Investigating the Effect of Oral Health Education on the Dental Plaque Index

INTRODUCTION

Performing activities related to oral and dental hygiene depends on having knowledge in its field, which leads to creating a strong motivation and finally performing the desired behaviors. Although knowledge is a necessary part of any behavior change, it is often not enough to change behavior [1-4]. According to the efforts in the field of oral health education, the index of decayed, pulled, filled teeth (DMFT) is still high [1, 5]. Therefore, more efforts are needed to improve health education. It is mentioned in a study that it is necessary to change the traditional methods of health education [6-8]. Traditional education has been based on providing information about tooth decay and gum disease and how to brush and floss, and it is expected that this information will change people's behavior and increase the level of health, but considering the high DMFT index. In 12-year-old children, the need to change the method is felt [3].

One of the consequences of not observing oral and dental hygiene is bad breath. Halitosis or bad breath has attracted the human mind for hundreds of years, and in the ancient texts, there are articles about this and its treatment methods. Most adults suffer from bad breath at least occasionally [9, 10]. Halitosis is not a disease, but a sign of a disease in a part of a person's body. The most common cause of bad breath is poor oral hygiene [6, 11-13], for this reason, one of the ways to solve it is to observe oral and dental hygiene [14, 15]. Bad breath may be one of the most important motivational tools to improve oral and dental health, especially in teenagers due to their high sensitivity to social relationships. By focusing on positive behavioral change, adolescents are more intensively involved in oral hygiene and Dentists try to reduce their bad breath [16].

There is a link between bad breath and decreased social relationships, and people with this problem try to distance themselves from others, cover their mouths, or talk less. On many social levels, people do not realize their problem, but the negative effects of bad breath affect their relationships [17, 18]. The higher the amount of bad breath, the worse the mental condition of people [8, 19, 20]. Flossing and brushing teeth as oral health self-care behaviors are considered the most important factors in prevention. However, the amount of use of toothbrushes and dental floss is still low [21, 22]. For this reason, it seems that traditional education has not had much effect, and giving knowledge in the field of caries and gum diseases does not produce a lot of motivation and sustainability to observe oral hygiene, and if knowledge is given about bad breath, maybe the motivation be stronger for oral hygiene.

A Japanese study of junior high school students found that 40% of students had detectable bad breath, which was closely related to the amount of dental plaque, tongue coating, and not eating breakfast. 42% of the students knew about their bad breath and were worried about it [16]. Another study also found that an oral health education program focusing on bad breath prevention was effective as a motivational tool to promote oral health among high school students in Japan. Therefore, embedding such a program in the school's oral and dental health program will be useful for teenagers, and students will clean their mouths with more interest, motivation, and precision [23].

The purpose of this study was to investigate the effect of common oral and dental health education along with creating motivation through teaching topics such as bad breath or tooth decay on oral and dental health indicators.

MATERIALS AND METHODS

The target group in this study was students, three classes from three girls’ schools and three classes from three boys’ schools were randomly selected, and after obtaining informed consent from the parents for their child's participation, the sample subjects were included in the study. First, demographic characteristics and oral health behaviors (number of brushing and flossing times per day) were asked of the volunteers participating in the study. Then dental examinations were performed using the Silness and Loe Index and the presence or absence of bad breath.

To evaluate bad breath, the sensory test method recommended in previous studies [6] was used. The examinee was asked to exhale through the mouth and the examiner determined the presence or absence of bad breath. Two trained people performed examinations on a regular chair with natural light using a mirror and a probe. The two examiners were calibrated before performing the examinations, and the Kappa coefficient between the two examiners was 0.76, which indicates the agreement of the two examiners. To ensure that the groups are the same in terms of the mentioned indicators, the examination form was checked, and due to the absence of significant differences between the three classes, the subjects were included in the study. Exclusion criteria included the presence of known respiratory, digestive, kidney, and liver diseases or acute dental caries.

Common oral hygiene training included brushing and flossing. The first group (bad breath) was given health education and information about bad breath and its causes and treatment was given to the people. The second group (traditional) was given health education, and in addition, information about decay and gum diseases was given to people. As for the third group (control group), only health education was given to them.

To remove the confounders, all samples were given the same soft toothbrush, dental floss, and toothpaste, and they were asked to use them during the study. In addition, examinations were performed at least 1 hour after eating breakfast. To blind the study, the examination was performed by two people and the third person performed the interventions. Plaque index and bad breath were taken from all people at the beginning of the study as a criterion for the level of hygiene. All of them filled out a questionnaire based on demographic characteristics and oral health behaviors. 2 weeks and 2 months after the interventions, the initial examinations were repeated by the previous examiners (first examination: before the intervention, second examination: 2 weeks after the intervention, and third examination: 2 months after the intervention) [24].

In different periods, a decrease in the plaque index was considered a positive change, and an increase in the plaque index or its lack of change was considered a negative change. For data analysis, SPSS version 23 software and chi-square test (Bonferroni adjustment), McNemar, paired t (with a significance level of 0.016), and Kruskal-Wallis (with a significance level of 0.05) were used.

RESULTS AND DISCUSSION

Among 161 students, 109 students (67%) had bad breath and 52 students (33%) did not have it. 52 of the girls (68%) and 57 of the boys (67%) had bad breath and no statistically significant difference was found between the two sexes.

According to the chi-square (to compare percentages) and Kruskal-Wallis (to compare averages) statistical tests and Table 1, it can be seen that there is a statistically significant difference between different groups in terms of gender, the prevalence of bad breath, and the average plaque score. It does not exist before the intervention and the groups are the same (P-value = 0.05).

Table 1. The percentage and number of different variables of gender, bad breath, and the average score of plaque and gums in different groups before the intervention.

In addition, based on the Paired t-test and Table 2, it was found that in all three groups, the average plaque score decreased significantly within two weeks. However, the plaque score has continued to decrease significantly only in the bad breath group within two months.

Table 2. Comparison of the average plaque score at three time points in three groups.

In addition, according to the chi-square and McNemar test, it can be seen that two months after health education (third examination), in the group that had initial bad breath, bad breath education was found to be more effective than health education alone (P-value = 0.01). Also, two months after health education, regardless of the presence or absence of bad breath, there was a statistically significant difference between the bad breath group (P-value = 0.005) and the traditional group (P-value = 0.013) with the control group, but no statistically significant difference was reported between bad breath training and traditional training. According to the results, two weeks after health education (second examination), in the group that did not have bad breath, the type of training did not show a statistically significant difference, while during the third examination compared to the second examination, bad breath training was It was significantly (P-value = 0.006) more effective than health education alone. In general, health education has been effective in any way, and with time, its effect has decreased significantly in the traditional group (P-value = 0.012) and the control group (P-value = 0.014). In people who did not have bad breath, the effect of health education during the third examination compared to the second examination had a significant drop (P-value = 0.045).

In addition, according to the McNemar test and Bonferroni adjustment chi-square, as well as Table 3, it can be seen that in general, the behavior change of boys was more stable than that of girls (P-value = 0.004). Especially in the traditional group (P-value = 0.001) and control group (P-value = 0.016). Traditional education (P-value = 0.003) or bad breath education (P-value = 0.002) has been more effective than health education alone among girls. Two weeks after health education (second examination), traditional education among Girls was more effective than health education alone (P-value = 0.015), but at the time of the third examination compared to the second examination, these positive changes dropped sharply in the two traditional groups, so that bad breath education compared to the traditional education (P-value = 0.001) and health education alone (P-value = 0.003) was recognized as more effective.

Table 3. Changes in the number plate of three groups, considering gender at different times.