№ 22Writing an extended medical card (history of disease) of dental patient with a diagnosis of periodontitis

16. Filling in chart of dental patient that suffers different forms of pulpitis.

General dental practitioners routinely manage the sequelae of pulpal and periapical inflammation. Differential diagnosis of facial pain can however be very challenging. The patient with endodontic disease will notnecessarily present with toothache, and a pain that may at first appear to be of endodontic origin could be referred from elsewhere or even be psychogenic. A careful and methodical approach to history taking,examination and applying special tests will save time and expense at a later date. Cutting corners can unfortunately lead to embarrassing mistakes, and possibly litigation.Using a surgical sieve to aid history taking and examination is not an original method,but is an invaluable approach for diagnosis in dentistry.

Classification

I. Acute pulpitis

1. Hyperemia of pulp.

2. Acute limited (partial) pulpitis.

3. Acute diffuse pulpitis.

4. Acute purulent pulpitis.

5. Acute traumatic exposure of pulp

II. Chronic pulpitis.

1. Chronic fibrous pulpitis.

2. Chronic hypertrophic pulpitis (pulp polyp).

3. Chronic gangrenous pulpitis

4. Chronic concrementous pulpitis.(pulp stone)

III. Exacerbation of chronic pulpitis.

IV. Pulpitis, complicated with periodontitis.

Reasons

Pulpitis is the most common cause of dental pain and loss of teeth in younger persons. The usual cause is caries penetrating the dentine but there are other possibilities . Pulpitis, if untreated, is followed by death of the pulp and spread of infection through the apical foramina into the periapical tissues. This in turn causes periapical periodontitis. Dental caries is by far the most common cause and is usually obvious unless it has extended under the edge of a restoration. Exposure during cavity preparation allows bacteria to enter the pulp and also damages it mechanically. Fracture may either open the pulp chamber or leave so thin a covering of dentine that bacteria can enter. A tooth, particularly a restored premolar, may split, usually under masticatory stress . These minute cracks are often invisible, but allow bacteria into the pulp chamber. The affected tooth may sometimes be identified by applying pressure to the occlusal fissure with a ball-ended burnisher to open up the crack. Pulp pain usually then results. Alternatively the crack may be made visible with oblique transillumination or, possibly more easily, by wetting the crown of the tooth with a dye such as fluorescein and visualising it with ultraviolet light.

Over-rapid cavity cutting, especially of deep cavities, can cause immediate damage to the pulp. Large unlined metal restorations may also allow continuous low-grade thermal stimuli to damage the pulp over a longer period. Some restorations without a protective lining, particularly, in the past were sufficiently irritant to kill the pulp.

Clinical features

Acute pulpitis

In the early stages the tooth is hypersensitive. Very cold or hot food causes a stab of pain which stops as soon as the irritant is removed. As inflammation progresses, pain becomes more persistent and there may be prolonged attacks of toothache. The pain may start spontaneously, often when the patient is trying to get to sleep.

The pain is partly due to the pressure on the irritated nerve endings by inflammatory infiltrate within the rigid pulp chamber and partly due to release of pain-producing substances from the damaged tissue. The pain at its worst is excruciatingly severe, sharp and stabbing in character. It is little affected by simple analgesics.

Chronic pulpitis

The pulps of individual teeth are not precisely represented on the sensory cortex. The pulp pain is therefore poorly localized and may be felt in any of the teeth of the upper or lower jaw of the affected side. Rarely, pain may be referred to a more distant site such as the ear. Pulp pain is not provoked by pressure on the tooth. The patient can chew in comfort unless there is a large open cavity allowing fragments of food to press on the pulp through the softened dentine. Many pulps under large carious cavities die painlessly. The first indication is then development of periapical periodontitis, either with pain or seen by chance in a radiograph. In other cases there are bouts of dull pain, brought on by hot or cold stimuli or coming on spontaneously. There are often prolonged remissions.

Key features of pulpitis • Pulpitis is caused by infection or irritation of the pulp, usually by caries

• Severe stabbing pain in a tooth, triggered by hot or cold food or starting spontaneously, indicates acute irreversible pulpitis

• Pulp pain is poorly localised

• Chronic pulpitis is often symptomless

• Untreated pulpitis usually leads to death of the pulp and spread of infection to the periapical tissues Pulpal pain

The pulp may be subject to a wide variety of insults, e.g. bacterial, thermal, chemical, traumatic, the effects of which are cumulative and can ultimately lead to inflammation in the pulp (pulpitis) and pain. The dental pulp does not contain any proprioceptive nerve endings, therefore a characteristic of pulpal pain is that the patient is unable to localize the affected tooth. The ability of the pulp to recover from injury depends upon its blood supply, not the nerve supply, which must be borne in mind when vitality (sensibility) testing is carried out (p. 18).1 It is impossible to reliably achieve an accurate diagnosis of the state of the pulp on clinical grounds alone; the only 100% accurate method is histological section.

