Avaliação da irradiação do Nd:YAG laser sobre esmalte dental, associada ou não a um fotoabsorvedor, na redução da desmineralização por cárie artificial
Carregando...
Arquivos
Data
2018-12-19
Autores
Silva, Mateus Rodrigues [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi avaliar a eficácia de diferentes parâmetros de energia do Nd:YAG laser, associados ou não a um fotoabsorvedor na redução da desmineralização por cárie artificial, sobre a superfície de esmalte dental. De coroas de incisivos bovinos foram obtidos 80 espécimes circulares com 6 mm de diâmetro e 2 mm de altura (1 mm de esmalte e 1 mm de dentina), o esmalte foi polido com lixas de carbeto de silício. Em cada espécime foi delimitada uma metade na qual o esmalte ficou exposto. As amostras foram avaliadas em Microdurômetro e FTIR para verificação inicial, e distribuídas de forma aleatória em oito grupos (n=10), que receberam os seguintes tratamentos de superfície sobre o esmalte: G1 (controle negativo): não recebeu tratamento de superfície; G2 (controle positivo): aplicação tópica de fluorfosfato acidulado 1,23% gel por 4 min; G3 (Nd:YAG 60 mJ / pulso, 10Hz, 48 J/cm2, não contato); G4 (fotoabsorvedor + Nd:YAG 60 mJ); G5 (Nd:YAG 80 mJ / pulso, 10Hz, 64 J/cm2, não contato); G6 (fotoabsorvedor + Nd:YAG 80 mJ); G7 (Nd:YAG 100 mJ / pulso, 10Hz, 80 J/cm2, não contato); G8 (fotoabsorvedor + Nd:YAG 100 mJ). Após os tratamentos as amostras foram submetidas ao ciclo de des-remineralização para indução artificial de cárie, sendo então avaliadas em Interferômetro de luz branca, Microdurômetro e FTIR. Os resultados de microdureza foram submetidos à Análise de variância (ANOVA) sob 2 fatores (laser e fotoabsorvedor); ao teste de Tukey e ao teste de Dunnett, com nível de significância de 5% (=0,05). Diferenças estatisticamente significantes foram obtidas no fator fotoabsorvedor individualmente e na interação entre os fatores laser e fotoabsorvedor. Houve menor porcentagem de perda de microdureza nos grupos com fotoabsorvedor comparados aos grupos sem fotoabsorvedor e no grupo G8 comparado aos demais grupos experimentais, o qual apresentou ainda média de microdureza semelhante ao grupo G2. Os dados do FTIR foram submetidos ao Teste T, com nível de significância de 5% (=0,05). Comparadas com G2 foram encontradas maiores concentrações de carbonato em G4, G6 e G8; de fosfato em G8; menor concentração de Amida I em G8 e maior relação Carbonato/Fosfato em G4 e G6. Os resultados de interferometria foram submetidos à ANOVA a três fatores de medidas repetidas, com nível de significância de 5% (=0,05). Houve diferenças estatisticamente significantes no fator fotoabsorvedor individualmente e no fator tempo. Concluiu-se que o emprego de fotoabsorvedor diminuiu a desmineralização, os parâmetros de Nd:YAG laser sem fotoabsorvedor foram menos efetivos que o flúor na prevenção da desmineralização, o parâmetro de 100 mJ do Nd:YAG laser com fotoabsorvedor foi tão efetivo quanto o flúor na redução da desmineralização e a aplicação do Nd:YAG laser, associado ou não ao fotoabsorvedor, não foi mais eficaz que o flúor na redução da desmineralização por cárie artificial.
