Lecture 7 Flashcards
Define erosion:
loss of cervical dental hard tissues by CHEMICAL action of acids, not bacterial
Define attrition:
loss of cervical tooth substance by tooth-to-tooth contact
Define abrasion:
loss of cervical tooth substance from factors other than tooth contact (tooth paste, toothbrush), mechanical frictional forces
Define abfraction:
loss of tooth substance from occlusal stress in the cervical region
3 main categories of non-carious cervical lesions:
erosion, abfraction, and abrasion
T or F? Pts are at increased risk for non-carious cervical lesions with increased age.
T
What often plays a large role in non-carious cervical lesions?
xerostemia
Clinical manifestation of abrasions:
V-shaped notch (brush), sharp angles, may exhibit sensitivity to hot and cold
Causes of abrasion:
tooth brushing, paste, tongue, dental floss, toothpicks, removable appliances, food
T or F? Toothpastes are abrasive in nature.
T
Causes of abfration:
teeth flex under occlusal load, transmitted ot cervical region causing rods to break where the tooth is thinnest. V shaped notches, associated with the loss of Class V restorations and wear facets (forces applied to cervical region due to occlusal forces)
What type of forces are responsible for abfraction?
flexural
What can help to determine the etiology of a NCCL?
the morphological presentation, wedge vs. saucer shaped
T or F? Etiology can be determined based on lesion shape of NCCLs.
F.
What makes it difficult to determine the etiology of an NCCL?
they are multifactorial, not just one etiology
How does abfraction begin?
occlusal forces causing tooth flexure in the cervical region
What should you check if you suspect that the NCCLs are associated with wear facets?
check occlusion for interference
At what part of the lesion do occlusal forces concentrate?
the deepest part
T or F? The deeper the lesion, the worse the stress, the faster the lesion will progress.
T
When not to tx NCCLs:
minimal lesion with no sensitivity, eliminate the etiological factor only
When to tx NCCL operatively:
sensitivity to thermal changes, and/or mechanical stimulation, esthetic concerns, nuisance-food collects, threat to the strength/integrity of the tooth due to depth
T or F? The deeper a lesion, the faster it will progress.
T
When to use a glass ionomer or RBGI to tx NCCL:
food trap, or sensitivity or threat to tooth structure
Tx for NCCL besides surgical:
preventive interceptive, de-sensitizing agents (fluoride, varnishes), bonded restorations (composites, RGMI’s), occlusal adjustments, occlusal guards (7:42)
T or F placement of a bonded resto will halt progression of a NCCL.
F. slow only, changes the distribution of the stress.
How is the stress altered with the placement of RBGI to tx a NCCL?
distribution of the stress, acts as a cushion
Class V indications:
caries, non-carious cervical lesions, replacement of existing restorations
External Outline:
Occluso-gingival width: 2mm wide measured at the center, Gingival margin: 1mm from gingiva, Mesio-distal width: centered messy-distally and extended to the MF and DF line angle
Appearance of non-carious cervical lesion
shinier, sharper in appearance
What type of restoration is todays Class V restoration?
Box-shaped type preparation
Goal of shaping the booth prep
90’ to the cavosurface margin
At what angle should all wall propose meet the external unprepared tooth structure?
90’
Why do we want a 90’ angle at the cavosurface margin?
bc of the way the enamel rods are oriented, we don’t ant unsupported enamel
What does it mean if you can see the cavosurface wall in its entirety?
it diverges toward the tooth surface
Where does the bevel begin?
the dej
why do we start the bevel at the dej?
to bond better (increase s.a. for bonding)
What should the length of the bevel be in any setting?
it varies
What is the etch that we use?
35% phosphoric acid
What bur should be used for contouring lingual surfaces of anterior teeth?
football
T or F? The tooth should be dry for bulk contouring and wet for fine contouring when finishing.
F. wet for bulk, dry for fine
Why does the Resin-enamel interface need to be undetectable?
surface staining, plaque accumulation, wear characteristics
Problem encountered when dry finishing:
disk gets clogged with abrasive particles, less efficient
What color disk should we start w in this project?
orange
Which disks are for polishing?
the 2 yellow
Do the polishing disks work better when stiffer or more flexible?
flexible
What are the finishing and polishing cups impregnated with?
abrasive materials
Advantage of rubber points and cups over disks:
access o grooves, O anatomy, and concave lingual surfaces of the ant teeth
Should the blue diacomp polisher be used with or without water?
with (medium)
Should the grey diacomp polisher be used with or without water?
slow w o (fine)
How many shapes and grit sizes of astropol (ivoclar vivadent) polishers are there?
4: small and large flames, cup, disk, 3 grit sizes
T or F? The astropol polishing cups should never be used with water.
F. Use w and rinse bw grits
Do we need polishing paste with the astropol polishing system?
no
What are engrained within the fibers of the astrobrush polishers?
silicon carbide (high gloss polishing)
What are the astropol cusp made of?
silicon rubber and aluminum oxide
T or F? The astropol cusp wear quickly and need to be replaced as soon as the outer layer of silicon carbide is worn down.
F. as bristles are worn, fresh abrasive medium is exposed on the surface
What are finishing strips made of?
metal or plastic
What are metal finishing strips used for?
gross reductions, usually amalgam
What are plastic finishing strips used for?
RBC restos
T or F? Rinse bw grits of the inter proximal strips.
T
At what angle should you used the #12 scalpel blade?
45’
12 scalpel blade is good for:
interproximal gingival excess remoal
What does the selection of the appropriate finishing and polishing system depend on?
contouring vs. polishing/ flat vs. curved surface
Contouring tools:
7901 burr, 7904 burr, ine grit diamond burr in slow speed, astropol (gray and green), and SofLex (red and orange)
Polishing tools:
astropol (pink), Spflex, (dark and light yellow) and astrobrush
What is the SofLex Kit (including madrel) good for?
Flat surfaces (finishing, contouring, and polishing)
What is the Astropol (points and cups) good for?
both flat and round surfaces (i.e. lingual of ant teeth, occlusal surfaces) (finishing, contouring, and polishing)
What is the Astrobrush good for?
Both flat and round surfaces (high gloss polish)
You might need #12 scalpel when filling these classes of resto:
Class II and Class III
What may result if we leave remaining composite past the bevel before we polymerize?
to remove we may take healthy tooth structure as well
Which color disc should we begin with for the finish?
orange
How to use the disc properly for finishing?
proper angle necessary
finishing includes:
contouring, shaping, modifying, polishing
Appearance of the tooth structure after using a disc:
dull
Why do we airdrop after the application of the bonding agent?
bc adhesives always work best in thin layers
