title: L929 cell response to root perforation repair cements: an in vitro cytotoxicity assay.
abstract: This study compared the cytotoxicity of an experimental epoxy-resin and calcium hydroxide-based cement (MBPc), gray mineral trioxide aggregate (MTA) and white mineral trioxide aggregate (WMTA) using the agar overlay method with neutral red dye. L929 cells were seeded into 6-well culture plates where 48-h set test materials were placed on the agar overlay, in triplicate. Teflon and natural rubber served as negative and positive controls. After an incubation period of 24 h at 37 degrees C in a humidified atmosphere of 5% CO2 in air, a discolored area around the samples and the positive controls could be observed and measured per quadrant. The mean values were compared and converted into grades to classify the results according to the table of cytotoxicity grades according to the Standard Operating Procedures (SOP) of the Oswaldo Cruz Foundation, Brazil. The nonviable cell areas and the morphological changes in the cells were observed with an inverted microscope. The results showed grade 1 (slight) for the two types of MTA (p>0.05) and grade 2 (mild) for the MBPc (p<0.001). All samples met the requirements of the test as none of the cultures showed reactivity higher than grade 2.
authors.affiliation: Subdivisão de Ensino e Pesquisa, Santos Dumont Brazilian Air Force Dental Clinic, Praça Marechal Ancora, 77, Rio de Janeiro 20021-200, RJ, Brazil. rosanabelchior@uol.com.br
authors.forename: Rosana Belchior
authors.initials: RB
authors.lastname: Miranda
authors.forename: Sandra Rivera
authors.initials: SR
authors.lastname: Fidel
authors.forename: Maria Aparecida Affonso
authors.initials: MA
authors.lastname: Boller
mesh_terms: D017607:Aluminum Compounds / Q000633:toxicity; D000818:Animals; D017610:Calcium Compounds / Q000633:toxicity; D002126:Calcium Hydroxide / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D003762:Dental Instruments / Q000009:adverse effects; D004338:Drug Combinations; D004853:Epoxy Resins / Q000633:toxicity; D005347:Fibroblasts / Q000187:drug effects*; D007739:L Cells; D051379:Mice; D010087:Oxides / Q000633:toxicity; D019279:Resin Cements / Q000737:chemistry / Q000633:toxicity*; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000633:toxicity*; D018915:Root Canal Preparation / Q000009:adverse effects / Q000295:instrumentation; D017640:Silicates / Q000633:toxicity; D018677:Tooth Injuries / Q000628:therapy*; D014092:Tooth Root / Q000293:injuries*
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D004853:Epoxy Resins; D010087:Oxides; D019279:Resin Cements; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D002126:Calcium Hydroxide