Two-part implant abutments with titanium and ceramic components: Surface modification affects retention forces-An in-vitro study

Objectives Two-part abutments consist of titanium base and ceramic coping. Their long-term success is largely determined by the mechanical stability. The aim of the present study was to investigate the retention forces of two-part implant abutments. The study included zirconia and lithium disilicate ceramics copings, with different surface treatments and resin-based luting agents. Material and Methods The analysis of retention forces was based on a total of 70 test specimens. Seven surface modifications and three resin-based luting agents were employed for the bonding of components in the seven groups (n = 70). All surfaces of titanium bases-except for a control-were pretreated with aluminum oxide blasting, either alone or in combination with surface activating primers. Surfaces of ceramic copings were also treated mechanically by sandblasting, either alone or with acid etching or different primers. All specimens underwent thermal aging (10(4) cycles, 5 degrees C/55 degrees C). The retention forces between the two parts were measured with a pull-off test. The results were analyzed by two-way ANOVA statistics. Fracture patterns were evaluated by light and scanning electron microscopy. Results No mechanical pretreatment of the titanium (group 2) base resulted in the lowest retention. The combination with Monobond plus leads to the highest pull-off forces for both ceramic materials. Conclusions Surface modifications and resin-based agents influence the retention of components of two-part abutments. Lithium disilicate ceramic copings reached comparable results of retention to the typically used zirconia copings.