Tooth bleaching with low-temperature plasma
lowers surface roughness and Streptococcus
, S.-M. Ok
& G.-C. Kim
Department of Dental Hygiene, Kangwon National University, Samcheok;
Department of Oral Medicine, Institute of
Translational Dental Sciences, Pusan National University, Yangsan;
Dental Research Institute, Pusan National University
Dental Hospital, Yangsan; and
Department of Oral Anatomy, School of Dentistry, Pusan National University, Yangsan, Korea
Nam S-H, Ok S-M, Kim G-C.
Tooth bleaching with low-
temperature plasma lowers surface roughness and
Streptococcus mutans adhesion. International Endodontic
Journal, 51, 479–488, 2018.
Aim To evaluate the structural–morphological
changes in enamel surface roughness and Streptococ-
cus mutans adhesion after tooth bleaching using
plasma in combination with a low concentration of
15% carbamide peroxide (CP).
Methodology Sixty pairs of premolars were ran-
domly assigned to the treatment groups (n = 30; buc-
cal surface, groups 1A/2A) or controls (n = 30;
palatal surface, Groups 1B/2B). Group 1A received a
low concentration of 15% CP and low-temperature
plasma. Premolars in group 1B were placed in phos-
phate-buffered saline and served as controls. The buc-
cal surface of Groups 2A was subjected to 15% CP
alone, whilst the palatal surface was subsequently
immersed in PBS (group 2B). After bleaching, all
teeth were soaked for 1 h in artiﬁcial saliva at 37 °C.
Subsequently, teeth were placed in brain–heart infu-
sion with S. mutans at 37 °C for 24 h. The
assessment of the structural–morphological changes
was carried out using a bioﬁlm assay, scanning elec-
tron microscopy and atomic force microscopy. Statisti-
cal analysis of the data was performed with the SPSS
(SPSS Inc., Version 18.0, Chicago, IL, USA). The
Student’s t-test was used to determine whether there
was a signiﬁcant difference in the structural–morpho-
logical effects with and without plasma.
Results Signiﬁcantly less S. mutans adhesion was
observed in group 1A compared with the other
groups (P < 0.05). Moreover, the surface roughness
was signiﬁcantly greater in group 2A compared with
the other groups (P < 0.05).
Conclusions The application of plasma did not
result in any structural–morphological and topo-
graphic changes in the enamel. The combined bleach-
ing method using plasma and a low concentration of
15% CP was less destructive, particularly with respect
to tooth surface changes.
Keywords: dental enamel, low-temperature
plasma, Streptococcus mutans, structural–morphologi-
cal, surface roughness, tooth bleaching.
Received 17 April 2017; accepted 7 September 2017
The acidic property of bleaching agents has the
potential to cause adverse effects on enamel surfaces
(Hairul Nizam et al. 2005). Several studies have
reported that the penetration of bleaching agents into
enamel inﬂuences its microhardness, structure and
morphology (Bitter 1998, Lee et al. 2006, Bistey
et al. 2007). The increase in surface porosity is
Correspondence: Gyoo-Cheon Kim and Soo-Min Ok, Depart-
ment of Oral Anatomy and Cell Biology, School of Dentistry,
Pusan National University, Beomeo-ri, Mulgeum-eup, Yang-
san-si, Gyeongsangnam-do, 50612, Korea
(Tel.: +82-51-510-8243; fax: +82-51-510-8241;
e-mails: email@example.com (G.-C.K.); oksoomin@pusan.
S.-M. Ok contributed equally to this work.
International Endodontic Journal
, 51, 479–488, 2018
© 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd