Crowns & Bridges
If the tooth is destroyed by caries so much, that it is impossible to repair the tooth with a filling that the full function and form is regained, it is necessary to cap the whole tooth. The artificial crown covers the –first freed from caries and with composite reconstructed- primed snag. There are 4 different kinds of crowns.
Since the crowns have a metal color they are only – if at all – used at the posterior teeth.
Using the porcelain bonded crowns it is possible to rebuild the tooth –optically – lifelike. For this method a tooth-coloured porcelain material is burned onto a noble metal-crown
Disadvantageous is that caused by different lights the metal crown underneath the porcelain is sometimes visible. This disadvantage can most of the time be removed by an individual layer of porcelain.
Another disadvantage is that if the tissue of the gums decreases a little bit the metal edge is visible. This disadvantage can be removed by producing a porcelain shoulder. This method is nevertheless really complex because in the edge area another step needs to be primed.
Compared to the porcelain bonded crown, where the basis of the crown is still metal, the zirconium oxide crown is based on zirconium oxide. Therefore a precise sharpening robot shapes the basis out of a stable industrial build zirconium oxide block. The later-on burn-up of the porcelain works similar to the procedure to the porcelain veneer crowns. Since this kind of crowns is metal free it is a possible alternative for metal-allergic people. Compared to the cast-crowns they are fixed conventional, means that they can also be used if the defect reaches far underneath the tissue of the gums.
Full porcelain crowns are –like the name already says- free from any metal. This kind of crowns is mostly used for front teeth. They work aesthetically really well since if light hits the teeth it can shine through. The production of this kind of crown is even more complex than the production of the galvano-crowns. She represents for both dentist and dental laboratory the most difficult kind of Provision.
To close teeth gabs in a denture is the main duty of tight artificial dentition. If a tooth gap remains unprovided over a longer period of time, other teeth from the opposing dentition grow into this gap. Furthermore the possibility is given that the neighbor teeth tilt over into this hole. The stability of the denture is getting lost. Is the tooth gap in the posterior region the chewing function is affected and even digestion problems can occur. If a front teeth gets lost language function and the appearance is affected.
A bridge is made out of abutment crowns, which are put onto the tooth gap neighbor teeth, and a bridge Pontic which closes the gap. Just like the crowns there are cast-bridges, porcelain veneer bridges, galvano bridges and full porcelain bridges.