Although numerous classifications of pulpal disease exist, only a limited number of clinical diagnostic situations require identification before effective treatment can be given.

Reversible pulpitis

Symptoms. Fleeting sensitivity/pain to hot, cold or sweet with immediate onset. Pain is usually sharp and may be difficult to locate. Quickly subsides after removal of the stimulus.

Signs. Exaggerated response to pulp testing. Carious cavity/leaking restoration.

Rx Remove any caries present and place a sedative dressing (e.g. ZOE) or permanent restoration with suitable pulp protection.

Irreversible pulpitis

Symptoms .Spontaneous pain which may last several hours, be worse at night, and is often pulsatile in nature. Pain is elicited by hot and cold at first, but in later stages heat is more significant and cold may actually ease symptoms. A characteristic feature is that the pain remains after the removal of the stimulus. Localization of pain may be difficult initially, but as the inflammation spreads to the periapical tissues the tooth will become more sensitive to pressure.

Signs. Application of heat (e.g. warm GP) elicits pain. Affected tooth may give no or a reduced response to electric pulp tester. In later stages may become TTP.

Rx Extirpation of the pulp and RCT is the treatment of choice (assuming the tooth is to be saved). If time is short or if anaesthesia proves elusive then removal of the coronal pulp and a Ledermix dressing can often control the symptoms until the remaining pulp can be extirpated under LA at the next appointment.

The histopathology of pulpitis

Acute pulpitis

Early changes within the pulp from the advancing carious lesion involve the production of tertiary dentine by the odontoblasts. Tertiary dentine, formerly known as irregular secondary dentine, contains fewer tubules than primary or secondary dentine. Tertiary dentine may be reactionary, laid down by primary odontoblasts in response to a mild stimulus, or reparative dentine, laid down by secondary odontoblasts derived from other pulp cells. This attempt at a barrier to the advancing lesion can be effective if the lesion progresses slowly and particularly so if it arrests. However, with the advancing lesion, bacteria invade the odontoblasts and destroy the surrounding tissues. Clinically it is characterised by the patient feeling pain in response to temperature change which lasts for the duration of the stimulus. There is normally no pain on biting or when the tooth is percussed. The inﬂammation of the pulp is reversible if the cause is successfully treated, e.g. by the removal of the caries. As the pulpal inﬂammation becomes more extensive, the pain experienced as a result of temperature change becomes more severe and persists after the removal of the stimulus usually for several minutes or even longer. As the lesion approaches the pulp, inﬂammatory responses are detected in front of the advancing lesion.

Once penetration of the pulp by bacteria has taken place, the inﬂammatory process becomes more profound. The response of the tissues to this invasion is seen clinically as acute pulpitis. The inﬂammation produces an increase in pressure on the walls surrounding the pulp because of the presence of additional inﬂammatory cells, increased vascularity (hyperaemia) and the inability of the pulp chamber to expand to relieve the pressure causing the typical symptoms of acute pulpitis. These are:

■ A constant, throbbing pain in the affected tooth that is

often made worse by reclining or lying down.

■ A lack of pain on biting unless the inﬂammation has

spread beyond the conﬁnes of the pulp.

■ The inability to obtain relief from the pain.

Other processes which can lead to bacteria penetrating the pulp are trauma, e.g. a fractured tooth or traumatic exposure during cavity preparation (iatrogenic), tooth wear, via the periodontal membrane or, rarely, via a bacteraemia, e.g. induced by a tooth extraction from another site (anachoresis).

SURGICAL SIEVE

A typical surgical sieve will include the following headings:

• Biographical details

• Medical history

• Chief complaint

• History of present complaint

• Dental history

• Social history

• Extraoral examination

• Intraoral examination

• Special tests

• Radiographs

• Diagnosis

• Treatment plan

MEDICAL HISTORY

There are virtually no medical contraindications to routine endodontic treatment. Debilitating disease, recent myocardial infarctionand uncontrolled diabetes will delaytreatment. The dental practitioner may require further advice from the patient's medical practitioner on the pharmacology associated with complex drug regimes before embarking on treatment. Fortunately, most patients that present in the dental surgery with systemic disease are well controlled and pose no problem to routine treatment.

A thorough and complete medical history should be taken when the patient has an initial consultation; this is then updated regularly at subsequent appointments. Working from a proforma is one of the most efficient and easiest methods. Vital questions are not overlooked,and it is easy to update at following appointments.

Points of interest can be highlighted for all staff treating the patient, and may be particularly useful in an emergency situation.

More frequently patients present with allergies- those to antibiotics and latex are becoming more common. Obviously prescribing patterns should be consistent with any allergy, and it is now possible to use nonlatex gloves and rubber dam. The emergency treatment of anaphylaxis is discussed later.

