In-Vivo randomized clinical trial to compare between the clinical performance of fluoride varnish versus MI paste (CPP_ACP) and the PRG- Barrier coat material concerning enamel remineralization, arrest of active early lesions, resolution of inactive incipient lesions and patient satisfaction and motivation with a 9-months follow up using a high resolution Nikon camera with Canon 700D body. Canon EF 100mm f2.8 USM Macro Lens and Nissin MF18 ring flash Canon fit for better illumination. Also, A set of retractors and A set child occlusal mirrors with A contraster for assessment of the remineralization progress of the white spot lesion.

A total of sixty (60) patients with early white spot lesions will be randomly selected to share in this study from the out-patient clinic of pedodontics and orthodontic department, Faculty of dentistry, Ain Shams University.

An informed consent will be signed by the patients and parents before their enrollment in the current study in which the aim of the study, the methodology and possible complications will be clearly described. This research will be reviewed by the research ethics committee, Faculty of dentistry, Ain Shams University. This In-vivo study will aim to evaluate the effectiveness of the SPR-G filler material sealants when compared to the fluoride varnish and the MI paste.

Precise medical, dental and family history will be taken from all patients through a direct interview and diagnostic sheet.

Teeth will be polished using a polishing brush and paste, and dried thoroughly before being examined.

Clinical examination will be done using a dental mirror and aided by the tactile detection of a dental explorer under LED illumination to make sure that the patients fulfill the inclusion criteria, followed by radiographic examination. All examination and follow up procedures will be done by the same operator to ensure standardization.

Patient's Grouping:

Selected patients will be randomly divided into three groups:

• Group (I): patients will receive Fluoride varnish ttt.
• Group (II): patients will receive PR-G Barrier coat
• Group (III): Patients will receive MI Paste (CPP-ACP)

Patients who fail to show up at the follow up examinations will be automatically excluded from the study. Patients who are no longer willing to continue in the study will have the right to quit at any time.

Patient information will be gathered and stored in the patient examination chart of the outpatient clinic, Department of Pediatric Dentistry, faculty of Dentistry, Ain Shams University. All information will be kept as a hard copy and as an electronic one as well. Patient information will be guarded as confidential information that should never be revealed at all times. This file will remain with the investigator during the study.

Outcome measurement:

9 months' in vivo evaluation of functional & biological aspects of the three modalities regarding retention, stability, oral hygiene and patient satisfaction.

Inclusion Criteria:

• Aged 10-16 years old
• Patient is healthy and medically free.
• Moderate to high level of patient cooperation
• Compliance of the primary caregiver
• Moderate to high caries risk
• Completed or in transitional fixed orthodontic treatment
• At least 1 wsl should be present

Exclusion Criteria:

• Poor oral hygiene
• Deeply Cavitated white spot lesions
• Medically Compromised patients.
• Extremely Uncooperative patient or primary caregiver
• Generalized white spot lesions in the mouth

9 months