Bonding Strength of Lithium Disilicate Adhesive Crowns with Different Occluso-Cervical Preparation Heights and Cement Types

The aim of this study was to evaluate if adhesion technology with CAD/CAM can compensate for the reduction of occluso cervical preparation heights using different types of dental cement. The de-bonding failure types were then assessed. Here, 72 caries-free extracted human premolar teeth were prepared to have a remaining occlusal height of two, three, and four mm. IPS e.max lithium disilicate CAD/CAM crowns were cemented with adhesive resin cement Panavia SA, self-adhesive resin cement, RelyX Unicem Aplicap, and zinc phosphate cement. The cementation techniques were based on the manufacturer’s instructions. After thermocycling, all samples were tested for tensile bond strength via an Instron machine. One-way analysis of variance (ANOVA) with post hoc testing (P < 0.05) was performed. The means TBS for the two, three, and four-mm OCHP groups were 2.72±0.69, 3.06±0.82, and 3.25±0.79.0 MPa; ARC, SARC, and ZPC were 3.41±0.51, 3.45±0.41, 2.08±0.35 MPa, respectively with significant differences in both. The mixed cement had failures in the resin cement groups. Failure was predominantly cohesive in the zinc phosphate group. Resin cement had the highest SBS values versus ZPC values when both bonded to lithium disilicate crowns with different occlusal heights. The failure of the adhesive to the crown and/or to the tooth were the highest for the four types of resin cement. Around 25% were cohesive failures with resin cement, but this was predominately adhesive in crowns in zinc phosphate regardless of the preparation heights.

Preparation and Electrochemical Inhibition Properties of Ce3+-Photomodified Zinc Phosphate Materials

Breakthroughs in the intrinsic properties of environmentally friendly zinc phosphate materials for corrosion protection require the realization of new structures. The zinc phosphate material was effectively modified with rare earth...

The impact of surfactants on nanosphere zinc phosphate synthesis

Recently, biomaterials have attracted widespread concern because of their compatibilities with live bodies. Among advanced biomaterials, zinc phosphate nanospheres particles are potential candidates for delivering drug and dental restorations. However, their fabrication methods are complicated and non-eco-friendly. In this study, we report the impact of surfactant supplements on the wet chemical preparation of zinc phosphate. Experimentally, Di-propylene glycol (DPG) and Trimethylolpropane (TMP) were added to the solution in the preparation step to compare the morphology of synthesized particles with the non-surfactant process. The morphology was examined by transmission electron microscopy. The addition of surfactants changed particle shape to spherical with a diameter of less than 200 nm. Moreover, the synthesized particles with DPG had a solid form, while those with TMP had a hollow structure (a diameter of 50-70 nm and shell thickness of 5-7 nm). Furthermore, X-ray diffraction, Fourier transforms infrared, and Thermogravimetric analyses analyzed properties of hollow particles.

Defining-Measuring-Analysing-Improving-Controlling (DMAIC): Process and Improve Stability in Carbon Steel Industry

Phosphating is most common method for surface treatment and finishing of ferrous and nonferrous metal. It has excellent corrosion resistance, wear resistance, adhesion and lubricating properties besides its economic values and speed of application. Steel is one of the cheapest materials used in various industries and it requires corrosion resistance therapy. This study aims to provide possible solution to the rusty issue on carbon steel product by improving coating stability using Defining–Measuring–Analysing–Improving–Controlling (DMAIC) method. The result proposed that zinc phosphate coating material has to replace current iron phosphate coating due to the former is more corrosion time resistant than that of the latter.