Aim: To compare by means of optical thickness of the cement interface at different levels of biological preparedness Procera-zirconium cores using different cementing agents.
Materials and methods: 40 healthy premolars recently extracted, caries-free and kept constantly hydrated were carved for fixed prosthesis metal-free unit, were scanned for making by CAD-CAM process zircon cores for each of them. The preparations were divided into five groups of eight samples each. The cement used by the group were: RelyX ARC (RA), Ketac Cem (KC), RelyX Unicem (RU), Multilink (ML) and Panavia F2.0 (PAN), respectively. The samples were cut with the machine Isomet for observation
Results: The interface of cementation was measured cervical, free and occlusal sides. Averages for cervical were: RA (53.75μm), KC (20 mM), UK (18.13μm), ML (31.25μm), PAN (25.63μm), for free surfaces: RA (100μm), KC (72.50μm) , RU (68.75μm), ML (66.88μm), PAN (63.13μm), for occlusal RA (200μm), KC (130 μm), UK (171.25μm) ML (202.50μm), PAN (186.25μm) . The results were subjected to statistical analysis (One-Way ANOVA and Tukey). At free expensive cervical and interface thicknesses were greater and statistically significant for cement RA versus other cements, at occlusal thicknesses were lower and statistically significant interfae for cement KC in relation to the other cements.
Conclusion: The cements that require pre-conditioning of the tooth surface have a greater thickness of the cement line.