Compositerestoration Operative restoration Lama El Banna

2. Clinical technique of composite restoration
A. Initial clinical procedures,
B. Tooth preparation for composite
C. Restorative technique for composite

3. A-Initial clinical procedures,
1-Local anesthesia1-Local anesthesia - patient is more relaxed- patient is more relaxed
- reduced salivation- reduced salivation
2-Preparation of operating site –2-Preparation of operating site –
clean the operating site with slurry of pumice to remove anyclean the operating site with slurry of pumice to remove any
debris, plaquedebris, plaque , pellicle, and superficial stains .Calculus removal
Prophylaxis pastes containing flavoring agents, or fluorides act
as contaminants and should be avoided to prevent a possible
conflict with the acid-etch technique.
ClinicalClinical techniquetechnique

4. Color varies with translucency,Color varies with translucency,
thickness of enamel and dentin, agethickness of enamel and dentin, age
of the patient, presence of anyof the patient, presence of any
external or internal stainsexternal or internal stains
Different color zones are present -Different color zones are present -
incisal third is lighter andincisal third is lighter and
translucent than cervical third.translucent than cervical third.
Middle third is blend of twoMiddle third is blend of two
3. Shade selection3. Shade selection

5. 1.1. Determine shade at the start of an appointment (before theof an appointment (before the
tooth is subjected to dehydration)tooth is subjected to dehydration)
2. Use either2. Use either natural lightnatural light (not direct sunlight) or a colour(not direct sunlight) or a colour
corrected artificial light source.corrected artificial light source.
3. Drape the patient with a neutral colored cover if clothing is3. Drape the patient with a neutral colored cover if clothing is
brightbright
4. Make4. Make rapid comparisonsrapid comparisons with shade tabs (no more than 5with shade tabs (no more than 5
seconds each viewing) Make the selection rapidly to avoidseconds each viewing) Make the selection rapidly to avoid
eye fatigueeye fatigue

6. • Teeth and shade guide should be wet to simulate
the oral environment.
• The dentin shadedentin shade is usually selected from the
cervical third of the tooth, whereas the enamelenamel
shadeshade is selected from its incisal third.
• To confirm the final shadeTo confirm the final shade, a small increment of
selected composite is placed adjacent to the area to
b restored and then light cured for matching

7. After fabricating the silicone key and before isolating the tooth it
is imperative to choose the shade before the tooth gets
dehydrated. The idea would be to use the minimal amount of
layers needed for such a restoration and to employ the controlled
body thickness technique.

8. Automated Shade SelectionAutomated Shade Selection

9. 4. Isolation of operating4. Isolation of operating
sitesite
- Rubber dam- Rubber dam
- cotton rolls- cotton rolls
- retraction cord- retraction cord

10. 1.1. ConventionalConventional
2.2. Beveled conventionalBeveled conventional
3.3. ModifiedModified
4.4. Box shapeBox shape
5.5. Facial/lingual slotFacial/lingual slot
B- Cavity designs for composite cavity preparationB- Cavity designs for composite cavity preparation

11. Tooth Preparation:Tooth Preparation:
• Tooth preparation is limitedlimited to extent of the defect, that is
extension for prevention, including proximal contact
clearance, is not necessary unless it is required to facilitate
proximal matrix placement.
• ToTo facilitate bondingfacilitate bonding, tooth surface is made rough using
diamond abrasives.
• Pulpal and axial wallsPulpal and axial walls need not to be flat.
• Enamel bevel isEnamel bevel is given in some cases to increase the surface
area for etching and bonding.

12.  LONG BEVEL AND SMOOTH MARGINS A 40 micron diamond
is used to smoothen out the jagged margins of the tooth and
create a smooth bevel at least 2mm beyond the fracture line. This
softens the edges and rounds off the fractured enamel prisms.

13. The situation after the diamond bur has been used. When
one is making the bevel it is best to be made in sun burst
appearance so that the light reflection in the finished
restoration is from a wavy line and not a straight line.

