Comparative evaluation of fl uoride release and recharge of pre-reacted glass ionomer composite and nano-ionomeric glass ionomer with daily fl uoride exposure: An in vitro study.

Aim: This in vitro study was designed to investigate the effects of daily fl uoride exposures on fl uoride release and recharge by prereacted glass ionomer (PRG) composite and nano-ionomeric glass ionomer. Materials and Methods: Seventy-two specimens (36 of each material) were prepared and by placing the restorative materials into Tefl on mold. Each specimen was subjected to one of three daily treatments (n = 12): (1) No fl uoride treatment (control); (2) application of a fl uoride dentifrice (1,000 ppm) once daily; and (3) the same regimen as (2), plus immersion in a 0.05% sodium fl uoride (NaF) mouth rinse (225 ppm) immediately following the dentifrice application. Specimens were suspended in a storage vial containing 10 ml demineralizing solution for 6 h and transferred to a new test tube containing 10 ml remineralizing solution for 18 h. Fluoride treatments of the specimens were completed every day prior to their immersion in the demineralizing solution. Media solutions were buffered with equal volumes of total ionic strength adjustment buffer (TISAB) II; fl uoride levels were measured using a digital ion analyzer and fl uoride electrode throughout the 21 day duration of the experiment. Results: Nano-ionomeric glass ionomer showed a better amount of fl uoride release than PRG composite irrespective of the fl uoride treatment supplementation (P < 0.01). Additional fl uoride supplementation improved fl uoride release and recharge ability for both the materials when compared to their respective control groups. The fl uoride recharge for both materials did not show any sustained pattern of release. Conclusion: Nanoionomeric glass ionomer demonstrated a greater ability to release and recharge compared with that of PRG composite. [ABSTRACT FROM AUTHOR]