A MEDICAL HISTORY PROFORMA

CONFIDENTIAL - MEDICAL HISTORY

To be completed by patient (delete as appropriate)

FULL NAME .............................................................................................................

DATE OF BIRTH . . . . . . / ....../...... OCCUPATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

WHO IS YOUR REGISTERED MEDICAL PRACTITIONER? ...........................................................

ADDRESS OF MEDICAL PRACTITIONER ......................................................................................

1. Have you ever had Rheumatic Fever? Yes No

2. Do you have Heart Trouble or High Blood Pressure? Yes No

3. Do you have Chest Trouble? Yes No

4. Have you had Jaundice or Hepatitis, or been refused as a blood donor? Yes No

5. Have you ever had severe bleeding that needed special treatment after aninjury or dental extraction? Yes No

6. Is there any family history of Bleeding Disorders? Yes No

7. Are you taking any Drugs, Tablets, or Medicines? Yes No

I f 'Yes' please list .....................................................................................................................

8. Do you suffer from any Allergies (e.g. Penicillin)? Yes No

I f 'Yes' please list ....................................................................................................................

9. Are you Diabetic? Yes No

10. Do you have any history of Epilepsy? Yes No

11. Have you had any a) Serious Illnesses or Operations? Yes No

or b) Adverse reactions to Local or General Anaesthesia? Yes No

12. Have you come into contact with anybody who has AIDS or is HIV positive? Yes No

13. (Females only) Are you pregnant? Yes No

Please add anything else you feel might be of importance:

DATE CHECKED

INFECTIVE ENDOCARDITIS

There is general consensus on the recommendations for the prevention of infective endocarditis following dentistry.A working party of the British Society for Antimicrobial Chemotherapy advocated that the only dental procedures likely to produce asignificant bacteraemia were extractions, scalingor surgery involving the gingivae.Significant bacteraemia was unlikely to be produced from root canal instrumentation.There are studies in the endodontic literature that support this. Only gross over preparation beyond the apex of the tooth an into periapical tissues has produced a bacteraemia.Clinical conditions and presentation vary, and if in doubt a practitioner should contact the patient's general medical practitioner or physician for advice and a secondopinion. It may for instance be prudent to provide antibiotic prophylaxis where a tooth is acutely infected or there is significant associated periodontal disease.

ANTIBIOTIC PROPHYLAXIS

Procedures under Local Anaesthetic

Patients who are not allergic to penicillin and

have not been prescribed a penicillin more than

once in the preceding 4 weeks:

Amoxycillin

Adults: 3 g single oral dose 1 hour prior toprocedure (this should be supervised, as thereis a risk of anaphylaxis)

Children 5-10 years: half adult dose

Children under 5 years: quarter adult dose

A second dose is recommended 6-8 hourslater to ensure adequate cover in high-riskpatients.

Patients allergic to penicillin or who have hadpenicillin prescribed within the preceding 4 weeks:

Clindamycin

Adults: 600 mg single oral dose 1 hour priorto treatment (this should be supervised)

Children 5-10 years: half the adult dose

Children under 5 years: quarter the adult dose

PATIENTS AT RISK OF INFECTIVE ENDOCARDITIS

A known history of rheumatic fever

Congenital heart disease

Murmurs associated with cardiac disease

Valve replacements

Patients who have previously suffered an attack of infective endocarditis (this ismore common in diabetics, IV drugabusers and patients on haemodialysis)

Patients deemed to be at risk by their physician

Patients who have undergone by pass grafting or heart transplant are not considered to be atrisk of endocarditis; but it would be wise to seek a medical opinion if in doubt.

The risk of bacteraemia can be reduced quite simply by using a 0.2% chlorhexidine mouthwash preoperatively. The solution should be swilled around the mouth for at least one minute before endodontic treatmentor used three times daily, starting 24 hours prior to treatment. Chlorhexidine mouthwash significantly reduces the bacterial load in theoral cavity. The patient will be best served by well-planned and well-executed treatment, as opposed to ineffective root canal treatment. Antibiotic cover is obviously required for at risk patients undergoing surgical endodontics procedures and replantation of teeth.

CHIEF COMPLAINT

This is the opportunity for the general practitioner to let the patient describe a dental problemas it appears to him/her. You may start with 'Tell me about your problem' or 'Howcan I help? Allowing time to listen to thepatient in a busy schedule can pay dividendsin reaching the correct diagnosis swiftly andavoiding embarrassing mistakes. A distressed patient will be put at ease, and conversation can then lead into more detailed discussion.

HISTORY OF PRESENT COMPLAINT

The discussion is now carefully guided to glean further more detailed and important facts without pre-empting an answer. Leading questions should be avoided.

