Pain Control in Operative Dentistry-dharam

7/28/2019 Pain Control in Operative Dentistry-dharam

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PAIN CONTROL IN OPERATIVE DENTISTRY

A quickened pulse rate, a hastened heart beat, clammy, sweaty skin,

thirsty dry mouth, a tightness in the gut and a feeling in the mind Do we

really have to do this.

Hold on, control your imagination, all Im describing is an attack of

dental anxiety, phobia and pain.

Good morning and welcome to todays seminar on pain control in

operative dentistry.

Lets confabulate on this under the following topics:

Introduction

Definition and etiology of pain

Methods of pain control

Latest advances

Conclusion

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INTRODUCTION

Since ancient times, the profession of dentistry has been associated

with excruciating trauma and unbearable discomfort. Vivid imagery and

exaggerated cartoonery depicted dentists as the epitome of satanic devils

ready to inflict merciless agony. So much so, that pain become

synonymous with dentistry and dentistry with pain. However, the era of

modern dentistry decided to shun this image and made rapid strides in

changing the perception of dentistry from a heartless monster to a caring

angel. Various advances in anesthetics, operating techniques and clinical

ambience and approach have shown the way towards truly painless

dentistry.

Definition What is painPain is defined as an unpleasant sensory and emotional experience

resulting from a stimulus causing, or likely to cause, tissue damage or

expressed in terms of that damage. This is affected by emotional factors.

Various assessments are used to evaluate pain like the linear and

visual analog scale, Minnesotta Multiphasic Personality Index (MMPS)

and other subjective and objective criteria.

Now, lets have a look at the various possible causative factors for

pain in operative dentistry.

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1) Firstly the patient Pain being a highly subjective and

individualistic response, the patient plays a major role in how much

pain is felt. Stoic, controlled patients may bear even the most

unpleasant procedures quietly while highly hysteric patients might

jump even if you dont touch them. Hence, patient conditioning is

such an integral and vital part of pain management.

2) Second are the instruments, materials and armamentarium used in

dentistry rotary instrumentation, caustic chemicals, improperly

handled hand instruments and ironically the anesthetic needle itself

are associated with pain responses. Heat and pressure play an

important role in these mechanisms.

3) The Pulp- Dentin Organ Enamel is sensationless. Any procedure

performed purely on enamel is incapable of causing pain. However,

procedures that involve the dentin and pulp elicit only pain as a

response; if any. The various theories of pain transmission of pain in

dentin and pulp are still exploring the exact cause but sensitivity is

an integral part of the dentinal response.

4) Improper handling of tissues Careless and insensitive handling of

the oral tissues may result in operative or post operative discomfort

and pain. Hence, delicate management of oral tissues is a must.

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Now we come to the methods or techniques of pain control:

These can be broadly described under

1) Gaining the confidence of the patient.

2) Ideal instrumentation and proper implementation.

3) Use of cooling devices.

4) Use of palliative drugs and obtundants.

5) Dessication of dentin.

6) Pressure anesthesia with cocaine.

7) Local anesthesia.

8) Use of inhalation sedation or nitrous oxide sedation

9) Hypnosis and psychotherapy.

10)General anesthetics.

1) Gaining the confidence of the patient: The first axiom is Treat the

individual, not just the tooth. A patient is an individual just like us

with his / her own complexes, beliefs and fears. The correct

psychological approach will help us not only to understand their

needs but also alleviate any apprehension skillfully.

Individual personality of the dentist and the right demeanour can

have a profound influence on patient confidence and reduction of

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anxiety with subsequently reduced perception of pain. The art and

science of skillful conversation should be mastered to create a warm

and lasting relationship.

Succinct yet thorough explanation of the involved procedures with

required modalities to accommodate age related understanding goes

a long way in achieving patient cooperation.

Also important is the look and feel of the workplace. The ambience

of the operatory, the care manifested in minor detailing and the

entire interior the sights,smells and sounds should convey a warm,

caring message to soothe the patient.

