Entwicklung und Test einer aktiven Messelektrode für das Prepometer-Eine In-vitro-Untersuchung-
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Philipps-Universität Marburg
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Summary
The fixed partial denture is a typical part of the present standard dentistry. The technical indication is when minimally invasive methods are no longer able to successfully treat a destroyed tooth. In order to be able to place a partial denture on the tooth, it is necessary to take a preparation. The preparation always leads to a dentin-wound, which includes a high risk of damaging the pulp or the loss of sensation and vitality of the tooth. In order to prevent the negative results of a preparation, it has already been intensively discussed and well known in Germany to limit the minimum thickness of dentin to 0,7 mm for teeth with small diameter dentine tubules and 1,4 mm for teeth with wide diameter dentine tubules (Hellwig, E., Kimmel, K., Lehmann, K. M.).
Various studies (Gente 1987, Feige 1989, Wenz 1990, Gente und Wenz 1991, Gente 1992, Becker-Detert 1993, Gente 1995, Bruchmann 2003, Gente 2007) prior to the development of the Prepometer® and an in-vivo dissertation of Bruchmann (2003) prove that the best way to keep the limit of the thickness of dentine is the measurement by electrical resistance.
The selling company of the Prepometer® gave the information of reticence of the dentists in private practice by using the Prepometer®. The named reticence could be explained by the measuring behavior of the measuring electrode. While moving the electrode toward the dentine surface, the measurement made by the Prepometer® is smaller than the actual measurement, made when the electrode has contact to the dentine surface. This measuring behavior could lead to problems when being used by inexperienced dentists. This fact leads to the necessity to develop a new electrode in which measurements are ordered from high to low while approaching to the dentine surface.
During this dissertation a new probe was developed by using two electrodes which are arranged concentrically and isolated from each other. The outside electrode is an active electrode and the inner one is the measuring electrode. An improvement of the electric circuit of the active electrode allowed the discontinuation of a plastic cuff which was indispensable to make a measurement possible.
During the in-vitro study with fresh extracted teeth and a specific experimental apparatus, it was possible to compare the measuring behavior of the old and new electrodes while approaching the dentine surface. The result was a better measuring behavior. The new electrode shows infinite measurements of the electric resistance until the first current flow. Now the measurements fall to the real measurement when the electrode has full contact to the dentine surface with an average difference of 8 kOhm. This difference is negligible.
During the comparison of the measurement behavior of the old and new electrode by measuring the thickness of dentine, a disadvantage of the new electrode could not be found.
These results lead us to the conclusion that the Prepometer® of the first generation could be exchanged by a new Prepometer® which is based on the knowledge of this study. The prerequisite are following in-vitro and in-vivo studies.
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Created: 2011Issued: 2011-09-06Updated: 2019-08-30
Faculty
Medizin
Publisher
Philipps-Universität Marburg
Language
ger
Data types
DoctoralThesis
Keywords
Abschirm- Treiber- TechnikÜberkronungPrepometerDentindickePreparationResistance measurementPrepometer
DFG-subjects
WiderstandsmessungPräparationRestaurative ZahnmedizinZahnpulpaDentin
DDC-Numbers
610
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Stein, Steffen: Entwicklung und Test einer aktiven Messelektrode für das Prepometer-Eine In-vitro-Untersuchung-. : Philipps-Universität Marburg 2011-09-06. DOI: https://doi.org/10.17192/z2011.0560.
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This item has been published with the following license: In Copyright