A new in vitro method to evaluate radio-opacity of endodontic sealers.

OBJECTIVES: To evaluate a new method for assessing the radio-opacity of endodontic sealers and to compare radio-opacity values with a well-established standard method. METHODS: The sealers evaluated in this study were AH Plus(®) (Dentsply DeTrey GmbH, Konstanz, Germany), Endo CPM Sealer (EGEO SRL, Buenos Aires, Argentina) and MTA Fillapex(®) (Angelus Dental Products Industry S/A, Londrina, Parana, Brazil). Two methods were used to evaluate radio-opacity: (D) standard discs and (S) a tissue simulator. For (D), ten standard discs were prepared for each sealer and were radiographed using Digora(®) phosphor storage plates (Soredex; Orion Corporation, Helsinki, Finland), alongside an aluminium stepwedge. For (S), polyethylene tubes filled with sealer (n = 10 for each) were radiographed inside the simulator as described. The digital images were analysed using Adobe Photoshop(®) software v. 10.0 (Adobe Systems, San Jose, CA). To compare the radio-opacity among the sealers, the data were analysed by ANOVA and Tukey's test, and to compare methods, they were analysed by the Mann-Whitney U test. To compare the data obtained from dentin and sealers in method (S), Student's paired t-test was used (=0.05). RESULTS: In both methods, the sealers showed significant differences, according to the following decreasing order: AH Plus, MTA Fillapex and Endo CPM. In (D), MTA Fillapex and Endo CPM showed less radio-opacity than aluminium. For all of the materials, the radio-opacity was higher in (S) than in (D). Compared with dentin, all of the materials were more radio-opaque. CONCLUSIONS: The comparison of the two assessment methods for sealer radio-opacity testing validated the use of a tissue simulator block.

Evaluation of 242 consecutive parotidectomies performed for benign and malignant disease.

Between 1987 and 1992, one surgeon performed 242 parotidectomies in 229 patients. Among 97 patients with benign disease, pleomorphic adenoma (46) and sialo-adenitis (28) predominated, while metastatic melanoma (22) and squamous cell carcinoma (21) were the most common diagnoses among 132 patients with malignancy. The extent of parotidectomies were: 114 'appropriate' resections, 77 complete superficial parotidectomies, 35 near-total conservative and 14 radical total resections. The facial nerve was sacrificed in 19 operations and reconstructed in four. One hundred and five patients had a concomitant neck dissection and 45 patients had adjuvant radiotherapy. Postoperative facial nerve function was normal in 90% of patients with localized tumours and 55% of patients overall. Patients with sialo-adenitis or deep lobe tumours and those having a neck dissection were at greatest risk of facial weakness despite nerve preservation. At a median follow up of 34 months, 13 patients had developed tumour recurrence and attempts at salvage surgery have generally been disappointing.