Evaluation of apical canal shapes produced sequentially during instrumentation with stainless steel hand and Ni-Ti rotary instruments using Micro-computed tomography / 대한치과보존학회지

OBJECTIVES: The purpose of this study was to determine the optimal master apical file size with minimal transportation and optimal efficiency in removing infected dentin. We evaluated the transportation of the canal center and the change in untouched areas after sequential preparation with a #25 to #40 file using 3 different instruments: stainless steel K-type (SS K-file) hand file, ProFile and LightSpeed using microcomputed tomography (MCT). MATERIALS AND METHODS: Thirty extracted human mandibular molars with separated orifices and apical foramens on mesial canals were used. Teeth were randomly divided into three groups: SS K-file, Profile, LightSpeed and the root canals were instrumented using corresponding instruments from #20 to #40. All teeth were scanned with MCT before and after instrumentation. Cross section images were used to evaluate canal transportation and untouched area at 1- , 2- , 3- , and 5- mm level from the apex. Data were statistically analyzed according to' repeated nested design'and Mann-Whitney test (p = 0.05). RESULTS: In SS K-file group, canal transportation was significantly increased over #30 instrument. In the ProFile group, canal transportation was significantly increased after preparation with the #40 instrument at the 1- and 2- mm levels. LightSpeed group showed better centering ability than ProFile group after preparation with the #40 instrument at the 1 and 2 mm levels. CONCLUSIONS: SS K-file, Profile, and LightSpeed showed differences in the degree of apical transportation depending on the size of the master apical file.

Langerhans Cell Histiocytosis with Central Diabetes Insipidus: A Case Report / 영남의대학술지

Central diabetes insipidus (DI) is a syndrome characterized by thirst, polydipsia and polyuria. Langerhans cell histiocytosis is one of the etiologies of DI. Recently we experienced a central DI associated with Langerhans cell histiocytosis. The 44 years old female patient complained right hip pain, polydipsia and polyuria. We carried out water deprivation test. After vasopressin injection, urine osmotic pressure was increased from 109 mOsmol/kg to 327 mOsmol/kg (300%). Brain MRI showed a thickened pituitary stalk and air bubble like lesions sized with 5cm, 7cm was shown on fifth L-spine and right hip bone at hip bone CT. CT guided biopsy revealed abnormal histiocytes proliferation and abundant lymphocytes. The final diagnosis was central DI associated with systemic Langerhans cell histiocytosis invading hip bone, L-spine and pituitary stalk. Desmopressin and etoposide chemotherapy were performed to the patient.