Bacterial Penetration along Different Root Canal Fillings in the Presence or Absence of Smear Layer in Primary Teeth

To study the effect of the smear layer on the penetration of bacteria along different root canal fillings and to compare the sealing ability of new endodontic material Apexit plus as compared to Zinc Oxide Eugenol (ZOE) in primary teeth. Study design: A total of 60 human root segments were instrumented for endodontic treatment. Half of the sample size was irrigated with normal saline and in other half, 3% NaOCl, 3% H2O2 and 17% EDTA was used alternatively as irrigant during instrumentation. The roots were rinsed thoroughly with distilled water and sterilized by autoclaving for 20 min at 121 ± 2 0 C. Roots with and without smear layer were obturated with Apexit plus, Zinc oxide eugenol. Following storage in humid conditions at 370 C for 2 days, the specimens were mounted into a bacterial leakage test model for 180 days. Results: At 180 days, there is statistically significant difference with a P value of < 0.05 among all groups except ZOE –smear and –nonsmear. In the presence of smear layer, Apexit plus demonstrated more leakage. No leakage was observed in ZOE groups. ZOE demonstrated better sealing ability than Apexit plus. Conclusions: Removal of smear layer helps in better resistance to bacterial penetration along Apexit plus root canal fillings but no effect is seen along ZOE root canal fillings.

Apexit plus, bacterial penetration, smear layer, Zinc oxide eugenol.

1. Saha S, Samadi F, Jaiswal JN, Ghoshal U . Antimicrobial activity of different endodontic sealers: an in vitro evaluation. J Indian Soc Pedod Prev Dent, 28: 251-7, 2010.

2. Johnson WT, Gutmann JL. Pathways of the Pulp. 9th ed. St Louis: Mosby Elsevier, 358–99, 2005.

3. Sundqvist G, Figdor D. Essential Endodontology. 1st ed. Oxford, UK: Blackwell Science Ltd, 253, 1998.

4. McComb D, Smith DC. A preliminary scanning electron microscopic study of root canals after endodontic procedures. J Endod, 1: 238–42, 1975.

5. Lalh MS, Titley K, Torneck CD, Friedman S. The shear bond strength of glass ionomer cement sealers to bovine dentine conditioned with common endodontic irrigants. Int Endod J, 32: 430–5, 1999.

6. Saleh IM, Ruyter IE, Haapasalo M, Ørstavik D. The effects of dentine pre-treatment on the adhesion of root canal sealers. Int Endod J, 35: 859–66, 2002.

7. Reddy S, Ramakrishna Y. Evaluation of Antimicrobial Efficacy of Various Root Canal Filling Materials Used in Primary Teeth: A microbiological Study. J Clin Pediatr Dent, 31: 193-8, 2007.

8. Spedding RH. In complete resorption of resorbable root canal filling in primary teeth: Report of two cases. ASDC J Dent child 52: 214-6, 1985.

9. Apexit Plus, Dental Radiopaque Non-Shrinking Root Canal Sealer Paste. htm [Internet]. [cited 2010 Sep 24].Available from : http://www.directdentalsupplies.com /home- dental office supply

10. Saleh IM, Ruyter IE, Haapasalo M, Ørstavik D. Bacterial penetration along different root canal filling materials in the presence or absence of smear layer. Int Endod J, 41: 32–40, 2008.

11. Pashley DH. Smear layer: physiological considerations. Oper Dent Suppl, 3: 13-29, 1984.

12. Saleh IM, Ruyter IE, Haapasalo M, Ørstavik D. Survival of Enterococcus Faecalis in dentinal tubules after root canal filling with different root canal sealers in vitro. Int Endod J, 37: 193-8, 2004.

13. Pascon FM, Kantowitz KR, Borges AF, Puppin-Rontani RM. Influence of cleansers and irrigation methods on primary root dentin permeability. J Dent Child (Chic), 74: 30-5, 2007.

14. Teixeira CS, Felippe MC, Felippe WT. The effect of application time of EDTA and NaOCl on intracanal smear layer removal: an SEM analysis. Int Endod J, 38: 285–90, 2005.

15. Grossman LI. Sterilization of infected root canals. J Am Dent Assoc, 85: 900-5, 1972.

16. De Quieroz GA, Day DF. Antimicrobial activity and effectiveness of a combination of sodium hypochlorite and hydrogen peroxide in killing and removing Pseudomonas aeruginosa biofilms from surfaces. J Appl Microbiol, 103: 794-802, 2007.

17. Erdemir A, Ari H, Güngüneş H, Belli S . Effect of medications for root canal treatment on bonding to root canal dentin. J Endod, 30: 113–6,2004.

18. Yiu CK, Garcia-Godoy F, Tay FR et al. A nanoleakage perspective on bonding to oxidized dentin. J Dent Res, 81: 628–32, 2002.

19. Lai SC, Mak YF, Cheung GS et al. Reversal of compromised bonding to oxidized etched dentin. J Dent Res, 80: 1919–24, 2001.

20. Eldeniz AU, Erdemir A, Belli S. Shear bond strength of three resin based sealers to dentin with and without the smear layer. J Endod, 31: 293–6, 2005.

21. Rabinowitz Bz. Pulp management in primary teeth. Oral surg Oral med Oral path, 6: 542-50, 1953.

22. Molander A, Reit C, Dahlén G, Kvist T. Microbiological status of rootfilled teeth with apical periodontitis. Int Endod J, 31: 1–7, 1998.

23. Kokkas AB, Boutsioukis ACh, Vassiliadis LP, Stavrianos CK. The influence of the smear layer on dentinal tubule penetration depth by 3 different root canal sealers: An in vitro study. J Endod, 30: 100-2, 2004.

24. Tannure PN, Azevedo CP, Bercelos R, Gleiser R, Primo LG. Long-term outcomes of primary tooth pulpectomy with and without smear layer removal: A randomized split-mouth clinical trial. Pediatr Dent, 33: 3l6-20, 2011.

25. White RR, Goldman M, Lin PS. The influence of the smeared layer upon dentinal tubule penetration by plastic filling materials. J Endod, 10: 558–62, 1984.

26. Kouvas V, Liolios E, Vassiliadis L, Parissis-Messimeris S, Boutsioukis A . Influence of smear layer on depth of penetration of three endodontic sealers: an SEM study. Endod Dent Traumatol, 14: 191–5, 1998.

27. Mutal L, Gani O. Presence of pores and vacuoles in set endodontic sealers. Int Endod J, 38: 690-6, 2005.

28. Holan G, Fuks AB. A comparison of pulpectomies using Zinc oxide eugenol and KRI paste in primary molars: A retrospective study. Peditr Dent, 15: 403-7, 1993.

29. Sadrian R, Coll JA. Long terms follow up on the retention rate of zinc oxide eugenol filler after primary tooth pulpectomy. Pediatr Dent, 15: 249-53, 1993.

30. Stevens RH, Grossman LI. Evaluation of anti microbial potential of calcium hydroxide as an intra canal medicament. J Endod, 9: 372-4, 1983.

31. Chawla HS, Mani SA, Tewari A, Goyal A. Calcium Hydroxide as a root canal filling material in primary teeth: A pilot study. J Indian Soc Pedod Preven Dent, 16: 90-2, 1998.