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Diagnosing and Restoring the Cracked Tooth

LCDR Carol Barone-Smith, NNDC, Bethesda

Cracked Tooth Syndrome

Related Terms:

Incomplete fracture

Greenstick fracture

Tooth structure crack

Cracked tooth syndrome: an incomplete fracture of a tooth causing pulpal and/or periodontal symptoms.

The patient has a history of fracturing other teeth.

Lower second molars are most common teeth to fracture.

Fracture is usually in the mesial-distal direction.

Patients have short square faces with muscular jaws.

75% of cases have vital pulps.

Perio pocket may develop along the line of fracture.

Only 20% of patients are less than 40 years old.

Wear facets and plunger cusps are common.

Restoration is long standing (5-10 years)

Deficient coalescence

Developmental grooves

Occlusal and parafunctional factors

Restorative factors:

Restored vs. unrestored

preparation width and depth

pins

overcarving

Thermal cycling

Tooth morphology and position

Trauma

Endodontic factors:

lateral condensation pressure

inadequate support of cracked teeth

Prosthetic factors:

tight posts

excessive tooth reduction

post corrosion

inadequate ferrule effect

inadequate venting

Lingual barbell

Erratic pain on mastication/biting pain

Inability to localize

Inability to explain the complaint

Thermal sensitivity especially to cold

Sensitivity to sweet/sour things

Usually no pain to percussion

Usually radiographs are inconclusive

Long history of pain

Depends on the location, direction, and extent of the crack.

If the pulp is involved:

signs and symptoms of irreversible pulpitis

necrosis with periradicular pathosis.

If caught early and treated appropriately:

cracks can be stopped or slowed down

prevent tooth loss

improve the chances of saving the tooth

Confirm the presence of a crack

Determine the type of crack

Formulate an appropriate treatment plan

Dental history

Subjective examination

Tactile examination

Bite tests

Periodontal Probing

Radiographs

Restoration removal

Staining

Transillumination

Endodontic evaluation

Surgical assessment

Endodontically treated teeth:

symptoms caused by the affected periodontium

Vital teeth:

confirm the presence or absence of a crack

do further pulpal and periodontal testing

Patients delay seeking treatment -

1 month to several years

Check for:

repeated occlusal adjustments with no conclusive diagnosis

history of periodontal disease

history of other cracked teeth

Point to offending tooth

Bite a hard object?

Damaging habits?

Check for:

enlarged masticatory muscles

wear facets

excessive occlusal stresses

crazing lines / darker cracks

cracked restorations / unusual gaps

Scratch the tooth surface

Palpate the gingiva around the tooth -

underlying dehiscence or fenestration

 

Instruments to focus biting pressures on cusps:

tooth slooth, cotton wood stick, saliva ejector

Use controls

Pain during biting or chewing is classic

Absence of pain during biting does not rule out a crack

Percussion: lateral tap on cusps

Probe the circumference of the tooth

Narrow pocket

Cracks rarely show up

Never see mesial-distal cracks

Buccal-lingual cracks -

see if separation of segments

crack at same angle as radiograph

Radiographic evidence more likely as crack progresses

Take periapical radiographs from different angles

Take bitewings

Thickened PDL

Diffuse longitudinal radiolucency -

J-shaped

Existing restorations with pins/posts

Examine remaining cavity

Examine mesial and distal marginal ridges

Cracks disclosed through staining

Methylene blue -

incorporated into IRM

place for one week, remove, check for stained cracks

Light source applied directly to tooth

A crack will block light

Structurally sound teeth -

craze lines

transmit the light throughout the crown

Electric pulp test/Endo ice

Percussion/palpation sensitivity

Thermal testing -

rubber dam

pain greater than 5 seconds = suspect

Visual examination of the root surface

Early detection of untreatable situations

Inform patient this is diagnostic procedure

Craze line

Fractured cusp

Cracked tooth

Split tooth

Vertical root fracture

Affect only the enamel

In posterior teeth -

crossing marginal ridges

extending along buccal and lingual surfaces

Anterior teeth -

long vertical lines

Cause no pain

Differentiated by transillumination: crown will light up. Light is blocked by cracks.

Easiest to identify and treat

Treatment has best prognosis

Due to weakened marginal ridge

Common for crack to have a mesial-distal and buccal-lingual component

Generally one cusp affected

May remove the restoration, stain the tooth, transilluminate the crack or use magnification.

