class III and V sensitivity Flashcards
class II pre-preparation
- clean the tooth
-pumice slurry
-consepsis: CHX, no emollients that would affect bond
shade selction
before placing rubber dam
-dehydrated tooth affects shade
-avoid shining light on tooth
at least 3 color esthetic zones on a tooth so
take shade from portion of shade guide most similar to thickness of restoration
shades
gingival:
middle:
incisal:
gingival: opaque
middle: blend of incisal and gingival
incisal: transulcent
class III prep occlusion
mark occlusion prior to applying dam
-avoid margins ending in occlusal contact areas
class III ___shaped preparations
wedge
where are caries in class III
usually more lingual than facial
gingival to contact area
approach from where when possible
lingual
to improve esthetics such as discoloration and deterioration less visible, color match easier and facial enamel is conserved when
may be acceptable to leave unsupported enamel on facial and incisal wall of preparation
preserve this contact in class II
incisal contact
-may be acceptable to leave sound enamel here NO HOOKS
begin outline form by preparing
PERPENDICULAR TO LONG AXIS
inciso-gingival height
1.5 on maxillary lateral
2.0 on maxillary central
this contact is broken:
this contact is intact:
this contact is MINIMALLY broken:
broken= gingival
intact= incisal
minimally= facial
mesio-distal width
1.5mm
is retention required?
not always
place prep in _____, do not undermine enamel
dentin
incisal point place with ______
1/2 or 1/4 round bur
gingival groove place with
1/2 or 1/4 round bur
place retention deeper than normal, but avoid placing retention to avoid
pulp exposure
class III bevel
place 1mm bevel lingual (or facial)
45 degrees
smooth and even
flame-shaped diamond bur
root surface caries:
same prep but DO NOT BEVEL on dentin or cementum
do not bevel when
if there would be heavy centric contact on margin
-enamel wears better than composite
-enamel is stronger than composite
can use this for added retention when not beveling
dovetail lock
class III facial approach
- when lingual access may involve only centric contact of tooth
- irregular tooth alignment or rotation
- extensive caries on facial
- existing defective restoration on the facial
class V prep
carious lesion in gingival third of tooth
can be buccal or lingual
class V pre-prep
- clean tooth
- select shade
isolation in class V rare instance
where it may be appropriate to use 212 clamp
curing light
-light must have sufficient output(for all composite resins)
>550mW/cm^2
depending on composite
-darker shades need longer curing time or smaller increments
class V prep
axial wall
M and D walls
incisal gingival height
axial depth
- axial wall convex
- mesial and distal walls diverged
- incisal gingival height= 1.5mm
axial depth=1.0mm
class V prep bevel
- use diamonds
- increases surface area
- increases retention
- reduces microleakage
-reduces margin discoloration
-eliminates white halo effect=better esthetics - bevel ENDS of enamel rods
- add retention grooves
when not to bevel with class V
below CEJ
-not in cementum
class V restorations may extend onto the root surface.
polymerization shrinkage is greater than bond to cementum/dentin
this can cause
contraction gap
this can minimize contraction gap
retention groove
this restorative material can reduce microleakage
RMGI
and amalgam
non carious cervical lesions
- abrasion- wear (toothbrush, pen chewing)
- erosion- caused by acid (gerd)
- abfraction- mechanical loss of tooth structure (loading forces in wrong spot= flexure of tooth and failure of enamel and dentin)
bond strength to natural sclerotic dentin is ____% lower than sound to cervical dentin- REMOVE with bur
25-40%
erosion
discuss diet (soda drinkers)
discuss medical history (acid reflux, dry mouth, bulimia)
flexure and fatigue of enamel and dentin
abfraction
caused by occlusal forces
-microfractures
-heavy occlusal force in lateral or eccentric occlusion
-stress is concentrated at cerical area of tooth causing fractures
abfraction
when to treat non-carious cervical lesions
- lesion is deep enough to compromise tooth
- sensitivity
-attempt non-surgical first - involved in partial denture design
- defect in approaching pulp
- defect contributes to periodontal problem
-overcontoured restorations more likely to produce perio problems
for abrasion:
conservative extension
may need minimal to no prep
pain caused by dentinal fluid movement
-from mechanical or chemical stimuli
-temp changes
-air drying
-osmotic pressure
hydrodynamic theory of dentin sensitivity (fluid-filled tubules)
7 causes of tooth sensitivity
- caries or leaky restoration
- void-fluid flows into void (from CaOH liner having washed away)
- premature occlusion
- exposed dentin (recession or incomplete formation of CEJ)
- exposed cementum
- post-perio surgery
- abrasion and erosion (includes iatrogenic from polishing instruments)
treatment options for sensitivity
- aim is to occlude tubules to stop fluid movement
- NONINVASIVE FIRST
-topical fluoride
-desensitizing dentifrices (toothpastes)
-potassium nitrate in OTC
-prevident 5000 sensitive (prescription) - desensitizing agents
-gluma - if none of that works, restoration
sticky, yellow semi-liquid containing 5% NaF in a resin base mixed with alcohol to dry quickly after application
fluoride varnish
with fluoride varnish, when can patient eat/drink and brush
eat and drink after
avoid hot food or sticky food
avoid brushing for at least 6 hours
this desensitizing dentrifices toothpaste may take 1-3 months for results to be realized
Sensodyne (block drug company) strongtium chloride 10% and POTASSIUM NITRATE (KNO-gunpowder)
this is placed by dentist when preparing tooth
-placed after etching for composite
-lightly dry
-place bond
-place composite
gluma (desensitizer)
dentin hypersensitivity when
cracked tooth
treatment for sens in class V lesions
when to restore vs when to leave
esthetic desire of pt
lesion >1.0mm depth and progressing
possible pulp exposure
structural integrity of tooth is threatened
treatment for restoration that will block tubules
amalgam
composite
glass ionomer
treatments why they work
- protein coagulation
- enzyme interference, blocking nerve impulses
- induction of tertiary dentin
- *various precipitates in dentinal tubules block fluid movement
- destruction of odontoblasts
- placebo effect
