Sculpting in Dentistry – Requirements, Methods and Limitations in Aesthetic Dentistry: A Minireview

The skill of sculpting is an interesting and important part of restorative and esthetic dentistry. This review article will help achieve an understanding on what we know about this art, the hurdles we have faced, advances achieved, the limitations we still face and would help to gain knowledge and information on how to further advance in the art of manipulation and sculpting of dental restorations. This article aimed to review available literature on manipulation techniques, to summarize the importance of sculpting and to identify methods to face the current limitations of the art.


INTRODUCTION
In the past tooth colored restorations were considered to be lacking in biomechanical properties and strength, thus affecting longevity of the restoration. The materials such as dental amalgam were proved to possess superior physico-mechanical properties and although these restorations necessitated less conservation of natural tooth structure to achieve a mechanical bond, there were far too many limitations when it came to resin based materials, that people and clinicians' preferred to not consider esthetics as a primary component of treatment planning. But over the years we have observed a great change in this practice with the advent of patient awareness about esthetic restorations and the intensive research being undertaken in the tooth colored restorative materials. The disadvantages such as polymerization shrinkage, poor chemical bond strength, staining of restorations, larger particle size and even the complex and highly technique sensitive manipulation and restorative techniques have all seen intensive development.
Research has today proven that resin based cements and other tooth colored restorative materials to be as competent if not even superior to most restorative materials used priorly, in not just material aspects, but overall, thus marking esthetics in today's dental restorative sciences a priority [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Esthetic dentistry is a science requiring precession in order to provide the best possible results to a person. Today, with preventive dentistry gaining momentum and the decrease in caries prevalence, the focus has shifted toward dental esthetics [3]. For this reason, the field is ever growing in scope and must be aided by proper knowledge and understanding of each procedure involved in achieving such perfection is required. In recent years, the information available on esthetic dentistry and also an enhanced awareness of beauty and esthetics is making both patients and clinicians very aware of the skills required to achieve such results. This article reviews the known importance that sculpting plays in esthetic dentistry and to discuss the limitations in manipulation and sculpting of restorative materials. It would also act as a tool to identify possible methods to overcome such limitations in the future, for the betterment of dental precision.

MATERIALS AND METHODS
The search was carried out on electronic databases, including PubMed, Google Scholar, Science Direct reference of literature within the last 15 years.
After conducting an advanced PubMed search using MeSH terms such as aesthetic dentistry, composite veneers, tooth carving and Optical coherence Tomography (OCT) in dentistry, plastic phase in dentistry over the last 15 years the number of results were 3,745; 1,111; 43; 7 and 907 respectively. By conducting an advanced search on Google scholar by filtering results pertaining to the past 15 years, esthetic dentistry provided 5,780 search results, composite veneers provided 2,060 results, tooth carving provided 205 results and OCT in dentistry provided 3,560 search results. By conducting an advanced search on Science Direct for results pertaining to the past 15 years, the results were as follows: Esthetic dentistry-11,064 articles of which 6,370 were research articles and 1,095 were review articles. Composite Veneers -4843 articles of which 3071 were research articles and 366 were review articles. Dental composite techniques -12,832 articles of which 12,255 were research articles and 262 were review articles. Tooth carving -405 articles of which 213 were research articles and 24 were review articles. OCT in dentistry -83 articles of which 31 were research articles and 11 were review articles.
The articles that have been referred to in this article have been done so on the basis of relevance to the topic which will provide a clear understanding into the aim of this paper.

REVIEW
Dental esthetics is a wide field of study which includes a multi-disciplinary knowledge and an approach with a wide outlook, as beauty or ideal esthetics proves to be such a perspective art. Cavity preparation has been well documented, and considerable evidence suggests the most appropriate designs. Shape, contour, and dimensions are all rigorously detailed, but the final morphology and functional requirements of the restoration is not as well described.
Standards as to what is acceptable also are not well documented, at least for direct restorations.
A few examples of carving can be found in the literature, but they are generally limited to small restorations and do not provide an overall guide that may be satisfactory for all types of restorations. Carving that is taught in the Dental Anatomy course is highly theoretical without keeping the principles of clinical carving in mind [5]. For posterior restorations, small incremental techniques have been recommended so that the after effect of shrinkage stress can be reduced.

DISCUSSION
Dental esthetics is of utmost importance when it comes to the completeness of any restorative procedure. The dental component has been proven to be the most recognizable and a major determinant of beauty from times immemorial. The lower third of the face is responsible for maximum depiction of a person's expression and the lips being a hypermobile muscle attracts immediate attention to the persons smile design. It is hence needless to thus mention the key role of a dentist in restoring the natural esthetics of a patient's dental component keeping in mind that natural might not always mean ideal. For this reason, esthetics and smile design is both an art and a science, as it involves the clinician's perception, a keen eye for perfection and at the same time, the patient's intricate requirements to be kept in mind. Today, dental aesthetics and research on Smile Design knows no bounds with advances in every field, including diagnosis, instrumentation, shade selection, material sciences, manipulation techniques and so on.

CONCLUSION
It could be concluded that a thorough understanding of the current information available on esthetic restorations, currently used methods of manipulation of composite material, knowledge on the basis of why precision is a must while sculpting a restoration and also how optical coherence tomography has been inculcated for various applications in dental diagnosis and testing including calculation of voids in resin materials in dentistry was achieved and a limitation, which is micro voids in certain restorative materials, if surpassed, could be an advancement towards the betterment of the artistry which is esthetic dentistry.

LIMITATIONS
Perfectionism in the art of manipulation and sculpting of materials in their plastic/moldable phase requires knowledge of the material aspects as well as the limitations of different materials. One of the major disadvantage of resin based materials, polymerization shrinkage, cannot be eliminated completely although various techniques and protocols have been suggested in the manipulation and restorative procedures for these materials to minimize the shrinkage and associated stresses8. Another limitations of materials in their plastic phase arises when manipulation and carving gives rise to the inclusion of voids or tiny air bubbles within the restorative material mass leading to decreased density of the material. Various studies have tries to overcome this limitation by exploring various other manipulation techniques and restorative materials and have concluded that further research and development is necessary in this field [9]. Prior studies have already identified this limitation and have used advanced methods, to evaluate the void frequency (VF) and void volume (VV) in different flowable composites using swept-source optical coherence tomography (SS-OCT), micro-CT, dyes and by block sectioning [10-14], but have not been able to develop a standardized method to overcome this limitation. Void content in composites is represented as a ratio, also called void ratio, where the volume of voids, solid material, and bulk volume are taken into account.

CONSENT
It is not applicable.

ETHICAL APPROVAL
It is not applicable.