When did the pain or problem start?

Does anything make the pain better of worse?

Application of heat, cloves or pressure may have eased the pain. Have any analgesics been taken? Large doses ofanti-inflammatory drugs can depress any discomfortand could alter the practitioner's prescription of further analgesics.

Relieving factors. Lying down, hot water bottles,whisky, and sucking on an aspirin tablet are often used by patients in an attempt torelieve pain!

The frequency of painful episodes. Do pain come and go, or is there a continuous ache? Pain when chewing could be due to apical periodontitis, a cracked cusp or an overbuilt filling.

Intensity. Has the patient been kept awake at night?

Location. An irreversibly pulpitic tooth may not be easily identified by the patient, as the pain can be referred or radiate. Referral of pain occurs along the jaw of the same side, from maxilla to mandible and vice versa,but never across the midline. A tooth with acute apical periodontitis is often tender to bite on and can therefore be identified easily.

Duration. Spontaneous aching and throbbing is often indicative of an irreversible pulpitis or acute apical periodontitis. A tooth is classified as chronic if it is symptomless; this doesnot however refer to the cell types histologically.

Postural changes. Does the pain increase when lying down or bending over?

Does anything trigger the pain? Pain of short duration following stimulation with hot of cold can often be due to a reversible pulpitis, as with a leaking or recent restoration. Pain lasting several minutes, especially after a hot stimulus, may suggest an irreversible pulpitis.

Quality of pain. Is it sharp, stabbing, radiating,throbbing or dull?

DENTAL HISTORY

Is the patient a regular attender? Will he/shebe motivated enough to have the endodontically treated tooth restored, or would extraction be a better course of treatment?

Has he/she presented in pain? If so, howbad is it? Has it kept him/her awake? Ask thepatient to grade it on a scale of 1 to 10.

Is the patient particularly nervous of dentistry?Is there a history of difficult extractionsor a particularly problematic root canal treatment? Referral to a specialist colleague maybe necessary.

Has the patient recently had any restorationsplaced? Overbuilt or deep fillings may be associated with transient pain after placement.

SOCIAL HISTORY

A social history may be helpful when symptoms and signs do not seem to fit the history of dental pain. The highly distressed, depressed or stressed individual may present with anatypical or psychologically derived pain.

EXTRAORAL EXAMINATION

Palpation

Lymph nodes can be gently palpated with the fingertips. Lymphadenopathy of the submandibular lymph nodes could be an indication of infection in the oral cavity. Tenderness may indicate a site of acute inflammationdeep to the skin (Fig. 1.1).

Facial Swelling

Are there any signs of acute inflammation -heat, swelling, redness, pain, loss of function- and does the patient have a raised body temperature?

Does the patient feel that his/her face is swollen in any way? Ask patients to look in amirror and point to any perceived swelling.The practitioner can assess the facial contourin profile and by looking down the bridge ofthe nose from above to see any asymmetry in the nasolabial folds (Figs. 1.2, 1.3). Facial asymmetry can be due to guarding of painful tissues.

Figure 1.1

Palpation of the submandibular lymph nodes. The clinicianis positioned behind the patient and palpates the nodes gently with finger tips.

Figure 1.2

A patient with facial swelling (arrowed).

Figure 1.3

Asymmetry in the right nasolabial folds is more visiblewhen viewed from above.

External Sinus Tracts

Rarely, a sinus tract leading from an abscess at the apex of a tooth can point externally; this issometimes seen in the mandibular or maxillary incisor regions (Figs. 1.4, 1.5). The tracts point as a spot on the chin or just inside then are respectively. The spot does not heal, and may discharge pus.

INTRAORAL EXAMINATION

Ease of access: Is it possible for the patient to open his/her mouth sufficiently wide for root canal treatment? If two fingers can be placed between the maxillary and mandibular incisor tips then it should be possible to instrument most teeth (Fig. 1.6).

General condition of the mouth: Is the mouth in good health or neglected? Are there heavy plaque deposits and evidence of gross periodontal disease (Fig. 1.7)? Are restorations of good quality, or are the margins overhanging and poorly finished? Is there obvious recurrent caries present (Figs. 1.8, 1.9)?

Figure 1.4

An external sinus tract on the chin that drained from themandibular incisors.

Figure 1.5

A paralleling radiograph of the mandibular incisorsshowed a periapical radiolucency. The central incisors were non-vital, and pus was draining through the external sinus tract.

Figure 1.6

Sufficient opening is required to gain access to the teethfor endodontic treatment. Two fingers' width in the incisor region is perfectly adequate.

Figure 1.7

A neglected mouth. The patient will need advice on oralhygiene prior to endodontic treatment.

Tooth mobility: A suspect tooth can bemoved gently by finger and thumb pressure;any horizontal mobility is then graded (Fig.1.10).