14. A cermic polishing rubber is used to smoothen the
margins further

15. Soflex discs are then used to create a smooth margin
at an angle once again to maintain the bevel

16. This view shows a very smooth margin and the bevel
rather clearly.

17. Similar to that of cavity preparation for amalgam restoration.Similar to that of cavity preparation for amalgam restoration.
A uniform depth of the cavity with 90° cavosurface margin isA uniform depth of the cavity with 90° cavosurface margin is
requiredrequired
INDICATIONSINDICATIONS
1.1. Moderate to large class I and class II restorationsModerate to large class I and class II restorations
2.2. Preparation is located on root surfaces.Preparation is located on root surfaces.
3.3. Old amalgam restoration being replacedOld amalgam restoration being replaced
CONVENTIONALCONVENTIONAL

18. 1.1. Similar to conventional cavitySimilar to conventional cavity
designdesign
2.2. Have some beveled enamelHave some beveled enamel
margins.margins.
INDICATIONSINDICATIONS
1.1. Composite is used to replaceComposite is used to replace
existing restoration.existing restoration.
(class III, IV, V)(class III, IV, V)
2.2. Restore large areaRestore large area
Rarely used for posterior compositeRarely used for posterior composite
restorationsrestorations
BEVELED CONVENTIONALBEVELED CONVENTIONAL

19. • Advantage of enamel bevel-ends of enamel rods are
more effectively etched producing deeper
microundercuts than when only the sides of enamel
rods are etched.

20. 1.1. No specified wall configuration.No specified wall configuration.
2.2. No Specified pulpal or axial depth.No Specified pulpal or axial depth.
3.3. All parameters determined by extent of caries.All parameters determined by extent of caries.
4.4. Conserve tooth and obtain retentionConserve tooth and obtain retention (MICRO MECHANICAL).(MICRO MECHANICAL).
5.5. Scooped out appearanceScooped out appearance
INDICATIONSINDICATIONS
small, cavitated, carious lesion surrounded by enamelsmall, cavitated, carious lesion surrounded by enamel
correcting enamel defects.correcting enamel defects.
MODIFIEDMODIFIED

22. BOX ONLY PREPARATION
• Indicated when only the proximal surface is faulty with no
lesion present on the occlusal surface
• Prepared with either an inverted cone or diamond stone
held parallel to the long axis of tooth crown.
• Initial proximal axial depth - 0.2mm inside DEJ.
• Neither bevel nor secondary retention required.

23. FACIAL OR LINGUAL SLOTFACIAL OR LINGUAL SLOT
1.1. Lesion is proximal but access is possible throughLesion is proximal but access is possible through
facial or lingual surfacefacial or lingual surface
2.2. Cavosurface is 90 or greater.Cavosurface is 90 or greater.
3.3. Direct access for removal of caries.Direct access for removal of caries.

24. Matrix placementMatrix placement
• Two types of matrices are availableTwo types of matrices are available
- Polyester matrix- Polyester matrix
- metal matrix- metal matrix
• Various matrix retainer which can be used areVarious matrix retainer which can be used are
- Tofflemire retainerTofflemire retainer
- Compound supported metal matrixCompound supported metal matrix
- Sectional matrix system- palodent contact matrixSectional matrix system- palodent contact matrix

29. • Polyester matrixPolyester matrix
-- used especially CLASS III, CLASS IV ,CLASS V cavitiesused especially CLASS III, CLASS IV ,CLASS V cavities
AdvantageAdvantage - they allow the light to pass- they allow the light to pass
DisadvantageDisadvantage - they are not rigid and get deform during- they are not rigid and get deform during
placement of rigid material and contact cannot be properlyplacement of rigid material and contact cannot be properly
restoredrestored
• Metal matrixMetal matrix
-- Ultrathin metal matrices .001- .002 inch are usedUltrathin metal matrices .001- .002 inch are used
- Band should be precontoured outside the mouth- Band should be precontoured outside the mouth

30. ETCHING
Syringe for dispensing gel etchant
Applicator tip for liquid etchant
• 30-40% conc. Of phosphoric used(ideally 37%)
• For enamel & dentin for 15 sec and then rinsed off.
• Available as –liquid and gel.
Adhesion

31. Etching ProcedureEtching Procedure

32. ETCHING ENAMEL-
• Affects both prism core and prism periphery.
• Transforms smooth enamel into very irregular surface.
• When fluid resin is applied
to etched surface
Resin penetrates etched surface
Forms resin tags
Basis for adhesion of resin to enamel

34. ETCHING DENTIN-ETCHING DENTIN-
• Affects intertubular and peritubular dentin.
• Removes the smear layer and exposes collagen network to
achieve optimal adhesion to the dentinal surface.
• After rinsing the surface is kept slightly moistened when
dentin is also involved because it allows the primer and
adhesive material to more effectively penetrate the collagen
fiber to form a hybrid layer which is the basis for mechanical
bond to dentin.

