Periapical central giant cell granuloma: a potential endodontic misdiagnosis.

This retrospective study ascertained the incidence and clinicopathologic features of central giant cell granulomas (CGCGs) associated with teeth with necrotic pulps or teeth that had received previous endodontic treatment and determined whether periapical CGCGs can result in endodontic misdiagnosis. Clinical and histopathologic data of biopsy specimens diagnosed as CGCG were collected from the archives of the Oral Pathology Laboratory, Temple University, and were reviewed. Over the 9-year period, 16 of 79 cases (20%) of CGCG were associated with a tooth that had a history of pulp necrosis. Of those, 14 (88%) were associated with previous root canal treatment. The data from this series of 79 cases of CGCG also showed that CGCGs were less common in women, less common before age 30, and did not cross the midline of the jaw as often as previously reported. Clinical and histopathologic data were compared from (1) CGCGs associated with teeth with vital pulps or that occurred in edentulous areas; (2) CGCGs associated with teeth with necrotic pulps; and (3) 194 cases of periapical granulomas and radicular cysts. These data strongly suggest that CGCGs associated with teeth with necrotic pulps are not directly related to periapical inflammation and may be misdiagnosed as endodontic lesions. Posttreatment follow-up and routine submission of periapical surgical specimens are emphasized.

Thermafil retreatment using a new "System B" technique or a solvent.

The solid plastic carrier in the Thermafil obturation system must be removed to facilitate retreatment. The purpose of this study was to compare the efficacy and time required to retreat canals obturated with Thermafil with plastic carriers using a new technique based on the System B HeatSource or a solvent. Fifty-two extracted human mandibular premolars with single canals were instrumented and then obturated with Thermafil with plastic carriers. After 2 wk storage at 22 degrees C and 100% humidity, they were randomly divided into 2 groups of 26 teeth each. Group 1 teeth were retreated using chloroform and hand files, whereas teeth in group 2 were retreated with a new technique using the System B HeatSource. The end point of retreatment was defined as complete removal of the plastic carrier. The time required for retreatment was recorded. Then, the apical 5 mm segment of each root was sectioned horizontally at 1 mm intervals and each section digitally imaged. The total area of the canal and the area of the canal occupied by gutta-percha and sealer were measured using NIH image software. Data were analyzed using an unpaired t test. The mean time for retrieval of the plastic carrier was significantly less for the System B technique (1.8 min) than for the solvent technique (3.6 min) (p < 0.001). The difference between the two groups in the amount of filling material (carrier, gutta-percha, and sealer) removed was not significant (p > 0.05).

Evaluation of pigmented intraorifice barriers in endodontically treated teeth.

The purpose of this study was to evaluate the effectiveness of three pigmented glass ionomer cements used as intraorifice barriers to prevent coronal microleakage. One hundred ten extracted mandibular human premolars were divided into four experimental groups of 25 teeth each and two control groups of 5 teeth each. The experimental teeth were instrumented and obturated using thermoplasticized gutta-percha and AH26 sealer. Group 1 teeth received no further treatment. Teeth in groups 2 through 4 had 1 of 3 pigmented glass ionomers (Vitrebond, GC America, and Ketac-Bond) placed as an intraorifice barrier. Positive control teeth were instrumented but not obturated. The negative control teeth were instrumented, obturated, and externally sealed with epoxy resin. The coronal 3 mm of each root was sealed into the lumen of an 18-mm segment of latex surgical tubing. After the apparatus was sterilized, 2.0 ml of a 24 h growth of Proteus vulgaris in trypticase soy broth (TSB) was placed in the coronal reservoir of the tooth. The inoculated apparatus was placed into a presterilized test tube containing 1.5 ml of TSB and incubated for 90 days at 37 degrees C. The TSB in the lower reservoir was observed daily for turbidity, which would indicate leakage along the full length of the obturated root canal. To determine if differences in microbial leakage occurred among the four experimental groups, Pearson's chi 2 and Fisher's exact tests were performed. The confidence level was set at 95%. The positive and negative controls validated the microbial testing method. The teeth without an intraorifice barrier leaked significantly more than teeth with Vitrebond intraorifice barriers (p < 0.05). The difference in leakage among the experimental glass ionomer barriers was not significant (p > 0.05).