Grade I 1 mm Slight

Grade II 1-2 mm Moderate

Grade III > 2 mm and vertical Extensive

Mobility can result from trauma, root fractures,periodontal disease and gross root resorption. Sometimes a very slight (< 1 mm)degree of mobility may be normal. For instance, a tooth that has a horizontal root fracture in the middle third could be expected to have a degree of mobility, as would teeth under active orthodontic traction. Neither would necessarily require treatment purely because of the mobility.

Figure 1.8

The overhanging restoration on the buccal surface of thismandibular molar has provided a site for plaque accumulation,and active caries is now present under the restoration.

Figure 1.9

A radiograph showing advanced recurrent/root caries(arrowed). This tooth is probably unrestorable.

Figure 1.10

Testing tooth mobility by gently applying lateral forcesbetween finger and thumb.

Figure 1.11

Gently percussing a tooth with a mirror handle may elicitthe classical ringing sound that occurs with replacementresorption (ankylosis).

Tenderness to palpation: The tooth is movedvertically and side to side with finger pressure.Teeth with acute apical periodontitis will often be tender when palpated in this manner.

Percussion: Tapping a tooth with a mirror handle can help identify replacement resorption(ankylosis). A characteristic ringing sound is sometimes heard on percussion (Fig.1.11).

Palpation of the buccal sulcus: Running a finger gently along the buccal sulcus will helpelicit if there is any swelling or tenderness over the apex of an offending tooth(Figs.1.12, 1.13).

Intraoral sinus tracts: These are usually seen on the attached buccal gingiva. The gingivashould be gently dried with a three-in-onesyringe, and examined closely under good illumination (Figs. 1.14, 1.15). Running a finger along the mucosa may elicit a discharge from the sinus tract (Fig. 1.16). The tract exit may not always be adjacent to the offending tooth (Fig. 1.17). Sinus tracts exit less commonly on the palate (Fig. 1.18). When taking a radiograph for diagnosis it is useful to place a gutta percha point in the tract to identify thesource of the problem (Figs. 1.19, 1.20).

Periodontal pocketing: Probing depths should be measured carefully with a periodontal probe. Ideally a probe with a tip of 0.5 mm should be used and pressure of no more than25 g applied (light pressure!). Broad pockets are normally due to periodontal disease. A sudden increase in probing depth resulting in a narrow but deep pocket may indicate the position of a vertical root fracture or sinus tract lying within the periodontal ligament(Figs. 1.21-1.25).

Mobility of fixed prosthodontics: Inserting a probe under the pontic of a bridge and applying a pulling force can be used to test whether either abutment is loose (Fig. 1.26). The margins of full crown restorations can be tested with a probe (Figs. 1.27, 1.28).

Figure 1.12

Palpating the buccal sulcus over the apices of the teeth,with a finger tip. Any tenderness or swelling is noted.Tenderness may be an indication of acute apical periodontitis.

Figure 1.13

A buccal swelling in the anterior region. Some swellingsmay not be visible but can be palpated.

Figure 1.14

An intraoral sinus tract in the anterior region.

Figure 1.15

An intraoral sinus tract in the posterior region.

Figure 1.16

Pus discharging from the anterior sinus tract.

Figure 1.17

In this patient a sinus tract opposite the lower molar(indicated by ring) tracked along the mandible to theperiapical abscess on the premolar. Sinus tracts do not always point adjacent to the offending tooth. Vitality testing and good radiological techniques are needed to identifythe source of the problem.

Figure 1.18

A palatal sinus tract in the anterior region.

Figure 1.19

Placing a gutta percha point in a sinus tract to identify the source of the problem. This will not be painful, as the sinus tract is often epithelialized. Topical anaesthetic get may occasionally be required.

Figure 1.20

A radiograph of a gutta percha point inserted into a sinus tract adjacent to a mandibular molar.

Figure 1.21

An extracted tooth with a vertical root fracture. In this case the tooth had fractured despite having been crowned.

Figure 1.22

An occlusal view of a maxillary premolar that had fractured vertically in a mesial-occlusal-distal plane.

Figure 1.23

The maximum periodontal probing depth on the mesial aspect was 7mm. The pocket shape was deep and narrow.

Figure 1.24

There were 1.0-1.5 mm probing depths buccally.

Figure 1.25

The probing depth of 7mm on the distal aspect of the tooth directly opposite to that on the mesial aspect was indicative of a vertical root fracture.

Figure 1.26

Inserting a probe under the pontic of a bridge to test for mobility.

Figure 1.27

Testing for marginal deficiencies around a crown using a Briault probe.

Figure 1.28

A DG16 probe (Hu Friedy, Chicago, IL, USA) can be used to test the margins of restorations.

