In vitro study of different methods in the removal of calcium hydroxide from root canals / 口腔疾病防治

Objective@#To compare the efficacy of different methods in the removal of calcium hydroxide from root canals and to provide a reference for clinical treatment. @*Methods@# A total of 160 extracted single-rooted mandibular premolars were instrumented up to ProTaper Universal F4. The roots were split longitudinally, and standardized groove and depression models were prepared and filled with calcium hydroxide. The samples were randomly divided into 4 groups (n=40) according to different irrigation methods: syringe needle irrigation, passive ultrasonic irrigation, XP-endo finisher (XPF) irrigation, and M3-Max irrigation. Each group was then divided into 2 subgroups (n=20) according to the irrigation protocol: NaOCl and NaOCl+EDTA. Photos of grooves and depressions were taken under a microscope after irrigation, and the residual calcium hydroxide was scored to compare the removal effects of different irritation methods and solutions.@*Results@#In the groove and depression model, when sodium hypochlorite is used as the irrigation fluid, ultrasound irrigation, XPF and M3-Max are better than syringe needle irrigation in removing calcium hydroxide (P < 0.05); when sodium hypochlorite combined with EDTA flushing, the effect of removing calcium hydroxide with ultrasound irrigation, XPF and M3-Max is better than that of syringe needle irrigation (P < 0.05); but there is no statistically significant difference between ultrasound, XPF and M3-Max (P > 0.05); when compared with the use of sodium hypochlorite, the combined use of EDTA irrigation could enhance the effect of ultrasonic irrigation, XPF and M3 Max on the removal of calcium hydroxide (P < 0.05), but there was no significant improvement in the syringe needle irrigation group (P > 0.05). @*Conclusion @#Sodium hypochlorite combined with EDTA can enhance the effect of ultrasonic irrigation, XPF and M3 Max on the removal of calcium hydroxide, and there is no significant difference among these approaches, which are more effective than syringe needle irrigation.

Pleuropulmonary blastoma in an infant.

Pleuropulmonary blastomas (PPB) are rare and highly aggressive tumors. Herein, we report an infantile case of type III PPB. A 9-mth-old boy presented to our unit with a history of cough and tachypnea for 2 days. Chest computed tomography revealed a mass in the left upper lobe, emphysema in the left upper lung, and mediastinum and heart shifted towards the right. The mass was removed completely by left upper lobectomy and histology confirmed diagnosis of type III PPB. The immature blastematous tissue was positive for vimentin while benign epithelium was positive for epithelial membrane antigen and cytokeratin. No lymph nodule metastasis was found in the 7 lymph nodules obtained from the hilum of the lung near the tumor. Currently, the patient is under close follow-up and is doing well.

Viral pathogens of acute lower respiratory tract infection in China.

OBJECTIVES: To document the viral etiology of acute lower respiratory tract infection (ALRIs) in Chinese children. SETTING: Children Hospital, Zhejiang University, China. STUDY DESIGN: Cross-sectional. PARTICIPANTS: 34885 children with ALRI between January 2001 to December 2006. METHODS: Nasopharyngeal aspirates were collected from all subjects. Respiratory syncytial virus (RSV), adenovirus (ADV), type 1 to 3 parainfluenza viruses (PIV), and type A and B influenza virus (Flu) were detected by direct immunofluorescence. RESULTS: Viruses were identified in 32.3% cases, including RSV (23.6%), PIV 3 (4.3%), Flu A (2.0%), ADV (1.7%), PIV I (0.6%), Flu B (0.2%) and PIV 2 (0.1%). RSV and PIV 3 predominated in younger children while Flu A and Flu B predominated in older children (P<0.001, respectively). PIV 1 was more prevalent in children aged 1 to 3 years. The peak frequency of RSV, PIV 3 and Flu A were in early spring, June to August, and August and September, respectively. Flu B had a peak in the winter and spring. Adenovirus infections occurred in all seasons with a relatively constant frequency. CONCLUSIONS: Viruses are an important cause of ALRIs in Chinese children constituting 1/3 of total cases. RSV is the most common pathogen.