Tese
Influência do laser de diodo na resistência de união à dentina e da superfície irradiada na evaporação do solvente de sistemas adesivos
Fecha
2017-07-07Autor
Friedrich, Luciana Roggia
Institución
Resumen
This study aimed to evaluate, in vitro, the bond strength to dentin and the influence of
their radiated surface (glass and dentin) on the evaporation degree of solvent of
adhesive systems by the use of high power diode laser. It was performed in two
stages, which consisted in: a) evaluating the bond strength (μSBS) through the
microshear test. For this, 48 healthy third molars were selected, which were
sectioned longitudinally, obtaining dentin disks. The specimens were randomly
divided into 8 groups (n = 6) as a function of the adhesive system (Adper Scotchbond
Multi-Purpose, Adper Single Bond 2, Clearfill SE Bond, and Optibond All-in-one) and
no irradiation or irradiation with high power diode laser (experimental technique x
control technique). The diode laser was applied continuously, perpendicularly and at
a distance of 1 cm from the irradiated surface, at a power of 3 W for a time of 25
seconds. In the course, a cylindrical matrix of starch adhered to dentin, composite
resin restora were made, which were stored for 24 hours at 37°C, and then submitted
to the microshear test in the universal testing machine, using 1.0 mm/min speed until
failure occurs; b) to evaluate the influence of their radiation surface on the
evaporation degree of solvent (ED) by the gravimetric method. The groups were
distributed according to adhesive systems (Adper Single Bond 2 and Clearfil SE
Bond) and their radiation surface (glass and dentin). For the dentin surface, 12
human third molars had class I cavities made. For both evaluated surfaces, 10μL of
each of the tested products were dispensed and the weight loss was measured. For
each material, six monitoring series (n = 6) were taken. The ED and μSBS data were
submitted to variance analysis, t-student test and/or Tukey’s test ( = 5%). Based on
the values obtained from μSBS , the laser promoted higher μSBS values for the
conventional adhesives when compared to the self-etch agents, being superior to the
control technique for Adper Single Bond 2. In relation to the ED, the diode laser at a
power of 3 W from 15 s, caused greater evaporation of the solvents in the
conventional adhesive system when compared to the self-etch. In relation to their
radiation surface, in almost all the times used, the laser caused greater evaporation
of the solvents when their radiated surface was the glass. In this way, the diode laser
appears as a new method, being dependent on the characteristics inherent to each
adhesive system and their radiated surface.