Figure 1 Mean Shear Bond Strength Values of the Different Tested Groups.

Groups

Bleaching Treatment

Antioxidant Treatment

Bonding

1

25% HP

None

Immediately after bleaching

2

25% HP

10% SAS

After Treatment

3

25%

HP

25% SAS

After Treatment

4

25%

HP

10% ATS

After Treatment

5

25%

HP

25% ATS

After Treatment

6

25%

HP

None

After two weeks immersion in artificial saliva

7

None

None

After two weeks immersion in artificial saliva

Table1: Groups used in the study

* HP: Hydrogen peroxide. SAS: Sodium ascorbate solution. ATS: α-tocopherol solution

Groups

Treatment Agent

Composition

PH

2

10% sodium ascorbate solution

sodium ascorbate and water

8

3

25% sodium ascorbate solution

sodium ascorbate and water

8

4

10% α-Tocopherol solution

α-Tocopherol and alcohol

5.5

5

25% α-Tocopherol solution

α-Tocopherol and alcohol

5.5

Table 2: Antioxidants Surface Treatment

 

 

 

N

Mean

SD

Std.

95% Confidence

Min

Max

 

Groups

 

 

 

Error

Interval for Mean

 

 

 

 

 

 

 

Lower

Upper

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bound

Bound

 

 

(1)

 

Im B

10

18.44

4.25

1.34

15.40

21.47

11.52

26.17

(2)

 

10% SAS

10

23.01

5.19

1.64

19.30

26.73

17.06

33.30

(3)

 

25% SAS

10

21.97

5.96

1.88

17.71

26.23

16.53

35.79

(4)

 

10% ATS

10

18.25

4.61

1.46

14.95

21.55

11.12

28.00

(5)

 

25% ATS

10

16.83

4.06

1.28

13.93

19.73

12.09

24.34

(6)

 

Del B

10

31.86

7.86

2.49

26.24

37.49

17.78

41.58

(7)

 

No Bl

10

33.18

9.78

3.09

26.19

40.18

21.62

49.24

 

 

Total

70

23.36

8.61

1.03

21.31

25.42

11.12

49.24

Table 3: Mean, Standard Deviation and Standard Error of Shear Bond Strength of Bleached Enamel to Ceramic Veneers

*Im B: Immediate bonding after bleaching procedure; SAS: Sodium ascorbate solution antioxidant surface treatment; ATS: Alfa-Tocopherol solution antioxidant surface treatment; Del B: Delayed bonding procedure for two weeks after bleaching; No Bl: Bonding to enamel without bleaching.

Group

 

Subset for α = 0.05

 

 

 

1

 

 

 

2

5

16.83

 

 

4

18.25

 

 

1

18.44

 

 

3

21.97

 

 

2

23.01

 

 

6

 

31.86

 

7

 

33.18

 

Sig.

.308

.999

 

Table 4: Post Hoc Tests (Tukey HSD- multiple range tests) Showing the Means in Homogenous Subsets

*group1: Immediate bonding after bleaching procedure; group2:10% Sodium ascorbate solution antioxidant surface treatment; group3: 25% Sodium ascorbate solution antioxidant surface treatment. group4:10% Alfa-Tocopherol solution antioxidant surface treatment. group5:25% Alfa-Tocopherol solution antioxidant surface treatment; group6: Delayed bonding procedure for two weeks after bleaching; group7: Bonding to enamel without bleaching.

 

 

 

 

 

Group

 

 

 

Total

Mode of Failure

1

2

3

4

5

6

7

 

               

Adhesive

% within

70.0%

100.0

100.0

60.0%

60.0%

90.0%

70.0%

78.6%

 

Group

 

%

%

 

 

 

 

 

 

% within

.0%

.0%

.0%

10.0%

10.0%

10.0%

.0%

4.3%

Cohesive

Group

 

 

 

 

 

 

 

 

 

% within

30.0%

.0%

.0%

30.0%

30.0%

.0%

30.0%

17.1%

Mixed

Group

 

 

 

 

 

 

 

 

 

% within

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

Total

Group

%

%

%

%

%

%

%

%

Table 5: Mode of Fracture of the Different Test Groups

*group1: Immediate bonding after bleaching procedure; group2:10% Sodium ascorbate solution antioxidant surface treatment; group3: 25% Sodium ascorbate solution antioxidant surface treatment. group4:10% Alfa-Tocopherol solution antioxidant surface treatment. group5:25% Alfa-Tocopherol solution antioxidant surface treatment; group6: Delayed bonding procedure for two weeks after bleaching; group7: Bonding to enamel without bleaching.