Figure 1 Representative SEM micrographs at 5000X showing selected samples from the middle and apical thirds representing the different final irrigation activation techniques and corresponding analysis using image J version 1.50e (right). The XP-Endo Finisher NaOCl-EDTA group showing a highly clean canal surface with patent dentinal tubules in the middle and apical thirds, with little debris and some smear plugs in the apical third. The XP-Endo Finisher NaOCl group showing a thick smear layer with no patent dentinal tubules, some debris in the middle third and similar findings in the apical third. The PUI- NSK Varios NaOCl-EDTA group showing a partial clean wall with smear plugs in the middle third, less patent tubules with more smear plugs in the apical third and a thick smear layer with few patent tubules in the apical third. The PUI-NSK Varios NaOCl group showing a thick smear layer with few patent dentinal tubules and debris in the middle thirds, the apical third exhibits a thick smear layer with no patent dentinal tubules.

Group Name

n

Shaping

Activation

Protocols

XP-Endo Finisher NaOCl-EDTA

9

Yes

Yes

Final rinse with 2ml 2.5% NaOCl activated for 1
minute to working length, followed by 2ml distilled
water, and finally 2ml 17% EDTA activated for 1
minute to working length, followed by 2ml distilled
water rinse, then 2ml 2.5% NaOCl activated for 1
minute to working length.

XP-Endo Finisher NaOCl

9

Yes

Yes

Final rinse with 2ml 2.5% NaOCl activated for 1 minute to working length.

PUI NSK Varios 350 NaOCl-EDTA

9

Yes

Yes

Final rinse with 2ml 2.5% NaOCl activated for 1
minute with PUI with Irrisonic using NSK Varios
350 at working length, followed by 2ml distilled
water rinse, then 2ml 17% EDTA activated for
1 minute to working length, followed by 2ml
distilled water rinse, then 2ml 2.5% NaOCl
activated for 1 minute to working length.

PUI NSK Varios 350 NaOCl

9

Yes

Yes

Final rinse with 2 ml 2.5% NaOCl activated for 1
minute with PUI with Irrisonic using NSK Varios
350 to working length.

Table1 Experimental Groups and Protocols

GROUP

Middle Third

Apical Third

 

N

Mean

SD¥

Difference†

P-Value††

N

Mean

SD¥

Difference†

P-Value††

XP-Endo Finisher/NaOCl-EDTA

9

55.8

6.5

 

 

9

44.6

4.5

 

 

      XP-Endo Finisher/NaOCl

 

 

 

54.2

<0.001*

 

 

 

43.7

<0.001*

      PUI-NSK Varios/NaOCl-EDTA

 

 

 

15.2

<0.001*

 

 

 

19.8

<0.001*

      PUI-NSK Varios/NaOCl

 

 

 

50.3

<0.001*

 

 

 

42.5

<0.001*

XP-Endo Finisher/NaOCl

9

1.6

0.2

 

 

9

1

0.2

 

 

      XP-Endo Finisher/NaOCl-EDTA

 

 

 

-54.2

<0.001*

 

 

 

-43.7

<0.001*

      PUI-NSK Varios/NaOCl-EDTA

 

 

 

-39

<0.001*

 

 

 

-23.8

<0.001*

      PUI-NSK Varios/NaOCl

 

 

 

-4

0.077**

 

 

 

-1.2

1.000**

PUI-NSK Varios/NaOCl-EDTA

9

40.6

2.9

 

 

9

24.8

4

 

 

      XP-Endo Finisher/NaOCl-EDTA

 

 

 

-15.2

<0.001*

 

 

 

-19.8

<0.001*

      XP-Endo Finisher/NaOCl

 

 

 

39

<0.001*

 

 

 

23.8

<0.001*

      PUI-NSK Varios/NaOCl

 

 

 

35

<0.001*

 

 

 

22.6

<0.001*

PUI-NSK Varios/NaOCl

9

5.6

0.6

 

 

9

2.2

0.3

 

 

     XP-Endo Finisher/NaOCl-EDTA

 

 

 

-50.3

<0.001*

 

 

 

-42.5

<0.001*

     XP-Endo Finisher/NaOCl

 

 

 

4

0.077**

 

 

 

1.2

1.000**

     PUI-NSK Varios/NaOCl-EDTA

 

 

 

-35

<0.001*

 

 

 

-22.6

<0.001*

Table2 Comparative analysis of final irrigation activation protocols in relation to percentage of smear layer removal at apical and middle canal thirds.

¥ Standard Deviation †Difference of marginal means between groups in relation to canal area ††Post-Hoc Bonferroni analytical comparison between marginal means *Statistical significant difference with a confidence interval of 99.9% (P<0.001) **No statistical significant difference with a confidence interval of 95% (P>0.05)