Clinical outcome of three-unit lithium-disilicate glass–ceramic fixed dental prostheses: Up to 8 years results

Objectives The purpose of this prospective study was to evaluate the clinical outcome of crown-retained fixed dental prostheses (FDPs) made from a lithium-disilicate glass-ceramic (IPS e.max Press, Ivoclar-Vivadent). Methods Thirty-six three-unit FDPs were placed in 28 patients. The FDPs replaced teeth in the anterior (16%) and posterior (84%) regions. All teeth were prepared following a standardized protocol. The size of the proximal connector of the FDPs was 12 mm2 (anterior) or 16 mm2 (posterior). FDPs were cemented either with glass-ionomer cement (n=19) or composite resin (n=17). The following parameters were evaluated at baseline, 6 months after cementation and then annually (at abutment and contralateral teeth): probing pocket depth, plaque index, bleeding on probing, and tooth vitality. Results Three FDPs were defined as drop-out. The mean observation period of the remaining 33 FDPs was 86 months (range: 67-98 months): two FDPs in two patients had to be replaced (6%) because of fractures. The 8-year survival rate according to Kaplan-Meier was 93%. In addition, chipping of the veneering material was found in two FDPs (6%). Two abutments (3%) of two restorations had to be treated endodontically; and two FDPs (6%) lost retention and had to be recemented. These complications did not affect the function of the involved restorations clinically. There were no significant differences between the periodontal parameters of the test and control teeth. Significance Short-span crown-retained three-unit FDPs made from lithium-disilicate glass-ceramic can be used clinically irrespective of an adhesive or conventional cementation.