Enhancing Tooth Remineralization around Class V Restorations

Caries is an increasing problem.  While fluoride releasing materials reduce recurrent caries rates, to improve remineralization a paste of amorphous calcium phosphate containing fluoride has been developed (GC MI Paste Plus).  Objectives: To measure demineralization in dentin and enamel around class V restorations made of glass ionomer (GC Fuji II LC) or composite resin (3M ESPE Z-100 Restorative) with and without a daily application of GC MI Paste Plus.  Methods: 40 class V preparations were made on the buccal surfaces of extracted human teeth.  20 were restored with composite and 20 were restored with glass ionomer.  Nail polish was applied to each tooth excluding a 2 mm area surrounding each restoration and the restoration itself.  Specimens were incubated in artificial caries solution (pH = 4.5).  Paste was applied daily over half the composite and glass ionomer restorations and their surrounding, exposed tooth areas.  Paste was not applied to the remaining 20 teeth.  After 24 days, specimens were sectioned, polished to 100 µm and mounted on microscope slides. Wall lesion depths were measured using a digital image-analysis system interfaced with a polarizing microscope.  Lesion depths were examined for intergroup differences using ANOVA and Tukey/Kramer post-hoc tests (p=0.05).  Results: Enamel lesion depths were significantly reduced (p<0.05) with applications of GC MI Paste Plus around composite restorations, while dentin lesions were not.  However, dentin lesion depths were significantly reduced (p<0.05) by an application of GC MI Paste Plus around glass ionomer restorations, but enamel lesions were not.  Conclusions: Our results provide direct evidence that GC MI Paste Plus significantly reduces tooth demineralization in an acid gel model. These results suggest GC MI Paste Plus may be a strong treatment option for reducing secondary caries risk in patients with diminished salivary production.  Partially supported by T35-HL07473.