Restorations of root filled teet Flashcards
What are the broad options we have when a tooth has pulpal disease
- Extraction
- RCT
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 (XLA, Overdenture abutment)
- There may be sufficient tissue for a direct restoration
3, Greater tooth loss but ferrule is possible (indirect restoration needed)
What Is the ferrule of a root treated tooth
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 crown 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 remaining 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 remain gin 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 the tooth be low or high during function
What is the rationale for restoring ga root filled tooth
- To provide a biological seal to prevent re infection of the root canal system
- To protect raining tooth tissue
- To maintain occlusal stability and proximal contacts to prevent over eruption or drifting
If a patient has sufficient tooth tissue on their root filled tooth 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 cover the GP with when placing a direct plastic restoration
- RMGIC
- 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
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
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 of dentine
- Can be used 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 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
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 will fracture
Give some advantages of a cast post and core
Can go sub gingival
good 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
- Better aesthetics
- Reduced number of stages therefore less discrepancies
Give some disadvantages of a prefabricated post
long appt
Are anterior or posterior teeth at greater risk fo fracturing
Posterior
How do we try and reduce the likelihood of fracture in posterior teeth
BY using cuspal coverage
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?
- § from the drill
- Poor coronal seal
- Root fracture
- Fractured post
What will happen if a good coronal seal is not achieved
Reinfection of the root canal can occur
