lecture4Analgesic in dentistry college of Yemen .pptx

Analgesic in dentistry college of Yemen

1. ORAL SURGERY Dr. Faisal Abulahom

2. Lec.4 Methods and Techniques Local anesthesia

3. Methods and Techniques Local anesthesia Methods of producing local anesthesia : 1 - By refrigerant effect: Application of cold in any form as by the use of ice boxes crushed ice or application of volatile liquid to the area, the use of ethyl-chloride spray with lower temperature of the tissues and cause analgesia of the part .

4. This acts by two ways direct on the main nerve trunk supplying the area and depriving the nerve including the nerve tissues from its blood supply. Both the direct pressure and the local ischemia block the nerve condition, This principle is practically applied to the limbs by means of Smirch ’ s bandage Apparently this method has no place in the oral cavity 2-Application of pressure

5. 3-The use of drugs: Local anesthesia can be produced by many drugs, but only few can suppress the function of the sensory nerves without injury to the surrounding tissues.   Phenol : When applied in 5% solution to a wound it will damage all form of protoplasm including the protoplasm of the nerve cells this produce preliminary irritation followed by light superficial anesthesia , this mean that phenol has no specific action on the nerve tissue Quinine : Is anther general protoplasmic poisoning likes phenol. When applied in a certain concentration it can act as a local anesthesia with selective action on a nerve tissue only.

6. 1 – It must produce efficient anesthetic action. 2 - It should have a rapid onset of anesthesia of reasonable duration. 3 - It must have a selective action on sensory nerves . 4 - The reaction with the nerves tissues must be reversible For particle application an ideal local anesthetic drug should have certain properties and characteristics, which are:

7. 5- It should be soluble in water so that it can be used in solution for injection in order to diffuse into the tissue and nerve fibers. 6 - It must be compatible with the salts used to form the in isotonic solution. 7 - Non-irritating to the tissues, should not produce local secondary effects such as hyperemia, inflammation or necrosis. 8 - Can be sterilized without deterioration or loss of action. 9 - should have no effect on the healing process of the tissues..

8. 10 - Should have no systemic side effect after its absorption . 11 - Should have vasoconstrictor action, if not, it should be compatible with adrenaline or its substitutes. 12 - Its chemical composition must be stable and can be stored for a considerable time.    13 - Should not be expensive .

9. b-physical means as by cold application to the area.   Techniques of local anesthesia in an area without loss of consciousness. Local anesthesia is a local and temporary state of insensibility This is achieved by several means: a- mechanical means as by the use of pressure on the main nerve trunk supplying the area.

10. c- chemical means due to the action of a chemical compound deposited in the vicinity of the nerve or nerves supplying the area. Local anesthesia can be produced by the action of the local anesthesia agent. On either the free nerve ending, the terminal nerve endings in the area of the surgery or the main nerve trunk supplying this area.

11. Kinds of local anesthesia 1- Topical anesthesia 2 - Infiltration anesthesia a- Soft tissue infiltration b- Bony tissue infiltration 3 - Nerve block anesthesia

12. . . The application of ointments or solutions containing local anesthesia compounds to accessible structures . Skin and mucous membrane is called topical anesthesia, in such condition the anesthetic agent penetrates through the epithelium and renders the area. . Topical anesthesia is useful as it permits the painless insertion sharp needles and also for simple's superficial procedures. 1 - Topical anesthesia

13. 2 - Infiltration anesthesia Is achiever when the terminal nerve ending supplying the operative area are Flooded by the diffusion of the injected anesthesia solution rendering them incapable of becoming stimulated Here two kinds could be differentiated:

14. a - Soft tissue infiltration This is achieved in the oral cavity by sub mucosal injections or Paraperiosteal injection. In performing sub mucosal injections the needle is inserted beneath the mucosal layer and the solution is deposited and then diffuses in that particular plane in performing sub- periosteal injections, the needle should be inserted till it contacts the periosteum this is known as the needle meets resistance and no attempt should be made to force the needle farther towards bone.

15. as the solution is deposited, it will diffuse through the periosteum and the adjacent bony plate. No trial should be made to use sub periosteal injections for infiltration anesthesia because of: 1- The liability of needle breakage and severe pain to the patient if the whole bevel of the needle has to be inserted between the periosteum and the bone. 2- the difficulty of forcing the anesthetic solution between the periosteum and the bone.

16. b- Bony tissue infiltration It is also called intraosseous injection. In this technique the bony cortex is penetrated and the anesthesia solution is injected into the cancelli of the bone where, by diffusion. The needle should not be forced into bony structures, but a path way should be made by a suitable instrument, dental bur, before inserting the needle.

17. 3- Nerve block anesthesia The anesthetic solution is deposited extraneurally or paraneurally in close proximitly to the main nerve trunk supplying the operative area . An accessible point along its course to the periphery of the region.