Every procedure and action should be performed confidently to give

the impression of efficiency and instill a sense of security in the

patient.

All these measures can indeed make the experience highly

rewarding for the individual and the clinician.

2) Correct instrumentation: Instrumentation can be either

Hand cutting

Rotary instrumentation Slow speed or High speed.

Hand cutting instruments:

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The main principle of cutting with hand instruments is to concentrate force

in a very thin cross section of the instrument at the cutting edge. Therefore,

the thinner the cross section, the more sharper the instrument and hence the

more efficient it is.

Dull or blunt instruments require more pressure to cut the tooth structure

which also causes more frictional heat thus eliciting pain.

It has been shown that when a force of 10 lbs is applied on a sharp edged

instrument, the cutting efficiency is equal to 200lbs whereas in a dull edged

instrument it falls down to 20lbs.

Thus sharpening stones should be used to always maintain sharp

instruments resulting in efficient work and lesser trauma.

Rotary instruments: Rotary instrumentation can govern the presence or

absence of pain through

1) Speed 2) Pressure 3) Heat production and 4) Vibration all of which

are inter related.

a) Low speed instruments such as micromotor and other devices

results in

(Ultra low 300-3000rpm, low 3000-6000 rpm, medium

20,000-45,000, high 45,000-1,00,000, ultrahigh 1,00,000 and

more).

1. Application of more pressure on the cutting surface.

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2. Increase in the vibration which is 2 fold in origin

i.e., amplitude and undesirable modulating

frequency.

At low speed, amplitude is increased and frequency

is decreased.

3. Because of the friction, there is more heat

production which is also directly proportional to

pressure, revolutions per minute and area of tooth in

contact because if any of these factors are increased,

heat production increases which can cause damage

to the pulp if temperatures reach 130F though even

110-113F can produce inflammatory responses.

To overcome the disadvantages of low speed, high and ultrahigh speed

instrumentation was introduced into dentistry. These rotate at speeds above

45,000 to 1,50,000 rpm and more and their advantages include:

1) Efficient rapid cutting.

2) Convenient to operator and patient.

3) Minimal vibration.

4) Low frictional heat with coolants.

5) Longevity of cutting instruments.

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6) Less pressure and sensitivity low speed (25lb), high speed (1lb),

ultrahigh (1-4 ounces).

Disadvantages:

1. Overcutting.

2. Visibility is hampered.

3. Lesser tactile sensation.

A major advancement with high speed cutting was the introduction of

coolants to lower the frictional heat and enhance efficiency and comfort.

3) Use of cooling devices: Coolants minimize pain and maximize

efficiency with high speed. The commonly used coolants are:

a) Air.

b) Water.

c) Combination of both which is the most popular and highly

effective.

Also, the use of chilled burs is said to diminish pain. CO2 and ethyl

chloride have also been experimented with.

4) Use of Obtundants: Here, soothing and palliative type of cements or

medicaments are used on dentin.

Desensitizing agents like ZnCl2, Ag(NO3)2, Ferric oxalates can minimize

dentinal sensitivity.

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Commonly used obtundant is ZOE which can be placed over cut dentin as

an intermediate dressing in patients having severe sensitivity.

Also in cases like cracked tooth syndrome a band is cemented around the

tooth with ZOE where it acts as an obtundant as well as a cementing

medium.

5) Dessication of dentin:

Previously, a school of thought advocated that dessication or drying of

dentin by a blast of warm air gives relief from sensitivity and

subsequent pain.

However, recent school of thought states that over dessication should

be avoided so as to prevent the fluid movement inside the dentinal

tubules, which causes pain, as hypothetized by the hydrodynamic

theory.

Even during cavity cleansing, a 3-way syringe should be used taking

advantage of both air and water.

6) Pressure anesthesia with cocaine:

This method is particularly effective in anesthetizing the pulp of

deciduous and young permanent teeth but not effective in areas of

secondary dentin and carious areas. It is quite effective for a short

duration procedure.

