Clinical Diagnostic Procedures in Endodontics

In 2008, the American Association of Endodontists held a consensus conference to standardize diagnostic terms used in Endodontics [1-4]. The goals were to propose universal recommendations regarding endodontic diagnoses; develop a standardized definition of key diagnostic terms that will be generally accepted by Endodontists, educators, third parties and students; determine radiographic criteria, objective test results and clinical criteria needed to validate the diagnostic terms established at the conference. Both the AAE & American Board of Endodontics have accepted these terms and recommend their usage across all dental disciplines and healthcare professions [5-7].


Definition
Endodontics is a branch of dentistry that deals with the etiology, diagnosis, prevention and treatment of the diseases of the pulp and periapical tissues compatible with good health. a. To arrive at a diagnosis, there is a definitive procedure to be followed which involves step by step implementation of the clinical diagnostic methods.
b. A key purpose of establishing a proper pulpal and periapical diagnosis is to determine what clinical treatment is needed.
c. Another important purpose of establishing universal classification system is to allow communication between educators, clinicians, students and researchers.
In 2008, the American Association of Endodontists held a consensus conference to standardize diagnostic terms used in Endodontics [1][2][3][4]. The goals were to propose universal recommendations regarding endodontic diagnoses; develop a standardized definition of key diagnostic terms that will be generally accepted by Endodontists, educators, third parties and students; determine radiographic criteria, objective test results and clinical criteria needed to validate the diagnostic terms established at the conference. Both the AAE & American Board of Endodontics have accepted these terms and recommend their usage across all dental disciplines and healthcare professions [5][6][7].

Examinations & Diagonstic Procedures
a) Diagnosis cannot be made from a single isolated piece of information [4].
b) The clinician must systematically gather all of the necessary information to make a "probable" diagnosis.
c) When taking the medical and dental history, the clinician should already be formulating in his or her mind a preliminary but logical diagnosis, especially if there is a chief complaint d) The clinical and radiographic examinations in combination with a thorough periodontal evaluation and clinical testing (pulp and periapical tests) are then used to confirm the preliminary diagnosis.
e) In some cases, the clinical and radiographic examinations are inconclusive or give conflicting results and as a result, definitive pulp and periapical diagnoses cannot be made.
f) It is also important to recognize that treatment should not be rendered without a diagnosis and in these situations, the patient may have to wait and be reassessed at a later date or be referred to an endodontist.

Symptoms
I. Subjective Symptoms: Symptoms which are experienced and reported by the patients to the clinician.
II. Objective Symptoms: Symptoms which are ascertained by the clinician through various tests.

History and records
History taking forms an integral part of clinical evaluations. Basically questions concerning the patients (Table 1) Drugs to be used with caution. Pain -It may be defined as a noxious stimuli that causes discomfort.
Questions that should be asked are:  Patients may report that their dental pain is exacerbated by lying down or bending over. This occurs because of increase in blood pressure to the head, which results in increased pressure on the confined pulp [8,9]. *The first type of pain is caused by the excitation of the 'A' delta nerve fibres in the pulp.
*The second type of pain is caused by the excitation & slower rates of transmission of 'C' nerve fibres in the pulp.
The ability to localise pain is important. Sharp piercing pain in a tooth usually response to cold and is easy to localize. When the pain is defused, the patient describes an area of discomfort rather than a specific site. The duration of pain is often diagnostic.
a) The pulpal pain may last for a short duration only as long as the irritant is in contact with the tooth (acute reversible pulpitis ). Endodontics may not be necessary. b) If the pain persists for a longer duration, even after the removal of the irritant i.e. cold/hot, (irreversible pulpitis). Endodontic therapy is indicated. 3. most importantly using all possible barriers such as gloves, face mask and protective eye wear.

Objective symptoms
Percussion: Percussion of tooth initially with fingers (low intensity) and then later with increasing intensity using the handle of an instrument is undertaken to evaluate the status of the periodontium surrounding the tooth. A positive response differing from adjacent tooth, usually indicates the presence of periodontitis. When periodontitis occurs unrelated to periodontal lesions, it usually is a sequelae to pulpal necrosis. When apical periodontitis is present as a sequelae to periodontal lesions, the pulp is usually vital. While percussing a particular tooth, a more valid response can be obtained if at the same time, patient's body movement, reflex pain reactions or even an unspoken response is observed (Figure 1).

Mobility & Depressibility Testing
The mobility test is used to evaluate the integrity of the attachment apparatus surrounding the tooth.
a. The technique consists of moving the tooth laterally in its socket by using the handles of 2 instruments b. The test of depressibility consists of moving the tooth vertically in its socket. In a positive situation the chances of saving the tooth are very poor (Table 2). Endodontic treatment should not be carried out on teeth with grade 3 mobility unless the mobility is reduced (Figure 2).

Limitations of radiographs as diagnostic tools:
1. A lesion cannot be visualized if it is still in the cancellous bone. Only when it has penetrated into the cortical bone we get a radiolucent image. In other words….
a) A periapical lesion is usually larger than its image.
b) A pathologic area can be present yet be obscured by a plate of cortical bone.
c) An acute alveolar abscess in a tooth can have a normal radiographic appearance with no apparent radiolucency.

