Effect of etching time and light source on the bond strength of metallic brackets to ceramic

Abstract

This study evaluated the bond strength of brackets to ceramic testing different etching times and light sources for photo-activation of the bonding agent. Cylinders of feldspathic ceramic were etched with 10% hydrofluoric acid for 20 or 60 s. After application of silane on the ceramic surface, metallic brackets were bonded to the cylinders using Transbond XT (3M Unitek). The specimens for each etching time were assigned to 4 groups (n=15), according to the light source: XL2500 halogen light, UltraLume 5 LED, AccuCure 3000 argon laser, and Apollo 95E plasma arc. Light-activation was carried out with total exposure times of 40, 40, 20 and 12 s, respectively. Shear strength testing was carried out after 24 h. The adhesive remnant index (ARI) was evaluated under magnification. Data were subjected to two-way ANOVA and Tukey's test (α=0.05). Specimens etched for 20 s presented significantly lower bond strength (p<0.05) compared with those etched for 60 s. No significant differences (p>0.05) were detected among the light sources. The ARI showed a predominance of scores 0 in all groups, with an increase in scores 1, 2 and 3 for the 60 s time. In conclusion, only the etching time had significant influence on the bond strength of brackets to ceramic.

Orthodontic bonding to porcelain: A systematic review

“…17,22 The results proved that the specimens that were etched for 60 seconds showed significantly higher bond strengths than the specimens etched for 20 seconds.…”

“…Three of the studies focused on showing the effect of laser irradiation on the adhesion of the bracket to porcelain and compared it to conventional techniques. [16][17][18] An and Sohn 19 and Akova et al 20 showed that the conventional technique of hydrofluoric acid (HFA) and silane, sandblasting and silane, orthophosphoric acid and silane, and hydrofluoric acid had higher bond strength than laser etch and silane. However, the bond strength of the laser group was significantly higher than the orthophosphoric acid, sandblasted, and control groups.…”

“…Goncalves et al 17 proved that there was no significant difference between the different light sources of XL2500 halogen light, UltraLume 5 LED, AccuCure 3000 argon laser, and Apollo 95E plasma arc in bond strength. Turkkahraman and Kucukesmen 18 determined the difference between using a LED light and a halogen light.…”

Influence of Thermal Cycles Number on Bond Strength of Metallic Brackets to Ceramic

“…The light-activation was carried out using light emitting diodes (LED; Radii Plus; SDI Limited, Bayswater, Victoria, Australia) with 4 exposures of 10 s (one in each side of the bracket), for a total exposure time of 40 s. When five brackets were bonded to the same ceramic cylinder, a punch-holed strip of black adhesive tape was used to avoid light exposure to adjacent brackets, restricting the polymerization light to the specimen being bonded (2,3,11). The irradiance of 1,100 mW/cm 2 , was measured with a power meter (Ophir Optronics Inc., Danvers, MA, USA) and a computer-controlled spectrometer (USB2000; Ocean Optics, Dunedin, FL, USA) with an energy density of 48 J/cm 2 .…”

“…The bonding of brackets to the tooth is commonly evaluated by tensile or shear bond strength tests. The shear bond strength test is the most used to evaluate the bonding of brackets to the tooth (2,3). It is most recommended because it reproduces the stresses caused at the bonding resin/enamel and bonding resin/bracket interfaces during alignment, leveling and sliding movements in the orthodontic treatment.…”