title: Effect of 16% carbamide peroxide bleaching gel on enamel and dentin surface micromorphology and roughness of uremic patients: an atomic force microscopic study.
abstract: OBJECTIVE
  To investigate the effect of 16% carbamide peroxide bleaching gel on surface micromorphology and roughness of enamel and root dentin of uremic patients receiving hemodialysis using atomic force microscopy (AFM).
  
  
  METHODS
  A total of 20 sound molars were collected from healthy individuals (n=10) and uremic patients (n=10). The roots were separated from their crowns at the cemento-enamel junction. Dental slabs (3 mm x 2 mm x 2 mm) were obtained from the buccal surface for enamel slabs and the cervical third of the root surface for dentin slabs. Dental slabs were then flattened and serially polished up to #2500-grit roughness using silicon carbide abrasive papers. Half of the slabs obtained from healthy individuals and uremic patients were stored in artificial saliva and left without bleaching for control and comparison. The remaining half was subjected to a bleaching treatment using 16% carbamide peroxide gel (Polanight, SDI Limited) 8 h/day for 14 days and stored in artificial saliva until AFM analysis was performed. Statistical analysis of the roughness average (Ra) results was performed using one-way ANOVA and Bonferroni post hoc multiple comparisons test.
  
  
  RESULTS
  The micromorphological observation of bleached, healthy enamel showed exaggerated prism irregularities more than non-bleached specimens, and this observation was less pronounced in bleached uremic enamel specimens with the lowest Ra. Bleached healthy dentin specimens showed protruded peritubular dentin and eroded intertubular dentin with the highest Ra compared to bleached uremic dentin.
  
  
  CONCLUSIONS
  The negative effects of the bleaching gel on uremic tooth substrates are less dramatic and non-destructive compared to healthy substrates because uremia confers different micromorphological surface changes.
authors.affiliation: Associate Professor of Operative Dentistry, Head of Conservative Dentistry Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
authors.forename: Salah Hasab
authors.initials: SH
authors.lastname: Mahmoud
authors.forename: Abeer El Sayed
authors.initials: Ael S
authors.lastname: Elembaby
authors.forename: Ahmed Ragheb
authors.initials: AR
authors.lastname: Zaher
authors.forename: Mohammed El-Awady
authors.initials: Mel-A
authors.lastname: Grawish
authors.forename: Heba M
authors.initials: HM
authors.lastname: Elsabaa
authors.forename: Salwa Abd El-Raof
authors.initials: SA
authors.lastname: El-Negoly
authors.forename: Mohamed Abdel Kader
authors.initials: MA
authors.lastname: Sobh
references.citation: J Adhes Dent. 2008 Oct;10(5):335-8
references.pmid: 19058677
references.citation: Pediatr Nephrol. 2003 Jan;18(1):39-45
references.pmid: 12488989
references.citation: J Endod. 1996 Jan;22(1):23-5
references.pmid: 8618081
references.citation: Quintessence Int. 1989 Mar;20(3):173-6
references.pmid: 2762507
references.citation: Scand J Dent Res. 1993 Aug;101(4):202-9
references.pmid: 8362197
references.citation: Quintessence Int. 2004 May;35(5):411-7
references.pmid: 15130084
references.citation: Med Arh. 2000;54(2):115-8
references.pmid: 10934843
references.citation: J Dent. 2005 May;33(5):363-9
references.pmid: 15833391
references.citation: J Dent. 2005 Aug;33(7):561-7
references.pmid: 16005795
references.citation: Am J Dent. 1995 Feb;8(1):29-32
references.pmid: 7546470
references.citation: Oral Surg Oral Med Oral Pathol. 1983 Aug;56(2):167-73
references.pmid: 6578479
references.citation: J Dent Res. 2005 Mar;84(3):199-208
references.pmid: 15723858
references.citation: Pediatr Nephrol. 2005 Oct;20(10):1388-94
references.pmid: 15947987
references.citation: Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2005 Jun;99(6):689-95
references.pmid: 15897855
references.citation: J Int Assoc Dent Child. 1990 Dec;20(2):54-8
references.pmid: 2130105
references.citation: J Dent. 2008 Jan;36(1):2-7
references.pmid: 18037555
references.citation: Compendium. 1987 Oct;8(9):697-9, 702, 704
references.pmid: 2963695
references.citation: J Esthet Restor Dent. 2003;15(3):166-73; discussion 174
references.pmid: 12859114
references.citation: Quintessence Int. 1993 Jan;24(1):39-44
references.pmid: 8511257
references.citation: J Dent. 1994 Jun;22(3):141-6
references.pmid: 8027456
references.citation: J Prosthet Dent. 1992 Nov;68(5):754-60
references.pmid: 1432795
references.citation: Oper Dent. 2004 Mar-Apr;29(2):219-25
references.pmid: 15088735
references.citation: Quintessence Int. 2005 Jan;36(1):15-24
references.pmid: 15709493
references.citation: J Can Dent Assoc. 2002 Jan;68(1):34-8
references.pmid: 11844416
references.citation: Swed Dent J Suppl. 1996;115:1-45
references.pmid: 8804151
references.citation: Endod Dent Traumatol. 1996 Apr;12(2):82-8
references.pmid: 9028202
references.citation: J Manag Care Pharm. 2007 Dec;13(9 Suppl D):S2-5
references.pmid: 18177212
references.citation: Nephrol Dial Transplant. 2005 Dec;20(12):2587-93
references.pmid: 16204281
references.citation: Crit Rev Oral Biol Med. 2003;14(4):292-304
references.pmid: 12907697
references.citation: Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1999 Sep;88(3):316-9
references.pmid: 10503861
references.citation: Dent Update. 2004 Dec;31(10):608-10, 612-4, 616
references.pmid: 15656076
references.citation: J Endod. 2000 Apr;26(4):203-6
references.pmid: 11199718
references.citation: Acta Odontol Scand. 1999 Dec;57(6):334-41
references.pmid: 10777137
references.citation: Oper Dent. 2001 Nov-Dec;26(6):531-9
references.pmid: 11699174
references.citation: Am J Dent. 2007 Apr;20(2):97-102
references.pmid: 17542203
references.citation: Am J Dent. 2005 Feb;18(1):8-12
references.pmid: 15810474
references.citation: Scand J Dent Res. 1985 Oct;93(5):467-73
references.pmid: 3864220
references.citation: Am J Dent. 2004 Dec;17(6):412-6
references.pmid: 15724752
references.citation: Quintessence Int. 2002 May;33(5):370-5
references.pmid: 12014167