In vitro comparison of an Er:YAG laser-activated bleaching system with different light-activated bleaching systems for color change, surface roughness, and enamel bond strength

• Published in: Lasers in medical science 2018-12, Vol.33 (9), p.1913-1918
• Main Authors: Ergin, Esra, Ruya Yazici, A., Kalender, Bercem, Usumez, Aslihan, Ertan, Atilla, Gorucu, Jale, Sari, Tugrul
• Format: Article
• Language: English
• Subjects: Animals; Bleaching; Bond strength; Bonding strength; Cattle; Color; Cylinders; Data analysis; Data processing; Dental enamel; Dental Enamel - radiation effects; Dentistry; Enamel; Lasers; Lasers, Semiconductor; Lasers, Solid-State; Light; Light emitting diodes; Medicine; Medicine & Public Health; Optical Devices; Optics; Original Article; Photonics; Quantum Optics; Semiconductor lasers; Slabs; Surface Properties; Surface roughness; System effectiveness; Teeth; Tooth Bleaching; YAG lasers
• ISSN: 0268-8921; 1435-604X
• DOI: 10.1007/s10103-018-2555-0

To compare an Er:YAG laser-activated bleaching system with different light-activated in-office bleaching systems for color change, surface roughness, and post-bleaching enamel bond strength. 51 enamel slabs were prepared from the sound buccal enamel of extracted bovine teeth. The teeth were randomly divided into three groups according to different light-activated office bleaching systems ( n  = 17): diode laser (Epic, Biolase) (940 nm, 7 W, continuous mode), Er:YAG laser (LightWalker, Fotona) (2940 nm, 50 mJ, 10 Hz, 1000 μs), and LED (Radii Plus) (440–480 nm, 1500 mW/cm 2 ). All systems were used with their compatible bleaching agents according to manufacturers’ recommendations. The tooth color and surface roughness (Ra) were assessed at baseline and after bleaching using a spectrophotometer and a surface profilometer, respectively. The color change was determined by the CI E L * a * b * system (Δ E , Δ L *, Δ a *, Δ b *). Kruskal-Wallis test was used for color change whereas Kruskal-Wallis and Wilcoxon tests were used to analyze the roughness data. For shear bond strength test (SBS), composite cylinders were bonded on bleached enamel samples 14 days after bleaching procedures and stored in water (37 °C). Specimens were then debonded with a universal testing machine at 1 mm/min and data were analyzed by using Kruskal-Wallis test. All the tested bleaching systems were effective on color change (Δ E  > 3.3) and produced similar color change ( p  > 0.05). There were no significant differences among the Ra values of the groups neither at baseline nor after bleaching ( p  > 0.05). However, comparing the baseline and after bleaching Ra values, a significant increase was observed for all tested groups ( p