How does one decide whether a crack/craze line on an asymptomatic tooth should be attempted to be removed, either with a restoration or a crown?
Dr. Mary Dabuleanu of Dabuleanu Dental, in collaboration with Dr. Suham Alexander, Oasis Clinical Editor, provided the following quick initial response
CRAZE LINE vs. CRACK
A craze line is a crack that involves only enamel and is usually asymptomatic. Most teeth have craze lines. Unless the crack is of aesthetic concern, no treatment is necessary, Fig 1a.
A true crack usually involves the enamel, dentin and eventually the pulp. These cracks begin occlusally and travel sub-gingivally. The crack may occur mesio-distally or bucco-linugally, Fig 1b. As the crack extends apically, the pulp becomes involved due to the more central location of these cracks.
CRACKED TOOTH SYNDROME
Patients with “cracked tooth syndrome” usually describe pain with chewing a certain way or may experience pain to cold on the affected tooth. The severity of symptoms depends on the degree of pulpal inflammation and subsequent treatment depends on the pulpal diagnosis and on the extent of the crack.
Krell et al (2007) studied the clinical outcomes of cracked teeth diagnosed with reversible pulpitis. They found that 20% of teeth with cracks, diagnosed as reversibly inflamed and receive a crown, will require root canal treatment within 6 months.
Treatment also depends on the extent of the crack and whether the surrounding periodontium has been affected (i.e. probing greater than 3 mm).
A crack with an associated periodontal pocket usually has a poor prognosis and extraction is advisable.
Teeth with cracks, even those that extend vertically to the CEJ, may be considered for root canal treatment and a crown if there is no deep periodontal probing surrounding the location of the crack. Also, the patient must be fully prepared that all cracked teeth have a questionable long term prognosis as cracks may continue to propagate despite our best efforts to retain these teeth.
When root canal treatment is performed on these teeth, placing an orthodontic band helps to prevent further crack propagation in the interim before a final crown is placed.
Tan et al (2006) assessed the survival rate of root filled cracked teeth over a 2 year period. All teeth received a crown or an orthodontic band. The two year survival rate of these teeth was 85.5%. Pre-existing periodontal pockets, the presence of multiple cracks and terminal teeth in the dental arch significantly affected tooth survival.
Moreover, Kim et al (2013) have outlined a treatment protocol commonly used for cracked teeth depending on the stage of pulpal pathology present. A treatment algorithm is shown in Figure 2.
In summary, cracks present both a diagnostic and treatment dilemma. The decision to treat and restore these teeth involves a careful discussion with the patient of the prognosis time and cost. When treated, a good number of cracked teeth can remain functional for a considerable time.
- Kim Sin-Young, Kim Su-Hyun, Cho Soo-Bin, Lee Gyung-Ok, Yang Sung-Eun. Different Treatment Protocols for Different Pulpal and Periapical Diagnoses of 72 Cracked Teeth. JOE Volume 39 No 4, April 2013: 449-452
- Krell Keith, Rivera EM. A Six-Year Evaluation of Cracked Teeth Diagnosed with Reversible Pulpitis: Treatment and Prognsosis. JOE 2007; 33:1405-1407
- Cracking the Cracked Tooth Code: Detection and Treatment of Various Longitudinal Fractures. Endodontics: Colleagues of Excellence Summer 2008: 1-8.
Dr. Mary Dabuleanu
Mary Dabuleanu obtained her Doctorate of Dental Surgery from the University of Toronto in 2002. She continued her training in Montreal, Quebec, where she completed a full year general practice residency program through McGill University at the Royal Victoria Hospital.
Following a few years in general practice, Dr. Mary Dabuleanu received her Master of Science degree and certificate in Endodontics from The University of Detroit Mercy Detroit, Michigan in 2007. Dr. Mary Dabuleanu is a Fellow of the Royal College of Dentists of Canada FRCD(C).
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