The effect of slot preparation length on the transverse strength of slot-retained restorations.
An in vitro study was conducted (1) to compare fracture strength of amalgam restorations retained with retentive slots of different lengths when stressed with a transverse force, (2) to determine if beveling the slot preparation resulted in an increase in fracture resistance to a transverse force, and (3) to evaluate the incidence of unrestorable tooth fracture as it relates to slot preparation length. Six groups of 10 specimens were prepared with slots of increasing length, with each specimen receiving four slots of equal length. Slot preparations in group 6 were beveled. Results showed that shorter slot preparations provided statistically equal amounts of resistance to a transverse force as did the longer preparations. Beveling the slot preparation did not significantly increase fracture strength. Specimens restored with longer slot preparations failed unrestorably more often than restorations retained with shorter slot preparations.
McMaster
D R
DR
Comprehensive Dentistry Department, Naval Dental School, National Naval Dental Center, Bethesda, Md.
House
R C
RC
Anderson
M H
MH
Pelleu
G B
GB
D003723:Dental Amalgam / Q000737:chemistry; D003737:Dental Cavity Preparation / Q000379:methods*; D003743:Dental Enamel; D003793:Dental Restoration, Permanent; D003799:Dental Stress Analysis; D003804:Dentin; D006801:Humans; D015994:Incidence; D013314:Stress, Mechanical; D013499:Surface Properties; D014082:Tooth Fractures / Q000209:etiology
D003723:Dental Amalgam