بسم الله الرحمن الرحيم بسم الله الرحمن الرحيم

Pain control in operative procedure Dr. Emad Farhan Alkhalidi PhD conservative dentistry

Pain is one of the most commonly symptoms in dentistry.

Pain: is unpleasant sensory or emotional experience associated with actual or potential tissue damage.

Pain can be described as sharp, burning, aching, cramping, dull or throbbing as human emotions.

Recognition of irritant to the tooth gives the patient an opportunistic to correct the problem before irreversible effect can occur

this recognition occur because of pain receptors in the pulpodentinal complex are linked to the CNS by afferent pathway.

Electrophysiology of nerve conduction:

In unstimulated nerve (nerve membrane in a polarized state), a nerve possesses a resting potential (-ve electrical potential of -70 mv)

in this state interior of the nerve is –ve relative to the exterior (Na+ outside & K+ inside the nerve membrane).

When a stimulus is applied to the nerve the nerve membrane, alter its permeability that permit Na+ to diffuse through membrane into nerve cell &

passage of K+ out side (depolarization of the membrane from its resting level to its threshold potential or firing threshold (+ 40 mv),

in this state interior of the nerve is +ve relative to the exterior in this state interior of the nerve is +ve relative to the exterior. The entire depolarization process requires 0.3msec..

After depolarization, the repolarization will be occurred After depolarization, the repolarization will be occurred. The permeability of the nerve membrane again decrease and K+ move toward outside nerve cell

and restoring original electrochemical equilibrium -70 mv

Referred pain The sensation is interpreted as coming from one area ,although it actually originates elsewhere; thus the pain of angina pectoris is often felt in the left arm

Pain and Anxiety Control Local anesthesia – the elimination of sensations, especially pain, in one part of the body by the topical application or regional injection of a drug Analgesia – The diminution or elimination of pain in the conscious patient

Local Anesthesia Uses: 1- To eliminate pain. 2-To reduce salivation. How we can obtain effective anesthesia ? Thorough Knowledge of patient anatomy, physical and emotional status. Understanding the effect of drug ,Adv. &disadv. Of adding vasoconstrictor.

Mechanism of Action of Local anesthesia Local anaesthetic agents occupy Na+ channels and inhibit the rapid passage of Na+ ions and the propagation of the wave. These events are complex and not fully understood.

Local anesthetics inhibit the excitatory changes which result in nerve conduction. LA binds to a receptor on the sodium channel, inhibiting the channel's function so that no sodium current is generated, thereby blocking nerve impulses.

Therapeutic dose: Overdose: Is the smallest amount of drug that is effective when properly administered and does not cause adverse reaction. Overdose: Is an excessive amount that result in a local accumulation or elevation of blood level of drug which cause adverse reaction. 5-8 cartilage / Appo. (for normal healthy patient) Each 1.8 ml contain 2% lidocain either with or without Adrenalin 1:100,000 MRD of 2% lidocain is 4.4 mg/kg

Patient condition and L.A. C.V.S. (blood pressure, heart rate) eg. Systolic pressure more than 200& diastolic more than 115 should not receive invasive, elective dental treatment untile BP reduced. Resting patient with pulse rate less than 60 or more than 110 should be questioned further. Overdose of any vasoconstrictor cause increase BP ,heart rate and possible dysrhythmia ( retraction cord treated with adrenalin in abraded gingiva)

C.N.S. More easily affected than C.V.S. Minimum or moderate overdose cause: Depression, apprehension, sweating, elevated BP., heart rate, respiratory rate, drowsiness Moderate to high overdose cause: Tonic –Clonic activity followed by generalized C.N.S. depression decrease BP., Heart rate (less than 60 beat/min.), respiratory rate, and respiratory arrest. Allergy to L.A. is contraindicated to injection cause Anaphylactic shock

Benefit of Local anesthesia 1- Patient cooperation. 2- Salivation control. 3- Hemostasis (vasoconstrictor). 4- Operator efficiency.

Injection site for infiltration Technique

Hypnosis: To control fear of pain from dental procedure. Cause: relaxation and cooperation of patient . In certain circumstances it is useful in combination with L.A. to reduce anxiety and apprehension.

Thank you