4. Class IV and Diastema Flashcards
Definition
It is a lesion that
involves the proximal surfaces of ____ teeth and includes the loss of at least one of the ____
anterior
incisal angles
Preliminaries
*____
*Examination
*____ evaluation
*____
To reveal the full extent of the lesion, proximity to the pulp, and condition of the pulp and surrounding structures
Hot/cold stimulus (how long)
◦If none, is ____ dead?
◦Think about stresses and ____ that might put pressure on the tooth
History Radiographic evaluation diagnostic models pulp strain
ETIOLOGY
Trauma
Especially ____ and young adults
Are usually more ____ than vertical
Caries
Frequently carious Class ____ which has undermined ____ edge, usually ____
Defective restorations Usually ____
7-8 year old patient
• some dentin is exposed
◦Anytime take a ____ in feels pain
children
horizontal
III
incisal
vertical
vertical
breath
Objectives
- To protect remaining dental and pulpal ____
- To re-establish ____
- To provide a ____ treatment to restore involved teeth
Main purpose of incisal edge
• ____ tooth
• ____
tissues
aesthetics
conservative
incise
phonetics (speech)
*Sometimes composite resin restoration is placed as an ____ treatment while determining prognosis of tooth prior to definitive restoration
interim
Preparation
● 3 methods of retention
____
● grooves in ____ or
other shaped undercuts
● ____ or pins
Micro-enamel
● Requires a wider more substantial ____
- etching of the ____ - getting a nice good bond
● ____
- the bonding procedure
macrodentinal
dentin
dovetail
bevel
enamel
microdentinal
Incisal and gingival retention grooves and dovetail extension
– dovetail enhances ____ and retention, but is less ____ and not used often
– Pins are avoided in ____ preparations as there is a risk of ____ or may corrode and shine through thin areas of ____
strength conservative anterior perforation enamel
Preparation
____mm wide bevel for esthetic ____ and increased ____ through acid-etch bonding
The bevel is of UPMOST IMPORTANT
• Much wider 2-3 mm
• GET EVERY BIT YOU CAN!!!!
2-3
blending
retention
Occlusal Assessment May Influence :-
a) ____ of outline
b) ____ form
c) ____ form
d) position of margins which should not be in ____ areas - Want to keep them as ____ away as possible
e) Remember the restoration is going to be subject to downward,
upward, lateral , oblique, rotational and shearing forces
Just goes t show that we have come so far in the bonding procedure Pressure of a human bite: • Anterior ◦\_\_\_\_ lbs/in2 • Posterior ◦\_\_\_\_ lbs/in2
extension retention resistance stress far 57 171
Shade selection
– prior to ____ and placement of rubber dam
- more difficult if ____ restoration without normal ____ coloration
- ____, if necessary
dehydration
large
dentin
prewedge
Beveled Conventional Preparation
Outline form
– preparation walls are as ____ or ____ to long axis of tooth as possible
Results in design to provide greater ____ to biting forces
These days great emphasis
is placed on minimally ____ preparations
Remember you want to take away as little
____ as you possibly can
perpendicular parallel resistance invasive enamel
Outline form
Carbide or diamond bur on high speed
Remove all weakened ____ - In weakened enamel is
____ ENAMEL
Excavate infected ____ Using round bur on slow speed - or ____
Aim for a smooth flowing outline
enamel
decalcified
dnetin
spoon excavator 9
BEVEL
Cavosurfaces of all accessible enamel margins are beveled with ____-shaped diamond
– ____ degree angle
– approximately ____mm
– ____ thickness of enamel
flame
45
2-3
1/2
BEVEL
● Bevel may be ____ for additional retention and esthetics
- For additional enamel to bevel
- Opens up more of the ____ where the bonding can enter
Scalloping > • \_\_\_\_ purpose ◦If use a straight line ◦You may be able to see where the lesion ends and where the tooth starts
scalloped
canals
esthetic
Procedure
● Retention form
– ____ bonding to enamel and dentin
– additional retention achieved by increasing width of enamel ____ or placing ____
micromechanical
bevels
undercuts
Retention form
Pits and / or grooves
