EVALUATION OF ENAMEL MICROHARDNESS AFTER APPLICATION OF THE PRE-REACTED GLASS IONOMER VARNISH IN PERMENANT TEETH (IN VITRO STUDY)

Introduction: Surface pre-reacted glass ionomer varnish (S-PRG) is a product that contains filler particles incorporated into resin material and promising in arresting pits and fissure caries of permanent teeth.Objectives: Evaluate and compare the micro-hardness of enamel covered by pre-reacted glass ionomer varnish to pits and fissure sealant on freshly extracted permanent teeth.Materials and Methods: Fifteen freshly extracted impacted third molar teeth were selected. Baseline enamel micro-hardness was recorded for each tooth. Squares of self-adhesive labels (4×4 mm) were positioned on the buccal surface of both the mesial and distal half. Each tooth was split longitudinally through the buccolingual surface into two halves, creating thirty specimens distributed randomly into two groups of 15 specimens each: Group I (test group) received S-PRG and Group II (control group) received Fisseal. For five days, each specimen was incubated in an individual container and subjected to 5 pH cycles at 37ºC for 5 days. Immersion in a remineralizing solution was carried out during each cycle for 18 hours (pH = 7), followed by rinsing and re-immersion in a demineralizing solution for 6 hours. Evaluation of surface micro-hardness was conducted after pH cycling for both the test and control groups using Vickers micro-hardness indentation test. Results: A significant difference in hardness was recorded between Group I (S-PRG group) and Group II (pits and fissure sealant group) after pH cycling, with Fisseal showing higher micro-hardness values (P