Effect of cementation techniques on fracture load of monolithic zirconia crowns

Clinical outcomes of tooth-supported monolithic zirconia vs. porcelain-veneered zirconia fixed dental prosthesis, with an additional focus on the cement type: a systematic review and meta-analysis

“…In comparison to restorations made of PVZ, monolithic designs have a higher load-bearing capacity [ 92 ]. It is also important to point out that resin-based cements may increase the strength of zirconia restorations to fracture, with glass ionomer cements being usually associated with lower fracture strength [ 93 – 95 ], which is in accordance with the results of the present review—the rates of minor or major chipping, for either PVZ or MZ, were higher for when the prostheses were cemented with glass ionomer in comparison to adhesive resin cements. Another important issue is the distinction of zirconia crowns with different yttria contents (3 and 5 mol%), as 3 mol% zirconia crowns fracture at almost twice the loads of the 5 mol% zirconia crowns [ 93 ].…”

“…It is also important to point out that resin-based cements may increase the strength of zirconia restorations to fracture, with glass ionomer cements being usually associated with lower fracture strength [ 93 – 95 ], which is in accordance with the results of the present review—the rates of minor or major chipping, for either PVZ or MZ, were higher for when the prostheses were cemented with glass ionomer in comparison to adhesive resin cements. Another important issue is the distinction of zirconia crowns with different yttria contents (3 and 5 mol%), as 3 mol% zirconia crowns fracture at almost twice the loads of the 5 mol% zirconia crowns [ 93 ]. In this context, the authors of an in vitro study suggested that it would be wise to avoid pre-treatment of 5Y crowns with air abrasion, as this reduced the strength of these crowns, the same not happening with 3Y-crowns [ 93 ], although the authors of another in vitro study, although also showing a difference in fracture load between 3 and 5Y crowns, suggested that crowns fabricated from 5Y-Z may be particle abraded if luted with resin cements [ 94 ].…”

“…Another important issue is the distinction of zirconia crowns with different yttria contents (3 and 5 mol%), as 3 mol% zirconia crowns fracture at almost twice the loads of the 5 mol% zirconia crowns [ 93 ]. In this context, the authors of an in vitro study suggested that it would be wise to avoid pre-treatment of 5Y crowns with air abrasion, as this reduced the strength of these crowns, the same not happening with 3Y-crowns [ 93 ], although the authors of another in vitro study, although also showing a difference in fracture load between 3 and 5Y crowns, suggested that crowns fabricated from 5Y-Z may be particle abraded if luted with resin cements [ 94 ]. Unfortunately, it was not possible to make an analysis of either failure or complications in relation to the different yttria contents of the restorations, as detailed information about the zirconia material used was not always provided.…”

“…As there is still no clear consensus about the difference in performance between the use of these two cements for zirconia restorations, one can only hypothesize that the possible cause for these findings could be related to the downsides of resin cements. Adhesive bonding has the disadvantage of being technique sensitive, as multiple steps of pretreatment are required and the prepared surface can easily get contaminated [ 93 , 105 ]. Moreover, zirconia does not bond to resin-based cement as strongly as a silica-based ceramic [ 93 , 106 ].…”

“…Adhesive bonding has the disadvantage of being technique sensitive, as multiple steps of pretreatment are required and the prepared surface can easily get contaminated [ 93 , 105 ]. Moreover, zirconia does not bond to resin-based cement as strongly as a silica-based ceramic [ 93 , 106 ]. These factors could possibly have influenced the results.…”