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1. CONTENTS
 Introduction
 Objectives of finishing and polishing
 Finishing, cutting, grinding and polishing procedures
 Finishing and polishing instruments
• Hardness of abrasives
• Abrasive instrument design
A) Abrasive grits
• Type of abrasives
B) Bonded abrasives
• Finishing burs
• Diamond instruments
C) Coated abrasive disks and strips
D) Cloth and felt
 Abrasive and erosive wear,
 Other finishing procedures
• Microabrasion and macroabrasion
• Burnishing,
 Finishing of different restorative materials
• Amalgam
• Composite
• Glass ionomer cement
• Direct gold restorations
• Cast gold restorations
• Porcelain
 Health hazards of finishing and polishing

2.  References
 Conclusion.
Introduction :
The main objective of an operative dentist is to restore the individual
tooth to its form and functions along with imparting pleasing esthetics and
maintaining periodontal tissue in good esteem. It has been established that
rough or uneven surfaces initiate microbial flora to flourish and also light
reflected by these surfaces may not be even and uniform. Therefore a
restored tooth should be evenly smooth and reflect light uniformly. The
process of making the surface smooth is known as finishing and polishing.
Finishing is defined as the transformation of an object from a rough to
a refined form. The procedure involves removal of surface irregularities and
shaping the restoration according to functional occlusan polishing is defined
as the production of a shiny mirror like surface, which reflects light similar
to enamel.
Objective of Finishing and Polishing :
The objective of finishing and polishing of any restoration are
obtaining adequate adaptation and continuity of the restoration. Margins,
with the tooth, optimum restoration contour, proper occlusal contacts and a
surface free of any scratches or irregularities to make it biologically
acceptable. All these objectives lay the foundation for optimum oral health
function and esthetics.
i) Oral health: a well contoured and polished restoration will have
reduction in total surface area and reduced roughness of the restoration
surface which promotes the oral health by resting the accumulation of
food debris and pathologic bacteria. Smoother surfaces are easier to
maintain in a hygiene state when preventive oral home care is practiced.

3. With some restorations tarnish and corrosion activity can be
significantly reduced if the entire restoration is highly polished, which is
very important for the biocompatibilite property of a material.
ii) Oral function: Oral function is enhanced with a well polished
restoration because food glides more freely over occlusal and embrasure
surfaces during mastication.
Smooth restoration contacts, minimize wear rates on opposing and
adjacent teeth, which is particularly true for restorative materials such as
ceramics that contain phases that are harder than enamel and dentin.
Friction is the resistance to motion of one material body over another.
If an attempt is made to more one body over the other a restraining force to
resist motion is produced. The co-efficient of friction is reduced if the
surfaces are smooth and in single plane. Reduction in friction results in
reduction in wear which interns helps in longevity of restoration.
Rough material surfaces lead to the development of high-contact
stresses that can causes the loss of functional and stabilizing contacts
between teeth.
iii) Esthetics : Aesthetic demands may require the dentist to handle
highly visible surfaces of restorations differently than those that are not
accessible, Because.
When white light shines on a solid, some of the light is directly
reflected from the surfaces and remains white. This light is mixed with the
light reflected from the body of the material and dilutes the color.
As a result an extremely rough surface appears lighter than the
smooth surface of the same material. This problem is associated with
unpolished or worn glass ionomers and composite restorations.
The opacity, translucency and transparency of a dental material is
affected by the surface characteristic of the material.

4. Opacity is a property of materials that prevents the passage of light.
An opaque material may absorb some of the light and reflect the remainder.
For example the core material of porcelain is opaque it reflects yellow light
so it appears yellow.
Translucency is a property of substrate that prevents the passage of
light but disperses the light, so objects can’t be seen through the material.
Some translucent materials used in dentistry are ceramics, resins,
composites etc.
Transparent material allow the passage of light in such a manner that
little distortion takes place and objects may be clearly seen through them.
Finishing, Cutting, Grinding and Polishing Procedures :
Finishing can also be described as a process where by substrate
particles are removed by the action of cutting and or grinding. The surface
of the substrate in made to come in to frictional contact with a
comparatively harder material. This contact generates enough tensile and
shear stresses to over come the forces of atomic bonds and there by release
particles from the substrate.
In a cutting operation the substrate particles are, removed by the use
of a bladed instrument or any instrument in a blade like fashion. A grinding
operation on the other hand removes small particles of the substrate through
the action of bonded or coated abrasive instruments. These instruments
contain randomly arranged abrasive particles. Both cutting and grinding
procedures produce unidirectional scratches.
Polishing is the most refined process and acts on an extremely thin
region of the substrate surface. It procedures very fine scratches that can be
visible only under very high magnification.
Basically polishing is the process in which the polishing material
dos’t cut or grind, but fills fine scratches and procedures a perfectly smooth
surface. During the polishing of metals a highly stressed microcrystalline

