In several contemporary dental procedures, patients who need comprehensive removal of teeth with external prostheses are in fact esthetic orphans. Although the introduction of effective osseointegration has significantly diminished the need for reversible prostheses, there are still many patients who are not eligible for implants for clinical, physiological, psychiatric or financial purposes. Such patients deserve the same degree of esthetic restorative dentistry as those of set prostheses repaired. The restorative dentist clearly has the greatest flexibility with complete dentures from an esthetic standpoint. Soft and hard tissues can be supplemented with contemporary defined denture-base materials, and the most stringent patient's demands can be fulfilled with a completely infinite variety of tooth shapes, colors, and arrangements. The biggest problem for partially edentulous patients is the design of a removable partial denture which avoids the unsightly display associated with conventional clasp assemblies. Strategies are available to effectively accomplish this while establishing an environment for optimal periodontal health, and minimizing destructive stresses on the abutment teeth. Esthetic replacement and physiological arrangement of the tooth have made the whole denture biologically compatible and desirable. To improve the patient's psychology, proper dent positioning should be practical and esthetically pleasing. This article reviews the evolution of teeth selection concepts, as well as recent techniques used to select anterior teeth for complete dentures.
Introduction:
It may be due to periodontal disorder, abscess
development, infection, and vertical tooth fracturing that causes edentulism or
total tooth loss. Common consequences of tooth loss include progressive
resorption of the alveolar bone and reduced performance in chewing. Edentulism
has two main limitations as it affects the capacity of a individual to perform
two important activities in life: speech and feeding, and impairment, because
drastic improvements are made to account for the deficiencies[1]. Both
disability and disability have had a negative impact on psychosocial
well-being, particularly with regard to the elderly. Additional to quality of
life, edentulism affects oral and general health[2]. The edentulism treatment
includes conventional complete dentures (CCDs), implant-retained overdentures
(IODs) and, in some cases , full-arch fixed complete denture prostheses
supported by implants. In the past, restore function with completely removed
dentures has been the most successful procedure for edentulism. Since
edentulism triggers progressive boneloss, CCD treatment is minimal and negative
changes occur overnight. Common problems, particularly with mandibular CCDs,
include lack of stability and retention, discomfort and pain and additional
loss of function[3].
Aesthetics is the primary consideration for
patients seeking treatment with prothetics. The size and shape of the anterior
maxillary teeth are not only important for dental esthetics but also for facial
aesthetics. The goal is to restore the anterior maxillary teeth in accordance
with the appearance of the faces. However, the dental literature provides no
scientific evidence to be used as a reference for identifying the correct size
and form of anterior teeth or for determining natural relationships. According
to Young, "beauty, harmony, naturalness and individuality are essential
qualities" of esthetics[4].
The schematic division of face shape and head,
which Madame Schimmelpeinik proposed for use by artists in 1815, was considered
for the application of esthetic teeth in the dentistry. The concept of
"correspondence and harmony" was projected by J.W. Blanc in 1872. The
basis of this concept was that the temperaments demanded a characteristic
association of the shape and color of the tooth, and that harmony required a
corresponding proportion and size of the tooth to that of the face, and a color
of the tooth in harmony with the complexion of the face; that the shape and
color were modified to be in harmony with sex and age. The dentist challenge
was to combine and complement these different field values into a dental
condition description which was helpful for determining the shape of the tooth.
From the point of view of power and general
acceptance[5], the "Temperamental technique" of choosing the tooth
type should be considered chronologically the fourth technique and the first
technique.
Projected in 1906, "Berry's biometric
ratio system" He found out the proportions of the upper central incisor
tooth had a definite proportional ratio to the proportions of the face. The
tooth was one sixteenth the width of the nose, and one twentieth the length of
the neck.
Discussion:
There are a host of patients whose financial,
anatomical, psychological, or medical limitations eliminate them as candidates
for fixed implant or prosthodontic therapy. These patients can often be treated
with removable prosthodontic therapy with satisfactory results. Such patients
do have the same esthetic expectations and preferences as patients diagnosed
with restaurations assisted by set prosthodontics and implants, and they
receive the same quality of treatment. Once again, the writers are of the view that
these patients are frequently regarded as second-class people and are given
what can better be characterized as a medium level of restorative treatment.
