ENDO TRIBUNE The World’s Endodontic Newspaper · U.S. Edition www.endo-tribune.com February 2010 Vol. 5, No. 2 Troubleshooting calcified canals: clinical case review By Richard E. Mounce, DDS The patient pictured in figure 1 was referred because the first clinician could not locate the canal(s). The patient had pain when chewing on #13 and mild spontaneous pain leading to a diagnosis of a non-vital pulp before referral. The referring doctor accessed the tooth without canal location. The patient was subsequently referred. This clinical case review will discuss the clinical findings, management and potential complications treating this case from a treatment planning perspective and discuss the clinical technique and materials used. Upon referral the patient was asymptomatic and there was no swelling. The tooth was mildly percussion sensitive, and within normal limits to palpation, mobility and probings. Radiographic assessment of #13 showed open crown margins and calcified canals. Dr. George Huang Broke a tooth? Grow another! To all those who have made deals with the tooth fairy in the past: You probably sold your teeth below their fair value. Herbert Schilder Professor in Endodontics and Director of the Postdoctoral Program in Endodontics at Boston University Henry M. Goldman School of Dental Medicine (GSDM) Dr. George Huang said those baby teeth and extracted third molars we are throwing away hold valuable dental stem cells. “Our team found for the first time that we can reprogram dental stem cells into human embryonic-like cells called induced pluripotent stem (iPS) cells, which may be an unlimited source of cells for tissue regeneration,” Huang said. So far, scientists have had luck creating iPS cells from various cells in mice easily, but this hasn’t been as easy in humans, until more recently. All three types of human dental stem cells the GSDM team tested are easier to reprogram than fibroblasts, which previously seemed to be g ET page 2B Risk factors in endodontic management of #13 Fig. 1: The case (#13) before access at the general practitioner’s. #13 is at moderate risk of cervical perforation if the access were to veer off a coronal to apical straight line. Every effort must be made to continue dentin removal in line with the true canal until the canals are located. Excessive removal of dentin at the cervical region of the tooth could, in addition to perforation risk, make the coronal tooth structure susceptible to coronal and, ultimately, vertical root fracture. The anticipated master apical taper and master apical diameter of the case should be determined before starting. In this clinical case, the anticipated master apical taper was .08 and the anticipated master apical diameter was #40 or possibly a #50 ISO tip size. The porcelain was at risk of fracture during access if the coronal opening needed expansion significantly beyond its current size. In order to gain the greatest visual and tactile command over access, the use of enhanced visualization and magnification is essential. The surgical operating microscope (SOM) (Global Surgical, St. Louis, Mo.) is optimal and in this case a suitable substitute would be the 4.8x Class IV HiRes Plus loupes with a light source (Orascoptic, Middleton, Wis.). While a comprehensive discussion of the use of the SOM or loupes is beyond the scope of this paper, it is noteworthy that once the temporary filling is removed, the texture and color of the dentin should be evaluated to determine if the clinician is in line Fig. 2: The case after access at the referring doctors’. AD with the canal or off track. The depth of dentin removal in the access is critical. If the clinician has progressed 7 to 8 mm in access and the canal is not located, it is a virtual certainty that the access is misdirected and perforation risk is extreme. Once the canal is located, the clinician faces the risk of canal blockage if canal enlargement is mismanaged. The use of large orifice openers (.12, .10 or .08) or Gates Glidden drills (as g ET page 3B