Dental services

Crown and bridge solutions

Why is it important to replace teeth?

Aesthetics is only one of the many reasons. Gaps in the denture - or even one missing tooth - may negatively affect your bite so if the replacement does not take place, the tooth opposite the gap will gradually grow out of the line and the neighbouring teeth will lean in the empty space. If several teeth are missing, the remaining ones get overburdened. As a result, you may lose more teeth in the near future. After some time the bone around the missing teeth becomes sparser and starts to decay, which later makes the possible tooth implantation more difficult. Food remnants may deposit in the hole that remains after the extracted tooth, which may lead to further tooth decay and gum diseases, but even the mandibular joint may damage due to the long-lasting dysfunction.

About removable dentures in general

Removable dentures are such prosthetic devices that the patient can remove himself without any medical assistance. This is important because the maintenance of oral hygiene is only possible with the everyday thorough cleaning of the denture and the oral cavity - and we cannot see our dentist every day, can we?
Nowadays removable dentures are hardly noticeable but the patients need to get accustomed to wearing them, which may take days or even weeks for the more sensitive.

What are dentures made from?

Dentures are custom-made in the dental laboratory, based on the dental imprints. The base is gum-coloured plastic, which is attached on the gum. The upper denture partly or completely covers the palate, while the lower denture is horse-shoe shaped. The frame of the denture may also contain a metal net. The false teeth are generally made from plastic and harmonise with the colour of natural teeth, which is especially important in case of partial dentures.

Complete removable denture

A complete denture is made for a patient with no teeth left. The complete denture substitutes all the teeth on the upper and/or the lower mandible. This solution is applied if restoration is not possible in any other way, for any reason. The denture is fastened using the anatomic conditions of the mandibles, the suction effect of the palate, the bite pressure and, in case of the lower denture, gravity. In case of the lower denture, due to the unfavourable anatomic conditions of many patients, it may be difficult to prepare a perfectly stable denture but as few as two implants can solve the problem and stabilise the denture.
The material of the complete denture may be hard acrilate or flexible plastic. Wearing the denture may cause significant feeling of discomfort at the beginning as it occupies somewhat more space in the mouth than natural teeth but this bad feeling disappears after some time - days or weeks.

Maintenance of the removable denture

The denture has to be removed for cleaning. Use a toothbrush (perhaps with hard bristles) and tooth-paste but do not forget about the cleaning solution, which will loosen the plaque and disinfect the denture. You may have to use different cleaning liquid for metal-based dentures. However, you have to know that it is not the right solution to keep the denture in a glass all night long, as it is often depicted in films and jokes. Apart from the minutes of cleaning - and any possible repair or relining - the removable denture is to be worn permanently.

Does the denture affect appearance, chewing/eating and speech?

A new denture may be uncomfortable in the first few weeks. The unusual feeling (wobbling feeling and the sensation that some large, foreign object is in the mouth) caused by the denture is not rare until the facial muscles and the tongue learn how to keep the denture in its place. It only slightly affects appearance, what is more, it will probably improve it, making your face and smile more attractive.
At the beginning even eating requires practicing. Chew slowly and use both sides of your mouth at the same time to prevent the denture from wobbling. Start with food that is easy to chew and then you can gradually return to your usual eating habits. The new denture will also affect your speech at the beginning. The dentures may slip or move when you are smiling, coughing or laughing. If this happens, you can return the denture to its proper position by swallowing a bit and closing your mouth. You will also have to learn how to wear the denture properly.

What is a partial (combined) denture?

The combination of removable and fixed tooth replacements is called combined denture. The removable part is sometimes not visible at all. In other cases, for example when a partial removable denture is anchored with clasps, possibly a retaining crown or telescope ring system is applied, it is fitted with a special fastening technology.
In case of partial dentures, there are a few teeth left in the mouth (but their position and/or number or bad stability due to periodontal disease do not make it possible to apply a fixed denture), which can largely improve the stability of the denture. The material of the denture may be pure plastic or a combination of plastic and metal. Both types are fitted with fixing clasps that hold the denture in position. These clasps are hardly visible but, depending on their position, they may show when the patient smiles or opens up his mouth. Their advantage is that the denture is thin and the size of the base plate can be reduced so it takes shorter to get used to the denture, which will disturb tasting less.
As dental implantation has become a routine treatment, the preparation of such dentures has become less common recently.

What is the difference between plastic partial dentures and those containing metal?

Plastic partial dentures are cheaper but in the long run the fastening clasps may damage the healthy teeth that hold them.
Partial dentures made of metal are much stronger because they contain the alloy of chromium and cobalt and other metals. They are also more comfortable to wear. The frame is metal, which is covered with plastic in the same colour as the gum and the natural-coloured teeth are attached to this. The only disadvantage is the price as metal partial dentures are somewhat more expensive than those containing only plastic.

