On these pages we would like to describe the production process of crowns. As you will see, there are various ways of producing crowns or any kind of prosthetics, depending on whether you want a cheap product of low quality or a perfect one, manufactured according to modern standards of science, highest level of aesthetics, biocompatibility, precision and durability.
Unfortunately a patient is able to judge the aesthetics of dental work but not the quality of material and precision, because even low quality and imprecise crowns can last a few months or even years, but then it is too late for any sort of recourse.
After studying these pages, you will be able to judge your dental treatment and the production process of your crowns.
Your health is important!
This patient had a simple veneer metal crown made of cheap alloy and covered with simple resin on the outside surface on her upper right incisor tooth. She was unhappy with the unnatural colour and the fact that the metal rim of the crown was visible in the cervical area. Because of the large filling in the second incisor, she asked for two new crowns.
The insertion of crowns puts an extraordinary stress on teeth. They are drilled, a lot of impressions are taken and they have to tolerate the fixing of temporary and final crowns. And if they are supposed to be abutment teeth for some bridge or other kind of prosthetics the stress level is even higher.
Therefore it is extremely important to clarify in advance, if the affected teeth will survive this procedure and how long they will last afterwards (prognosis) and if there are any other inhibiting factors infections, periodontitis, cysts, etc.)
This is managed by an intraoral inspection and a palpatoric examination with special instruments and by x-ray pictures, which facilitate an examination of the teeth under cariologic, periodontologic, endodontologic and prosthetic aspects.
Under no circumstances should the consultation or even examination be done by an incompetent person. A dental technician or dental assistant may be able to decide, that for example a tooth with an insufficient crown or filling needs a new crown. However, they neither posess the required knowledge based on university studies nor sufficient experience to be qualified for a correct examination of teeth, an exact judgement of x-ray pictures and therefore a reliable prognosis.
First we determined the colour and took some impressions for the production of the temporary crowns.
After the injection we removed the old crown. We found a large carious defect and had to put a titanium pin in the tooth for the following filling.
After the drilling of the two teeth, we took a high precision impression and sent it to our dental lab together with several other impressions and bite registrations.
At last we inserted some fluid resin into the first impression and placed it back into the patient’s mouth, where it hardened after a few minutes. After polishing we fixed temporary crowns on the teeth.
4. Lab production:
The technician uses dental gypsum for the production of casts.
After preparation of the teeth in the cast, the technician produced small caps made of wax, which were transformed into ceramic or high gold alloy.
Afterwards many different layers of ceramic were put on the cap and baked in the ceramic furnace.
Because of the various hues in the different areas of the crown and the use of transparent ceramics in the incisal area, you simply can’t tell these crowns from natural teeth.
Many steps are done under a microscope, to accomplish high precision and therefore long durability, because only a perfect fitting between crown and tooth guarantees, that no bacteria can move under the crown, which would sooner or later lead to loss of the crown or even the whole tooth. Unnecessary to mention that we use only high class materials for the production of this crown for an optimal biocompatibility.
Finally the crowns were fixed with a special adhesive. The result speaks for itself.
The human jaw is a multifunctional joint, which means it is capable of movements in all directions (lateral, forward and backwards) and not only for opening and closing movements. Normally there is harmony between the joints and surfaces of lower and upper teeth during movements of the upper and lower jaw under tooth contact, for example chewing.
Any disturbance of this harmony, for example caused by teeth malposition or misfit dental prosthetics, can sooner or later lead to a temporomandibular damage with serious consequences like strong head and neck pain or even balance impairment or tinnitus.
Therefore it is extremely important, that dental prosthetics harmonizes with the jaw in any possible movements and not only opening and closing movements. This is only possible, if the prosthetics is produced under functional analytical aspects.
Functional analysis is a registration of all individual parameters of possible jaw movements of the patient, which differ from person to person.
Afterwards these parameters are transferred into an adjustable articulator, which can simulate all jaw movements and in which the prosthetics will be produced, exactly fitting to the individual jaw situation of the patient.
The simple crown:
This crown is produced of cheap alloy with almost no gold or platinum inside and covered with only one layer of resin or ceramic on the outside surface.
After the production of the cast, the technician manufactures a crown of wax, which he transfers into a metal crown made of low gold alloy.
Afterwards one single layer of resin or ceramic is put on the outside surface. The crown is produced in a simple articulator, which is only capable of opening and closing movements but not able to simulate the individual movements of the patient. The lack of the functional analysis will sooner or later lead to temporomandibular damages.
At first glance the result is quite acceptable but can’t be compared to the full ceramic crowns. The use of low quality materials may lead to discoloration and to irritations of the gum and sense of taste. Besides these crowns are not manufactured under the same precision techniques like the high quality ceramic crowns, which reduces the durability and may require a new treatment after a few years.
MUNICH DENTAL CLINIC und LABOR ROFI:
As you can read in the other chapters of this website, the Munich Dental Clinic and the Rofi Dental Laboratory exclusively use most modern equipment, instruments and materials, which were entirely imported from Germany. Our products are of the same quality standards as in the best clinics and dental labs in Europe and the USA.