Dentists and dental technicians have to adapt to processing many different materials in their everyday lives. When attaching restorations, among other things, many questions often arise due to the variety of tooth-colored materials. As a supporting guide, Prof. Dr. Martin Rosentritt (University of Regensburg) developed a didactically beautiful overview graphic based on material science aspects. Dentists and dental technicians can see at a glance which material is processed, cleaned, conditioned and ultimately attached.
Attach correctly: Scientific background as a concept for success
Basically, the attachment depends on the properties of the restorative material. Ceramics, zirconium oxides, composites, hybrid materials…. How is which material prepared, conditioned and ultimately attached to the natural tooth? The answer lies in materials science.
The compass developed by Martin Rosentritt clearly outlines the topic. The various materials are graphically assigned how they should be processed, cleaned, conditioned and fastened. A detailed publication on the topic will soon be published in Quintessenz Dental Technology (Quintessenz Verlag, Berlin).
Some tips for everyday laboratory and practice life:
- Processing the zirconium oxide framework: Every processing results in a defect in the surface and can cause cracks to form. The zirconium oxide surface should only be lightly roughened and with low blasting pressure (50µm at 1,5-2 bar).
- Framework try-in for zirconium oxide framework: Agents such as silicone oil or petroleum jelly should be avoided. Better: Water-based materials, such as glycerin gel or try-in pastes.
- Surface cleaning: Glass-based ceramics can be cleaned with phosphoric acid. For example, a special cleaner is recommended for zirconium oxide surfaces. Steam or ultrasound with alcohol is well suited for degreasing.
- Conditioning for adhesive bond: Due to the chemical processes of primer and bonding, it is recommended to always stay in a product chain. For example, MDP primer is used for zirconium oxide. Alternatively, the surface can be glazed and then etched. Note: Not all spray glazes are etchable.
- mounting materials: The requirements include stability, adhesion, sealing and optimal force distribution. The following applies: Materials with a strength of 350 MPa or more can be cemented conventionally due to their high inherent stability. Weaker materials must be bonded adhesively.
Annett Kieschnick, specialist journalist