Effect of abutment tooth reinforcement techniques on the fracture resistance of removable partial denture master casts.
OBJECTIVE
The purpose of this study was to compare the mean loads required to fracture an isolated stone abutment tooth when various reinforcement techniques were used: (A) no reinforcement, (B) surface hardening, (C) impression trimming, (D) dowel placement, and (E) impression trimming plus dowel placement.


METHODS
Die stone premolar specimens for each group (n = 4) were loaded perpendicular to the tooth long axis in 100-g increments 25 hours after pouring the impression. Mean load to failure was determined for each group. Data were evaluated with a one-way analysis of variance (alpha = 0.05) to determine differences among groups. Paired comparisons of factor level means were made with Tukey's q-test.


RESULTS
The mean fracture load for Group E (7.6 kg) was significantly greater than Groups A (2.0 kg), B (2.1 kg), and C (3.4 kg). No significant difference was found between Groups D (6.0 kg) and E.


CONCLUSIONS
Dowel reinforcement with impression trimming at the cervical portion of the abutment tooth resulted in significantly greater fracture resistance than the control, surface model hardener, or impression trimming alone. J Prosthodont 2001;10:22-25.
Sato
Y
Y
Department of Removable Prosthodontics, Hiroshima University School of Dentistry, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan. sato@hiroshima-u.ac.jp
Takaki
N
N
Tsuga
K
K
Hosokawa
R
R
D000704:Analysis of Variance; D001641:Bicuspid; D002133:Calcium Sulfate / Q000737:chemistry; D000044:Dental Abutments; D003734:Dental Casting Investment / Q000737:chemistry; D003735:Dental Casting Technique / Q000295:instrumentation; D003832:Denture, Partial, Removable; D004868:Equipment Failure; D006244:Hardness; D006801:Humans; D003765:Models, Dental; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties
D003734:Dental Casting Investment; D002133:Calcium Sulfate