Midterm - Composite Flashcards
(32 cards)
Polymerization/Curing
setting and hardening, doubles bonds to single bonds
Degree of Conversion
measure of the extent of polymerization, the % of C=C bonds into single bonds
Activation
initiating curing
Autocure
a chemical reaction started by mixing two components
Photocure
light activated (a single component) - UV, visible light cure
Dual Cure
starts with photo cure, completes with chemical autocure
Without Silane Coupling Agent
lack of bonding between filler/matrix, easy separation, leakage, decreases fracture, fatigue, wear resistance
Silane Chemistry
reacts to filler via alkyoxysilane groups (Si-O-Si)
reacts with itself to form siloxane
reacts with methacrylate groups in resin
Light Activation Peak
peak intensity between 450-490nm
Risks of Inadequately Cured Resins
allergen leaching
increased marginal breakdown
increased secondary decay
Dual Cure: One Component Systems
one paste, initial cures by photo cure, finishes with autocure
no mixing
Dual Cure: Two Component Systems
two pastes, base paste can be light cured only, activator allows for chemical curing
bulk filling, remote areas inaccessible to light cure
Total Retentive Force
retention power, depends on the cavity surfaces in bonding, the greater the number of bonded surface and fewer unbounded surfaces, greater will the retention power be
C-factor
Filler Distribution
different sizes in a filler allow for greater total amount in a given volume
- large = strength
- smaller = higher polish/finishability
Recommended Use: Packable
class I, II, VI
Recommended Use: Flowable
small class III or V, pediatric, block-outs, liner, small repairs
Recommended Use: Microfilled
small class I, enamel replacement in class III,IV,V, veneers, diastema closure
Recommended Use: Conventional/Mirco/Hybrids
general purpose Class I-VI
Advantages Composite
esthetic time saving operator control/creativity minimally invasive biologic compatibility won't wear opposing dentition handling properties reparability long lasting - high strength
Critical Elements to Success
isolation
tissue management
proper bonding technique
Proper Placement Technique
incremental layering no more than 2mm thick layers
Purpose in Finishing/Polishing
high luster
plaque resistance
stain resistance
Desirable Properties: Handling
tackiness/stickiness, stiffness, spreadability, non-slumpy, ability to brush (flowables)
Desirable Properties: Multiple Applications
anterior, posterior, esthetics
