Table 1: Cumulative failure numbers and survival rate for two treatment methods evaluated after 6, 12, and 18 months

				Reversed- metal post		Glass fiber post		Risk difference (95% CL)		p-value
6 months		Failures		1/ 39		4 / 39		7.7% (- 5.8		0.179
		Survival		97.4%		89.7%		to 21.2)%
12 months		Failures		4 / 39		10 / 39		15.4% (- 3.9		0.069
		Survival		89.7%		74.4%		to 34.6)%
18 months		Failures		7 / 37		12 / 37		13.5% (- 6.2		0.144
		Survival		81.1%		67.6%		to 33.2)%