Guidelines proved that arresting and remineralization of the root surface caries is better than weakening the tooth structure and restoring it. Manufacturer claims that PRG Barrier Coat effectively treats dental hypersensitivity by providing immediate and long-lasting relief. Also has the effect of eliminating the activity and sur-vival of pathogenic bacteria and hardening the dentin tissue of the affected areas.

A light-cured varnish with extended protection time of up to 6 months, PRG barrier coat incorporates proprietary GIOMER tech-nology, "Surface Pre-Reacted Glass" for high fluoride release and re-charge, continuous release of fluoride, strontium, boron, sodium, aluminum, and zinc, acid neutralization and anti-plaque benefits with excellent self-adhesive abilities. The new material could be an alter-native to SDF varnish in root caries arrest to overcome its unfavor-able color and taste.

Products containing S-PRG fillers have been developed in a wide variety of areas such as tooth surface coating materials, seal-ants, restoration resins and dentifrices. The use of these materials is also expected to have the effect of improving the properties of enamel. In this seminar, we will introduce a new caries prevention using S-PRG filler The eluted ions from the S-PRG filler containing materials exhibit various functions, such as prohibition of biofilm attachment, anti-demineralization, remineralization, modification of apatite crystal, and acid-buffering effect. Each ion was confirmed its function. Par-ticularly, Strontium, Borate and Fluoride ions were involved during calcium phosphate nucleation to form modified nano-hydroxyapatite. The acid buffering effect was shown with the borate ion. As the results of those effects of ions, the various materials with S-PRG technology were proven to con-tribute to increase the acid resistance and the caries prevention.

Inclusion Criteria:

• Teeth with primary root surface caries (active dentin carious le-sions)
• Teeth with gum recession.
• Teeth are vital according to pulp-sensitivity tests.
• Controlled gingival or periodontal conditions.

Exclusion Criteria:

• Retained deciduous teeth; as the research is targeting only per-manent teeth.
• Teeth with previous restorations which may add another varia-ble to the study (type of old restorative material, extent of re-current caries).
• Spontaneous pain or prolonged pain after sensitivity tests (cold and electrical tests) indicating irreversible pulpitis.
• Negative sensitivity tests, periapical radiolucencies, and sensi-tivity to axial or lateral percussion indicating pulp necrosis.
• Teeth presenting external or internal resorption, with adverse pulpal reactions which may affect the outcome of the study.