Push-out bond strengths of different dental cements used to cement glass fiber posts.
BACKGROUND
Since the introduction of glass fiber posts, irreversible vertical root fractures have become a rare occurrence; however, adhesive failure has become the primary failure mode.


OBJECTIVE
The purpose of this study was to evaluate the push-out bond strength of glass fiber posts cemented with different luting agents on 3 segments of the root.


METHODS
Eighty human maxillary canines with similar root lengths were randomly divided into 8 groups (n=10) according to the cement assessed (Rely X luting, Luting and Lining, Ketac Cem, Rely X ARC, Biscem, Duo-link, Rely X U100, and Variolink II). After standardized post space preparation, the root dentin was pretreated for dual-polymerizing resin cements and untreated for the other cements. The mixed luting cement paste was inserted into post spaces with a spiral file and applied to the post surface that was seated into the canal. After 7 days, the teeth were sectioned perpendicular to their long axis into 1-mm-thick sections. The push-out test was performed at a speed of 0.5 mm/min until extrusion of the post occurred. The results were evaluated by 2-way ANOVA and the all pairwise multiple comparison procedures (Tukey test) (α=.05).


RESULTS
ANOVA showed that the type of interaction between cement and root location significantly influenced the push-out strength (P<.05). The highest push-out strength results with root location were obtained with Luting and Lining (S3) (19.5 ±4.9 MPa), Ketac Cem (S2) (18.6 ±5.5 MPa), and Luting and Lining (S1) (18.0 ±7.6 MPa). The lowest mean values were recorded with Variolink II (S1) (4.6 ±4.0 MPa), Variolink II (S2) (1.6 ±1.5 MPa), and Rely X ARC (S3) (0.9 ±1.1 MPa).


CONCLUSIONS
Self-adhesive cements and glass ionomer cements showed significantly higher values compared to dual-polymerizing resin cements. In all root segments, dual-polymerizing resin cements provided significantly lower bond strength. Significant differences among root segments were found only for Duo-link cement.
Department of Prosthodontics, Dental School, University of Southern Santa Catarina, Tubarão, Santa Catarina, Brazil. jeffripe@rocketmail.com
Jefferson Ricardo
JR
Pereira
Accácio
A
Lins do Valle
Janaina Salomon
JS
Ghizoni
Fábio César
FC
Lorenzoni
Marcelo Barbosa
MB
Ramos
Marcelo Ramos
MR
Barbosa
Marcus Vinícius
MV
Dos Reis Só
D000268:Adhesiveness; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002484:Cementation / Q000379:methods; D003188:Composite Resins / Q000737:chemistry; D003481:Cuspid / Q000033:anatomy & histology; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003786:Dental Pulp Cavity / Q000033:anatomy & histology; D003804:Dentin / Q000033:anatomy & histology; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008277:Magnesium Oxide / Q000737:chemistry; D008422:Materials Testing; D011076:Polycarboxylate Cement / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011176:Post and Core Technique / Q000295:instrumentation*; D019279:Resin Cements / Q000737:chemistry; D018915:Root Canal Preparation / Q000379:methods; D013314:Stress, Mechanical; D014092:Tooth Root / Q000033:anatomy & histology; D015034:Zinc Oxide / Q000737:chemistry
C542562:BisCem cement; D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C431350:Duo-Link; D005899:Glass Ionomer Cements; D011076:Polycarboxylate Cement; D011109:Polymethacrylic Acids; C462240:RelyX ARC; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C084550:Vitremer; C009753:fiberglass; C103502:Variolink; D008277:Magnesium Oxide; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C040235:Ketac-cem; D015034:Zinc Oxide