1. Care of Dental Restorations
Chapter 43

2. Dental Amalgam Restorations
Margination- Process of removing excess restorative material and applying finishing techniques to re-establish a smooth, well-adapted cavosurface margin. The resultant junction should conform in shape and normal anatomic characteristics.
Finishing-process that involves removing marginal irregularities, defining anatomic contours, and smoothing away surface roughness of a restoration.

3. Dental Amalgam Restorations
Polishing- process carried out after placement of a restoration to remove minute scratches from the surface of a restoration and obtain a smooth, shiny luster. Also applied after other refinishing techniques to produce an unscratched homogeneous surface. Uses abrasive agents to remove roughness, eliminate pits or grooves, and make the surface more resistant to bacterial accumulation.

4. Characteristics of an acceptable finished and polished restoration.
Smooth anatomic contours
Contact areas intact with normal form
Embrasures spaced correctly
Refined margins
Smooth resistant surfaces
Functional effectiveness
Acceptable appearance
No biofilm-retaining irregularities
Restored health of the gingival tissues

9. Indications for use of Margination
Excess interproximal material (i.e., overhang, such as a Class II amalgam restoration) which could cause:
Gingival tissues appearing inflamed in the area
Localized vertical bone loss radiographically or when probing
Dental floss often fraying

10. Benefits of Margination
Removes excess amalgam
Facilitates plaque control
Promotes healthier periodontal tissues
Recreates functional anatomy to the restored tooth surface

11. Instruments that could be used for Margination
Finishing knives
Files
Scalers, curettes, spoon excavators
Cleoid-discoid carvers
Ultrasonic scaler
Finishing discs
Finishing polishing strips

13. Finishing strips
Description: thin, flexible strip of metal (lightening strip), linen abrasive strip or plastic impregnated with abrasive particles on one side.
Available in varying grits,
Extra fine to course

15. Technique to remove a large overhang
Assess the overhang
Use an explorer
Assess the condition of the adjacent gingival tissue to determine ease of access to overhang.
Select instruments based on size of overhang and ease of subgingival access.

16. Technique to remove a large overhang
Initial margination
Use a sharp amalgam or appropriate ultrasonic scaler insert
Secure fulcrum
Angulate the blade/insert so only a small portion of the amalgam will be removed
Use short, overlapping, shaving strokes
Avoid removing too much of the overhang
Smooth with a curette
Finish with an abrasive strip

20. Polishing an amalgam restoration
Use wet polishing agents
Use low speed hand-piece with light intermittent strokes
Avoid cementum
Do not over-polish

22. Rubber cups and points Amalgam polishing kit
Brown and green rubber cups and points have abraisve incorporated in them
Points are used for occlusal
Cups are used for proximal surfaces
Use in this order:
Brown
Green
Sterilize after each use

23. Mounted brushes Soften brushes in warm water Use a fine pumice
Apply agent over the area
Use a slow to moderate speed
Use dental tape to apply to proximal surfaces
Use course to fine abrasive to acquire finish desired
Rinse well

24. Tin oxide Use as final polish -apply with light intermittent strokes
Rinse and evaluate

29. Esthetic restorations
Composite resins
Class I and II posterior direct restorations
Class III, IV, and V anterior direct restorations
Veneeri for teeth that have been intrinsically stained
Filling of diastemas
Improve size or contour of small or mis-shaped teeth
Pit and fissure sealants

30. Characteristics of a composite restoration
Softer to an explorer than enamel or porcelain
Esthetic, tooth colored, but may stain
Highly polishable
Must individualize which polishing agent to use.

31. Polishing a composite restoration
Indications for polishing:
Surface roughness
Surface discoloration
Flash or overhang
Over-filled restorations

32. Polishing a composite restoration
Contraindications include:
Open margins
Fractured restorations
Under-contoured proximal contacts
Large overhangs
Recurrent caries

33. ******
FYI
The use of a plastic matrix strip before polymerization minimizes the amount of finishing required to produce a smooth, regular contoured surface.

34. Contraindications for composite restorations
Use of acidulated phosphate or stannous fluoride
–may cause alteration of the filler particles
-Discoloration of the resin
-avoid mouthrinses containing alcohol
Alcohol may act as a soolvent for the BIS-GMA resin resulting in softening of the material—making it rougher and stain easier.

35. Polishing a composite restoration
Use rubber points (containing abrasives) on a slow-speed handpiece.
Also, can use with aluminum oxide or diamond pastes that contain particles as small as 1 um in diameter to create smooth, reflective surfaces.

36. Microfilled composite resins
Composed of very fine silica filler
Polish very smooth
Possess excellent polishing qualities
Higher luster than hybrid composite resins

37. Microfilled composite resins
Areas used:
Anterior esthetic restorations
Diastema closures
Hand-sculpted composite veneers
Class III and V restorations

38. Microfilled composite resins
Easy to regain surface luster
High surface shine using rubber polishing cups, wheels, and points
Easy to ditch or scratch upon margination
Chips can be modified and stains can be removed with a sequence of finishing discs and strips.

39. Hybrid Composite resins
A mixture of a mix of glass and silica with large, different-sized filler particles.
They can be used where strength and wear resistance are more important than surface luster.

40. Hybrid Composite resins
Class IV anterior restorations
Incisal edges of anterior teeth
Class I or II posterior restorations where there is a moderate stress chewing load.