5. layer is formed on the surface called the “Beilby layer”. It is believed that
because of the rapid movement of the polishing agent, top layer of the
material gets heated up causing it to flow and fill the scratches.
During these procedures :
i) Surface blemished and imperfections are removed
ii) The material is shaped to an ideal form and
iii) The outermost surface of the material is developed to a desired
state.
Finishing and Polishing Instruments :
Hardness of abrasives: One of the most important characteristics of
abrasive particles on dental instruments is, it must be great enough to
remove particles of substrate material without becoming dull or fracturing
too rapidly. The hardness of a material can be measured by using MOHS,
KNOOP or VICKERS hardness tests.
Abrasive Instrument Design :
A) Abrasive Grits :
Abrasive grits are derived from materials that have been crushed and
passed through a series of mesh screens to obtain different particle size
ranges. Dental abrasive grits are classified as coarse, medium fine and super
fine, according to particle size. Along with this the shape of particle also
plays a major role in its selection.
Many types of abrasive materials are available they can be classified
mainly in to two types.
i) Natural abrasives : Arkansas stone, Chalk, Sand
Corundum stone, Diamond, Tripoli
Emery stone, garnet, zirconium silicate
Pumice stone, quartz
ii) Manufactured or synthesized materials.

6. They are generally preferred because of their more predictable
physical properties.
Silicon Carbide, Aluminium Oxide
Synthetic Diamond, Rough, Tin Oxide
B) Bonded abrasives :
Bonded abrasives consists of abrasive particles which are
incorporated through a binder to form grinding tools such as points, wheels,
separating disks and a wide variety of other abrasive shaper. Particles are
bonded by four general methods.
a) Sintering
b) Vitreous bonding (Glass or ceramic)
c) Resinoid bonding
d) Rubber bonding
Sintered abrasives are strongest type because the abrasive particles
are fused together
Vitreous bonded abrasive are mixed with a glassy or ceramic matrix
material, then cold presses to the instrument shape and finally fired to fuse
the binder.
Resin bonded abrasives are cold pressed or hot pressed and then are
heated to cure the resin. Rubber bonded abrasives are made similarly.
The type of bonding method employed for the abrasive greatly affects
the grinding behaviour of the tool on the substrate. An ideal binder holds the
abrasive particle is the tool sufficiently long enough to cut, grind or polish
the substrate, yet release the particles either before its cutting efficiency is
lost or before heat built-up causes thermal damage to the substrate.
A bonded abrasive instrument should always be trued and dressed
before its use.

7. Truing is a procedure through which the abrasive instrument is run
against the harder abrasive block until the abrasive instrument rotates in the
hand piece without eccentrically or runout when placed on a substrate.
The dressing procedure like truing is used to shape the instrument but
accomplishes two different purposes. First the dressing procedure reduces
the instrument to its correct working size and shape. Second it is used to
remove clogged debris from the abrasive instrument to restore grinding
efficiency during the finishing operation.
The clogging of abrasive instrument with debris is called abrasive
blinding, which results in reduction in abrasive efficiency and more heat
generation. So frequent dressing of the abrasive instrument during the
finishing operation on a truing instrument, maintains the efficiency of the
abrasive.
Diamond instruments are pre-shaped and trued so are not treated like
the bonded abrasives. Diamond clearing stones are used on the super coarse
through fine grades to remove debris build up and to maintain grinding
efficiency.
C) Coated abrasive disks and strips :
Coated abrasives are fabricated by securing abrasive particles to a
flexible backing material (heavy weight paper or Mylar) with a suitable
abrasive material. These abrasives typically are supplied as disks and
finishing strips.
D) Cloth :
Cloth carried on a metal wheel may be used for final polishing with
or without a polishing medium.
E) Rotary rubber instruments :
Rubber ended rotary tools are commonly used for polishing
procedures. They can be obtained in various shapes of cups, wheels, cones
etc. and are commonly used with other abrasives or polishing pastes.

