Eggshell provisional
Provisionals are primarily intended to protect ground teeth until the healing process is complete and the final restoration can be placed. This healing phase can last six weeks or longer. Consequently, the provisional also fulfills an aesthetic and phonetic purpose.
Eggshell provisionals are also used to test the function, phonetics and aesthetics of the dentures for patients and are therefore also referred to as therapeutic or diagnostic care.
Types of provisionals
When it comes to provisional restorations, a distinction is made between immediate and interim restorations. While the immediate prosthesis is made before the teeth to be replaced are extracted, the interim prosthesis is made after their extraction.
Direct provisional
It is possible to receive a provisional directly from the dentist. With this so-called direct provisional, an impression – also known as a silicone key – is taken before the preparation of the abutment. This is filled with auto-polymerizing material in the abutment tooth area and placed in the mouth.
Eggshell provisional
The so-called eggshell temporary is also made before the preparation of the abutment teeth, but differently as the direct provisional by the dentist on site, it is made in dental laboratories by dental technicians. The manufacturing of an eggshell provisional was associated with enormous effort when using conventional dental technology. The advent of digital dental technology brings with it a great time advantage in this area as well.
But not only the time advantage pays off. Eggshell provisionals can be designed extremely thin (wall thickness of 0.3 mm). This makes it easy to fit in the patient's mouth.
Advantage of the eggshell provisional over the direct provisional
Advances in CAD / CAM technique in dental technology mean eggshell provisional restorations can be produced quickly and without great effort. Since the manufacturing takes place in the dental laboratory, valuable chair time is also freed up for practitioners and patients are less strained.
Compared to a direct provisional, an eggshell provisional offers additional aesthetic and health benefits. Since the resin hardens in the patient's mouth when a direct provisional is fitted, the ground abutment teeth are loaded with free monomer from the auto-polymering material. On the other hand, the CAD / CAM-made eggshell provisional restorations are milled from monomer-free resin (e.g. FAB Polymer). This resin is available in different tooth colors and also in multi-layered colors.
In contrast to direct provisional restorations, eggshell provisional restorations formed by dental technicians can also consider pontics and entire bridges can be fabricated in the form of an immediate restoration. The know-how available in the dental laboratory also makes it possible to introduce changes in the position of the teeth and to create gap closures, so that a displacement of the teeth is ruled out until the definitive restoration is made and the ground abutment teeth are protected from thermal, chemical, bacterial and mechanical influences.
The aesthetic design of eggshell provisionals is a particular advantage for the patient. Here, wishes can already be expressed and agreements can be made, which should later also bring the definitive fitting with it. If these wishes turn out to be problematic when wearing the temporary, this can be taken into account in a later definitive restoration.
CAD software for eggshell provisionals
With the leading service providers in the field of dental CAD software, virtual modeling of eggshell provisional restorations is possible without any problems. While the function is already included in the 3Shape software for crowns and bridges, the provisional module has to be purchased for exocad. Experienced and resourceful dental technicians can also solve it with exocad using the crown and bridge module.
Do you have questions about eggshell provisional restorations or other dental technology topics? Then get in touch with us. Our experts will be glad to advise you!