Table 3. Incidence of alveolar osteitis in patients treated with chlorhexidine 0.12% mouthwash or placebo.

	AO	Health	Total	ARR (95% CI)	NNT (95% CI)	P value
Chlorhexidine	10	362	372	4.57%	21.88	0.006*
Placebo	27	345	372	(1.5 – 7.7)	(13.0 – 69.3)
Total	37	437	744

AO: Alveolar Osteitis; ARR: Absolute Risk Reduction; NNT: Number Needed to Treat; CI: Confidence interval;

^* p<0.05; power=0.822 (Fisher's exact test)