Esthetic enhancements in Complete Dentures

I presented this paper at the National Dental Students Conference in Belgaum, 2009.

This work was published in the Journal Of the Indian Dental Association, JIDA, 2009, 3 ; 241- 243

Esthetics in complete dentures is more spoken of than practiced. Yet it remains a very important patient requirement in many situations and poses a challenge to the clinician.
Esthetics is defined as the skill and technique used to improve the art and symmetry of the teeth and face to enhance the appearance as well as the function of the teeth, oral cavity and face.1
The beauty about Esthetics lies in the fact that it is relative. What may be esthetically pleasing to an observer may not necessarily be the same to another. Inspite of this subjective nature of esthetics a well accepted fact is that an ideal conventional arrangement as is done for most complete denture cases gives dentures a standard/universal look which sometimes can look artificial.2
It is unreal to expect a natural look in elderly patients who wear dentures with nice shiny teeth, arranged in an ideal arch form and alignment, with perfectly sculpted gingival margins. A more realistic appearance for an older individual can be brought about by dentures which exhibit some attrition of teeth, gingival recession, tooth and gingival discolouration.

THE DENTOGENIC CONCEPT

The first attempt to incorporate esthetics as a separate important entity in complete dentures was by Frush and Fischer who introduced the Dentogenic concept. It is the art, practice and technique of creating an illusion of natural teeth in artificial dentures and is based on elementary factors suggested by the sex, personality and age of the patient.3
The 3 main aspects that can be looked at by the clinician to produce esthetically pleasing dentures are 3
1)Selection of the teeth4,5,6
2)Arrangement of teeth2
3)Characterization of denture

• Teeth are selected according to their shape, size, colour and material to match the patients needs and requirements2. Dentogenics stresses that they should be selected keeping in mind the sex, personality and age of the patient .3
• Smaller teeth with rounded line and point angles, rounded incisal edges give the teeth and the arrangement an over all feminine touch.
• Larger teeth with flat edges, sharper line and point angles are more suited to a vigorous and masculine personality. 7
• Chipping of teeth , overlapping of teeth are extremely common in natural dentitions and can be incorporated in the denture arrangements to make them look more natural. Some of the rules laid down in the literature for the above can be summarized as part of the ‘Dynesthetic concept’ of arrangement of teeth given by Frush and Fisher.8

Some of the principles highlighted in this concept can be used as ‘tips’ by the clinician as well as the laboratory technician to enhance the result and are summarized below:

• Maxillary central incisors arranged in labioversion or with labial inclination look more pleasing.
• Visibility of the teeth on speech must be such that the tip of the lateral incisor is just visible on speaking.
• Central incisors must be arranged so that in young females and in young males they are 3mm and 2mm visible respectively below the lip in resting position. In older individuals the incisors are not kept visible at all or just at the level of the upper lip.8
• The central incisors must dominate the anterior composition while the lateral incisors are considered to be the personality tooth. Sex determination comes from either rounding off the incisal edge of the lateral to depict feminity or squaring the edge to depict masculinity.9
•  Diastemas must be judiciously placed so that they don’t serve as food traps and at the same time look esthetic2. All spaces must be V shaped to shed food. A diastema between the central incisors is avoided. Diastemas should be asymmetrically placed on either side of the dental arch.
• The gum line must be placed at varying levels so that it is highest on the canines, followed by the central incisors and is the lowest on the laterals.2,8
• The interdental papilla must be hygienic self cleansing and convex in all directions.

These rules are a guide and not a compulsion to be applied to all cases.
Characterization of dentures is the least explored of all options to add to the esthetic value of dentures2.It involves incorporation of subtle features in the dentures to give them some individuality.

The advantages of denture characterization are
a)It is a simple procedure
b)Does not require complicated/sophisticated/expensive materials or equipment.
c)It is not time consuming
d)It greatly enhances the esthetic outcome of the complete denture.

Characterization can be depicted easily by
a)Incorporation of stains.
b)Depth grinding.
c)Modification of incisal edges
d)Incorporation of restorations.
e)Incorporation of rotations.

