Marginal fit analysis of premachined and castable UCLA abutments.

This study evaluated the fit between implants and premachined and castable UCLA abutments. All plastic specimens were cast using the conventional technique in accordance with the manufacturer's instructions. Five specimens of each experimental group were measured for vertical and horizontal gaps by scanning electronic microscopy (Phillips XL 30 model, Holland). Gold UCLA (vertical gap: 2.15 microm, horizontal gap: 11.30 microm) and castable rotational UCLA (vertical gap: 14.91 microm, horizontal gap: 59.41 microm) groups showed the lowest and highest mean values, respectively (Neodent, Curitiba, Parana, Brazil). In general, the castable UCLA abutments showed poorer marginal fit than the premachined abutments.