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The solution used has the following ingredients as elucidated by

Stanley W. Clark.

a) Cocaine 25%

b) Ether 10%

c) Chlorophenol 15%

d) Alcohol 50%.

Technique:

Access should be gained to the dentin cutting through enamel with a 1mm

inverted cone bur.

The opening is enlarged, changing it to the form of a section of a conewith

the larger end at the surface.

A very small bit of cotton pledget (1mm) should be moistened with the

solution and placed at the bottom of the opening.

A slightly larger piece of unvulcanized rubber should then be placed over

the cotton and pressure, at first light and gradually increased to heavy is

applied in a series of thrusts using a round, flat faced condenser about 1 to

2mm in diameter.

This forces the solution through the dentinal tubules to anesthetize the

pulp.

This must be done in a dry field.

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7) Local Anesthesia: It is the most widely used and popular technique

of effective pain control

8) . It is defined as a transient regional loss of sensation to a painful or

potentially painful stimulus resulting from a reversible interruption

of peripheral conduction along a specific neural pathway to its

central integration and perception in the brain.

Cavity preparation and Endodontic procedures may be painlessly

carried out after securing anesthesia by infiltrating the apical tissues or

by nerve blocking with one of the LA solutions.

It reduces pain as well as permits the dentists to work faster and save

time.

One should operate just as carefully when preparing cavities in teeth

with anesthetized pulps as though they are not anesthetized.

Local anesthesia administration should be monitored by performing a

preanesthetic evaluation.

Any history of allergies, cardiac anomalies, anemia or other blood

dyscrasias, kidney, liver or thyroid problems, infectious diseases,

epilepsy, bleeding disorders, diabetic complications or psychiatric

disturbances should be noted and adequate provisions or preparations

made for their handling.

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The various local anesthetics used are basically of ester and amine type.

Though choice mainly depends on situation and dentist, lignocaine with

a vasoconstrictor, specifically adrenaline is the most popular anesthetic

of choice. The vasoconstrictor aids in prolonging the action of the

anesthetic. The average duration of pulpal anesthesia obtained with

vasoconstrictor is approximately 1 hour while it is just 5-10 minutes

without vasoconstrictor.

Another important consideration is preparedness for any medical

emergencies. Anesthetic toxicity, allergic reactions, syncope,

hyperventilation etc are all contingencies for which an average

practitioner should be equipped and emergency drugs should be

available at hand. Proper preparation and precautions will make local

anesthesia a safe and predictable pain control procedure.

LA techniques:

1. Local infiltration (supraperiosteal infiltration)

Supraperiosteal anesthesia is described as a technique in

which anesthetic is deposited into the area of treatment (0.6-

0.9ml).

Small terminal nerve fibres in the area are blocked and thus

rendered incapable of transmitting impulses.

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This is commonly employed in maxillary teeth because of the

ability of anesthetic solutions to diffuse through periosteum and

relatively thin cancellous bone.

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2. Regional nerve block:

Nerve block is defined as a method of achieving regional

anesthesia by depositing a suitable local anesthetic solution close

to a main nerve trunk, preventing afferent impulses from

traveling centrally beyond that point.

i) Maxillary anesthesia Maxillary nerves that can

be anesthetized include the PSA, the anterior

superior alveolar, greater palatine, the

nasopalatine and the second division of the

trigeminal.

PSA block, also called as the zygomatic or tuberosity

block, is indicated when pulpal anesthesia is required

for the maxillary third, second and first molars (except

mesiobuccal root of 1st molar) with the underlying

buccal alveolar process, periosteum, connective tissue

and mucous membrane also being anesthetized.

Infraorbital nerve block produces anesthesia of anterior

superior alveolar and middle superior alveolar providing

anesthesia for central and lateral incisors, canines and

premolar.

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Greater (anterior) palatine nerve block provides

anesthesia to both the hard and soft tissues ranging from

the 3rd molar as far anterior to as the first premolar. In

the region of first premolar, partial anesthesia may be

encountered as branches of the nasopalatine nerve

overlap.

