Objectives: The aim of this in vitro investigation was to evaluate the shear strength of RelyX™ Fiber Post (RXFP, 3M ESPE), a new glass fiber reinforced composite post, in comparison to other fiberposts.
Materials and methods: RXFP and six other fiber reinforced composite posts of various brands were submitted to a shear strength test. Posts tested were FRC Postec® Plus (FRCP, ivoclar vivadent), Komet ER Dentin Post (ERDP, Brasseler), Fibiocore (FIBP, anthogyr), Radix Fiber Post (RDFP, Dentsply), FibreKor® (FKOR, Jeneric) and DT Light Post® (DTLP, RTD). Posts were fixed in a metal block and loaded at an angle of 135 degrees relative to the long axis of the post using a universal testing machine (Zwick Z010, crosshead speed of 1mm/min).
In order to investigate whether the mechanical properties of RXFP change due to thermal stressing shear strength was determined after thermo-cycling (5.000 cycles and 10.000 cycles 5 °C / 55 °C, dwell time: 30 s, change time: 8 s).
Results: The following tables summarize the shear strength of the fiberposts tested. Thermocycling did not change shear strength of RXFP.
|
|
RXFP (Size 3) |
FRCP (Size 3) |
ERDP (Size 110) |
FIBP (Size FBC 4) |
RDFP (Size 4) |
FKOR (Size 2) |
DTLP (Size 3) |
|
Shear strength [GPa] |
1,4 ± 0,1 |
1,2 ± 0,3 |
1,2 ± 0,1 |
1,3 ± 0,2 |
1,3 ± 0,1 |
1,3 ± 0,1 |
1,5 ± 0,1 |
|
Thermocyling |
RXFP (5.000 TC) |
RXFP (10.000 TC) |
|
Shear strength [GPa] |
1,4 ± 0,1 |
1,4 ± 0,1 |
Conclusions: RXFP showed shear strength comparable to other fiberposts. Mechanical properties of RXFP are not prone to thermal stressing.