRA SHORT PULPAL <10 min CHLORPROCAINE PROCAINE SOFT TISSUE 30-45 min SHORT PULPAL 5-10 min LIDOCAINE PRILOCAINE SOFT TISSUE 60-120 min MEDIUM PULPAL 45-90 min MEPIVACAINE ATRICAINE SOFT TISSUE 120-240 min LONG PULPAL 90-180 min BUPIVACAINE ETIDOCAINE SOFT TISSUE 240-540 min 5/28/24 7

8. D. Based on potency of the drug LOW INTERMEDIATE HIGH PROCAINE CHLORPROCAINE LIDOCAINE MEPIVACAINE TETRACAINE BUPIVACAINE DIBUCAINE 5/28/24 8

9. COMPOSITION OF LA VASOCONSTRICTORS IN LA: Decrease blood flow to the site of inj →better visualisation Slows down absorption of LA into CVS → lower anaesthetic blood levels Reduced systemic toxicity More LA enters into nerve → remains longer → incr. duration of action 5/28/24 9

10. TECHNIQUES OF LOCAL anaesthesia A.LOCAL INFILTRATION -Small terminal nerve endings in the area of treatment -Flooded with local anaesthetic solution -Incision made into same area into which solution is deposited INDICATION: management of isolated areas. B.FIELD BLOCK -Local anaesthetic solution deposited near larger terminal nerve branches -Anesthetized area is circumscribed to prevent passage of impulses from the tooth to the CNS -Incision made into area away from the site of injection of the anaesthetic solution INDICATION: 2-3 adjacent teeth are involved. C.NERVE BLOCK -Local anaesthetic is deposited close to a main nerve trunk, usually at a distance from the site of intervention e.g., PSA, IANB, nasopalatine nerve block, etc. INDICATION: pain control in quadrant dentistry. 5/28/24 10

11. MAXILLARY INJECTION TECHNIQUES SUPRAPERIOSTEAL INJECTION Most frequently employed local anaesthetic technique Used to achieve pulpal anaesthesia in maxillary teeth Require numerous tissue penetrations– require greater volume of anaesthetic solution INDICATIONS: Pulpal anaesthesia of 1-2 maxillary teeth Soft tissue anaesthesia for surgical procedures in a circumscribed area CONTRAINDICATIONS: (i) Infection or acute inflammation in the area of injection (ii) Dense bone covering the apices of teeth High success rate Atraumatic Not suitable for large areas. 5/28/24 11

12. The syringe should be held parallel with the long axis of the tooth and inserted at the height of the mucobuccal fold over the tooth 5/28/24 12

13. B. POSTERIOR SUPERIOR ALVEOLAR NERVE BLOCK Used to anesthetize the pulpal tissue, corresponding alveolar bone, and buccal gingival tissue to the maxillary first , second , and third molars. INDICATIONS: involves 2 or more maxillary molars When supraperiosteal inj is contraindicated (e.g., infection or acute inflammation) Supraperiosteal injection has proven ineffective CONTRAINDICATION: when the risk of hemorrhage is too great (e.g., in haemophiliacs) 5/28/24 13

14. Technique • Area of insertion- height of mucobuccal fold between 1st and 2nd molar • Angle at 45° superiorly and medially • No resistance should be felt (if bony contact angle is to medial, reposition laterally) Insert about 15-20mm Aspirate then inject if negative 5/28/24 14

15. C. MIDDLE SUPERIOR ALVEOLAR BLOCK Used to anesthetize the maxillary premolars, corresponding alveolus, and buccal gingival tissue Used if the infraorbital block fails to anesthetize premolars INDICATION: Dental procedure involving both maxillary premolars only CONTRAINDICATIONS: Infection or inflammation in area to be injected Absence of MSA nerve 5/28/24 15

16. D. Anterior superior alveolar nerve block: Used to anesthetize the maxillary canine, lateral incisor, central incisor, alveolus, and buccal gingiva Technique: Area of insertion is height of mucobuccal fold in area of lateral incisor and canine Insert around 10-15mm 5/28/24 16

17. E. Infraorbital nerve block : Used to anesthetize the maxillary 1 st and 2 nd premolars, canine, lateral incisor, central incisor, corresponding alveolar bone, and buccal gingiva – Combines MSA and ASA blocks – Will also cause anesthesia to the lower eyelid, lateral aspect of nasal skin tissue, and skin of infraorbital region Technique: • Palpate infraorbital foramen extra-orally and place thumb or index finger on region Retract the upper lip and buccal mucosa Area of insertion is the mucobuccal fold of the 1 premolar/canine area Contact bone in infraorbital region Inject 0.9-1.2cc of local anesthetic 5/28/24 17

