FINISHING AND POLISHING

The surface of the casting that is retrieved from investment is too rough for use in the mouth.Five

preparatory procedures need to be performed on any type of

cemented restoration after it has been fabricated

PROCEDURES

Preliminary finishingTry-in & adjustmentPre-cementation polishingCementation polishingPost-cementation finishing

• The internal and external aspects of restoration are handled differently.

• External surface smooth &perfect uninterrupted transition from restoration to tooth

• Rough surface plaque accumulation-injurious to health of periodontal tissue

• Try in satin finish after chairside adjustment high luster

• Finishing&polishing- accomplished with fixed routine-coarse and fine

ABRASIVES AND POLISHING MATERIALS

• ABRASIVES:exceptionally hard material that develop sharp cutting edges when they are chipped.

• POLISHING MATERIALS:abrasives of softer material that are reduced to extremely fine particle size.

COMMONLY USED ABRASIVES AND POLISHING MATERIALSDIAMONDSILICON CARBIDEEMERYALUMINIUM OXIDEGARNETSANDCUTTLETRIPOLIROUGETIN OXIDE

COMMONLY USED FORMS

SEPARATING DISCSMOORE’S DISCHEATLESS STONESBUSCH SILENT STONESGREEN STONESPINK STONESWHITE STONESRUBBER WHEEL AND POINTS

ZONES OF FINISHING AND POLISHING

• ZONE 1:INTERNAL MARGIN

• ZONE 2:INTERNAL SURFACE

• ZONE 3:SPRUE

• ZONE 4:PROXIMAL CONTACT

• ZONE 5:OCCLUSAL SURFACE

• ZONE 6:AXIAL WALL

• ZONE 7:EXTERNAL MARGIN

PRELIMINARY FINISHING OF GOLD

RESTORATION

PROCEDURES…

Inspect under surface of cast under magnification for small nodules or bubbles Remove nodule with no:330 bur in high speed .Trace negative angles on inside of occlusal surface with tip of burIdeally the cast should touch the die only in the marginal region –there should be a slight gap every where else for future cementation.A uniform space of 25 – 35micrometer necessaryIf nodules present removed with round carbide bur

Use a separating disc to cut the sprue from the castingDiagonal cutting plier may be used.Hold hand piece with a firm pen grasp while cutting the sprue next to the castingAvoid tipping the disc- if a disc binds in the cut grooves – it may flip the casting out of our handAfter removing the sprue , use separating to trim the remaining portion of sprue attachment on the casting until the contour in that area is continuous with the contour of the restoration surrounding the sprue

Sprue immediately adjacent to the casting is removed with separating disc

Use coarse rubber disc-to smooth away the roughness left by the separating disc.Use finer Burlew/gold lustre blue disc in similar manner after coarse disc-now entire surface smooth with satin finishAxial surface finished to the margin-do not extend over the margin-seat the restoration on the castAdjust the interproximal area-until restoration seats completely with contacting adjacent teeth

Axial surfaces are smoothed with Burlew wheel

Adjust occlusion in articulator-centric&eccentric

Remove restoration from working cast and place it back to die

No:0-”bud” finish bur – to smooth grooves on occlusal surface

Smooth cusp tips and blend them into the grooves on the occlusal surface with a small rubber sulci disc

External surface should have a satin like finish produced by Burlew rubber polishing wheel

TRY-IN & ADJUSTMENT

If careful and gentle no need of anesthesiaPatient’s unimpaired tactile sense can be valuable during adjustment of occlusionSmall safety ring provided by cutting a thin slice from hollow sprue

Attach it to the wax pattern where it will not interfere with occlusion

Thread floss through the ring before trying casting in the mouth.

A safety ring may be fashioned by cutting a thin slice from hollow sprue

Ring is luted to wax pattern

A length of dental floss is looped through the ring on the casting

Floss is allowed to hang out the corner of the mouth

• Remove provisional restoration by grasping the buccal and lingual surface with tips of backhaus towel forceps and rocking it to the facial and lingual.

