Resin Infiltration of Natural and Artificial Root Caries Lesions

Objectives: The purpose of this study was the investigation of the infiltration of a low viscosity resin into natural and artificial initial root caries lesions.
Methods: 70 human extracted teeth were used for this investigation. 40 teeth were caries free and 30 showed initial root caries lesions. In the caries free teeth artificial root caries lesions were made using hydroxyethylcellulose at pH 4.8. 20 teeth with artificial and 10 with natural lesions were immersed in 1% sodium fluorescein and then infiltrated with resin. The teeth of the control group received no resin infiltration. All teeth were embedded into Technovit 9100 and serial sections were cut through the lesions. The sections were then investigated with fluorescence light microscopy (FLM). 20 teeth with artificial and natural lesions respectively were cut through the lesions and investigated with scanning electron microscopy (SEM) with combined element dispersive spectroscopy (EDS). Spot measurements of different lesion zones which were the superficial layer, demineralized zone and sound dentin were cried out. Additional line scans and element mappings were made. The quantitative spot measurements were analyzed statistically with non-parametric tests.
Results: Remarkable differences were found between artificial and natural root caries lesions. FLM as well as EDS line scans and mappings revealed a complete infiltration of the artificial fillings in most cases. Statistical analysis of quantitative spot measurements showed significant differences in the C content between the superficial layer and demineralized zones between the experiments and controls. Natural caries lesions demonstrated only some single superficial infiltration spots but no complete infiltration of the lesions.
Conclusions: The used resin should be adapted for infiltration of natural demineralized root dentin.