[Cytotoxicity evaluation of three kinds of perforation repair materials on human periodontal ligament fibroblasts in vitro].

OBJECTIVE: To select three kinds of perforation repair materials, mineral trioxide aggregate (MTA), Z350, amalgam. And to evaluate the cytotoxicity of three kinds of perforation repair materials on human periodontal ligament fibroblasts (HPDLF) in vitro. METHODS: The proliferation of HPDLF to three perforation repair materials were examined by methyl thiazolyl tetrazolium (MTT) assay at 1, 3 and 5 days. The mRNA expression levels of bone-associated alkaline phosphatase (ALP) and osteocalcin (OC) were determined using a real-time quantitative polymerase chain reaction (PCR). RESULTS: MTA shew almost no inhibition to HPDLF, the expression of ALP mRNA and OC mRNA in the HPDLF cultured on MTA were higher. Z350 induced a slight inhibition to HPDLF, and the expression of ALP mRNA but there was no difference in the expression of OC mRNA. Cell proliferation was significantly impaired by amalgam with grade 3, and the expression of ALP mRNA and OC mRNA were significantly reduced. CONCLUSION: MTA have minimum cytotoxicity on HPDLF and can promote cell differentiation and regenerate of periodontal tissue. Z350 have lower cytotoxicity on HPDLF. Amalgam show highest cytotoxicity on HPDLF in the three materials and inhibit cells differentiation.

[Morphology and microleakage study of repairing subpulpal wall perforation with resinous inlay].

OBJECTIVE: The purpose of this study is to study the sealing ability and the furcal appearance of repairing subpulpal wall perforation with resinous inlay. METHODS: Fifty newly extracted human molars were randomly divided into three experiment groups (group A, group B, group C, 15 teeth each) and one control group (5 teeth). In experiment groups, perforations were made perpendicularly to the center of the pulp chamber floor. Perforations of group A and B were repaired with resinous inlay and sealed by AH Plus sealer and luting glass-ionomer, respectively. Perforations of group C were directly repaired using light-cure composite resin. Perforations were not made in five teeth of control group. The furcal appearances were evaluated under stereomicroscope after repairing. Microleakage was measured by glucose oxidase detection. RESULTS: The fineness rate of furcal appearances with resinous inlay repairing were 83.3%, while the fineness rate of furcal appearances with light-cure composite resin directly repairing were 46.7%. There were statistics difference between resinous inlay repairing and light-cure composite resin directly repairing (P<0.05). There were statistics difference among the daily microleakage of three experiment groups, group A