SPECIAL TESTS

Pulp Testing

Pulp testing is used to assess whether a pulp is vital. Most methods test whether the nerve fibres within the pulp are able to conduct impulses. Laser Doppler flowmetry is still an experimental method of assessing the blood flow in the pulp.

The teeth adjacent to that with question able pulp vitality and a contralateral tooth are often assessed to give a comparison.Sometimes more than one tooth may be the cause of a patient's symptoms. Teeth may be naturally sensitive or consistently record low responses to electric and thermal stimuli.

Thermal Tests

Cold. Cold can be applied to teeth in the form of an ice stick made using a needle cover,carbon dioxide snow, ethyl chloride on a pledget of cotton wool, cold water and rubberdam (Fig. 1.29). Blowing an air stream in discriminately across the teeth from a three-in -one syringe is not a useful test of vitality, as it is impossible to isolate the air-stream to one tooth.

Heat. An electric heater-tip, rubber wheel, orhot gutta percha (Fig. 1.30) can be used. When using hot gutta percha it is wise to have local anaesthetic to hand and to cover the tooth surface with petroleum jelly to prevent the sticky rubber from adhering to the tooth(Figs. 1.31, 1.32). Isolating teeth individually with rubber dam and applying hot tap water in a syringe is an excellent method of testing individual teeth when diagnosis is difficult or if a patient describes the pain as being stimulated by a hot drink.

Electric Pulp Testing

Electric pulp testers use an electric current(AC or DC) to stimulate a response from the nerve tissue in the pulp. An example is the Analytic Technology pulp tester (Fig. 1.33).The unit switches on automatically when a circuit is made. The current at the tip is then increased by a microprocessor until the circuitis broken or maximum current is reached. A digital readout from 0 to 80 is given on anLED display. It is possible to increase of decrease the rate of electrical stimulus.

Method of use. The tooth to be tested is dried, to avoid short-circuiting through saliva into the periodontium. A tooth may also need to be isolated with strips of rubber-dam between the contact points to prevent conduction through metallic restorations into adjacent teeth (Fig. 1.34). A small amount of conducting medium such as KY jelly or tooth- paste is then applied to the tip of the pulptester (Fig. 1.35). Mono-polar testers such asthe Analytic Technology tester require the circuit to be completed by the operator of patient. Since the operator is wearing rubber gloves, the circuit will not be complete. Thepatient is asked to hold the metal handle ofthe instrument until a tingling sensation is felt in the tooth (Fig. 1.36); at this point the patient should let go and the stimulus will cease. A reading can be taken from the LED display.

Figure 1.29 The tooth is isolated with rubber dam and immersed in cold water.

Figure 1.30 blot gutta percha can be used to test a tooth for heat sensitivity.

Figure 1.31

Vaseline is placed on the tooth surface to prevent the rubber sticking.

Figure 1.32

The heated gutta percha is placed on to the tooth.

It should be remembered that electric pulptesting does not give an indication of vascular health, which is especially important in traumatized immature teeth. It is possible to get a false positive reading via periodontal short circuiting, and in multi-rooted teeth there may be varying degrees of vitality in separate roots.

Figure 1.33

An electric pulp tester.

Figure 1.34

Adjacent teeth are sometimes isolated with rubber dam to prevent short-circuiting through metal restorations.

Measurement of Blood Flow

Laser Doppler flowmetry. These units are notcurrently marketed for use in dental surgeries,but it may be possible to refer patientsfor Laser Doppler assessment at a teaching hospital. This method will give an indication of the vascular health of a pulp, and is particularlyuseful when assessing immature teeth that have been traumatized (Figs. 1.37, 1.38).

Figure 1.35

The tip of the electric pulp tester is coated in toothpaste to improve conductivity.

Figure 1.36

A circuit is made when the patient holds the metal handle.

Other Methods

Local anaesthetic. Applying local anaesthetic asan intraligamental injection may help elicit the offending tooth. Teeth adjacent to theinjection site may also be affected by the anaesthetic. This method could be used to identify whether a maxillary or mandibular tooth is the cause of referred pain.

Figure 1.37

A Laser Doppler machine.

Figure 1.38

The Laser Doppler probe.

Figure 1.39

A fibre optic light for assessment of cracks.

Figure 1.40

A tooth is illuminated to visualize a crack (arrowed)

Cutting a Test Cavity

As a last resort a cavity can be cut in the tooth with no local anaesthetic. This is not totally reliable, however, as sometimes partially necrotic pulps in teeth that require root canal treatment will respond to drilling. Cold coolant spray can also stimulate adjacent teeth.

Identifying Cracked Cusps

Teeth with cracked cusps are sometimes sensitive to thermal stimulation. Identifying the fractured cusp can be difficult, as the fractureline may not be visible to the naked eye.

