Fracture Strength and Stress Distribution in Premolars Restored with Cast Post-and-Cores or Glass-Fiber Posts Considering the Influence of Ferule

Table 2

The mean fracture strength (N), standard deviation (±SD), and failure mode for each experimental condition.

Groups	Fracture strength (N)	Failure mode distribution
		Type 1	Type 2	Type 3	Type 4	Type 5	Repairable	Irreparable
FPC - F	1,031.93; (383.10)	-	5	5	-	-	5	5
FPC - NF	620.15; (241.82)	2	5	1	1	1	7	3
CPC - F	1,266.57; (352.76)	-	3	7	-	-	3	7
CPC - NF	809.72; (206.11)	-	6	3	-	1	6	4
Main effect: Ferule,; Post type,
Interaction effect: Ferule x post type,

FPC, fiber post relined with composite resin; CPC, cast post-and-core. F – Ferule; NF – no ferule. Uppercase letters represent the significance for the factor “ferule” within the same post material; lowercase letters represent significance for the factor “post material” within the same ferule condition.