Dental caries is the primary cause of tooth loss and oral diseases. Dental decay is a continuous pathological process with loss of tooth minerals, demineralization, which involves the destruction of tooth structure from acids. The first sign of early active demineralization is white spot lesions (WSLs) on the tooth surface, meanwhile, subsurface active mineral decomposition.

Deposition of minerals depends on the equilibrium between demineralization and remineralization which may happen as a natural repair mechanism. The aim of this trial is to comparatively evaluate the efficacy of surface pre-reacted glass filler (S-PRG) Barrier Coat coating material against the Icon resin infiltration in the ability to improve the caries lesion state of the WSLs along 1 year. Laser fluorescence was used to compare the two materials to evaluate the caries progression. PRG Barrier Coat group showed immediate significant improvement in LF scores in demineralization progress and inhibition of caries progression with a significant improved effect. S-PRG Barrier Coat was clinically successful strategy in inhibition of caries and improve remineralization.

Inclusion Criteria:

• Patients within 20-40 years of age.
• Each patient has 4 or more WSLs.
• Mild and moderate WSLs according to Gorelick's scale.
• Good oral hygiene and willing patients who can attend the study visits.
• a Symmetrical number of permanent teeth in each arch (mesial to second molars).

Exclusion Criteria:

• Active carious lesions.
• Facial surface restorations.
• Intrinsic and extrinsic stains.
• Patients who have a significant medical history or if they smoke.
• Criteria for discontinuation; Mortality and acquiring severe debilitating disease