Long-Term Fluoride Exchanges at Restoration Surfaces and Effects on Surface Mechanical Properties

Table 2

Method overview.

Analysis undertaken	Group 1 (fluoride release/recharge)	Group 2 (mechanical properties; elastic modulus/hardness)
Specimen number per material	3	6
Storage media	Deionized water	Deionized water (3); Lactic acid pH 4 (3)
Analysis times over 18 mth aging	Bimonthly (0, 2, 4, 6, 8, 10, 12, 14, 16, and 18 mths)	24 hrs, 1 mth, 3 mths, 6 mths, 12 mths, and 18 mths
Time elapsed following 18 mth F^− recharge before recharge analysis	2 months	24 hours