8. ABRASIVE AND EROSIVE WEAR :
Wear is a material removal process that can occur whenever surfaces
slide against each other. In dentistry the process of finishing a restoration
involves abrasive wear through the use of hard particles. In case of a
diamond bur abrading a tooth surface, the diamond particles bonded to the
bur represent the abrasive and the tooth is the substrate.
It is important to observe the rotational direction of a rotary abrasive
instruments to control its action on the substrate surface when a hand piece
and bur are translated in a direction opposite to the rotational direction of
the bur at the surface being abraded, a smoother grinding action is achieved.
However when the hand piece and bur are translated in the same direction as
the rotational direction of the bur at the surface, the bur tends to “run away”
from the substrate, these by producing a more in controlled grinding action
and rougher surface.
Abrasive wear is further divided in to the processes of two body and
three body wear.
a) Two body wear: This occurs when abrasive particles are free to the
surface of the abrasive instrument and no other abrasive particles are
used.
Ex: A diamond bur abrading a tooth.
b) Three body wear: This occur when abrasive particles are bonded to
translate and rotate between two surfaces.
Dental prophylaxis which involves the use of a rotating rubber cup
and an abrasive paste on a tooth or a material surface is an example of a
three body wear.
Erosive wear :
Erosive wear is caused by hard particles impacting a substrate
surface, carried either by a steam of air or a steam of liquid. It is mainly

9. used in laboratories for grit blasting units that employ hard-particle erosion
to remove surface material.
A distinction must be made between this type of erosion and chemical
erosion, which involves chemicals such as acids and alkalies instead of hard
particles to remove substrate material, chemical erosion is commonly called
as acid etching.
Other Finishing Procedures :
i) Micro and macro abrasion
a) Micro abrasion: Earlier in this technique a paste made of 18%
hydrochloric acid, pumice and water was used. The paste was then
applied to the desired surface with a hand device like tongue blade or
a rotary driven rubber cup, which has a fluted edges, the rubber cup
should be rotated at a very slow speed to avoid removing any excess
tooth structure and prevent spatter.
Croll further modified the technique by reducing the concentration of
the acid to approximately 11% and increasing the abrasiveness by
using silicon carbide particles instead of pumice, is a water soluble
gel paste, this is more safer due to low acid content.
Recently EMS has introduced AIR-flow HANDY systems which uses
sodium bicarbonate as an abrasive agent. The powder is passed
through the narrow nozzle of specially designed hand piece with the
help of compressed air.
This technique is used to remove extrinsic stains on the tooth surface.
b) Macro abrasion: This is a also a technique for the treatment of
surface stains and defects but utilizes a 12-fluted carbide bur or a
micro diamond point revolving at high speed to remove the defect.
Adequate air/water spray should be used not only as a coolant, but
also to facilitate proper visibility of the defect.

10. ii) Burnishing :
Burnishing is defined as the process of rubbing a metal over the
restorative material to make it shiny or lusterous. Further it acids in
adaptation and compaction of material at margins.
The metal of the burnishing instrument should not combine easily
with the metal or alloy being burnished; otherwise some metal may be
transported either on to the restoration or restoration on to the instrument.
Stainless still or chromium plated instruments are commonly employed
either by hand or in the form of smooth rotating engine burnisher.
This technique is employed in,
• Finishing amalgam
• Finishing gold restoration
• Finishing cast gold restorations
FINISHING OF DIFFERENT RESTORATIVE MATERIALS :
1) Dental amalgam restoration :
Although few authors say that polishing of high copper amalgam is
less important as it is resistant to tarnish and corrosion it is often necessary
to
i) Complete carving
ii) Refine the anatomy contours and marginal integrity
iii) Enhance surface texture of the restoration.
Additional finishing and polishing procedures of amalgam restoration
is not initiated until first 24 hrs as the crystallization process is not
complete.
• Burnishing the restoration before and after carving
reduces the surface roughness by ten times.
• After 24 hrs, the surface of the restoration is usually
rough due to the heterogenous structure of amalgam on setting.

