Aim: The current research was conducted to analyze how the manufacturing procedure could affect the internal fit and marginal integrity of zirconia reinforced lithium silicate crowns.
Materials and methods: A typodont tooth for mandibular second molar was prepared in accordance with the criteria of all ceramic crown preparations. The prepared tooth was duplicated into 20 epoxy dies that was subsequently classified into 2 groups; Group 1 (n=10) milled zirconia reinforced lithium disilicate (ZLS) crowns and Group 2 (n=10) pressed ZLS crowns. Internal fit was recored by the replica approach while marginal fit was measured before and after cementation using stereomicroscope.
Results: Concerning marginal integrity, Pressed ZLS crowns recorded higher marginal gap than milled samples, before and after cementation, despite the absence of significant difference. Meanwhile, milled ZLS crowns recorded higher internal gap than that of pressed ZLS crowns, nevertheless, there was no siginificance (p=0.206).
Conclusions: Within the research's constraints, the manufacturing procedure for ZLS crowns had no influence on the crowns' marginal integrity or internal fit. The marginal and internal gaps created by the crowns in both groups were appropriate for clinical use.