Efeito da associação de fosfato de cálcio, laser Nd:YAG e adesivo na permeabilidade dentinária e na resistência de união
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Data
2017-12-11
Autores
Benitez Sellan, Pablo Lenin
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi avaliar in vitro o efeito do tratamento com a associação de fosfato de cálcio, laser de Nd:YAG e sistema adesivo na permeabilidade dentinária e na resistência de união. Foram utilizados 60 discos de dentina com aproximadamente 6 mm de diâmetro e 1,5 mm de altura, obtidos de molares humanos hígidos. Os espécimes foram divididos em dois grupos de acordo com a prévia aplicação ou não do fosfato de cálcio (TeethMate Desensitizer - Kuraray Notitake Dental Inc.). Cada grupo foi dividido em três subgrupos conforme o tratamento realizado (n=10): A- Adesivo (Single Bond Universal - 3M-ESPE), AL- Adesivo + Laser (Nd: YAG 60 mJ) , LAL- Laser + Adesivo + Laser. A permeabilidade foi mensurada em três momentos: com smear layer presente (inicial), após a abertura dos túbulos (máxima) e depois do tratamento (final). O percentual da permeabilidade inicial e final foi calculada em relação a permeabilidade máxima. Após a fotopolimerização do adesivo foi aplicado uma camada de 3 mm com a resina composta Filtek Z350 XT (3M-ESPE) com técnica incremental. Os espécimes foram submetidos a 5000 ciclos térmicos e 120.000 ciclos mecânicos, e posteriormente foi utilizado o teste de microtração. Adicionalmente foram observados em microscopia eletrônica de varredura (MEV) e microscopia confocal de varredura a laser (MCVL). Os grupos foram analisados pelo teste da analise de variância (ANOVA), teste t pareado e teste Tukey, adotando o nível de significância de 5%. Não foram observadas diferenças significativas entre os grupos na permeabilidade inicial (p=0,48) e após o tratamento (p=0,70). O percentual de permeabilidade após o tratamento foram (A: 42,11; AL: 39,09; LAL: 35,78; FA: 40,38; FAL: 34,23; FLAL: 30,25). O teste t pareado mostrou que o tratamento LAL promoveu uma redução significativa da permeabilidade em relação à inicial, tendo o fosfato de cálcio sido (p=30,25) ou não aplicado (p=35,78). Os tratamentos tiveram diferenças significativas na resistência de união, foi observado que os grupos FAL(31,53MPa), FLAL(31,37MPa) e AL(29,72MPa) apresentaram as maiores médias, que diferiram estatisticamente dos grupos restaurados só com Adesivo. Os demais grupos não apresentaram diferenças significantes (A: 24,34MPa; FA: 26,40MPa; LAL: 29,68MPa). Podemos concluir que o laser Nd:YAG aplicado antes e depois do sistema adesivo (Com e sem Fosfato de Cálcio), influenciou na redução da permeabilidade dentinária e os diferentes tratamentos na dentina influenciam significativamente a resistência de união entre a dentina e a resina, os grupos FAL, FLAL e AL apresentaram os melhores resultados. A correlação entre os parâmetros não teve influencia.
