tooth fracture Flashcards
A. How is a fractured tooth diagnosed?
There are multiple ways to determine whether or not a tooth is fractured. It is important to start with a good dental history of the tooth. A clinical exam should include a bite stick, ice for vitality testing, and a periodontal probing to check for deep narrow pockets.
A radiographic exam is important to check for periapical rarefactions or possibly to reveal a fracture itself if it is large enough.
Finally, a stain (methylene blue), or trans-illumination may be used to visualize the fracture. Sometimes the tooth may be mobile or a sinus tract may have developed due to fracture necrosis.
If a tooth is non-vital with minimal or no restorations, suspect a crack or fracture (Berman & Kuttler 2010).The older the tooth, the more susceptible it is to fracture (Berman & Kuttler 2010). Cracked teeth are more commonly found in lower molars, followed by maxillary pre- molars (Cameron 1976). Another study found that lower 2nd molars were more likely to have cracks after root canal treatment (Kang, Kim & Kim 2016)
B. What are the types of cracks one may see in a suspected tooth fracture?
According to the American Association of Endodontics (Rivera & Walton 2008), there are five categories of crack:
• Craze lines: Only involving the enamel;
• Split tooth: Complete fracture through the tooth, usually centered mesial to distal;
• Fractured cusp: Usually non-centered and affect- ing one cusp;
• Cracked tooth: An incomplete fracture that extends from the crown to the subgingival area of the tooth; and
• Vertical Root Fracture (VRF):This may be sympto- matic or non- symptomatic.The majority of the VRFs are associated with root-filled teeth. It may be a complete or an incomplete fracture.
C. What is the prognosis for a cracked tooth?
The prognosis for a cracked tooth is always going to be questionable (Rivera & Walton 2008). The prognosis is always better if the crack does not extend to the pulp chamber floor (Turp & Gobetti 1996; Sim et al. 2016). Vital is better than necrotic (Turp & Gobetti 1996).The quality of the restoration and whether a full coverage crown may cover the crack and other defects are considerations (Rivera & Walton 2008), as is whether an abscess or radio- graphic rarefaction is present prior to treatment. These two factors would lower the prognosis of the tooth in question (Berman & Kuttler 2010). One study found that cracked teeth had a two-year survival rate of 85.5% (Tan et al. 2006). Another study found that after five years, the survival rate of root-filled cracked teeth was 92%, with the odds of extraction increasing if the cracks were in the root (Sim et al. 2016). Finally, a recent study from Korea showed a 90%, two-year survival rate for a cracked tooth, probing depths greater than 6 mm being a significant factor in the prognosis (Kang et al. 2016).
D. How is a cracked tooth treated?
After removal of all caries or previous restora- tions, the extent of the defect must be determined. If the crack or fracture transverses the pulpal floor or goes too deep subgingivally, then extraction of the tooth must be considered (Sim et al. 2016). If the tooth is vital with no narrow probing defects, abscesses, or periapical rarefactions, then restoring the tooth may be considered, along with endodontic therapy if needed, depending on the health of the pulp (Sim et al. 2016).
If a horizontal fracture occurs due to trauma, the position of the defect and the vitality of the pulp must be evaluated (Andreasen 1970). If the fracture is high enough, the coronal portion may be removed to see if a crown lengthening procedure along with endodontic therapy might salvage the tooth. If the defect is in the apical third, then an RCT to the coronal portion of the root is indicated (Andreasen 1970). If, however, the apical third has a rarefaction, an osteotomy may be performed to remove the infected piece.
Four types of outcome occur with intra-alveolar root fractures: (1) healing with calcified tissue; (2) interposition of connective tissue; (3) interposition of connective tissue and bone; and (4) interposition of granulation tissue without healing (Kim et al. 2016).
E. What is the incidence rate of fractures?
The incidence rate of VRFs is less than 3% (Zachrisson & Jacobsen 1975), and the rate of crown fractures for all dental trauma is about 2% (Macko et al. 1979). Hand instrumentation does not produce dentinal cracks (Yoldas et al. 2012).
The more tooth structure is removed, the more likely a fracture will occur. It takes about half of the dentin to be removed before cracks begin to appear (Wilcox, Roskelley & Sutton 1997). A study found that VRFs tend to be more prevalent in maxillary premolars, mandibular molars, women, and individuals over the age of 40. VRFs are more difficult to diagnose because they do not always have deep probing depths (Cohen et al. 2006).
