Crowns for front teeth: which ones are better to put and why

The incisors and canines make up the smile line, any damage or defect in this area is immediately noticeable. The restoration and reconstruction of the anterior group of teeth is the most complex process of all clinical options. When replacing the supragingival part of the tooth with an artificial crown, it is necessary to achieve a harmonious combination with the adjacent units, soft tissues. The best crowns for the front teeth should have a natural shade and degree of transparency, like the real incisors. At the same time to be not only beautiful, but also strong enough.

Orthopedic dentistry uses different methods, technologies and materials to restore the frontal group of teeth. What crowns to put on the front teeth, what method of prosthetics to choose – the doctor decides based on the clinical situation. The patient is offered several treatment options, from which he chooses the optimal one in terms of aesthetics and cost. The physical and optical properties of restorative materials are well studied today, which makes the choice much easier. A comprehensive approach to treatment makes it possible to create prosthetic structures with individual optical characteristics, achieving the best aesthetic result.

Indications for prosthetics

Chipped crown (when the defect cannot be corrected by placing a filling);
multiple cracks in the enamel;
pathological abrasion of enamel;
fluorosis;
tetracycline teeth;
discoloration (darkening, yellowing);
destruction of the supragingival part of the tooth more than 70% with preservation of the root;
thin, weakened enamel;
replacement of an old restoration.

Prosthetic options depending on the clinical picture

If you need to correct the shape, size, color of incisors, canines, eliminate cracks, small chips, a good solution – ceramic or zirconium veneers. Thin dental onlays (up to 0.3 mm) require minor preparation of the enamel layer. They are fixed to the outside of the teeth with composite adhesive (bond).
In case of volumetric destruction of the supragingival part(more than 60%), a dental crown is placed. Before installation, the incisor, canine is given the desired shape (shaped), the root is strengthened with a stump inlay (if necessary), the prosthesis is fixed on the support with dental cement.
If not only the supragingival part, but also the root is destroyed, implantation will help to restore full aesthetics and functionality of the tooth row. If the clinical situation allows, the implant is immediately loaded with a temporary crown, which is replaced with a permanent crown after the artificial root has taken root.

Immediate prosthetics for single defects is possible only for incisors, canines (up to 5 premolars). The prosthetic structure is removed from the bite (made slightly lower in height). This is necessary to eliminate the risk of loosening the implant due to the load on the denture.

What crowns are placed on the front teeth

The front incisors are not used in chewing food, so in prosthetics of this group of teeth there are more requirements for aesthetics, restoration of correct occlusion. But the material of the prosthesis must be strong enough to withstand the load of biting. To create crowns, metal alloys, metal-ceramics, ceramics (porcelain), zirconium oxide, E-max metal-free ceramics, plastics, etc. are used. The material determines the cost, appearance, durability of the restoration.

Types of crowns for front teeth

Metal crowns

Created from metal alloys, including precious ones, by casting or stamping. The high strength of metal provides long service without the risk of cracking, chipping. Crowns made of gold are easily molded, reproduce in detail the anatomical shape of the tooth. Metal alloy constructions are inexpensive (except for crowns made of gold), comfortable, strong, durable, but do not resemble natural teeth, so they are not suitable for prosthetics of the smile area.

Metal-ceramic

Metal-ceramic crowns for front teeth are one of the popular prosthetics options due to their low cost (except for gold, palladium, and platinum restorations). They have a strong metal base, on which a ceramic mass identical in color to natural enamel is applied layer by layer. The one-piece casting method minimizes the risk of complications because there is no gap between the inside of the denture and the support.

Facing is performed layer by layer – each subsequent layer is subjected to heat (baking) to achieve the highest adhesion between metal and ceramic. The fabrication technology makes it possible to achieve a natural appearance of the prosthesis. But this aesthetics is not enough to make an incisor or canine look natural.

Living teeth are capable of reflecting, transmitting, scattering light. The metal base does not have this property – when natural light hits the tooth row, the difference between natural and artificial crowns is noticeable (the base shines through the coating). Another unaesthetic disadvantage – discoloration, lowering of the gum around the base of the crown (gray neck). The reason – oxidation of metal due to prolonged contact with the mucosa. Also among the main disadvantages – accelerated abrasion of the enamel of the antagonist tooth, chipping of the ceramic veneer, allergy to metal.

^{The metal base of the metal-ceramic crown slightly shines through the gum}

Modern orthopedics offers a more aesthetic result – metal-ceramic crowns for front teeth with a shoulder mass. In such constructions there is no open metal ledge – they are completely covered with a ceramic veneer. Metal does not contact the mucosa, which eliminates the bruising of the gum around the prosthesis. But the manufacturing technology of such models is more complex, which affects the cost of restorations.

Ceramics

Ceramic crowns for front teeth are made of dental porcelain by firing or casting. Due to the optical properties of the material, all-ceramic structures look identical to living teeth. They are biocompatible, do not stain, do not oxidize, and last 7-10 years.