Nasopalatine nerves enter the palate through the incisive

foramina, located in the midline just palatal to the

central incisors and directly beneath the incisive papilla,

which anesthetize the premaxilla as far distal as the first

premolar.

Palatal anesthesias are often traumatic because of the

density of the palatal soft tissues and their firm

attachment to bone. So, it is advisable to use topical

anesthesia before palatal injections.

Maxillary or second division nerve block-

Though rarely necessary, it should be considered when other techniques

prove inadequate because of infection accompanied by inflammation.

This block provides anesthesia of the entire maxillary nerve peripheral to

the site of injection, pulp of all maxillary teeth on the side of injection,

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buccal soft tissues and bone; hard palate on the injected side, upper lip,

cheek, side of the nose and lower eyelid.

2) Mandibular anesthesia Mandibular pulpal anesthesia is normally

achieved through the inferior alveolar nerve block. Additionally,

anesthesia of the buccal soft tissues and bone anterior to the

mandibular molars is provided.

The lingual nerve is usually anesthetized along with the inferior

alveolar nerve. It provides anesthesia in the anterior 2/3 rd of the tongue,

the floor of the oral cavity and the mucous membrane and

mucoperiosteum on the lingual side of the mandible.

A successful inferior alveolar and lingual nerve block provides

anesthesia to all mandibular tissues except the buccal mucous

membrane and mucoperiosteum over the molars. To achieve anesthesia

of this region, the buccal nerve block must be administered.

Incisive or mental nerve block: The incisive and mental nerves are

terminal branches of the inferior alveolar nerve, arising at the mental

foramen.

This provides sensory innervation to the skin of the lower lip and chin

and the mucous membrane lining the lower lip, also, the incisive nerve

remaining within the mandibular canal provides sensory innervation to

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the pulps of premolars, canine and incisors and the bone anterior to the

mental foramen.

Mandibular nerve block: A true mandibular block injection provides

adequate anesthesia of all sensory portions of the mandibular nerve

(buccal, inferior alveolar, lingual and mylohyoid). This can be achieved

through the Gow Gates techniques involving the lateral side of the neck

of the mandibular condyle below the insertion of the lateral pterygoid

muscle.

Akinosi or closed mouth technique: This is indicated when opening of

the mandible is limited owing to infection, trauma or trismus.

Additional local anesthetic techniques:

1) Periodontal ligament injection:

The PDL injection is frequently used when isolated areas of inadequate

anesthesia are present. It is also indicated to achieve anesthesia in a

single mandibular and / or maxillary tooth.

Advantages include adequate pulpal anesthesia with a minimal volume

of solution (0.2-0.4ml) and absence of lingual and lower lip anesthesia.

2) Intraseptal infiltration (variation of intraosseous) Here the 27-

gauge 1-inch needle is inserted into the interseptal tissue in the area

to be anesthetized. Its success rate is not so high. It is relatively

more successful in young patients due to decreased bone density.

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3) Intrapulpal injections Though rarely indicated in operative

procedures, intrapulpal technique may be used to achieve pain

control when pulp chamber of a tooth is exposed.

The needle is firmly wedged into the canal to a snug fit and the solution

administered under pressure.

4) Intraosseous injection Though rarely employed since the

acceptance of the PDL injection, the intraosseous injection can be

effective in producing anesthesia adequate to permit certain

operative procedures.

To administer an intraosseous injection, the dentist must anesthetize the

soft tissues and bone overlying the apical region of the tooth through

local infiltration.

Effect of Local Anesthetics on the pulp:

A special consideration here must be given to the action of local anesthetic

with a vasoconstrictor on the health of the pulp organ.

The purpose of adding a vasoconstrictor to LA is to potentiate and prolong

the anesthetic effect by reducing the blood flow in the area to which it is

administered.

