RESUMEN
INTRODUCTION: The aim of the present study was to evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis, and karyorrhexis) in exfoliated buccal mucosa cells from adults after fixed orthodontic therapy. MATERIAL AND METHODS: A total of 23 healthy adults (10 men and 13 women) undergoing orthodontic therapy were included in this setting. RESULTS: The results pointed out no significant statistically differences (P >0.05) of micronucleated oral mucosa cells. In the same way, orthodontic therapy was not able to increase other nuclear alterations closely related to cytotoxicity such as karyorrhexis, pyknosis and karyolysis (P >0.05). CONCLUSION: In summary, these data indicate that orthodontic therapy may not be a factor that induces chromosomal damage, nor it is able to promote cytotoxicity. Since DNA damage and cellular death are important events during carcinogenic processes, especially in early phases, this study represents a correct evaluation with respect to real health risks induced by orthodontic devices.
Asunto(s)
Daño del ADN , Mucosa Bucal/efectos de los fármacos , Aparatos Ortodóncicos/efectos adversos , Adolescente , Adulto , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Aleaciones de Cromo/toxicidad , Femenino , Humanos , Cariometría , Masculino , Pruebas de Micronúcleos , Mucosa Bucal/citología , Níquel/toxicidad , Acero Inoxidable/toxicidad , Estadísticas no Paramétricas , Titanio/toxicidad , Adulto JovenRESUMEN
UNLABELLED: Cell culture system has been used to evaluate alloy cytotoxicity under different environments, testing the extracts, but the effect of temperature variation on the cytotoxicity of dental alloys has not been analyzed. OBJECTIVE: The aim of the present study was to investigate if temperature variation could affect dental alloy cytotoxicity, testing alloy extracts in an epithelial cell culture system. MATERIAL AND METHODS: Discs of Ni-Cr, Co-Cr-Mo, Ni-Cr-Ti, Ti-6Al-4V and commercially pure titanium (cp Ti) were cast by arc melting, under argon atmosphere, injected by vacuum-pressure. Discs were immersed in artificial saliva and subjected to different temperatures: 37 degrees C and thermocycling (37 degrees C/5 degrees C/37 degrees C/55 degrees C/37 degrees C). After thermocycling, extracts were put in a subconfluent culture during 6 h, and the number of cells and their viability were used to evaluate cytotoxicity in these temperatures. For each alloy, data from temperature conditions were compared by Student's t-test (alpha=0.05). RESULTS: The cytotoxicity tests with alloy/metal extracts showed that Ni-Cr, Co-Cr-Mo, Ti-6Al-4V and cp Ti extracts (p>0.05) did not affect cell number or cell viability, while Ni-Cr-Ti (p<0.05) extract decreased cell number and viability when the alloy was subjected to thermocycling. CONCLUSION: Within the limitations of the present study, the Ni-Cr-Ti alloy had cell number and viability decreased when subjected to temperature variation, while the other alloys/metal extracts did not show these results.
Asunto(s)
Aleaciones Dentales/toxicidad , Revestimiento para Colado Dental/toxicidad , Materiales Dentales/toxicidad , Titanio/toxicidad , Aleaciones/química , Aleaciones/toxicidad , Óxido de Aluminio/química , Materiales Biocompatibles/química , Materiales Biocompatibles/toxicidad , Compuestos Inorgánicos de Carbono/química , Recuento de Células , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Aleaciones de Cromo/química , Aleaciones de Cromo/toxicidad , Aleaciones Dentales/química , Revestimiento para Colado Dental/química , Técnica de Colado Dental , Grabado Dental , Materiales Dentales/química , Pulido Dental/métodos , Diamante/química , Humanos , Ensayo de Materiales , Saliva Artificial/química , Compuestos de Silicona/química , Dióxido de Silicio/química , Temperatura , Titanio/químicaRESUMEN
Cell culture system has been used to evaluate alloy cytotoxicity under different environments, testing the extracts, but the effect of temperature variation on the cytotoxicity of dental alloys has not been analyzed. OBJECTIVE: The aim of the present study was to investigate if temperature variation could affect dental alloy cytotoxicity, testing alloy extracts in an epithelial cell culture system. MATERIAL AND METHODS: Discs of Ni-Cr, Co-Cr-Mo, Ni-Cr-Ti, Ti-6Al-4V and commercially pure titanium (cp Ti) were cast by arc melting, under argon atmosphere, injected by vacuum-pressure. Discs were immersed in artificial saliva and subjected to different temperatures: 37ºC and thermocycling (37ºC/5ºC/37ºC/55ºC/37ºC). After thermocycling, extracts were put in a subconfluent culture during 6 h, and the number of cells and their viability were used to evaluate cytotoxicity in these temperatures. For each alloy, data from temperature conditions were compared by Student's t-test (α=0.05). RESULTS: The cytotoxicity tests with alloy/metal extracts showed that Ni-Cr, Co-Cr-Mo, Ti-6Al-4V and cp Ti extracts (p>0.05) did not affect cell number or cell viability, while Ni-Cr-Ti (p<0.05) extract decreased cell number and viability when the alloy was subjected to thermocycling. CONCLUSION: Within the limitations of the present study, the Ni-Cr-Ti alloy had cell number and viability decreased when subjected to temperature variation, while the other alloys/metal extracts did not show these results.