Restoration of root filled teeth 1 Flashcards
What are the broad options we have when a tooth has pulpal disease?
- Extraction
2. Consider Endodontic treatment
Hw do we determine a treatment lan when considering endodontic treatment?
By doing a pre op assessments
What different things might we conclude after carrying out pre op treatment
- There may be insufficient tooth tissue for strength or to create a ferrule
- There may be sufficient tissue for a direct restoration
3, Greater tooth loss but ferrule is possible (indirect restoration needed)
If a patient has insufficient tooth tissue what are our treatment options
- Overdenture abutment
2. Extraction
What is the ferrule in a root treated tooth?
It is the portion of the crown that encircles the remaining dentine
Why is the ferrule important?
As it binds to the remaining portion of the tooth and prevents the root from fracturing and the down from dislodging
State the ideal dimensions of the ferrule
Height: 2mm
Width: at least 1mm
(ideally should be encircling the tooth )
Name the 3 assessments you carry out when checking a root filled tooth
- Endodontic assessment
- Periodontal assessment
- Coronal tissue assessment
How should you cary out a coronal tissue assessment?
- Remove any existing restorations to evaluate remaining tooth tissue
- Then evaluate aesthetics
- Evaluate occlusions
When evaluating resining tooth tissue what should you focus on?
- Quality of the remaining healthy tissue
- Min height of ferrule should be 0.5-2mm
- Thickness of tooth tissue
- Portion of remaining healthy tooth tissue
When evaluating aesthetics during coronal tissue assessment what do we look at?
1, Tooth/ root discolouration
2. Tooth shape
When evaluating occlusion during coronal tissue assessment what do we look at?
- Is the tooth in occlusion
- Does the tooth contribute to lateral or protrusive guidance
- Will the forces on he tooth be low or high during function
What is the rationale for restoring a root filled tooth
- To provide a biological seal (coronal seal)to prevent refection of the root canal system
- To protect remaining tooth tissue
- TO maintain occlusal stability and proximal contacts to prevent over eruption or drifting
4 TO RESTORE FUNCITON
If a patient has sufficient tooth tissue what are our treatment options
Restore with composite of amalgam with weak cusps reduced and onlayed
If a patient has greater tooth tissue loss but ferrule possible what are our treatment options
- Direct amalgam or composite core followed by preparation for an indirect restoration (crown or onlay)
- IF the core requires additional retention and support we need a post
What can we use to cover the GP when placing a direct plastic restoration?
- RM-GIC
2. Flowable resin core
Name the type of core we can put in if a post is NOT required
The Nayyar core
How do we place a Nayyar core?
- Remove 2-4mm of Gp
- Place a thin layer of RM-GIC over the GP
- Finish with amalgam or composite
Name the different types of posts we can use
- Prefabricated posts
2. Cast post and core
Why do we use posts?
They are only used to retain the core
What are the problems associated with using posts?
Posts weaken teeth and can cause perforations
Which type of poss should we avoid?
Threaded posts
What are the requirements and indications of using a post
- Post `length should be at leat equal to coral length with enough apical seal
- The presence of a 1.5-2mm ferrule is important for fracture resistance
How do we put in a pre fabricated post?
- Use gates glide to remove GP
2. Use parapets drilled to prepare post channel (Just need to make enough space to put the post in)
What are the benefits of a pre fabricated post?
- Aesthetic as they are metal free
- They bond with dullard self cure resin cements and composite core material
- Felxural properties closer to those o dentine
- Can bereaved for revision of endodontic treatment
- Claim to reinforce root
- The post is more likely to fracture than the root so you can save the tooth
What are the steps involved in making a cast post?
- A pos Chanel is prepared in the tooth and then a plastic impression post is used along with silicon impression material to record the shape of the post space within the canal
- A post is cast along with the core in the LAB and this angle unit is cemented into tooth on another visit
- This means you’ll need a temporary post and core between appointments
What are the guidelines for post lengths
Ideally:
- The post should in the root(which is supported by bone) as much as possible
- The post length in the bone should be at last as much as that above the boney crest level
- There should 4-5mm of apical GP remaining
What will happen if stress distribution is not equal in the post and root?
Root fracture will occur
Describe the ideal post diameter
Retain as much coronal and radicular dentine as possible
What can happen if the post diameter is too narrow?
Post may bend or fracture
What can happen if the post diameter is too wide?
Root fracture
Give some advantages of a cast post and core
- Can go subgingivally
2. Goof if the canal is oval
Give some disadvantages of a cast post and core
- Extra clinical visits requires
- Greater likelihood of discrepancies due to impressions, casting models
- Temporisation difficult as need a coronal seal
Give some advantages f prefabricated posts
- Immediate coronal seal
- Crown prep can be done at th same visit
- Beter aesthetics
- Reduced number of stages therefore less discrepancies
Give some disadvantages of a prefabricated post
The core takes time to build
Whihv teeth are at a greater risk of fracture:
Anterior or posterior?
Posterior
How do we try and reduce the likelihood of fracture in posterior teeth?
By using cusp protection
Gives some options for cusp protection
- Extra coronal restorations
- Inlays/ onlays
- Full coverage crown
State the occlusal guidelines in place when carrying out restorations on root filled teeth
- Post crowned canines should not provide canine guidance
- Post crowned posterior teeth should have ICP contact only
- Post crowned anterior teeth should have incised guidance shared across all anterior teeth
How can root filled restoration fail?
- Perforations from drill
- Poor coronal seal
- Root fracture
- Fractured post g
What will happen if a good coronal seal is not achieved
Reinfection of the root canal can occur
