Conservative Dentistry PDF

## دكتور: محمد الفقهي ### **Chapter 1** **Importance of Proper Operating Position** * **Patient**: * Comfortable * Relaxed * Less muscular tension * More capable to cooperate with the dentist * **Operator**: * Less physical strains * Less fatigue * Better vision * Un...

## دكتور: محمد الفقهي ### **Chapter 1** **Importance of Proper Operating Position** * **Patient**: * Comfortable * Relaxed * Less muscular tension * More capable to cooperate with the dentist * **Operator**: * Less physical strains * Less fatigue * Better vision * Unnecessary dentist to patient contact reduced * Possibility of developing musculo-skeletal problems reduced **Positions of the Operator** * **Most restorative dental procedures can be completed while the operator is seated.** * **When standing** : * Proper balance and weight distribution on both feet is essential. * **When sitting**: * Both feet should rest on the floor. * **In both positions (standing and sitting)**: * Back and chest should be in an upright position with the shoulders squared. * **Positions that create unnecessary curvature of the spines and collapsing the shoulders should be avoided.** * If certain circumstances prevent maintaining this position, uncomfortable or unnatural positions that produce undue strain on the body should be used only rarely. **Positions of the Dental Chair** * **Chair and patient position is an important consideration.** * **Most modern dental chairs are designed to provide total body support and patient comfort at any chair position.** * **Chair design and adjustment can provide a maximal operator access to the working area.** * **A contoured or lounge-type chair provides complete patient support and comfort.** * **An adjustable headrest cushion or articulating headrest also should be available.** * **Adjustment control switches should be conveniently located.** * **Some chair designs provide a foot adjustment switches to improve the infection control.** ### **Patient Reception, Dismissal & Operating Positions** **Patient Position**: * **The patient should have a direct access to the chair.** * **Height of the chair should be low.** * **Backrest should be upright and the right armrest should return to normal position after the patient is seated.** * **The headrest should be adjusted for head support and the chin should be elevated slightly from the chest.** * **The chair position should provide minimal neck muscles strain and facilitate swallowing.** **The most common chair position**: * **Supine or reclined position.** * **The choice of patient position differs with the 1) operator, 2) procedure type and 3) working area in the mouth.** * **In the supine position, the patient head, knees and feet are approximately in the same level.** * **The patient head should not be lower than the feet.** **When operator operates in the maxillary arch**: * **The occlusal surfaces of the upper teeth should be oriented nearly perpendicular to the floor.** **When the operator works in the mandibular teeth**: * **The occlusal surfaces of the mandibular teeth should be oriented nearly 45 degrees to the floor.** * **The operator should not hesitate to rotate the patient head backward, forward or from side to side to accommodate proper access and visibility of the working area.** ### **The Operating Positions** * **The operating position is defined as "the location of the operator or the location of the operator's arm in relation to the patient position."** **For the right-handed operator**: * **Three essential positions**: * **Right front or 7-O'clock position** * **Direct right or 9-O'clock position** * **Right rear or 11-O'clock position** **For the left-handed operator**: * **Three essential positions**: * **Right front or 5-O'clock position** * **Direct left or 3-O'clock position** * **Left rear or 1-O'clock position** * **A fourth position, direct or 12-O'clock position has applications in certain areas in the mouth** (Fig. 1-7). * **All of these positions can be used from the standing or seating positions of the operator.** * **Teeth to be treated should be at the same level of the operator's elbow.** * **In long-standing operative work, the changing between operating positions from time to time can provide certain amount of rest and muscle relaxation.** 1. **The right front position (Left front)**: * **The operator is standing or seating in from the patient head on the right side (Fig. 1-7).** * **This position facilitates examination and work on mandibular anterior teeth, mandibular posterior teeth especially in the right side (left mandibular teeth for the left-handed operator) and the upper maxillary teeth (Fig. 1-8).** * **It is convenient to slightly rotate the patient head toward the operator for better visibility.** 2. **The direct right position (Direct left)**: * **The operator is standing or seating directly to the right (or left) of the patient head (Fig. 1-7).