Effect of different concentrations of community water fluoride on composite resin: Field emission scanning electron microscopy and energy-dispersive X-ray analysis.

Aim: This study examines how differing fluoride levels in community water affect dental composite resins' surface morphology and elemental composition, utilizing field emission scanning electron microscopy (FESEM) and EDX analysis. Materials and Methods: A total of 30 specimens (15 natural teeth and 15 composite resin samples) were fabricated using an 8 mm × 2 mm Polylactic acid (PLA) mold. The composite resin was applied in 1 mm layers and light-cured for 20 s each. Each group (n = 15) was divided into three subgroups: five were immersed in distilled water at 37°C for 24 h; five in 5 ppm NaF at 37°C for 20 days (changed daily); and five in 100 ppm NaF under the same conditions. After immersion, the specimens were rinsed, dried, and light-cured to ensure complete polymerization. All samples were pulverized for FESEM and EDX analysis. Results: The samples stored in distilled water exhibited minimal visual changes or weight loss. Hydrolytic degradation and slight Triethylene glycol dimethacrylate (TEGDMA) leaching were noted in composites containing barium boro-aluminosilicate glass and silica fillers. Exposure to 5 ppm NaF resulted in minor surface alterations without significant weight change. However, 100 ppm NaF immersion caused pronounced visual surface damage and marked weight reduction, especially in composites with strontium glass fillers. High-fluoride conditions accelerated resin matrix degradation and TEGDMA leaching, leading to reduced mechanical strength and compromised structural integrity. Conclusion: FESEM and EDX findings indicate that elevated fluoride concentrations intensify degradation of composite resins. Monitoring fluoride levels in community water supplies is vital to ensure the longevity and durability of dental restorations.