11. Finishing is then begun with the use of steel finishing burs or stones.
This includes trimming any overextended and excess margins, creating
adequate contour and correcting any occlusal disharmonies that may have
been overlooked during carving process. A high point in an amalgam
restoration appears as a shiny area, which is reduced with carborundum
stones or sharp finishing burs.
For the proximo-occlusal restorations, finishing begins with a careful
appraisal of the cervical margins, buccal and lingual proximal and occlusal
margins.
Despite the fact that matrix bands and wedges are used during
restorations, gingival overhangs of varying degree may be present. These
overhangs are reduced by using rhein trimmers, bard parker knives,
periodontal files or gold foil knives. Finishing of cervical areas is done by
inserting fine water resistant strips cervical to the contact area through the
interdental space and moving them to and fro.
Removal of superficial scratches and irregularities is accomplished
simultaneously. It should be remembered that abrasives always should be
applied through a descending grade, i.e. coarse, medium, fine and ultrafine
to achieve the best, finish. Suitable polishing agent like tinoxide, zinc oxide,
chalk, pumice, extra fine silex etc. carried with a soft rotating brush or
rubber cup.
For polishing in this contact areas and gingival embrasures, the
abrasive is introduced through polishing strips and dental tape.
During polishing, the restoration should be kept moist and only low
rotational speeds with light intermittent pressure should be used, to avoid
any over heating.
Excessive heat production (600
C) will permanently damage the pulp
tissue and the mercury present in the restoration reaches the surface which
leads to loss of material property of amalgam.

12. With the advent of high copper amalgams, it is now possible to finish
the restorations much earlier, i.e. 15-30 minutes after condensation.
Finishing and Polishing of Composite Restorations :
Composite reins have been widely used as an anterior restorative
material and are now being used in posterior teeth also. The surface
smoothness varies with the type of composite resin, owing to the nature of
the filler particles.
i) Conventional composites: These pose greatest difference in
hardness of organic and inorganic phases. The resin matrix is soft and
filler particles are hard if fine grit polishing methods are used, the foster
rein matrix abrades away easily leaving behind the harder filler particles,
which gives it a rough surface. If coarse abrasions are used on the other
hand, the organic and inorganic phases are removed equally but the
abrasives have behind rough marks.
ii) Hybrid composites can be polished to a semi-gloss but the surface
is somewhat hydrophobic which makes it quite unpleasant for the
patient.
iii) Microfilled composite materials can undoubtedly be polished to
the highest gloss and are considered to be esthetically best amongst all
composites. The surface of these restorations is highly smooth and the
chances of extrinsic staining are minimal. Finish obtained on micorfilled
composites is a glossy one where that obtained on conventional
composites is a satin finish.
A surface finish attained with the use of a plastic matrix bond is the
most desirable finish for resin restorations, but this is rarely obtainable
because of the need for contouring and removal of excess material, which is
often required clinically. Hence it is advisable to contour the unpolymerized
composite with hand instruments, so that the need for removal of large
amounts of set resin leading to surface damage are minimized.

13. a) Finishing of direct composite restorations :
Excess composite at the cavosurface margins is scraped away using a
scalpal or a sharp gold knife. The use of stainless steel instrument should be
avoided, as these tend to leave grey marks on the restoration. For gross
contouring the finishing of the concave and comparatively non-accessible
areas on the occlusal surface, the alpine stone, 12-30 fluted carbide burs and
diamond points are recommended. Rotary instruments should always be
used in slow speed and with a stream of water and little pressure. High
pressure tends to loosen and dislodge the filler particles. In the accessible
and convex areas of the occlusal surface agents such as aluminium oxide,
cuttle fish or silicon dioxide coated disks and strips are used in a descending
grade of their abrasiveness. Vaseline or petroleum jelly should be used by
used as lubricant with these disks and strips. These disks should be used in
to and fro motion. Strips are used to polish the proximal surface with short
strokes rather than rapid lengthy strokes in the embrasure.
In class-V restorations care must be taken to avoid gingival damage
in class-V restorations.
The final luster is obtained with polishing pastes that may contain
pumice, silica, alumina, tin oxide etc.
After the final polishing of the composite is completed a thin layer of
glaze may be applied to improve surface smoothness. Glaze is a film of
unfilled polymers with a composition similar to the resin matrix.
Studies have shown that the soflex disks which has aluminium oxide
polishing are superior to finish and polish composite restorations.
Indirect composite restorations :
The cured inlays / onlays is primarily trimmed and finished on the
die, using the armamentarium as in a direct composite restoration.
Chair side procedure : at the stage of the restoration, excessive pressure
should not be applied while seating, because of high fragility of composite

