Preparing Carious Lesions for Treatments with Polymer-Induced Liquid-Precursor Method
Objectives: The Polymer-Induced Liquid-Precursor (PILP) method has been proven to reintroduce apatite mineral into collagen fibrils and to reinforce demineralized dentin. Caries lesions are complex and not homogenous.We hypothesized that conservative removal of carious dentin, utilizing polymer bur treatment or biochemical/chemical removal, allows for remineralization of the recoverable portions of the lesion by the PILP-process; with poly-Aspartic acid restoring the properties and structure of the affected dentin significantly when compared to calcium phosphate solutions only. Methods: Specimens were selected for x-ray and micro-CT analysis based on presence and location of natural lesion. Enamel was removed from lesion top (carbide bur). Two groups, mechanical removal with a polymer bur (SS White-NJ, USA) or biochemical/ chemical removal using PapacarieR (Sao Paulo, Brazil) (digested dentin removed with curette) were analysed and compared to removal of demineralized dentin. After removal both sets of samples were coated with a PILP- releasing GIC before being restored (flowable resin composite) and immersed into SBF for up to 4 weeks. Results: Neither Papacarie nor polymer burs removed the collagenous matrix of demineralized dentin suggesting that chemical-mechanical treatment allows for the removal of infected, dentin while preserving the healthy portions of the affected dentin structure. Restoration with glass ionomer cement with pAsp resulted in the formation of a mineral layer on the lesion surface and within the matrix of the dentin lesion. Dentin tissue is conserved using these removal techniques allowing for functional remineralization using the PILP method. Conclusions: The application of minimal-invasive techniques in combination with PILP-releasing cement liners may constitute a suitable way to repair dentin caries and to conserve dental tissue augmenting the lifetime of the tooth