The influence of cervical lesion on the stress state and strength of tooth with occlusal restoration: a numerical model study.

This paper is concerned with bio-engineering problems in dentistry. The analysis of stress in a lower premolar with a deep non-carious cervical lesion and restored occlusal Class I cavity under occlusal load of 100 N was shown. Finite element method was used for the analysis of a two-dimensional model of a human tooth. In order to facilitate the evaluation of the loads, four cross-sections in characteristical points of the model were made. The model was generated and the calculations were done on IBM Pentium III personal computer. The principal and equivalent stresses were calculated and used in qualitative and quantative evaluation of tooth tissue and tooth restoration strength. The results are shown in figures and charts. The analysis of the cross-sections distant to the cervical area has proved that the presence or absence of cervical lesion has no significant influence on the values and stress distribution. Only in the region of sharp-shaped notch in the bottom of defect (4-4) high stresses in the tooth tissues occur. The values of stress did not exceed the compressive and tensile strength in any case under investigation. The study has shown that the presence of cervical angular lesion does not affect the mechanical strength of a tooth with a properly restored occlusal cavity. Clinically, the situation is safe from the biomechanical point of view.