1. RELIEF
Dr Nora sheta

2. Relief
The reduction of undesirable pressure from specific areas under the denture

3. Defintion : Relief area:
“ Area in the fitting surface of the denture that is reduced to eliminate excessive pressure.”

4. 1-Median palatine raphae
2-Torus palatinus {if present}
Torus mandibularis {if present}
1-Incisive papilla
2-Rugae area
3-Flabby ridge
4-Sharp bony spicules
1-Mental foramen in resorbed ridges
2-Flabby ridge
3-Sharp bony spicules

5. Shape of Relief Area
It is never well defined. It merges into the surrounding fitting denture surface.
It depends on the compressibility of the area to be relieved as well
as that of the surrounding areas.

7. Methods of Relief
I- Direct
1-Scrap the final
impression
2-Build tin foil
on the master
cast
II- Automatic

8. I- Direct Relief 1- Scraping the Impression
In plaster of paris impression material

9. I- Direct Relief 2- Build on the cast

10. I- Direct Relief 2- Build on the cast

11. II- Automatic Relief (Selective Pressure Impression Technique)
B- Secondary impression in Zn/O eugenol or plaster.
A- Scraping the compound
selectively.

12. Value of Relief
Relief of sensitive areas increases the comfort of the patient.
Relief of hard areas improves the denture stability, so it
Prolongs the duration of denture service by compensating for denture settling and some ridge resorption .
Compensate for polymerization shrinkage.

13. Posterior palatal seal ”post dam”

14. Definitions
1- Posterior palatal seal : “ A slight elevation at the posterior border of the maxillary denture .”

15. Definitions
2- Post damming : “ Slight compression of the soft tissues along the posterior border of the denture whether upper or lower .”

16. Definitions
3- Posterior palatal seal area “Area of resilient soft tissue at or beyond the junction between hard & soft palate, on which pressure within physiologic limits of tissue can be applied by the posterior border of the denture to aid in denture retention.”

17. Position of the Post dam area
Posterior vibrating
line

20. Functions of posterior palatal seal
Retention of maxillary denture.
Prevents food accumulation under the denture.
Compensates for polymerization shrinkage.
Reduces patient’s discomfort.

21. Requirement of the effective posterior platal seal
Easily displaceable tissue
imovable tissue
Touch the soft palate during rest and function

23. Width of post dam area

24. Depth of Post Dam
Depends on the degree of compressibility of soft tissue in this area and on the extent of functional movement of the soft palate.

28. postdamming
Methods of
1-Scraping method
2-Functional method

29. Methods of post damming
1-Scraping method

34. Methods of post damming
2- Functional method

36. Methods of post damming
2- Functional method

38. Post damming of the lower denture
A lower impression may be post dammed by slightly compressing the soft tissues formming the pear shape retromolar pad

39. Thank you