2.
A radiograph cannot be used to differentiate reliably among a chronic abscess, a granuloma or a cyst. An accurate diagnosis can only be made by histopathological evidence. The routinely accepted d/d features are: a) Granuloma: it is a dense radiolucency that is well defined.
b) Chronic alveolar abscess: it is a diffused radiolucency showing irregular pattern of bone destruction. c) Cyst: it is a radiolucent mass surrounded by thin line of radioopacity.
3. The presence of periapical radiolucency does not automatically indicate a diseased tooth.
a) It may superimpose an anatomical land mark such as maxillary sinus, medullary spaces, mental foramen, incisive foramen. b) In many instances it may also be a disorder that is not pulpaly related to Ameloblastoma, Malignant tumors, Periodontal cyst, Traumatic bone cyst.

A major limitation of radiography is that of different interpretations by different observers.
Advancements in radiography:

Digital intra oral radiography:
All X-ray images are in a digital format, viewed on a computer screen and thus requiring less than 1/3rd of the radiation doses administered when taking conventional X-ray film.

Digital OPG:
These are panoramic x-rays also used in digital format. With the latest software applications, one X-ray image allows the dentist to investigate many different aspects of your oral health (Figure 3-5). c) It was the first method to non invasively acquire images inside the human body that were not biased by superimposition of distinct anatomical structure. d) CBCT is an X-ray imaging approach that provides high resolution 3D images of the jaws & teeth.
e) CBCT shoots out a cone shaped x-ray beam and captures a large volume of area requiring minimal amounts of generated x-rays.
f) Within 10 seconds the machine rotates 360 degrees around the head and captures 288 static images ( Figure  6).  e) It requires only a single scan to capture the entire object, with reduced exposure time.

Micro -CT:
Recently, micro CTs, which essentially comprise a miniaturized design of cone beam CTs -typically used for non destructive 3D microscopy have become commercially available. The X-rayed measuring field is usually as small as 2 cubic cm. in volume.

Tuned Aperture Computed Tomography (TACT)
Improve accuracy in caries diagnosis because of its 3D or pseudo 3D capabilities.
TACT slices can be produced from an arbitrary number of X-ray projections, each exposed from a different angle. TACT is useful in detection of caries & recurrent caries, periodontal bone loss, periapical lesion, localization and TMJ bone changes.

MRI-Magnetic Resonance Imaging
This technique is based on the presence of specific magnetic properties found within atomic nuclei containing protons and neutron. Indications: 1. Aassessing diseases of TMJ.

Tumours.
Thermal Test: This test involves application of heat and cold to a tooth, to determine sensitivity to thermal changes.

A positive response to cold indicates pulp vitality
regardless of whether the pulp is normal or not. An abnormal response to heat indicates the presence of pulpal or periapical disorder requiring endodontic therapy.
2. When a reaction to cold occurs the patient can immediately point to the affected tooth, where as a positive response to heat on a single tooth results in a localized painful response which is momentarily delayed.

a) Technique of Heat Testing
1. Use of hot air, hot burnisher, hot guttapurcha, after isolation and drying.
2. After isolation with the rubber dam immersing the tooth in a coffee hot water with a syringe.

Advances in Dentistry and Oral Health
c) More current is needed in a tooth with reparative dentin, diminishing size of pulp cavity and fibrotic pulp.

Anaesthetic Test
a) This test is restricted to patients who are in acute pain at the time of examination and when the usual tests have failed to enable the clinician to identify the offending tooth b) The objective is to anaesthetize a single tooth at a time until the pain disappears, thus localizing the specific offending tooth.
c) Technique is to start with the most posterior tooth in the most particular arch and then shift to the mesial.

Test cavity
a) It allows one to determine pulp vitality and is performed only when all other tests have failed.
b) It is done by drilling the cavity in the tooth, through the DEJ OF AN un-anaesthetized. If a +ve response is there, medicated cement is filled in, and the adjacent tooth is drilled.

Techniques for detecting vertical crown/root fractures:
In vital teeth the most common reason for a fracture is trauma.
In non-vital teeth trauma may also be a contributory factor but endodontic treatment followed by overzealous post reinforcement is a common cause.

Of Endodontics
Pulpal Diagnoses

Apical Diagnosis
1. Normal apical tissues are not sensitive to percussion or palpation and radiographically, the lamina dura is intact and the PDL is uniform.
2. Symptomatic apical periodontitis represents inflammation of the apical periodontium, producing clinical symptoms involving a painful response to biting and / or percussion or palpation.
3. Asymptomatic apical periodontitis is inflammation and destruction of the apical periodontium that is of pulpal origin. It appears as an apical radioluscency.

4.
Chronic apical abscess is an inflammatory reaction to pulpal infection and necrosis characterized by gradual onset and discharge of pus.

5.
Acute apical abscess is an inflammatory reaction to pulpal infection and necrosis characterized by rapid onset, spontaneous pain, tenderness to percussion pus formation.

Classification of Endodontic Emergencies
Pre-treatment