Int Poster J Dent Oral Med 2005, Vol 7 No 02, Poster 272
The Reliability of a New Device for Measuring the Proximal Contact Strength
Dr. Bas A. C. Loomans, School of Dental Sciences, University Medical Centre Nijmegen, the Netherlands
Dr. Diana Wolff, Clinic for Conservative Dentistry, School of Dental Medicine, University of Heidelberg
Dr. Daniela Jörß, Clinic for Conservative Dentistry, School of Dental Medicine, University of Heidelberg
Dr. Niek J. M. Opdam, School of Dental Sciences, University Medical Centre Nijmegen, the Netherlands
Dr. Ewald M. Bronkhorst, School of Dental Sciences, University Medical Centre Nijmegen, the Netherlands
Dr. Thomas Pioch, Clinic for Conservative Dentistry, School of Dental Medicine, University of Heidelberg
Priv.-Doz. Dr. Christof E. Dörfer, Clinic for Conservative Dentistry, School of Dental Medicine, University of Heidelberg
IADR Göteborg, Schweden
When different investigators use a measuring device within the scope of a study, particularly in multicenter studies, their calibration is essential for the reliability of the results.
The purpose of this study was to test the inter- and intra-examiner reliability of a recently developed instrument for measuring the proximal contact strength (Tooth Pressure Meter: TPM, based on the publication of Dörfer et al. 2000).
Material and Methods
Ten healthy adults with complete dentition and no signs of periodontitis or caries volunteered in this study. Inclusion criteria were continuous dental arches including the second molars, full eruption and occlusion of teeth, contralateral teeth and antagonists, no orthodontic banding or intra-oral prosthesis.
Measuring device: Tooth Pressure Meter (TPM)
To measure proximal contact strength, frictional forces at removal of a straight 0.05 mm thick metal matrix band inserted between adjacent teeth were recorded. Custom-written software in Excel (MS Office) was used for data acquisition and for the construction of diagrams relating force (N) to seconds (s). Proximal contact strength was quantified as the maximum frictional force. Visible irregularities of the graph, e.g. due to deformations of the metal matrix band during positioning, precluded the inclusion of the data for analysis and led to a repetition of the experiment.
|Fig. 1: Schematical diagram TPM, mode of functioning.
|Fig. 2: Lateral view (left), frontal view (right).
All contacts between the canine and the second molar were measured from mesial to distal either in the upper right and lower left or in the upper left and lower right quadrant. The order was randomly selected. Without any prior calibration, two investigators (I1 and I2) measured all interproximal contacts in alternate order two times (T1 and T2) each. The sequence of the investigators was randomly given as well.
|Fig. 3: TPM before measurement between the lower right second premolar and first molar.
||Fig. 4: Removal of metal matrix band of the TPM inserted between adjacent teeth.
Procedure for each interproximal contact:
- A minimum of 3 measurements
- All measurements in a maximum range of 0,5 N
- Avarage of three measurements was used for further analysis
The TPM diagram
|Axis of abscissae:
|Axis of ordinates:
||Sample [Nr], (500 samples, 1 sample/ 20 ms)
||Measurement of proximal contact strength [N]
||Reference measurement [N]
|Fig. 5: TPM diagram relating force (N) to seconds (s).
Intra-examiner reliability: Standard deviations of single measurements between the first and the second measurement separately for both investigators were taken.
Inter-examiner reliability: Standard deviations of single measurements between the two examiners at the first and second measurement were taken.
The Wilcoxon test for paired samples was used for data-analysis.
|For I1: 0.33 ± 0.28 N;
||On T1: 0.47 ± 0.42 N;
|For I2: 0.36 ± 0.31 N (p > 0.05)
||On T2: 0.36 ± 0.35 N (p = 0.04).
It is concluded that the TPM produced reliable results. The reduction of the inter-examiner reliability between T1 and T2 indicates, that calibration is necessary to generate more reproducible results.
This Poster was submitted by Dr. Diana Wolff.
Dr. Diana Wolff
Abteilung für Zahnerhaltung
Mund-, Zahn- und Kieferklinik
Im Neuenheimer Feld 400