** * **This position is convenient for working in the buccal surfaces of the right maxillary and mandibular teeth or buccal surfaces of the left maxillary and mandibular teeth for the left-handed operator and the occlusal surfaces of the right posterior mandibular teeth or occlusal surfaces of the left mandibular posterior teeth for left-handed operators (Fig. 1-9).** 3. **The right rear position (Left rear)**: * **The operator is in the right and behind the patient head or left and behind in case of left-handed operators (Fig. 1-7).** * **This position is convenient for the direct and indirect vision for most areas in the mouth.** * **The lingual surfaces of the upper anterior teeth and the occlusal surfaces of the upper posterior teeth are viewed indirectly in the mouth.** * **The occlusal surfaces of the mandibular teeth are viewed directly and the mouth mirror is used for reflection of light and soft tissue retraction (Fig. 1-10).** 4. **The direct rear position**: * **The operator is standing or seating directly behind the head of the patient (Fig. 1-7).** * **This position may have limited applications and is used mainly for working in the lingual surfaces of the mandibular anterior teeth (Fig. 1-11).** **Patient Dismissal** * **When the patient is completed, the chair should be returned to the upright position (zero position) and the right rest-arm is adjusted, so the patient can leave the chair easily and prevent undue strain or loss of balance.** ### **PATIENT ASSESSMENT, EXAMINATION, DIAGNOSIS, TREATMENT** **Introduction** * **For proper treatment planning we must do the followings**: * **Proper infection control.** * **Over view of the patient including**: * **Printed questionnaire for personal and medical history.** * **Review of medical history.** * **Clinical examination of oro-facial soft tissues followed by examination of dental caries and other teeth problems including erosion and abrasion, then examination of previous restorations.** **Patient assessment** * **General data**: * **Patient full name.** * **Address and telephone number**: * **To postpone the appointment if needed and to send him a bill of fees.** * **Age**: * **Gives an idea about**: * **Size of the pulp.** * **The position of the gingival attachment.** * **The depth of the cavity and the biological principles.** * **Sex**: * **Certain diseases are related to specific sex, e.g. gingival enlargement during pregnancy and menstruation.** * **Occupation**: * **Gives an idea about certain occupational defects**, e.g. notches in anterior teeth of dressmakers and carpenters. * **Gives an idea about the material of choice for restoring a tooth.** * **Medical review**: * **This helps in identification of any condition that may alter, complicate or contraindicate the proposed dental procedures.** * **Certain systemic diseases may need consultation with specialist before starting treatment**, e.g. cardiac patient. * **Another condition needs hospitalization**, e.g. hemophilia. **Dental history**: * **Past dental history**: * **Frequency of dental treatment and problems were met during past interference, should be recorded.** * **Past dental experience for the same problem (Chief complaint) should be discussed with the patient in order to not to repeat disagreeable procedures.** * **Present dental history**: * **The patient's present problem (chief complaint) should be recorded in the chart.** * **The onset, duration and the related factors of the chief complaint should be recorded.** * **The date and type of available radiographs should be recorded to determine the need for additional radiograph and to minimize the patient exposure to necessary ionizing radiation.** **Examination and diagnosis** * **Examination**: * **The process of observing both normal and abnormal conditions.** * **Diagnosis**: * **The determination and judgment of variations from normal.** * **Signs outcomes of clinical examination and symptoms reasoning given by the patient.** * **Clinical examination procedures should be proceeded by review of the general oral condition and the type of occlusion using examination rubber gloves for all steps.** * **Paient asked to describe the various characteristics of pain (the onset and duration, stimuli theat causes pain, spontaneity, intensity, and factors that relieve pain).** *DR MOHAMED ELFOGHI* * **The incomplete fracture lines usually are found in teeth weakened by extensive caries or restorations.** * **It causes sharp pain when masticatory pressure is released.** * **If fracture involving pulp root canal treatment or extraction is required.** **Diagnosis of dental caries** * **Diagnosis of dental caries should include**: * **Determination of risk factors.