RELIEF

&

POSTERIOR PALATAL SEAL

(POST DAM)

Dr Mostafa Elsayed

Sem1 4.4.2020

Relief

Releif = pressure

Relief Areas

Areas to be relieved:

1-Hard bony areas.

2-Sensitive areas

1-Hard bony areas

Relieved In The Maxilla

• The median palatine

raphe

• Torus Palatinus if

present.

• Thin bony edges.

Relieved In The Mandible

• Thin, wiry, knife-edged ridges.

• Sharp thin bony edges.

• Torus mandibularis

• prominent genial tubercle

Thin bony edges

Areas to be relieved sharp mylohyoid ridge

Superficial mental foramen

sharp mylohyoid ridge

Torus mandibularis

Torus palatines

Thin wiry ridge Torus Mandibulars

Relieved In The Mandible

prominent genial tubercle

.

II. Sensitive Areas: This type of relief is performed for patient comfort

Relieved In The Maxilla

• Incisive papilla in the anterior part of the hard palate.

• Prominent tuberosities.

• Prominent rugae.

Relieved In The Mandible

• Mental foramen area

• Thin mucosa directly covers sharp mylohyoid ridge.

• Thin wiry ridges, which are most common in, lower ridges.

Thin mucosa directly

covers sharp mylohyoid ridge Prominent Rugae

Prominent tuberosities or bony

Relief

Direct

Automatic

Scrape the final impression

Build on the master cast

Methods of Relief

can be performed by either two ways:

• Automatic Relief:

This type of relief can be obtained by the use of a viscous impression material in a closely fitted special tray.

Methods of Relief

• Direct Relief:

• This type of relief can be obtained either by:

A-Scraping the final impression according to the required depth and width of the relief.

B-build up on the cast.

Automatic Relief:

This type of relief can be obtained by the use of a viscous impression material in a closely

fitted special tray.

Direct Relief

• This type of relief can be obtained either by:

A-Scraping the final impression according to the required depth and width of the relief.

B-Relief may be build on the cast .

B-Relief may be done on the cast

• The outline of the relief is determined by the extent of the hard or sensitive areas.

Direct Relief

Depth of relief: • The depth of relief depends mostly upon

resistance or yield of the area to be relieved as compared with that of the surrounding areas.

Shape of relief area differs from case to other

Functions of Relief:

A-Relief areas improve stability of dentures.

B-Compensate for tissue displacement over the ridges during settling of dentures and some ridge resorption.

C-Compensate for some technical discrepancies.

D- Relief of sensitive areas gives comfort to the patient.

POSTERIOR PALATAL SEAL

(POST DAM)

Posterior Palatal Seal Area

The soft tissue area at or beyond the junction of the hard and soft palates on which pressure within the physiologic limits can be applied by RDP (Removable dental prosthesis) to aid in retention of the denture.

• Area of resilient soft tissue between hard & soft plate on which pressure within physiologic limits of tissue can be applied by the posterior border of the denture to aid in denture retention.

Posterior Palatal Seal (Postpalatal seal):

• The seal at the posterior border of a maxillary removable dental prosthesis.

post dam

Anatomic and Physiologic Considerations

• The posterior palatal termination of complete denture should extend from one hamular notch to the other, following the contour of the hard palate over the vibrating line.

Anatomy and physiologic consideration to determine the posterior palatal seal

Vibrating Zone

Post Palatal Seal Area

posterior palatal seal

Three classes

According to the curvature of the soft palate, the palate is

classified into three classes

• Class I: The soft palate has a gentle curvature and this allows a broad palatal seal area.

• Class II: The soft palate has a medium degree of curvature and this allows a medium width posterior palatal seal.

• Class III: The soft palate shows abrupt curvature and this allows a narrow posterior palatal seal.

Width of posterior palatal seal (post dam area)

Depth of post dam area

Depends on the degree of compressibility of soft tissue in this area.

Functions of posterior palatal seal

• Retention of maxillary denture.

• Eliminate the gagging reflex.

• Prevent food accumulation under the denture.

• Compensate for polymerization shrinkage.

Methods to create

1-Scraping method 2-Functional post-

damming

1-Scraping method

• a) Arbitrary method:

• The posterior portion of the denture is determined in the mouth, and its location is transferred onto the cast.

Arbitrary method

Scraping method for post dam

b) Scraping of the master cast

Scraping of the master cast is finished

2-Functional post-damming

This method is based on displacement of posterior palatal seal by impression material at the time of impression making.

Functional method

Any Question