1. Amalgam - An alloy that is formed by reacting mercury with silver, copper, and tin, and which may also contain
palladium, zinc
a. Irregular, spherical, lathe cut
b. Silver-tin alloys are quite brittle and difficult to blend uniformly unless a small amount of copper
is substituted for silver.
c. zinc in an amalgam alloy is to act as a deoxidizer, which is an oxygen scavenger that minimizes
the formation of oxides of other elements in the amalgam alloys during melting.
d. Ag3Sn (γ phase), Cu3Sn (ε phase), Silver-Mercury (gamma I), Tin-Mercury (gamma II)
e. High copper amalgams- 11.8% by weight.
f. Creep- Creep rate has been found to correlate with marginal breakdown of conventional lowcopper amalgams; that is, the higher the amount of creep, the greater is the degree of marginal
deterioration. Creep causes the amalgam to flow over time such that unsupported amalgam
protrudes at the margin of the restoration. Because of low tensile strength and the onset of
corrosion, the protruded segment of amalgam fractures and leaves a ditch around the margin
g. If the amalgam is properly inserted, leakage decreases as the restoration ages in the mouth. This
may be caused by corrosion products that form in the interface between the tooth and the
filling,
2. Composite
a. Components
i. Resin Matrix – monomer, initiator, inhibitors, pigments
ii. Inorganic Filler- glass, quartz, silica
1. Macrofillers (10-50um), Microfiller (40-50nm), Hybrid (both macro and micro),
nano composite (nanomers- 0.02-0.07nm and nanoclusters 0.6-1.4nm)
2. Similar performance of nanocomposites and microhybrids
iii. Coupling Agent
b. Flowable Composites
i. Similar particle sizes to hybrids, lower viscosity, inferior mechanical properties
c. Incremental vs Bulk Fill
i. Incremental- shrinkage stress
ii. Bulk Fill- less porosity
1. Depth of cure increased by translucency, additional photo initiator
d. Beveling- does not improve clinical or esthetic success.
3. Bonding Agents
a. Generations
i. 4th- 3 step etch and rinse
ii. 5th – 2 step etch and rinse
iii. 6th – 2 step self etch, 1 step self etch (mix)
iv. 7th – on step self etch (no mix)
b. Etch and Rinse- good enamel etch, but sensitive to dentin wetness after rinse
i. 37% phosphoric etch, Primer (HEMA, GPDM, PAMM), Adhesive (Bis-GMA)
c. Self Etch- good dentin conditioning (etch and prime infiltrate same depth of dentin
simultaneously), no rinse so no dentin wetness sensitivity, but may require refrigeration
and lower bonding strength to enamel.
i. Acidic Monomers – MDP, Di-HEMA-Phosphare
ii. Crosslinking Monomers (Bis-GMA, UDMA)
iii. Solvent (water)
d. Universal - may be used as self-etch (SE) adhesives, etch-and-rinse (ER) adhesives, or as
SE adhesives on dentin and ER adhesives on enamel (a technique commonly referred to
as “selective enamel etching”)
4. Caries
a. Diagnosis- visual inspection deemed sufficient alone for caries detection
b. ADA Caries Classification
i. Sound
ii. Initial- mild decalcification, only noticeable after drying, E1-D1
iii. Moderate- Visible enamel breakdown or signs of dentin demineralization, D2
iv. Severe- cavitation with dentin exposure
5. CAMBRA- identify cause and risk factors of caries and correct cause and risk factors, not drill and
fill
a. Fluoride- evidence is in favor of fluoride application every 3-6 month for children 0-18
years old. Expert opinion suggests use in adults
b. Pit and Fissure Sealants – 76% reduction in caries rate, minimize progression of occlusal
caries, work better than fluoride for pit and fissure caires
c. CHX- evidence shows chx/thymol varnish every 3 months can reduce incidence of root
caries. Use of CHX varnish alone or in combination with fluoride for caries prevention is
NOT recommended.
d. Xylitol- evidence is of low quality to suggest xylitol can prevent caries
e. ACP- evidence suggests that ACP can be used to augment flouoride in caries prevention.
f. Minimally Invasive Tx
i. Non-invasive (remineralization) tx better than control for avoiding invasive
treatment
ii. Micro-invasive (pit and fissure sealant) better than non-invasive for preventin
invasive
iii. Pit and fissure sealants effective at preventing invasive treatment but often
require retreatment more often than remineralization or PRRs
iv. Teeth with caries and sealants
1. Sealed teeth show no caries progression
2. Unsealed teeth show caries progression
g. Partial Caries Removal- success is equivalent to complete caries removal, success
depends on adequate seal, can reduce pulpal exposure by 98%
h. Pulp capping Agents- Dycal, MTA, Biodentine, Theracal