Objective: This study investigated the effect of air-abrasion and erbium:yttrium-aluminum-gar net (Er:YAG) laser treatments on push-out bond strength (PBS) between hard relining material and metal housing of an overdenture attachment system. Materials and Methods: A total of 36 metal housings were randomly divided into 3 subgroups according to surface pretreatments (n=12): Control (no surface treatment; C), air-abrasion (A), and Er:YAG laser (L). Surface roughness (Ra) of specimens was determined using a profilometer. One additional specimen per group was evaluated by scanning electron microscopy (SEM). The hard relining material was bonded to metal housings, and a PBS test was performed using a universal testing machine. Data were statistically analyzed using 1-way analysis of variance (ANOVA), Tukey's honestly significant difference (HSD), and Tamhane's T2 tests (alpha =.05). Results: C and L groups showed the lowest and highest Ra values, respectively. The mean Ra of the A group was statistically different from the mean values of the C and L groups (P<.001). The L group showed higher PBS values than the C group (P<.05), whereas the A group exhibited statistically similar PBS values to both C and L groups (P>.05). Conclusion: Air-abrasion did not significantly increase the bond strength between the metal housing and hard relining material. Er:YAG laser irradiation noticeably improved the PBS but caused surface microcracks.