Porcelain prostheses are light, thin, and do not require deep preparation of the supporting units. The disadvantages of such restorations include:

higher cost than metal-ceramic constructions;
brittleness of the material (porcelain cracks and crumbles under heavy loading);
impossibility of bridge prosthetics.

In case of severe destruction of the crown part (if only the root is left), the installation of crowns on the front teeth involves the use of metal-free inlays or posts. Metal structures are not used because they will shine through the ceramic and can crack the restoration. All-ceramics are only bonded to the tooth itself.

E-max ceramics

Today, metal-free solutions designed according to the latest advances in robotics have come to the forefront. E-max glass-ceramics based on lithium disilicate is devoid of all the disadvantages of dental porcelain and allows you to create beautiful, incredibly strong prosthetic systems. The manufacturer offers blanks of five different levels of transparency, which when making a crown provides a smooth color transition from the gingival part to the incisal edge, achieving a natural-looking restoration.

Advantages of glass-ceramic:

Leucid ceramics is very strong, wear-resistant, and suitable for restorations of frontal, chewing units. It recreates in detail the structure of natural enamel, relief.
Depending on the method of fabrication, E-max crowns can be pressed (E-max PRESS) or milled (E-max CAD).
3D CAD/CAM milling is automated, allowing for thin, lightweight, durable restorations that are indistinguishable from living teeth.

The only disadvantage (and that is relative) is cost. Frontal crowns E-max are more expensive than metal-ceramic or porcelain analogs. But this disadvantage is compensated for by the high strength, natural look, inertness of the restoration, and durability. The average service time is 15-20 years. They are inferior in durability only to zirconia prosthetic systems.

Emax is used for single restorations, as part of bridges for the front 4 teeth. Pressed models are not suitable for bruxism. Excessive mechanical loading is fraught with breakage of the restoration. In such situations, only milled designs are suitable.

Zirconium dioxide

Zirconia crowns for anterior teeth are made automatically by milling on a computer-controlled machine. The ultra-strong, bioinert, hypoallergenic material allows the creation of thin, lightweight restorations for any part of the jaw. CADCAM products are up to 0.4 mm thick. This minimizes trauma to the dental tissues during preparation. Thanks to optical properties close to natural enamel, a smooth emergence of the crown from the gingiva is ensured – the color of the restoration is intense in the center and more transparent at the incisal edge.

Zirconia restorations are stronger than all other restorations, including metal-ceramics, which allows them to be used in bridges of any length. Since zirconium has a snow-white color, crowns for the frontal area are made with a ceramic lining, providing the artificial tooth with a natural look. The exception is Prettau zirconium materials, which are colored with special liquid dyes, allowing to do without layer-by-layer application of ceramics.

The cost of zirconium prosthetics is 1.5-2 times higher than metal-ceramics. But the service life of zirconium restorations is 20-25 years and longer, which compensates for the price.

Plastic dentures

Plastic crowns are placed on the front teeth as temporary, protective restorations. The patient wears them while the permanent structures are being fabricated. The advantages of plastic constructions are ease of fabrication, low price. But the disadvantages of such restorations are more – allergies, gingival inflammation, rapid loss of aesthetics (the prosthesis absorbs foreign odors, dye pigments), fragility, short service life. Although the declared service life of plastic models is up to 2 years, after 1-2 months their aesthetic condition deteriorates significantly.

Stages of prosthetics

Preparation – assess the general condition of the oral cavity, take an X-ray, perform hygienic cleaning (removal of plaque, calculus), treat tooth decay, gums, change old fillings.
Preparation – the front tooth under the crown is trimmed, give the stump the desired shape. If indicated, depulpation, treatment, filling of dental canals are carried out. In case of severe destruction of the supragingival part, the root is strengthened with a stump inlay. The prepared support is closed with a temporary plastic construction to protect tissues from destruction, chemical and temperature irritants.
Making impressions – the doctor takes impressionsof the patient’s teeth using an impression spoon with impression mass or a digital scanner. The obtained data is transferred to the dental laboratory.
Crown fabrication – based on the models, the laboratory creates a prosthetic system by casting, pressing, milling. At the stage of manufacturing, the model is tried on the patient, if necessary, adjustments are made.
Installation – the finished crown is fixed on the support with dental cement. The crown on the implant of the front tooth is installed by cement or screw method.

How to choose

Prosthetic dentistry presents a wide range of materials for prosthetics. What crowns on the front teeth to put the patient chooses based on their cost, reliability, durability, appearance. For the restoration of the frontal zone, the best materials are aesthetic ceramics, glass-ceramic E-max or zirconium oxide with gradient coloring. From the options offered by the dentist, the patient will choose the one that is suitable in terms of appearance, price, and durability.

For installation on implants or for bruxism, zirconium models are preferred. Crowns on the upper front teeth with support on implants are fixed on zirconium abutments. Titanium abutments in this area will show through the thin restoration, reducing aesthetics.