Effects of bonded composites vs. amalgam on resistance to cuspal deflection for endodontically-treated premolar teeth.
OBJECTIVE
To determine, by means of a non-destructive experimental procedure, the extent to which tooth cusps are weakened by endodontic procedures and the effectiveness of adhesive bonding restoration in reducing cuspal deflection as a function of different restorative procedures.


METHODS
A mechanically controlled loading device induced cuspal deflection by axial force (range 98-294 N) on an occlusal surface while LTS laser twin sensors registered the amount of deflection. Cusp deflection values, in microns, were recorded for each tooth. Thirty sound maxillary premolars teeth were sequentially evaluated in the following conditions: A) intact tooth; B) completion of endodontic and restorative procedures. Teeth were randomly divided into five groups and restored respectively with: A) amalgam (Dispersalloy); B) Spectrum TPH; C) Surefil; D) Esthet-X; E) Esthet-X + Dyract Flow.


RESULTS
The average loading force needed to induce 1 microm cusp deflection was evaluated, for all groups, in intact teeth (range 49.52-58.76 N/microm) and in restored teeth (range 8.56 - 47.05 N/microm). Statistical analysis (ANOVA for repeated measures) has been performed. Mean structural recovery values after restorative treatment were 17% with amalgam, 60% with Spectrum TPH, 59% with SureFil, 54% with Esthet-X, and 99% with Esthet-X/Dyract.
Cerutti
Antonio
A
Department of Restorative Dentistry, School of Dentistry, University of Brescia, P. le Spedali Civili 1, 25123 Brescia, Italy. cerant@tin.it
Flocchini
Piera
P
Madini
Lorenzo
L
Mangani
Francesco
F
Putignano
Angelo
A
Docchio
Franco
F
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001641:Bicuspid / Q000503:physiopathology*; D001732:Bite Force; D020770:Compomers / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry*; D001840:Dental Bonding; D004548:Elasticity; D006801:Humans; D012390:Root Canal Therapy; D019228:Tooth Crown / Q000503:physiopathology*; D019553:Tooth, Nonvital / Q000503:physiopathology* / Q000628:therapy
D020770:Compomers; D003188:Composite Resins; D003722:Dental Alloys; C088486:Dyract; C466112:Esthet-X; C420128:Spectrum composite resin; C403464:SureFil packable composite; C033470:Dispersalloy; D003723:Dental Amalgam