Adhesive restoration of endodontically treated premolars: influence of posts on cuspal deflection.
OBJECTIVE
To determine, by means of a non-destructive experimental procedure, the effectiveness of adhesive restorations in reducing the cuspal deflection of endodontically treated premolars, with or without root canal fiber posts.


METHODS
The cuspal deflection of ten sound, intact maxillary premolars was evaluated. A loading device induced deformation by axial force (ranging from 98 to 294 N) applied on the occlusal surface of teeth while laser sensors registered the amount of deflection. Once tested, teeth were endodontically treated and the marginal ridges were removed. The teeth were randomly divided into two groups and restored with: group 1) dual curing adhesive, flowable composite, and microhybrid composite; group 2) the same materials associated with root canal glass fiber post and composite cement. The cuspal deflection test was repeated with the same protocol after restorative procedures, allowing a direct comparison of the same samples. Statistical analysis was performed using ANOVA at a significance level of 0.05.


RESULTS
Different average cuspal deflection was detected in the two groups: composite resin with post insertion resulted in lower deformation compared with composite alone. Mean deflection ranged from 3.43 to 12.17 μm in intact teeth, from 14.42 to 26.93 μm in group 1, and from 15.35 to 20.39 μm in group 2. ANOVA found significant differences (p = 0.02).


CONCLUSIONS
Bonded composite restorations with fiber posts may be more effective than composite alone in reducing the cuspal deflection in endodontically treated premolars in which the marginal ridges have been lost.
School of Dentistry, University of Brescia, Italy.
Pier Antonio
PA
Acquaviva
Lorenzo
L
Madini
Andreas
A
Krokidis
Massimo
M
Gagliani
Francesco
F
Mangani
Antonio
A
Cerutti
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001641:Bicuspid; D003188:Composite Resins; D001840:Dental Bonding; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D005898:Glass; D006801:Humans; D008422:Materials Testing; D011176:Post and Core Technique; D019228:Tooth Crown / Q000502:physiology; D019553:Tooth, Nonvital; D055815:Young Adult
D003188:Composite Resins; C009753:fiberglass