Lecture 2 Flashcards
what is important to tell the patient went making a denture
Let them know the shortcominges
what are the characteristics of an Ideal MAxillary ridge
Abundant keratinized attached tissue Square arch form Firm, broad and tall residual ridges Moderate Palatal vault Low frena attachments
what are the characteritisc of an ideal mandibular ridge
Well-defined retromolar pad abundant attached keratinized mucosa Firm, braod and tall residual ridges Deep retromylohyoid space Low frena attachments
what is the problem with high frena attachments
will pull denture away
what can be done if you have poor retentive features in a patient for a denture
Place implants to aid in holding
what do you tell paitent to do when selecting an edentulous stock stray
Direct patient to pucker and smile after seating tray and alginate
- then relax while material sets
where should a maxillary edentulous stock tray extend
Beyond the pterygomaxillary (hamular) notch and vibrating line onto the soft palate
what do you tell the pateient to do when selecting a mandibular edentulous stock tray
Have patient protrude tongue and touch upper lip while material sets
what must a mandubular impression tray cover
Retromolar pads
extend to capture retromylohyoid fossa
how should a well-made preliminary impression lok
must have proper border extensions and all relevent anatomy captured
Diagnostic cast requirements
4-5mm land area
2-3mm deth of peripheral roll
15mm thickness
why should a diagnositic cast be a certain thickness
To avoid breaking
what is a custom impression tray
An individualized tray specific to eachpatient used for final impression purposes
what is the purpose of a custom tray
- Minimize impression material distortion (uniform thickness= accuracy
- Prevent tissue distortion (less viscous material = more accurately adapted tray)
- allow for accuracy by molding the borders resulting in better retention
how should a custom impression tray be addapted
to the contours of the preliminary cast with the borders approximating the outline of the complete denture
what is the goal of border molding
Allows for formation of the peripheral seal
what does a custom impression tray need to capture
Borders and movements
how far should a Custom tray go into the vestibule
2-3 mm short of the dept of the vestibule
goal of wax thickness for a custom tray
minimal wax thickness
how thick should a custom tray be
2-3mm tray thickness
how should the handle be shapped
45 degree handle
- not impinge on the vestible or distort the lipd
presence of finger rests on custom impression trays
on the 1st molar and 2nd premolar as to not distort the vestibule when border molding and making the mandibular final impression
how many layers of wax should be used on edentuous patients
1 layer just short of the vestible
why leave tray 2-3mm above the vestible
to allow for movements
what is the purpose of the wax spacer
Provide room for the impression material and ensure a consistently repeatable positioning during tray placement
what is the problem with a too large handle
Can hurt border molding
what is the other way of providing tray relief
Placing stops in the custom tray
maxilla: posterior alveolar ridge
Mandible: buccal shelves and posterior alveolar ridge
how many layers of triad tray material should you use
1 layer
size of the handle
9mm height
10mm wide
- a small roll of material over the incisive papila region
why place stops on mandibular trays
hold the tray inplace when border molding
should the wax spacer be melted
No
what is the advantage of using a wax spacer/tissue stop
- creates tissue relief for impression material
- center and stabilize the tray on an edentulous ridge
- clinician has predictable positing on tray reinsertion to prevent over seating during border molding
should wax come all the way to edge of the custom tray
no, 2mm away from the edge of the custom tray
why shouldn’t wax come all the way to the edge of the custom tray
allow for border molding amterial to overlap the edge o the tray and form a U shaped joint
-holds the impression material in tray
how should a custom impression tray look
No shap edges
Tray is stable on preliminary cast
Flat edges of tray
Uniform tray and wax spacer thickness
should a tray touch the depth of the vestible
No
what should the first border molding account for
The movements of the mouth
