Effect of the length of glass fiber posts on the fracture resistance of restored maxillary central incisors.
OBJECTIVE
To evaluate the influence of post length insertion on the fracture resistance of directly restored endodontically treated teeth.


METHODS
30 maxillary central incisors were restored with glass fiber posts and composite cores to produce groups with post lengths of (1) 5 mm, (2) 7 mm, and (3) 9 m. Specimens were loaded at 130 degrees (Instron). Fracture strengths were analyzed with the Kolmogorov-Smirnov Test to verify the normality of the data distribution and with ANOVA and Tukey's post hoc test at P < 0.05. Fracture patterns (restorable or unrestorable) were analyzed (Pearson's Chi-square test).


RESULTS
The average fracture resistance was: Group 1 = 366.4 N, Group 2 = 507.4 N and Group 3 = 509.9 N. No significant difference was found among the three groups for fracture resistance or for failure mode. The insertion length did not influence the fracture pattern; more restorable fractures were detected.
Department of Fixed Prosthodontics and Restorative Dentistry, Tuscany School of Dental Medicine, University of Florence and Siena, Italy. borelli.bruna@unisi.it
Bruna
B
Borelli
Roberto
R
Sorrentino
Fernando
F
Zarone
Marco
M
Ferrari
D000134:Acid Etching, Dental / Q000379:methods; D003188:Composite Resins / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003786:Dental Pulp Cavity / Q000473:pathology; D003799:Dental Stress Analysis / Q000295:instrumentation; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D006801:Humans; D006813:Humidity; D007180:Incisor / Q000473:pathology / Q000503:physiopathology*; D008422:Materials Testing; D011176:Post and Core Technique / Q000295:instrumentation*; D019279:Resin Cements / Q000737:chemistry; D018915:Root Canal Preparation / Q000379:methods; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D014082:Tooth Fractures / Q000503:physiopathology*; D019553:Tooth, Nonvital / Q000473:pathology / Q000628:therapy*
D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C474035:Filtek Supreme; C483701:Rely X Unicem; D019279:Resin Cements; C009753:fiberglass