The Journal of Contemporary Dental Practice

Register      Login



Volume / Issue

Online First

Related articles

VOLUME 21 , ISSUE 6 ( June, 2020 ) > List of Articles


Effect of Simulated Pulpal Pressure on Knoop Hardness of Two Self-etch Adhesives with Different Aggressiveness

Maryam Firouzmandi, Maryam Firouzmandi, Mina Mohaghegh, Sonia Hessami

Citation Information : Firouzmandi M, Firouzmandi M, Mohaghegh M, Hessami S. Effect of Simulated Pulpal Pressure on Knoop Hardness of Two Self-etch Adhesives with Different Aggressiveness. J Contemp Dent Pract 2020; 21 (6):673-677.

DOI: 10.5005/jp-journals-10024-2845

License: CC BY-NC 4.0

Published Online: 15-10-2020

Copyright Statement:  Copyright © 2020; The Author(s).


Aim: Simulated pulpal pressure (PP) has been shown to affect the bond strength and nanoleakage of different adhesives at dentin interfaces but the effect of simulated PP on polymerization of adhesives has not been studied yet. Furthermore, it has been proposed that strong and mild self-etch adhesives have different polymerization behaviors. This study aimed to evaluate the effect of simulated PP on polymerization of two self-etch adhesives, Adper Prompt L-Pop (APLP) and Adper Easy Bond (AEB), by means of the Knoop hardness test. Materials and methods: Sixty caries-free human molars were used to prepare deep dentin specimens with a mean remaining dentin thickness of 0.9 mm. The specimens were bonded in the absence or presence of PP. The specimens were assigned to four equal groups (n = 15) as follows: AEB/-PP, APLP/-PP, AEB/+PP, and APLP/+PP. Bonding procedures were completed; then the specimens’ hardness was measured with the Knoop test. Data were analyzed with two-way ANOVA and the t test. Results: In the absence of PP, the hardness of AEB was significantly higher than that of APLP (p < 0.001). In contrast, when PP was simulated, the hardness of APLP was higher than that of AEB (p = 0.002). The hardness of AEB was not influenced by the presence of PP (p = 0.153). Simulation of PP resulted in a significant improvement in the hardness of APLP (p < 0.001). Conclusion: The polymerization degree of strong self-etch adhesive was lower compared to mild self-etch adhesive. In the presence of hydrostatic PP, the polymerization degree of strong self-etch adhesive was higher than mild self-etch adhesive. Clinical significance: Dentin moisture caused by positive PP might improve polymerization of strong self-etch adhesives.