Natural teeth and restorations like composites, usually tend to get stained by coffee, turmeric, paan, tobacco, and colouring agents in food. These stains are normally prominent on the proximal margins and cervical areas8.

Depth grinding involves sculpting of teeth to attain a desired morphology to compliment the patient. The mould of the tooth can also be modified to incorporate abrasion, erosion, masculinity or feminity. For example, incisal edges can be flattened to depict attrition or the mesial and distal line angles can be modified to alter the facial contour of the tooth. Chipping of teeth is usually seen in older teeth, especially in the incisors. Such replication of broken down teeth can create a pleasing natural look. 9,10

Restorations such as composites for the anteriors and silver amalgam for the posterior teeth can be judicially incorporated in the dentures. Such restorations serve a dual purpose. Besides adding to the natural look of the dentures, they also serve to distract the onlooker’s mind from the fact that the patient has an artificial dentition.

The authors recommend the following indigenous method for denture characterization along the above mentioned principles.
1. Staining of denture teeth- Inorganic rare earth pigments are used. These are dissolved in monomer and painted on the surface of the tooth as required. A variety of colours may be used. For example, red pigments can be used to depict paan stains, brown pigments subtly placed around the margins of restorations can suitably depict coffee/food stains. The stains are covered by a thin layer of Bonding agent which is light cured.11

2. Depth grinding- This can be incorporated with a universal wheel, cylindrical and tapered fissure diamond burs used with a micromotor hand piece. The labial surface of teeth can thus be sculpted to alter the contour. The incisal edges can be flattened, or they can be chipped away, the proximal contact areas can be broadened to depict age changes. The modified teeth are then polished before arrangement.9,10

3. Restorations- In posterior teeth, cavity cutting is done and amalgam restorations can be incorporated, especially on the occlusal surface of mandibular teeth. Composites restorations with a subtle colour mismatch can be incorporated on the anterior teeth to give them a natural appearance.

4. Denture base characterization – A natural appearance can also be incorporated in the ‘pink’ zone of the denture. Gingival inflammations are commonly depicted by rolled marginal gingivae. Inflammation can be depicted by incorporating a generalized swelling of the attached gingiva with a loss of stippling. This is done at the stage of waxing up of the dentures. The same inorganic pigments described above for staining of teeth can be used for pigmenting denture bases. Red pigments can be painted in a dilute form to depict inflammations while a mix of brown and black can be painted on in patches to simulate the melanin pigmentation of attached gingiva which is a very common Asian trait. These painted areas are sealed in by covering a thin layer of clear self cure acrylic resin which is then polished.


Therefore it may be realized that the esthetic outcome of complete dentures can be very easily enhanced by application of principles of dentogenics and carrying out denture teeth and denture base characterization wherever possible. Taking an extra step to pay due attention to the esthetics of a denture can go a long way towards ensuring success with complete denture treatment.
Characterization also is of great importance when the opposite dentition is a natural one especially that with spacings, stains  and pigmentation.


References

1)Mosbys dental dictionary,Elsevier,2nd edition,pg:229,2008
2)Charles M.Heattwell,Arthur O.Rahn,Heartwell ,4th edition-1984,Akshar Pratiroop Pvt.Ltd,pgs:97-104,309-324,375-389.
3)Frush J,Fisher R:Dentogenics:Its practical application.J.Prosthet Dent 1956,9:914-921,1959
4)Zarb,Bolender,Boucher,Elsevier,12th edition,pg:298-320.
5)Sheldon Winkler,Winkler,2nd edition 2000,A.T.B.S Publishers&Distributors, pg:202-216.
6)Felix.A.French,The selection and arrangement of the anterior teeth in Prosthetic dentures,1951
7)Frush J, Fisher R : How dentogenics interprets the personality factor. J Prosthet Dent 1956, 6: 441-449
8)Frush J, Fisher R : The dynesthetic interpretation of the dentogenic concept. J Prosthet Dent 1958, 8: 558-581
9)Frush J, Fisher R : How dentogenic restorations interpret the sex factor. J Prosthet Dent 1956, 6: 160-172
10)Frush J, Fisher R : The age factor in dentogenics. J Prosthet Dent 1957, 7: 5-13