Outcome 6 - Role of DA in fixed prosthodontic procedures Flashcards
How many appointments for Multiple or Complex indirect restorations?
1 - Treatment planning, xrays, study models, treatment options & cost
3 appointments
How many appointments for a single or simple indirect restorations?
1 - Treatment planning, xrays, study models, treatment options & cost
2 appointments
-Preparation appointment
How many appointments for single or simple indirect restorations with CEREC-CAD system?
1 appointment
-treatment planning, xrays, study models, treatment options, and cost
-preparation appointment
-permanent cast cementation
Example of the preparation appointment using traditional methods (not using computer assisted technology - CAD):
Involves removing tooth structure to create space for the prosthesis and ensure retention. The amount of tooth structure removed depends on what type of prosthesis will be placed and what material the prosthesis is made out of
What are the Preparation Steps?
- Topical and local anesthetic is administered
- The shade is determined under natural light (if porcelain or ceramic is to be used)
- Dental assistant obtains impression of the original tooth structure prior to tooth reducution being completed. Impression will be used to make temp coverage at the end of the appointment
- Dental dam / cotton roll isolation is placed.
- Dentist prepares totoh using high speed handpiece and diamond burs.
- The assistant continually maintains a clear operating field with water and air as necessary. Retraction of the cheek, lip or tongue may also be required.
- The dental dam is remoed, and the tooth preparation is assessed for adequate clearance and “draw”.
- A gingival retraction cord is placed.
- The DA prepares materials for the final impression
- The gingival retraction cord is removed from sulcus
- The final impression is obtained
- Temp coverage is prepared and fixed in place to protect the tooth while the lab fabricates restoration/crown/bridge.
- The patient is booked for delivery and cementation in approx one week.
- The dentist will prepare a laboratory prescription to provide the technicians with details for fabrication. The prescription, final impression, bite registration and/or opposing model are placed into a sealed plastic bag to be transported to the laboratory.
What is the purpose of a bite registration/occlusal record?
- To relate the maxillary and mandibular cast correctly
- To place between the cast during trimming and storage to prevent breakage of teeth
-To provide an indication for a special need, when there are problems, such as open bite, crossbite, edentulous areas, end-to-end, or edge-to-edge realations.
What is the purpose of a Face Bow?
A Facebow is an instrument is used to record the relationship between the upper jaw and the rotation axis of the lower jaw, allowing for accurate placement of dental casts on an articulator.
What is an Articulator?
The articulator is a device that simulates the movements of a patient’s jaw. The dental lab will often use these devices to achieve an accurate fit for the prostheses.
They can be simple devices with hinges that simulate only up and down motions, or more complex where they simulate side to side motions as well. A dental assistant can perform this procedure or assist the dentist with the steps.
How long can an interim prosthetic be in place?
Interim prosthetics should be removed within 90 ays of initial placement.
An interim prosthesis is ncessary to:
-Reduce sensitivity and discomfort of the prepared tooth
-Maintain the function and aesthetics of the prepared tooth
-Protect the margins of the preparation
-Prevent shifting of the adjacent or opposing teeth
The procedure for fabricating interim prostheses is often performed in 2 steps:
-Fabricating a Template
Fabricatinng any type of template must be completed prior to tooth reduction
-Fabricating the interim prosthetic (template required to fabricate interim prosthetic)
In order to fabricate an interim prosthesis..
a template or guide must be used to replicate the patient’s original tooth structure. This ensures the prosthesis will have a comfortable fit and occlusion. A template can be fabricated using a variety of methods.
Indirect Template Fabricating Method
Vacuum-Formed Stent using a vacuum former (Sta-Vac machine). Clear stent is made to fabricate a template.
Clear stents have the following advantages:
-Allow easy access and visibility throughout the procedure
-Can serve as a tooth preparation/reduction guide
-Provide a smooth, void-free surface that gives a better finish to the surface of the interim prosthesis
-Can be used with self- or light cured materials
- Inexpensive to produce
Direct / Immediate Template Fabricating Method
An immediate template can be used instead of creating a vacuum-formed stent. This usually require ssome type of impression material and impression tray. Impression of teeth is taken before they are reduced in size in the preparation appointment.
Fabricating an Immediate Template
-An alginate impression can be taken just before the teeth are prepared, kept moist and then used as the template for the provisional material.
- Putty impression material can be mixed and used to create the template of the teeth just before they are prepared
-Softened acrylic buttons can be heated and used to create a template of the teeth.
These techniques can only be used if the original tooth shape is adequate for making an interim crown.
Prefabricated Crowns Methods
-Polycarbonate crown forms (polymer shell)
*Cellulose acetate (thin clear shell)
*Aluminum and tin crowns
-Stainless steel crowns for molars (used mainly with primary teeth)
-Laboratory fabricated crowns (not common)
When does the appointment in which the prosthesis is permanently fixed occur?