However, at the same time it causes a significant decrease in pulpal blood

flow although the flow reduction lasts a relatively short time.

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There is a direct relationship between the length of flow cessation and the

concentration of the vasoconstrictor used. Increased concentration of

epinephrine causes a longer cessation of pulpal blood flow.

Researchers have reported that pulpal blood flow returned to normal levels

after 3 hours of total cessation of blood flow.

Presumably, irreversible pulp damage resulting from tooth preparation is

caused by the release of substantial amounts of vasoactive agents

(substance P) into the extracellular compartment of the underlying pulp.

Under normal circumstances, these vasoactive substances are quickly

removed from pulp by the blood stream but when blood flow is decreased

these substances are accumulated along with other metabolic waste

products thus damaging the pulp.

Therefore wherever possible, it is advisable to use vasoconstrictor free LA

for restorative procedures on vital teeth.

9) Inhalation or Conscious Sedation:

Conscious sedation and inhalational analgesia are now accepted

modalities of pain control. Various pharmacotherapeutic agents have

been advocated. Myriad chemicals that have been proposed are

barbiturates, psychosedative drugs like phenothiazine derivatives,

propyl alcohol derivatives, benzodiazepine derivatives, and narcotics

like morphine but the most popular and widely used is nitrous oxide

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and oxygen inhalational analgesia. This technique basically relies on

elevation of pain threshold.

Nitrous oxide and oxygen in a controlled combination produce highly

effective sedation. Concentrations of 35-40% produce enhanced

sedative effects and are the recommended concentrations and produce

its peak effect in 3-5 minutes. Being inert, it does not combine with any

body tissue and is eliminated unchanged through the lungs is less than 5

minutes. However, the use of this technique requires elaborate

equipment and care during administration.

10)Hypnosis and psychotherapy Hypnosis is a sleep-like state with

persistence of certain behavioral responses. The subject is

susceptible to and may respond to the hypnotic suggestions

concerning aspects of behavior, environment, memory etc. It has

been used in various modalities in medicine and dentistry to alter

responses to pain. It is currently used to define an area of research

and treatment that employs suggestion. The long history of hypnosis

with various contributions is testimony to its effectiveness.

Combined with other techniques, it is a powerful tool.

The dentist and the patient may derive certain benefits:

The dentist has the opportunity to work on a more relaxed and

cooperative patient while the patient is less fatigued with no specific

recollection of having experienced discomfort. The operation must have

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a through knowledge of the mechanics of hypnosis and the associated

psychological, emotional and mental factors as well as the principles

associated with hypnosis. Posthypnotic suggestion has also been

proposed as a way of alleviating certain noxious dental habits.

Other psychological techniques include psychotherapy, operant

conditioning, biofeedback, systematic deconditioning and relaxation

techniques.

Biofeedback deserves mention as an interesting adjunct to pain control.

Its principal aim is the control and regulation of disordered nervous

system behavior. The therapeutic applications usually translate to the

direct control and elimination of the symptom. Hirschman and

coworkers reported success in lowering dental phobia and pain

perception and anxiety levels with a procedure that used forearm

extensor EMG biofeedback during dental treatment. Its mastery and

effectiveness await further research and trials.

11) General anesthesia: This technique involves complete transient

reversible of consciousness. Various agents like ether, halothane,

Fentanyl with Domperidone etc are utilized. It is employed as the

last report and this finds rare application in dental pain control. The

various stages of anesthesia as described by Guedal is 1957 are:

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Stage I Analgesia.

Stage II Excitement.

Stage III Surgical anesthesia

Plane I

Plane II

Plane III

Plane IV

Stage IV Overdose

General anesthesia is a highly specialized field and requires the

assistance of medical specialists and preparatory equipment.

Preanesthetic evaluation and medication have to be charted into the

treatment plan. Its use is reserved for highly demanding cases.

