Background

Previous bench-top studies examined the details of the mechanical environment of rigidly fixed occluding teeth. It was demonstrated that during each chomp, contacting molar teeth experience in-occlusal-plane forces (Flateral) that are highly transient in magnitude and direction.

Objectives

The objectives of this study are to identify Flateral behaviours that are attributable to the presence of a visco-elastic periodontal ligament (PDL) analogue, and to assess the necessity of incorporating it into future studies.

Methods

A weighted maxillary molar denture tooth was lowered onto, and raised from, a matching mandibular molar 10 times. The latter was supported by a load cell that continuously measured Flateral. For statistical purposes, the test was repeated with 21 (n = 21) different occlusal relationships obtained with 0.05 mm incremental shifts of the lower assembly.

Results

Overall, the results are similar to those of rigid attachment but the details of the Flateral profiles are very different.

Conclusion

The PDL plays a major role in the mechanical environment of occlusion, suggesting that, in general (not necessarily always), it should be integrated into studies of occlusion.