Method: Twenty healthy subjects (ten female and ten male, mean age: 24.1±1.2 years) chewed standardized silicone particles performing 15 masticatory cycles. Four experimental conditions were investigated: chewing on (a) the natural dentition (ND), (b) splints with structured occlusal profiles simulating the subject’s natural dentition (SS), (c) splints with a plane surface (PS), and (d) splints with a balancing contact in the molar region (CS). The expectorated particles were analyzed by a validated scanning procedure. The size distribution of the particles was calculated with the Rosin-Rammler function. The X50 values of the experimental conditions were compared by repeated measures analysis of variance.
Result: The results did not confirm the initially stated hypothesis. The X50 values differed significantly (p>0.01) between PS and SS, and between CS and SS, respectively. In contrast, no significant differences (p>0.05) were observed between SS and ND.
Conclusion: These findings support the assumption that tooth cusps profiles as well as disturbance of the natural chewing cycles by unexpected eccentric tooth contacts significantly influence the breakage of food particles.