Efficient immobilisation protocols are the result of perfect matching of factors depending on the enzyme, the process and the support for immobilisation. Physical-chemical phenomena, such as partition, solvation and diffusion, strongly affect the efficiency of the biocatalyst in each specific reaction system. Therefore, tailored solutions must be developed for each specific process of interest. Indeed, direct investigation of what occurs at the molecular level in a reaction catalysed by an immobilised enzyme is a quite formidable task and observed differences in the performance of immobilised biocatalysts must be interpreted very carefully. In any study dealing with enzyme immobilisation the prerequisite is the rigorous planning and reporting of experiments, being aware of the complexity of these multi-phase systems.

The influence of occlusal conditions on stomatognathic function can be assessed by electromyography. Electromyographic activity of left and right temporal and masseter muscles was recorded in 30 young healthy adults with a normal occlusion during: (1) a 3-s maximum voluntary clench on cotton rolls positioned on the posterior teeth (standardization recording); (2) a 3-s maximum voluntary clench in intercuspal position; and (3) a 3-s alternate 'maximum' voluntary contraction and relaxation with a 1 Hz frequency. All potentials were standardized as a percentage of the maximum potential of test 1. Waveforms of paired muscles were compared by computing a percentage overlapping coefficient (ratio between each 50-ms overlapped areas and the total areas, up to 100% for symmetric muscles). Waveforms were also analysed for a laterodeviating effect on the mandible given by unbalanced muscular couples, and a torque coefficient (up to 100% for a significant laterodeviating couple on the mandible) was computed. In all subjects, both tests were performed with symmetric muscular patterns (more than 88%) and with negligible laterodeviating couples on the mandible (lower than 10%). The two coefficients allow an assessment of muscular asymmetry during static and dynamic clenching tests, and, together with the standardization of the potentials, could be a useful tool to detect functionally altered occlusal conditions, i.e. conditions where an apparent good morphological situation is not related to a correct neuromuscular status.

summary  The assessment of bite forces on healthy single tooth appears essential for a correct quantification of the actual impact of single implant oral rehabilitations. In the present study, a new single tooth strain‐gauge bite transducer was used in 52 healthy young adults (36 men, 16 women) with a complete permanent dentition. The influences of tooth position along the dental arch, of side, and of sex, on maximum bite force were assessed by an anova. No significant left–right differences were found. On average, in both sexes the lowest bite force was recorded on the incisors (40–48% of maximum single tooth bite force), the largest force was recorded on the first molar. Bite forces were larger in men than in women (P < 0·002), and increased monotonically along the arch until the first or second permanent molar (P < 0·0001). The present data can be used as reference values for the comparison of dental forces in patients.

Electromyographic activity of anterior temporal and masseter muscles was measured in 92 young healthy men and women with sound dentitions during rest position, contact in centric occlusion and clench. Male and female mean potentials were similar except in clench, where males had higher electromyographic levels. Mean pooled electromyographic potentials were 1.9 microV (TA) and 1.4 microV (MM) during rest position, 6.5 microV (TA) and 2.8 microV (MM) during contact in centric occlusion. Mean maximum voluntary clench potentials were 181.9 microV (TA) and 216.2 microV (MM) in men, 161.7 microV (TA) and 156.8 microV (MM) in women. Examined muscles were more asymmetric at low electromyographic activity (rest and centric occlusion) with the temporal muscle less asymmetrical than the masseter. In females temporal muscle activity tended to dominate at every contraction level, while in males masseter activity was stronger in clench, and temporal activity in centric occlusion and in rest position.

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