Marginal adaptation of lithium disilicate ceramic crowns cemented with three different resin cements
The cementation process and cementation materials have an influence on the marginal adaptation of restorations. The gap could be affected by thermal and mechanical loading (TCML). The computerized x-ray microtomography (μCT) method offers the possibility of measuring the marginal gap without destruction of the restoration. The aim of this study was to evaluate the marginal gap (MG) and the absolute marginal discrepancy (AMD) before and after TCML.
Materials and methods
Thirty-nine human premolars were prepared for full ceramic crowns made of lithium disilicate. The crowns were cemented by three different resins—Panavia F 2.0, Variolink II, and Relyx Unicem. The MG and AMD were evaluated by μCT before and after TCML.
Panavia F 2.0 had the lowest MG (before 118 μm–after TMCL 124 μm) and AMD (before 145 μm–after TMCL 154 μm), followed by Relyx Unicem (MG: before 164 μm–after TCML 155 μm; AMD: before 213 μm–after TMCL 209 μm) and Variolink II (MG: before 317 μm–after TMCL 320 μm; AMD: before 412 μm–after TMCL 406 μm). The differences were statistically significant before and after TCML. Rather than TCML, it appeared the resin cement was responsible for differences between the MG and AMD before and after TCML.
μCT is an accurate technique for assessing cemented restorations. Panavia F 2.0 has the lowest MG and AMD before and after TCML.
The resin material that features a three-step protocol (Variolink II) produced higher MG and AMG values than the Panavia or Relyx Unicem varieties with less or no intermediate steps at all.
KeywordsμCT Marginal gap Cementation Absolute marginal discrepancy Full ceramic In vitro
We thank the software producer, SOFD, who supported this study by developing the evaluation software for the μCT scans free of charge, and the dental laboratory, Ruebeling and Klar, which supported our work by fabricating the all-ceramic crowns for free.
Author Triantafyllos Mitsas was supported by the Research Community Dental e.V., Cologne.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
For this type of study, formal consent is not required.
- 7.Pjetursson BE, Sailer I, Zwahlen M, Hammerle CH (2007) A systematic review of the survival and complication rates of all-ceramic and metal-ceramic reconstructions after an observation period of at least 3 years. Part I: single crowns. Clin Oral Implants Res 18(Suppl 3):73–85CrossRefPubMedGoogle Scholar
- 30.Stappert CF, Dai M, Chitmongkolsuk S, Gerds T, Strub JR (2004) Marginal adaptation of three-unit fixed partial dentures constructed from pressed ceramic systems. Br Dent J 196:766–770; discussion 760 quiz 780Google Scholar
- 33.Neves FD, Prado CJ, Prudente MS, Carneiro TA, Zancope K, Davi LR, Mendonca G, Cooper LF, Soares CJ (2014) Micro-computed tomography evaluation of marginal fit of lithium disilicate crowns fabricated by using chairside CAD/CAM systems or the heat-pressing technique. J Prosthet Dent 112:1134–1140CrossRefPubMedGoogle Scholar
- 34.Mounajjed R, D ML , Azar B (2016) The marginal fit of E.max Press and E.max CAD lithium disilicate restorations: a critical review. Dent Mater J 35:835–844Google Scholar