摘要:
To apply a silicon oxide adhesion-promoting layer to a metal prosthesis part or frame, for subsequent application of a dental plastic thereon, the prosthesis is subjected to flame hydrolysis derived from a flame hydrolysis burner (11) which has a silicon compound in vapor or gas form applied thereto in addition to a carbon-containing combustion gas, such as propane and air, the prosthesis part or frame being passed through the flame from the burner in the forward third thereof, the burner flame cone having, in operation, a length (L) of between 15 to 20 cm, a gas stream speed of about 1 m/sec., and wherein the length (L) of the cone exceeds the spacing distance (D) of the farthest part of the prosthesis from the mouth of the burner by only up to about 25%. For fine adjustment of the cone, a tinting substance can be added to the flame.
摘要:
Firmly adhering, durable dental metal/plastic composite structures that are stable in the presence of moisture can be made from dental alloys and plastics, if an adhesion promoting layer having a concentration gradient and comprising silicon dioxide and metal oxide, particularly chromium oxide, is disposed between them.
摘要:
Micaceous-cordierite-glass ceramic particularly suitable for stomatological, head surgery and neck surgery applicatiosn has a fracture toughness K.sub.IC of up to 2.0 MPa m.sup.1/2, a hardness HV.sub.0.07 of 300-1000, a compressive strength of up to 450 N/mm.sup.2, a linear thermal expansion coefficient of 75-125.times.10.sup.-7 K.sup.-1, good chemical stability and excellent machinability as well as a high resistance to wear and comprises a composition in weight percentages of______________________________________ SiO.sub.2 43-50 Al.sub.2 O.sub.3 26-30 MgO 11-15 R.sub.2 O 7-10.5 F.sup.- 3.3-4.8 Cl.sup.- 0.01-0.6 CaO 0.1-3 P.sub.2 O.sub.5 0.1-5 ______________________________________ wherein R.sub.2 O is the sum of 3 to 5.5 wt. % Na.sub.2 O and 4 to 6 wt. % K.sub.2 O, a first crystal phase of mica, and a second crystal phase of 5 to 30 volume % cordierite, wherein relatively large mica crystals of 10 to 200 .mu.m are embedded in the glass and cordierite crystals of 0.5 to 5 .mu.m are arranged in the glass.