Intraoral strain gauge measurements on complete dentures: a methodological study.

This paper discusses the advantages and the limitations of strain gauge clinical research in prosthodontics. It also demonstrates the possibility of long term studies by explaining a methodological study that was undertaken on a group of 19 patients on two occasions a year apart. Of this group six were supplied with maxillary and mandibular complete dentures, five had maxillary complete dentures and mandibular osseointegrated fixed 10-12 unit bridges, and eight had maxillary and mandibular complete dentures at the first experimental session and osseointegrated fixed 10-12 unit bridges in the mandible at the second. It was found that during maximum biting the direction of functional strain was comparatively stable at a given point of a denture. It was evident that in experiments 12 months apart no major changes had taken place in the experimental dentures nor the denture bearing tissues. The accuracy of the strain gauges used was maintained and there were no failures due to loss of retention of the gauges. Loss of insulation and short circuiting was an occasional problem but instantly recognized if it occurred.