Comparison of resin-bonded prosthesis groove parallelism with the use of four tooth preparation methods.
BACKGROUND
A precise preparation is required to develop resistance form resulting in mechanical stability of the framework for resin-bonded prostheses (RBPs).


OBJECTIVE
The effects of 4 methods of tooth preparation (freehand, guiding pin, extraoral parallelometer, and intraoral parallelometer) on the deviation of proximal grooves from a preestablished path of insertion (guide planes) were investigated under clinical conditions.


METHODS
Tooth preparation of proximal grooves was performed by 32 dentists on resin substitutes of posterior segments intraorally with a single test patient. A Latin-square randomized cross-over design was selected as the experimental design.


RESULTS
The significant least angular deviation of proximal grooves from path of insertion was achieved with an intraoral parallelometer (mean +/- SD 3.15 +/- 1.67 degrees). Compared with freehand tooth preparations (4.37 +/- 2. 11 degrees), neither use of a guiding pin (4.10 +/- 1.62 degrees) nor an extraoral parallelometer (5.06 +/- 2.33 degrees) improved the results.


CONCLUSIONS
Divergence of guiding grooves from path of insertion was reduced with the use of an intra-oral parallelometer. This should improve mechanical stability of posterior RBPs.
Moschèn
I
I
School of Medicine, University of Innsbruck, Innsbruck, Austria. ivano.moschen@uibk.ac.at
Berger
P
P
Falk
M
M
Hörl
R
R
Hörle
M
M
Gausch
K
K
D000180:Acrylic Resins; D000328:Adult; D000704:Analysis of Variance; D018592:Cross-Over Studies; D003779:Denture Design / Q000295:instrumentation / Q000379:methods / Q000592:standards; D016379:Denture, Partial, Fixed, Resin-Bonded / Q000592:standards* / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008334:Mandible; D008437:Maxilla; D003765:Models, Dental; D011897:Random Allocation; D019231:Tooth Preparation, Prosthodontic / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data
D000180:Acrylic Resins