Karteikarten
RESTORING CAVITIES WITH DENTAL AMALGAM
Karten in diesem Stapel (12)
- 1AMALGAM:an alloy with mercury and another metalHISTORY 1833: Crawcour brothers introduced it in US - powdered silver coins with mercury - expanded on setting
- 21895 GV BLACK: develops new formula of modern amalgam - 67% silver, 27%tin, 5% copper, 1%zincOvercame expansion problems!
- 31960's - conventional low copper lathe cut alloys - smaller particles.1960's - 1st generation high copper alloys - admixture of spherical cut Ag-Cu particles with conventional lathe cut - This cut out gamma 2 phase
- 41970’s first single composition spherical ternary system (silver/tin/copper) 1980’s alloys similar to those in 70’s 1990’s mercury-free alloys (gallium) Increased corrosion & excessive post setting expansionAMALGAM TODAY: low copper alloys, admixed high copper alloys, single composition high copper alloys. TODAY:copper enriched used - encapsulated to reduce risk of mercury contamination
- 5WHY AMALGAM: inexpensive, easy to use, durable (can last for 10yrs +), familiarity with material, less likely to have hypersensitivity than with compOUTLINE FORM: gain access to caries, leaving sliver of enamel approximally. Remove with ging marginal trimmer or excavator. Access is gained to caries
- 6REMOVE CARIES: from EDJ first then base of cavity. Ensure any unsupported enamel is removed, ensure resistance/and retention features are in placeRESTORE: place lining if necessary, matrix band and pack amalgam. Trim and carve removing surface mercury layer
- 7THERAPIST CONTROLLED VARIABLES: Trituration(mixing time) refer to manufacturer. Overtrituration-hot sticky mix, sets fast. Undertrituartion- grainy mix, longer to setCONDENSATION: Force used to pack and place amalgam. LATHE CUT- small condenser with high force. SPHERICAL ALLOY-large condensor, less sens to force, vibration motion. ADMIXTURE - mix of both above
- 8CONDENSATION RULES! condenser must fit.. check before mixing! Place amalgam in small increments and pack Overpack and remove mercury rich layerCARVING RULES!
carve back to cavity outline
Remove mercury layer
check occlusion, aim for smooth enamel margin junctions - 9BURNISHING: PRE CARVE - removes mercury and improves margins POST CARVE - improves smoothness COMBINED - less leakagePOLISHING AMALGAM:
24 hrs after setting - increases smoothness, lees corrosion and less plaque retentive
Clinically effective? 'Collins and Djent' no improvement of margin integrity - 10BONDED AMALGAM RESTORATION used when there is not enough tooth substance ie missing cusp and for complete marginal seal to prevent ingress of bacteria and protects pulpADVANTAGES:
No need to use dentine pins
no retentive/resistance features required
reduced marginal leakage - 11DISADVANTAGE: Time consuming costly Lack of evidence on long term prognosisTECHNIQUE:
Vitrebond liner placed
Acid etch, prime and bond
Rely X ARC material placed (DO NOT LIGHT CURE) amalgam packed on top - 12AMALGAM TOXICITY: Toxicity - mercury poisoning Allergy - to amalgam may cause contact dermatitis or Lichen Planus PREGNANT PT'S - theoretical rick to foetus as mercury can pass through placentaMERCURY POISONING SYMPTOMS:
headache, salivation or xerostomia, GI upset, Dyspepsia, severe gingivitis, tremors, fatigue, odema of face and neck, character changes
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- Beschreibung
- Restorative dentistry Karteikarten am RESTORING CAVITIES WITH DENTAL AMALGAM, erstellt von aahughes am 27/11/2013.
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- aahughes
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