Effect of Lactic Acid Etching on Bonding Effectiveness of Orthodontic Bracket after Water Storage

Table 1

Strength of acids and their pHs*.

Etchant	pKa1	pKa2	pKa3	pH
37% phosphoric acid	2.12	7.21	12.67	0.16
10% lactic acid	3.86	—	—	1.55
20% lactic acid	3.86	—	—	1.40
30% lactic acid	3.86	—	—	1.20
50% lactic acid	3.86	—	—	1.07

∗Power of hydrogen.