Prosthodontics

Prostheses in dentistry are used to reconstruct losses in the mouth, such as missing teeth, missing parts of teeth, and missing soft or hard structures in the jaw and palate. Prosthetic dentistry is the specialty of dentistry that deals with dental prosthetics. These types of prostheses are used to improve chewing, aesthetics and aid speech.

Prostheses are fixed to teeth or dental implants with dental adhesive or screws. Prostheses for partial or total edentulous mouths are applied by friction against the parallel hard surfaces and undercuts of the teeth or dental implants, creating a vacuum utilizing mucus secretion and using the surrounding muscles and anatomical contours of the jaw to passively hold them in place.

Who is Prosthetic Dental Treatment Applied to?

Dental prostheses can be applied to patients of all ages for function, phonation and aesthetic purposes in people with partial or total tooth loss in their mouth. It is also frequently used to replace the soft and hard tissues around the teeth.

Made to replace teeth, dentures can be held in place by attachment to teeth or dental implants, or held in place by vacuum and passively held in place by surrounding muscles. Like other types of body prostheses, they can be permanently fixed or removed; fixed dentures and removable dentures are made in many variations.

What are the Prostheses Used in Prosthetic Dental Treatment?

In general, 2 basic methods are applied in prosthetic dental treatment: "removable prosthesis" and "fixed prosthesis". Among these, removable prosthesis is divided into 2 subgroups. We can list them as follows;

Fixed Prostheses: Fixed prostheses can be used to replace partial tooth loss or loss of material in the teeth, especially in large quantities.

Inlays and Onlays: These are restorations that are prepared on a model in a laboratory environment with materials such as composite or porcelain and bonded to the patient's teeth to replace the loss of material in the teeth. They are often an alternative to dental fillings applied in the mouth. While inlays do not include the upper parts of the teeth called tubercles, onlays include the tubercles in the restoration. Since they are prepared in a laboratory environment, they have very good contact with the adjacent teeth, have high durability and are aesthetic.

Porcelain laminated veneers (PLVs): The primary use of PLVs is to improve anterior aesthetics by altering tooth morphology and color. PLVs are the least invasive of dental restorations, usually involving the buccal surfaces of anterior teeth. If the underlying tooth color is acceptable, only minimal tooth reduction is required to improve shape and color with a thin porcelain lamina fabricated in the dental laboratory. PLVs are the most commonly prescribed type of restoration.
However, it should be noted that it is controversial to prepare vital healthy teeth for PLVs with little aesthetic improvement for purely cosmetic reasons, especially if similar results can be achieved with less invasive protocols such as whitening or composite resin fillings.

Curons: It is a method used for excessive tooth loss. After the material losses in the teeth are replaced with an appropriate method such as filling, the teeth are reduced circumferentially to make room for the crown material to be made to protect the teeth. Crowns are prepared in the laboratory with a material suitable for the patient and bonded onto these reduced teeth. Crowns can also be applied for different reasons such as color changes, fractures in the teeth, alignment of the teeth located outside the tooth row. Different crown materials are used for these purposes. Among the most commonly used are feldspathic porcelain types, reinforced porcelains such as E max, zirconium, metal ceramics using metal and porcelain together, reinforced composites.

Braces: If there are a sufficient number of strong teeth in front of and behind the tooth gaps that can be supported, then bridge restorations can be used to complete the missing or missing teeth. By using the teeth in front of and behind the gap, the prosthesis that replaces the missing tooth can be hung over this gap. A single missing tooth or multiple missing teeth can be completed with these bridges. It is a method that requires the root and surrounding tissue of the teeth to be supported to be healthy.