The appointment in which the prosthesis is permanently fixed into the patient’s mouth occurs once the dental laboratory returns the case, or once the crown has been created using the computer assisted method. The assistant’s role is to ensure the prosthesis is on site at least one day prior to the patient’s appointment
Appointment Steps for inserting Permanent/Fixed Prosthesis
- The patient is seated, medical and dental history is updated. Discuss with patient any issues while wearing interim restoration.
- Patient is anaesthetised if deemed necessary.
3.The provisional crown or restoration is removed and kept until the end of the appointment.
-Dental assistant removes provisional crown using either PFI with finger pressure or plyers (Howe players are common) gentle pressure is applied.
-Dental assistant cleans prepared teeth from temporary cement residue using explorer. Moist cotton pallet can be used to aid in clean up. All temporary cement must be removed from the prepared tooth. The tooth is then thoroughly cleaned and dried.
-Dental assistant notifies the dentist that patient is ready for permanent prosthetic try in.
- The fixed prosthetic is disinfected then placed onto the prepared tooth for “try in”.
- Adjustments are made as necessary. If the prosthetic cannot be satisfactorily adjusted within the office, it may be necessary to take a new impression and re-fabricate the prosthetic.
- When the prosthetic is satisfactory to the dentist and patient, preparations are made for final cementation.
7.The area is isolated to maintain a dry field.
- The assistant prepares the permanent luting cement or bonding system and applies it to the inner surface of the prosthetic.
- The dentist seats the prosthetic. The patient may be asked to assist with the seating by applying force to the prosthetic via a bite stick or cotton roll. The dentist ensures seating is ideal using the mirror and explorer to assess the margins.
-The patient applies biting pressure to ensure there is no movement until the cement/bonding system reaches initial set. - Dental assistant role is to monitor the setting time of the cement used. Once the permanent cement has completely set, the excess cement is removed from all areas and isolation is removed.
- Dental assistant confirms with patient the correct fit is obtain, dentist completes final check
- Dental assistant provides patient with written and verbal post-operative instructions.
- Treatment rendered is completed.
What does the Dentist Assess when the fixed prosthesis is placed on the prepared tooth for the “try in”:
Marginal fit with an explorer and mirror
Contacts using dental floss
Occlusion with articulating paper
Esthetics with the patient’s participation
What are the Post-Op instructions given to patient after fixed/permanent prosthesis is placed?
-Local Anesthetic precautions
-Cement may take a few more hours to set (Avoid sticky foods for rest of day)
-Tooth may be sensitive to hot and cold for a few days - but it should improve
-Please call office if the bite does not feel right once freezing wears off
-Brush and floss normally
IPC Standards to be followed in fixed prosthodontic procedures
Before handling contaminated materials (dental impressions for example) dental assistant must perform cleaning (rinse item under cool running water) and disinfection before performing any clinical activity.
Below should be followed when applicable:
-Wear PPE determined in a point-of-care risk assessment.
-Clean thoroughly to remove all body fluids (e.g., blood, saliva) prior to disinfecting.
-Rinse thoroughly to remove all residual traces of disinfectant.
-Dispose of single-use shipping materials (e.g., plastic bags).
-Disinfect/sterilize, according to reprocessing policy if reusable shipping materials (e.g., reusable plastic containers)
-Devices included with a case are placed into a clean impervious bag (and recorded to prevent loss and maintained in the lab case box) until returned to the dental office.
Why are post-operative insntructios important for prosthodontics?
Post- operative instructions are very important to ensure that the patient takes adequate precautions to avoid injury to soft tissues or fracturing the new restoration.
Post-Operative Instructions for the Preparation Appointment
-Approximately how long numbness from the local anesthetic is expected to remain, and a reminder to avoid hot liquids/foods, biting on effected tissue.
-Address tissue retraction and/or possible sensitivity pending materials used (cord placement, electrosurge or retraction paste)
-Caring for temporary restoration. Explain the temporary material properties, discuss food choices; foods to avoid when eating (hard, sticky)
-Demonstrate flossing technique. Demonstrate flossing technique, show patient to pull floss through, with the bridge demonstrate flossing under embrasures.
-Sensitivity may be present to hot and cold for several days, but should decrease over time. If any pain to pressure, heat or if you wake up at night call the office as soon as possible.
-If the temporary, breaks or comes off before your next appointment – please call the office to schedule another appointment to have temporary coverage placed again.
-Advise patient that the temporary restoration should not stay in the mouth for longer than 90 days.
Post-Operative Instructions for Insert/Delivery Appointment
-Approximately how long numbness from the local anesthetic is expected to remain, and a reminder to avoid hot liquids/foods, biting on effected tissue.
-Patient can eat and drink right away if local anesthetic is not given.
-Follow permanent cement manufacture for complete setting times (some permanent cements may take 24 hours to fully set)
-Review/demonstrate flossing and brushing technique.
-It is a permanent restoration and will still require care and routine check-ups.
-Any pain to pressure, heat or if you wake up at night call the office.
-Show patient the restoration in the mirror.
-Complete treatment rendered, include if the patient is happy with the outcome.