35. 35
Hybrid Layer Formation in Dentine
ETCHANTPRIMER
ADHESIVE RESIN
Intertubular
Dentine
Peritubular
Dentine
Dentinal Tubules
Hybrid
Zone
Collagen

36. ETCH 2 mm BEYOND THE BEVELED MARGINSETCH 2 mm BEYOND THE BEVELED MARGINS The tooth is
etched and the adjacent teeth are protected with Teflon tape at this
point in time. Selective etching is advised and in this case 37%
Phosporic acid was used for 30 secs. on the enamel and 15 secs. on
the dentine

37. The etchant is rinsed off for at least 15 seconds. The
dentine is kept moist for adequate bonding.

38. Etching Priming Bonding
Dentistry
VELCRO
(Hook and Loop
Fastener)

39. 39
The Smear LayerThe Smear Layer
~1-5 µm
Bond strength to tooth structure ~2-5 Mpa
Can be altered or removed because It
incorporates microorganisms. In addition, it is
loosely attached to the underlying dentin
providing for a weak joint between the tooth
tissues and the restorative material.
Advantages:
It thus provides a drier surface for adhesion,
Minimizes post-operative hypersensitivity
Preventing the ingress of irritants from the
restorative material to the tubules

40. MMP-2 , 8 and 9

41. In conclusion, the results of this study showed direct evidence of
increased MMP-2 and -9 activities following adhesive application,
regardless of the use of etch-and-rinse or self-etch adhesive systems.
Since the present study design allowed for identification of the exact
MMP isoforms investigated, this evidence confirms that application
of these adhesives substantially increases the dentin-degrading
activity exerted by MMP-2 and -9, indicating that these proteases
may play a direct role in hybrid layer degradation and loss of bond
strength over time.
The generally higher level of activity seen in etch-and-rinse
adhesives compared with self-etching adhesives seems to correlate
with the more rapid destruction of hybrid layers seen in etch-and-
rinse bonds, relative to self-etch adhesives.
However, that difference may be due to the fact that pre-etched
dentin treated with etch-and-rinse adhesives simply exposes more
dentin matrix than occurs with self-etching adhesives

43. RECOMMENDED CLINICAL APPLICATION PROCEDURE
The reported in vivo test were performed with Single Bond (3M) using 2%
Chlorhexidine digluconate solution (CHX) by Proderma, Peracicaba SP, Brazil.
Based on convenience and what was available at our clinics, we selected the 2%
chlorhexidine solution, Consepsis (Ultradent, Inc., South Jordan, UT 84095),
applied it for one minute after etching with 37% phosphoric acid for 15 seconds,
water rinsing thoroughly and drying to moist surface before applying CHX. The
CHX treated surface is again dried to a moist surface followed by the resin
application of adhesive resin like Optibond Solo Plus (Kerr U.S.A., Orange, CA
92867) which we use. In addition, to enhance the bond strength, we recommend
at least two separate coats of the bonding agent resins applied without pooling of
the resins in the prep [29]. Also, air pressure drying is required to evaporate the
solvent out of the bonding resins for 10 seconds between coats and after the last
coat to insure thorough light curing. Better solvent evaporation increases the
degree of cure and prevents excess water absorption by water displacement of
the remaining solvent. This increases bond strength, decreases nano leakage,
hydrolysis of the resin and MMPs attack on the collagen of the hybrid layer with
time [60]. These procedures are design to minimize sensitivity, marginal
staining, or chipping and improve retention of direct bonded composite
restorations.

