Table 2.

Number of bacteria (colony forming units (CFU)/biofilm), expressed as mean and standard deviations (SDs) of S. oralis, A. naeslundii, V. parvula, F. nucleatum, A. actinomycetemcomitans, and P. gingivalis grown as multispecies biofilm at the different times of incubation, measured by quantitative real-time polymerase chain reaction (qPCR) (n = 9 for each incubation time and material). Titanium discs (TiDs) were used as a negative control as compared with TiDs coated with non-doped nanoparticles (Un-NPs), or doped with calcium (Ca-NPs), zinc (Zn-NPs), and doxycycline (Dox-NPs).

Bacterial Species	Time of Incubation	Number of Bacteria (CFU/Biofilm, Expressed as Mean (SD))
		Control	Un-NPs	Ca-NPs	Zn-NPs	Do × -NPs
So	12 h	4.36 × 107	7.99 × 107	8.80 × 107	1.05 × 108	2.03 × 104
		(1.12 × 107)	(1.89 × 107) *	(1.94 × 107) *	(3.28 × 107) *	(1.30 × 104) *
	24 h	4.92 × 107	1.08 × 108	1.09 × 108	7.99 × 107	7.75 × 105
		(3.92 × 107)	(6.78 × 107)	(7.19 × 107)	(4.58 × 107)	(1.19 × 106) *
	48 h	4.02 × 107	4.45 × 107	5.45 × 107	5.19 × 107	6.63 × 104
		(2.17 × 107)	(4.65 × 107)	(2.34 × 107)	(3.07 × 107)	(6.83 × 104) *
	72 h	7.42 × 107	1.33 × 108	9.88 × 107	1.37 × 108	1.97 × 105
		(3.19 × 107)	(5.75 × 107)	(3.59 × 107)	(5.35 × 107) *	(2.76 × 105) *
An	12 h	3.47 × 105	5.11 × 105	4.98 × 105	4.68 × 105	3.72 × 104
		(2.28 × 105)	(3.62 × 105)	(2.35 × 105)	(2.41 × 105)	(2.17 × 104) *
	24 h	9.68 × 106	1.10 × 107	1.30 × 107	7.21 × 106	4.64 × 104
		(8.94 × 106)	(1.06 × 107)	(1.49 × 107)	(4.50 × 106)	(9.98 × 103) *
	48 h	4.14 × 106	3.90 × 106	4.37 × 106	4.34 × 106	5.10 × 104
		(2.47 × 106)	(2.90 × 106)	(3.14 × 106)	(2.92 × 106)	(2.41 × 104) *
	72 h	7.72 × 106	8.87 × 106	7.74 × 106	9.71 × 106	5.06 × 104
		(4.92 × 106)	(5.90 × 106)	(4.73 × 106)	(3.82 × 106)	(9.75 × 103) *
Vp	12 h	3.98 × 106	4.67 × 106	5.79 × 106	1.28 × 107	9.72 × 103
		(5.02 × 106)	(5.14 × 106)	(6.80 × 106)	(2.09 × 107)	(5.71 × 103) *
	24 h	2.71 × 108	2.93 × 108	3.87 × 108	2.87 × 108	3.15 × 105
		(2.49 × 108)	(2.43 × 108)	(3.30 × 108)	(3.15 × 108)	(4.41 × 105) *
	48 h	3.39 × 108	3.03 × 108	3.68 × 108	3.06 × 108	8.82 × 105
		(2.88 × 108)	(4.47 × 108)	(2.19 × 108)	(2.59 × 108)	(1.17 × 106) *
	72 h	8.41 × 108	9.66 × 108	5.55 × 108	9.60 × 108	6.87 × 105
		(6.59 × 108)	8.82 × 108)	(2.75 × 108)	(6.83 × 108)	(7.52 × 105) *
Fn	12 h	2.56 × 106	5.93 × 106	4.35 × 106	8.63 × 106	4.95 × 105
		(1.40 × 106)	(4.98 × 106)	(2.58 × 106)	(7.15 × 106)	(2.71 × 105) *
	24 h	6.41 × 106	1.34 × 107	1.02 × 107	1.23 × 107	2.17 × 105
		(3.73 × 106)	(1.16 × 107)	(3.18 × 106)	(1.03 × 107)	(1.34 × 105) *
	48 h	2.20 × 107	2.45 × 107	2.77 × 107	2.65 × 107	2.81 × 105
		(1.85 × 107)	(3.03 × 107)	(1.86 × 107)	(2.33 × 107)	(2.95 × 105)*
	72 h	3.95 × 107	4.30 × 107	3.19 × 107	5.20 × 107	2.78 × 105
		(3.08 × 107)	(3.32 × 107)	(7.63 × 106)	(3.07 × 107)	(1.23 × 105) *
Aa	12 h	1.18 × 107	2.39 × 107	1.93 × 107	2.51 × 107	9.16 × 105
		(1.70 × 107)	(3.41 × 107)	(2.69 × 107)	(3.75 × 107)	(1.32 × 106)
	24 h	2.48 × 106	5.42 × 106	5.04 × 106	5.76 × 106	1.25 × 105
		(1.78 × 106)	(3.61 × 106)	(3.52 × 106)	(4.63 × 106)	(7.29 × 104)*
	48 h	3.64 × 105	5.88 × 105	7.16 × 105	5.60 × 105	1.10 × 105
		(2.46 × 105)	(3.87 × 105)	(6.27 × 105)	(3.63 × 105)	(6.76 × 104) *
	72 h	8.70 × 106	8.84 × 106	3.97 × 106	5.67 × 106	9.82 × 104
		(1.10 × 107)	(1.70 × 107)	(3.42 × 106)	(4.60 × 106)	(3.88 × 104) *
Pg	12 h	5.60 × 105	1.26 × 106	1.17 × 106	1.52 × 106	3.30 × 105
		(4.07 × 105)	(4.74 × 105) *	(6.64 × 105)	(5.10 × 105) *	(1.49 × 105)
	24 h	8.22 × 105	2.13 × 106	2.21 × 106	2.10 × 106	2.47 × 105
		(9.92 × 105)	(1.84 × 106)	(2.17 × 106)	(2.05 × 106)	(2.19 × 105)
	48 h	1.81 × 106	2.32 × 106	2.65 × 106	2.92 × 106	2.71 × 105
		(2.42 × 106)	(3.18 × 106)	(4.17 × 106)	(5.33 × 106)	(2.77 × 105)
	72 h	2.18 × 107	5.30 × 107	5.11 × 107	9.03 × 107	5.75 × 105
		(2.78 × 107)	(7.75 × 107)	(7.48 × 107)	(1.34 × 108)	(8.43 × 105) *

* Statistically significant differences as compared with negative control titanium discs (p < 0.01). No statistical differences were found among Un-NPs, Ca-NPs, and Zn-NPs. Numbers in parentheses are standard deviation values. So, Streptococcus oralis; An, Actinomyces naeslundii; Vp, Veillonela parvula; Fn, Fusobacterium nucleatum; Pg, Porphyromonas gingivalis; Aa, Aggregatibacter actinomycetemcomitans.