41. Hybrid Composite resins
More difficult to achieve and maintain a high luster polish
Best strength of all resin categories
Poishable using a diamond-impregnated polisher
Does not polish as smoothly or with as much shine as the microfill composite resins.

42. Compomer
Is a direct esthetic restorative material that is a combination of glass ionomer and composite.

43. Compomer
Used in Class I, II, III, and V restorations in low stress-bearing areas of patients with moderate risk for dental caries.
Buildups or cores for cast crowns
Esthetic repair for fractured or chipped porcelain restorations.

44. Compomer Characteristics
Smoother surface than glass ionomer, but not as smooth as composite resin materials
Best translucency an any of the direct esthetic restorative materials
Releases fluoride similar to glass ionomers
Less wear resistant than composites
Good handling characteristics.

45. Glass ionomer resins
Composed of a polyacrlic matrix filled with aluminosilicate particles.
**The benefit of using glass ionomer restorative material is the release of fluoride to reduce dental caries.

46. Glass ionomer resins Uses: Cements Low stress-bearing restorations
Limited use as Class I and II restorations in the primary dentition
Class I, II, and V restorations on a high caries risk patient where esthetics are not critical

47. Glass ionomer resins Characteristics
Cannot be polishned to the same smoothness as composite resin
Minimal shine
Brittle
Higher incidence of fracture and wear
More opaque—less desirable than other composite resin materials

48. Porcelain Mostly are completed in the laboratory prior to cementation.
Cerec
Longest lasting cosmetic restoration material
When maintained the porcelain restoration can last for many years---if it is not—the restoration can become rough.

49. Porcelain If the porcelain restorative material becomes rough:
Can increase wear of the opposing dentition
Increase the susceptibility to stain and dental caries.
Periodontal inflammation can occur is the gingival margins are not adequately polished.

50. Porcelain High fusing material is used for detnure teeth
Medium fusing material is used for anterior porcelain jacket crowns, ceramic restorations, inlays, onlays and crowns.
Low fusing material is used in porcelain- fused- to- metal crowns.

51. Porcelain Characteristics Mimics tooth color
More esthetic appearance than composite resins
Retains luster
Subject to fracture
Staining

52. Dental hygiene care for porcelain
Gently debride deposits with curets
Avoid the use of a sickle, ultrasonic, or sonic scaler, air polisher, or air abrasive unit.
Consider the use of a plastic instrument instead.

53. Dental hygiene care for porcelain
Use a low-speed handpiece
Special paste for porcelain use
Moisten a soft, flexible rubber cup or felt disc or wheel
Polish for seconds
Dilute the paste with water as the polishing progresses

54. How can the DH identify the restorative material?
Review patient record
Gather patient information
Use tactile detection with a dental explorer
Use air—esthetic restorations may reveal a dry, chalky appearance.

55. Finishing and Polishing Materials
The intent of polishing is to:
create a restorations that fit and maintain occlusal harmony
to produce a smooth surface
Less plaque and calculus adherence
Decrease the potential for the corrosion of metal restoration material.

56. Abrasive procedure
Abrasion is the wearing away or removal of material by rubbing, cutting, or scraping.

57. Finishing
process that involves removing marginal irregularities, defining anatomic contours, and smoothing away surface roughness of a restoration.

58. Factors that affect finishing
Hardness refers to the abrasive’s ability to cut
Size influences the speed of the cut
Larger particles abrade a surface more rapidly.
Particles are classified by size in micrometers(um)
Course = 100 um
Medium = 10 to 100 um
Fine = 0 to 10 um

59. Pressure applied during finishing and polishing
Of the force, when greater, results in more rapid removal of the material.
When greater, creates increased temperature and heat.
Under higher temperatures can lead to distortion or physical changes within the appliance/restoration.
With high temperatures may cause discomfort for the patient because of the transmission of heat to the pulpal tissues.

60. Speed of cup/point/brush during finishing and polishing procedure.
1. When faster, results in faster cutting rates.
When faster, creates greater temperatures.
When faster, creates greater danger of over-cutting the appliance/restoration.

61. Types and composition of abrasives
Diamond
Composed of carbon
Is the hardest substance; is an efficient abrasive because it does not wear down or lose sharpness easily

62. Types and composition of abrasives
Carbides
Include silicon carbide, boron carbide and tungsten carbide
Silicon and boron for finishing instruments typically are supplied as particles pressed with a binder into disks or wheels for use on a hand-piece.

63. Aluminum oxide
Typically is produced as particles bonded to paper disks and strips or impregnated into rubber wheels and points.
Is the abrasive used for white stones—used for polishing of porcelain.
Has fine particles of aluminum oxide and diamond that can be mixed into a paste to produce smooth, polished surfaces on many types of restorations, including acrylics and composites.

64. Zirconium silicate Is a natural mineral
Is used as a polishing agent in strips and disks.
Often is used in prophylactic pastes.

65. Tin oxide
Is used as a polishing agent for metallic restorations, especially amalgams
Produces excellent polish of enamel.

66. Pumice Is a natural glass that is rich in silica
Polishes acrylics and enamel.

67. Rouge
Is iron oxide
Is a powder that can be formed into a block or cake and used on a rag wheel in a dental lathe/handpiece to polish gold alloys.