44. How to Increase the Durability ofHow to Increase the Durability of
Resin-Dentin BondsResin-Dentin Bonds
 September 2011 .Volume 32, Issue 7
 David H. Pashley, DMD, PhD; Franklin R. Tay, BDSc (Hon), PhD; and Satoshi
Imazato, DDS, PhD
 Abstract
 Resin-dentin bonds are not as durable as was previously thought. Microtensile bond
strengths often fall 30% to 40% in 6 to 12 months. The cause of this poor durability is
a combination of the activation of matrix metalloproteinases (MMPs) by weak acids
such as lactic acid released by caries-producing bacteria, and acid-etchants used in
adhesive bonding systems. These acids uncover and activate matrix-bound MMPs.
The other contributing factor is incomplete resin infiltration. If all exposed collagen
fibrils were enveloped by resin, the MMPs would not have free access to water, an
obligatory requirement of these enzymes. Recently, several inhibitors of MMPs have
been added to adhesive primers. Examples include chlorhexidine (CHX),
benzalkonium chloride (BAC), and MDPB, an antibacterial monomer used in a two-
step self-etching primer adhesive. The advantage of MDPB over CHX and BAC is that
it polymerizes with adhesive resins and cannot leach from the hybrid layer. This is an
example of what can be termed a "therapeutic adhesive system" that provides anti-

45. PRIMER or CONDITIONERSPRIMER or CONDITIONERS
• Primers condition the dentin surface, & improve
bonding.
• Acidic in nature
• eg. EDTA, nitric acid, Maleic acid
Functions:-
• Removes smear layer & provides subtle opening of
dentinal tubules.
• Provides modest etching of the inter-tubular
dentine.
• Ensures sufficient wetting to dentin, displace residual
water and sufficiently carry monomer into created
microporosities. Primers are thus called adhesion-

46. Effective primers should contain hydrophilic monomers,
e.g. Hydroxyethyl Methacraylate (HEMA), that have an
affinity for wet dentin and a hydrophobic part that co-
polymerizes with the subsequently applied adhesive resin.
The primer could contain organic solvents, such as
acetone or ethanol.

47. Because of their volatile characteristics, these solvents act
as water-chaser; it displaces water from the dentinal
surface, promoting the infiltration of monomers through
the exposed collagen. A primer application time of at least
15 seconds should be performed to allow proper
interdiffusion of monomers to full depth of demineralized
dentin.

48. Bonding agentsBonding agents
Classified :-
 First generation(1980) – used glycerophosphoric acid
dimethacrylate
provide a bifunctional molecule.
disadvantage – low bond strength.
Eg-NPG-GMA
Second generation (1983)-adhesive agents for composite
resin.
bond strength three times more than before.
disadvantage-adhesion was short term the bond
eventually hydrolysed.
Eg.prisma , universal bond,clearfil,scotch bond

49. Third generation – coupling agent had bond strength to
that of resin to etched enamel.
Disadvantages-use is more complex & require 2-3 application
steps
eg-tenure , scotch bond2,universal bond
Fourth generation-all bond-2 system consists of 2
primers(NPG-GMA and bisphenol dimethacrylate (BPDM) &
an unfilled resin adhesive (40% BIS-
GMA,30%UDMA,30%HEMA)
Fifth generation-single bond adhesive.
advantage- single step application
eg.3M single bond , one step (BISCO)

50. Multiple coats of bonding agent are applied. (Single Bond , 3M
Espe) and after 30 seconds air is blown to let the solvent evaporate
and for thinning the bonding agent. It is applied on all the area that
has been etched and not only on the fractured margin.

51. FRQ
The Next Jungle...
Adhesives
Dental AdhesivesDental AdhesivesDental AdhesivesDental Adhesives

52. FRQ
1960 1970 1980 1990 2000 2010
1st
/ 2nd
Generation
Only bond to enamel, pH
neutral
3rd
Gen.
pH < 7
3-step
Etch&Rinse
2-step
Etch&Rinse
2-step
Self-etch
1-step
Self-etch
1989: Hybrid layer
Dental Adhesives
History
Enamel Etch Concept – Buonocore 1955
N-Phenyl-Glycin-Glycidyl-Methacrylate
Bowen 1965
1983 Scotchbond / 3M
Bis-GMA-PO4-ester
1988 Scotchbond 2 / 3M
Maleic acid/HEMA
1973 Concise
Enamel Bond / 3M

53. 1960 1970 1980 1990 2000 2010
1th
/ 2th
Generation
No etching, pH-neutral
3th
Gen.
pH < 7
3-step
Etch&Rinse
2-step
Etch&Rinse
2-step
Self-etch
1-step
Self-etch
1989: Hybridlayer
Dental Adhesives
History
N-Phenyl-Glycin-Glycidyl-Methacrylate
Bowen 1965
1983 Scotchbond / 3M
Bis-GMA-PO4-ester
1988 Scotchbond 2 / 3M
Maleic acid/HEMA

