Decreased frequency and duration of tooth brushing is a risk factor for endothelial dysfunction.
BACKGROUND
Periodontal disease is associated with endothelial dysfunction, leading to cardiovascular disease. The effect of detailed tooth brushing behavior, not only frequency but also duration of tooth brushing, on endothelial function is unclear. The purpose of this study was to evaluate the relationships of detailed methods of tooth brushing with vascular function.


METHODS
We evaluated flow-mediated vasodilation (FMD), nitroglycerine-induced vasodilation, and frequency and duration of tooth brushing in 896 subjects. We divided the subjects into three groups according to the frequency and duration of tooth brushing: low frequency and short duration group (<twice/day and <2min/procedure), low frequency or short duration group (<twice/day or <2min/procedure), non-low frequency and non-short duration group (≥twice/day and ≥2min/procedure).


RESULTS
FMD in the low frequency and short duration group was significantly lower than FMD in the low frequency or short duration group and FMD in the non-low frequency and non-short duration group [3.1 (2.7)% vs. 4.2 (3.1)% and 4.7 (3.1)%, P=0.001 and <0.001, respectively]. Nitroglycerine-induced vasodilation was similar in the three groups. Using the non-low frequency and non-short duration group as the reference, the low frequency and short duration of tooth brushing group was significantly associated with an increased odds ratio of a low FMD tertile after adjustment for conventional risk factors (OR: 2.25, 95% CI: 1.39-3.59; P<0.001).


CONCLUSIONS
These findings suggest that low frequency and short duration of tooth brushing are associated with endothelial dysfunction.


BACKGROUND
URL for clinical trial: http://UMIN; registration number for clinical trial: UMIN000003409.
Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Shogo
S
Matsui
Division of Regeneration and Medicine, Medical Center for Translational and Clinical Research, Hiroshima University Hospital, Hiroshima, Japan.
Masato
M
Kajikawa
Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Tatsuya
T
Maruhashi
Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Yumiko
Y
Iwamoto
Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Akimichi
A
Iwamoto
Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Nozomu
N
Oda
Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Shinji
S
Kishimoto
Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Takayuki
T
Hidaka
Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Yasuki
Y
Kihara
Department of Gastroenterology and Metabolism, Institute of Biomedical and Health Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University Hiroshima, Japan.
Kazuaki
K
Chayama
Hiroshima International University, Hiroshima, Japan.
Chikara
C
Goto
Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
Yoshiki
Y
Aibara
Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
Ayumu
A
Nakashima
Division of Regeneration and Medicine, Medical Center for Translational and Clinical Research, Hiroshima University Hospital, Hiroshima, Japan; Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
Kensuke
K
Noma
Department of Oral and Maxillofacial Radiology, Matsumoto Dental University, Shiojiri, Japan.
Akira
A
Taguchi
Division of Regeneration and Medicine, Medical Center for Translational and Clinical Research, Hiroshima University Hospital, Hiroshima, Japan; Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan. Electronic address: yhigashi@hiroshima-u.ac.jp.
Yukihito
Y
Higashi
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001916:Brachial Artery / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D017078:Laser-Doppler Flowmetry / Q000379:methods; D008297:Male; D008875:Middle Aged; D009909:Oral Health / Q000592:standards; D012307:Risk Factors; D013997:Time Factors; D014099:Toothbrushing / Q000379:methods* / Q000592:standards; D014664:Vasodilation / Q000502:physiology*
Endothelial function; Flow-mediated vasodilation; Oral health; Tooth brushing; Vascular structure