Influence of Irradiance and Exposure Times on the Mechanical and Adhesive Properties of Universal Adhesives with Dentin.

Autor: Cardenas A; Andres Felipe Millan Cardenas, DDS, Ms, PhD, professor, Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil., Siqueira F; Fabiana Suelen Figuerêdo de Siqueira, DDS, Ms, PhD, professor, Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil., Nuñez A; Alejandra Nuñez, DDS, Ms, PhD student, Department of Restorative Dentistry, Ponta Grossa State University, Ponta Grossa, Paraná, Brazil, and Professor, Department of Restorative Dentistry and Biomaterials, San Francisco de Quito University, Quito, Ecuador., Nonato RF; Rammon de Faria Nonato, DDS, Ms student, Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil., Cavalcanti K; Karoline Guará Brusaca Almeida Cavalcanti, DDS, Ms, PhD student, Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil., Soares CJ; Carlos José Soares, DDS, Ms, PhD, professor, Departament of Postgraduate Program in Dentistry, CEUMA University, São Luis, MA, Brazil, and Dental School, Department of Operative Dentistry and Dental Materials, Federal University of Uberlândia, Uberlândia, MG, Brazil., Reis A; Alessandra Reis, DDS, PhD, professor, Department of Restorative Dentistry, Ponta Grossa State University, Ponta Grossa, PR, Brazil., Loguercio AD; Alessandro D. Loguercio, DDS, Ms, PhD, professor, Department of Restorative Dentistry, Ponta Grossa State University, Ponta Grossa, PR, Brazil.
Jazyk: angličtina
Zdroj: Operative dentistry [Oper Dent] 2022 Jul 01; Vol. 47 (4), pp. 412-424.
DOI: 10.2341/21-042-L
Abstrakt: Objectives: This study evaluated the influence of irradiance/exposure time on the Knoop hardness (KHN) and polymer cross-linking density (PCLD), as well as microtensile bond strength (μTBS), nanoleakage (NL), and in situ degree of conversion (DC) of universal adhesives.
Methods and Materials: Two universal adhesive systems, Clearfil Universal Bond Quick (CUQ) and Scotchbond Universal Adhesive (SBU), were light-cured using various irradiance/exposure times: 1400 mW/cm2 for 5 s (1400*5); 1400 mW/cm2 for 10 s (1400*10); 3200 mW/cm2 for 5 s (3200*5); and 3200 mW/cm2 for 10 s (3200*10). Adhesive disks from each group were used to measure PCLD by KHN. One hundred and twenty-eight human molars were randomly assigned to 16 groups according to the following variables: adhesive system vs adhesive strategies vs radiance/exposure times. After restoration, specimens were sectioned into resin-dentin sticks and tested for μTBS, NL, and DC. The data from PCLD (%), KHN, μTBS (MPa), NL (%), and DC (%) data were subjected to ANOVA and Tukey's test (α=0.05).
Results: Significant reductions in KHN, μTBS, and DC (p=0.00001) values and an increase in NL and PCLD (p=0.00001) values were observed for 3200*10 when compared with other groups. Higher KHN, μTBS, and DC (p=0.000001) values were observed for 3200*5 in comparison with the other groups. The 1400*5 (7 J/cm2) and 1400*10 (14 J/cm2) groups showed intermediate values (p=0.000001).
Conclusion: Although similar results in terms of hardness, polymer cross-linking density and nanoleakage were observed when 5 seconds at 3200 mW/cm2 and 10 seconds at 1400 mW/cm2 groups were compared, the use of higher irradiance (3200 mW/cm2) for only 5 seconds showed better results in terms of bond strength and degree of conversion for both universal adhesives to dentin. The prolonged exposure time (10 seconds) at the higher irradiance (3200 mW/cm2) showed the worst results.
(©Operative Dentistry, 2022.)
Databáze: MEDLINE
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