The article explores the wide area of reversible prosthodontics when it
pertains to esthetics and analyzes the obstacles to presenting these patients
with an outstanding degree of restorative therapy. Suggestions are provided to
help the doctor have both full dentures and temporary partial dentures with a
high degree of esthetic treatment.
Complete dentures
Complete dentures offer the clinician the
ultimate freedom in providing esthetics which are accepted by the patient.
Given today's near-infinite variety of tooth molds, shapes, colors, and
designs, the clinician is constrained only by his ingenuity and artistic
talent. The teeth can be placed in nearly any position needed to provide
optimum support for the lip and a pleasing smile. The denture-base material can
make up for loss of hard and soft tissue. Both the teeth themselves and the
denture-base materials can be modified and characterized to tailor each
prosthesis to the needs and wishes of the patient (Figure 1). Clinicians have
developed many contemporary principles of esthetics which provide complete
denture prostheses. The dentogenic concepts described by Frush and Fisher use
the patient's gender, personality and age in the selection and arrangement of
anterior teeth, and have been used extensively by clinicians for many years.[1]
The concepts of the divine or golden proportion have also been described and
provide useful guidelines for the selection and positioning of anterior teeth.
Clearly, a highly esthetic, personalized, complete denture service can be
offered to patients. Providing such a facility is both gratifying and
satisfying, which helps the clinician to study much of the concepts of
esthetics experientially, and can then be extended further on to fixed
prosthodontics and implants. Few data on the quality of care rendered with
complete dentures are available; however, the authors are of the opinion that
the majority of complete dentures provided are not close to
achieving the esthetic potential currently possible. Thus, many practitioners
lack a tremendous opportunity to provide an upscale service while learning and
applying many important principles that are critical to the field of esthetics.
Infrabulge Clasp Assemblies
This first choice is the simplest and easy to
use, and should often be weighed before solutions become more complicated. As
is the case with suprabulge clasps, infrabulge clasps approach the retentive
undercuts from the gingival rather than the occlusal direction. [1] This design
feature alone can eliminate many patients' display of the clasp assembly,
depending on their individual smile. The use of infrabulge clasps with the
rest, proximal plate, I bar (RPI) concept and its modifications has been well
documented.[6]
Based on these concepts, infrabulge clasp
assemblies have the advantage of presenting relatively clean lines, with
minimal interference with the natural contours of the abutment teeth, and are
stress-releasing. They can thus be used in cases of Kennedy Class I and II, as
well as in circumstances of tooth born. Additionally, infrabulge clasps have
inherent tripping action which makes them more retentive than suprabulge clasps
with the same undercut depth[7].
Figure 2 shows
the successful use of infrabulge clasps on a partial denture removed from the
mandibular Kennedy Class I to provide optimal function and esthetics. While
this choice would not meet every patient's esthetic demands, it is a simple and
effective idea that effectively fulfills certain demands in many whose smiles
require it. Remember that a changed cast impression was used with this
individual to better connect the base of the denture to the residual ridge soft
tissues. It has been well established that the most critical factor in
mitigating stress on abutment teeth with removable partial dentures is the
optimum fit of the base to the residual edge, and this is best accomplished
with the altered-cast impression technique Less than 2 per cent of North
American dentists use the altered cast which gives credence to the authors'
assertion that removable prosthodontics
Precision Attachments and
Serniprecision
A second approach to replacing the clasp
assembly show of adjustable partial dentures is to start using precision or
semi-precision attachments. According to the authors, the attachments to
precision are generally misunderstood and overused in the profession.
