Prosthodontics
Prosthodontics has the purpose to rehabilitate or maintain the oral function of the patient by restoring chewing, esthetics and phonetics through the use of veneers, crowns and/or dental prostheses.
The most common procedures in Prosthodontics include fixed treatments such as veneers, crowns or fixed partial prostheses over teeth or implants and they can be single, partial or total. The treatments may also be removable, partial or total through the use of acrylic or skeletal prostheses.
Contrary to the execution of a crown over a natural tooth, a crown over an implant does not require the wear and grinding of any structure directly on the oral cavity in view of the fact that the implant only substitutes the absent root and the crown over the implant substitutes all of the tooth crown. However, making the crown over the implant also involves an impression (mold) that is carried out by coupling an impression coping to the implant. The use of provisional crowns is not mandatory; through it may be decisive in clinical cases involving esthetic requirements (front tooth), functional adaptation (phonetics- absence of all teeth) or the adaptation or manipulation of the gum tissues. The final crown is finished at the laboratory in the shape and appearance of a natural tooth, being joined to the implant by means of an abutment with dental cement or an abutment with a screw.
As with crowns on natural teeth, the cosmetic objective is to produce a crown as if it was a natural tooth passing through the gum.
Crowns over teeth may be a good option if your teeth have been severely destroyed, worn, restored or if they require major changes in terms of size, shape, alignment or color. Before carrying out any prosthodontic rehabilitation, whether it is a single, partial or total case, your dentist must perform a diagnostic waxing (simulation of the final result and respective necessary alterations) so as to understand and indicate the best treatment plan in the case. This treatment plan may involve joint treatment with various fields of Dental Medicine such as Orthodontics, Endodontics, Periodontology and Implantology. Fixed partial prosthesis or crowns over implants are the best option in cases of the absence of one or more teeth or even in the case of total loss of teeth. As the placement of implants entails the presence of bone, before carrying out rehabilitation with implants, there may be the need to perform auxiliary diagnosis exams such as a CT scan.
Crowns over teeth or implants must be viewed like natural teeth. In the case of crowns over natural teeth, caries may still continue to appear under the crown at the interface between the crown and the tooth. In the case of the crown over the implant, inflammation may arise and/or infection at the crown/implant interface level. This is why it is very important to maintain good Oral Hygiene through proper brushing, the use of dental floss or tape and an interdental toothbrush and periodic dental appointments for radiographic clinical control thereof. As they are frequently made of ceramic, crowns may crack. You must avoid chewing hard things like ice or boiled sweets and keep parafunctional habits like biting your nails and pens. In some situations it may be necessary to use a mouth protector so as to prevent and protect crowns from cracking, particularly if you have the habit of grinding or clenching your teeth.
Usually called dentures, they are used to replace one or more missing teeth and soft tissues support and they may generally be made from two different materials, totally of acrylic (acrylic prosthesis) or metal-acrylic (skeletal prosthesis). Prostheses may be total or partial depending on the number of teeth they are replacing. They are usually supported by mucosa (gum) or teeth and they may also be supported by implants. As with fixed prosthodontics treatments, they require regular maintenance by the dentist and special care in terms of Oral Hygiene owing to the increased risk of caries on support teeth or infection in the support implants.
A crown (cap) is a type of restoration that involves a tooth or is joined to a dental implant. Crowns restore or alter the esthetic appearance and function of absent teeth, such as in implant situations, or are very decayed, cracked, worn or poorly positioned as in the cases of natural teeth. Crowns are also indicated in cases of teeth with large cavities or restorations that compromise tooth resistance such as, for example, teeth that have been submitted to endodontic treatment. A fixed partial prosthesis, usually called a bridge, replaces two or more missing teeth and it consists of two or more crowns connected to two or more teeth or implants. The crown or fixed partial prosthesis is typically cemented to the teeth by means of dental adhesive and it may be joined to an implant through dental cement or an abutment with screw.
Crowns can be made from various materials, usually from metal-ceramics or just ceramics with non-metallic cores with the same color as natural teeth such as alumina, lithium disilicate or zirconia.
The manufacturing of a crown for a natural tooth requires the preparation of the tooth through its reduction (between 1 and 2mm) circumferentially (360º) to allow space for the ceramic crown. An impression (mold) is made from the prepared tooth that is then used by the laboratory technician to make and produce the individual crown. While the laboratory technician is fabricating the crown, the patient uses a temporary crown made of reinforced acrylic resin to protect the tooth, maintain the esthetic appearance and occlusion. The final crown is finished with the shape and appearance of a natural tooth, being cemented to the tooth by means of dental adhesive. The cosmetic purpose is to produce a crown as if it was a natural tooth that passes through the gum.