Purpose: The purpose of this study was to evaluate the effect of crowns with different emergence profiles on marginal plaque formation. Materials and Methods: Seven crown preparations were performed on premolar teeth in six patients. Four titanium crowns for each tooth—with different marginal emergence angles—were manufactured according to the Procera technique. The three experimental crowns and the final permanent tooth were cemented with phosphate permanent cement. Plaque samples were collected from the marginal area after 1 week with normal oral hygiene, and again after refraining from oral hygiene for 2 days. The contralateral tooth served as a control. The quantity and quality of plaque were registered. The restoration was removed, the next crown version cemented, and the protocol repeated. Results: All experimental crowns, irrespective of emergence profile, showed a significantly lower (P = .01) plaque quantity than controls. No intraindividual differences were found regarding the accumulation of mutans streptococci at the different experimental emergence profiles. No differences in quality between experimental and control sides were found. Conclusion: Within the limitations of this study, it was found that titanium crowns with emergence profiles of up to 40 degrees formed less plaque than healthy controls. There was no higher accumulation of mutans streptococci in relation to increasing emergence profiles. Int J Prosthodont 2002;15:457–460.