الفهرس 
DeclarationOnly 14 pages are availabe for public view
 |  | from | 220 |  |  |
| | | from | 220 | | |
Abstract
Aim: to evaluate the clinical performance of two finish line designs (feather edge and rounded shoulder) in relation with two occlusal designs (flat and planar) in endodontically treated teeth restored with monolithic zirconia crowns.
Methodology: Sixty-six full-coverage monolithic zirconia crowns were constructed for posterior enododntically treated teeth. The patients were divided into three groups based on the preparation design: the control group (PS) had a planar occlusal scheme with a rounded shoulder finishline; the intervention 1 group (FF) had a flat occlusal scheme with a feather-edge finishline; and the intervention 2 group (FS) had a flat occlusal scheme with a rounded shoulder finishline. The crowns were designed on exocad software and milled with a 5 axes machine. Following cementation, clinical performance in terms of marginal daptation, marginal discoloration, fracture, and secondary caries was evaluated the modified United States Public Health Service (USPHS) criteria. The gingival index score system was used to evaluate the gingival response. The scores were recorded immediately following cementation and at three subsequent follow-up visits every three months for one year.
Results: In terms of marginal adaptations, the control group (PS) demonstrated the best marginal adaptation scores during follow-up visits, followed by intervention 2 (FS), and lastly, intervention 1 (FF), which earned mostly bravo scores. At the third follow-up, the intervention 1 (FF) group reported the majority of gingival responses among all groups. There was no significant difference between the groups in terms of marginal discolouration, fracture, or secondary caries at any of the follow-up visits. Each group received a perfect Alpha score of 100 percent on all three follow-up assessments.
Conclusions: In this one-year randomized clinical trial, all evaluated preparation schemes and corresponding crowns were clinically successful. The clinical performance of monolithic zirconia crowns of the novel preparation design (FF) in terms of marginal adaption, fracture, secondary caries, and marginal discoloration was successful.