1. TRAYS

2. Definitions
Tray
Device Used To Carry The Impression Material To The Mouth, Confine The Material In Apposition To The Surfaces To Be Recorded And Control The Impression Material While It Sets .

3. Impression
Is A Negative Replica Or Imprint Of The Teeth And Adjacent Tissues For Use In Dentistry
Impression Material Is A Substance Used For Making A Negative replica For The Required Tissues

4. Is A Positive Replica (Imprint) Of A Part
Cast (Model)
Is A Positive Replica (Imprint) Of A Part
Or Parts Of The Oral Cavity

5. Types Of Impression Trays
Stock Trays (Various Size & Made By Manufactures)
Custom (Individual Or Special) Trays Made For One Patient And Discarded Later

6. Requirements Of An Ideal Impression Tray
Rigid
Retain Shape
Easily To Be Trimmed And Modified
Smooth Edges
Control Material During Seating, Set &Removal

7. Classification Of Dental STOCK Trays
Metal trays are made of
Aluminum or stainless steel
Non metallic trays are made of
*Plastic (disposable)
**Plastic can be sterilized (xantalgin trays)

8. According to the nature of impression materials
*Plain tray
*Perforated tray
*Rim lock tray
*Water cooled tray

9. Water Cooled Tray

10. # PARTS OF STOCK TRAY
BODY & HANDLE
# Differences between trays for complete denture and those for RPDs

11. TRAY MODIFICATIONS
*Adding
**Bending
***Cutting (aluminum tray)

13. Preliminary (Primary) impression
Is an impression made for the purpose of diagnosis and construction of custom tray
Preliminary (Primary or diagnostic) cast
Positive replica of the upper or lower jaw tissues that is made in an impression and over which custom trays may be made

14. Preliminary Impression Materials
*Alginate (irreversible hydrocolloid) and may be used for
Primary impression for complete denture
Some cases of RPD
Some cases of FPD
Alginate impression should be poured immediately
(WHY) ??????????
** Modeling compound

19. Preliminary (Diagnostic) Cast
*A Positive Reproduction Of The Upper Or Lower Jaw Tissues That Is Made In An Impression And Over Which Impression Trays May Be Made
** Requirements and uses of diagnostic cast

20. Uses OF Diagnostic cast
1- Detection of ridge relationship and inter ridge distance
2-To evaluate the size and contour of the arch
3- To detect areas need to be relieved
4- To construct a custom tray

21. Custom)special &individual) Impression Trays And Construction Of Master Cast
Is an individual tray made over the diagnostic cast and it is used in making a final impression.
Materials for constructing a custom tray
- Autopolymerizing acrylic resin (self- curing)
- Heat cured acrylic resin
- Vacuum adapted resin
- Shellac base plate
- VLC
- Hydro plastic materials

22. Autopolymerizing Acrylic Resin
Easy To be used and require no special Equipment
Technique of construction ;
1) Finger dough adapted technique
2) Sprinkle on method

25. (Dimensionally unstable)
Shellac Baseplate
*Easily manipulate and quickly adapted
**Tend to warp, distort easily, brittle, lack rigidity.
(Dimensionally unstable)

27. VLC (visible light activated resin)
*Urethane dimethylacrylate
**Initiator
***Curing unit has light from quartz halogen lamp
VCL has no monomer, well adapted,,,
excess can be stored to be used later.

28. V.L.C

29. Materials Used For Final Impression
For example:-
Zinc-euginol Impression Paste ( Close Fitting Custom Tray,,, No Spacer
Elastomeric Impression Materials

30. Border Molding
Green Stick Compound Is Traced Along The Sections Of The Tray,,, Patient moves lips Checks And Tongue To Record The Proper Denture Extensions.

32. Pouring & Trimming And Indexing Of Master Cast
Boxing
Is building up vertical walls around the impression usually in wax, to produce the desired size, form of the base of the cast and to preserve the width, height and landmarks of the impression

33. Pour Master Casts b

34. Advantage of boxing 1) Preservation of the border of the impression
2) Controlling the thickness of the base
3) Conservation of time and materials
4) The produced cast free from air bubbles
Methods;
1)Plaster And Pumice ) Putty Methods.
- Indices Permit Removal Of The Casts And Accurate Replacement In The Articulator.

35. Am I natural or artificial molar?????

36. RECORD BLOCKS
Record blocks are fabricated to register the relationships of the mandible to the maxilla at which the denture is made.
Record block consists of
Record base (temporary or permanent)
Record rim (occlusal rim)

37. base
Occlusal rim

38. #Record base
*Temporary (same materials and techniques used for special tray fabrication
**Permanent may be made of heart cured acrylic resin or metal
#Occlusal rim
*Base plate wax
**Modeling compound
***Plaster & pumice

39. Requirements For Baseplate
Well Adapted To The Basal Seat Area AS The Finished Denture.
Have The Same Borders As The Finished Denture.
Rigid & Dimensionally Stable
Easily Manipulated
Smooth & Rounded Edges
Does Not Damage The Cast During Removal or replacement

40. Uses of occlusion rim
1) To establish accurate maxillo-mandibular relation record
2) To determining the length and width of the artificial teeth
3) In arranging the artificial teeth to form the trail denture.

41. Maxillary guide lines

42. Mandibular guide lines

43. MAXILLARY OCCLUSAL RIM
18mm
22MM
4MM
6MM
10MM

44. 5MM
8-10MM
18MM

46. Any Question????????