In modern dentistry there is a large selection of different types of materials for fixed dental structures: crowns and bridges on teeth and implants. This makes it possible to cover the various specific characteristics of the human body, as well as the requirements of patients.
Modern materials have different characteristics and their choice depends on the following factors:
- Aesthetic requirements – anterior or posterior teeth, whether it is a combination with other natural teeth and achieving natural aesthetics.
- Characteristics of the tooth – whether it has changed color and what is the reason for this, whether changes in the structure and shape of the tooth should be masked.
- Characteristics and strength of the gums – in case of gum changes and periodontal problems, in case of need to place a crown or bridge on a natural tooth, gum-friendly constructions are chosen, lighter, with the possibility of better hygiene.
- Amount of tooth structute, that must be removed – different types of materials have different thicknesses. It can vary from 0.2-3 mm to 2 mm. The thicker the structure, the more tooth structure is removed. This is of great importance especially for vital teeth, because of a risk of devitalization of the tooth. In non-vital teeth, this is also important, as they often have less natural tooth structure left, which when destroyed can lead to tooth cracks and damage, even if it has a crown.
- Allergies – The most common allergies are to metals, especially nickel. Fortunately, modern metal alloys are chromium-cobalt, to which allergies are less common. Nickel is almost completely removed, but not completely gone from the market. It is good to keep in mind that in case of allergies to metals, it is good to do a test to see which metals the patient is allergic to, and if necessary, to move to metal-free structures.
- Coloring of the gums – in modern dentistry is rare, but still we happen to observe “graying” of the gums when wearing metal crowns or metal-ceramic crowns. This is quite common in patients with stomach problems, reflux and others that lead to increased acidity in the mouth, which affects the structure of the metal alloy from which the construction is made. Despite the fact that modern metal alloys are well made, there are no unnecessary metal elements, they are printed on modern printers, it is not bad to keep in mind that under certain conditions such graying can be observed.
All of the above factors make choosing a design for your crown or bridge difficult. Always discuss with your dentist which type is best for you, as not every tooth is suitable for every construction. At Avi Dent, we explain to patients everything about the constructions according to their situation, so that they can make the best, cost-effective and long-term choice in an informed way.
Types of constructions
1.Plastic – It is manual, composite, printed, single-layer, three-layer, PEEK. Plastic constructions are most often used for temporary ones. There are different types, which mainly differ in aesthetics and strength in a small percentage. Most temporary structures are not recommended to be worn for more than 6 to 12 months, depending on the type. Printed plastic constructions can be worn longer, depending on the treatment plan and needs. They are not recommended for permanent use, because plastic is a porous material that retains and absorbs plaque, odors and stains, which causes inflammation and irritation of the gums.
Printed and composite layerd temporary crowns
Temporary constructions of the upper and lower jaw
2. Metal and metal with plastic or composite (blend) – Pure metal structures or those with plastic layer only on the visible part of the structure. Plastic in the 21st century has been replaced by composite materials, which make them a little more aesthetic, as far as it is possible to talk about aesthetics in this type of constructions.
Pros
-low amount of tooth structure to be removed – modern metal alloys with a thickness of 0.3-0.4 mm are strong enough and withstand the masticatory forces
-low cost – these constructions are the most affordable
Cons
-poor aesthetics – the metal is visible and although they are partially covered with plastic, they do not copy the natural structures of the teeth well enough
-possibility of allergies – allergies to metals are common, except for pure gold constructions
-possibility to break off the plastic layer, if it is a blend, as it is mechanically attached to the metal and especially when chewed it can break, peel or fall
3. Metal-ceramics and gold-ceramics – aesthetic constructions in which there is a metal part that serves as a “skeleton”. Paint (opaquer) is applied on it, which aims to hide the metal reflections. The top layer are different types of ceramic masses, which aim to give the structure a natural look. The strength of these structures depends on the type of ceramic used to cover the metal.
