Comparative evaluation of retention of lithium disilicate crowns with four different cementation systems- An in-vitro Study

AIM OF THE STUDY: This in vitro study was performed to compare the retention of pressable lithium disilicate crowns cemented with four different cementation systems.METHODS: Eighty single rooted maxillary 1st premolars were collected after excluding teeth with caries and/or previous restorations. Preparation of the samples was standardized by using a diamond bur mounted onto a surveyor. An anatomic crown was waxed on each tooth and then hot pressed using lithium disilicate ceramic (IPS e.max PRESS, IvoclarVivadent). The samples were randomly divided into 4 groups (n = 20) according to different cementation systems. Each group sample was subjected to a seating force of 50N using universal testing machine. Each upper block was pulled along the path of insertion of the crown with a crosshead speed of 1mm/min.RESULTS: Self adhesive resin cement showed the maximum tensile strength among all adhesive luting cements (2.65 MPa). Self etch resin cement group showed mean tensile strength of (1.78 MPa) that was marginally less than total etch resin cement (1.86 MPa). Glass ionomer cement exhibited least tensile strength (1.41 MPa) compared to the other three luting cements.CONCLUSION: Within the limitations of this in vitro study, it was concluded that lithium disilicate full coverage crowns cemented with self adhesive resin cement showed higher bond strength followed by total etch resin cement, self etch resin cement and glass ionomer cement.