1. Direct posterior restorations Flashcards
LOs
(recommend listen to this lecture + so learning with indirect lecture PPT????)
(when you assess patient you assess them as a whole - hence need to have knowledge about direct and indirect posterior restorations and put it all together to help you make decisions)
WOULD RECOMMEND READING SPECIAL EDITION OF BDJ (MONTH OCT 2020), THIS IS 2ND EDITION + ALSO 1ST EDITION IN CONJUNCTION WITH THESE SLIDES FOR MORE INFO
Conditions causing tooth loss
- Caries
- Tooth wear
- Developmental/genetic disorders
(EG immunogenesis imperfecta) - Trauma
(uncommon on posterior teeth)
Reasons for restoring teeth?
Just because there is some tooth tissue loss, does not mean a restoration is always needed
- Facilitate plaque removal and restore a cleansable tooth surface
- Restore appearance
- Restore form, function and structural integrity of the tooth (Eg stop tooth from fracturing further)
- Arrest carious process
- Prevent pain
- Protect the pulp
- Prevent drifting/tilting if contact point is lost (+perhaps overeruption of other teeth)
How do we make the decision about whether to perform a restoration or not? what factors do we look at?
- How extensive is the lesion?
- Is it in enamel, at the EDJ or into dentine?
- Caries risk assessment of the patient? (care planning clinics)
- How likely is it for the carious lesion to progress?
- Is the cavity cleansable?
MI techniques?
they preserve tooth tissue as much as possible
aim of care plan is to send patient home with a care plan that will help reduce further diseases is possible
- Prevention – OHI/Diet/Topical Fluoride
- Facilitating OH and decreased plaque accumulation
- Silver Diamide Fluoride
- Atraumatic restorative techniques
- Chemo-mechanical caries removal
- Modern materials
WOULD RECOMMEND READING SPECIAL EDITION OF BDJ (MONTH OCT 2020), THIS IS 2ND EDITION + ALSO 1ST EDITION IN CONJUNCTION WITH THESE SLIDES FOR MORE INFO
direct Vs indirect restorations
DIRECT:
Restorations placed in cavity directly by dentist
Material sets after placement in the cavity
INDIRECT:
Impression taken from cavity, sent to the lab
Restoration is made in the Lab and then cemented inthe mouth
Why does it matter???
- to choose which restoration is suitable for that particular cavity
- it affects some of your cavity designs
1
what is extra coronal restorations?
2
is it usually direct or indirect?
1
- restorations that cover surface of tooth and cusps
2
- indirect
- usu made in labs
intra coronal restorations
is it usually direct or indirect?
can be:
- direct
- indirect
Direct Vs indirect preps
*How would the cavity design be different?
(EG if doing MOD restoration if that was a direct or indirect restoration how would the cavity design differ?)
- if you’re doing a direct restoration, the restoration sets in the tooth
- hence the cavity design should have the appropriate measures to retain that restoration in the tooth
- in terms of retention in various cavities, what we look at is undercut, angulations of the walls, etc
- in direct restorations we would need to prepare the walls at an undercuts to increase the retention
- if we prepared an indirect restorations with walls at an undercuts the restoration would not fit as it’s been made in a lab and will then be placed and cemented in the patient
- this is because the bottom part of the restoration that sits on the floor of the cavity would be wider than the top hence it would not fit in as it’s solid
HENCE we need to design differently for indirect restorations
- for indirect restorations we may make the walls parallel and slightly wider at the top of the restorations
- this is because the restoration is cemented in, and you want the excess cement to come out, hence that will ensure the seating of the restoration is more accurate
DIRECT RESTORATION basic principles/ steps of cavity preparation
*Access caries
*Remove caries
*Decide whether restoration or direct/indirect pulp cap or root treatment
(type of restoration material needed)
- Look at the cavity
- Decide which material/materials are to be used
- Is there a need for lining
- Adjust cavity so it is suitable for the materials to be used
how do we access caries?
- Through enamel or existing restoration
- As conservative as possible but providing adequate access to remove the amount of caries you think is necessary
Direct restoration
where would we remove caries from?
- EDJ and walls first
- Floor (usu roof of the pulp)
why is caries removed from the EDJ and walls before the floor?
so that most of the bacteria are
removed before going anywhere near
the pulp to decrease the risk of bacterial
contamination of the pulp
Does all caries need to be removed from the EDJ + walls of the cavity?
WHY?
- varying opinions
- we want to preserve as much tooth tissue however sometimes we are less conservative in these 2 areas compared to the floor of the cavity
BECAUSE - as stained carious tissue may causes an aesthetic issue (especially for anterior teeth)
- do we have a good enough seal on our materials as we are the surface layer (can we get leakage and will that caries progress faster)
- we are moving more towards preservation and less tooth removal
Does all caries need to be removed from the floor of the cavity?
WHY?
- for the floor of the mouth there is a general consensus that for the floor of the cavity (roof of pulp), infected dentine is removed and affected dentine (hard stained dentine) can be left to stay over the pulp
- this is because we are trying to remove the bulk of the bacteria and be as conservative as possible and avoid the pulpal exposure
when we decide how much caries to remove from the EDJ, walls of cavity and floor of mouth what factors do we need to consider?
how much caries do we remove from the EDJ and walls of the cavity?
*All soft caries must be removed
*Different views in different situations on removal of stained but hard dentine in this area
- Stained dentine may have to be removed if it is likely to show through enamel
how much caries do we remove from over the pulp?
What would we do in this situation?
- in a situation like this which is an exposure
- we would only put lining directly over the exposure and not over the rest of the cavity
- and try and ensure a good seal for the restoration
Why do we need adhesion?
- Resin infiltration with e.g. HEMA
- to form hybrid zone
- have various bonding systems
- most important thing is to know what system you are using + the steps for using that particular bonding system
Possible sites for cavities?
Pits and fissures - Occlusal/ Class I
Approximal - Class II
Smooth surface - Cervical/Buccal/Palatal/
Class V
- resin composite has improved
- structure has changes + improved
- one of the most common restoration materials for posterior teeth
(nothing said in voiceover)
Common restorations
(nothing said in voiceover)
NEXT FCs are just pictures of different cavity preparations and restorations (DELETE???)
