Longevity of Polymer-Infiltrated Ceramic Network and Zirconia-Reinforced Lithium Silicate Restorations: A Systematic Review and Meta-Analysis

Abstract

The purpose of this study was to systematically review the existing literature to assess the clinical survival and success of PICN and ZLS indirect restorations as the clinical evidence for them remains lacking. PubMed, SCOPUS, Embase, Cochrane Library, Web of Science, LILACs, and SciElo databases were searched from 1 January 2000 to 1 February 2021. Clinical trials and cohort studies published in English were included while case studies, case series, and in vitro studies were excluded. Results were analyzed qualitatively and a meta-analysis using a random effects model was performed. A strength of recommendation taxonomy (SORT) analysis was conducted and risk of bias (RoB) was assessed using the Newcastle–Ottawa scale and Cochrane RoB tools. An electronic search through the databases yielded 2454 articles, of which 825 remained after duplicate removal. Five studies investigating PICN and four investigating ZLS indirect restorations remained after assessing for eligibility. The overall survival rate of PICN over 1 year was 99.6% and 99.2% over 2 years. The overall survival rate of ZLS over 1 year was 99%. The main mode of failure for both materials was catastrophic fracture. One study had a high RoB, four had a moderate RoB, and four had a low RoB. Both materials demonstrated moderate strength of recommendation at a level 2 evidence for all studies based on SORT analysis. PICN and ZLS show promising short-term clinical performance as full and partial coverage indirect restorations, but longer follow-up studies are required to confirm their long-term performance.

Evaluation of Marginal/Internal Fit and Fracture Load of Monolithic Zirconia and Zirconia Lithium Silicate (ZLS) CAD/CAM Crown Systems

“…Currently, CAD/CAM techniques have found widespread application for all types of prostheses—fixed, partial, and completely removable, with different types of ceramic and polymer-based materials [ 10 , 15 , 16 , 86 ]. Future studies comparing the fit accuracy and fracture resistance of the latest monolithic translucent Zi (partially and fully stabilized zirconia), fully crystallized ZLS, and nano-ceramic materials with the monolithic Y-TZP, LDS, and ZLS pre-crystallized glass ceramic materials are required to test the efficacy of the new materials for different types of indirect fixed restorations.…”

“…Lithium disilicates have also been in wide use for making complete coverage crowns in dentistry [ 13 , 14 ], and the material can be either pressed or milled by CAD/CAM. Recently, a modified form of this material, zirconia-reinforced lithium silicate (ZLS) was introduced [ 6 , 15 ]. The ZLS material has the lithium silicate crystals in a glassy matrix in combination with 8–12% zirconia crystals, which act to inhibit crack propagation and increase fracture resistance through phase transformation [ 16 ].…”

Effect of Finish Line Design on the Fit Accuracy of CAD/CAM Monolithic Polymer-Infiltrated Ceramic-Network Fixed Dental Prostheses: An In Vitro Study

“…Flexible resin matrix ceramic (RMC) materials have recently been introduced in dentistry for the computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication of fixed indirect restorations, including single-tooth complete coverage crowns [1,2]. RMCs are purportedly able to overcome the shortcomings of traditional ceramics in that they can be applied directly after milling without the need for additional processing steps, such as firing, sintering, and glazing [2][3][4]. These materials are designed to combine the favorable mechanical properties of ceramic and resin into one single material, with flexural strengths and elastic moduli matching or being close to the natural tooth structure [4,5].…”

“…These materials are designed to combine the favorable mechanical properties of ceramic and resin into one single material, with flexural strengths and elastic moduli matching or being close to the natural tooth structure [4,5]. The polymer-infiltrated ceramic network (PICN) materials are a class of RMCs made up of a porous ceramic scaffolds infused with a mixture of urethane dimethacrylate (UDMA) and triethylene glycol dimethacrylate (TEGDMA) polymers [2][3][4][5]. Several recent studies have investigated different aspects of the PICN material related to its clinical application in restorative dentistry [3,[5][6][7][8][9].…”

“…The polymer-infiltrated ceramic network (PICN) materials are a class of RMCs made up of a porous ceramic scaffolds infused with a mixture of urethane dimethacrylate (UDMA) and triethylene glycol dimethacrylate (TEGDMA) polymers [2][3][4][5]. Several recent studies have investigated different aspects of the PICN material related to its clinical application in restorative dentistry [3,[5][6][7][8][9].…”