The Effect of Hydrofluoric Acid Etching Duration on the Surface Micromorphology, Roughness, and Wettability of Dental Ceramics

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The Effect of Hydrofluoric Acid Etching Duration on the Surface Micromorphology, Roughness, and Wettability of Dental Ceramics

The current laboratory study is evaluating the effect of hydrofluoric acid etching duration on the surface characteristics of five silica-based glass ceramics. Changes in the pore pattern, crystal structure, roughness, and wettability were compared and evaluated. Seventy-five rectangularly shaped specimens were cut from each material (IPS e-max (TM), Dentsply Celtra (TM), Vita Suprinity (TM), Vita mark II (TM), and Vita Suprinity FC (TM)); the sectioned samples were finished, polished, and ultrasonically cleaned. Specimens were randomly assigned into study groups: control (no etching) and four experimental groups (20, 40, 80 and 160 s of etching). The etched surfaces' microstructure including crystal structure, pore pattern, pore depth, and pore width was studied under a scanning electron microscope, and the surface roughness and wettability were analyzed using a non-contact surface profilometer and a contact angle measuring device, respectively. The results were statistically analyzed using one-way analysis of variance (ANOVA) and the post hoc Tukey's test. The results showed a significant change in the pore number, pore pattern, crystal structure, surface roughness, and wettability with increased etching duration. Etching for a short time resulted in small pores, and etching for longer times resulted in wider, irregular grooves. A significant increase in the surface roughness and wettability was observed with an increase in the etching duration. The findings also suggested a strong association between the surface roughness and wettability

Preliminary fabrication and characterization of electron beam melted Ti-6Al-4V customized dental implant

The current study was aimed to fabricate customized root form dental implant using additive manufacturing technique for the replacement of missing teeth. The root form dental implant was designed using Geomagic (TM) and Magics (TM), the designed implant was directly manufactured by layering technique using ARCAM A2 (TM) electron beam melting system by employing medical grade Ti- 6Al-4V alloy powder. Furthermore, the fabricated implant was characterized in terms of certain clinically important parameters such as surface microstructure, surface topography, chemical purity and internal porosity. Results confirmed that, fabrication of customized dental implants using additive rapid manufacturing technology offers an attractive method to produce extremely pure form of customized titanium dental implants, the rough and porous surface texture obtained is expected to provide better initial implant stabilization and superior osseointegration. (C) 2016 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University

Micro and Nano Structural Analysis of Dental Ceramic and Luting Resin Interface and the Effect of Water Exposure on Integrity of Cement Interface

The current study was aimed to evaluate-by micro and nano-structural analysis-the interface between dental ceramic and resin materials. The degree of resin impregnation into the etched micro patterns, the nano-mechanical properties of the resin-ceramic interface and the effect of subjecting to exposure in boiling water on resin-ceramic interface were studied. Three silica based glass ceramics were compared and contrasted: twenty samples from Computer Aided Design (CAD) blocks of each material were prepared. The specimens were finished, polished, ultrasonically cleaned, and etched with suitable acid. The specimens were randomly divided into two study groups to evaluate the effect of primer on resin cement impregnation. Each group of specimens were further divided into two subgroups to compare and contrast the difference in resin impregnation between adhesive resin and resin composite cement. The resin-ceramic interface was examined under scanning electron microscope and nano-mechanical properties were analyzed using a nano-indenter. The results were statistically analyzed using multivariate analysis of variance, a post hoc test, and regression analysis at a significance level of p<0.05. The results showed better resin impregnation of adhesive resin on primer treated specimens than resin composite cement. The specimens with the primer treatment and application of adhesive resin exhibited higher elastic moduli (46.07 GPa) and nano-hardness (2.02 GPa) even after subjecting to exposure in boiling water

Evaluation of an experimental silane primer system in promoting adhesion between orthodontic bracket and ceramic

The aim of the study was to evaluate in vitro the effect of an experimental silane primer system on the adhesion strength of metallic orthodontic brackets bonded to a ceramic surface. For this purpose, a total of 180 glazed ceramic porcelain fused to metal (PFM) veneer were randomly assigned into 2 groups of 90 specimens, according to the primer used. Each group was further divided into 3 subgroups according to the surface treatment to be received, thus there were 6 study groups; three with 3-acryloxypropyltrimethoxysilane (ACPS) silane primer, namely 1a (pretreatment with hydrofluoric acid, HF), 1b (pretreatment with grit-blasting) and 1c (pretreatment with tribochemical silica-coating) and 3 with a novel silane system (ACPS+bis-1,2(triethoxysilyl) ethane (BTSE)) assigned as 2a (HF), 2b (grit-blast), and 2c (tribochemical silica coating). The samples were evaluated for surface roughness (Ra) before and after surface conditioning. Next, 15 samples from each subgroups were subjected to thermo-cycling and remaining 15 samples served as the baseline (n = 15). Adhesion strength (the shear bond strength, SBS) was recorded using a universal testing machine. Debonding failure types were classified according to the adhesive remnant index (ARI). Contact angles of the primers were measured. Data were analyzed by ANOVA and Tukey’s multiple comparison post hoc analysis. The highest SBS at baseline (26 8+1 7 MPa) and after thermocycling (24 6+1 7 MPa) was observed in group 2c, and the lowest (9 6+1 5 MPa and 4 5+1 1 MPa) was found in group 1a. Specimens pretreated with tribochemical silica-coating exhibited the highest Ra and the lowest Ra was observed in HF treated specimens. The application of experimental silane primer system on specimens pretreated with tribochemical silica-coating demonstrated increased adhesion of orthodontic brackets making it an excellent choice in orthodontic bonding for a relatively long term use