Comparison of the Effect of Two Oral Hygiene Education Approaches on the Gingival Health and Dental Plaque of Boarding School Students in Fariman, Iran

Introduction

Oral health education plays a key role in oral health promotion (1, 2). Education is a successful approach to improve oral health of adolescents (3, 4). Adulthood behavior is mainly established in adolescence, during which individuals seem more receptive to learning, performing health-related behaviors, and maintaining a positive attitude (5, 6).

There are three main models for oral health education, namely verbal, written, and audiovisual. Audiovisual method seems to be particularly appropriate in adolescents (7). School-based oral health interventions have positively improved oral hygiene, gingival health, and knowledge about oral health (7).Accordingly, schools are settings suitable for assessing the efficacy of different programs of oral health education. Previously, oral health education was mostly provided by dentists and hygienists. However, the cost-effectiveness and durability of this method is questionable (8).

Evidence shows that teachers can more easily and effectively provide and reinforce hygiene content (9, 10). Nevertheless, the lack of time and overload of school assignments are likely to diminish the influence of the oral health education provided by teachers (10). Students can also be employed as a potential resource for school-based health education (11). Moreover, the effects of peer-education can sometimes be more than those of lessons given by trained teachers, hygienists, and even, in some cases dentists (12, 13).

Abdul Haleemet al. (11) reports the higher level of health-improving behavior in peer-led groups compared to that of other groups. Oral health can be considerably improved through student-centered projects. Several studies showed that the oral health education provided by dentists, teachers, and parents exerts more influence than self-led approaches (14, 15). It has also been noted that multidimensional education provided by parents, teachers, and students is far more effective (16).Yazdani et al. (7) observed that school-based interventions can highly improve adolescent’s oral hygiene and gingival health in the short-term, particularly in countries with a developing oral health system .

Although oral diseases are preventable, they still impose great costs on patients and society. No comparisons have yet been made among different approaches for oral health education, particularly in Khorasan Razavi province, Iran. Studies about oral health status of adolescent in Iran are so rare. A study on oral health knowledge, attitude, and practice in adolescents showed that these items obtained the lowest score in Khorasan, compared to the other five provinces of Iran (17).

Furthermore, most of the oral health programs in Iran are implemented in primary schools (7). Therefore, the present study was conducted to compare the efficacy of student-led and teacher-led interventional approaches on the oral health education in order to improve the gingival health status and oral hygiene of high school students.

Materials and Methods

Three boarding all-boys schools were selected from Fariman located in Khorasan Razavi, Iran. The participants were socially, economically, and culturally similar. The students of three schools were randomly divided into self-led (control group), teacher-led, and peer-led groups. The sample size was determined based on a similar previous and the main goal of the study (11). Accordingly, the current study was conducted on a total of 345 students (i.e., 115 participants in each group).

The subjects were enrolled in the present study only after informed written consent forms were obtained from the students’ parents. The exclusion criteria were any physical disability that could prevent satisfactory performance of oral hygiene tasks, as well as periodontitis, which interfered with the precise measurement of the gingival index. All of the students were unaware of the examination day.

In order to randomly determine the intervention method for each school, group names were written on three balls, one of these balls was blindly selected by an individual. Afterwards, the indices of oral hygiene status were measured and recorded for all the samples, including the Plaque Index (PI), Simplified Oral Hygiene Status (OHI-S), as well as the Gingival Index (GI).

The OHI-S was calculated through the sum of two other indicators (debris index and calculus index) on six specific teeth. The index was interpreted based on the intervals of final score, as follows: 0-1.2 (good hygiene), 1.3-3 (moderate hygiene), and 3.1-6 (poor hygiene). The GI was estimated through the computation of four surfaces of six specific teeth and was categorized according to the following intervals: 0 (normal gingiva), 0.1-1 (mild inflammation), 1.1-2 (moderate inflammation), and 2.1-3 (severe inflammation).