Partial (partial) dentures: If there are many areas with missing teeth, if the length of the tooth gaps is too long or if the tooth gaps are not limited by any teeth, then partial dentures are used to eliminate tooth deficiencies. These prostheses consist of a main carrier on which the teeth are placed and parts used to provide retention of the prosthesis. The retention of the prosthesis can be provided by hooks placed on the teeth, called crochets, or by sensitive retaining parts that generally fit the key lock system.  The main carrier extends over the edentulous spaces to provide maximum tissue support. The prosthesis is attached to some of the existing teeth with the help of spacers. In this type of prosthesis, some or all of the existing teeth are covered with a crown prosthesis. Patients can remove and clean this prosthesis with very little force.

Total Dentures: In cases where all teeth are missing, the teeth are placed on a base and the base is spread over the widest area suitable for the oral anatomy. In this way, it is aimed to ensure maximum contact between the base and the patient's gums and to ensure the retention of the prosthesis. Many factors such as oral anatomy, the time of tooth loss, the amount of bone and soft tissue left behind, saliva, and the support of the surrounding muscles are effective in the success of such prostheses.

Implant Supported Prostheses: Implants are titanium screws in the shape of a tooth root. These prostheses can be fixed or removable. Instead of a single tooth, it can be used in partial tooth deficiencies or in cases of complete edentulism. It can be completely supported by implants or supported by both implants and tissue. The connection with implants can be made with the help of adhesives, screws or spacers. Generally, fixed implant-supported prostheses can be made by placing 4-8 implants in a single jaw, while both implant and tissue-supported prostheses can be made on at least two implants. Durable materials such as metal, porcelain, zirconium are used in implant-supported prostheses. 

Metal-Ceramics: Porcelains are not very strong on their own, so they are supported by a substructure. Metal has been used for this purpose for many years. It is quite durable. It is easily used for long bridges. To cover the gray color of the metal, a white substance called opaque is applied between it and porcelain. Aesthetically satisfactory results are obtained. The possibility of reflection of the gray color of the metal from the gums may cause aesthetic discomfort. It is not used in patients with metal allergy. Separation of the porcelain from the metal may cause aesthetic problems.

Porcelain: The main structure is clay. They are obtained by baking under vacuum at various degrees. They can be used for aesthetic purposes on substructures such as metal, zirconium or E max in the construction of crown blinds, or they can be used alone as crown, lamina, inlay-onlley material. Porcelains are hard glass structures that give a vivid appearance and do not undergo discoloration. They are also produced to be used as artificial teeth in removable prostheses. 

E-Max:The use of porcelain alone is limited. E-maxes are porcelain structures reinforced by various methods. They are used in the construction of crowns, short bridges, laminae, inlay-onlays. They are highly aesthetic materials since they can be produced without a substructure. Their gingival compatibility is very good. They harmonize aesthetically with the natural teeth in the patients' mouths very well. They are bonded with special adhesives. Color options are quite high.

Zirconium: Zirconium is actually the oxide form of the metal zirconium, which also appears in the periodic table. It is a white colored material. This eliminates the problem of metal reflection from the gums, which can cause aesthetic problems in metal-ceramics. Zirconium has very good compatibility with body tissue. It is used as a substructure material by applying porcelain on them. Since sufficient transparency has been achieved with the additional substances added to them in recent years, they can easily be used alone as crown and bridge materials. Since it is a white material, it allows less cutting from the tooth tissue. Since the risk of porcelain breakage will be eliminated in patients with teeth clenching and grinding, they can be used alone. It is also used as a substructure material in fixed prostheses on implants.  

What are Maxillofacial Prostheses?

Jaw and facial defects are deficiencies in the jaw and/or facial region, either congenital or due to acquired causes such as trauma or cancer. They are classified as upper jaw defects (maxillary defects), lower jaw defects (mandibular defects) and facial defects (facial defects). Defects in areas such as the eyes, nose, ears and cheeks are classified as facial defects. These defects can occur in a single area or in more than one area.

The treatment of jaw and facial defects can be performed both surgically and prosthetically. Both treatment modalities have some advantages and disadvantages compared to each other. The shape, size and etiology of the defects are the main factors in deciding the type of treatment. Surgical methods are generally preferred for small facial defects.