Biomimetic Effect of Nano-Hydroxyapatite in Demineralized Enamel before Orthodontic Bonding of Brackets and Attachments: Visual, Adhesion Strength, and Hardness in In Vitro Tests

Table 4

Descriptive statistics of microhardness values (VHN) in the three different conditions tested (untreated enamel, enamel after hypomineralization treatment, and enamel after hypomineralization and remineralization treatments).

Group	Enamel	Mean	St Dev	Min	Mdn	Max	Significance
1	Intact	327.43	41.22	262.65	320.00	386.90	A
2	Demineralized	238.76	33.85	198.85	229.22	297.86	B
3	Demineralized and remineralized	278.97	29.54	215.82	288.99	308.46	C