** *DR MOHAMED ELFOGHI* **Clinical examination of dental caries** * **Risk factors predisposing for dental caries are either**: * **Non-oral factors including**: * **Age**, Sex, medical condition and general health, fluoride and genetic role. * **Oral factors including**: * **Tooth anatomy**, oral flora, oral hygiene, previous restorations and reduced salivation. * **Clinical examination of caries**: * **Visual examination**: * **Changes in texture and color of the tooth surface.** * **Cavitation.** * **Tactile**: * **catching with probe or explorer.** * **Radiographic**: * **radiolucent area appears in bite wing or periapical view.** * **Transillumination**: * **Dark area appeared when the tooth is subjected to fiber-optic light.** * **Digitizers**: * **Scanning usual radiographs.** * **Direct using R.V.G.** * **DIAGNOdent device.** * **Examination of caries in pits and fissures**: * **These are the most caries susceptible areas where the developmental lobes of calcification fail to coalesce.** * **Methods**: * **Discoloration and any changes in color by visual examination.** * **Probe catch by tactile examination.** * **Examination of caries in smooth proximal surfaces**: * **Visual examination**: * **Chalky appearance or shadow under the marginal ridge.** * **Observable cavitation in deep cavities.** * **Tactile examination**: * **By passing dental floss along side the proximal surface, tearing of dental floss fibers indicating caries.** * **Transillumination**: * **Dark cone in proximal surface in bite wing film is a true indicator for proximal caries.** *DR MOHAMED ELFOGHI* * **Examination of caries in smooth cervical surfaces**: * **Visual examination**: * **Chalky appearance of the cervical 1/3 may denote caries.** * **Disappearing-reappearing phenomenon, the chalky white appearance of carious lesion disappears with wetting and appears with dryness.** * **Tactile examination**: * **Sensitivity to probing.** * **Clincal situations for which radiographs may be be indicated**: * **Previous root canal or periodental therapy.** * **History of pain or trauma.** * **Large or deep restorations.** * **Swelling.** * **Fistula or sinus tract infection.** * **Mobility teeth.** * **Clinical evidence of periodental disease.** * **Unexplained sensitivity of teeth.** * **Unusual tooth color morhpology.** * **Clinical examination of amalgam restoration** * **Amalgam blues**: * **Bluish discoloration seen through enamel that may be due to**: * **Corrosive products leaching out from amalgam.** * **Amalgam seen through undermined enamel.** * **Amalgam overhangs**: * **Could be diagnosed by**: * **Visual**: * **buccal, lingual or occlusal overhangs.** * **Tactile**: * **using explorer.** * **Radiographic**: * **for proximal overhangs.** * **Dental floss**: * **threading of the floss when passed proximally.** * **Ditching**: * **Can be diagnosed visually or by probing which drops at the tooth/restoration interface.** * **When ditching is deep it can not be smoothened, amalgam should be replaced.** * *DR MOHAMED ELFOGHI.* * **Voids**: * **Represents surface discrepancies rather than ditches.** * **If more than 0.2 mm the restoration should be considered as defective one and should be replaced** * **Fracture line**: * **Using visual and tactile method, careful examination should be done to locate fracture line.** * **Amalgam should be replaced.** * **Improper anatomical contour**: * **When inadequate embrasure or misplaced contact area should consider the restoration is defective and should be replaced.** * **Marginal ridge discrepancy**: * **The proper position and height of marginal ridge should be inspected and compared with the neighboring tooth, other wise the restoration should be considered defective and replaced.** * **Proximal contact defects**: * **Using dental floss or passing light between the teeth may indicate the contact area relation of amalgam restoration.** * **Open contact or tight contact may lead to gingival and periodontal problems.** * **Recurrent caries**: * **Could be detected visually, tactile or radiographic as primary caries.** * *DR MOHAMED ELFOGHI* * **Clinical examination of cast restoration**: * **The same as amalgam restoration.** * **Clinical examination of esthetic restoration**: * **The same as amalgam in addition to discoloration.** * **Discoloration**: * **Should be observed whether marginal, surface or bulk type of discoloration and the restoration should be considered defective.** * *DR MOHAMED ELFOGHI* **** ### **ISOLATION OF OPERATIVE FIELD (CONTROL OF FLUIDS)** **Introduction**: * **The exclusion of moisture from the operative field and the production of an absolute dryness is an essentiality for the correct performance of most procedures in Operative Dentistry.** * **The presence of moisture is a handicap in many operations, with the exception of those or part of those, which involves the use of, mounted diamond abrasives, requiring a continuous stream of water, with latter exception, dryness of the operative field is a rule and mandatory.** **Reasons for Control**: * **Convenience and efficiency.