Introduction: One of the greatest assets a person can have is a smile that shows beautiful, natural teeth. Missing or unesthetic teeth, often lead to a conscious effort to avoid smiling, and other defence mechanisms are used to "cover up" the teeth. The positive psychological effects of improving a patient’s smile often contribute to an improved self- image and enhanced self- esteem. Dentistry has always enjoyed the distinction of being a blend of art and science, and aesthetic dentistry is the art in its purest form. The restoration of a smile is one of the most appreciated and gratifying services a dentist can render, and the branch of dentistry that deals with this is called AESTHETIC DENTISTRY.

Peg shaped lateral incisor(Upper right)

All individuals should maintain a healthy mouth, by following a daily home- care routine, a balanced diet, and regular recall 6 monthly visits to the dentist. Carious teeth, periodontally involved teeth, food habits etc can lead to aesthetically unacceptable teeth and smile.

The following article shall discuss each of the unesthetic situation their cause, their possible prevention and their treatment under each heading.

Stains: Can be either extrinsic of intrinsic. Extrinsic stains are due to intake of foodstuff, such as excess intake of tea or coffee, life style habits e.g. smoking, tobacco or pan chewing. Intrinsic stains are due to physical environment such excess fluoride in water, medicaments for example tetracycline, trauma or general systemic conditions such as congenital porphyria, erthroblastosis fetalis etc.

Trauma: can result in conditions from pulp hyperemia to severe fracture involving the entire tooth. Fractures of the tooth could be small chipping of the incisal edge to severe fractures involving the pulp in varying degrees with or without involving the root.

Aesthetic dentistry offers various treatment modalities, from simple procedures such as conservative alterations of tooth contours and contacts, (cosmetic re- contouring) with the use of composite materials to bleaching(whitening) and invasive procedures such as laminates/veneers, crowns and bridges.

After recountering with composite resins.

Bleaching (tooth whitening): Involves the application of a chemical (oxidizing) solution to the teeth. Bleach solution permeates into enamel or dentin and oxidises the molecules of staining. Applying heat or a combination of heat and light further enhances the reaction. Generally, three or more sittings are required to attain the desired effect. The main objective of bleaching is to restore the normal color of the tooth by decolorizing the stain with a powerful oxidizing or reducing agent. The main bleaching agents used are 30% solution of hydrogen peroxide (superoxol), sodium perborate 10% and carbamine peroxide 10-15%. The number of applications, duration differ as per the needs of the individual patients. ,10 or15% carbamine peroxide is now used by patients at home in a custom made tray under supervision of Dental surgeon . An impression of patients teeth is all that is required for the trays and the gel is dispensed to the patient with trays. Whitening has become easier and more popular as the patients does not need to visit the clinic time and again. People use teeth whiteners even before going for a party now!!

The main advantages of bleaching is no loss of tooth structure and usually low cost as compared to other procedures. The disadvantage is that it is more time- consuming as compared to bonding or veneering. Also occasional touch - ups may be necessary to keep the teeth white.

Composites: These tooth-colored material in lay language can be described as durable plastic compound (resins) that look like ceramic. It is due to their superior physical properties, particularly strength and reduced solubility that has made composites popular. A process called ‘bonding’ is used which involves etching the tooth surface using a mild acid solution, which allows composite resins to adhere mechanically.

To get the desired color various standard shades of the resins are carefully blended so the bonded tooth will look completely natural and as close as possible to the natural teeth.

After application, the resin is contoured into the proper shape and hardens. If the resin is self- cured then it hardens by chemical reaction and if it is light- cured then it is hardens on activation by ultra violet light as the manufacturer specifies, a specific range of visible light. It is then smoothened and polished to achieve the desired form.

The main advantage is that it is a virtually painless, can be usually completed in one or two visits, little or no tooth reduction, less expensive than crowning and avoids potential pulp or gingival irritation. The following procedures are usually carried out with composite resins.

Broken incisor

After repair with resin

1. Composite Recontouring: Frequently, minor modification of existing tooth contours can effect a significant change, this is known as cosmetic recontouring. For example reshaping enamel by rounding incisal angles, opening incisal embrasures, and reducing prominent facial line angles can produce a more femine, youthful appearance in a female patient. One of the photographs here shows cosmetic recontouring of a peg shaped tooth which was recontoured to look like a beautiful incisor. This is done with composite resins.(photographs 1 & 2)

2. Broken Teeth Repairs: Your patient has had an accident and has chipped his teeth. No problem- with resins the patient can look normal within an hour. One of the photoghaphs here shows how good a repair can look.(photographs 3 & 4)

3. Gap Closures: Many patients have ugly looking gaps in teeth. These could again be closed by bonding resins to the sides of the teeth.(see photograph 5 & 6)

Midline gap between teeth

Gap closed with composite resins.

4. Complete Smile Change: Many patients have irregular ugly looking teeth but do not wish to under take extensive procedures. Composites come in handy here. In one or two sittings they can get a more youthful smile with some recontourings, gap closure etc.

Laminates/Veneers: A veneer is a layer of tooth colored material that is applied to a tooth for aesthetically restoring localised or generalised defects or intrinsic discoloration’s.

Laminating is an extension of the bonding technique. It consists of applying veneers, these are thin pre- fabricated shells made of tooth- coloured materials typically made of chair side composite, processed composite, porcelain, or cast ceramic materials, that are bonded to the surface of a tooth to mask malformation, discoloration, abrasion, erosion and faulty restorations.

The best results in terms of resistance to wear, aesthetics and cleansability are obtained from ceramic or porcelain veneers, with less chipping, less staining than bonded restorations. It is a more conservative approach and less expensive as compared to crowning, Though once veneered, they must either be periodically re- veneered or crowned if failure occurs or if decay develops adjacent to the veneers.

A crown is fixed prosthodontic restoration that covers or ‘caps’ a tooth completely, and is the most extensive form of treatment, as the entire tooth surface has to be ‘reduced’ and prepared to fit the crown.

They are used both cosmetically and therapeutically - to improve the appearance (a) of hypoplastic teeth, (b) of permanently stained teeth, © of teeth with excessive tooth loss due to attrition, abrasion and erosion, (d) to protect root canal treated tooth from fracture. These help in restoring the tooth to its functional form. Bridges are used to replace missing teeth. Here the adjacent teeth are crowned and those crowns support the replaced teeth in between.

The most popular choice of crown and bridge modality is metal - fused to ceramic (MFC) which can resolve most of these cases because of its superior aesthetic and high strength. Certain anterior situations not demanding greater strength can tackled using all ceramic crown restorations. Here shade matching is most critical, as the shade of the tooth stalk/stump has to be camouflaged to create superior aesthetics. Lately ceromers based system are becoming popular as aesthetic restoration because of minimal in - office time and lesser laboratory involvement.

Conclusion: Aesthetic dentistry is the most challenging and demanding of treatment modalities, however, the most rewarding too. A choice between the most radical, and the most conservative has to be wisely made, taking into consideration the type, amount and the surface(s) involved, the economic factor and the skills of the dentist to achieve a pleasing result.