2. About the Article...
Australian Dental Journal. August. 1980
; Volume 15, No. 4
Ronald L. Ettinger, & Forrest R.
Scandrett, College of Dentistry. The
University of Iowa. IOWA CITY. U.S.A.
4. Introduction
• Well fitting denture
• Peripheral border should compatible with the
muscles and tissues
• is PPS necessary ???
(A comparison bases having palatal seal of the retention of complete
denture different types of posterior William E. Avant, P J. Prosthet. Dent.
May. 1973)
6. • The soft tissue area limited posteriorly by the
distal demarcation of the movable and non-
movable tissues of the soft palate and anteriorly
by the junction of the hard and soft palates on
which pressure, within physiologic limits, can be
placed; this seal can be applied by a removable
complete denture to aid in its retention ( GPT 9)
7. Functions :
(1) to provide retention
(2) to prevent food from getting under the denture
base
(3) to diminish gagging
(4) to make the sunken distal border less conspicuous
to the tongue
( 5 ) to supply a thick border to counteract denture
warpage due to dimensional changes during the
curing process
(6) Creates partial vacuum when horizontal & tipping force
are applied
21. Different techniques to record the PPS
I ) techniques
of scraping the
cast,
(2) a selective
loading
impression
technique,
( 3 ) a
physiological
impression
technique.
23. •Watt and Mac Gregor believed in
scraping a double bead,
Watt and Mac Gregor ; Designing complte
dentures. Philadelphia, W. B. Suunders
Company. 1976
(pp. x3 R6).
24. • Winland and Young" have described the six most common
posterior palatal seal configurations used in the dental schools
of the United States as :
• I . A bead posterior palatal seal.
• 2. A double bead posterior palatal seal.
• 3. A butterfly posterior palatal seal.
• 4. A butterfly posterior palatal seal with a bead on the posterior
limit.
• 5. A butterfly posterior palatal seal with hamular notch area cut to
half depth of a No: 9 bur
• 6. A posterior palatal seal seal construction in reference to
House’s classification of palatal forms
class 1 : flat: modified butterfly- 3-4mm wide
class 2 : high : modified butterfly 2-3mm wide
class 3 : intermediate - a bead
25. Selective loading technique
• Impression making under constant load and
taking into account the varying tissue
densities
(Graham. C. H. The importance of stress bearing areas in
full denture impression technique. Proc. 11th Aust. Dent.
Cong., Perth. 1948 (pp. 3-15)
26. • Mapping out the relief areas in the initial
impression
• Fitting tray with relief in foil / wax / scraping
the tray
• Undercut areas , incisive papilla, midline
suture, excessive mobile tissue areas
• low fusing compound
• Escape holes
27. Physiological posterior palatal seal
• Mouth temperature
impression wax
• Displace the soft tissues
within physiological limits
29. Conclusion
The most common problem associated with lack of
retention of the maxillary complete denture is a faulty
posterior palatal seal. Many dentures do not cover the
tuberosities. nor do they extend into the pterygomaxillary
notches. while others are extended too far posteriorly
past the vibrating line.
A careful examination of the patient's tissues helps to
delineate the anatomical boundaries of the posterior
palatal seal area so that an adequate seal can be
established.
30. References
• Avant. W. E. ~ A comparison of the retention of complete denture
bases having dill’erent types of posterior palatal seal. J. Prosthet.
Dent.. 29: 5. 484 493 (May) 1973
• Essentials of complete denture prosthodontics Sheldon Winkler
2nd edition
• Hardy, I . R.. and Kapur, K. K. ~ ~ Pohterior bordcr seiil~- i t s
rationale and importance. J. Prosthet. Dent. 8 :3. 386 3x7 (May) 1958.
• Edwards, L. F., and Boucher. C'. 0 Anatomy ofthe mouth in relation
to complete denturcc J.A.D.A.. 2Y: 3, 331 345 (Mar.) 1Y42
31. • Bylicky, tl. S. Vnrinhle approaches in obtaining ii post palatal bcal:
Description of technique. Neh Yurk J. 1)cnt.. 36: 8. 180 2K-7 (Ocl.)
1966.
• Zach, G. A., and Appleby, R. C . - Importance of hamular notch in
denture construction.-Iowa Dent. J.. 52: 4, 26 27 (Oct.) 1966.
A well fitting and retentive complete maxillary denture requires a well fitting tissue surface, a peripheral border compatible with the muscles and tissues which make up the muco-buccal and muco-labial spaces so that a peripheral seal is created by the soft tissues draping over them. and. finally, a posterior palatal seal. Avant[ has shown that ”a posterior palatal seal is necessary for optimum retention of maxillary complete dentures” and that of the designs he tested, none proved to be superior in all of his five test subjects. This paper will review the various techniques used in establishing a posterior palatal seal and discuss the problems associated with each method.
ANTERIOR VL- imaginary line located at the junction of attached tissues overlying the hard palate and the miveable tissues immediatedly adjcent the soft palate