The objective of this study was to evaluate in vitro effect the association of calcium phosphate, Nd:YAG laser and adhesive system on dentin permeability and bond strength. Sixty dentin discs, approximately 6 mm in diameter and 1,5 mm high, were obtained from healthy human molars. The specimens were divided into two groups according to the prior application of calcium phosphate (TeethMate Desensitizer - Kuraray Noritake Dental Inc.). Each group was divided into three subgroups according to the treatment performed: A-Adhesive (Single Bond Universal - 3M-ESPE), AL- Adhesive + Laser (Nd: YAG 60 mJ) and LAL- Laser + Adhesive + Laser. The dentin permeability was measured in three moments: with smear layer present (initial), after opened tubules (maximum) and after treatment (final). The percentage of the initial and final permeability was calculated in relation to the maximum permeability. After adhesive photopolymerization, was applied the composite resin Filtek Z350 XT (3M-ESPE) with incremental technique. The specimens were cycled to 5000 thermal cycles and 120,000 mechanical cycles, and microtensile bond strength test was applied. Additionally they were observed in scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The groups were analyzed by ANOVA, paired t test and Tukey test (5%). No significant differences were observed between the groups on initial permeability (p=0.48) and after treatment (p=0.70). Permeability percentage after treatment was (A: 42.11, AL: 39.09, LAL: 35.78, FA: 40.38, FAL: 34.23, FLAL: 30.25). The paired t-test showed that LAL treatment promoted a significant reduction of the permeability in relation to the initial one, with calcium phosphate (p=30.25) or not applied (p=35.78). The treatments had significant differences in bond strength; FAL (31,53 MPa), FLAL (31,37 MPa) and AL (29,72 MPa) groups presented the highest averages, which differed statistically from the groups restored with only Adhesive. The other groups did not present statistically significant differences (A: 24.34 MPa, AF: 26.40 MPa, LAL: 29.68 MPa). It can be concluded that when the Nd:YAG laser was applied before and after the adhesive system (with and without Calcium Phosphate), it influenced the reduction of dentin permeability and the different treatments in dentin significantly influenced the bond strength between dentin and resin , the groups AL, LAL with application of Phosphate and AL without the use of Phosphate showed the best results. The correlation between the parameters had no influence.
The objective of this study was to evaluate in vitro effect the association of calcium phosphate, Nd:YAG laser and adhesive system on dentin permeability and bond strength. Sixty dentin discs, approximately 6 mm in diameter and 1,5 mm high, were obtained from healthy human molars. The specimens were divided into two groups according to the prior application of calcium phosphate (TeethMate Desensitizer - Kuraray Noritake Dental Inc.). Each group was divided into three subgroups according to the treatment performed: A-Adhesive (Single Bond Universal - 3M-ESPE), AL- Adhesive + Laser (Nd: YAG 60 mJ) and LAL- Laser + Adhesive + Laser. The dentin permeability was measured in three moments: with smear layer present (initial), after opened tubules (maximum) and after treatment (final). The percentage of the initial and final permeability was calculated in relation to the maximum permeability. After adhesive photopolymerization, was applied the composite resin Filtek Z350 XT (3M-ESPE) with incremental technique. The specimens were cycled to 5000 thermal cycles and 120,000 mechanical cycles, and microtensile bond strength test was applied. Additionally they were observed in scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The groups were analyzed by ANOVA, paired t test and Tukey test (5%). No significant differences were observed between the groups on initial permeability (p=0.48) and after treatment (p=0.70). Permeability percentage after treatment was (A: 42.11, AL: 39.09, LAL: 35.78, FA: 40.38, FAL: 34.23, FLAL: 30.25). The paired t-test showed that LAL treatment promoted a significant reduction of the permeability in relation to the initial one, with calcium phosphate (p=30.25) or not applied (p=35.78). The treatments had significant differences in bond strength; FAL (31,53 MPa), FLAL (31,37 MPa) and AL (29,72 MPa) groups presented the highest averages, which differed statistically from the groups restored with only Adhesive. The other groups did not present statistically significant differences (A: 24.34 MPa, AF: 26.40 MPa, LAL: 29.68 MPa). It can be concluded that when the Nd:YAG laser was applied before and after the adhesive system (with and without Calcium Phosphate), it influenced the reduction of dentin permeability and the different treatments in dentin significantly influenced the bond strength between dentin and resin , the groups AL, LAL with application of Phosphate and AL without the use of Phosphate showed the best results. The correlation between the parameters had no influence.
Descrição
Palavras-chave
Permeabilidade da dentina, Fosfato de cálcio, Laser de Nd:YAG, Resistencia de união, Dentin permeability, Calcium phosphate, Nd:YAG Laser, Bond Strenght