• Remove the left cement particles• Wipe of prepared surface with cotton

pellet ( dry )• Wash with luke warm water

Provisional restoration removed with backhaus forceps

A)Richwil crown remover soaked in hot waterB)patient closes on softened cube

C)patient opens quickly and forcefully to remove crown

Evaluation of restoration in following sequence:

Proximal contactMarginsOcclusionContourEsthetics

Adjustment of proximal surface contact

Proximal contact – neither too tight nor too light.Place the restoration on the tooth & seat it with firm

finger pressure.Do not mallet / apply occlusal pressure.Crown can be removed with Richwil crown remover soaked in hot tap water for 1minPatient closes on the softened cubePatient opens quickly and forcefully to remove crown

Test for proximal contact with waxed dental floss

Satin finish on gold restoration - advantageous- shiny burnished area where tight contact occurs

Marginal adaptationAfter proximal contact corrected seat restoration and examine margin closely-should not be ;OverextendedUnder extendedToo thickOpen- gap greater than 50µm

Various materials used to detect discrepancies

Chloroform & rouge / thinned typewriter correction fluid-painted in the internal surface

Thin layer of dry aerosol indicators – sprayed DISCLOSING WAX: Fill restoration ½ full of disclosing wax Heat in flame to flow the wax & adhere to inner surface Teeth wet with saliva( avoid sticking of wax) Wax solidified seat restoration hold for 10 sec

then remove

Areas of metal – tooth contact –appear as shiny spot devoid of wax

Relief impinging areas with no:30 bur-allow restoration to seat further

Remove disclosing material by swabbing with chloroform and sand blasting

Tooth cleaned with cavilax

GOLD MARGIN FINISHING

2 types of margins- sub gingival & supragingival Casting placed on prepared tooth and have the patient seat

it by closing on plastic bite wafer/wooden stick Burnishing and marginal adaptation with dull spratley

knife(30µm adaptation) Finishing with white stone (60µm adaptation) Final precementation smoothening with 3/8 inch cuttle

disc

All accessible margins are burnished intraorally with a smooth dull

instrument

Margins are finished with a white stone rotating from gold to tooth

OCCLUSAL ADJUSTMENTAsk the patient to close in customary position

Check if patient can hold the shim in between adjacent teeth with crown out – if not the crown too high

Ask the patient to bite in centric relation

Force until all teeth touch

Cntd…..

• If mandible shifts to side of restoration

• Buccal incline of maxillary lingual cusp / lingual incline of mandibular buccal cusp adjusted

• If mandible shifts away from restoration

• BULLS

If patient can hold shim stock on adjacent teeth with the crown out,but not with it , the crown is

too high

Premature contact on buccal incline of maxillary lingual cusp produces buccal shift to mandible

Premature contact on lingual slope of maxillary buccal

cusp produces lingual shift of mandible

Premature contact on lingual incline of maxillary

lingual cusp produces lingual shift of the mandible

NON WORKING MOVEMENTS

• Non working interference

NON WORKING MOVEMENTS

• Working interference

CONTOUR

• Improper contour-impaired gingival health

• Excessive convexity near gingival margin

•

• Plaque accumulation

ESTHETICS

• Restoration viewed from conversational distance- see if contours harmonize with rest of patient’s dentition

• Let patient look in a mirror

PRE CEMENTATION POLISHING

Polished to high shine

polish axial surface with Tripoli on soft bristle brush

occlusal anatomy restored (171 L carbide bur )

• Shiny finish • Matt finish (sandblasting)

• Enable observation of facets/burnishing produced by occlusal contact after casting in mouth

Masking tape is wrapped around the casting

Only the occlusal surface left uncovered

Casting placed in sand blaster

Air brush used to apply a matte finish to occlusal surface of the casting

POST CEMENTATION FINISHING

Occlusion checked Finishing with fine rubber point White polishing stone with lubrication

(petrolatum) To inaccessible areas Fine cuttle disc Pumice and rubber cup FINAL POLISHING by – intraoral

amalgloss

Thank you