Purpose: This study evaluated the marginal and internal adaptation of Proce
ra copings using different tooth preparations. The variations comprised 4 f
inish line forms, 3 occlusal forms, 3 occlusocervical undulation forms to t
he proximal finish line, and 3 proximal auxiliary retention forms. Material
s and Methods: One hundred twenty preparations were made and copings were f
abricated, cemented, embedded in an epoxy resin, sectioned, and measured at
14 sites. Results: The feather-edge finish line had the highest mean exter
nal marginal opening (135 +/- 79 mu m), compared with the chamfer finish li
ne (64 +/- 38 mu m), the 0.8-mm rounded shoulder (51 +/- 34 mu m), and the
0.5-mm rounded shoulder (68 +/- 56 mu m) All 3 forms of occlusal reduction
produced comparable internal adaptation at the axial wall. Specimens with n
ormal occlusal reduction had the best occlusal adaptation at the cusp tip b
ut not to a statistically different degree from the exaggerated form. Varia
tions in the vertical height of interproximal finish lines did not signific
antly affect marginal opening. However, proximal retentive features less th
an 2.5 mm wide and more than 0.5 mm deep cannot be accurately reproduced wi
th the present Procera scanner tip. Conclusion: Feather-edge finish-fine fo
rms, deep retentive grooves, and deep occlusal morphology are not well repr
oduced using this system, but all other finish-line forms and design variat
ions are accurately and clinically acceptably reproduced using this system.