** * **Visibility.** * **Best use of materials.** * **Asepsis.** **Conveniences and Efficiency**: * **Moisture control is required for the convenience of both the patient and the dentist.** * **Substantial quantities of water in the mouth are**: * **Unpleasant for the patient.** * **Make the work difficult for the dentist** * **Wasting the operator's time through the too much frequent expectoration.** * **Therefore Moisture control will**: * **Provides efficient dental work** * **Reduces the patient chair side time.** **Visibility:** * **The presence of water or saliva in the oral cavity usually obstructing vision and alter the reflective characteristics of the tooth surfaces during examination and operative procedures.** * **This problem must be overcome before delicate and accurate examination is performed by controlling of moisture that will help in getting and maintaining a better view of the operative field.** * **Moisture control will aid in**: * **A more thorough examination of the hard dental structures.** * **Better detection of dental caries in its initial clinically detectable grades.** * **Tooth debris during cavity preparation could be more easily detected and removed from the cavity, as it has not been plastered to the cavity walls and margins by moisture contamination** * **Etched enamel is more definitely revealed.** * **Cavity preparation could be more thoroughly revealed and examined for its mechanical and biological principles.** **Best use of materials**: * **Control of moisture during insertion of the currently available restorative materials, cements and cement bases and liners is mandatory.** * **This is because of**: * **It aids in getting better qualities, physical and chemical properties of these materials.** * **It protects some esthetic restorative materials as glass ionomer cements from moisture during its initial set.** * **Cement bases and liners are more successfully placed.** * **The seating of onlays could be more easily accomplished in a dry clean preparation.** * *DR MOHAMED ELFOGHI* **Asepsis**: * **Field isolation protects the patient from infection from possibly unclean instruments and the dentist from infection and diseases from unclean mouths.** **Methods of Control**: * **Several methods can be employed for controlling and isolating the field of operation**: * **Saliva ejectors and high volume evacuating equipment.** * **Absorbents** * **Compressed air** * **Rubber dam** * **Saliva ejectors & high-volume evacuating equipments**: * **They are differ primarily in the size of the tip that is placed in the mouth**: * **The former, with a diameter of 4 mm; the latter, with a diameter of 10 mm.** **Saliva ejectors**: * **Is used to aspirate saliva that collects in the floor of the mouth** * **It is quite unsuitable for dealing with large volume of water** * **Its tip must be smooth and made from a nonirritating material** * **The tip of the ejector should be designed to prevent the tissues from the floor of the mouth from being sucked.** * **Disposable, inexpensive plastic ejectors that may be shaped by bending with the fingers are available.** * **However, they are helpful and quite effective in providing short-term isolation and when absolute dryness is not required such as for**: * **Examination.** * **Polishing** * **Topical fluoride application** * *DR MOHAMED ELFOGH* **High-volume evacuating equipment**: * **It whisks away moisture and debris from the working area and controlling the comparatively large volume of water used by the high-speed hand piece (air-water spray) during cutting.** * **McWherter showed that one type of evacuator would remove 1 pint (0.5 L) of water in 2 seconds and 100% of solids during cutting procedures.** * **Ordinarily, it is operated by the dental assistant and the tip of the evacuator should be placed just posterior and as near as possible to the tooth being prepared.** **Absorbents**: * **As far as the use of absorbents is concerned, they have a limited practicability, and could only be used for a very short period of time with a certain degree of success.** * **In conjunction with profound anesthesia, such absorbents provide exceptional dryness over a long period of time as in case of**: * **Preparing for impression.** * **Cementing inlays or onlays.** * **Absorbents, such as**: * **Cotton rolls.** * **Cotton pellets.** * **Gauze pads 2" x 2".** * **Alpha cellulose wafers.** **Cotton rolls**: * **Come in a variety of lengths and sizes.** * **Two cotton rolls 1-1/2" long 3/8" in diameter, are the most popular.** * **The correct placement of the cotton rolls is in the vestibular space and opposite the exit of the salivary ducts.** * **Cotton rolls should not be placed in the midline because they are readily dislodged by the action of frenum attachment and tension from the lip muscles.