REMOVABLE PROSTHODONTICS

Factors that influence the form and the size of the supporting bone include the following:

• The severity of the periodontal disease
• Quantity of saliva
• The relative length of time different parts of the jaws have been edentulous
• The compliance of the patient
• Quality of life

Mandibular stress- bearing areas are:

• Firm tuberosities
• Buccal shelves
• Retromolar pads
• Rugae
• Hard palate

*To make an ideal impression, the following concepts should be adhered to:

• The tissue of the mouth must not be healthy
• Proper space for the selected impression material should not be provided within an impression tray
• The impression should extend to include the entire basal seat
• Border modeling procedure is not necessary
• Correct positioning of the impression tray in the mouth doesn’t need a guiding mechanism

The posterior palatal seal:

• Create a border seal to decrease the risk of dislodgement of the denture upon speaking and mastication
• Is created at the anterior periphery of the denture
• A class I palate is the most favorable for denture retention
• The tissue can be displaced several millimeters anterior to the vibrating line
• A class III palate is the most favorable for denture retention

The neutral zone:

• Is recorded in the final impression phase
• Occupies a position of equilibrium among the groups of tongue, cheek and lip muscle
• Is first established in the wax occlusion rim
• It is not a guide for prosthetic teeth position
• It is not a guide for the location of a planned denture’s polished surface

The dentist uses occlusion rims to:

• Determine the supporting areas
• Determine the posterior palatal seal
• Determine all potential denture- bearing tissues
• Determine the neutral zone
• Establish the level of the occlusal plane

A complete denture:

• Has five surfaces
• Has an impression /intaglio surface
• Has a polished surface
• The impression surfaces make contact during functional activities
• The occlusal surfaces don’t contact during functional activities

*The occlusion rim:

• Is frequently contoured labial to the ridge in the anterior region
• Is frequently contoured lingual to the ridge in the anterior region
• Is frequently contoured labial to the ridge in the premolar region
• Is frequently contoured lingual to the ridge in the premolar region
• Is slightly labial to the residual ridge in the molar region

The maxillary rim:

• Is usually parallel to the interpupillary line
• Is usually parallel to the upper lip contour
• Is at height that accommodates the length of the natural tooth plus the amount of bone reduction
• The pattern of bony reduction is ignored
• Doesn’t take into account the interpupillary line

The incisive papilla:

• Appear to occupy a stable locale on the palate
• Clinical and anthropometric measures indicate that the incisal edges of the maxillary central incisors are 8- 10 mm anterior to the center of the incisive papilla
• Clinical and anthropometric measures indicate that the incisal edges of the maxillary central incisors are 4- 5 mm anterior to the center of the incisive papilla
• Doesn’ t have a stable position on the palate
• The papilla location is not used for central incisor positioning