General dentistry &

General Dentistry &Artificial TeethASST PROFESSORDr Mumtaz ul IslamB.Sc. BDS. MHR. M.Phil.

General Dentistry

Impression and Model

Model or Cast

Die

Posterior Bridge

Anterior Bridge

Crown

Dental Implant

Cast Partial Denture

Complete Denture

GV Blacks Classification

Artificial Teeth

Dentistry Common perception False teeth Main component of a denture Acrylic and porcelain

Requirements

Appearance Attachment & compatibility Low density Strength Hard enough for masticatory forces Allow grinding with burs for adjustment

Acryilc Teeth Production

Produced in moulds (metal, reuseable) Dough moulding technique Injection moulding Highly cross linked resin Resistant to crazing Tooth coloured pigments no pink colour

Porcelain TeethManufacturing

According to required shapes and sizes Moulds kept 30% larger than required Disposable moulds Mechanical attachments Metallic pins or holes

Properties

Aesthetic Density 1.2 & 2.4 Coefficient of thermal expansion (acrylic 80 porcelain 7) Modulus of elasticity (GPa) 2.5 & 80 Hardness (VHN) 20 & 500 Occurrence of radioactive compounds (uranium-238)

Properties

Contd.

Wear in acrylic teeth especially in dusty or gritty environment Acceptable appearance Convenient handling Greater toughness compatibility Surface stains incorporation

Disadvantages

Bonding, cracking or crazing of denture base Fracture and chipping of porcelain teeth Difficult to grind for adjustments Porcelain teeth transmits excessive force Contraindicated for resorbed ridges and diminished interocclusal

distance Surface stains are less stable in acrylic teeth