The laser has been used as an alternative effective method of etching enamel surface for direct bonding of orthodontic brackets instead of phosphoric acid. The aim of this study was to compare shear bond strength of orthodontic brackets following Er-
YAG versus Nd-YAG Laser etching. Eighty human extracted upper premolars were collected and divided randomly into two equal groups; the buccal enamel surface of the first group was etched by Er-YAG laser while the second group was etched by Nd-YAG laser. Each group was divided into two equal subgroups according to the bonding material type (chemical cure resin or light cure resin). The mechanical test has occurred by using a universal testing machine (Instron). The finding showed that no statistically significant differences in mean of shear bond strength between (Nd-YAG, Er-YAG) Laser etching group were found regardless of the bonding type.
Laser use and applications in dentistry has increased dramatically in the last
years. Laser etching of enamel may provide an alternative for conventional acid etching. The aim of this
study was to evaluate, under Scanning Electron Microscope(SEM),
enamel surface morphology after
laser irradiation with or without the addition of photoabsorber (black ink); with or without acid etching.
laser enamel etching produced surface
roughness that might be used for the infiltration and subsequent mechanical retention of resin.
