Biomimetic Mineralizing Agents Recover the Micro Tensile Bond Strength of Demineralized Dentin

Abstract

Biomimetic remineralization is an approach that mimics natural biomineralization, and improves adhesive procedures. The aim of this paper was to investigate the influence of Dentin Caries-like Lesions (DCLL)-Producing Model on microtensile bond strength (μTBS) of etch and rinse adhesive systems and investigate the effect of remineralizing agents such as Sodium Fluoride (NaF), MI Paste™ (MP) and Curodont™ Repair (CR) on caries-affected dentin (n = 6). Nine groups were established: (1) Sound dentin; (2) Demineralized dentin/Chemical DCLL: (3) Demineralized dentin/Biological DCLL; (4) Chemical/DCLL + NaF; (5) Chemical/DCLL + MP; (6) Chemical/DCLL + CR; (7) Biological/DCLL + NaF; (8) Biological/DCLL + MP; (9) Biological/DCLL + CR. Then all dentin blocks were subjected to a bonding procedure with Adper™ Single Bond 2 adhesive system/Filtek Z350XT 4 mm high block, following this they were immersed in deionized water/24 h and then sectioned with ≅ 1 mm² beams. The μTBS test was conducted at 1 mm/min/500 N loading. Failure sites were evaluated by SEM (scanning electron microscopy (150×). μTBS data were submitted to factorial ANOVA and Tukey's test (p < 0.05). The highest values were found when demineralized dentin was treated with MP and CR, regardless caries lesion depth (p < 0.05). There was a predominance of adhesive/mixed in the present study. It was concluded that the use of the artificial dentin caries production models produces differences in the μTBS. Additionally MP and CR remineralizing agents could enhance adhesive procedures even at different models of caries lesion.

Keywords: dentin; desmineralization; microtensile bond strength.

Figure 1

Experimental design. DDC—demineralized dentin provided by chemical model; DDC/NaF-DDC + 2% NaF; DDC/MP-DDC + MI Paste™; DDC/CR-DDC + Curodont™ Repair; DDB—demineralized dentin provided by biological model; DDB/NaF-DDB + 2% NaF; DDB/MP-DDB + MI Paste™; DDB/CR-DDB + Curodont™ Repair.

Figure 2

(A) Artificial caries lesions provided by Chemical Model; (B) Artificial caries lesions provided by Biological Model after removing the softened tissue; (C) Sound Dentin.

Figure 3

Distribution of failure modes. DDC—Demineralized Dentin by chemical model; DDB—Demineralized Dentin by biological model; NaF—Sodium Floride; MI Paste™-CPP-ACP—Casein phospopeptide-amorphous calcium phosphate; Curodont™ Repair—P₁₁-4—Peptide self-assembly.

Figure 4

SEM image of failure modes. (A) Cohesive failure in Resin Composite; (B) Adhesive failure; (C) Mixed failure and (D) Cohesive failure in Dentin. Abbreviations shows areas of Co. Composite; Ad. Adhesive; De. Dentin.