Objective:To describe the procedures for management of the non-vital teeth with open apices using mineral trioxide aggregate(MTA). Methods:Six non-vital teeth with open apices in 6 patients aged 10～20 years old were treated with MTA. After a rubber dam was applied, a large access was made for debridement of the canal. Calcium hydroxide paste was placed in the canal for 1 week for disinfection. After the calcium hydroxide was rinsed from the canal at the subsequent appointment, a mixture of MTA powder with sterile water was carried into the canal with an amalgam carrier. The mix was condensed to the apical extent using pluggers to create a 3-4 mm apical plug. To ensure proper setting of MTA, a moist cotton pellet was placed in the canal over the material and the tooth was temporized, The remainder of the canal was obturated with gutta-percha and sealer or bonded composite resin was placed in the access cavity at next visit. Results:The patients had no abnormal symptoms and signs after apical plug. Radiograph demonstrated all open apices healing 6 months after obturation. Conclusion:MTA is effective and convenient in the management of non-vital teeth with open apices.

Objective: To compare the effects of engine-driven rotar y nickel-titanium(ni-ti) file and stainless steel hand K-file (ss-K-file) in posterior teeth’s root canal preparation. Methods: 118 root c anals of 45 cases were instrumented with ni-ti file (ProFile)by crow-down te chnique and 127 root canals of 49 cases were treated with ss-K-file by step- back technique respectively. The incidence of pain after preparation and the res ults of obturation were observed. Results:Total pain incidence i n ni-ti file preparation group and in ss-K-file group was 20.00% and 46.94% respectively (P

OBJECTIVETo investigate the expression types of protease-activated receptors(PAR) in human gingival fibroblasts(HGF) and the functions of PAR in periodontitis.

METHODSPrimary HGF were cultured.Reverse transcription PCR(RT-PCR) was used to detect the expression of PAR in HGF. Recombinant gingipain R (rRgp) was applied to HGF. The change of PAR expression on the cell surface was analyzed by real-time quantitative RT-PCR, and enzyme-linked immunosorbent assay (ELISA) was used to detect the change of the interleukin (IL)-6 production from HGF. The results of RT-PCR and ELISA were statistically analyzed using the two independent samples t-test of SPSS10.0 software.

RESULTSHGF expressed PAR-1 and PAR-3. The expression of PAR-1 and PAR-3 changed after two rRgp treatment with HGF cells. The relative expression of PAR-1 was decreased from 1.04 ± 0.31 to 0.67 ± 0.11 and 0.31 ± 0.11. The relative expression of PAR-3 was decreased from 1.01 ± 0.44 to 0.79 ± 0.13 and 0.44 ± 0.12(P < 0.05). The level of IL-6 was increased after rRgp treatment for 8 h. The control group was (18.77 ± 4.09) µg/L, the rRgp treatment groups were (179.36 ± 15.81) and (320.56 ± 26.19) µg/L respectively.

CONCLUSIONSHGF expressed PAR-1 and PAR-3 and were involved in periodontal inflammation.

Adhesins, Bacterial ; Cell Membrane ; Cysteine Endopeptidases ; Enzyme-Linked Immunosorbent Assay ; Fibroblasts ; Gingiva ; metabolism ; Humans ; Interleukin-6 ; Periodontitis ; metabolism ; Receptors, Proteinase-Activated ; biosynthesis