When the situation in the oral cavity is such that fixed prostheses are not feasible, dental medicine offers the possibility of removable or combined works. Removable prostheses can be total or partial. While total prostheses are exclusively made of acrylic, partial prostheses can be made of two types of material: acrylic or wirе-on (with metal base). The solution proposed depends primarily on the condition of the patient’s oral cavity.
Cover prosthesis on implants
An ideal solution for a prosthetic rehabilitation of a toothless oral cavity. In comparison with a total fixed prosthetic replacement, the cover prosthesis requires fewer placed implants, which, along with a greater possibility of the implementation of the planned therapy (based on the quantity and quality of the remaining bone structure), and a less invasive intervention, greatly decreases the financial aspect of the therapy as well.
The main retention element is the bar. Fixed on four previously placed implants, it makes a primary (inverse matrix), while a secondary (matrix) is placed inside the prosthesis. Along with great retention and a completely reduced prosthesis base, the cover prosthesis on implants offers an ideal prosthetic replacement, comfortable for the patient.
Total and partial acrylic prosthetics
A total acrylic prosthesis is a removable prosthetic replacement made from acrylic. It is the only solution for a prosthetic rehabilitation of a toothless oral cavity if implants are not an option. Retention elements are soft gingival and firm bone structures, as well as negative pressure and resilience of mucous membrane.
A partial acrylic prosthesis is most commonly used as a temporary solution for the lack of individual teeth. It differs from a total prosthesis in the retention obtained by cast posts around existing teeth.
Combined prosthetics are partially fixed in the mouth, while the rest of the prosthetic is mobile and should be removed for oral hygiene maintenance.
Zirconium oxide ceramics
Zirconium is a relatively new material in dental medicine and certainly the biggest discovery concerning the metal ceramic crowns. Zirconium, as a material, is biocompatible, it does not react to surrounding tissues, it is a weak heat and electricity conductor that minimizes teeth oversensitivity and it is an unfavorable base for plaque build-up, which greatly improves oral hygiene care and slows down gingival recession.
Along with the mentioned advantages, zirconium is a material strong enough to bear chewing forces of the lateral region without getting fractured, and does not have a metal base.
The aesthetic characteristics are exceptional and give technicians the possibility to model a crown that is difficult to distinguish from a natural tooth.
Metal-free ceramics (PRESS)
It is used exclusively in the frontal region in order to achieve high tooth aesthetics in the shape of a crown or with minimally invasive facings technique (veneers). Since there is no base that gives it firmness and strength it is not suitable for lateral regions because of the strong chewing forces.
The metal ceramic crown consists of a metal base (cobalt – chrome – molybdenum, nickel – titanium, gold) fused with ceramic in special laboratory conditions. This enables the crown to assume the shape of a tooth, with satisfactory aesthetic results. Due to the resistance of the metal base and the ceramic aesthetics, metal ceramic crowns and bridges are used in both lateral and frontal regions. It is one of the golden standards with frequent usage in fixed prosthetics.
Combined prosthetic replacements
If the remaining teeth condition is favorable, there is a possibility to modify the dentures in a manner that the hooks are replaced by so called attachments. In this case, the remaining teeth are covered by metal-ceramic crowns, forming a bridge with articulated ends achieving retention by patrix – matrix principles with the dentures and their attachments system. This is available as a combination of fixed and mobile prosthetics.