54. 1960 1970 1980 1990 2000 2010
1th
/ 2th
Generation
No etching, pH-neutral
3th
Gen.
pH < 7
4th
Gen.
Etch&Rinse
5th
Gen.
Etch&Rinse
6th
Gen.
Self-etch
7th
Gen.
Self-etch
1989: Hybridlayer
Dental Adhesives
History
N-Phenyl-Glycin-Glycidyl-Methacrylate
Bowen 1965

55. 1960 1970 1980 1990 2000 2010
1th
/ 2th
Generation
No etching, pH-neutral
3th
Gen.
pH < 7
3-step
Etch&Rinse
5th
Gen.
Etch&Rinse
6th
Gen.
Self-etch
7th
Gen.
Self-etch
1989: Hybridlayer
Dental Adhesives
History
N-Phenyl-Glycin-Glycidyl-Methacrylate
Bowen 1965

56. 1960 1970 1980 1990 2000 2010
1th
/ 2th
Generation
No etching, pH-neutral
3th
Gen.
pH < 7
3-step
Etch&Rinse
2-step
Etch&Rinse
6th
Gen.
Self-etch
7th
Gen.
Self-etch
1989: Hybridlayer
Dental Adhesives
History
N-Phenyl-Glycin-Glycidyl-Methacrylate
Bowen 1965

57. 1960 1970 1980 1990 2000 2010
1th
/ 2th
Generation
No etching, pH-neutral
3th
Gen.
pH < 7
3-step
Etch&Rinse
2-step
Etch&Rinse
2-step
Self-etch
7th
Gen.
Self-etch
1989: Hybridlayer
Dental Adhesives
History
N-Phenyl-Glycin-Glycidyl-Methacrylate
Bowen 1965

58. 1960 1970 1980 1990 2000 2010
1th
/ 2th
Generation
No etching, pH-neutral
3th
Gen.
pH < 7
3-step
Etch&Rinse
2-step
Etch&Rinse
2-step
Self-etch
1-step
Self-etch
1989: Hybridlayer
Dental Adhesives
History
N-Phenyl-Glycin-Glycidyl-Methacrylate
Bowen 1965

59. 1990 2000 2010
3-step
Etch&Rinse
2-step
Etch&Rinse
2-step
Self-etch
1-step
Self-etch
1989: Hybridlayer
Dental Adhesives
Generations

60. FRQ

61. FRQ
Tooth composition
Enamel (wt%) Dentin (wt%)
Minerals 97 %
Homogenous
70 %
Heterogenous
Organic 1 % 20 %
Water 1 % 10 %

62. FRQ
-Straight forward bonding
-Strong acids etch very well
-Surface can be dry
-Resin flows in spaces
-Polymerizes forming strong bond
Bonding to EnamelBonding to Enamel
Etch enamel with 35% phosphoric acid
Enamel etch pattern

63. FRQ
Bonding Mechanism to Dentin
1st, 2nd generation: only bond to etched enamel,
bond to dentin best achieved by sandwich technique
with glass ionomer base
3rd generation: weakly acidic primers partially
dissolve the smear layer and etch dentin – low bond
strength due to inadequate resin systems

64. FRQ
Bond to Dentin – the Hybrid Layer
e.g. 4th Generation
Bonding
Primer
Resin tags
Composite

65. FRQ
The Hybrid Layer
Demineralized, resin-
impregnated dentin
Concept established by
Nakabayashi (1980s)
TEM visualization
techniques by Yoshida and
van Meerbeek (1998)
A – glass filled adhesive resin (Optibond FL)
H – hybrid layer
T – dentin tubule
R – resin tag
I – nondemineralized intertubular dentin
B. van Meerbeek et al., J. Dent. Res. 1998 2 µm

66. FRQ
Etching enamel and dentin (total etch)
Hydrophilic primer wets and penetrates dentin
very well
Hydrophobic bond
Introduced around 1993
First adhesives with high dentin bond strength
Gold standards (Optibond FL, Scotchbond
Multipurpose)
4th Generation Adhesives
44thth
GenerationGeneration
A B
Etch Prime Bond

