Fixed partial restorations made of a new zirconia-reinforced lithium silicate material: a preliminary report

073KU ePOSTER CLINICAL RESEARCH – PROSTHETICS

Background: The use of lithium disilicate (LS2) glass-ceramics in prosthodontics is increasing since its introduction to dental practice. The hot-pressing of glass-ceramics creates a material with superior aesthetic properties when compared to the standard metal ceramic approach and similar hardness to the enamel of natural teeth.

Aim/Hypothesis: The aim of this study was to evaluate the performance of definitive, implant-supported or tooth-supported three-unit fixed dental prostheses made of zirconia-reinforced lithium silicate placed to restore premolars and molars in clinical cases of partial edentulism.

Materials and Methods: All patients received a three-unit fixed restoration made of monolithic, hot-pressed, zirconia-reinforced lithium silicate glass-ceramic. The restoration was cemented to two natural teeth or attached to two 3.5 or 4.5 mm diameter square threaded, grit-blasted and acid-etched integrated implants with a Morse-tapered connection. Peri-implant pocket depths, bone and soft tissue remodeling were recorded for two years at each follow-up visit. Esthetic, functional and biologic United States Public Health Services (USPHS) parameters modified by the FDI World Dental Federation study design were assessed yearly until the last follow-up appointment. The opposing dentitions were identified by type of restoration and supporting structures at the time of placement of the definitive restorations and at the yearly follow-up visits.

Results: A total of 100 patients were consecutively enrolled in the period between June 2016 and July 2017. One (2%) of the 50 implant-supported prostheses fractured after 21 months of function. NOe of the other prostheses failed, became loose or detached. No significant differences involving probing levels, bone and soft tissue remodeling were found between the research times. The most common issue occurred immediately after the placement of the prosthesis, when 3 patients (6%) from Group A and 4 patients (8%) from Group B asked for a modification of the tooth shade.

Conclusions and Clinical Implications: Implant-supported or tooth-supported three-unit fixed dental prostheses made of zirconia-reinforced lithium silicate can be used to successfully restore cases of posterior partial edentulism. The preliminary results of this study will be checked in an ongoing long-term follow-up.

Keywords: zirconia-reinforced lithium silicate, Conometric Concept