International Journal of Dentistry

Research Article

Effect of pH of In-Office Bleaching Gels and Timing of Fluoride Gel Application on Microhardness and Surface Morphology of Enamel

Table 3

Descriptive values of enamel microhardness in study groups at baseline, 1^th (T1), 7^th (T7), and 14^th (T14) day after bleaching and topical fluoride application (n = 10).


Time	Groups	Mean ± SD	Min.	Max.	Median

T0	G1	375.50 ± 23.32	333	412	30
	G2	386.40 ± 23.97	352	416	10
	G3	377.10 ± 19.44	352	400	15
	G4	380.20 ± 21.46	345	406	20
	G5	380.30 ± 24.45	345	413	20
	G6	377.90 ± 15.07	352	406	30
	G7	379.40 ± 20.41	343	406	30
	G8	383.30 ± 21.13	352	411	30

T1	G1	380.30 ± 18.76	406.00	352.00	30
	G2	388.10 ± 18.52	427.00	363.00	10
	G3	364.60 ± 25.69	400.00	317.00	25
	G4	353.30 ± 70.04	434.00	209.00	15
	G5	424.70 ± 52.61	491.00	337.00	25
	G6	361.70 ± 62.92	465.00	308.00	10
	G7	397.00 ± 38.11	457.00	337.00	10
	G8	371.90 ± 50.31	442.00	291.00	20

T7	G1	382.80 ± 21.78	413.00	352.00	10
	G2	383.00 ± 22.55	406.00	347.00	15
	G3	323.80 ± 48.40	381.00	227.00	10
	G4	347.80 ± 38.54	400.00	280.00	10
	G5	418.40 ± 34.98	473.00	352.00	25
	G6	391.90 ± 26.05	427.00	337.00	20
	G7	396.10 ± 52.87	491.00	308.00	20
	G8	401.80 ± 47.14	465.00	308.00	10

T14	G1	390.00 ± 28.46	442.00	347.00	20
	G2	405.80 ± 22.11	434.00	375.00	20
	G3	320.70 ± 35.91	375.00	272.00	20
	G4	332.30 ± 77.04	427.00	245.00	10
	G5	482.30 ± 47.92	548.00	434.00	10
	G6	416.40 ± 56.69	482.00	337.00	10
	G7	420.10 ± 47.97	491.00	352.00	15
	G8	411.40 ± 25.62	449.00	363.00	30

Abbreviations: T0, T1, T7, and T14 are enamel microhardness values at baseline, first, second, and third session of treatment. Negative control specimen (unbleached) (G1); Positive control specimen (2% neutral sodium fluoride) (2% NaF) (G2); specimen bleached with Pola Office (G3); specimen bleached with Pola Office+ (G4); specimen bleached with Pola Office and treated with 2% NaF for 4 min (G5); specimen treated with 2% NaF 24 hr before bleaching process with Pola Office (G6); specimen bleached with Pola Office+ and treated with 2% NaF for 4 min (G7); specimen treated with 2% NaF 24 hr before bleaching process with Pola Office+ (G8).