Lec 1/12 Partial FDP MCC & ACC I Flashcards
Indications for leucite based fixed prosthesis:
anterior crowns, veneers, inlays and onlays
Indications for lithium silicate based fixed prosthesis:
ant/ POST crowns, veneers, inlays, onlays, 3-UNIT ANT FDP
consequences of tooth loss:
M-D drift of adjacent teeth, supraeruption of opposing teeth, premature contacts created during protrusive movements, alterations in occlusion, bone loss, possible loss of VD
Options for replacing a missing tooth:
implant, PFD, RPD, Resin bonded FDP, no tx
Comparison of survival rates of implants and FPD after 10y
about same
Most common complication for conventional tooth-supported FDPs:
biological: caries, loss of pulp vitality
Most common complication for implant-supported reconstructions:
technical complications
caries under adjacent tooth for FP is considered a failure of:
the treatment
For teeth w/ endo treatment, how does extraction and replacement w PFD compare w replacement w an implant supported prosthesis?
FDP lower longterm (10y same) survival than implant
Aspects to eval when determining tx options for missing tooth:
edentulous area, perio health, caries on adjacent teeth, is occlusion stable?, root length and shape, bone support, divergent/ non-divergent roots (conical roots are the worst), quality and extension of caries/ restoration, H/W of edentulous area at MIP
What always come before treatment?
disease control
What needs to be eval if adj tooth to edentulous area has had an RCT and you are thinking about placing a FDP?
amount of ferrel
Ante’s Law:
combined pericemental area of all abutment teeth supporting a FDP should be equal to or greater in pericemental area than tooth or teeth to be replaced
Law of Beams:
deflection of force is proportional to the cube of its span
What to do after diagnostic work-up and tx plan and before appt to start prepping tooth:
make shell for interim FDP and custom tray
What to do after prepping adjacent teeth?
definitive impression, interocclusal record MCC/ACC shade and Interim restoration
What to do after definitive impression interocclusal record MCC/ACC shade and Interim restoration
pindex, trim, mount the working cast, wax up, sprue and invest
Metal alloy types that can be used for indirect:
III and IV
Metal alloy type that can be used for short-span FPD:
III
Type I alloy can be used for:
some, not all, inlays
Type II alloy can be used for:
inlays and onlays
Type IV alloys can be used for:
long span FPD, RPD
How are metal alloys categorized?
yield strength and elongation
Noble alloy:
25% noble, no stipulation for gold
Base metal alloy:
Less than 25% noble metal
Ti and TI alloy:
85%+ Ti
High noble:
at least 60% noble and at least 40% gold
3 types of porcelain:
opaque, body, incisal
Type of porcelain responsible fo rmetal-ceramic bond
opaque
Porcelain type that provides some translucency and contains metallic oxides that aide in shade matching:
body porceliain
Translucent porcelain type:
incisal porcelain
Factors affecting the bond:
oxide layer thickness, bonding agent, airborne particle abrasion, linear CTE
Higher flexure strength, metallic alloy or feldspatic porcelain?
metalic alloy
TF? Greater deflection leads to greater likelihood of breakage.
T
Is porcelain stronger in compressive or tensile strength?
compressive
CTE
Change in length per unit length of a material for every 1’ temp change
Ceramic CTE:
13 -14 X 10^-6/C’
metal alloy CTE:
13.5-14.5 X 10^-6/C’
CCC reductions:
margin: 0.5mm, Non-functional cusp: 1mm, Functional 1.5mm
MCC reductions:
Lingual: 1mm (metal only), Buccal: 1.5mm (1.2mm porcelain, 0.3mm metal), Incisal 2mm (1.5mm porcelain, 0.5? metal) Non-functional cusp: 1.5mm, Functional 2mm
ACC reductions for anterior tooth:
Incisal: 1.5mm, Lingual / Facial: 1mm shoulder margin
ACC reductions for posterior tooth
Margin: 1.5mm, occlusal: 1.5-2mm, 1mm shoulder margin
3 PFM margin types:
knife edge, metal collar, porcelain margin
4 PFM Occlusal Surfaces:
metal lingual (anterior), porcelain lingual (anterior), metal posterior, porcelain posterior (?don’t understand, check?)
PFM Ceramic Margin:
Gen only the labial area in esthetic zone, requires a smooth, 1.2mm finish line w round internal angle, slightly sub-gingival (equigingival), technique sensitive
Bur for PFM ceramic margin:
modified shoulder
Bur for metal collar PFM prep:
chamfer, 0.5 lingual reduction
Bur for knife edge PFM:
chamfer, right?
PFM metal ceramic margin:
mid-sulcus prep, acceptable result if fabricated properly, simplifies crown fabrication, many clinical problems
Clinical problems assoc w metal-ceramic margin PFM:
gingival over-contour, rough porcelain surface, non-esthetic after gingival recession NOT RECOMMENDED
When to use metal collar framework design for PFM
non-esthetic areas
Benefit of metal collar framework design for PFM
easier porcelain application