Dental Lateral Canal Diagnosis

Pulpal Disease Diagnosis

• Lateral canals are portals of entry for toxins, and pulpal degeneration can occur if not diagnosed correctly.
• Thermal and electric pulp tests must be performed along with periodontal examination to distinguish between disease of pulpal and periodontal origin.

Thermal Test Techniques

• Heat test can be performed using different techniques such as:
  • Hot water
  • Hot burnisher
  • Hot gutta-percha
  • Hot compound
  • Polishing of crown with a rubber cup
• Cold test involves isolating the quadrant with the tooth to be tested and using:
  • Cold water
  • Cold air from a 3-way syringe directed against the crown of previously dried tooth
  • Ethyl chloride spray
  • Ice stick
  • CO2 snow

Electric Pulp Testing (EPT)

• The test should be first described to the patient, and teeth to be tested should be isolated with cotton rolls, saliva ejector, and air dried.
• The EPT tester should be checked for proper functioning, and an electrolyte (toothpaste) should be applied to the tooth surface.
• Avoid contact of the electrolyte or electrode with any restorations or the adjacent gingival tissue as this could lead to a false response.

Advantages of EPT

• Intensity of stimulus is comfortable to patients.
• Digital display of many EPT testers provides instant, easy, and reliable information.
• In some EPT testers, a red indicator light flashes on and off when maximum stimulus is reached.
• Gives a quantitative reading and can be compared with the normal reading of control tooth.

Anesthetic Test

• Restricted to patients who are in pain at the time of the test and when the usual tests have failed to help identify or localize the offending tooth.
• The objective is to anesthetize a single tooth at a time until the pain disappears and is localized to a specific tooth.
• If the source of pain cannot be differentiated (i.e., maxillary/mandibular), then a mandibular block is implemented.
• Further localization of the affected tooth is done by an intraligament injection.

Transillumination Test

• Light from a fiberoptic is applied from the buccal surface to illuminate the tooth to detect fractured lines when present.
• From the contact area to detect contact caries.

Biting Test

• Placing the pointed end on each cusp and then having the patient bite and release.
• A normal, healthy tooth will have no pain.
• An orangewood stick is placed on the occlusal/incisal aspect (on each cusp in case of posteriors) of the tooth, and the patient is asked to bite.

Staining

• Remove the filling from the suspected tooth and place 2% Iodine (or other stain) in the cavity preparation.
• The iodine stains the:
  • Fracture line dark.
  • Canal orifice.

Guttapercha Point Tracing

• Can localize the endodontic lesion to the specific tooth.
• Aids in the differential diagnosis between a periodontal and an endodontic lesion.
• Placing a guttapercha point through the sinus/fistula tract and taking a radiograph.

Radiographs Importance

• Provides information on the extent of caries into the pulp.
• Number of root canals and accessories.
• Course and shape of the canals.
• Length of the root.
• Calcifications.
• Resorptions.
• PDL status.

Diagnosis

• Is a process of determining the nature of a disease.
• It is very important for proper treatment.
• Differential diagnosis: is the process of differentiating between similar diseases.
• Sequential agreement is very important for correct differential diagnosis:
  • Proper knowledge of the disease.
  • Skill and art on how to apply proper diagnostic methods.

Clinical Examination

• Extra oral examination:
  • Facial asymmetry.
  • Localized swellings.
  • Changes in color, bruises/ scars.
  • Lymphadenopathy (groups of lymph nodes).
• Visual and tactile inspection:
  • Soft tissue:
    • Color.
    • Contour.
    • Consistency.
  • Hard tissue:
    • Color.
    • Contour.

Medical Conditions Requiring Modification of Treatment and Consultation

• Cardiovascular:
  • High & moderate risk of Endocarditis.
  • Pathologic heart Murmurs.
  • Hypertension.
  • Unstable angina.
  • Recent myocardial infarction (6 months).
  • Arrythmias.
  • Poorly managed congestive heart failure.
• Pulmonary: COPD, Asthma, Tuberculosis.
• GIT & Renal: End stage renal disease, Hemodialysis, Viral hepatitis (A,B,C,E), Alcoholic liver disease, Peptic ulcer disease, Endocrine & Hematologic: STDs: HIV & AIDS, Diabetes mellitus, Adrenal insufficiency, Pregnancy, Bleeding disorders, Cancer & leukemia, Osteoarthritis, rheumatoid arthritis, SLE.

Limitations of Radiographs

• 2D image of a 3D object.
• State of pulpal health cannot be ascertained.
• P/A pathology is evident only after much destruction (33%).
• Early vertical root fracture cannot be diagnosed.
• Bony trabeculae misinterpreted for horizontal root #.
• Extend of caries is usually less than the actual extent as is true for P/A pathology.

