Use of lithium disilicate implant abutment in the aesthetic region: a case report

Objectives. Esthetic properties of a prosthetic restoration depend on many factors, and core and veneering materials are crucial ones. Lithium disilicate as all-ceramic material combines good mechanical properties to excellent aesthetic results, and compared to other glass-ceramics it shows very good performance. Aim of this work was to present a case report on the use of lithium disilicate abutment and crown for replacing an upper central incisor. Case presentation. The patient T.G. presented at the Dental Clinic, University of Ferrara with mobility of the left upper central incisor as chief complaint. The clinical and radiographic evaluation showed clinical attachment loss, bone loss and tooth mobility (Fig.1). An implant (SPI Element, Thommen Medical) was inserted in post-extraction socket in the same surgical time (Fig.2). A resin-bonded prosthesis was used as interim provisional. After 3 months a roll flap was performed and a screw provisional was realized for tissue conditioning (Figg.3-4). After maturation of soft tissue, an impression was taken and two abutments were realized using different material: a) a titanium abutment supporting a traditional porcelain-fused-on-metal (PFM) crown and b) a lithium disilicate abutment cemented on a titanium base supporting a lithium disilicate crown (LD). The latter was realized by waxing the abutment directly on the titanium base and then pressing it (IPS e.max Press, Ivoclar Vivadent, Fig.5). The ceramic abutment was cemented on the titanium base using luting composite (Multilink implant, Ivoclar Vivadent, Fig.6). The two prosthetic solutions were put in place and qualitatively evaluated by transillumination. Results. Figures 7-12 show the different effect of transillumination on PFM and LD crowns. Interestingly, the disilicate crown appears as the controlateral central incisor (Fig.13). In other words, the light transmission through LD appears to be the same as the natural tooth. The LD crown was chosen to be luted on the abutment using luting composite (Multilink, Ivoclar Vivadent). The follow-up at 30 months showed the stability of tissues and the maintenance of esthetic result (Fig.14). Conclusions. Lithium disilicate can be used as material for implant abutment in selected cases where esthetic demands are strict. Because no data on biomechanical outcome of such a solution are available, in vitro studies evaluating mechanical behavior and in vivo long term follow-ups are needed to validate routine use.