Laminat Vener Restorasyon Yapımında Kullanılan Farklı Yüzey Pürüzlendirme İşlemleri Uygulanmış Cad/Cam Materyallerinin Mineye Olan Makaslama Bağlanma Dayanımı

Abstract

ABSTRACT Meral, YE. Hacettepe University Institute of Health Sciences, Ph.D. Thesis in Prosthodontics, Ankara, 2015. The Effects of Various Surface Treatments for Laminate Veneer Indicated CAD/CAM Block Materials of Feldspathic, Nanocomposite and Hybrid Ceramic on Shear Bond Strength to Enamel. The purpose of this in-vitro study was to assess the effects of various surface treatments, on the surface roughness, shear bond strength to enamel and failures modes of different CAD/CAM block materials that have laminate veneer indications. The surface treatments were grouped as follows: (1) grinding with 125 grit silicone carbide sandpaper, (2) Nd:YAG laser treatment, (3) etching with 4% hydrofluoric acid, (4) etching with 9.5% hydrofluoric acid, (5) air particle abrasion with 110 μm Al2O3, and (6) tribochemical treatment with 30 μm silica coated Al2O3. Surface roughness measurements were performed with a profilometer on 6x6x1 mm specimens. 180 caries-free and sound human maxillary central and lateral incisors were randomly distributed into 18 groups (n=10). After embedding into acrylic resin, intaglio surfaces were prepared on enamel. 4x4x2 mm specimens were prepared from each CAD/CAM block material and tested surface treatments were applied to the cementation surfaces. Bonding to enamel was achieved with a dual-cure adhesive resin cement application. Samples were stored in 37°C distilled water for 24 hours, and shear bond strengths were experimented. Fracture strengths were experimented with of 1.0 mm/min, till the debonding load is reached. The debonded surfaces, both on specimen and enamel, were observed with a 3X loop and modes of failures were determined as adhesive, mixed and cohesive. Statistical analysis was made with SPSS 21.0 for IBM. Kruskal Wallis test, Mann Whitney U test and Correspondence Analysis were used in order to evaluate the level of significance (p<0.05). Surface roughness values varied between 0.80 μm and 3.11 μm, while shear bond strength values varied between 3.78 MPa and 23.50 MPa. The highest Ra values were recorded for 110 μm Al2O3. The roughest and the strongest groups were of nanocomposite CAD/CAM block material (LU). CAD/CAM block materials of feldspathic (SC) and hybrid ceramic (VE) showed adhesive failure tendency, while nanocomposite LU caused cohesive tendency. Keywords: Adhesive dentistry, CAD/CAM, esthetic restoration, new ceramic/polymer materials, surface conditioning. Supported by H.Ü.B.A.B. Thesis grant, PhD (TDK-2015-7948).