67. FRQ
Etching enamel and dentin (total etch)
Hydrophilic primer and hydrophobic bond of 4th
generation combined into one bottle
Introduced around 1997
Most popular adhesives in many parts of the world
Examples: Prime&Bond NT, Optibond Solo Plus, Singlebond
2
5th Generation Adhesives
55thth
GenerationGeneration
Etch Prime
+
Bond

68. FRQ
5th Generation Adhesives
Advantages:
Less steps compared to 4th generation
Long clinical history of over 10 years
Disadvantages:
Highest incidence of post-operative sensitivities
Higher technique sensitivity
moisture of etched dentin
thickness of adhesive layer
phase separation
Loss of dentin bond strength over time

69. FRQ
Etched dentin
Bur Cut dentin with smear layer
-More complicated bonding
-Acids demineralize and open
tubules
-Surface is hydrophilic
and must be kept moist
-Requires priming
-Must be completely sealed
to prevent sensitivity
Etched Dentin and Post-
operative Sensitivity

70. FRQ
Smear Layer after Cavity
Preparation
Cavity preparation produces smear layer
Smear plugs close orifices of dentin tubules

71. FRQ
Etching opens Dentin Tubules
Etching with phosphoric acid (and also strong self-
etch adhesives with pH <2) remove smear plugs
Open tubules
(etched bovine
dentin): smear
layer is
removed
Adhesive needs
to close open
tubules
completely!

72. Perfect
Impregnation
No Sensitivity
Unperfected
Impregnation
Nanoleakage
No
Impregnation
Sensitivity
Weak
Hybridization
Microleakage
Resin Impregnation

73. FRQ
WET DRY
MOIST
Right Surface
Moisture
An Issue with Total Etch Adhesives…

74. FRQ
Dull dentin appearance indicates
dehydration
What happens if the tooth surface is overdried?What happens if the tooth surface is overdried?
The collapsed collagen decreases porosity and
reduces adhesive absorption : Increases chance for
sensitivity

75. When speaking about total-etch or 5th
generation adhesives, what dreaded word comes to
mind if they are used improperly: sensitivity.
Why is this the case?
How many of you have wrestled with the moisture issue in bonding situations? How
moist is moist? How wet is wet? How dry is dry?
Getting the right surface moisture is a critical element in past and present adhesive
systems.
Remember, once the dentin surface is etched, probably the most critical factor for high
bond strength attainment pertains to the surface moisture of the tooth. The primary
concern is that we do not over-dry the tooth nor keep excess moisture on the tooth.
•Wet – If excess, pooled water remains on the surface of dentin or enamel, it may dilute primer
or adhesive and inhibit infiltration into the tooth, resulting in low bond strengths.
•Dry – If we bond to enamel alone, it’s ok to dry the surface off completely. But, when bonding
to dentin, drying the dentin will significantly reduce your bond strength and cause sensitivity for
the patient. Therefore it is important to maintain a moist bonding surface.
Now lets take a look at the SEM photographs above. In a dry field (upper right) notice the
lack of collagen fiber compared to the collagen fiber present in the moist field (lower
middle). The collagen layers must be present and available for the adhesive to infiltrate in
order to get a bond in all of the areas between the tubules.

76. FRQ
The tooth surface needs to be moist!The tooth surface needs to be moist!
Expanded collagen is porous and will absorb
adhesive: minimizes post-op sensitivity.

77. To overcome this problem in dentin bonding, two different
approaches can be followed depending on the primer of the
adhesive system.
The first approach, known as the dry bonding technique,
involves air drying of enamel and dentin and applying a
water-based primerwater-based primer capable of re-expanding the collapsed
collagen network.

78. An alternative approach, wet bonding technique, is to leave
dentin moist, thereby preventing any collapse of collagen,
and use a solvent-containing primer, known for its water-solvent-containing primer, known for its water-
chasing capacitychasing capacity. The solvent displaces dentinal water,
thereby carrying the monomers into the opened dentinal
tubules and through the nanospaces of the collagen web. The
solvents of the primer are then evaporated by gentle air-
drying, leaving the active primer monomers behind.