  1. Chiba Y, Rikuta A, Yasuda G, et al. Influence of moisture conditions on dentin bond strength of single-step self-etch adhesive systems. J Oral Sci 2006;48(3):131–137. DOI: 10.2334/josnusd.48.131.
  2. Hashimoto M, Ito S, Tay FR, et al. Fluid movement across the resin-dentin interface during and after bonding. J Dent Res 2004;83(11):843–848. DOI: 10.1177/154405910408301104.
  3. Santini A, Miletic V. Quantitative micro-Raman assessment of dentine demineralization, adhesive penetration, and degree of conversion of three dentine bonding systems. Eur J Oral Sci 2008;116(2):177–183. DOI: 10.1111/j.1600-0722.2008.00525.x.
  4. Fukegawa D, Hayakawa S, Yoshida Y, et al. Chemical interaction of phosphoric acid ester with hydroxyapatite. J Dent Res 2006;85(10):941–944. DOI: 10.1177/154405910608501014.
  5. Doozaneh M, Koohpeima F, Firouzmandi M, et al. Shear bond strength of self-adhering flowable composite and resin-modified glass ionomer to two pulp capping materials. Iran Endod J 2017;12(1): 103–107. DOI: 10.22037/iej.2017.21.
  6. Yiu CKY, Pashley EL, Hiraishi N, et al. Solvent and water retention in dental adhesive blends after evaporation. Biomaterials 2005;26(34):6863–6872. DOI: 10.1016/j.biomaterials.2005.05.011.
  7. Tay FR, Pashley DH, Suh BI, et al. Single-step adhesives are permeable membranes. J Dent 2002;30(7-8):371–382. DOI: 10.1016/s0300-5712(02)00064-7.
  8. Shafiei F, Memarpour M, Jowkar Z. Marginal sealing of a porcelain laminate veneer luted with three different resin cements on fluorosed teeth. Int J Esthet Dent 2017;12(1):60–71.
  9. Nunes TG, Garcia FC, Osorio R, et al. Polymerization efficacy of simplified adhesive systems studied by NMR and MRI techniques. Dent Mater 2006;22(10):963–972. DOI: 10.1016/
  10. Van Landuyt KL, Cardoso MV, De Munck J, et al. Optimization of the concentration of photo-initiator in a one-step self-etch adhesive. Dent Mater 2009;25(8):982–988. DOI: 10.1016/
  11. Sauro S, Pashley DH, Montanari M, et al. Effect of simulated pulpal pressure on dentin permeability and adhesion of self-etch adhesives. Dent Mater 2007;23(6):705–713. DOI: 10.1016/
  12. Yuan Y, Shimada Y, Ichinose S, et al. Effect of dentin depth on hybridization quality using different bonding tactics in vivo. J Dent 2007;35(8):664–672. DOI: 10.1016/j.jdent.2007.05.002.
  13. Feitosa VP, Correr AB, Correr-Sobrinho L, et al. Effect of a new method to simulate pulpal pressure on bond strength and nanoleakage of dental adhesives to dentin. J Adhes Dent 2012;14(6):517–524. DOI: 10.3290/j.jad.a25691.
  14. Vachiramon V, Vargas MA, Pashley DH, et al. Effects of oxalate on dentin bond after 3-month simulated pulpal pressure. J Dent 2008;36(3):178–185. DOI: 10.1016/j.jdent.2007.11.011.
  15. Mahdan MH, Nakajima M, Foxton RM, et al. Combined effect of smear layer characteristics and hydrostatic pulpal pressure on dentine bond strength of HEMA-free and HEMA-containing adhesives. J Dent 2013;41(10):861–871. DOI: 10.1016/j.jdent.2013.07.002.
  16. Nunes TG, Ceballos L, Osorio R, et al. Spatially resolved photopolymerization kinetics and oxygen inhibition in dental adhesives. Biomaterials 2005;26(14):1809–1817. DOI: 10.1016/j.biomaterials.2004.06.012.
  17. Sauro S, Pashley DH, Mannocci F, et al. Micropermeability of current self-etching and etch-and-rinse adhesives bonded to deep dentine: a comparison study using a double-staining/confocal microscopy technique. Eur J Oral Sci 2008;116(2):184–193. DOI: 10.1111/j.1600-0722.2007.00518.x.
  18. Van Meerbeek B, De Munck J, Yoshida Y, et al. Buonocore memorial lecture. Adhesion to enamel and dentin: current status and future challenges. Oper Dent 2003;28(3):215–235.
  19. Zhang Y, Wang Y. Effect of reactive and un-reactive substrates on photopolymerization of self-etching adhesives with different aggressiveness. Dent Mater J 2013;32(3):484–491. DOI: 10.4012/dmj.2012-303.
  20. Marcinkowska A, Andrzejewska E. Viscosity effects in the photopolymerization of two-monomer systems. J Appl Polym Sci 2010;116(1):280–287. DOI: 10.1002/app.31491.
  21. Zhang Y, Wang Y. Photopolymerization of phosphoric acid ester-based self-etch dental adhesives. Dent Mater J 2013;32(1):10–18. DOI: 10.4012/dmj.2012-108.
  22. Moszner N, Salz U, Zimmermann J. Chemical aspects of self-etching enamel-dentin adhesives: A systematic review. Dent Mater 2005;21(10):895–910. DOI: 10.1016/
  23. Purk JH, Dusevich V, Atwood J, et al. Microtensile dentin adhesive bond strength under different positive pulpal pressures. Am J Dent 2009;22(6):357–360.
  24. Zhang Y, Wang Y. Effect of application mode on interfacial morphology and chemistry between dentine and self-etch adhesives. J Dent 2013;41(3):231–240. DOI: 10.1016/j.jdent.2012.11.006.
  25. Marchesi G, Frassetto A, Visintini E, et al. Influence of ageing on self-etch adhesives: one-step vs. two-step systems. Eur J Oral Sci 2013;121(1):43–49. DOI: 10.1111/eos.12009.
  26. Moll K, Park HJ, Haller B. Effect of simulated pulpal pressure on dentin bond strength of self-etching bonding systems. Am J Dent 2005;18(5):335–339.
  27. Ozok AR, Wu MK, De Gee AJ, et al. Effect of dentin perfusion on the sealing ability and microtensile bond strengths of a total-etch versus an all-in-one adhesive. Dent Mater 2004;20(5):479–486. DOI: 10.1016/
  28. Perdigao J, Lopes MM, Gomes G. In vitro bonding performance of self-etch adhesives: II–ultramorphological evaluation. Oper Dent 2008;33(5):534–549. DOI: 10.2341/07-133.
  29. Zhang Y, Wang Y. Distinct photopolymerization efficacy on dentin of self-etch adhesives. J Dent Res 2012;91(8):795–799. DOI: 10.1177/0022034512452143.
  30. Wang Y, Spencer P. Continuing etching of an all-in-one adhesive in wet dentin tubules. J Dent Res 2005;84(4):350–354. DOI: 10.1177/154405910508400411.
  31. Hanabusa M, Yoshihara K, Yoshida Y, et al. Interference of functional monomers with polymerization efficiency of adhesives. Eur J Oral Sci 2016;124(2):204–209. DOI: 10.1111/eos.12245.
  32. Feitosa V, Watson T, Vitti R, et al. Prolonged curing time reduces the effects of simulated pulpal pressure on the bond strength of one-step self-etch adhesives. Oper Dent 2013;38(5):545–554. DOI: 10.2341/12-180-L.
  33. Besse V, Derbanne MA, Pham TN, et al. Photopolymerization study and adhesive properties of self-etch adhesives containing bis(acyl)phosphine oxide initiator. Dent Mater 2016;32(4):561–569. DOI: 10.1016/
  34. Silva S, Malacarne-Zanon J, Carvalho R, et al. Effects of potassium oxalate on Knoop hardness of etch-and-rinse adhesives. Oper Dent 2012;37(4):356–362. DOI: 10.2341/09-228-L.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.