Transillumination with a fibre optic light may highlight a crack (Figs. 1.39, 1.40).

A plastic 'Tooth Slooth' or wooden bite stick can be used to apply pressure to individual cusps on a tooth (Figs. 1.41, 1.42).

Asking a patient to bite on the corner of a folded sheet of rubber dam may elicit pair from a cracked cusp (Fig. 1.43).

RADIOGRAPHY

Accurate and predictable radiographic techniques are essential for endodontics diagnosis and treatment.

The X-ray Unit

The X-ray machine should comply with currentionizing radiation regulations. A tube voltage of 70 kV is ideally suited for intraoralradiography. The beam produced by theX-ray head is divergent, and must be filtered and collimated to produce a parallel source.Filtration is equivalent to 1.5 mm of aluminium for units up to 70 kV. Collimation produces a beam that is no larger than 60 mm.

Figure 1.41

A Tooth Slooth being used to apply pressure to an individual cusp.

Figure 1.42

This tooth was completely fractured.

Figure 1.43

Biting on a rubber dam sheet may cause a cracked cuspto flex, aiding diagnosis.

A spacer cone allows correct alignment an correct distance from focal point to skin. This distance should be 200 mm for units operating at 70 kV. All X-ray units should have a warning light and sound to indicate whenX-rays are being emitted.

Dose Reduction

It is important to keep all exposure to ionizing radiation as low as is reasonably achievable(ALARA). Whenever exposing the patient to X-radiation the clinician must assess the probability of obtaining useful information and ensure that it is maximized.

Physical methods of limiting and reducingthe dose of radiation include:

• Only taking a radiograph when clinically essential

• Complying with Health and Safety regulations(including beam size and filtration)

• Using an X-ray unit with at least 70 kV output

• Using a film with the shortest exposure time feasible for the clinical condition.

All radiographic techniques should be made as accurate as possible. Avoiding the need to repeat films obviously reduces X-ray dose and maximizes the diagnostic value of eachimage.

Techniques Available

Radiographic films are probably the most widely used method in general dental practice. However, with increasing computerization digital radiography offers a new an exciting alternative.

Radiographic Film

The D-Speed radiographic film was used for many years, but has now been superseded by E-speed film, which gives excellent clarity of image with fine detail. Wet processing using fast-acting chemicals can produce a readable image for viewing in approximately 2 minutes.

Film speed. Film speed is a function of the number and size of the halide crystals in the emulsion. The larger the crystals the faster the film; but the quality of the image may suffer.In clinical situations the fastest film possible that will achieve the desired result should be used. For endodontic treatment there is no significant difference in the clarity of image when using D- or E-speed film. Most university dental schools now use E-speed film routinely.

Practical Points in General Radiographic

Film Technique

Film Storage

Radiographic film should be stored in cooldry conditions (in a refrigerator) away from chemicals, especially mercury-containing compounds. The film packets should be stored well away from sources of ionizing radiation and boxed until required; this avoids films becoming damaged or bent. Films must not be bent, as otherwise an artefact will appear on the film.

Processing

Radiographic film can be developed manually or automatically. Processing involves to stages, development and fixing. To obtain good radiographic images careful quality control must be implemented and the physical conditions under which the films are processed must be tightly controlled and standardized.

Development

Development of the X-ray film should be carriedout in complete darkness or filtered light,either in a darkroom or glove-box (Fig. 1.44).The entrance handles on such boxes should be replaced if they become worn or damaged, as this may allow light to penetrate the box. It is very important to mix developer solution to the correct concentration according to the manufacturer's recommendations. Solutions must be replaced regularly and the containers washed thoroughly in clean water.

Figure 1.44

A hand-developing tank for radiographs.

Used developer solution should not be discarded in a surgery sink. Ready-mixed solutions are obviously easier to use, as they require no dilution. The temperature of developing solution should be maintained at an optimum level (usually 20°C). To avoid fluctuations in temperature a glove-box should be positioned in the surgery away from direct sunlight, heaters or autoclaves. Increasing the temperatureor extending development time will lead to dark unreadable films; if the solution is too cold or development time too short then a pale film will result.

Fixing Radiographic Techniques

Fixing should be carried out in a dark environment or under filtered light. The concentration of the fixer solution is important for consistent results. Ideally the film should be fixed for twice the development time. It ispossible however to view a film prematurely(working length estimation) before returning it to the fixing solution. Inadequate filing results in a green/yellow discoloration that eventually turns brown.

Automatic Processors

Automatic development ensures that controlled standardized conditions for time and temperature of processing are maintained.The concentration of developer and fixer solutions is important for quality control and predictable results. The rollers and containers of automatic developers should be washed regularly to prevent build-up of chemicals.

Digital Radiography

Digital radiography is a relatively new development for dental use. It offers an exciting alternative to radiographic film.