79. FRQ
„Phantom“ Hybrid Layer
Perdigao, 1995
Overetched, overdried dentin
Adhesive resin
Uninfiltrated, collapsed
collagen (removed by
NaOCl)
Resin tags in non-
demineralized dentin

80. FRQ
Consequences of Over-Drying
1. Collapse of collagen network
2. Incomplete infiltration and seal of the etched dentin
3. Fluid movement within collagen leads to post-
operative sensitivities
4. Lower bond strength
5. No protection of the exposed collagen against
degradation
6. Endogenic enzymes (matrix metalloproteinases /
MMPs) are liberated and activated during etching step
7. MMPs are active in incompletely infiltrated dentin and
lead to significant loss of dentin bond strength over a
few months

81. FRQ
How to Minimize POS with 5th
Generation Adhesives
• Isolation with Rubber Dam to prevent contamination
• Do not over etch dentin – apply etchant to enamel first,
then dentin
• Thoroughly rinse off etching gel
• Keep dentin moist after etching – do not dry with air,
but rather blot excess moisture
• Apply adhesive immediately after blotting
• Apply adhesive generously – 2-3 coats
• Do not air thin too aggressively – if all adhesive is blown
away, there is nothing to bond to
• Continue immediately with filling composite

82. FRQ
Self-Etch Adhesives (6th and
7th Gen)
Acidic monomers in formulation to provide etch
pattern for retention and chemical bond (eg MDP,
4-META)
Introduced around 2000 (6th Generation, eg Clearfil
SE Bond, first version of Prompt L-Pop)
Mild SE adhesives (pH >2) / Strong SE adhesives (pH
<2)
Successful in USA, Japan, Western Europe
Ease of use
Low incidence of post-operative sensitivity

83. FRQ
Acidic, hydrophilic primer
Hydrophobic bond
(eg Clearfil SE Bond)
or
Acidic resin and aqueous phase
have to be mixed before application
(eg Xeno III, Adper Prompt L-Pop)
6th Generation Self-Etch Adhesives
A
Etch
+
Prime
Bond
66thth
GenerationGeneration
B

84. FRQ
7th Generation Self-Etch
Adhesives
All components combined into one bottle
Usually „mild – ultra-mild“ (pH > 2)
Fastest growing segment in adhesives market
Intensely researched, but limited clinical evidence
available
Etch
+
Prime
+
Bond
77thth
GenerationGeneration

85. FRQ
Total number of dentists
Number of dentists encountering
post-operative sensitivity
Total number
of post-operative sensitivities
Total number of restorations
placed
Percentage of restorations
with post-operative sensitivity
100
7
26
5572
0.5%
Low POS with Self-Etch Adhesives
Adper Easy Bond Application test
3M ESPE internal data

86. FRQ
Why do Self-Etch Adhesives reduce
Post-Operative Sensitivity?
1. No separate etching step – minimized danger of
overetching and desiccation of dentin
2. Resin penetrates as far as demineralization of
dentin – minimized danger of unimpregnated
collagen layer under adhesive

87. FRQ
Self etch
2 steps
Demineralization Resin
penetration
Risk of
nanovoids
Demineralization
resin penetration
+
- 2 consecutive steps
- risk of nanovoids, if penetration depth
of etchant and resin are not equal
- higher risk of post-op sensitivity
- 1 single step
- no risk of nanoleakage, since
penetration depths are equal
- lower risk of post-op sensitivity
Adper Easy One

88. FRQ
Why do Self-Etch Adhesives reduce
Post-Operative Sensitivity?
1. No separate etching step – minimized danger of
overetching and desiccation of dentin
2. Resin penetrates as far as demineralization of
dentin – minimized danger of unimpregnated
collagen layer under adhesive
3. Adhesive is neutralized by basic hydroxyapatite
during application

89. FRQ
Why do Self-Etch Adhesives reduce
Post-Operative Sensitivity?
1) No separate etching step – minimized danger of
overetching and desiccation of dentin
2) Resin penetrates as far as demineralization of
dentin – minimized danger of unimpregnated
collagen layer under adhesive
3) Adhesive is neutralized by basic hydroxyapatite
during application
4) Mild self-etch adhesives do not dissolve smear
layer completely – most tubules remain protected
by smear plugs

90. FRQ
7th Generation adhesive on dentin
lab-demineralized
dentin
particle-filledparticle-filled
adhesiveadhesive
Clearfil Protect Liner
acid-resistant submicron hybrid
layer
dentin
tubule
smearsmear
plugplug
TEM image courtesy of Prof. van Meerbeek, Univ. Leuven, Belgium