Attachments were classified as intracoronal or extracoronal and resilient or
non-resilient and each type of attachment has significant inherent deficiencies
associated with them. Place for the attachment inside the crown must be
provided for intracoronal attachments. This must be recognized at the time of
the preparation of the tooth and often leads to the removal of a considerable
amount of sound tooth structure to fit the attachment. This loss of sound tooth
structure represents a significant intervention in the abutment tooth's structural
integrity, and requires a biological price that is often paid at a later date
(Figure 3). By definition, extracoronal attachments alter the physiological
crown contour of the abutment tooth and often establish a clinical situation in
which it is extremely difficult if not impossible for patients to maintain
adequate oral hygiene under the attachment. Again, this usually requires a
biological price, in the form of parodontal disease or recurrent caries or
both. A great variety
of extracoronal attachments are available, and their style and size differ
considerably. In general, the authors are of the opinion that extracoronal
attachments with natural abutment teeth should be avoided. When selecting an
extracoronal attachment for use, it is recommended that one of minimal size be
chosen to mitigate the impact on the anatomical contour of the crown, and that
the patient be trained and advised to exercise careful oral hygiene to avoid
the production of pathology.
The second approach with attachments which is
potentially useful is to use plunger attachments. This approach is relatively
straightforward in concept and has been proven practical in many clinical
situations. Such devices are essentially spring-loaded plungers that work in
the partial denture casting in a cradle and maintain a dimple in the proximal
surface of the abutment tooth or crown. These attachments can be used in both
tooth-borne situations and carefully in cases of Kennedy Class I1.[8] In these
latter situations, it is critical to obtain maximum stability of the base of
the denture by using a technique of correct impression. Such attachments may be
categorized as durable as they enable vertical and horizontal mobility and can
be adapted to the relative amount of retention offered simply by changing the
amount of pressure exerted by the plunger. A critical principle with which to
achieve this. A and B, Plunger attachments are placed in a cradle of the
partial denture framework and can be adjusted to give varying amounts of force.
C, It is important to preserve the location of the abutment teeth by using
plunger attachments and this is achieved optimally with milled lingual bracing
arms and supportive proximal rests. The attachments gain stability in the
abutment tooth position by constructing a partial denture frame. This can be
done by using a milled lingual brace arm with a positive proximal rest,
splinting the abutment teeth or a positive cingulum rest. If that is not done,
it can be orthodontically pushed out of place by constant pressure of the
plunger attachment against the abutment tooth.
Concepts of Teeth Selection
White’s Concept
This method was based on a concept ascribed to
Hippocrates in the 5th century BC. Temperamental types were sanguine, anxious,
cheap and lymphatic named for the individual's bodily functions of blood,
muscles, bile, and lymph. The fake teeth were randomly chosen to match the
personality of the recipient. It would be expected that a "balanced"
individual would have short, broad, tapering incisor teeth, while a
"bloody" individual would have long, thin, and narrow teeth[9].
H.Pound’s
Concept [10]
Evaluates tooth width by "measuring the
gap between zygoma and zygoma, one and a half inches back of the lateral eye
corner"
Duration is a calculation of the distance from
the chin's hairline to the lower edge of the chin 's surface, with the sleeping
ear.
Dentogenic
Concept
[11]
The collection of tooths using dentogenics
principles is based on the patient's age , sex and temperament putforth by
Frush and Fisher 1955. This definition was clarified as the prosthodontic
understanding of the presence of three essential factors each patient
possesses. The factors for this are the patient's sex, personality and age.
Winkler’s
Concept [12]
This definition has three aspects to emphasise.
The point of view biological-physiological, biomechanical, and psychological.
The biological-physiological point of view stated the importance of facial
musculature harmony and the physiological limit to the arrangement of the
teeth. Biomechanical reveals the mechanical limitations of anterior teeth
placement. The psychological perception is based on facial presentation and
esthetics.
The Concept by
Leon William[13]
William invented a system which is called
harmony law. He assumed that in most cases, there is a connection between the
inverted face shape and the maxillary central incisor shape. Three traditional
types of teeth he described as square, tapering and ovoid.
Anterior Teeth Colour
Bilmeyer and Saltzman defined color as the
result of the physical modification of light by dyes as seen by the human eye
and interpreted by the brain. Light is physical, colorants are biological, the
body is physiological and the brain is neurological of course. Actually the eye
is psychological in nature as a receptor interfaced with the brain as an
interpreter. The color definition is indicative of the variables inherent in
color visualization and control.
