Final Revision Flashcards
SOS
What types of splits do you know? (+explain)
1.soft splints (Made of silicone – Ideally not to be used in severe bruxists as they may wear through it)
2.hard splints: for reversible treatment (Made of acrylic - Ideal option in severe bruxists bruxists bruxists)
-full coverage: design of choice
ex: michigan (upper jaw) /tanner (lower jaw)
-anterior repositioning splint
or
-partial coverage: allow overeruption of non-covered teeth (Should be avoided as teeth may move and overerupt if worn long)
ex: anterior or posterior
they are avoided
ADV Vs DISADV of Soft splints:
ADV:
- for emergencies such as restriction of mouth opening and taking recording compromised so there’s pain
- cheap
- little equipment needed to get it done
- made from a single alginate impression and its resultant cast with no occlusal record
- protective device
DISADV:
- soft is easily chewable so not good at all for bruxists (can make it worse) and increased pain of masticatory muscles due to working harder - (Made of silicone – Ideally not to be used in severe bruxists as they may wear through it)
- can wear down quicker and may need replacement
SOS
What is the role of splints?
- check patient if in RCP
- test if increase in OVD
- treat TMD patients where the pain is of muscle origin
- prevent toothwear before and after restorative care
- check if pts can wear partial dentures, overdentures or onlay dentures
- pt achieves mutually protected occlusion: ICP=RCP
- protect the teeth or prostheses its covering
How long are the splints worn?
- usually at night time but also can be worn all the time
- worn until the pain is relieved, until the tooth wear is addressed by restorative dentistry or until the pt is in an RCP
- can reduce the time they wear it once stress is reduced
Fabrication technique:
- take alginate impressions and mount in RCP on a semi adjustable articulator maybe using Lucia jig. then open the incisal pin on the articulator to allow 2-3 mm clearance on the posterior teeth
- mark the outline of the splint on the cast so that the buccal covers incisal edges and cusp tips of posterior by 2 mm, where as palatal doesn’t cover the whole palate (1 mm)
- wax up the splint to give max even occlusion in ICP
- add canine ramps to give disclusion of all other teeth in lateral movement (posterior not in occlusion in this movement)
- posterior disclusion in protrusion with as many anterior teeth in occlusion as possible
- waxed cast is flasked, packed
- is needed add denture anterior teeth if absent
- a heat cure clear acrylic splint is made
How to check if patient wears the splint?
- lightly blast the occluding surface with 25micron Al2O3 to allow easy marking when checking occlusion in mouth
- leave lightly blasted when pt is dismissed to check working and non-working side interferences in function
- if these areas show as polished when they return: they have worn it, if not then they haven’t had it in
TMJ =
articulation b/w condyle of mandible and squamous portion of temporal bone
SOS
which muscles are involved in the elevation of the mandible?
Medial Pterygoid
Masseter (most powerful)
Temporalis
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which muscles are involved in the depression of the mandible?
Lateral pterygoid (inferior head)
Syprahyoids – digastric, geniohyoid, mylohyoid, stylohyoid
Infrahyoids – sternothyroid, sternohyoid, omohyoid & thyrohyoid
SOS
which muscles are involved in the protrussion of the mandible?
Inferior head of lateral pterygoid
Superficial layer of masseter
Medial pterygoid
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which muscles are involved in the retrusion of the mandible?
Superior head of lateral pterygoid
Deep layer of masseter
Posterior portion of temporalis
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TMJ Dysfunction/Myofascial pain:
Joint associated Problems Vs Muscular Problems:
Joint associated Problems:
- Pain localized to joint (easy to detect)
- Joint noises
- Abnormal/limitation of movement due to internal derangements
Muscular Problems:
- Poorly localized/diffuse pain (not easy to detect))
- No joint noises
- Abnormal/limitation of movement due to muscles
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Aetiology of TMD/ Myofascial pain:
Joint overloading Malocclusion / alteration of occlusion Arthritis Psychological factors Multifactorial Trauma Parafunctional habits
Extend and severity of symptoms UNRELATED to aetiology
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What would be the ideal treatment for a TMD patient?
