Deproteinization Effectiveness on Occlusal Enamel Surfaces and Resultant Acid Etching Patterns: An in vitro Study

Purpose: The goal of this in vitro study was to identify whether occlusal enamel deproteinization is effective in the removal of organic material in order to obtain quality etching patterns using phosphoric acid (H₃PO₄) and sodium hypochlorite (NaOCl) compared to phosphoric acid alone. Study design: Nine extracted third permanent molars were polished with pumice and water. Every pit and fissure was evaluated as a unit, resulting in 40 individual units and then these were divided into five treatment groups. The occlusal enamel surface of each group was subjected to the following treatments: Group 1 (C) Control: No treatment; Group 2 (P): Polish and rinse; Group 3 (PD): Polish, rinse, and sodium hypochlorite (NaOCl) 5.25% for 60 seconds; Group 4 (PA): Polish, rinse, and acid etching with H₃PO₄ 37% for 15 seconds; and Group 5 (PDA): Polish, rinse, sodium hypochlorite (NaOCl) 5.25% for 60 seconds, and acid etching with H₃PO₄ 37% for 15 seconds. Results showed no significant statistical difference in the organic material present between groups 1 (C) (30.18%) and 2 (P) (36.61%), but there was a statistical difference (p <0.002) between Groups 1 and 2, and Group 3 (PD) (16.50%). In the acid etching group, the undesirable Type-III pattern (discussed later) was found in Group 4 (PA) (33.54%), while this was only 7.70% in Group 5, nearly five times more than Group 4, with a significant statistical difference (0.05). When differences were sought for Types I and II etch patterns (discussed later) for Groups 4 and 5, Group 4 (PA) obtained 26.29% (Type I) and 1.75% (Type II) etch patterns, compared to Group 5 (PDA) with 33.4% (Type I) and 38.97% (Type II) etch patterns. Conclusions: The enamel deproteinization technique is an effective way to remove organic material on the occlusal surfaces of teeth, obtaining after phosphoric acid application, up to 72.38% of Types I and II etch patterns. Etching Types I or II can also be determined by the removal of organic material in between enamel crystals.

Enamel, sodium hypochlorite, phosphoric acid, etch pattern, occlusal surfaces

1. Chestnut IG., Schafer F., Jacobson AP., Stephen KW. Incremental suscep-tibility of individual tooth surfaces to dental caries in Scottish adoles-cents. Community Dent Oral Epidemiol 24: 11-16, 1996.

2. Hannigan A., O`Mullane DM., Barry D., Schafer F., Roberts AJ. A caries susceptibility classification of tooth surfaces by survival time. Caries Res 34: 103-108, 2000.

3. Silverstone LM and Dogon IL, St. Paul M N. North Central publishing; 1974:13-39.

4. Espinosa R, Valencia R, Uribe M, Ceja I, Saadia M. Enamel deprotein-ization and its effect on Acid Etching.: An in vitro study. J Clin Pediatr Dent; 33(1):13-20. 2008.

5. Espinosa R, Valencia R, Uribe M, Ceja I, Saadia M; Resin Replica in Enamel Deproteinization and its Effect on Acid Etching J Clin Pediatr Dent; 35(1): 47–52. 2010.

6. Hyatt TP. Prophylactic odontectomy: the cutting into the tooth for the prevention of disease. Dent Cosmos 65: 234-241, 1923.

7. Bodecker CF. Eradication of enamel fissures. Dent Items 51: 859-866, 1929.

8. Buonocore MG. A simple method of increasing the adhesion of acrylic filling materials to enamel surfaces. J Dent Res 34: 849-853, 1955.

9. Cueto EI., Buonocore MG. Adhesive sealing of pits and fissures for caries prevention. J Dent Res 44: 137, 1965.

10. Silverstone LM. The acid etch technique an in vitro studies with special reference to the enamel surface and the enamel resin interface in Proceeding of an International Symposium on Acid etch technique eds

11. Silverstone LM and Dogon IL, St. Paul M N. North Central publishing; 13- 39. 1974.

12. Guba CJ, Cochran MA, Swartz ML. The effect of varied etching and etching solution viscosity on bond strength and enamel morphology. Oper Dent 19: 146-153, 1993.

13. Hobson RS, Rugg -Gunn AJ, Booth TA. Acid –etch patterns on the buccal surface of human permanent teeth. Arch Oral biol; 47:407-412. 2002.

14. Hobson RS, Crotty T, Thomson JM, Jepson NJ. A quantitative study of enamel acid etch patterns on surfaces used for retention of resin bonded fixed prostheses. Eur J Prosthodont Restor Dent; Sep (13):123-128. 2005.