When viewing a tooth to determine its color,
two main colors––yellow and grey––are evident. In the gingival third the yellow
is more dominant, and the black is more prominent in the incisal third. Patient
position and light source are very important in color selection [14]. The
patient should be standing upright. The dentist should be in a position to show
the teeth in a direction that is perpendicular to the imaginative dentist plane.
In the electromagnetic spectrum, white light of the wavelength between 380 and
750 nm is considered appropriate. Eyes tire of color perception very quickly,
therefore they should not focus more than a few seconds on a tooth. A gap of
6–8 feet should be set between the teeth and the shade guide.
Color Dimensions
Color control factors can be controlled in
three basic variables: variables of observers, variables of objects and
variables of light source. This is called geometric metamerism, or a play of conditional
light. The middle incisor shade has been picked from an appropriate shade
guide. The dentist should consider the patient's age, the individual complexion
pattern and the patient's desires in choosing this shade. Acceptable teeth
color values are always compromises between those three factors. Hue, Meaning
and Chroma[15] are the three dimensions of light. Hue depicts an object 's
dominant colour. Value describes a colour's lightness and gloom. Chroma
describes the level of saturation of the color in question. Such three
dimensions are usually included in shade tabs to help the clinician and the
laboratory technician select a suitable teeth to complement the patient's
appearance.
Light is the origin of color — the primary in
the triad of source, object, and observer — it is seldom considered by people
who see color as such. Incandescent light, which is commonly used in home and
most operating lamps, emits a lot of energy in the spectrum 's red yellow area
and very little energy in the blue zone. Therefore, if we illuminate red,
yellow and blue samples under the source of incandescent light, we will see
that the red and yellow are very strong and highly saturated. While the blue is
faint and lacks saturation. It is considered a best source of natural daylight.
In history, certain proportions have evolved to
describe the esthetics of faces. Proportion is the study of structural harmony
in space. The esthetic proportions that remain from ancient times are golden
proportions. Now in the recent years recurrent esthetic proportions are argued.
Esthetics may continue to be ignored in favour of the mechanical principles of
function, but not without sacrifice of a pleasing and harmonious expression [16].
Conclusion
It
is obvious that removable prosthodontic procedures are often not provided at
the optimum level, given the current level of knowledge. Clearly, patients
requiring removable prothodontic care have the same esthetic desires as
patients receiving fixed prosthodontic therapy, and they deserve the best
treatment outcome possible. Dentists have maximum flexibility to achieve
patient-accepted esthetics for complete dentures. The infinite variety of tooth
molds, shapes, and colors, along with multiple shades of denture-base resin and
the ability to define tradition, offer the clinician expertise and ingenuity
effective tools to deliver optimum esthetics. The primary esthetic problem with
removable partial dentures is display of the clasp assembly. Often this unesthetic
display can be avoided just by using infrabulge clasps. The attachments to
precision are not well understood and are overused. The use of precise
attachments can provide esthetic results in the short term, but the
manufacturing of such prostheses is both complex and time-consuming, and the
long-term maintenance required is a major problem. Before committing themselves
and their patients to using attachments, clinicians should consider other
options with care. Partial dentures removable by rotational path are also
poorly understood and tend to be underused. However, they can provide an
exquisite, cost-effective means of delivering great esthetics and function.
This approach is highly recommended where indicated. Finally, providing
excellent removable prosthodontic service in other disciplines is no different
than providing excellent service in other. In all stages of care delivery it
simply requires meticulous attention to detail. The essential details are well
known in the literature and have been described in detail. This article
attempted to motivate practitioners to elevate their removable prothodontic
service to the level they deserve for their patients.
Dental
art is not an automatic occurrence. The dentist must incorporate this
intentionally and carefully into the treatment plan. This artistry aims at
softening the marks put on the face by time and encouraging people to face
their life with renewed enthusiasm and trust. Art in conjunction with the
denture development sciences promotes the preservation of physical and
psychological health by the geriatric patient.
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