Application of welding wire in dental technology
In certain cases, the application of welding wire may be necessary, whether as preparation for a connection weld, as reinforcement for an already welded seam or simply to restore a missing contact on dentures (e.g. mesial, distal, occlusal, …).
The material used for building up a surface should consist of an alloy of the same type, usually a laser welding wire. In exceptional cases, e.g. with some palladium-based or palladium-silver alloys, the use of other alloys is recommended (in the above-mentioned case, welding wire made of a high-gold alloy, as palladium tends to become brittle during welding). We expressly advise against the use of low-melting dental solders.
It is generally advisable to follow the manufacturer’s recommendations when selecting welding wire, especially if the work requires a ceramic veneering afterwards (suitable CTE).
This is not quite so critical in a repair of a typical cast partial, and most non-precious dental alloys (e.g. cobalt-chrome alloys) are very similar in their composition and welding behavior.
We have had the best experience with welding wires that have a diameter between 0.25 and 0.5 mm. Larger diameters are often also available and can be used, but require higher parameters during welding, which means increased energy input and more heat development for the workpiece – this is not desirable in most cases.
However, if defects need to be bridged, thicker welding wires are very suitable, less as welded-on filler material, but much more as bridging material placed in between, which can be welded from two sides.
We recommend using a freshly ground electrode when starting with a build-up weld. Particularly for fine welds on thin parts or with low welding parameters, the electrode should always touch both the mostly round welding wire and the workpiece surface at the exact point of contact.
This only works well and in a controlled manner with a pointed tungsten electrode!
You can either contact the wire at its end or at the side in its course
as in the video linked below – both are possible and depend on the space available.
Welding wires of various alloys with a diameter of 0.35 mm can often be added well with parameters between 35 – 45 % power and between 4 – 6 ms pulse duration.
Welding geometry:
Video: Applying welding wire
You can also watch the process of applying a welding wire in this video.