– Using a 1/4 round bur, prepare a groove bisecting the junction of ____ wall and ____ wall and extend length of ____ floor
- At inciso- axial line angle, more in the nature of a ____ than a groove
Up until this point the patient wouldn’t even need an anesthetic
• this is where they start to feel ____
axial
gingival
gingival
pit
pain
Minor Traumatic Fracture
Little or no preparation other than ____ the surfaces in the area of the fracture
● Remove any existing ____ or ____ restorations
● Prepare outline form to include ____, friable enamel
● ____ mm bevel on all available cavo-surfaces
roughening lesions defective weakened 2
Clinical Considerations
● A ____ can be created when the incisal edge is missing and the internal layer of dentin is exposed
– create with small ____
– enamel rods must be supported by ____
retentive trough
inverted cone
dentin
Clinical Considerations
Trough is carried directly into ____ portion of preparation
● ____ cone
● ____mm in depth
• Cut a little grove in the dentin
• But must have remaining ____ on either side
◦This would leave unsupported enamel ◦Enamel rods must be supported by ____
proximal 33 1/2 inverted 1-2 dentin dentin
PROBLEMS??
MECHANICAL STABILITY,- - -which is dependent on the ____ of the material, and it’s ability to resist ____ and fracture
Without this mechanical stability, cracks develop in the restoration, and with propagation of these cracks, may lead to ____ of the restoration
AESTHETICS
The ____ bevel does not allow for sufficient layering to achieve the desired aesthetic result
strength
wear
dislodgement
shallow
Research showed that if the finish line was in the form of a ____, mechanical stability was significantly improved.
The increased space that a chamfer affords, allows for the placement of additional ____ to achieve the desired aesthetic result.
A chamfer finish line on the ____, where most of the ____ is centered, could be an improvement in the design of the prep
chamfer
layers
lingual
stress
What constitutes a beautiful smile?
GOLDEN PROPORTION
Width of ____ is in direct proportion to the width of the ____ and that part of the ____ that shows from the front
The central incisor width length = length of lateral plus ____ portion of canine!
central incisor
lateral incisor
canine
medial
Preliminary Steps
- Determine the Shade of the tooth taking into consideration the following:-
a) The ____, Chroma, and the ____ of the shade
b) No ____ monochromatic shade can mimic the combination of shades that make up the natural
dentition. Teeth are ____.
c) The ____ features of the restoration are somewhat more important than establishing the exact shade - Dark ____
- Incisal ____
- Middle area ____
____: actual color
____: depth of color
____: darkness or lightness
Composite has a ____ effect, takes on color around it t some level
hue value single polychromatic anatomical
cervical
translucent
lighter
hue
chroma
value
chameleon
Class IV Restoration
● Etching, priming, adhesive placement same as Class ____
– place ____ prior to etching to protect adjacent teeth
– Etch beyond ____
III
matrix
bevel
Matrix Application
Place polyester ____ strip and ____ gingivally
Control of matrix strip is difficult and may cause:-
1, Over or under-____ restoration or over-____ of the strip
2, Open ____ point
3, Extrusion of material ____
Need to pull the strip at an ____ so the incisal edge is formed
• but it is quite difficult
matrix wedge contoured angulation contact incisally
angle
Wedging
● Seal ____ margin
● ____ teeth
● Ensure ____ contact
● Push ____ and proximal tissue gingivally to open gingival embrasure
gingival
separate
proximal
rubber dam
Placement
Composite available in 2 forms:-
1, Bulk syringes where the ____ benefit is better, but ____ is more difficult
2, Unit dose ampoules which allow direct injection of material into the preparation. This minimizes entrapping ____, better control of ____ as they are discarded after use
cost
handling
air bubbles
infection
A Dental Composite is:-
A ____ material with a combination of different components bonded together in a ____ base, each of which maintains their original ____ and ____
multiphase
resin
identities
properties