Class II restorations or extensive caries

Weakened marginal ridges

Mild pain which occurs only to stimulus

Bite tests -

elicits brief, sharp pain,

release of biting pressure

Percussion may identify the crack

Radiographs inconclusive

Remove the affected cusp

Restore with full coverage

Root canal treatment when the crack affects the pulp chamber.

Cracks usually mesiodistal

Cracks cross both marginal ridges

Tooth is split into two segments

Usually the result of long term progression of a cracked tooth

Identified readily with -

apparent crack

segments that separate when probed

Patients complain  -

pain to chewing

significant soreness of mandible or gingiva

Never saved intact

Position and extension of crack will determine prognosis and treatment

The smaller segment can be removed and the remaining segment restored

Extraction indicated if crack extends further

Begin in the root

In the buccal-lingual plane

May extend to buccal and lingual surfaces

Minimal signs and symptoms

Periradicular pathosis

Treatment:

extraction or

removal of cracked root

Mimics:

Periodontal disease

failed root canal treatment

Post placement

Excessive compaction force during obturation

Roots that fracture more often:

wide facially and lingually but thinner mesially and distally

Mandibular incisors and premolars, maxillary second premolars, mesiobuccal roots of maxillary molars, mesial and distal roots of mandibular molars.

Signs and Symptoms:

mild

may be mobile

may see periodontal abscess or have history of one

history of root canal treatment

some normal probing depths/most allow deep probing in narow or rectangular patterns

Inconclusive percussion and palpation tests

Radiographic evidence:

visible separation of segments

bone resorption along root surface

Surgical assessment for conclusive diagnosis -

Characteristic: "punched-out" oblong bony defect filled with granulomatous tissue overlying the root

Extraction

Root resection

Hemisection

No method practical or effective long term

Post and core restorations may cause root stress

Insufficient coronal tooth structure:

passive prefabricated metal posts

proper length ,size and design

Carbon fiber posts:

carbon embedded in an epoxy resin

post and restoration respond like dentin

The crack extends from the occlusal surface of the tooth apically

Crack more centered occlusally than cusp fracture

Most common in mandibular molars followed by maxillary premolars

 

May cross marginal ridge(s)

usually mesiodistal

Does not occur in anterior teeth, rarely in mandibular premolars

Signs and symptoms will vary depending on the progress of the crack

Early stages:

invisible to the eye

cannot disclose with staining

Acute pain on mastication

Sharp brief pain to cold

May progress to involve pulp or periapical tissues

Crack will block and reflect light

Protect the tooth prior to endodontic treatment:

band

temporary crown

Cores of dentin bonding materials -

prevent crack from spreading

Avoid excessive wedging forces with obturation

Questionable: Inform patient

Best if no crack is visible or crack does not extend to the pulpal floor

Best if rendered pain free by banding or temporary crown

Cracks may progress and separate

Splint clinical crown together

Prevent crack propagation

Multidisciplinary approach

Varies depending on the extent and location of the crack

Root canal treatment

full cuspal coverage

Periodontal Probing:

absence of a defect does not rule out crack

deep probing = poor prognosis

Radiographic Examination:

findings depend on pulpal and periradicular status

vertical or furcal bone loss = severe crack

Pulp and Periradicular tests -

pain to chewing only:

band or temporary crown.

If banding resolves pain to chewing:

full coverage.

If pain continues to chewing after banding:

further eval of pulpal and periradicular status.

Thermal sensitivity -

crack extends near pulp

root canal treatment

crown

Endodontic Access: Cracked pulpal floor

do not chase extent of crack

stain access to disclose crack

magnification and illumination may confirm crack

Crack partially across chamber floor:

band or temporary crown

root canal reatment

full cuspal coverage

Crack extends full width of floor:

very poor prognosis

extraction

Crack across chamber floor and deep perio defect:

prognosis is hopeless

Orthodontic band

Copper band

Stainless steel crown

Onlay amalgam using slots and grooves

Composite restoration

Temporary crown

Adjust proximal contact

Lute band with polycarboxylate cement

Adjust occlusion

Wait 1-3 weeks after immediate stabilization and evaluate

If pain has persisted, RCT

If pain subsided, permanent restoration:

full crown coverage

Occlusal clearance

Proximal clearance

Use slots and grooves

Use pins as last resort

Cuspal coverage

Contacts in maximum intercuspation

Retentive/resistance features

 

Prompt full cuspal coverage of endodontically treated molars and premolars will help prevent fractured cusp, cracked tooth, and split tooth!

Awareness of cracked tooth syndrome

Current restorative standards

Management of parafunctional habits and/or occlusal disharmony

Early diagnosis

Aggressive Treatment

Prevention