15. Nakabayashi N, Kojima K, Masuhara E. The promotion of adhesion by the infiltration of monomers into tooth substrates. J Biomed Mater Res, 16: 265-273, 1982.

16. Van Meerbeek B, De Munck J, Yoshida Y, et al. Buonocore Memorial Lecture. Adhesion to enamel and dentin: Current status and future chal-lenges. Oper Dent, 28: 215-235, 2003.

17. Silverstone LM., Hicks MJ., Festherstone MJ. Oral fluid contamination of etch enamel surfaces, A SEM study. J Am Dent Assoc 110: 329-332, 1985.

18. Droz D., Schiele MJ., Panighi MM. Penetration and microleakage of dental sealants in artificial fissures. J Dent Child 71: 41-44, 1985.

19. Eliades A., Birpou E., Eliades T., Eliades G. Self-adhesive restoratives as pit and fissure sealants: A comparative laboratory study. Dent Mater 29: 752- 762, 2013.

20. Hara AT., Zero DT. The caries environment: saliva, pellicle, diet and hard tissue ultrastructure. Dent Clin North Am 54: 455-467, 2010

21. McDonald EE., Goldberg HA, Tabbara N, Mendes FM, Siqueira WL., Histatin I resist proteolytic degradation when adsorbed to hydroxyapatite. J Dent Res 90:268-272, 2011.

22. Shore RC., Kirkham J., Brookes SJ, Wood SR., Robinson C. Distribution of exogenous proteins in caries lesions in relation to the pattern of demin-eralization. Caries Res 34: 188-193, 2000.

23. B.F. Gurney and G.W. Rapp A Technic for Observing Minute Changes on Tooth Surfaces, J Dent Res; 25; 367. 1946

24. Ahuja B., Yeluri R . Baliga S., Munshi AK Enamel Deproteinization before Acid Etching – A Scanning Electron Microscopic Observation J Clin Pediatr Dent 35(2): 169–172, 2010

25. Justus R, Cubero T, Ondarza R, Morales F. A new technique with sodium hypoclorite to increase bracket shear bond strength of fluoride releasing resin-modified glass ionomer cements: comparing shear bond strength two adhesive systems with enamel surface deproteinization before etching. Seminars in Orthodontics 16: 66-75,2010.

26. Junqueira T. B., Correa W., Melo M., Quiroga B., Motohiro O., Douglas D. Effects of enamel deproteinization on bracket bonding with conven-tional and resin-modified glass ionomer cements Eur J Orthod Feb 2012

27. Lam A. Increase in Utilization of Dental Sealants. J Contemp Dent Pract, 9 (March 1): 81–87, 2008.

28. Bolaños-Carmona V, Gonzalo-Lopez, et al. Effects of Etching Time of Primary Dentin on Interface Morphology and Microtensile Bond Strength. Dent Mater, 22 (December): 1121–1129, 2006.

29. Wendt LK, Koch G, et al , Replacements of Restorations in the Primary and Young Permanent Dentition. Swed Dent J, 22 (4): 149–55, 1998.

30. Wendt L-K, Koch G, Birkhed D, On the Retention and Effectiveness of Fissure Sealant in Permanent Molars After 15–20 Years: A Cohort Study. Community Dent Oral Epidemiolol, 29 (August): 302–307, 2001.

31. Houpt M, Fuks A, et al, The Preventive Resin (Composite Resin/-Year Sealant) Restoration: Nine-Year Results. Quintessence Int; 25 (March): 155- 159, 1994.

32. Black GV. Limitations of extension for prevention. Dent Summary 1904; 24: 173-177.

33. Lussi A. Hotz P. Die Approximal-und glattfläschenkaries, diagnostik und therapeutische grunsätze, schweiz monatssche zahnmed 105: 1439-43 1995

34. Nganot; Relationship between form of pit and fissures and the primary lesion of caries Dent. Abstr 6:426, 1961.

35. Blackwell RE. Black’s operative dentistry. 9th ed., South Milwaukee: Medico-Dental,238-244. 1955.

36. Gail KA, Gwinett AJ. Three-dimensional pits replicas of fissures and fissures in human teeth scanning electron microscopy Arch Oral Biol 20: 493, 1975

37. Nowak A., Casamassimo P., The handbook of Pediatric Dentistry. 4th Edition.; Oclusal sealants page 107, 2011

38. Guba CJ, Cochran MA, Swartz ML. The effect of varied etching and etching solution viscosity on bond strength and enamel morphology. Operative Dent, 19: 146–153, 1993.

39. Ripa LW., Gwinnett AJ. And Buonocore MG. The “prismless” outer layer of deciduous and permanent enamel. Arch. Oral Biol. 11:41, 1966.