The PI is calculated by the computation of four surfaces of six specific teeth and was plotted regarding the following intervals: 0 (Excellent), 0.1-0.9 (good), 1-1.9 (moderate), and 2-3 (poor).

All the pre-and post-intervention examinations were performed by the same examiner, who utilized a mirror, explorer, and flashlight. The required equipment were prepared in separate sterile packages for each student.

Identical educational intervention was conducted by either the teachers or students depending on the kind of group’s intervention. The educational content included a brochure, a pamphlet, and a PowerPoint presentation. The pamphlet explained the correct technique of brushing and flossing, as well as their frequency and appropriate time of application. The brochure explained the significance of oral and dental health and its effect on the health of human body, such as the digestive system. It also included an introduction to deciduous and permanent teeth, intraoral components, and information about the parts of the tooth. In addition, healthy gum characteristics, gingival diseases (gingivitis and periodontitis), dental plaque and its role in developing dental and gingival diseases, the significance of nutrition on oral health, and dental caries were included in the brochure.

The PowerPoint slides presented the brochure content and incorporated interesting pictures for the purpose of training the teachers and the students in the role of educators. The slides were then used for training the subjects. In the teacher-led group, each teacher was assigned to train a group of students. In the student-led group, teachers selected a student from each class to undertake the oral health education. The selection was based on the student’s educational status, interest in oral health education, social communication skills, and discipline. The selected trainers were taught about the intervention content and method during five 2-hour sessions.

The subjects of all three groups received an educational package consisted of the brochure and pamphlet, as well as a soft toothbrush, toothpaste, and dental floss. In the peer-led and teacher-led groups, the educational content was also orally presented by demonstrating a dental arch and toothbrush. The intervention was performed at the beginning of the study and 6 weeks later in 45-60 min sessions.

The trainer attended the classes in the fourth and eighth week and orally presented a summary of the educational content in 5-10 min. On the other hand, the subjects in the self-led group received no educational intervention. According to a similar study (7), the previously-measured indices were clinically re-examined after 3 months. Finally, the overall satisfaction with the oral health education was recorded by asking the students if they were satisfied with the educational program.

The collected data was analyzed in SPSS software (version 19). A paired t-test compared the pre- and post-intervention mean values of each group indices. In addition, the Kuskal-Wallis test compared the indices of three groups. To compare the satisfaction level, the Chi-square test was utilized. P-value less than 0.05 was considered statistically significant. 

Results

In the present randomized interventional study, a total of 345 male high school students of the same socioeconomic status were recruited from three boarding schools in Fariman, Iran. The missing data included the drop-out of 11 participants due to various reasons, such as changing the school. The subjects were examined before and after the intervention. The changes of measured indices in three groups were calculated to assess the effect of educational intervention.

As can be seen in Table I, the results of the paired sample t-test indicated that the intervention significantly affected the mean OHI-S, GI, and PI in all three groups (P<0.001), peer-led (P<0.001),  peer and self-led groups, respectively (P<0.001).

The Kolmogorov-Smirnov test showed that the indices were not distributed normally in all groups (P<0.001). Therefore, the application of Kruskal-Wallis test revealed that the differences of indices were statistically significant among the three groups (Table II). The obtained results of the Mann-Whitney U test showed that there was no significant difference between the peer-led and teacher-led groups in terms of the decrease in the three study indices after the intervention. The scores of three indices were decreased significantly by the peer-led intervention compared to the self-led intervention. Teacher-led intervention decreased OHI-S (P=0.005) and GI (P=0.007) significantly, compared to the self-led intervention.

Finally, the overall satisfaction with the oral health education was reported to be 87.6%, which was the highest and lowest in the teacher and self-led groups, respectively. Moreover, the Chi-square test revealed no significant difference among the study groups in this regard (P=0.8).

Table I. Comparison of mean and standard deviation among three indices in each group by paired t-test

Table II. Comparison of mean differences of final and base line study outcomes among three groups