Prosthodontic treatments are performed with great frequency in dental practices.

Being complex procedures to replace or restore missing or damaged teeth, prosthetic work can be made from a variety of materials using a variety of techniques.

Indications for dental crowns

• Teeth with carious or non-carious lesions that can no longer benefit from conservative treatment: filling materials have their limits, so in the case of large destructions, the deficit of substance can no longer be covered to ensure good functional integration and strength.
• Dyschromia: aesthetic defects can be corrected by fitting crowns or prosthetic veneers.
• Malposition: teeth with slight changes in position for which the patient, for various reasons, does not want orthodontic straightening, can be corrected with crowns.

Depending on the objectives of the dental treatment and the patient’s financial possibilities, crowns made in the dental surgery can be non-physiognomic, semi-physiognomic and fully physiognomic.

Semi-physiognomic crowns

As the name suggests, crowns of this type have a metal, non-physiognomic component and an aesthetic component, represented by acrylic, ceramic or composite. The metal portion is only partially covered by the aesthetic portion.

The metal has the following characteristics:

• It can be noble or non-noble alloy.
• Strength: ensures hardness and durability of the prosthetic work over time.
• Biocompatibility: no harm to surrounding tissues.
• Economical: the price of a metal-containing restoration is significantly lower than an all-ceramic one.
• Poor aesthetics: the metal portion can be seen directly in the oral cavity or can show through the thin layer of ceramic veneer.

Semi-physiological crowns are the type of prosthetic work in which the ceramic component only partially covers the metal component, and both are visible in the oral cavity to varying degrees.

Semi-physiological crowns for frontal teeth

Frontal teeth are characterized by 4 surfaces (one buccal, two proximal, one oral) and an incisal edge. In semi-physiognomic work the metal component will be present on the oral portion, slightly visible and on the incisal edge.

Even if the incisal edge is exposed in the speech act, veneering this region with esthetic material will be likely to generate cracks or even fractures of the crown over time. Thus, for strength reasons, the incisal edge will always be made of metal.

Semi-physiological crowns for posterior teeth

The posterior teeth, located distal to the canines, are characterized by 5 surfaces: one buccal, one occlusal, one oral and two proximal.

In prosthetic treatment with semi-vision crowns, the metal component will occupy the occlusal and oral surfaces. Again, the reasons for the occlusal metal coating will be mechanical, strength reasons.

Characteristics of semi-physiological crowns:

• Strength: the metal will slab key areas, susceptible to being subjected to increased forces. Therefore, the risk of microcracks and fractures, characteristic of all-ceramic prosthetic work, is eliminated.
• Poor aesthetics: they are more aesthetic than all-metal crowns but less physiognomic than variants where the ceramic, acrylic or composite component completely covers the metal.
• The risk of detachment of the aesthetic portion is increased.

Semi-physiognomic crowns are a good prosthetic option when a strong, affordable and moderately aesthetic prosthetic restoration is desired.