Table 1 Item content, Factor loading and reliability coefficient of the TPB variables

Attitude

 Protecting oral health makes me feel unbeneficial/beneficial

0.811

 Protecting oral health makes me feel stupid/clever

0.836

 Protecting oral health makes me feel unpleasant/pleasant

0.794

 Protecting oral health makes me feel unenjoyable/enjoyable

0.740

 Protecting oral health makes me feel useless/useful

0.862

 Protecting oral health makes me feel unimportant/important

0.830

 Protecting oral health makes me feel unadvisable/ advisable

0.743

Subjective norms

 My teacher thinks that I should adopt oral self-care behaviors

0.817

 My classmates think that I should adopt oral self-care behaviors

0.838

 My teacher’s opinion of oral health is important

0.826

 My classmates’ opinion of oral health is important

0.808

 I care what my teachers think I should do in oral health

0.627

Perceived behavioral control

 I find it difficult to take care of my teeth due to the lack of school health education

0.859

 I find it difficult to take care of my teeth due to lack of reminders

0.836

 I find it difficult to take care of my teeth due to the lack of oral hygiene awareness

0.856

 I am still confident to complete daily oral health behaviors even if there is no reminder from others

0.661

 I am still confident to complete daily oral health behaviors even I am lack of oral hygiene awareness

0.627

Behavioral intention

 I intend to brush my teeth twice a day in the next 12 months

0.818

 I intend to gargle after eating in the next 12 months

0.843

 I intend to have regular oral examinations in the next 12 months

0.786