14. material. If the restoration dos’t fit in to the cavity, it should be reduced
using disks.
Once the marginal integrity has been established, the occlusion is
then checked and adjusted, occlusal adjustments are made using fine grit
diamond instruments followed by 30 fluted carbide burs. Final adjustments
are made with same instruments and materials as used for direct composite
restorations.
Finishing and polishing of glass ionomer restorations :
The finishing of glass ionomer cement has been described as an
exercise in damage. The ideal surface finish for glass ionomer cements is
produced by the matrix strip and any interference with hand or rotary
instruments inevitably disrupts the surface. However, clinically it is almost
impossible to place a restoration that adequately fills the cavity without
requiring any excess to be trimmed. It is therefore essential to have
satisfactory procedure for finishing.
The surface of glass ionomer cement is sensitive to both dehydration
and water contamination during initial setting phase. If the restoration is
exposed to air during this period without any protective covering like
varnish, it loses water and develops crazing and cracks. Water
contamination on the other hand dissolves the matrix forming ions, resulting
in weak and more soluble restoration. Damage should be avoided by
checking against both these conditions. It is therefore preferable to delay
finishing and polishing of the restoration for at least 24 hrs after insertion so
that setting is complete in case of fast cements and light cure glass ionomer
cement, finishing can be started as early as 10 mins after insertion.
Rotary cutting instruments are preferred than hand cutting
instruments to prevent the tear of the material at the margins. 12 fluted
carbide-finishing burs or fine diamond burs are preferred. Woolford
observed that softex disks with Vaseline produced the smoothest surface. A

15. lubricant such as coca butter or petroleum jelly should be used along with
finishing and polishing instruments.
Finishing and polishing of direct gold restorations :
Burnishing is the first step in finishing a gold restoration. For occlusal
surfaces, a spratley burnisher or ball burnisher is moved with condensable
pressure from the metal to the tooth surface. A spratley blade carver is used
in the embrasure for proximal restorations.
The next step is giving an optimum contour to the restoration.
Instruments used for this purpose include Morse scaler, Jones knife or
cleoid descoid carver. On the occlusal surface, sued from the centre to
margins. In the proximal portions there is a need to remove any excess, if it
exists which is facilitated by tooth separation. Abrasive disks and strips are
used, the disks should be small in diameter to prevent gingival damage.
After the surface has been smoothed, burnishing is repeated once
again on all the margins. Polishing with tin oxide or extra fine silex applied
with a rubber cup gives the restoration a high metallic lustore and satin
finish.
Shofer brown and green cups have also been shown to be very
effective. These rubber cups have an abrasive impregnated in the rubber.
However they should be used only at slow speeds.
Finishing and polishing of cast gold restorations :
An obvious extension of the casting beyond the margins removed
upto the finish line with a small cylindrical point rotating away from the
operator. The remaining thick margin is carefully thinned with fine disks.
Occlusal surface is then finished using abrasive stones and disks in an order
of descending abrasiveness.
The proximal surface is contoured lightly with a ½" to 5/6"
carborundum disk followed by smoothening with medium and fine cattle
paper disks.

