Revision on Practical Dental Materials RDM211 DENTAL BIOMATERIALS.
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Transcript of Revision on Practical Dental Materials RDM211 DENTAL BIOMATERIALS.
Revision on Practical Dental Materials
RDM211
DENTAL BIOMATERIALS
Mechanical properties
DIAMETRAL TENSILE STRENGTH TEST
THREE POINT BENDING (TRANSVERSE STRENGTH TEST
Testing compressive strength of a material:
• Specimen shape: Cylindrical
• Type of force used: compression
•Tester: Universal Testing Machine
Dumbell shaped specimen
Disc shaped specimen for diametral TS
Diametral compression test of brittle materials:
• Specimen shape: Disk-shaped
• Type of force applied: Compression
• Resultant force: Tension
• Tester: Universal Testing Machine
Stress = 2P Load π D T
Diameter XThickness
Hardness testers
STOCK TRAYS
Acrylic special tray
1-IMPRESSION MATERIALS
Impression compound low fusing sheets and sticks(green)
compound(
• 1) An impression compound disc
• 2) An impression compound impression taken in an upper edentulous stock tray
LOW FUSING COMPOUND (GREEN COMPOUND).
ZINC OXIDE EUGENOLIMPRESSION PASTE
Glass slab and spatula
ZINC OXIDE EUGENOL SECONDRY IMPRESSION
ACRYLIC SPECIAL TRAY WITH BORDER MOULDED (USING LOW FUSING
COMPOUND) READY FOR MAKING ZOE IMPRESSION
PRIMARY COMPOUND IMPRESSION
INPRESSION COMPOUND SHEETS
Agar syringe and tray material
• Syringes:Syringes: low viscosity – high flow. low viscosity – high flow.
• Tubes:Tubes: high viscosity – heavy body: low flow. high viscosity – heavy body: low flow.
AGAR-AGAR CONDITIONER
Three compartments conditioning bath
Water cooling system tray for agar impression
Alginate
Rubber bowl and broad bladed spatula
Alginate impression
polysulphide
•Mixing on paper pad or glass slab with medium blade spatula.
Manipulation
•Kneading
Addition siliconeHow many consistency
Vinyl glovesLatex gloves
Condensation silicone
• Condensation silicon– By-product
– ethyl alcoholInaccuracy (shrinkage)Poured as soon as
possibleNeed very dry field
(hydrophobic) Advantages:
Clean, pleasant odour
Addition silicon:No byproduct
Release H2 gas after settingDelayed pouring
Hydrophobic
Advantages:Good dimensional stability
Tray adhesive
Auto mixing gun and cartridges
Static mixing tips
Rubber base impression
Light body
Heavybody
2 -GYPSUM MATERIALS
STONE CAST
Die
Rubber bowl and spatula
Semi mechanical mixer
Vacum mixing machine