Influence of Different Conditioning Protocols on Bond Strength to Glass Ceramic

Abstract

Objective: to detect the effect of different surface treatments on bond strength to machinable glass ceramic. Materials and Methods: Sixteen glass ceramic blocks (IPS e.max CAD/CAM) were fabricated by a CAD/CAM machine with dimensions (6mm × 11mm x 13mm) and divided into 4 groups (n=4), according to surface treatments: (G1) Hydrofluoric acid (HF) etching and silane application, (G2) Acidulated phosphate fluoride (APF) and silane application, (G3) Monobond Etch and Prime (MEP), (G4) Tetrabutylammonium dihydrogen trifluoride (TDTF) and silane application.Composite resin blocks (Te econome) were fabricated and cemented to the treated ceramic blocks using adhesive resin cement. All bonded specimens were kept in a water bath for three months and went through 5000 thermal cycles. The bilayered specimens were sectioned into micro-bars (1 mm* 1 mm in cross-section) using a diamond-coated disc under water cooling using a cutting machine. Microtensile bond strength (μTBS) test was performed. Scanning Electron Microscope (SEM) was used for specimens' examination. Results: HF with silane group shows the highest μTBS mean value (39.3±19 MPa) followed by Monobond Etch & Prime (33.0±11.5 MPa). On the other hand, APF with silane showed the lowest μTBS mean value (7.5±3.8 MPa).Conclusions: HF acid and Monobond Etch and Prime system are preferred to be used for surface treatment of lithium disilicate ceramics.

Adhesive Performance of Resin Cement to Glass-Ceramic and Polymer-Based Ceramic CAD/CAM Materials after Applying Self-Etching Ceramic Primer or Different Surface Treatments

“…In addition, it can lead to heat production, residual stresses, cracks, microchipping, and volume losses in the ceramic restorative materials that may cause flaws, reducing the bond strength [ 1 , 5 ]. As a chemical surface treatment method, etching with hydrofluoric acid (HF) and conditioning with silane primer is reported to be the gold standard for glass ceramics [ 10 , 12 , 13 , 14 ]. HF can induce surface micro-roughness by dissolving the glassy matrix and exposing the crystalline structure, thereby increasing micromechanical retention [ 3 , 10 , 15 ].…”

“…In addition, HF is highly dangerous due to its corrosive, reactive, and toxic nature. Direct contact with HF can result in tissue damage, rashes, burns, and even necrosis, so skin and eye protection is mandatory [ 6 , 10 , 13 , 14 ]. Moreover, because of this toxic potential, HF ceramic etching is even prohibited in some countries [ 12 ].…”