Nowadays, more and more patients are coming into our office that ask us why we make a full-face veneer (a so-called crown) or a partial veneering ceramic (the so-called facet or dental contact lens).

The question that arises:

Which one is the best?

In response to the above question we can not say that one option is better or worse than the other because both have specific indications and when applied correctly obtains an extraordinary aesthetic result and great durability.

Ceramic facets are indicated on relatively intact teeth, which are slightly altered in color, with spaces between the teeth (so-called diastemas), with spots, which present with cracks, small or moderate caries, atypical shapes.

How to choose between facet and crown treatment?

To make this choice we need to evaluate some important clinical features such as:

– Lingual surfaces of intact teeth – if the lingual surfaces are dentin or decayed, the ceramic facets are not indicated and in these cases we should opt for crowns. We must have lingual surfaces intact to be able to opt for facets.

– Occlusion – patients who have bruxism and great dental wear have no indication to make facets and in these cases we should always opt for crowns.

– High caries activity – the presence of significant or active caries indicates crown placement in the prevalence of ceramics. In patients with a high prevalence of caries the placement of the margins of the slightly subgingival ceramic crowns allows a greater resistance to caries than in the supragingival margins. Ceramic facets are indicated when the cariogenic activity is small.

– Need for occlusal changes – in cases where a change in the vertical dimension of the occlusion is required, or where we require significant occlusal changes, crowns generally offer a more appropriate treatment than facets. Patients need to have a correct and stable occlusion to choose facets.

– Lack of enamel on dental surfaces – When teeth have enamel defects on tooth surfaces we should opt for crowns. For facets to have an effective bonding must have a surface with 50% more of the presence of enamel.

– When the dental surface is more than 50% dentin, crowns are the best treatment option. The lower central and lateral incisors generally have little enamel, making the long-term bonding of the facets questionable.

– Teeth that require a great change of position – teeth that are rotated by norm have an incorrect occlusal relation. Occlusal contact and stability are ideally achieved with crowns.

– Need for orthodontic treatment – in a first analysis we must analyze the need for orthodontic treatment. In cases where there is clear evidence and need for orthodontic treatment this treatment should prevail to the detriment of facets.

– The color parameter can influence the choice of facets or crowns – in case we have adjacent teeth in crowns or facets can define the decision in which type to use. In clinical cases where the aesthetic requirements are high, we will achieve a result of excellence if we opt for crowns because we make a more radical wear the color of the tooth (dental stump) that is underneath the crown will not influence the color of the same.

– Treating a tooth or multiples – any dentist has experienced the difficulty of combining the color of a tooth relative to the adjacent teeth. The crowns block the color of the tooth stump, while with some exceptions, the color of the facets is influenced by the color of the tooth stump. The final color of a facet is related to the remaining structure of the tooth, the cement used and the color of the ceramic. This combination of three colors makes it very difficult to mimic the color of the adjacent teeth.

– Difficulty in cementing facets versus crowns – Most clinicians agree that the procedure for placing a facet is more difficult than the crown procedure. The preparation of facet teeth is generally very simple, but cementing them requires meticulous attention to proper positioning and color, as well as avoiding splitting the facets during cementation. This difference in difficulty led some dentists to charge higher facet rates than for crowns. With experience and repetition, facet placement becomes relatively easy and predictable, and the results can be excellent.

– Type of material to be used – Currently, lithium disilicate is the most popular material in ceramic veneers. From the clinical point of view, the two most relevant parameters when selecting a ceramic system are aesthetics, since most of our ceramic restorations are placed in the anterior sector, and, secondly, the mechanical resistance, since they must be capable of supporting the functional and parafunctional occlusal loads, especially in the posterior sector. Both parameters are closely interrelated because, in order to have a good mechanical behavior, ceramics need to increase the proportion of crystals in their composition, but, in contrast, this higher content of crystals implies a loss of the optical properties of the porcelain becoming more opaque The importance of high flexural strength lies in the fact that feldspathic porcelain does not withstand the slightest bending. That is why it is an important property especially when it comes to rear crowns and bridges.

Considering the mechanical strength, we can classify the current ceramics into three groups: low resistance ceramics (Feldspathic ceramics, and Max Esthetic ceramics), moderate resistance ceramics (lithium disilicate, Max Press / CAD) and high strength ceramics (zirconium oxide).

However, a recent survey conducted by Clinicians Report Foundation shows that the use of feldspathic pottery and ceramics enhanced with leucite (eg IPS Empress) are still popular, however, Zirconia caused a revolution in the profession, and crowns made of zirconia from full outline are more popular than facets. As the aesthetic characteristics of zirconium continue to improve, there is no doubt that zirconium ceramics will be able to conquer the market more and more.

The ceramic facets, when indicated and duly realized, have, technically, aesthetic appearance of excellence during many good years. This is not the case with many metal-ceramic crowns, which often show gingival margin exposure and blackening of the gingival margin due to the release of metal oxides.

Ceramic veneers are fantastic restorations for some patients. Pure ceramic crowns (without metal) are also highly successful restorations.

Making the decision about what is best for specific patients requires consideration of the myriad clinical features discussed in this article. The materials and techniques available today for any type of restoration are the best in the history of aesthetic dental medicine.

The CERO team wishes a great week to all our readers

Dr. Tiago Ribeiro