Development of a new bite force measurement device

The computer aided design (CAD) of all-ceramic bridges is usually carried out by subjective considerations based on experiences of the designer. The individual situation in the patients' oral cavities are normally not regarded. Especially the individual development of local forces where bridges have to be placed were usually not measured. So it remains always a lot of uncertainty if the framework will be rigid enough.

The aim of the study was to develop a device for individual measurements of bite forces in a circumscribed area to use the data for dimensioning all-ceramic bridges.

Methods:

Two different sensors ( a piezoelectric transducer and a strain gauge) were used. For each of them a special holder for the use in the mouth was constructed. For processing the data also a new signal processing device was developed. Both test setups were calibrated by repeated measures in a Universal Testing Device (Zwick). Afterwards a clinical trial was performed: Three patient groups (Total N = 42) were build: Students with sound teeth (n = 26), patients with partial dentures (n=8) and patients with full dentures (n=8). Biting forces of each patient were measured at three different days with two measurements for each device in three different areas: anterior teeth, premolars and molars.

Results:

Bite forces of the patients are very individual and depend also on the remaining teeth. The students without any tooth loss revealed the highest forces up to 1081 N. Patients with partial dentures showed significantly lower bite forces of 200 N (mean value) and full denture patients revealed the lowest forces of only 56.5 N.

Conclusion:

The results revealed that both measuring devices produced accurate and repeatable values.The high variability of individual bite forces suggests a case-depending measurement for higher safety in designing frameworks for all ceramic bridges.