The hypothesis of this study is; using the tooth disclosing agents by individuals has a positive effect on oral care and as if it is an effective method in improving oral health. Therefore, the aim of this study is to assess the effect of visual guidance of plaque disclosing agents on plaque removal efficacy for patients versus the group of patients evaluated without any tools.

Istanbul Medipol University Faculty of Dentistry 4th grade students are going to be invited to the study. The study will carry out with a total of 124 students. The students who are systemically healthy, drug-free, and at least 20 teeth in the mouth will be included in the study. Smokers, those undergoing orthodontic treatment, the presence of pain or infection that may prevent brushing, pregnant/breastfeeding students, and students who do not agree to participate in the study will not include to the study.

After the initial records (Plaque index and Gingival Index and DMFT- caries, missing teeth due to caries, filled teeth) were obtained, the students in the study will randomly divide into 2 groups:

Group 1; Control Group (n=62) After explaining the Modified Bass Technique and the use of dental floss/interface brush, students will be asked to brush their teeth.

Group 2; Test Group (n=62) After explaining the Modified Bass Technique and the use of dental floss/interface brush, the teeth will stain with a plaque disclosing agent, the plaque is going to be shown in the mirror and then the students will brush their teeth.

Post-operatively, periodontal parameters will be evaluated. Plaque index and gingival index will be measured immediately after brushing, 1 week, 1 months are going to be compared to baseline. A single investigator will make measurements of Gingival Index (GI, Löe and Sillness-1967) and Plaque Index (PI, Sillness and Löe-1964) using a Williams periodontal probe. Measurements will be obtained from 4 surfaces of all teeth (mesiobuccal, midbuccal, distobuccal, midlingual) except third molar teeth, and the values obtained will be summed and averaged, and the average of one tooth. Then, these values will be summed up and averaged, and the mean PI and GI of the individual will be obtained. The outcomes of the two groups will be evaluated by statistical analysis.

The study will be carried out in Istanbul Medipol University Department of Pedodontics, period between October 2023- January 2024. Ethical approval for the study was received from Istanbul Medipol University Ethics Committee. (REF: E-10840098-772.02-2361). The students who agreed to participate in the study will be informed about the study and the written informed consents will be obtained from all participants included in the study.

At the end of the study, 124 students whose measurements were completed will be included in the research. A randomization list was generated using online software (http://www.graphpad.com/quickcalcs/index.cfm), where students enrolled on the study were randomized into 2 groups with an allocation ratio of 1:1. The random allocation sequence was generated by an independent researcher; thus, the operator and observer were blinded to the assignment of the study participants to the groups as follows:

Group 1: Students, whose first records (plaque index, gingival index) are taken after the examination by the periodontology specialist, will be taught how to brush their teeth with the Modified Bass Technique and how to use dental floss/interdental brush. Students will then be asked to brush their teeth.

Group 2: The students, whose initial records (plaque index, gingival index) are taken after the examination by the periodontology specialist, will be taught how to brush their teeth with the Modified Bass Technique and how to use dental floss/interdental brush. After staining the teeth with a plaque disclosing agent, they will be shown in the mirror. Then the students will then be asked to brush their teeth.

Study Design This randomized clinical study will last in three months. According to data from the previous studies, the desired sample size (n=124) was calculated. Among the 204 students who were examined in the beginning, 124 students who met the inclusion criteria will be included in the study to be protected from dropouts.

In the beginning, students are going to fill out an examination form consisting of questions about attitudes of their oral and dental health and the demographic data of the study group. Examination forms consisted of; name-surname, birthdate, examination date, gender, tooth brushing habits (yes or no, and how often they brush their teeth), the use of dental floss and/or an interdental (interface) brush, and how often they use them, the use of mouthwash and/or mouth spray, the last time of they visited a dentist, bleeding of their gums (yes/no). Then, the students will be examined and their DMFT index (decayed, filled, and missing teeth), baseline plaque index and gingival index measurements will be recorded. The students will randomly divide into two groups. All students will be trained about toothbrushing by Modified Bass Technique and the use of dental floss/interface brush by the video presentation and demonstrating with models from the same instructer. Commercially available standard toothpastes will be distributed to students. The students in the control group will be asked to brush their teeth with the technique taught. The teeth of the students in the second group, which is the test group, to stain the teeth Mira 2-tone Solution (Hager&Werken) will be used to visualize dental plaque. After the staining, the students will rinse their mouths with water and the stained tooth surfaces will be shown with the help of hand mirrors. Then the second groups students will brush their teeth with Modified Bass Technique and only the plaque index will be measured again. One week later, the students will be called for control again, and plaque index and gingival index measurements will be repeated in the test group after plaque disclosing and in the control group without disclosing. At the end of one month, the measurements will be repeated in both groups and the data will be recorded.

Gingival Index (GI, Löe and Sillness-1967) and Plaque Index (PI, Sillness and Löe-1964) measurements will be done by a single investigator using a Williams periodontal probe. Measurements will be obtained from 4 surfaces of all teeth (mesiobuccal, midbuccal, distobuccal, midlingual) except third molars, and the values obtained will be summed and averaged, and the average of one tooth; Then, these values will be summed up and averaged, and the mean PI and GI of the individual will be obtained.

The distribution of variables will be analyzed using the Kolmogorov-Smirnov test. Student's t-test and chi-square test will be used to compare the quantitative and qualitative data of the two groups. Spearman's correlation coefficient (R) will be used to evaluate relationships between periodontal status data (PI, GI, DMFT).

Inclusion Criteria:

• Systemically healthy
• Being drug-free
• Have at least twenty teeth in the mouth

Exclusion Criteria:

• Smokers
• Undergoing orthodontic treatment
• Has pain or infection that prevent brushing
• Pregnant/breastfeeding