YY 0712-2009Dental ethyl silicate bonded casting investments (English PDF)

2.1 Investment powder

Designed for embedding casting dental casting alloy prosthesis with a powdered mixture of refractory filler system with the active ingredient thereof.

Note 1. refractory filler systems typically consist essentially of silica. The active ingredient is an alkaline oxide, usually magnesium oxide.

2.2 Investment liquid

Provided by the manufacturer or supplier of the liquid embedding material powder for reconciliation.

Note 2. Each system should specify the provisions of two to three kinds of special fluid. One solution contains ethyl silicate binder composition. Other supplements containing liquid into a rest Minute. All blended into a liquid binder liquid for investment material powder and reconcile.

Powder mixed with a binder to form a paste, forming a first silica gel, hardens, then converted to silicon dioxide.

3.3 Compressive strength

By 4.4 test compressive strength at room temperature embedding material is not less than 1.5MPa.

3.4 Linear thermal expansion coefficient

By 4.5 test, numerical linear thermal expansion coefficient and manufacturers should provide no greater than 15%. If the manufacturer provide for thermal expansion coefficient line Range, the measured value should be in the middle of the range no greater than 15%.

4.1 Overview

4.1.1 Sampling

Selection of unopened and undamaged packaging materials tested.

4.1.2 Test Environment

Reconciled with test shall be ± 2 °C at 23 °C, relative humidity of 50% ± 10% No significant ventilated environment. Selection of clean, dry