Table 3. Comparison of the mean periodontal probing depth (mm) and clinical attachment level (mm) according to the treatment groups (1% ALN gel or placebo gel) over time.

Parameters		Groups	Experimental times		p-value
		Baseline	3 months	6 months
Periodontal Probing Depth (mm; mean±sd) (n=20 sites)	ALN	6.4±1.4	4.3±1.6	4.3±1.6	< 0.001 [Baseline > (3 months = 6 months)]
	Placebo	6.2±1.6	4.4±1.8	4.4±1.7	0.004 [Baseline > (3 months = 6 months)]
	p-value	0.468 (ALN = Placebo)	0.239 (ALN = Placebo)	0.127 (ALN = Placebo)
Clinical attachment level (mm; mean±sd)(n=20 sites)	ALN	6.9±1.2	4.3±1.1	3.6±0.7	< 0.001 (Baseline > 3 months > 6 months)
	Placebo	6.7±1.1	5.1±0.9	4.3±0.7	< 0.001 (Baseline > 3 months > 6 months)
	p-value	0.356 (ALN = Placebo)	0.010 (ALN = Placebo)	0.021 (ALN = Placebo)

ALN, Alendronate Sodium. sd, standard deviation. Significance probability was calculated using the Friedman test for comparison of the variables between the evaluation times and the Wilcoxon test between the treatment groups. Significant p-values are indicated in bold.