** * **Naturally they must be changed frequently as they become saturated with saliva** **Cotton pellets**: * **In conjunction with cotton rolls, cotton pellets provide effective isolation if it is suitably placed in the proximal boxes of onlays preparation during their cementation.** **Gauze pads**: * **A piece of 2" x 2" gauze pad could be**: * **Tied around the tip of saliva ejector to prevent aspiration of the mucosa from the floor of the mouth.** * **Spread over the tongue and posterior part of the mouth to help in recovering the dropped polished inlay or onlay casting and prevent their swallowing if it slips onto the tongue that is moist during the try-in stage.** * **DR MOHAMED ELFOGHI** **Alpha cellulose wafers**: * **Manufactured in a number of sizes.** * **Generally triangular in shape with rounded corners** * **Inserted in the right or left vestibule** * **Effective in absorbing secretions from the parotid ducts** **Compressed air.** * **Air jet derived from air syringe are valuable in the control of moisture** * **Repeated use of air jet during the preparation provides effective dryness** * **It should be used just to ensure that the cavity is dry but not dehydrated** **Rubber dam.** * **Without any doubt, the rubber dam is the most effective way for controlling the field of operation.** * **Dr. Sanford C. Branum introduced it to the dental profession in 1864.** * **The goals achieved by rubber dam application are a combination of most of the goals achieved by all other isolation methods taken together. Sometimes it even exceeds these goals.** **Contraindications**: * **There are only limited occasions in which, its use is not indicated**: * **Young permanent teeth that have not erupted sufficiently to receive a retainer** * **Some third molar.** * **Occasionally some extremely mal-positioned teeth.** * **Patients suffering from asthma.** * **Patients cannot tolerate a rubber dam because of psychological reasons.** * **Sensitive patients with allergic reaction to rubber.** **Materials and Instruments needed for rubber dam application**: * **Rubber dam material** * **Rubber dam punch** * **Rubber dam clamps** * **Rubber dam clamp forceps** * **Rubber dam napkins** * **Lubricant** * **Dental floss** * **Modeling compound** * **Anchors other than clamps** * **Rubber dam holder** * **DR MOHAMED ELFOGHI** **Rubber dam material**: * **Is usually latex rubber.** * **It may be supplied in**: * **Rolls, 5 or 6 inches wide that may be cut to desired lengths.** * **Ready-cut dam material**: * **5" x 5" squares for children** * **6" x 6" squares for adults** **Types**: * **Depending on the thickness of the rubber dam material, it is classified into**: * **Thin (Light).** * **Medium.** * **Heavy.** * **Extra heavy.** * **Special extra heavy.** * **Thin or light weight dam (light color -0.15 mm)**: * **More easily applied and have the advantage of passing through the contacts easier.** * **More readily injured** * **Gives slight retraction to the oral soft tissues.** * **Adequate for endodontic therapy.** * **Medium weight dam (Blue color -0.20 mm)**: * **Not easily applied** * **Not more readily torn** * **Gives more retraction of compared with the thin one** * **More suitable to use with endodontic therapy** * **Heavy weight dam (Green color -0.25 mm)**: * **It is difficult to handle** * **Not easily torn** * **More effective in retracting tissues** * **More recommended for operative procedures** * **DR MOHAMED ELFOGHI** * **Extra heavy weight dam (Dark brown -0.30 mm)**: * **Also more difficult to handle** * **Not easily torn** * **Most suitable for operative procedure** * **It is more preferred for contrast** * **Special heavy weight dam (Black color -0.35 mm)**: * **It gives the maximum tissue retraction** * **More resistant to tearing** * **Especially recommended for isolating class V cavities in conjunction with a cervical retainer** **Rubber dam punch**: * **This instrument is used to cut the holes in the rubber dam** * **It has a tapered, sharp pointed lever type plunger and a rotatable metal disc with different sized holes.** * **Each hole is suitable to a special tooth.** **Helpful notes on punching and placement of the holes**: * **The proper size hole for the diameter of the tooth to be isolated should be matched and used.** * **The distance between holes should be comparable from the center of one tooth to the center of the adjacent tooth. Generally this is approximately 1/4 Inch (5.6 mm).** * **If the holes are placed too closely or incorrectly aligned → the dam will be stretched to the side permitting saliva to leak by.** * **If the holes are too far excessive rubber stock remains and is puckered between the teeth** * **When a cervical retainer is to be applied to isolate a class V lesion, the hole for the tooth should he punched facially to the arch form to compensate for the extension of the rubber.** * **In addition, the hole should be slightly larger, and the distance between it and the holes for the adjacent teeth should be slightly increased.