EMERGING TRENDS IN ESTHETICS IN PROSTHODONTICS.

There has been an increasing concern in esthetics and appearance amongst the patients.Hence,the fabrication of a life like prosthesis has become the need of the hour when expected.Demands of the patients regarding their looks and esthetics and the ease and the convenience of the clinician is accomplished with the application of digital dentistry as such. enhanced by characterization of the denture base.A questionnaire survey was carried out in 2016 on denture esthetics and denture base characterization.The results shows that participants gave an importance to denture esthetics and denture gum appearance.Females below 75yrs demanded for characterization in denture base inorder to have natural appearance(4)

Esthetics is a major concern in todaysworld.People are spending millions inorder to have celebrity looks and shapes.There is an increase rate in patients demands for esthetics.In dentistry smile designing is an emerging trend that will satisfypatients needs for a pleasant smile.Inorder to have an attractive smile,both facial and dental assessments should be carried out.The fundamental criteria for fulfilling esthetics are facial,dentogingival and dental esthetics.In recent years several software program for digital smile design has been introduced which will improve diagnosis,communication and enhance the treatment predictability . Facial analysis is performed using reference lines which include both vertical and horizontal reference lines.Horizontal lines are interpupillary and intercommissural lines while vertical reference lines include facial midline,dental midline and mandibular midline.They are crossed against each other to assess symmetry. Dentogingival analysis include parameters of gingival health and morphology such as interdental papillae,gingivalcontour,gingivalzenith,buccalcorridor,blacktriangle.Dental analysis include tooth size,shape and colour of restored tooth.Many theories regarding esthetics which include golden proportion,width to length ratio,pounds theory,law of harmony,dentogenic theory and latest is visagism(1)

Discussion:-
Advances in ceramic and veneering materials help the dentist to restore function and aesthetics using conservative and minimally invasive technique.Advantages of porcelain veneers are they are extremely natural looking.The porcelain veneer and tooth enamel are white and translucent so they reflect in similar manner.Their smooth glazed surface are stain resistant and durable (2).
Emergence of characterization in the field of prosthodontics lead to a new path of visual treat.Characterization of denture base means it mimic the natural colour,shadingand surface texture of natural oral tissues.Pattanaik et al reported the use of auto polymerised pour type denture base resin and acrylic stain for denture base characterization (3).Denture Base characterization is defined in the glossary of prosthodontics terms by the Academy of Prosthodontics as modification of the form and colour of the denture base and teeth to produce a more life likeappearance.Enhancement of white estheticfators(artificial teeth)modification of shape and size of artificial teeth can be carried out based on patients age,sex and personality and pink esthetic factors(denture base) can be ISSN: 2320-5407 Int. J. Adv. Res. 6(10), 983-986 984 enhanced by characterization of the denture base.A questionnaire survey was carried out in 2016 on denture esthetics and denture base characterization.The results shows that participants gave an importance to denture esthetics and denture gum appearance.Females below 75yrs demanded for characterization in denture base inorder to have natural appearance (4) Technique available for interim fabrication by clinician is indirect method,direct method.Indirect interim restoration can be made by additive or subtractive methods.Additivemethods include layering of different hues,opacities and modification of self cure acrylicresin.Subtractive methods such as indirect sandwich technique in which the dentin shaded self cure is cut back from full contour.It is then characterized internally and veneered with more translucent enamel layer.Direct approach include using of either overimpression templates from diagnostic models and wax ups (5) Though various treatment modalities have beenintroduced,implant has become the choice of treatment among patients.But the unfavourable conditions of the alveolar ridge due to atrophy reduce the vertical and horizontal bone volume.The overall gingival contour around the teeth is important for predicting a successful esthetic outcome after replacement of teeth in implant therapy.Advances of CADCAM along with highly efficient artistic skills enable to create life like ceramic tooth replacements.Currently used materials for replacement of artificial ginigva are different forms of ceramic,acrylic and composites.Pink ceramic restorations repairs maxillofacial defects and compensate for inadequate maxilla and mandibular relationships.Itreduces the need for technique-sensitive surgical procedures thus decreasing cost and time. Despite developments in pink ceramics, there are obviously significant limitations in the colour matching, characterization of pink porcelain,diificulty in handling materials (6).
Advances of electronic technology has provided solutions for shade selection and colour matching in dentistry.Various 2equipments used for colour matching are 1. Colorimeters 2. Spectrophotometers 3. Digital camera as filter colorimeter 4. Spectrophotometers and spectroradiometers Advantage of digital shade analysis is that 1. It eliminates the subjectivity of colour analysis and provide correct information for the laboratory fabrication 2. Can be repeatedly verified 3. No influence of external environment 4. Less chair side time 5. The reading can be translated to the materials that can produce exact characteristics(7) 6. Eye fatigue is also reduced Visagism is designing smile based on persons attitude and behaviour which will make it more life-like.Personality can be determined through various methods but most popular method is self-reporting questionnaire asking the participants to mark the statements that describe their behaviour.this forms the basis of novel concept called visagism .the concept of visagism is derived from French name "visage"meaning face. According to Hippocrates,an individuals personality is formed by 4 temperament:choleric,sanguine,melancholic and phlegmatic.

Melancholic/sensitive:
This personality is characterised by kindness.They have oval face with rounded features.Thecentral incisors are oval in shape and the long axis of maxillary anterior teeth is distally inclined.An inverted incisal plane is formed by the connection lines of embrasures descending from medial line.

Phlegmatic/peaceful:
These individuals are kind,cautiousand diplomatic.they have round or square face.Thecentral incisors are small and square shaped and the long axis of maxillary anterior teeth is perpendicular to the horizontal plane.Connection lines of the embrasures are straight.
According to a study byAnuradhasharma,a photographic study was planned to find 1. Correlation between tooth form and temperament. 2. Position of long axis of maxillary anterior teeth to horizontal plane in each temperament 3. Connection lines of the embrasures The results shows that there is definite correlation found between temperament and different parameters of smile.Visagism is a novel concept that applies principles of visual art to the composition of customized smile.Using this method we can design a smile which will correlate with patients physical appearance and attitude. This table shows the total scored by different DSD programs after analysing the facial,dentogingival and dental features.here the maximum is scored by photoshop CS6 and keynote which can be used for orthodontic and surgical reconstruction .Disadvantage is that training skills are required to use these software for smile design.ADSD is the only dentist specific program that include a comprehensive facial analysis to complement dentoginigival and dental analysis.Cerec SW 4.2 could construct a 3D digital model of the patients face to have control over digitally designed restoration.Concept of visagism is used in VisagiSMile (1) With the advance of 3 dimensional intraoral scanner,it helps to produce a design that closely represent definitve smile for patient evaluation and trial restoration.They also helps to make digital impression of the prepared tooth,to process the restoration in computer aided design and computer aided manufacturing and allow complete digital workflow.
Martins et al in 2017 described a case report describing disharmony of anterior teeth.Smile design was developed using software(3 shape dental system).Final design was concluded using vertical and horizontal lines according to symmetry and proportion.The final design was printed to make trial restoration.Teeth were minimally prepared for