Restorative
Dentistry

What is Restorative Dentistry?
Historically, Universities have required some type of manual dexterity test for admissions into dental school. These tests usually involve carving a tooth sample using an easy-to-handle material like soap or wax. Once in dental school, dentists spend a great deal of time and effort learning the intricacies of dental anatomy and many dentists are particularly proud of their manual skills. In this context, some creative mind, over the internet, has proposed that the meaning of the word ‘dentist’ can be defined by the combination of three different concepts doctor, engineer, and artist. Restorative dentistry can be described as the pinnacle of this aspect of the dental profession.

Restorative dentistry involves the reconstruction of dental tissue caused by dental caries, chemical and mechanical trauma, and congenital diseases. For a dental procedure to be considered restorative, it has to involve the reconstruction or redesign of teeth that are considered functional, or that have the potential to contribute to the overall oral health of the patient. For instance, congenital diseases can cause teeth to have abnormal shapes. Dentists use restorative dentistry to redesign the anatomy of these teeth and therefore improve masticatory function. In contrast, restorative dentistry should be avoided in cases where teeth must be extracted.

Restorative dentistry is a complex branch of dentistry and currently represents around 50% of the market value of the industry as a whole. It is projected that the market value of this industry will grow to USD 25.9 billion by 2025.

Types of restorative dentistry
Generally speaking, operative dentistry procedures are divided into two wide groups – direct and indirect. Direct procedures, as its name implies, involve the use of materials and techniques that are compatible with the environment of the oral cavity. This means that the dentist can handle the materials and restore lost teeth structure in-situ. Indirect procedures require techniques that can not be performed in the oral cavity and usually involve collaborative work between dentists and dental laboratory technicians. Traditional fillings are a clear example of a direct procedure, whereas a dental crown is a clear example of an indirect technique.

Direct restorative dentistry
Direct restorative treatments are recommended when the structural integrity of the affected teeth has not been compromised. This means that the remaining dental tissue is healthy and strong enough to support the restoration. Dental fillings and composite veneers are the most common treatments in this category. The material of choice depends on multiple factors, including, aesthetic considerations, size of the defect, functional load, and relative location of the defect with the gingival (i.e., gum) margin. For instance, amalgam restorations are structurally stronger than dental composites, but dental composites are more aesthetic. In the case of caries near the gum margin, or the dental root, glass ionomers are the material of choice. Dentists are well trained to evaluate the restorative needs of each specific case. That being said, patients are often presented with a few viable options for their choosing – especially when the material recommended by the dentist is not in line with the patient’s subjective ideas of beauty.

Proper integration between the restorative material and the underlying dental tissue is the most important factor for the long-term success of these restorations. If the dentist fails to achieve this integration, the most common complication has to do with the development of secondary dental caries in the restoration-tooth interface. Patients need to be aware that despite the technical efforts done by the dental professional to make that interface optimal. These interfaces require additional attention during dental hygiene procedures.

Indirect restorative dentistry
Materials used for direct techniques, although different in most characteristics, are similar in the sense that their physical properties change during the course of the clinical intervention. In other words, these materials change from a soft and pliable state to a solid and rigid form. This state change is driven by chemical reactions between the different phases of the compounds. This is relevant because the load resistance for these chemical bonds is lower than the metallic and covalent bonds achievable using indirect methods. For instance, dental veneers can be made using both a direct and an indirect approach – using composite resin and zirconium dioxide respectively. Veneers made with composite resin have a flexural strength of 160 MPa while zirconium dioxide veneers have a flexural strength of over 900 MPa. Furthermore, indirect restorative materials can be polished more adequately and therefore are less prone to discolorations with time. Crowns, veneers, bridges, and inlay and onlay restorations are the main examples of this category of treatments.

One disadvantage of indirect restorations has to do with the need for multiple visits to the dental office. This is because the work that needs to be done in the dental laboratory is usually time-consuming. Digital dentistry has been used in this field to expedite the manufacturing process. Many dental clinics are now equipped with a suite of digital-enabled tools that allows the manufacturing of these restorations in the dental clinic instead of the laboratory.

Cosmetic dentistry and ethical concerns
All restorative procedures are influenced by aesthetic concerns. For example, amalgams are never used to restore anterior teeth. Cosmetic dentistry differs from restorative dentistry because in this case treatment is based on aesthetic reasons only. Of course, there are some ethical issues and concerns with this type of elective procedure. Especially if the dentist acts in a more entrepreneurial-driven way instead of a healthcare-driven way. If that happens the patient is the one who pays a big biological price. On the other hand, some dentists argue that the phycological and sociological concerns that patients have are as valid as their functional physiological needs. In any case, the patient needs to make decisions under the umbrella of ethically sound informed concern.

Conclusion
Both types of restorative dentistry, direct and indirect, are fascinating fields in modern practice. Resin composites keep improving and becoming more durable and aesthetic. Crowns and bridges now can be manufactured in one clinical appointment thanks to the use of digital workflows and Computer Assisted Manufacturing. Dentists need to balance their urge to use and enhance their practices with these ‘new’ exciting technologies, by remembering that the best dentistry is the dentistry that is never needed.