Abstract: Objective To study the marginal microleakage of glass fiber post-and-cores and all-ceramic crowns by a one-step method of designing and fabricating simultaneously to provide a theoretical basis for clinical application of this method. Methods Twenty isolated teeth were collected and divided into the experimental group and the control group randomly. Teeth in the experimental group were prepared with post and all-ceramic crown abutment. Post-and-cores and all-ceramic crowns were designed by digital software simultaneously and were then fabricated. Teeth in the control group were prepared with all-ceramic crown abutment and crowns were then manufactured. All samples were subjected to temperature cycling test and methylene blue staining. After incisions, results of coronal microleakage were observed and measured under a stereo microscope. Results The crown dye of all samples penetrated into edges of all-ceramic crowns and tooth tissues, and adhered to surface of the adhesive at shoulders horizontally. In the experimental group, there was no obvious dye penetration at the edge of post-and-cores. Comparing measurement results of the marginal microleakage, there was no statistically significant difference between the experimental group and the control group (P>0.05). Conclusion It is shown that glass fiber post-and-cores and all-ceramic crowns by a one-step method of designing and fabricating simultaneously can meet clinical requirements for the edge suitability of all-ceramic crowns.

Key words: one-step method, glass fiber post-and-core, all-ceramic crown, microleakage