08 May 2019

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Adhesive or conventional luting for single crown cementation ?

Lorenzo Breschi

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Nowadays, the material of choice for single tooth full crowns restorations are lithium disilicate ceramic and zirconia. Both materials are very popular and could be veneered with feldspathic ceramic or used as a monolithic restoration, offering many different and equally efficient approaches to restore posterior as well as anterior teeth. However, as regards cementation the use of an adhesive based approach or a conventional cementation protocol is still a controversial issue. 
Adhesive resin cementation, as shown in different in vitro studies, could increase the retention and the fracture resistance of lithium disilicate crowns and improve the fatigue resistance of zirconia crowns. However, it involves a technique-sensitive, multi-step procedure that could be problematic in the case of subgingival crown margins or when the intraoral conditions cannot be controlled adequately. In these cases conventional cementation may be considered an acceptable alternative to adhesive cementation, being less clinically demanding. 

MATERIALS AND METHODS 
A recent systematic review, authored by Maroulakos G. and his team, analyzed the clinical performance of tooth-supported ceramic crowns and described the complications/failure characteristics when adhesive or conventional cementation was employed. 2571 relevant studies published between 2008 and 2018 were identified using several electronic databases. 

RESULTS 
From the titles yielded, only 17 articles met the eligibility criteria and were included into the qualitative analysis. The analysis reported that the survival rates for adhesively cemented lithium disilicate crowns ranged from 83.5% to 100%, whereas the survival rate reported for conventionally cemented lithium disilicate crowns was 98.5%. Survival rates for adhesively cemented zirconia crowns ranged from 83.3% to 100%, whereas those reported for conventionally cemented zirconia crowns ranged from 82.0% to 100%. 
The most common complication reported for zirconia crowns was mechanical and involved fracture of the veneered ceramic both for adhesively cemented and conventional cemented crowns. This complication could be related to the thickness of the veneer, the design of the zirconia core, or the core-veneer thickness ratio and may not be related to the type of cement.     

CONCLUSIONS 
The authors conclude that, based on current evidence, adhesive and conventional cementation results in comparable clinical outcomes for both lithium disilicate and zirconia tooth-supported single crowns. 

For additional informations: 
Effect of cement type on the clinical performance and complications of zirconia and lithium disilicate tooth-supported crowns: A systematic review. Report of the Committee on Research in Fixed Prosthodontics of the American Academy of Fixed Prosthodontics