Missing teeth disrupt the facial aesthetics and lead to functional disturbances. The remaining teeth lean toward the empty space, rotate around the longitudinal axis and “protrude” towards the toothless area in the opposite jaw. Toothless areas no longer support the soft structures of the mouth (cheeks, lips), causing “hollow” cheeks, and deep lines between the nose and the corner of the mouth (ageing facial appearance). The relation of the jaws may be disturbed due to the loss of teeth, resulting in pain in the jaw angle.
Due to the above description , missing teeth should be replaced with a fixed or a removable prosthetic solution.
Fixed dental prosthetic works are crowns and bridges, while removable solutions are total and partial dentures.
Crowns are the restorations used for lost dental tissue restoration that imitates the natural teeth in their shape, size and colour. They look like caps glued to the tooth.
Crowns should be made when:
- a large portion of dental tissue is lost due to a fracture or a large caries lesion
- there are large dental fillings and a danger of cracking the remaining dental tissue
- patients are not satisfied with the appearance or position of their teeth
- the teeth have naturally worn down due to ageing (abrasions)
- a tooth has been devitalized (the nerve has been taken out) and reinforced by a FIBRE-GLASS ABUTMENT
A dentist and a dental technician take part in the construction of crowns, and the procedure is as follows:
- After the examination, in agreement with the patients, the therapy plan and the teeth on which the crowns will be made are defined.
- Under local anaesthesia, the teeth are trimmed (their size in all dimensions is reduced).
- A soft dental impression mass is used to make an impression of the trimmed teeth and the teeth of the opposite jaw, which is sent to the dental laboratory.
- Depending on the case and the material for the crowns, the dental technician prepares one or several fittings and, together with the patient and the physician, decides on the crown colour
- The finished crowns are cemented into the patient’s mouth (in the case of crowns, on implants, the prosthetic part starts with the procedure specified under 3)
Depending on the material they are made of, the crowns can be non-metal ceramics and ceramic crowns with a metal and/or zirconium base.
Non-metal ceramic crowns may achieve the ultimate aesthetic results, primarily because of the transparency of the material permeating light rays in almost the same way as the dental tissues. The crown requires very precise tooth preparation and a flawless dental impression, so that the dental technicians can make this type of crown under the microscope.
The classic and our most widely used crown is the metal-ceramic crown, due to its good mechanical and acceptable aesthetic features. The base of the crown is an alloy on which a layer of ceramic is fired. The disadvantage of this crown is observed when receding gums occur and the metal edge becomes visible, and/or an allergy to the alloys is more frequently confirmed.
Zirconium-oxide is the state-of-the-art material used for crowns. The prominent hardness and perfect aesthetic features are the main advantages of the zirconium crown compared to the metal-ceramic crown, along with better thermal insulation of the trimmed teeth and reduced soft tissue irritation. There are no allergic reactions, so it is the material of choice for sensitized persons.
Bridges are fixed dental prostheses consisting of several connected crowns and “bridging” the toothless areas in the jaw. Bridges are created in cases when a patient lacks one or more teeth.
The bridge-making procedure is the same as crown making. The dentist trimming the teeth to be the bridge carriers takes an impression and the dental technician makes a bridge. The bridge carriers can be existing teeth or implants.
After cementing, the patient needs to take care of the appropriate oral hygiene. Apart from a toothbrush and toothpaste, the use of the following is recommended:
- Interdental brushes
- Special floss for cleaning the area between the gums and the body of the bridge
- Electric tool that cleans the areas between the crowns with a water jet (water pick)
The selection of the procedure depends on several factors, primarily the number, order and periodontal status of the remaining teeth, as well as the status of the toothless ridge and the mucosa. Prosthetic solutions on implants and fixed works, if possible, should always prevail.
Advantages of bridges compared to dentures:
- they are bound to the carrier teeth and cannot be taken off or removed from the mouth
- pressure forces created in the course of chewing are transmitted to a tooth (as with natural teeth), and not the surrounding soft tissues
- better aesthetics can be achieved
- there are no parts of the bridge on the palate, below the tongue or any other soft structure
- the functions of speech and chewing are the same as with natural teeth
- the patients adapt quickly
Mobile prostheses, or dentures, are removed from the patient’s mouth. They are divided into complete and partial dentures.
Complete dentures are made when all the teeth in a jaw are missing.
The complete flat dentures are made of acrylate and they can be reinforced with a metal base or mesh, if needed. If there is an allergy to acrylate, then polyan (crystal) dentures should be made, as they do not contain acrylate. Their other features are better than those of plate dentures, and their performance as both complete and partial dentures is excellent.
In the case of complete dentures, the chewing forces are transmitted in a non-physiological manner and implants should be installed, as dentures on implants are the best in terms of physiology, functioning and aesthetics, also providing the best and safest feeling for the patients: they are reduced and because of their connection with the implants, they are firmly in place.
artial dentures compensate for one or more teeth (but not all), and they are made when, for any reason, a fixed prosthesis cannot be made.
Partial flat dentures are made of acrylate and they are regarded as temporary prostheses, as they need to be replaced after a maximum of five years. The chewing force transmission is also non-physiological, as the burden for the existing teeth is not equal and the wire hooks damage the teeth they are adapted to, in terms of caries and dangling teeth. According to their dimensions, they are much bigger and thicker than other types of partial dentures, so the patients take a longer time to get used to them.
This is why partial dentures made of contemporary materials like valplast, bio dentaplast, flexiplast dentures and partial skeletal dentures are more frequent.
There are cases when the order of the teeth or the quality of the remaining teeth makes fixed prostheses, i.e. bridges, impossible, and the patient does not want or is not able to have implants done (an insufficient amount of bone, insufficient space for implant placing,…). With the assessment of a dentist, it is then possible to make so-called combined prostheses, consisting of crowns or bridges and dentures compensating for the toothless part of the jaw.
The dentures themselves usually consist of a metal skeleton and rose acrylate on which the teeth being restored are placed. The connection between the dentures and bridges or crowns may be made with hooks or attachments.
The advantage of the combined work is that the connection between the crowns and the dentures can be made without hooks that disturb the aesthetics of the prostheses, with the attachments representing a kind of internal connection used for connecting instead. The role of the attachments is not only to ensure the stability of the dentures and the equal transmission of chewing pressure, but to improve the aesthetics of the whole prosthesis in general.
A visit to a dentist is necessary before making each dental prosthesis, as the dentist will perform detailed analyses to establish the existing condition of the teeth and the supporting dental apparatus, X-ray diagnostics and photo documentation. Your dentist can only recommend the type of prosthesis that suits you most after all these assessments.
Dentures carried by implants
Cases not meeting the conditions for fixed work on implants do not always need complete dentures made.
If there is a sufficient amount of bone in certain parts of the jaw, complete dentures on the implants can be made. The number of implants required for these complete dentures differs, so in the lower jaw, it may be no less than 2 to 4, whereas in the upper one, there should be no less than 4 implants.
Locators or crossbars are used for the stabilization of the dentures. This is how the dentures are firmly placed on both the upper and the lower jaw and do not move in the course of speaking or lip movement.
The advantage of dentures made on implants is a much greater stability than complete dentures, which the patients particularly feel in the lower jaw. The dentures are also reduced and do not occupy too much space in the patient’s mouth, providing better comfort and perception of taste.