Role of medication in pre and postoperative pain control:

Most of the patients suffering from pulpitis are likely to have been

taking oral analgesics. NSAIDS can be used to control patient

discomfort postoperatively or preoperatively as well as for possible

placebo effect. Their myriad range from acetylsalicylates to ibuprofen,

and the latest COX-2 inhibitors afford a huge array of medicaments to

choose from.

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Advances and Newer concepts in pain control:

1) Newer, better acting local anesthetics with fewer side effects and

better safety profile like confbuinidine and repivacaine may change

the pharmaceutical range of anesthetics used in future. Also

alterations to local anesthetic profile like EMLA (Eutectic mixture

of local anesthetics) which allows profound topical anesthesia and

pH alteration to make administration more comfortable as well as

hyaluronidase to permit better penetration are but a few of the

research modalities.

2) Electronic dental anesthesia The use of electricity as a therapeutic

modality is not really new dating back to 40 A.D. but momentum in

this field gathered since the 1960s when TENS was introduced into

medicine and EDA was proposed for dentistry.

The mechanics differs for chronic and acute pain. Basically low

frequency setting of 2Hz and higher frequency of 120Hz for chronic

and acute pain is used which produces changes in blood serotonins, L-

tryptophan, endorphins, and enkephalins. Also the gate control theory is

employed upon for acute pain control.

In dentistry, it has found applications in Myofacial pain dysfunction

syndrome, acute dental pain for restorative and prosthetic procedures,

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adjunct to local anesthesia and as an aid in its administration and

reversal of LA.

It is basically administered with use of electrodes. Low frequency of

2.5Hz for 40-60 minutes is used for chronic pain while high frequency

of 120Hz is employed for restorative procedures adjusting the

controller and maintaining the electronic pad positions for various teeth

and procedures.

At present, it is basically indicated as an adjunct to local anesthesia and

future prediction for use in all spheres of dentistry exists. It is

contraindicated in cardiac pacemaker patients, neurological disorders,

pregnancy, maturity etc.

While advantages of no needle or infection exist the cost, training and

experimental nature of the modality are the drawbacks. Presently

available systems include Cedata, H-wave and 3M patient comfort

system. Only future research will show which way this technique

progresses.

3) Alternative tooth preparation These include the modality of air

abrasion, lasers, ultrasonics and chemomechanical means. Air

abrasion utilizes micron sized particles to remove tooth structure. It

is relatively more comfortable but has the disadvantage of lack of

control and has not caught the popular imagination. Lasers are now

available for hard tissue lasing and are reported as painless,

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noiseless and highly patient friendly. However, it is still under

research and the cost too is highly prohibitive.

4) A new treatment modality that promises to revolutionize the way we

look at operative dentistry also promises to eliminate pain

completely. This involves the use of ozone as a means to sanitize

carious lesions and employ remineralization techniques to

regenerate tooth structure with minimal, if any, restorative

procedures. Kavos Healozone is a novel, experimental device under

trial. Only time will tell, if it will deliver on it promises.

Newer techniques and ideas are being constantly researched upon to

achieve the ideal.

CONCLUSION:

No pain, no gain, goes the old axiom; however, it can be modified in

modern dentistry to state no pain, all gain. The application of ideal

techniques and procedures with expertise and an attitude of empathy and

understanding will help the clinician control and eliminate this highly

unwelcome stimulus to achieve greater efficiency and highly contented

individuals. Remember, to the whole world you might just be one man,

but to one man you just might be the whole world. That one man is the

individual who comes to us for relief-OUR PATIENT.

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BIBLIOGRAPHY

1) Local anesthesia and pain control in Dental practice Monheim.

2) Anesthesia A to Z Yentis, Hirsch, Smith.

3) Handbook of local anesthesia Stanley Malamed.

4) Sturdevants art and science of operative dentistry.

5) Operative Dentistry Marzouk.

6) DCNA Anesthesia in dentistry April 1999.

7) DCNA Dental Phobia and Anxiety October 1988.

8) Operative dentistry by G.V. Black.

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Documents

Pain Control in Operative Dentistry-dharam