- Reassurance and Explanation - Counselling alone reduces symptoms
- Conservative management (soft diet, jaw rest, cut food into smaller size)
- Physical therapy (exercises, head, acupuncture, OCCLUSAL THERAPY)
- Cognitive Behavioral Therapy (can help you manage your problems by changing the way you think and behave)
- Medications (NSAIDs, Anti-depressants, Botox) -ibuprofen
- Surgical management
SOS
Enamel fracture:
=
Clinical Finding:
Treatment:
= uncomplicated crown fracture
-Clinical Finding:
loss of enamel with loss of tooth structure, dentin not exposed, no tenderness, no vitality lost
-no sensitivity
-Treatment:
if visible fragment then bond to tooth or contouring of restoration with composite resin depending on the extent and location of fracture
SOS
Enamel – dentin fracture:
Clinical Finding:
Treatment:
-Clinical Finding:
A fracture confined to enamel and dentin with loss of tooth structure, but not exposing the pulp, positive sensibility test
-Treatment:
if visible fragment then bond to tooth or contouring of restoration with composite resin
=> if exposed dentin is w/in 0.5 mm of the pulp, place CAOH base as a liner (on top of the pulp)
-test if there is any pulp involvement; there might be irritation
SOS
Enamel - dentine - pulp fracture:
Clinical Finding:
Treatment:
-Clinical Finding:
A fracture involving enamel and dentin with loss of tooth structure and exposure of the pulp sensitive to stimuli
-Treatment:
CaOH placed on pulp, RCT/pulp capping/pulptomy
=>if visible tooth fragment bond it to the tooth
=>future treatment: crown
SOS
Concussion:
=
Treatment:
=An injury to the tooth - supporting structures without abnormal loosening or displacement of the tooth, but with marked pain to percussion
-tender to touch or tapping
-Treatment: NO
monitor pulpal condition for at least one year
SOS
Subluxation (loosening):
=
Clinical Finding:
Treatment:
= An injury to the tooth - supporting structures resulting in increased mobility, but w/o displacement of the tooth
-Clinical Finding:
tender to touch or tapping
bleeding
-Treatment: NO
flexible splint to stabilize the tooth for patient comfort for 2w
SOS
Extrusion:
=
Clinical Finding:
Treatment:
= Partial displacement of the tooth out of its socket
-Clinical Finding:
elongated, excessive mobile, negative sensibility tests
-Treatment:
reposition tooth by gently reinserting it into socket, stabilize it for 2w, RCT
SOS
Lateral luxation:
=
Clinical Finding:
Treatment:
= Displacement of the tooth in a direction other than axially. Displacement is accompanied by comminution or fracture of either the labial or the palatal/lingual alveolar bone
-Clinical Finding:
displaced in P/L direction, immobile, high metallic (ankylotic) sound on percussion, fracture of alveolar process and loss of vitality
-Treatment:
reposition it with fingers or forceps in original position, stabilize it for 4w using flexible splint, monitor pulpal condition, RCT
SOS
Intrusion (central dislocation):
=
Clinical Finding:
Treatment:
=Axial displacement of the tooth into the alveolar bone. This injury is accompanied by comminution or fracture of the alveolar socket
-Clinical Finding:
immobile, high metallic (ankylotic) sound on percussion, negative sensibility test
Treatment:
allow eruption w/o intervention if it is intruded less than 3 mm, if no movement after 2-4w reposition surgically or orthodontically before ankylosis develops
=>if tooth intruded 3-7 mm reposition surgically or orthodontically
=>if tooth intruded beyond 7 mm reposition surgically
=>pulp will become necrotic in teeth with complete root formation, RCT using temporary filling with CaOH 2-3w after repositioning
=>once intruded tooth has been repositioned surgically/orthodontically, stabilize with a flexible splint for 4w
SOS
Avulsion (exarticulation) and its treatment:
=The tooth is completely displaced out of its socket
-pick it, lick it, stick it (NOT with primary teeth b/c it will lead to ankylosis which will cause problem with permanent teeth later on)
SOS
What are the problems with dentine pins?
- cause stress in the dentine leading to micro cracks (weaken the tooth further), which in turn cause microleakage, then caries. this causes failure of restoration
- do not bond with amalgam alloys or composite
- don’t fill the whole prep depth so a space will be left and bacteria can accumulate
SOS
Nayyar Core:
What is it?
What Materials can be used to fabricate a nayyar core?
Which is the ideal for it?
= a post for posteriors and badly broken down teeth
Materials:
-AMG IDEAL !!!!!
-composite
(NOT GIC)
- needs 2-4 mm coronal GP removal !!!!