Anatomic Structure Can Mimic P.A. Pathology

• Canal seems to disappear due to narrowing of canal space or overlapping of the roots on the radiograph.

Other Radiographic Methods

• Xeroradiography.
• Radiovisiography (RVG).
• Cone beam computerized tomography (CBCT).
• Magnetic Resonance Imaging (MRI).
• Ultrasound imaging.

CBCT

• Basic 3 sections.
• Check the cervical cross-sectional shape.

Trauma and Habits

• Trauma is a common cause of pulp disease in children, resulting from violent blows to the tooth during fights, sports, or household accidents.
• Habits such as opening hard objects with teeth, compulsive bruxism, nail biting, and thread biting can also lead to pulp disease.

Dental Procedures

• Certain dental procedures can injure the pulp, including crown preparation, over-cutting with dull burs, and reduced cooling system of turbines.
• Removing dentin for a crown preparation, curing materials needed for provisionalization, and microleakage under a temporary crown can contribute to possible pre-existing pulpitis.

Pathologic Wear

• Attrition is natural tooth-to-tooth friction that occurs when you clench or grind your teeth, often involuntarily during sleep.
• Abrasion is physical wear and tear of the tooth surface that happens with faulty brushing or hard toothbrushes, fingernails, and chewing tobacco.
• Abfraction is the pathological loss of tooth substance caused by biomechanical loading forces, resulting in flexure and failure of enamel and dentin at a location away from the loading.
• Erosion occurs chemically when acidic content hits the tooth surface, such as with certain medications, highly acidic foods, and frequent vomiting.

Cracked Tooth Syndrome

• Incomplete fracture through the body of the tooth can be due to excessive masticatory forces, causing symptoms ranging from mild pain to severe pain.
• The pulp of the tooth may become necrotic in severe cases.
• Patients may feel pain when biting on a cotton or rubber wheel, and radiological manifestations may include a J-shaped lesion in the late stage.

Thermal Injuries

• Thermal injuries can occur due to cavity preparation, including:
  • Deeper cavity preparation
  • High-speed engines
  • Poor coolant system
  • Extensive cavity
  • Excessive cutting of dentin
  • Dull burs
  • High pressure with cutting

Polishing Injuries

• Polishing with dry powders can lead to temperature rise and heat conduction by restoration.
• Heat conduction can occur through very deep metallic restorations close to the pulp without any intermediate cement base.

Electrical Injuries

• Galvanic current from dissimilar metal fillings can cause pulp disease.

Chemical Causes

• Pulpal inflammation can occur due to:
  • Citrus ingestion
  • Acid etchants used to expose dentin
  • Dehydrating chemicals for sterilizing/drying
  • Gastrointestinal problems that produce repeated exposure of teeth to gastric acids

Bacterial Causes

• Bacterial invasion can occur through:
  • Direct invasion through dentin
  • Invasion through open blood vessels or lymphatics associated with periodontal disease
  • Invasion through blood (anachoretic effect) during infectious diseases or transient bacteremia

Idiopathic Causes

• Aging can cause pulp disease, including:
  • Atrophy of the pulp
  • Decrease in the number and size of cells
  • Increase in collagen fiber content
• Internal resorption can occur due to:
  • Trauma
  • Caries
  • Ortho treatment
  • Infection/pulpitis
  • Extreme heat

Internal Resorption

• Internal resorption is a localized internal dentin destruction due to odontoclastic activity.
• Clinical appearance includes a pink spot on the crown.
• Treatment involves endodontic treatment to arrest the progression of the resorption.

External Resorption

• External resorption occurs when the resorptive tissue is supplied by blood vessels coming through the apex.
• Treatment involves removal of the cause, and in cases where it is accessible, RCT and composite restoration.
• In cases where it is non-accessible, surgical access and correction by MTA or BIODENTINE are necessary.

Pulpitis

• Pulpitis is inflammation of the pulp, and can be classified as:
  • Reversible pulpitis (acute or chronic)
  • Irreversible pulpitis (acute or chronic)
  • Pulp degeneration (calcific or atrophic)
  • Pulp necrosis

Reversible Pulpitis

• Reversible pulpitis is a mild to moderate inflammatory condition that can return to its normal position after removal of stimuli.
• Characteristics include:
  • Sharp pain of short duration
  • Pain subsides after stimulus is removed
  • The affected tooth responds to cold
  • Tooth responds to electric pulp testing at very low levels of current than control tooth