Load distribution in fixed space maintainers: a strain-gauge analysis.

PURPOSE

The purpose of this study was to compare the biomechanics of space maintainers supported by primary and permanent teeth.

METHODS

Photoelastic models of permanent and primary teeth with a single missing tooth space were cast, and band-and-loop, direct-bonded, and fiber-reinforced space maintainers were fabricated. Linear strain-gauges were bonded next to the teeth and in the middle of the missing tooth space. Strain gauge signals were quantified during 50 N and 100 N static axial load applications on the molar, maintainer, and anterior support at 10 KHz using a data acquisition device and associated computer software.

RESULTS

Regardless of the tooth being restored, strains around the molar teeth and the maintainer region were comparable between the groups under molar and maintainer loading (P>.05). Under 100 N loading on the anterior support, the highest strains were observed in the direct-bonded group (P<.01). Direct-bonded design led to higher strains than the band-and-loop design under 100 N maintainer loading, whereas the strain output of other designs were comparable.

CONCLUSION

Load distribution of band-and-loop, direct-bonded, and fiber-reinforced space maintainers seem comparable, although direct-bonded maintainers could lead to higher strain concentrations in the buccal side due to bending moments.