- drilling of 4 mm into each remaining RCs with a rose head or GG bur and then all canals and the pulp chamber are packed with AMG or composite and crown built up
- know morphology to built up full contour
- use of rubber dam and matrix
- condensation of AMG into canal orifices
SOS
POST AND CORE:
Dental post Vs Dental core:
Core:
=a substructure, which replaces missing coronal structure and retains the final restoration
-can be placed in any tooth
-composite mostly (bulk)
-if enough natural tooth structure exists that it can be relied upon to securely hold and retain the core, then no post is needed !!
Post:
=a metal or other rigid restorative material placed in the root of a non vital tooth
-helps to anchor the core on the tooth !!
-can only be placed in a tooth that had RCT
-if more than half of a tooth’s original crown portion has been lost, a post is needed to assist in anchoring the core to the tooth
-offers no reinforcement benefit and its placement can weaken a tooth and lead to fracture
-made of metal or metal free carbon fiber posts
-used only when there is insufficient tooth substance
-its width should be established by the width of canal after RCT
-Increasing post diameter in an effort to increase retention is not recommended, as this creates unnecessary weakening of the remaining tooth structure
-post should not be more than 1/3 of the canal width otherwise there is increase chance of fracture
SOS
What is the ideal length for a post?
- post length equal to 3⁄4 of RC length if possible or at least equal to the crown length
- 5 mm of GP should remain apically to maintain an adequate seal
- post should always be subcrestal (under the bone level). if it ends above bone level the higher risk of fracture
SOS
Cast post and core: indirect Vs direct methods:
Indirect method:
-Office: remove temporary filling, preparation and then impression of the post space, adjacent teeth and gingiva is taken
=>light body impression material will be inserted into RC with a specific file: the Lentulo file carrier/ Spillar fillers
-the impression is then used to construct a suitable post in the Lab
-next appointment: fix post and core on tooth
-better
-cast post needed
-sufficient time
Direct method:
- Office: prep and fabrication done in 1 appointment
- a resin pattern is produced by placing a preformed plastic “burnout” post into the post space and a resin material/wax is used to built up the tooth to the proper dimensions
- When this is completed, the pattern post and core is removed from the tooth structure and sent to the lab. The technician will make a duplicate of the post and core using alloys or zirconium
- Cementation: After completion, the lab sends the post and core to the office for the definitive cementation.
- Cast post and cores are cemented inside RCs with dental cement or composite resins. The materials are placed inside RCs with Lentulo files
- more time needed
- the dentist decides how he wants the post, not the lab
conclussion from revision lec:
Indirect: Post and core fabricated in the laboratory (Usually involves the cast post)
Direct: Post and core fabricated chairside Direct: Post and core fabricated chairside (Usually involves fibre composite post and bulk filled composite for the core)
The is also the direct/indirect method where duralay or wax is used to make an exact representation of the post and core system this is send laboratory which is then made into a cast post and core
Rule in prefabricated post and core design:
use the narrowest and longest post possible with a smooth surface because it will decrease the risk of failure
SOS
How to decide which post is the ideal: Direct / Indirect (TIP):
It all comes down to the amount of ferrule present!
2-3 mm ferrule (height): indirect cast post
- impression
- ask the lab to do a post and core in 1
- cement it
≥ 3-4 mm ferrule: direct post
- 1 day appointment
- clinicians preference
For molar teeth its best to consider a Nayyar core instead of a post and core
When sulci are normal (2–3 mm) and healthy and bands of attached gingiva are adequate, margins can be placed up to _ inside the sulcus
0.5 mm
How to restore a tooth fractured at or below the crest of bone? / If biological width is 2 mm and ferrule is 2 mm how much do we need?
room must be created b/w future margin of restoration and bone, 2.5 mm needed to accommodate biologic width and 1.5 mm additional required to have adequate ferrule for the restoration
this means that 4 mm of tooth must be exposed above crest bone to satisfy these requirements
this can be done through bone removal etc
In preparing a root canal for a post, the main barrier against reinfection of the periapical region is:
the endodontic obturation material
- leaving 5 mm of undisturbed apical endodontic obturation material after post preparation
What can influence the long term success of the restoration, after post preparation?
The length of the remaining apical seal
What cannot be considered reliable as abutments for fixed or removable dentures or cantilevers or for patients with severe bruxism and clenching habits?
