ABSTRACT
Objective:To study the factors of nickel titanium instrument(NTI)seperation in posterior tooth root canal therapy.Meth-ods:NTIs were used in 1 498 patients with 1 562 involved posterio teeth and 3 518 root canals for RCT from Jun.2009 to May.2012. The relation of instrument seperation(IS)with gender,age,tooth position,working years of the dentists,bending degree of the in-volved tooth canal and the NTI form was analyzed statistically.Results:68 out off 1 198 applied NTIs(5.68%)were seperated in cal-nal preparation.Single factor analysis showed that IS incidence was not statistically different between male and femal(χ2 =0.013,P >0.05),it was statistically different among the patient ages(χ2 =-354.258,P <0.05),between molar and premolar(χ2 =-201.344,P <0.05),among working years of the dentists(χ2 =13.763,P <0.05),bending degree of involved teeth(χ2 =22.414,P <0.05),times of NTI uses(χ2 =16.807,P <0.05),taper of NTIs(χ2 =18.283,P <0.05)and diameter of NTIs(χ2 =21.312,P <0.05).Logistic analysis showed that age,tooth position,working years of dentists,bending degree of involved tooth canal,frequency of NTIs applica-tion and NTI form were independent risk factors for NTI seperation.Conclusion:Dentists should take appropriate technique and stand-ard operation sequence to reduce the incidence of nickel titanium instrument seperation.
ABSTRACT
Objective To investigate appropriate diagnosis and treatment of solitary fibrous tumor of the pleura (SFTP).Methods Clinical and pathological data of ten patients treated in our hospital from 2002 to 2007 were reviewed. Results Our series consisted of three men and seven women. In two patients correct diagnosis was made before operation through ultrasonography-gnided core needle biopsy. All the patients were treated surgically including three resected by video-assisted thoracic surgery (VATS). Histopathologically, five tumors were malignant and the other five were benign. Immunohistochemical staining showed malignant SFTP (3/5) were less frequently positive for CD34 than benign group (5/5). Nestin was only detected in malignancies (2/5), which were negative for CD34. Except for one, all patients were followed-up for 6 to 35 months (mean 17.3 months). One patient experienced a recurrence and one died of brain metastasis. Conclusion Ultrasonography-guided core needle biopsy combined with immunohistochemical analysis is a safe and rapid method to provide a confirmatory diagnosis before surgery. For smaller, pedunculated tumors, VATS may be a bettor approach. Besides, we speculated CD34-negative and nestin-posifive might be a malignant marker for SFTP.