الفهرس 
Introduction…Only 14 pages are availabe for public view
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Abstract
The glass fiber reinforced post has become more popular and is well accepted for the restoration of endodontically treated teeth because its modulus of elasticity is similar to dentin.
Taking into consideration, the most frequent cause of failure of bonded glass fiber posts is debonding, so the requirement is to achieve a chemical as well as micromechanical adhesion to improve the bonding between the adhesive resin cements and the root canal dentin as well as with the resin cements and the composite resin matrix of glass fiber posts. Surface treatments for glass fiber posts and root canal dentin are commonly recommended to improve this bonding such as silanization, silica coating, air borne abrasion, and chemical etching for fiber posts, and the use of different irrigations for root canal dentin.
This study was performed to evaluate the effect of different surface treatments of glass fiber posts, pretreatment of root canal dentin and the use of two different adhesive resin cements techniques on the push out bond strength.
This in vitro study used sixty extracted human teeth. The selected teeth were sound, caries-free and crack free maxillary central incisors. Teeth average root length 14 ± 1 mm were selected, while shorter teeth were discarded, so that this length was chosen to accommodate 3-4 mm of gutta-percha while providing 10 mm for the glass fiber post.
Root canal treatment was done for all the samples by the same operator for the purpose of standardization. All the root canals were irrigated with saline solution during canal preparation to avoid any effect on bonding procedure. The used endodontic sealer was eugenol free type because eugenol containing root canal sealer might inhibit the polymerization of the resin based luting agent.
For gutta-percha removal, Peso- reamers size 1#, 2#, and 3# were used respectively to depth of 10 mm inside the prepared root canal. A rubber stopper to standardize the post length was attached to the peso-reamers, leaving 3-4 mm of gutta-percha apically.
The post space was prepared under copious water cooling using the specific drill assigned by the manufacturer for the post used. Rubber stopper was placed on the drill shaft at a length of 10 mm from cement-enamel junction.
The teeth were randomly divided into two equal groups after root canal treatment: group I The root canal dentin undergoing pretreatment by EDTA irrigation of the prepared post space for 1 min, then rinsed thoroughly by water (With EDTA group). group II the root canal dentin undergoing no treatment (Without EDTA group).
Then each group of the teeth was divided according to surface treatment of the post 3 subgroups (n=10) as follows: Subgroup A (Non fiber post treatment), Subgroup B (Silane coupling agent treatment), and Subgroup C (Silica coating treatment). The fiber posts were luted with two adhesive techniques; the total-etch and self-adhesive resin cement.
Ten disks 2mm in thickness of each group were prepared for the push-out test by a low speed diamond disc under copious water coolant.
Results:
1- There was no statistically significant difference between the different surface treatments of the fiber post with conjunction with other variables or with regardless of other variables.
2- There was no statistically significant difference between with and without EDTA irrigants on the bond strength with conjunction with other variables or with regardless of other variables.
3- Total etch resin cement showed statistically significantly higher mean bond strength than self-adhesive resin cement.
4- Without EDTA irrigant, there was no statistically significant difference between the two cements. While with EDTA irrigant; total etch resin cement showed statistically significantly higher mean bond strength than self-adhesive resin cement with Silane treatment.
5- Without EDTA as well as with EDTA irrigants; total etch resin cement showed statistically significantly higher mean bond strength than self-adhesive resin cement with silica coating treatment.
Conclusions:
Within the limitations of this study, the following conclusions may be drawn:
1- The use of Silane coupling agent and Silica coating did not provide increased bond strength between the fiber posts and the resin cement, so this saves time in the clinical situation.
2- Rinsing the post space preparation with EDTA does not improve the bond strength of the fiber post to root canal dentin.
3- The Total etch resin cement gives higher bond strength more than the self-adhesive resin cement with the fiber post.
4- The use of Total etch resin cement improves the bond strength of the silanated posts more than self-adhesive resin cement with EDTA irrigant.
5- The use of Total etch resin cement improves the bond strength of Silica coated posts more than self-adhesive resin cement with EDTA and without EDTA irrigant.
Recommendation:
1- During cementation of the fiber post, it is not preferred to use Silane coupling agent, Silica coating and, EDTA irrigants as they don’t improve the bond strength.
2- It is recommended to use the Total etch resin cement when luting the fiber posts as it provide better bond strength more than self-adhesive resin cement.