mini assessment 4 Flashcards
Goals of Isolation of the Operating Field
- moisture control
- retraction
- harm prevention
Moisture Control
- saliva, blood, crevicular fluid, humidity
- necessary for proper restorative material applic
- bonding procedures need moissture controls for optimum results
Retraction
- access and visibility
- lips, cheek, tongue, gingival tissue
harm prevention
- prevents aspiration/swallowing of objects
- protexts tissues from instruments
- protects patients from irriating materials/ bad taste
- protexts operator from saliva + aerosol (infection control)
1-rubber
2-hole punch
1-1864, dr. sanford barnum
2-1882- SS White
Rubber Damn isolation
- protect patient
- patient comfort
- better visualization
- improve qualit of care
- inc. productivity
- improve retention of bonded restorations
- infection control
- for licensing exam
disadv of rubber damn
- may not be places where there is insuffiecient eruption of teeth so no clamp stability
- time consuming
- patient objection
Materials used for Rubber Dam
- non latex
- medium
- darker colors are preferable
1-young frame
2-plastic frame
3-clamp forceps
1-metal—U shaped w/ open end towards nose
2-endodontics, doesnt interfere w/ radiographs
3-placement/removal of clamb from abutment of tooth—-open jaws of the clamp and carries clamp to tooth
1-wingless retainer
2-winged retainer
3-Retainers
1-positioned on tooth w/o rubber dam, damn goes over retainer…easier to see placement of retainer
2-damn is placed on wings of retainer and both applied at once
- one step application
- wings give additional retraction from rubber damn
3- 4 pts of retainers contact tooth at line angles
engage tooth cervical to height of contour
not extend past mesial & distal angles of tooth bc it would inferfere w/ matrix/wedge placement
may get gingival trauma
1- retainers with points directed gingivally
2-N27
3-13A
4-12A
5-14A
6- anterior retainer
1-placement on partially erupted teeth
2-small molars
3-lower left & upper right molars
4-lower right & upper left molars
5-partially erupted molars
6-retainer is placed after rubber damn, gives retraction of gingival tissue & protects gingival tissue
other methods to retain rubber damn
- wedgets
- rubber damn material
- ligation w/o floss
-usually w/ anterior of mouth
1-size 1
2-size 2
3-size 3
4-size 4
5-size 5
1-mand incisors
2-max incisors
3-canines & bicuspids
4-molars
5-molars
1-extension for the posterior teeth
2-extension for the incisors
3-extension for canine
4- minimum extension for restorative procedures
1- 1-2 teeth posterior to the treatment tooth to the contralateral canine
2-from 1st premolar to 1st premolar…may/may not need clamps
3-1st molar to contralateral canine
4-3 teeth: treatment tooth, 1 tooth anterior, 1 tooth posterior
Problems w/ holes
1-holes punched too close together
stretches the dam too much
causes gaps
2-holes punched too far apart
too much dam material between teeth
causes bunching
—double punch hole w/ the retainer
Placement of Retainer
- forceps open jaw of retainer and carry retainer to tooth
- bow is towards distal
- seal retainer from lingual then over buccal contour
Isolation of Teeth
- pull dam over bow
- after posterior tooth isolate, isolate anterior
- secure anterior w/ wedget or clamp or floss
- leave teeth in betwene until frame is in place
- isolate the rest of the teeth
Winged Clamp Technique
- dam is on retainer
- dam & retainer go at the same time
- winged retainer & damn are placed on posterior abutment at same time
Rubber dam removal
- remove debris
- cut septa
- remove wedgets
- remove clamps/ dam at same time
Other methods of Isolation
- cotton rolls
- dry angles
- super clamp—retracts & protects tongue and lip
- optra damn—3D, frame dam all in one
- optragate—retraction of lips and cheeks, doesnt isolate each tooth
- isoprep retractor—bleaching
- isolite system—retracts tissue, suction, & light
Enamel
- inorganic
- prisms are made of hydroxyapatite crystals
- –parallel to one another
- –from DEJ to outer surface in radial pattern
- in key hole like pattern
Etchants
- phosphoric acid
- gel so it stays in place
- removed via rinsing
Etching Enamel
- 30-40% phosphoric
- 15-30 s of demin of surface
- inc surface area for bonding
- inc surface roughness
- dec surface tensions
—frosty white appearance
-addition of bodnign resin makes resin tags in etched enamel= micromechanical retention
problems w/ etching
- over etching
- etching= decalcification to a big depth—no etch pattern
- dec ability to form resin tags
- lower bond strength
- clinically overetched enamel cant be distinguished
- outer 5 um of enamel= amorphous, if unprepared = more etching time
- if has fluorosis needs more etching time
-bond strength to enamel is reduced when etched enamel= contaminated (blood, saliva, oil) and then etch surface again for 10 s
1- enamel
2-dentin
1-more minerals than water, very little organic
2-50% minerals, and then 25% 25% for organic & water
Smear Layer
-cavity prep = smear layer
- debris from grinding & organic matter
- smear layer differs depending on instruments
- makes smear plugs in tubules
- loosely adheres to dentin
1-dentin
2-bonding to dentin
1-dentin is always wet
smear layer is present
when smear is removed, fluid seeps out of tubules
communicates w/ pulp
2-30-40% phosphoric, 15 s, removes smear, demineralizes surface dentin
1-bonding to enamel
2-enamel/dentin bonding systems
1-bonding system
- etchant (30-40% phos)
- adhesive—-hydrophobic resin, works bc very little H20
2-etchant (37% phos)
- primer—hydrophillic in solvent (acetone, ethanol, H20)
- adhesive—hydrophobic resin
1-enamel bonding
2-dentin bonding
3- what happens when dentin is etched
1-inorganic
can be dried
hydrophobic resin can be applied to dried enamel and cured
2-organic
dentin is wet and stays wet
hydrophyllic primer is needed
3-smear layer is removed
dentin is demineralized
collagen layer remains
Dentin cant be dried…
- must be moist to prevent collapse of remaining collagen
- if dried, bond strength to dentin decreases
- if dried then must be rewet to rehydrate
- must be primed, priming removes residual H20 to allow for infiltration of hydrophobic adhesive resin
Adhesive
- applied to dentin
- light cured
- making a hybrid layer= collagen surrounded by resin