A standardized method for determination of crown margin fidelity

Previous research on crown margin fidelity is reviewed and methods of measurement are compared and scrutinized. A standardized method for the determination of crown margin fidelity is introduced. A biologically oriented rationale is presented for analysis of the measurement parameters. This system places a strong emphasis on measuring factors that impact upon accumulation of plaque and the microbiologic environment around crowns, ultimately affecting gingival health. Crown samples were cemented on master dies and were embedded for sectioning buccolingually and mesiodistally. Photographs of margins with plastic overlays indicating emergence profiles were used to determine vertical and horizontal marginal discrepancies. Three observers measured seven crown systems for the vertical and horizontal marginal discrepancies of each crown system. The interobserver variance was 10 microns for the horizontal and 9 microns for the vertical marginal discrepancy.