16. The occlusion is checked with an articulating paper and premature
contacts, if any are refined with a selective grinding. The roughness created
is then polished with rubber polishing disks or points.
Finally after the insertion of the restoration it is burnished again.
Finishing and polishing of porcelain restorations :
The high esthetic quality of porcelain is attributed to surface texture,
which is characterized by reflection and absorption of light rays.
These are three methods of fabrication currently available for ceramic
inlay and onlays.
i) Conventional filling on a refracting die using firing porcelain,
ii) Milling from a preformed ceramic block using machenable
ceramic and
iii) Casting by the lost wax technique using castable and pressable
ceramic.
The second and third methods do not use the application of a glaze
layer to attain the final surface finish.
i) Restoration formed by firing porcelain :
The desired finish on the fired ceramic restoration is obtained
preferably by glazing and to a smaller extent by polishing. Any adjustment
of the fabricated restoration needs to be done at the expense of the glaze
layer.
It is proven that 40-46% of the strength of the porcelain restoration
will be reduced if the glaze surface is removed. But the strength of a glazed
porcelain and one highly polished are comparable. Hence with the use of
polishing systems like, softex disks, shofu porcelain laminate polishing kit
etc. it is now possible to minimize the damage caused by intra oral
adjustment.
Glazing is of two types autoglazing and overglazing.

17. Autoglazing is a process in which a smooth surface is obtained
without the use of an additional glaze. By careful control of the furnace
temperature (9550
C – 10650
C), a glaze is created. At this temperature the
surface porcelain melts slightly, flows and glazes with a little roundening of
the corners.
Overglazing on the other hand is the application of an external glaze
layer over the surface of the completed body of porcelain. Such a glaze
contains silica and low fusing fluxes and increases translucency.
Chair side finishing procedures
i) Use fine grit diamonds.
ii) 30 fluted carbide finishing burs
iii) Rubber abrasive points and cups at slow speed with air water
spray.
iv) Diamond polishing pastes applied with bristle brush.
ii) Restoration formed by milling ceramic blocks :
These ceramic inlays and onlays are fabricated using CAD-CAM
technology (computer assisted designing and computer assisted
manufacturing).
Diamond finishing burs are used followed by soflex discs to polish
the restoration.
iii) Restorations formed by casting ceramic :
The fabricated restoration is finished and polished on the master die
similarly as described earlier for ceramic restorations.
Hazards of finishing and polishing :
1) High temperature may damage pulp during finishing and
polishing. This raise in temperature may also damage the properties
of restorative material, like bringing mercury to the surface in case of
amalgam restorations.

18. 2) Microstructural defects or cracks can extend below the surface
during finishing and polishing.
3) As finishing proceeds, voids incorporated during the filling
process may be exposed, lodging unsightly stains.
4) The edges of the inflexible disks tend to scratch the surfaces
and the central metallic mounting hub of certain disks also have a
tendency to cut the surface.
5) Restorative materials may be lodged in the oral soft tissues
during finishing and shaping procedures, which can lead to persistent
chronic inflammation of those tissues.
6) Loss of external stains may occur during finishing of castable
ceramic restorations.
7) If attention is not given an excess of glazing could lead to
complete loss of anatomy.
8) And one of the most important complication is the aerosol
production.
i.e. dispersions of solid particles are generated and released into the
breathing space of laboratories and dental clinics whenever finishing and
polishing operations are performed. These airborne particles may contain
tooth structure, dental material and microorganisms. Such aerosols have
been identified as potential sources of infections and chronic diseases of the
eye and lungs and present a hazard to dental personnel and their patients
silicosis also called grinders disease is a major aerosol hazard is dentistry
because a number of silica based materials are used in the processing and
finishing of dental restorations.
Aerosol produced during finishing and polishing can be reduced by
three ways.

19. i) They can be controlled at the source through the use of adequate
infection control procedures, water spray, and high volume
suction.
ii) Personal protection like safety glasses, disposable face masks can
protect the eye and respiratory tract from aerosols.
iii) The entire facility should have a adequate ventilation system.
REFERENCES
1. Finishing techniques for high copper amalgam restoration. A laboratory
study.
Journal of dental research vol – 67, page – 633, 1988.
CONCLUSION
A beautiful statue, even if it is Beautifully sculptured, if left
unfinished will attract no spectators. Similarly a dental restoration without
finishing and polishing will be unesthetic, but this is not the only problem it
will face. The effects are cumulative which will finally lead to its failure. So
why not spend a few more minutes of out precious time finishing and
polishing the restoration rather than see all our hard work go in vain.

20. COLLEGE OF DENTAL SCIENCES
DEPARTMENT OF CONSERVATIVE DENTISTRY
AND ENDODONTICS
SEMINAR
ON
FINISHING AND POLISHING
OF DENTAL MATERIALS
PRESENTED BY :
Dr. SUDHIR BABU S.