Preliminary examinations of the raw materials (grain sizes, etc.)

The fabrication of high grade dentures includes such things as the quality of the investment materials.

The basics are:

• the recipe of the investment material
• the used raw materials
• the reproducibility in the manufacture

For quality assurance, each delivery of raw material is checked by the in-house chemistry lab. Specifications were negotiated with the raw materials suppliers in order to reduce fluctuations of the finished investment materials to a minimum.

Storage

The Dentaurum production plant provides ideal conditions for these requirements. The complex equipment operates as a closed system with low dust and contamination. The silos have been installed inside the building for the protection of the partially hygroscopic raw materials and equipped with filters, vibration base, feeder worm screws and dosing screws with coarse and fine switching for a uniform dosing.

Mixture

The required components for the investment materials are transported with high weighing accuracy and dosing precision by way of a special conveyor scales into the mixer. Processor controlled automated systems ensure highest accuracy in adhering to recipes within very close tolerances for a reproducible quality.

Examination of the expansion

A dilatometer serves for the examination of the thermal expansion.

Batch tests

No batch of investment material leaves the factory unless it passes the entire set of demanding tests by the chemistry lab and the prosthetic department. The technical examination according to the standard EN ISO 15912 includes characteristic values such as flowability, initial setting, compressive strength and thermal expansion. In addition, a batch test follows by the dental technicians with a practical casting object according to the current instructions. The following aspects are evaluated: processing consistency, thermal stability, accuracy of fit and surface smoothness of the cast.

Test specimen

A test specimen helps with the batch test to check the fit of the single crowns as well as the total fit of the bridge.

Packing and shipping

Till all results correspond with the demands on quality, the investment materials are released for sale and packed for the worldwide shipment.