Digital radiography consists of a sensor that creates an electrical signal that can be read by a computer and converted into a greyscale image. Most of the software necessary to produce digital radiographic images can be installed on computers routinely used in the dental surgery. Images can be enhanced in terms of contrast, filtering, brightness, subtraction and the addition of colours (Fig. 1.45).

Digital radiography can be direct or indirect.

Direct systems have a sensor that is attached directly to the computer by a cable. This gives almost instantaneous images. Indirect systems use a laser reading device to scan the exposed sensor before generating an image.The X-ray dose with digital systems is significantly reduced compared with E-speed film. Sensors tend to be expensive,fragile andrelatively thick (5 mm). They have a life expectancy of approximately 400000 doses(Fig 1.47).

Figure 1.47

The sensor is placed in a polythene cover to prevent contamination and cross-infection. It can be held in position with the patient's finger, or in a special Rinn holder.

There is minimal for eshortening or elongationof the periapical tissues.

Coning off is reduced.

If the same technique is used routinely then radiographs become almost reproducible.This is helpful for endodontic review.

Figure 1.54

A lateral radiolucency may be an indication of a lateral canal.

Figure 1.55

A lateral canal has been filled during obturation; it lies adjacent to a lateral radiolucency.

Figure 1.56

Rotating the cone produced a radiograph, showing an unfilled second canal.

The bisecting angle technique should really be reserved for cases in which it is impossibleto fit a holder into the patient's mouth. It is also of value in locating a horizontal root fracture, especially if the fracture line lies in the plane of the X-ray beam (Fig. 1.58).

Retching. Using a topical local anaestheticgel or spray can reduce retching. Distracting the patient by getting him/her to concentrate on gentle breathing can also help (Fig. 1.59).

Shallow palate. Placing a cotton wool roll on the occlusal surface of the teeth will help align the holder.

Edentulous spaces. So that the holder does not become tilted when the patient bites together a cotton wool roll may be used to support the bite plate (Figs. 1.60, 1.61).

Small mouth. It may not be physically possibleto fit the holder plus standard film into apatient's mouth; in this case a small film can be used or a film can be held by artery forceps.

Figure 1.57

The completed obturation revealed an even more complicated root canal system.

Figure 1.58

A bisecting angle film showed the horizontal root fracture (arrowed).

Figure 1.59

Application of topical anaesthetic gel to prevent retching.

Figure 1.60

With an edentulous ridge the Rinn holder needs to besupported, as in this case, where a periapical radiographis required of the mandibular premolar.

Figure 1.61

A cotton wool roll has been placed on the edentulous ridge to prevent the holder rotating.

DIAGNOSIS

The clinician must listen to the patient's symptoms and summate the findings of several tests to come to a decision as to the likely cause of the patient's pain and whether the health of the pulp of the suspect tooth is affected. If two or more tests indicate that a tooth is non-vital and there is evidence of radiological change then the practitioner can be relatively confident of the diagnosis. If one is unsure or the findings are not conclusive a period of observation or referral would be appropriate (Figs. 1.62, 1.63).

Pulpal condition can clinically be classified under simple headings:

Normal pulp. The normal pulp gives atransient response to thermal tests and can be stimulated by electric pulp testing; it may alsobe sensitive to sweet and to acidic foods. The electric pulp tester may produce feelings varying from a tingling sensation to pain. Palpation and percussion do not cause pain.Radiologically there is a normal periodontal ligament space bounded by an intact lamina dura. The periodontal ligament space can appear increased in width over the apex of the palatal roots of upper molar teeth, owing to the magnifying effect of the air sinus.

Figure 1.62

A diagnosis can be made after listening to the patient's symptoms and carrying out special tests. In this case the maxillary second molar appears to have an apical radiolucency.Special tests however reveal that the maxillary first molar is non-vital.

Figure 1.63 The completed root canal treatment shows that the roots of the maxillary molars are super imposed on the radiograph.A thorough and logical approach to diagnosis prevented incorrect treatment.

Reversible pulpitis. Pain induced by thermal stimuli tends to be of short duration (second rather than minutes), and does not radiate. Palpation and percussion do not stimulate pain. A filling may have been recently placed, or there may possibly be cracked cusps.

Irreversible pulpitis. Pain can be variable,from a spontaneous deep ache to total absence. Initially pain can be referred, and isusually stimulated by thermal tests, when it lasts several minutes or hours. When pulpal inflammation reaches the apex, the tooth may become tender to bite on or respond to palpation. At this point there may be radiological changes apically.

Pulpal necrosis. If the entire pulp is necrotic then the tooth will fail to respond to thermal tests; however, in multi-rooted teeththe pulp in one root may remain vital, making diagnosis by thermal tests difficult.

Radiologically, there are usually periapical changes (Fig. 1.64).