Gold ceramics
Pros
-good aesthetic construction
-a more budget price compared to pure ceramics or zirconium
-good strength
Cons
-slightly lower aesthetics compared to ceramics and zirconia, due to the metal skeleton, which does not transmit light. This makes the structures a little denser in color and more difficult to play with light. For this reason, they are not preferred to work in the smile zone, especially with available natural teeth that need to be combined аestethicaly.
-more amount of the tooth structure to be removed – in order to have enough space for ceramics and aesthetics, usually the volume of thooth removed is about – 0.8 – 1.5 mm. Good choice for devitalised teeth.
-opportunity for the so-called graying of the gums due to the metal skeleton (reasons mentioned above)
4. BioHPP and PEEK – biopolymer or organic colorless thermoplastic material with good qualities. It is used in medicine for joints, spinal implants and others. In dentistry he finds application in the manufacture of light constructions that spare the gums, in the loading of implants, the manufacture of immediate structures on implants, as well as long-term temporary solutions.
Pros
-flexibility and elasticity – close to that of bone
-lightness – a bridge of 14 teeth weighs about 40 grams compared to 120-150 grams of metal-ceramic
-resistance to breakage
-bio tolerable
-metal free structure, therefore they are no possibility of allergies and corossion
-low absorption of water, which makes it difficult to accumulate plaque
-Excellent for people with allergies
Cons
-narrow application, not suitable for all cases
-the biopolymer skeleton and the composite masses covering it require maintenance over time
-on natural teeth and especially single constructions, are not the first choice due to the amount of tooth structure that need to be removed
5. Pure zirconium – most simply, zirconium is a ceramic reinforced with zirconium oxide. Monolithic material, which gives exceptional strength even at small thicknesses. It is suitable for all types of situations. It is used more often for posterior teeth due to the fact that pure zirconium has no significant optical properties, no transparency. For this reason, in order to play better with light and better aesthetics, zirconium is covered with ceramic masses (listed below). However, modern ways of coloring zirconium bring the aesthetic qualities to a high degree, which makes it preferred for smile zone.
Pros
-metal-free construction, there are no risks of graying gums or allergies to metal
-good attitude towards pink aesthetics and gums
-can be produced in 0.3 mm thick, which saves tooth structurе
-easy maintenance and difficult plaque buildup
-excellent for people with allergies
Cons
-despite its strength in low thickness, it is not a suitable for veneers
6. Zirconia ceramics – when we want better aesthetics, beautiful shades, transparency and a level close to natural teeth – zirconium covered with ceramics is an excellent choice. The construction is similar to metal-ceramics, but instead of metal, there is a zirconium skeleton, which makes this construction strong and aesthetic. The zirconium skeleton can be transparent, translucent and opaque, which allows to cover with solutions many different situations and teeth.
Pros
-high aesthetics
-metal-free construction, there are no risks of graying gums or allergies to metal
-good attitude towards pink aesthetics and gums
-easy maintenance and difficult plaque buildup
-excellent for people with allergies
-appropriate solution for almost any situation
Cons
-not a suitable solution for veneers
8. Pure ceramics and press ceramics – these designs are used for various solutions that require high aesthetics. Because they are slightly weaker in strength than zirconium structures, the protocol for laying, bonding and cementing here is more complicated. Well executed, this is one of the best choices when working in the smile area and when you need micro-invasive structures such as veneers and inlays and onlays. They have good optical properties, close to those of natural teeth, even in very small thickness.
Veneers
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Press ceramics (Emax) inlay
Pros
-microinvasive
-very high aesthetics and good optical qualities
-metal-free construction, there are no risks of graying gums or allergies to metal
-good attitude towards pink aesthetics and gums
Cons
-weaker in strength than zirconium structures
-transparency, which is a minus, when the tooth underneath does not look good aesthetically
-complex cementation protocol
* The set degrees are the maximum that can be achieved with this design in perfect conditions.
* The table is for a rough summary of the different types of materials. Aesthetics and thickness are their values, which depend on many factors.