91. FRQ
Van Meerbeek et al.
2009, Dental Materials

92. FRQ
•“3-step etch&rinse adhesives and (mild) 2-step self-etch
adhesives are still the benchmarks
•When bonding to enamel, an etch&rinse approach is definitely
preferred
•When bonding to dentin, a mild self-etch approach is superior,
as it involves (like with glass-ionomers) additional ionic
bonding
•Altogether, … selective etching of enamel followed by the
application of the 2-step self-etch adhesive to both enamel
and dentin currently appears the best choice“
Van Meerbeek et al.
2009 Conclusions

93. FRQ
Bond Strengths
Bart van Meerbeek et al
„Relationship between Bond-strength tests and Clinical Outcomes“
Dent Materials, 2009, 11, 148ff.
“A good correlation (…) was found between the annual failure rates
reported in the systematic review of Peumans et al and the “Battle of the
Bonds” shear-bond strength data from Degrange et al.”
„The significantly highest bond strength was measured
for OptiBond FL (Kerr) that somewhat surprisingly
performed not significantly better than the relatively
new 1-step adhesive Easy Bond (3M ESPE).“

94. FRQ
TEM-Interface Analysis
Dentin (self-etch) - Prof. van Meerbeek

95. FRQ
TEM-Interface Analysis
Cut Enamel (self-etch) - Prof. van
Meerbeek

96. FRQ

98. Composite Placement:Composite Placement:
-- handling of composite material is totally different than that of
amalgam, as composites are not condensablenot condensable because of their puttyputty
consistency tendingconsistency tending to stick to applicators and condensing
instruments.
-Teflon or Gold-plated packing instruments have to be used.
-Dragging and flushing of the composites towards the wallstowards the walls and
margins ofmargins of the cavity during shaping of the restoration, prior to
curing, is mandatory to increase its adaptationincrease its adaptation.
-This can also be done with fine brushes that also smoothens the
composite increment surface.

99. Irrespective of the location of the restoration,
composites should be placed and polymerized in
increments. This ensures complete polymerization of
the whole composite mass and aids in the anatomical
buildup of the restoration.
Each increment should not be more than 2 mm in
thickness, thickness of more than 2 mm is difficult to
cure and result in more polymerization shrinkage
stress.

100. Successive Cusp Build-up Technique:Successive Cusp Build-up Technique:
• The first composite increment is applied to a single dentin
surface without contactingwithout contacting the opposing preparation walls.
• After this restoration, built up is done by placing
wedge-shaped composite increments.
• This technique minimizes the C-factorminimizes the C-factor in three
dimensional tooth preparations.

103. Curing Of the Composite:
The material is cured using the
light curing machine for 5
seconds (LED) or 10 seconds
(Halogen) for every increment
of composite that was placed.

104. Polymerized light should be directed from all sides offrom all sides of
proximal boxproximal box so as to have complete polymerizationcomplete polymerization

105. Finishing and Polishing:
The use of polishers with
enhancers and polishing paste
were done after the trimming of
the excess composites.

106. Finish & polish
Tungsten carbide finishing bur is used
to contour the marginal ridge (note the
water spray).
Rugby ball’-shaped fine diamond is
used to contour the occlusal anatomy.
All high-speed instruments must be
used with water spray.
A flexible, abrasive, impregnated disc is
used to polish and smooth the occlusal
contours.

107. Finishing & Polishing

108. 1.Esthetic.
2.Conservation of tooth structure.
3.Insulative.
4.Bonded to tooth structure.
5.”Command set”
6.Repairable.
7.Can be polished at the same appointment
ADVANTAGES:-

109. Composite restorations are very technique sensitive so
utmost care is necessary before, During and after
manipulation.
The Visible Modes Of Failures
1) Discoloration-Especially At Margins
2) Marginal Fracture
3)Recurrent Caries
4) Post Operative Sensitivity
5) Cross Fracture Of Restoration
6) Lack Of Maintaining Contact
7) Accumulation Of Plaque Around The Restoration

111. 1. PKT3

112. 2. Small ball ended burnisher

114. 4. Microbrush Applicator

115. 5. Finishing Burs : fine and extra fine ( Egg shape-
Flame – Needle )

118. 5-Soflex dics and
holders

119. 6. Abrasive Strips