** * **When the thinner gauges of rubber dam are used, smaller holes must be punched because the thin dam stretches more.** *DR MOHAMED ELFOGHI* **Rubber dam clamps**: * **For the rubber darn to be securely attached to the area being isolated, there are several devices (clamps) are available in a variety of sizes and shape depending on the type and the size of tooth to be clamped (Anchored tooth).** * **For this purpose, the clamp has to be used on the most posterior tooth of the field of operation.** * **Clamps are also used to retract gingival tissues.** **Parts of the clamp**: * **The clamp consists of**: * **Four blades or prongs.** * **Two jaws connected by a bow.** **Types of clamps**: * **According to the tooth attachment blades**: * **Four points contact blades.** * **Circumferential contact blades.** * *DR MOHAMED ELFOGHI* * **Four points contact blades**: * **Used with properly positioned tooth, where the four points contact the facial and lingual surfaces to prevent rocking or tilting of the clamp.** * **The prongs of some clamps are gingivally directed.** * **Circumferential contact blades**: * **The blades will contact the tooth surface evenly.** **Indications**: * **When the axial angles are lost or do not coincide with the corners of the four point contact clamps.** * **When the axial convexity of the tooth surface is sufficient for anchorage (fully erupted teeth).** **Disadvantage**: * **This type is less retentive, but it could also be less traumatic.** * **According to whether or not they have a dam engaging projection in their jaws**: * **Winged clamps.** * **Wingless clamps.** * *DR MOHAMED ELFOGHI* * **Winged clamps**: * **They can be attached to the rubber darn before application.** * **They are always bulkier than the wingless clamps.** * **Sometimes they cannot be used in last molars when the surrounding anatomy will not allow sufficient room for their placement** * **The wings often obstruct the application of a matrix retainer and other instruments while operating** * **Wingless clamps**: * **Most operator prefer the wingless clamps** * **According to the purpose of use**: * **Anchoring.** * **Retracting-anchoring.** * *DR MOHAMED ELFOGHI* * **Anchoring clamps**: * **Those used to securely hold the dam in position.** * **Retracting-anchoring clamp**: * **These are clamps especially designed to other functions besides anchoring the dam to the tooth.** **Rubber dam clamp forceps**: * **Instruments hold the clamp to facilitate its placement on the tooth.** * **Also, necessary to remove the clamp during removal of the rubber dam.** **Rubber dam napkins**: * **These are properly designed and constructed absorbent paper or cloth towels that can be used to separate between the rubber dam and the patient's face.** * **It has the following advantages**: * **Prevent saliva drooling if it leaks from the corner of the mouth.** * **Prevents friction between the dam material and skin of the patient face especially in allergic patients.** * **Act as a cushion at the corners of the mouth reducing the dam tension and pressure across the face.** * **Used to wipe the patient lips when removing the dam.** **Lubricant**: * **Lubricants applied in the area of the punched holes facilitate the passing of the dam through the tight contacts.** **Dental floss**: * **Dental floss is used to**: * **Examining the contact points before passing the rubber dam.** * **Adjusting the septal portions of the rubber.** * **Invaginating the rubber around the cervix of the tooth to hold the dam in place.** **Modeling compound**: * **It is used to secure the clamps on the teeth to help in preventing their movement during the operative procedure.** * **DR MOHAMED ELFOGHI** **Anchors other than clamps**: * **To eliminate the need for an anterior retainer and to further secure the dam on the tooth that is most remote from the posterior clamp, several anchors other than clamps could be used.** * **These are**: * **Small pieces of rubber dam material cut from a sheet of dam is first stretched, passed through the contact, and then released.** * **Wooden wedges placed between teeth.** * **Using ligatures.** **Rubber dam holder**: * **The main objectives for the use of these devices are**: * **Keep the peripheries of the dam out of the mouth.** * **Stretch the applied dam in four directions.** * **To retract the tongue, check and lips.** * **To dear the operation field for further procedures.** * **They can be classified as**: * **Strap type**: * **Depends on the back of the patient's head for anchorage.** * **Examples**: * **Woodburry holder.** * **Wizzard holder.** * **Advantage**: * **Most convenient for the operator because they do not obstruct the field of vision in any direction.** * **Hanging form holder**: * **Are U-shaped or rectangular metal or plastic frames, with multiple prongs at their peripheries that can engage the stretched rubber.