Crowns and bridges

If the crown of the tooth is so damaged that it cannot be restored using conservative dental methods - aesthetic filling or inlay - then the preparation of a crown may be the solution.
For this purpose the dentist files the tooth to obtain a conical shape, makes an imprint of the prepared tooth stump, based on which the dental technician prepares the crown. The complete prosthesis covers the part of the tooth within the oral cavity like a cap. The lifetime of crowns is at least 8 years but in most cases they last for decades.

Preparation and attachment of the crown

If a crown is needed and the tooth is seriously decayed, there is a risk of infection, or, perhaps, the pulp (the innermost part of the tooth) has been injured, root treatment may be necessary. Naturally, not everyone who is to receive a crown needs root treatment.
If someone does get a crown a crown following root treatment and the original tooth is in such a bad condition that it cannot hold the crown, the dentist will place a supportive root pin into the tooth. The root pin may be made of prefabricated rust-free steel, gold, titanium or fibre optic raw material, which the dentist can place directly into the root canal but it is also possible to prepare an individual root pin, made by the dental technician based on an imprint, so that the pin will better fit the shape of the prepared root canal. The latter is a stronger and more durable solution. The root pin is placed and bonded into the root canal and thus the tooth becomes capable of holding the crown.

In case the crown is fixed without a root pin, the dentist simply files the outer surface of the tooth to receive a cone-like shape. Then he takes an imprint of the tooth and another one of the opposite mandible to determine how high the crown should be so that it will perfectly fit when the patient bites. The material of the imprint hardens within 3-4 minutes when it can be removed. The imprints are then sent to the laboratory along with the chosen colour. And any further information needed. Then the patient receives a temporary crown, if required, for the few hours or days while the final crown is made. Temporary crowns are made of plastic in the dental surgery or the dental laboratory, immediately. They are not durable. The temporary crown is removed on the next occasion and the final crown is tried on. Sometimes further shaping or polishing may be necessary before the crown is permanently bonded in its place. If the crown is ready, it is bonded on the root stump.

The above-mentioned procedure means that the patient has to see the dentist two or three times before the crown is ready. First the preparations are made, the imprints are taken, the colour is chosen and the temporary crown is fixed. On the second and third occasions the final crown is tried and then bonded. All this takes place totally painlessly, either due to the local anaesthesia or the preceding root treatment. If there is no nerve left in the tooth, no local anaesthesia is needed.

What are crowns made from?

They can be made entirely from metal, ceramics with a metal basis, ceramics with a precious metal basis, pure ceramics or porcelain burnt on a zirconium-oxide frame, possibly composite (the latter is less fragile than crowns made from pure porcelain). In case of metals, gold alloy or other alloys (palladium, nickel or chromium, titanium) are used. Metal-based porcelain and pure ceramic crowns look like healthy natural teeth. Pure ceramic teeth are made without using metal, they are strong and their appearance is identical with porcelain crowns, so they can be used in any part of the mouth. In the case of complete bridges, however, the solution with no metal frame may not have the necessary bearing capacity. Crowns without a metal frame, especially pure porcelain crowns, can only be used as single crowns. Strengthened with optical fibre, composite crowns can form three-piece bridges and zirconium can be the material of bridge frames of several crowns.

Types of crowns according to the material

Biceramo-metallic crown: This crown is commonly called a porcelain crown in everyday language, although it is built on a special metal so it is not purely made from porcelain. The colour of the concealing ceramic is chosen using the so-called shade guide in order to match the other teeth and the patient's requirements. The porcelain completely covers the metal. These prosthetic devices are long-lived and aesthetically immaculate. The long lifetime is ensured by the quality of the concealing material and the metal frame. The metal frame may contain different materials.
Galvanic gold crown: the frame, the part under the concealing material, is prepared using the method of galvanising, which ensures extreme accuracy.
Galvanic zirconium, crown: this frame is also made using the galvanising method but the material of this frame is zirconium, i.e. it is metal-free. Accuracy is also outstanding.
Metal-free ceramic crown (jacket crown): perhaps the most perfect crown type but it can only be used as a solo crown (no bridge can be made of it) and it is really expensive. It meets the highest aesthetic requirements.
Zircon-ceramic (zirconium-oxide ceramic) crown: the ceramic crowns burnt on a zirconium-oxide frame have excellent aesthetic value and they are strong, too.

Crowns and bridges built on implants: they only differ from bridges and crowns built on teeth in their technology, not in their appearance. They can be fixed by gluing or screwing.

How should I take care of my denture?

Just like any other tooth: you should wash even the areas under the bridge every day in order to avoid bad mouth odour and periodontal diseases. In addition to the normal toothbrush, you can also use a special toothbrush and tooth floss.
The denture needs to be removed for cleaning. Use a toothbrush and tooth-paste but do not forget about the cleaning solution. You may have to use a different cleaning liquid for metal-based dentures. However, you have to know that it is not a good solution to keep the denture in a glass all night long as it is depicted in many films and jokes. Removable dentures are to be worn permanently, apart from the minutes of cleaning and any possible repair or relining.

