title: Evaluation of the genotoxicity and cytotoxicity of filling pastes used for pulp therapy on deciduous teeth using the micronucleus test on bone marrow from mice (Mus musculus).
abstract: Pulp therapy is the last resort for preserving deciduous teeth. However, the genotoxic and cytotoxic effects of many products used in this therapy are not well established. The aim of this study was to use the micronucleus test on bone marrow from mice to evaluate the genotoxic and cytotoxic effects of four filling pastes: zinc oxide, calcium hydroxide P.A., mineral trioxide aggregate and an iodoform paste (iodoform + camphorated + paramonochlorophenol + rifamycin + prednisolone). Male Swiss mice were divided into 4 groups of 10 animals, each exposed to one of the pastes, and were subdivided according to the dilutions tested: 1/10, 1/50, 1/500 and 1/1000 administered intraperitoneally (0.1ml/10g of weight). Cyclophosphamide was the positive control. The negative controls were dimethylsulfoxide and buffered saline solution. Five animals were killed 24h and five 48h after the treatment. The material was processed in accordance with Schmid (1976) and micronuclei were counted in 1000 polychromatic erythrocytes (PCE), under an optical microscope in a blinded test. Cytotoxicity was evaluated using the PCE/normochromatic erythrocyte (NCE) ratio in 200 erythrocytes. The micronucleus analysis results were evaluated using the conditional test for comparing proportions in situations of rare events. Analysis of variance and Tukey's test were used to evaluate the PCE/NCE ratio. There was significantly greater occurrence of micronuclei in the animals treated with iodoform paste at all the dilutions tested, at both sacrifice times. Greater occurrence of micronuclei was observed among the animals treated with zinc oxide and sacrificed 48h after the treatment, at the dilutions 1:50; 1:500 and 1:1000. Calcium hydroxide P.A. and mineral trioxide aggregate did not present any genotoxic or cytotoxic effects. The genotoxicity and cytotoxicity of zinc oxide and iodoform paste revealed here constitute an initial step towards their contraindication, but additional studies will be necessary in order to securely establish the risks involved in their use.
authors.affiliation: Departamento de Saúde 1, Universidade Estadual do Sudoeste da Bahia, Jequié, Bahia, Brasil, Grupo de Pesquisa ESPIA/UESB/CNPq, santosncn@gmail.com.
authors.forename: Nilton C N
authors.initials: NC
authors.lastname: Santos
authors.affiliation: Departamento de Saúde, Universidade Estadual de Feira de Santana, Feira de Santana, Bahia, Brasil and.
authors.forename: Maria E S P
authors.initials: ME
authors.lastname: Ramos
authors.affiliation: Departamento de Saúde, Universidade Estadual de Feira de Santana, Feira de Santana, Bahia, Brasil and.
authors.forename: Aline F B
authors.initials: AF
authors.lastname: Ramos
authors.affiliation: Departamento de Saúde, Universidade Estadual de Feira de Santana, Feira de Santana, Bahia, Brasil and.
authors.forename: Adriana B
authors.initials: AB
authors.lastname: Cerqueira
authors.affiliation: Laboratório de Genética Toxicológica, Departamento de Ciências Biológicas, Programa de Pós-Graduação em Biotecnologia, Universidade Estadual de Feira de Santana, Bahia, Brasil.
authors.forename: Eneida M M
authors.initials: EM
authors.lastname: Cerqueira
mesh_terms: D017607:Aluminum Compounds / Q000009:adverse effects / Q000627:therapeutic use / Q000633:toxicity; D000818:Animals; D001853:Bone Marrow / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D017610:Calcium Compounds / Q000009:adverse effects / Q000627:therapeutic use / Q000633:toxicity; D002126:Calcium Hydroxide / Q000009:adverse effects / Q000627:therapeutic use / Q000633:toxicity; D004247:DNA / Q000187:drug effects / Q000378:metabolism; D004249:DNA Damage; D004338:Drug Combinations; D006847:Hydrocarbons, Iodinated / Q000009:adverse effects / Q000627:therapeutic use / Q000633:toxicity; D008297:Male; D051379:Mice; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced*; D015162:Micronucleus Tests; D009824:Ointments / Q000009:adverse effects / Q000737:chemistry; D010087:Oxides / Q000009:adverse effects / Q000627:therapeutic use / Q000633:toxicity; D012387:Root Canal Filling Materials / Q000009:adverse effects* / Q000627:therapeutic use / Q000633:toxicity; D017640:Silicates / Q000009:adverse effects / Q000627:therapeutic use / Q000633:toxicity; D014094:Tooth, Deciduous / Q000187:drug effects*; D015034:Zinc Oxide / Q000009:adverse effects / Q000627:therapeutic use / Q000633:toxicity
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D006847:Hydrocarbons, Iodinated; D009824:Ointments; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D004247:DNA; C010473:iodoform; D002126:Calcium Hydroxide; D015034:Zinc Oxide