** * **Those are the most popular holder.** * **DR MOHAMED ELFOGHI** **Advantages**: * **The ease of application** * **The allowance for minimal contact of the rubber with the skin.** **Disadvantage**: * **They may be in the access of the field of operation.** **The isolation of the operating field can be done by retraction and harm prevention** **Retraction and access**: * **It gives maximum exposure of the operating site.** * **It involves maintaining an open mouth and retraction of the gingival tissue, tongue, lips, and check.** * **Retraction and access are achieved with**: * **The rubber dam.** * **High-volume evacuator.** * **Absorbents.** * **Retraction cord.** * **Mouth prop.** **Harm prevention**: * **Small instruments and restorative debris can be aspirated or swallowed.** * **Harm prevention are achieved with**: * **Rubber dam.** * **Suction devices.** * **Absorbents.** * **Throat shield.** * **Mouth prop.** * **DR MOHAMED ELFOGHI** **** ### **CONTROL OF PAIN** **Definitions** * **Hypersensitivity**: → **An exaggerated sharp transient sensation or discomfort does not associated with tissue damage.** * **Pain**: → **Unpleasant sensation due to sever stimuli and always associated with a degree of tissue damage and warns that there is something wrong in need for treatment.** **Types of pain** * **Pre-operative pain**: * **Due to defects of hard or soft dental tissues.** * **It may be referred from ENT, eye or maxillary sinus.** * **It drives the patient to seek for dental treatment.** * **Operative pain**: * **Due to instrumentation or restoration procedures.** * **Post-operative pain**: * **As a result of operative pain or due to failure of the restoration.** **Causes of pain** * **Defect in hard dental tissues.** * **Defects in soft tissues.** * **Instrumentation**: * **Hand cutting instruments: ** * **Heat.** * **Rotary cutting instruments: ** * **Heat.** * **Vibration.** * **Physical and chemical irritation**: * **Dehydration of the cavity.** * **Strong drugs.** * **Miscellaneous.** * **DR MOHAMED ELFOGHI** **Defects in hard dental structures**: * **Caries**: → **Bacterial pathological irreversible disease affecting hard dental tissues.** * **Erosion**: → **Chemico-mechanical destruction of hard tooth structure without bacteria.** * **Abrasion**: → **Mechanical wearing of the hard tooth structure.** * **Attrition**: → **Physiological wearing of the hard tooth structure.** * **Fractured or cracked tooth.** * **All these defects will cause pain due to exposure of the dentin-pulp organ to the following stimuli**: * **Mechanical stimuli.** * **Thermal stimuli.** * **Chemical stimuli.** * **Galvanic stimuli.** * **Osmotic stimuli.** **Thermal stimuli**: * **Temperature fluctuation between 85 - 135°F or 26 - 47°C causes pain as it decreases viscosity of dentinal fluid.** * **According to the osmotic gradient, dentinal fluid will move leading to pain.** **Osmotic stimuli**: * **Difference in osmotic pressure will cause movement of the dentinal fluid with pain production.** **Galvanic stimuli**: * **Short cycle**: → **Through direct contact between two dissimilar metallic restorations.** * **Long cycle**: → **Saliva acts as electrolyte that transmits the galvanic shock and will cause pain.** * **DR MOHAMED ELFOGHI** **Defects in soft tissues**: * **Ulcers or abscess.** **Instrumentation**: * **Hand cutting instruments**: * **Dull hand cutting instruments require greater force applied on the tooth structure, which will give greater compression on dentin.** * **This will distribute the force over a wider area of contact resulting in pain.** * **Rotary instruments**: * **Heat**: * **Blunt burs produce more friction with the tooth structure and this resulting in more heat generation with more pain.** * **Pain from cavity preparation is mainly due to**: * **Heat generation.** * **Cutting a large number of D.Ts.** * **Vibration**: * **Vibration is an unpleasant sensation experienced by the patient, which lowers the pain threshold.** * **Patient can tolerate vibrations of 150-200 cycle/second.** * **Vibrations above 560 cps can not be tolerated.** * **Vibration is absent when using high speeds.** * **DR MOHAMED ELFOGHI** **Physical and chemical irritations**: * **Dehydration of the cavity**: * **Using air jet can produce a histological effect on the pulp such as → migration of the odontoblastic nuclei into the proximal ends of the dentinal tubules resulting in pain.** * **Air should be applied only until the film of moisture is seen disappear from the cavity.** **Strong drugs**: * **Strong antiseptics in the deep cavities is contra-indicated to avoid postoperative pain.** **Miscellaneous**: * **Cutting at DEJ.** * **Pressure exerted by rubber dam clamps, matrix band, retainers, wedges and separation of teeth.** * **Packing of gingival retraction strings prior to an impression of a