Natural Carious Lesions in Dentin Remineralized by PILP-Treatments

Objectives: Herein, we examine the remineralization efficacy of different Polymer Induced Liquid Precursor (PILP)-releasing methodologies on natural lesions when used with or without liner cement and restored with commercially available restorative materials.
Methods: Extracted and sterilized molar teeth with cavitated lesions in dentin were selected (n = 15). Caries was removed minimally using high speed diamond bur for enamel to subsequently remove infected dentin using a low speed diamond bur while leaving affected dentin of up to 1mm thickness behind. pAsp (poly-Aspartic Acid) (27kD, Alamanda Polymers, Inc) was applied in two ways: First, mixed with a bioactive BioglassR-based liner and applied to lesions prior to sealing with resin modified glass ionomer (RMGI) and (B) pAsp was added at concentration of 5 mg/ml in calcium phosphate solutions to rehydrate lesions before restoring with RMGI. Lesions restored with RMGI only, served as controls. Natural dentin caries lesions with approximately 1mm depth were treated and remineralized over 4 weeks. Mineral density was determined using apatite mineral phantoms with micro-computed tomography at 2 and 4 weeks per group. Density profiles were studied for two teeth per group throughout each ROI. ROI was defined as a line from EDJ to 2mm across the lesion in 2D slices (3 slices per tooth). The lesion area at different time points was calibrated versus baseline area, where 1.1 g/mm³ was a cut-off point of sound dentin.
Results: According to our analysis, there was no change in lesion size for rehydrated RMGI formulations at two weeks and four weeks. Remineralization was best achieved using bioglass as liner, which was significantly higher compared to other groups (P<0.05), reducing the lesion size by 37% at four weeks. In contrast, control samples showed decreased mineral density with treatment and the lesion size increased by 5%.
Conclusions: Evaluation of mineral density across the lesion and under cavity showed remineralization for bioglass-PILP, thereby highlighting the efficiency of PILP for natural dentin carious lesions remineralization at only 4 weeks of application.