Veneer

We mostly visit our dentist when we suffer from severe tooth-ache or when our front teeth are visibly and aesthetically damaged. The latter may be a result of enamel defect, development anomaly, wide gaps between the teeth (diastema), discolour, discolour following root treatment, incisors broken in an accident, etc. Using veneers, it is possible to largely change the colour and shape of the front teeth, as well as the size of the gaps between the teeth. Their advantage is, among other things, that the treatment requires only minor loss of tooth material; only a thin layer (equal to the thickness of the veneer) needs to be filed off the front of the tooth (generally 0.5 - 1 - 1.5 mm) and, in case of indirect veneer, the same amount off the edge of the tooth.
Regarding the preparation and placement of veneers, there are two different technologies: direct and indirect veneers.
Direct veneers are prepared by the dentist using special filling materials developed for this purpose.
Indirect veneers, prepared by the dental laboratory based on the imprint the dentist took, are bonded on the tooth using adhesive. Applying veneers, it is possible to completely restore the aesthetics of nice teeth; teeth can be transformed to the required shape and shade without having to apply crowns. The surface and colour of the veneer do not change through the years and no deposits build up, due to the hardness and solidity of the material. As no metal is used, they can be applied in case of patients with metal allergies.

When is it recommended?

Veneers are mainly used in the area of front teeth, in case of positioning anomalies, problems resulting from development disorders, discoloured teeth and accidental injuries.
If a tooth has discoloured due to improper root treatment, a metal- or zirconium-free veneer is not recommended as the discoloured tooth would still be visible through the thin layer. In this case the dentist first has to check if the root treatment was performed correctly and then the tooth has to be bleached using an internal whitening process.

When is it not recommended?

Veneers are not recommended if the frontal teeth are seriously decayed, if they have too large fillings or if the patient's oral hygiene is bad, in case of irregular biting patterns (overlap, frontal crossbite) or bruxism (clenching).

Jacket crown

A jacket crown is a metal-free prosthetic device to restore frontal teeth. Its extremely advantageous characteristic is that using this method it is possible to make totally lifelike dentures with the same appearance and colour as the natural teeth. The disadvantage of applying jacket crowns is that a large amount of material needs to be filed off the tooth during preparation, therefore this technology is only recommended for the upper incisors.

Crowns and bridges made with CAD/CAM technology (from zirconium)

Today the preparation of up-to-date, aesthetic dentures is unthinkable without metal-free technology. In this case metal is substituted with a special material, zirconium-oxide (ZrO2), which constitutes the frame of the denture. (This ceramic has been used to prepare artificial hip replacements for over 20 years). When preparing the zirconium crown or bridge, the dentist applies local anaesthetics, prepares (files) the teeth and then takes imprints of them. The data of the sample made based on the imprints are scanned by a special scanner in the dental laboratory, forwarded to the international or Hungarian production centre via the Internet and there a computer-controlled special lathing robot carves the frame of the denture with the accuracy of microns, eliminating the human errors (this is the CAD/CAM technology). The porcelain veneer of the appropriate colour and shape is then placed on this frame in Hungary.
The perfect aesthetic effect is the result of the fact that the frame and the veneer built on it have the same colour. Not only zirconium frames are made using the CAD/CAM technology; it also makes it possible to process traditional metals. Today there are some CAD/CAM laboratories manufacturing zirconium frames in Hungary.

Advantages of the metal-free (zirconium) crown

It is completely metal-free so it can be used without the risk of metal allergy.
The ceramic frame is stronger than metals, still it has the colour of teeth with optimal transparency.
The porcelain veneer perfectly mimes natural enamel.
It is natural with maximum aesthetic effect.
There are no grey gum edges.
Thanks to the strong frame, bridges of several pieces can be built.
As a result of the computerised technology, it is extremely precise and accurate.
It does not trigger gingivitis or gingival recession.
Microscopically accurate closing by the edges.

Disadvantages

It is a more expensive solution than traditional dentures with metal frames.

Dentures made without filing, using computerised technology:

in-lay, on-lay, overlay According to the traditional dental treatment, if two or three teeth are missing, the neighbouring teeth are filed to bear crowns and then the empty space is spanned with a three- or four-piece bridge. In case the teeth neighbouring the empty space, the so-called pillar teeth, are in bad condition, this solution is perfect as it will not only replace the missing teeth but also protect and restore the deteriorated pillar teeth. In case of healthy or slightly damaged teeth, however, the traditional technology requires too much healthy tooth material as the healthy enamel layer has to be removed from around the pillar teeth. In case of a slightly decayed tooth or one with a small filling, this seems unnecessary loss of tooth material.
In order to eliminate the above problem, so-called inlay anchorage bridges, or dentures without grinding, were developed. Instead of grinding off the enamel of the pillar teeth, a special cavity is prepared by cleaning and transforming the minor cavity or filling in the tooth. Such a cassette has to be prepared in both the tooth before and the one behind the missing teeth. The final bridge is bonded into these cassettes, which will substitute the missing teeth and aesthetically fill the prepared cassettes, which were originally decayed cavities.