The extent of luting agent remnants on titanium and zirconia abutment analogs after scaling

To quantify the cement remnants on titanium and zirconia abutment analogs after cement removal by resin and steel scalers.

Defined areas of titanium or zirconia cylindric samples were covered with thin cement rings of zinc oxide phosphate (ZOP), glass ionomer (GIC), carboxylate (CAB), zinc oxide-eugenol (ZOE), or zinc oxide-eugenol-free (ZOEF). The cements were mixed with liquid-to-powder ratios of 50%, 75%, 100%, and 150% of powder. After setting and aging by thermocycling, each specimen was scaled by a blinded, trained clinician. Standardized digital photos of the scaled areas were analyzed according to a four-point classification scheme for remnants, and the results were analyzed statistically.

The main effects of the independent variables "cement type," "abutment material," and "scaler" showed statistically significant differences for all variables. Such differences were also found with regard to the interactions of the variables "cement type" and "material" as well as for the type of cement and scaler. The extent of remnants after scaling differed significantly between titanium and zirconia. Steel scalers achieved statistically significantly better cleaning than resin scalers. The powder-to-liquid ratio of all luting agents significantly influenced the extent of cement surplus after scaling. ZOEF was the only type of cement that could be more successfully removed from titanium than from zirconia.

Nearly complete removal of ZOE could be achieved. This luting agent was not as sensitive to aberrant mixing ratios or to resin or steel scaling as the other types of cement. With the exception of ZOEF, zirconia surfaces were easier to clean. After removal of most of the remnant, some cements showed a barely visible thin greasy or powdery layer.