Effect of 16% carbamide peroxide bleaching gel on enamel and dentin surface micromorphology and roughness of uremic patients: an atomic force microscopic study.
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.
Mahmoud
Salah Hasab
SH
Associate Professor of Operative Dentistry, Head of Conservative Dentistry Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
Elembaby
Abeer El Sayed
Ael S
Zaher
Ahmed Ragheb
AR
Grawish
Mohammed El-Awady
Mel-A
Elsabaa
Heba M
HM
El-Negoly
Salwa Abd El-Raof
SA
Sobh
Mohamed Abdel Kader
MA
J Adhes Dent. 2008 Oct;10(5):335-8
19058677
Pediatr Nephrol. 2003 Jan;18(1):39-45
12488989
J Endod. 1996 Jan;22(1):23-5
8618081
Quintessence Int. 1989 Mar;20(3):173-6
2762507
Scand J Dent Res. 1993 Aug;101(4):202-9
8362197
Quintessence Int. 2004 May;35(5):411-7
15130084
Med Arh. 2000;54(2):115-8
10934843
J Dent. 2005 May;33(5):363-9
15833391
J Dent. 2005 Aug;33(7):561-7
16005795
Am J Dent. 1995 Feb;8(1):29-32
7546470
Oral Surg Oral Med Oral Pathol. 1983 Aug;56(2):167-73
6578479
J Dent Res. 2005 Mar;84(3):199-208
15723858
Pediatr Nephrol. 2005 Oct;20(10):1388-94
15947987
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2005 Jun;99(6):689-95
15897855
J Int Assoc Dent Child. 1990 Dec;20(2):54-8
2130105
J Dent. 2008 Jan;36(1):2-7
18037555
Compendium. 1987 Oct;8(9):697-9, 702, 704
2963695
J Esthet Restor Dent. 2003;15(3):166-73; discussion 174
12859114
Quintessence Int. 1993 Jan;24(1):39-44
8511257
J Dent. 1994 Jun;22(3):141-6
8027456
J Prosthet Dent. 1992 Nov;68(5):754-60
1432795
Oper Dent. 2004 Mar-Apr;29(2):219-25
15088735
Quintessence Int. 2005 Jan;36(1):15-24
15709493
J Can Dent Assoc. 2002 Jan;68(1):34-8
11844416
Swed Dent J Suppl. 1996;115:1-45
8804151
Endod Dent Traumatol. 1996 Apr;12(2):82-8
9028202
J Manag Care Pharm. 2007 Dec;13(9 Suppl D):S2-5
18177212
Nephrol Dial Transplant. 2005 Dec;20(12):2587-93
16204281
Crit Rev Oral Biol Med. 2003;14(4):292-304
12907697
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1999 Sep;88(3):316-9
10503861
Dent Update. 2004 Dec;31(10):608-10, 612-4, 616
15656076
J Endod. 2000 Apr;26(4):203-6
11199718
Acta Odontol Scand. 1999 Dec;57(6):334-41
10777137
Oper Dent. 2001 Nov-Dec;26(6):531-9
11699174
Am J Dent. 2007 Apr;20(2):97-102
17542203
Am J Dent. 2005 Feb;18(1):8-12
15810474
Scand J Dent Res. 1985 Oct;93(5):467-73
3864220
Am J Dent. 2004 Dec;17(6):412-6
15724752
Quintessence Int. 2002 May;33(5):370-5
12014167