• Sawat Pojlerdarun D.D.S.
• Rangsima Sakoolnamarka D.D.S., Grad Dip in Oper Dent, Ph.D.

Objective To investigate the effect of CPP-ACP and Novamin on citric acid erosion resistance of
pellicle-covered enamel.

Materials and methods Thirty-six human enamel samples, 2 x 2 x 2 mm³ in size, were covered
by pellicle from storing in oral cavity of one healthy volunteer for 2 hours. Subsequently, enamel
samples were divided into 3 groups (each group n = 12); control, CPP-ACP and Novamin groups.
CPP-ACP or Novamin was applied on enamel surfaces for 3 minutes then rinsed with de-ionized
water. Then, all samples were immersed in 1 ml of citric acid (1%) for 60 s. Calcium ions released into
the acid solution were measured using icp-optical emission spectroscopy. The specimens were
observed using scanning electron microscopy.

Results Mean values (standard deviations) for the released calcium ions (milligrams per liter)
from the control, CPP-ACP and Novamin groups were 23.65 (7.80), 29.76 (6.55), and 45.90 (9.61),
respectively. The Novamin group had significantly higher mean value than the control group and the
CPP-ACP group (p < 0.05). Mean values of the control and CPP-ACP groups were not significantly
different (p > 0.05).

Conclusion The amount of calcium ions dissolved in citric acid from the Novamin group was
significantly higher than the control and the CPP-ACP groups. The results from SEM showed that
these remineralizing agents provided resistance to citric acid erosion of pellicle-covered enamel.

(CU Dent J. 2015;38:1-10)