Estudio comparativo in vitro de la resistencia adhesiva al cizallamiento de zirconia cementada a dentina con tres tratamientos de superficie

Abstract

Introduction: The use of machined zirconia (3Y-TZP) has become an ideal option at present, since mechanical properties are very high, in these restorations its cementation is mechanically-retentive with non-adhesive or low adhesion sealing cements . Objective: To evaluate, in vitro, the adhesive resistance to zirconia shearing, cemented with a self-etching resinous cement, to dentin with three surface treatments. Materials and methods: 60 premolar teeth sectioned in its middle third coronal, 60 blocks of monolithic zirconium, divided into three groups of experimental type, grouping 20, Group 1: 20 samples cemented with relyxU200 (3M) and previous surface treatment by sandblasting with oxide of aluminum 110 μm. Group 2: 20 samples cemented with relyxU200 (3M) and previous tribochemical treatment with Rocatec (3M). Group 3: 20 cemented samples with relyxU200 (3M) and previous surface treatment with first agent MDP Z-PRIME Plus (BISCO). The dental substrate was etched with enamel with scotchbond 3M ESPE phosphoric acid, washed with water and dried gently with absorbent towels. Cementation of the zirconia structures with Relyx U200 (3M) dual polymerized self-adhesive cement was performed. A uniform vertical seat pressure of 49 Newtons was applied with a constant load device for 6 minutes to standardize the cementation The strength of adhesion of the groups of samples was measured by the use of a universal load machine 94100 Unitek FIE, by applying a load in shear at the Zirconium / Tooth interface. The load was applied at a constant speed of 0.5 mm / min until a fracture occurred. Results: The highest value of shear resistance recorded among all the groups corresponds to the Z-Prime group with 1563.6 N and 27.6 MPa and the minimum value to the sandblasted group with 128.5 N (2.6 MPa). The highest average value was presented in the Z-Prime group with 889.9 N (15.9 MPa). Conclusions: Z-Prime plus and Rocatec surface treatments showed an increase in the adhesive strength of cemented zirconium with relyx u200 compared to the group Sandblasted with aluminum oxide, yielding average values ​​of 15.9Mpa, 8.9Mpa and 8.5Mpa respectively.