Extensively damaged teeth
What criteria (in sequence) should be assessed after the treatment plan?
ferrule effect
relation between root and crown length
endodontic condition
Classification of teeth with extensive endodontic damage - Class I:
Ferrule effect:
Remaining root length:
Endodontic condition:
Prognosis:
Ferrule effect: Height of remaining tooth ≥ 2 mm at 4 locations (mesial, distal, buccal, palatal or lingual) and thickness of remaining tooth walls ≥ 2.2 mm for an aesthetic restoration or ≥ 1.6 mm for non-aesthetic restorations
Remaining root length: At least as long as the future crown height plus 5 mm for the apical seal
Endodontic condition: Endodontic treatment may be performed without predictable complications
Prognosis: Good
Classification of teeth with extensive endodontic damage - Class II:
Ferrule effect:
Remaining root length:
Endodontic condition:
Prognosis:
Ferrule effect: Height of remaining tooth 0.5–2.0 mm or Width of remaining tooth walls 1.6–2.2 mm with visible margins or 1.2–1.6 mm with non-visible margins
Remaining root length: Less than crown height plus 5 mm but equal or greater than crown height plus 3 mm
Endodontic condition: Without predictable complications or with uncertain results
Prognosis: Moderate
-A tooth in this class should not be used as an abutment. A new evaluation should be performed after endodontic treatment in cases where pre-treatment prognosis is uncertain.
Classification of teeth with extensive endodontic damage - Class III:
Ferrule effect:
Remaining root length:
Endodontic condition:
Prognosis:
Ferrule effect: Height of remaining tooth < 0.5 mm or Width of remaining tooth wall < 1.2 mm at future margin level
Remaining root length: Less than crown height plus 3 mm
Endodontic condition: With irreversible complications
Prognosis: Poor
-A tooth in this class is not a candidate for treatment; it should be extracted and replaced by a prosthesis
When do classes raise or decrease by 1?
aesthetic concerns: increases by 1
Concern about special stress patterns (bruxism, abutments for a RPD, cantilevers, extensive bridges or secondary abutments): raises the class level from I to II or from II to III
In cases where there is no occlusal issues, the antagonist is a removable denture or small/no loads over the remaining tooth: decreases by 1
For patients with poor OH, uncontrolled periodontal disease or caries, an extensively damaged tooth should be considered Class III
-Pre-prosthetic treatment may affect the initial classification
SOS
Tooth Restorability Index:
- to assess how much tooth structure is left to restore a tooth !!!!!!!!
- provides a structured assessment to evaluate remaining coronal tissue (remaining dentine for retention and resistance)
- 6 equal sextants: 2 proximal, 2 buccal and 2 lingual
- TRI allowed scores: 0-3 in each tooth sextant, with a max score of 18 per tooth !!!!!!
- Disadvantage: Subjective to clinician’s opinion of assessing each sextant
- TRI > or equal to 12: acceptable
- TRI 9-12: questionable
- TRI < 9: unacceptable to retain a plastic core: consider: crown lengthening or cast post and core
0 Tooth Restorability Index:
- None
- 2/3 or more of the tooth sextant there is no axial wall of dentine or any dentine above the finishing line is lacking in height as to be unable to contribute to retention and resistance of a core or crown
1 Tooth Restorability Index:
- Inadequate
- Coronal dentine present in the tooth sextant but, it is insufficient to make predictable contribution to retention and resistance.
- Dentin walls that are less than 1.5 mm thick or more than twice as high as their thinnest part would be included in this category.
2 Tooth Restorability Index:
- Questionable
- More dentine is present than in 1, but in one’s clinical opinion it is not possible to be confident whether or not it will make a predictable contribution to retention and resistance
3 Tooth Restorability Index:
- Adequate
- There is sufficient coronal dentine in terms of thickness, height and distribution that this sextant will contribute fully to retention and resistance of the core and final restoration
What is a veneer?
uses:
= a layer of tooth cover material that is applied to tooth to restore localized or generalized defects and intrinsic discolorations
uses:
- teeth that are stained and can’t be whitened by bleaching
- chipped or worn teeth
- improve the appearance of rotated or misaligned teeth
- uneven spaces or diastemas between teeth
- ability to lengthen anterior teeth
SOS
3 Components of composite resin:
Organic Matrix – a plastic monomer/resin material forms a continuous phase and binds filler particles (via a coupling agent)
INORGANIC filler – reinforcing particles and/or fibres dispersed in the matrix
Coupling agent – bonding agent promotes adhesion between filler and resin matrix
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Filler component in Composites:
Macrofilled Microfilled Hybrid Nanofilled Bulk