18. PALATAL ANAESTHESIA GREATER PALATINE NERVE BLOCK Can be used to anesthetize the palatal soft tissue of the teeth posterior to the maxillary canine and corresponding alveolus/hard palate INDICATIONS: When palatal soft tissue anaesthesia is necessary Pain control during periodontal surgical procedures involving the palatal soft and hard tissues CONTRAINDICATIONS: Inflammation or infection at injection site Smaller areas of therapy (1-2 teeth) 5/28/24 18

19. B. NASOPALATINE NERVE BLOCK Minimizes need for multiple palatal injections Potentially HIGHLY TRAUMATIC 2 approaches: Single-needle penetration of palate at the incisive foramen Multiple-needle penetration of: Labial frenum in midline Interdental papilla between 11, 21 Palatal soft tissues lateral to incisive papilla INDICATIONS: similar to greater palatine nerve block CONTRAINDICATIONS: inflammation and smaller area of therapy 5/28/24 19

20. C. LOCAL INFILTRATION OF THE PALATE Nerves anesthetized: terminal branches of Nasopalatine n. and Greater palatine n. Soft tissue anesthesia Acceptable haemostasis when a vasoconstrictor is used Minimum area of numbness Potentially traumatic. INDICATIONS: Haemostasis during periodontal surgical procedures Palatogingival pain control on limited areas of anesthesia CONTRAINDICATIONS: Inflammation or infection at injection site Pain control for more than 2 teeth Area anesthetized by a palatal infiltration 5/28/24 20

21. MANDIBULAR INJECTION TECHNIQUES INFERIOR ALVEOLAR NERVE BLOCK Especially useful for quadrant dentistry Rarely indicated bilaterally High rate of inadequate anaesthesia (31-81%) Complications include: soft tissue trauma INDICATIONS: Procedures involving multiple teeth in one quadrant When buccal & lingual soft tissue anaesthesia is necessary CONTRAINDICATIONS: Infection or acute inflammation in the area of injection (rare) Pt. more likely to bite tongue/lip e.g., young children or mental/physical handicap patient 5/28/24 21

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23. B. BUCCAL NERVE BLOCK SOLELY INDICATED in manipulation of buccal soft tissues of mandibular molars e.g., with scaling or curettage Also known as LONG BUCCAL n.b. Extremely high success rate (100%) Readily accessible location; easily administered INDICATION: dental procedures requiring anesthesia of involved region CONTRAINDICATION: infection or acute inflammation in the area of injection 5/28/24 23

24. MANDIBULAR NERVE BLOCK: GOW -GATES TECHNIQUE Dr. George Gow-Gates, Australia (1973) High success rate (99%) True mandibular nerve block: provides sensory anaesthesia to ENTIRE DISTRIBUTION of V 3 ADVANTAGES REQUIRES ONLY ONE INJECTION Few post-injection complications Provides successful anaesthesia in case of bifid IAN and bifid mandibular canals DISADVANTAGES Lingual and lower lip anaesthesia– uncomfortable for many patients Longer time of onset (5 min) as compared to IANB (3-5 min) INDICATIONS Multiple procedures on mandibular teeth Buccal soft tissue anaesthesia required from mandibular third molar to midline Lingual soft tissue anaesthesia required Unsuccessful conventional IANB CONTRAINDICATIONS Infection or acute inflammation in the area of injection Patients with history of lip biting, e.g., young children, physical/mental handicap Patients unable to open their mouth wide 5/28/24 24

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26. VAZIRANI- AKINOSI CLOSED MOUTH MANDIBULAR BLOCK TECHNIQUE VAZIRANI, 1960 | Joseph AKINOSI, 1977 For limited mandibular opening – patient need not be able to open the mouth Fewer post-op complications reported Potentially traumatic if needle is too close to the periosteum Areas anesthetized: Mandibular teeth to the midline Body of mandible and inferior portion of the ramus Buccal mucoperiosteum and mucous membrane in front of the mental foramen Anterior 2/3 rd of tongue and floor of oral cavity (lingual n.) Lingual soft tissues and periosteum 5/28/24 26

27. a. Area anesthetized by a Vazirani-Akinosi closed-mouth mandibular nerve block b. Barrel of syringe is held parallel to maxillary occlusal plane with the needle at the level of mucogingival junction of 2 nd or 3 rd max. molar 5/28/24 27

