general dentistry &
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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