The goal of this randomized controlled clinical trial is to compare the immediate effectiveness of 3D intra-oral scanners and standard oral hygiene instructions in improving the oral hygiene of 52 subjects. The main question[s] it aims to answer are:

• Does a 3D intra-oral scanner facilitate the improvement of oral hygiene in subjects?
• Does a 3D-rendered image of plaque-stained teeth confer better visualization to subjects?

Prospective Open Cohort study: Patients referred to NUCOHS Periodontology Department will be invited to participate in the study. Included participants will be randomized into the 3D scanner (test) and standard oral hygiene (control) group. Subsequently, both groups will receive personalized oral hygiene instructions before brushing their teeth. The participants will receive plaque disclosing again to compare the differences between baseline and post-intervention.

Routine periodontal parameters will be recorded at baseline and researchers will compare the percentage improvement in full mouth plaque scores to see if the test group performed better than the control group.

A questionnaire will be given to subjects in the test and control group for qualitative analysis.

The study will require 1 visit.

Subjects:

The randomized controlled study will include 52 healthy volunteers from the National University Centre of Oral Health (NUCOHS), Department of Periodontology. The sample size is calculated with the assumption of a large Cohen effect size. The subjects are patients undergoing periodontal therapy in the center. After written informed consent has been obtained, the baseline periodontal parameters will be obtained to assess for inclusion and exclusion criteria. Successfully included participants will be randomized into 2 groups by blinded study team members.

There will be 2 groups:

1. Test (n=26): 3D intra-oral scanning group.
2. Control (n=26): standard oral hygiene instructions (no 3D intra-oral scanning).

Examiner:

• The blinded examiner will perform the baseline examination and the post-intervention examination.
• An unblinded examiner will perform either a) intra-oral scanning and give tailored OHI and OHE using the 3D rendered image or b) give OHI and OHE using conventional models. A standardized protocol for OHI and OHE is given to calibrate the overall instructions given.
• The standardized protocol will include a demonstration of the modified bass technique using a tooth model as well as intra-orally. Interdental brushes (Curaprox) will be fitted according to the size of the interdental gap using the Curaprox Interproximal Access Probe (IAP PROBE). Its use will be demonstrated intra-orally using a hand mirror in both groups.
• Based on the design of the study, there will be no deviation from standard periodontal treatment protocol with the exception that the test group will receive 3D intraoral scanning during oral hygiene education and instructions.
• At the end of the visit, participants from both test and control group will be given a short questionnaire by delegated study team members to evaluate their perspectives on 3D scanning (test) and standard oral hygiene (control).

Results collection:

- The delegated study member will collect the data collected during the clinical periodontal examination that has been recorded during the visit.

Primary outcome: Difference in the full mouth plaque score (%). Secondary outcomes: Participants experience/satisfaction in the test/control group on the given method of oral hygiene instruction.

Inclusion Criteria:

1. Systemically healthy patients (ASA I and ASA II)
2. ≥ 20 teeth, excluding impacted third molars
3. , between ages 21 and 75 years
4. plaque score (PS) ≥ 50%
5. Bleeding on probing ≥ 30% of sites
6. At least 1 molar is present on each sextant
7. Probing pocket depths (PPD) should be ≤ 6 mm (h) Willingness to give consent

Exclusion Criteria:

1. Presence of PPD ≥ 7 mm, excluding the distal of 7s due to impacted wisdom teeth
2. Presence of fixed retainers
3. Presence of fixed orthodontic appliances
4. Pregnant and lactating patients
5. Cognitive impairments
6. Initiation of antibiotic therapy or antiseptic mouth rinse within 2 weeks before the study
7. Patients with known neuromotor deficits e.g. Parkinsonism, Dementia, Alzheimer's Disease
8. Diseases or medications, medications that may affect treatment
9. Heavy smokers ≥ 10 sticks/day,
10. Unwillingness to undergo periodontal treatment
11. Uncontrolled diabetes mellitus and hypertension
12. Teeth with crowns and bridges
13. Unwillingness to undergo the proposed protocol