28. C. MENTAL NERVE BLOCK Very little indication for most dental procedures Primarily used for: buccal soft tissue procedures e.g., suturing of incisions High success rate: easily accessible COMPLICATIONS: Hematoma (bluish discoloration and tissue swelling at injection site) Paraesthesia of lip/chin – gives sensation of an “electric shock” on contact with needle 5/28/24 28

29. D. INCISIVE NERVE BLOCK Not necessary when IANB or mandibular nerve block is successful Lingual soft tissue anaesthesia not achievable Area anesthetized: Buccal mucous membrane anterior to mental foramen (2 nd premolar to midline) Lower lip and skin of the chin Pulpal nerve fibres to premolars, canine and incisors INDICATIONS: when IANB is not indicated – when 6,8 or 10 anterior teeth are to be treated CONTRAINDICATION: infection or acute inflammation 5/28/24 29

30. SUPPLEMENTAL INJECTION TECHNIQUES INTRAOSSEOUS (IO) anaesthesia Involves the deposition of local anaesthetic solution into cancellous bone that supports the teeth. Modifications of IO anesthesia commonly used in periodontics – PDL INJECTION STA- INTRALIGAMENTARY INJECTION INTRASEPTAL INJECTION 5/28/24 30

31. PERIODONTAL LIGAMENT INJECTION Aka peridental injection (1912-1923) Devices used – Peripress, Ligmaject ADVANTAGES: Avoid unnecessary areas of anesthesia Minimizes dosage of anaesthetic Supplements partially effective block DISADVANTAGES: Administration difficult in some areas May cause post-op discomfort, tooth extrusion, &/or tissue necrosis Excess pressure may break cartridge INDICATIONS: Anesthesia for 1-2 teeth Bilateral mandibular treatment needed Isolated treatment in children Nerve blocks contraindicated (in haemophiliacs) Aid diagnosis of mandibular pain CONTRAINDICATIONS: Primary teeth Infection/inflammation Psychological need for “feeling numb” 5/28/24 31

32. B. STA – INTRALIGAMENTARY (PDL) INJECTION - single-tooth anesthesia Avoid nerve blocks Immediate onset with profound anesthesia Accurate and precise delivery of local anaesthetic solution Eliminate collateral numbing of lip, cheek and tongue Consistent reduction in patient pain perception DISADVANTAGE: technique-sensitive; expensive 5/28/24 32

33. C. INTRASEPTAL INJECTION Anaesthesia of bone, soft tissue and root structure at injection site INDICATIONS: when both pain control and haemostasis are required for soft tissue and osseous periodontal tx CONTRAINDICATIONS: Infection/ inflammation Area of insertion Angle of insertion Area anesthetized 5/28/24 33

34. D. INTRAOSSEOUS INJECTION Technique for mandibular infiltration Perforate the cortical plate to introduce local anaesthetic solution to the medullary bone Bathes the periradicular region in LA ADVANTAGES: Lack of lip and tongue anesthesia Atraumatic Immediate onset Few post-op complications DISADVANTAGES: Technique-sensitive Bitter taste of LA Occasional difficulty in placing needle in pre-drilled holes (mandib. 2 nd – 3 rd molar) Increased palpitations when vasopressor containing LA is used 5/28/24 34

35. COMPLICATIONS ASSOCIATED WITH LOCAL ANAESTHESIA LOCAL Needle breakage Pain on injection Burning on injection Persistent anaesthesia or paraesthesia Trismus Hematoma Infection Edema Sloughing of tissues Lip chewing Facial nerve paralysis Post-anaesthetic intraoral lesions SYSTEMIC Toxicity (due to LA and VC) General NS toxicity Cardiovascular toxicity Drug interactions Allergic effects Syncope 5/28/24 35

36. CONCLUSION Local anesthesia remains the foundation of pain control in dentistry, especially when combined with moderate-deep sedation for invasive and painful procedures in contemporary periodontal surgery. Local anaesthetics remain the safest and most effective drugs in dentistry to relieve intra- and post-operative pain. It is only with a thorough understanding of the pharmacological actions and anatomy that periodontists can have a basic clinical foundation to enhance patient care. 5/28/24 36

37. REFERENCES MALAMED’s Handbook of Local Anaesthesia, 6 th edition NETTER’s Clinical Anatomy, 4 th edition Wikimediacommons.com 5/28/24 37

38. THANK YOU 5/28/24 38