The aim of this study was to evaluate the effectiveness of different energy parameters of the Nd:YAG laser, associated or not to a photoabsorber in the reduction of demineralization by artificial caries, on the surface of dental enamel. From the crowns of bovine incisors, 80 circular specimens with 6 mm diameter and 2 mm height (1 mm of enamel and 1 mm of dentin) were obtained, the enamel was polished with silicon carbide sandpapers. In each specimen surface was delimited a half in which the enamel was exposed. The samples were evaluated in Microdurometer and FTIR for initial verification, and randomly distributed in eight groups (n = 10), which received the following surface treatments on the enamel: G1 (negative control): no surface treatment; G2 (positive control): topical application of acidulated fluorophosphate 1.23% gel for 4 min; G3 (Nd:YAG 60 mJ / pulse, 10 Hz, 48 J / cm2 , non-contact); G4 (photoabsorber + Nd:YAG 60 mJ); G5 (Nd:YAG 80 mJ / pulse, 10 Hz, 64 J / cm2 , non-contact); G6 (photoabsorber + Nd:YAG 80 mJ); G7 (Nd: YAG 100 mJ / pulse, 10 Hz, 80 J / cm2 , non-contact); G8 (photoabsorber + Nd:YAG 100 mJ). After the treatments, the samples were submitted to the deremineralization cycle for artificial induction of caries, and were then evaluated in White Light Interferometer, Microdurometer and FTIR. The microhardness results were submitted to Analysis of Variance (ANOVA) under 2 factors (laser and photoabsorber); to the Tukey test and the Dunnett test, with a significance level of 5% ( = 0.05). Statistically significant differences were obtained in the photoabsorber factor individually and in the interaction between the laser and photoabsorber factors. There was a lower percentage of microhardness loss in the photoabsorber groups compared to the non-photoabsorber groups and in the G8 group compared to the other experimental groups, which also presented a microhardness average similar to the G2 group. The FTIR data were submitted to the T test, with a significance level of 5% ( = 0.05). Compared with G2, higher concentrations of carbonate were found in G4, G6 and G8; phosphate in G8; lower Amide I concentration at G8 and higher Carbonate / Phosphate ratio at G4 and G6. The interferometry results were submitted to ANOVA under three factors of repeated measures, with a significance level of 5% ( = 0.05). There were statistically significant differences in the photoabsorber factor individually and in the time factor. It was concluded that the use of photoabsorber decreased the demineralization, the non-photoabsorber Nd:YAG laser parameters were less effective than fluoride in the prevention of demineralization, the parameter of 100 mJ of the Nd:YAG laser with photoabsorber was as effective as fluoride in the reduction of demineralization and the application of Nd:YAG laser, associated or not to the photoabsorber, was no more effective than fluoride in the reduction of artificial caries demineralization.5% ( = 0.05).
The aim of this study was to evaluate the effectiveness of different energy parameters of the Nd:YAG laser, associated or not to a photoabsorber in the reduction of demineralization by artificial caries, on the surface of dental enamel. From the crowns of bovine incisors, 80 circular specimens with 6 mm diameter and 2 mm height (1 mm of enamel and 1 mm of dentin) were obtained, the enamel was polished with silicon carbide sandpapers. In each specimen surface was delimited a half in which the enamel was exposed. The samples were evaluated in Microdurometer and FTIR for initial verification, and randomly distributed in eight groups (n = 10), which received the following surface treatments on the enamel: G1 (negative control): no surface treatment; G2 (positive control): topical application of acidulated fluorophosphate 1.23% gel for 4 min; G3 (Nd:YAG 60 mJ / pulse, 10 Hz, 48 J / cm2 , non-contact); G4 (photoabsorber + Nd:YAG 60 mJ); G5 (Nd:YAG 80 mJ / pulse, 10 Hz, 64 J / cm2 , non-contact); G6 (photoabsorber + Nd:YAG 80 mJ); G7 (Nd: YAG 100 mJ / pulse, 10 Hz, 80 J / cm2 , non-contact); G8 (photoabsorber + Nd:YAG 100 mJ). After the treatments, the samples were submitted to the deremineralization cycle for artificial induction of caries, and were then evaluated in White Light Interferometer, Microdurometer and FTIR. The microhardness results were submitted to Analysis of Variance (ANOVA) under 2 factors (laser and photoabsorber); to the Tukey test and the Dunnett test, with a significance level of 5% ( = 0.05). Statistically significant differences were obtained in the photoabsorber factor individually and in the interaction between the laser and photoabsorber factors. There was a lower percentage of microhardness loss in the photoabsorber groups compared to the non-photoabsorber groups and in the G8 group compared to the other experimental groups, which also presented a microhardness average similar to the G2 group. The FTIR data were submitted to the T test, with a significance level of 5% ( = 0.05). Compared with G2, higher concentrations of carbonate were found in G4, G6 and G8; phosphate in G8; lower Amide I concentration at G8 and higher Carbonate / Phosphate ratio at G4 and G6. The interferometry results were submitted to ANOVA under three factors of repeated measures, with a significance level of 5% ( = 0.05). There were statistically significant differences in the photoabsorber factor individually and in the time factor. It was concluded that the use of photoabsorber decreased the demineralization, the non-photoabsorber Nd:YAG laser parameters were less effective than fluoride in the prevention of demineralization, the parameter of 100 mJ of the Nd:YAG laser with photoabsorber was as effective as fluoride in the reduction of demineralization and the application of Nd:YAG laser, associated or not to the photoabsorber, was no more effective than fluoride in the reduction of artificial caries demineralization.5% ( = 0.05).
Descrição
Palavras-chave
Esmalte, Desmineralização, Cárie, Laser, Fotoabsorvedor, Enamel, Demineralization, Caries, Laser, Photoabsorber