Polymaleic acid-calcium complexes induce intrafibrillar mineralization and dentin remineralization as well as occlusion of dentinal tubules

Objectives The aim of this study is to evaluate the effectiveness of polyelectrolyte-cation complexes pre-precursor (PCCP) process using polymaleic acid (PMA) for inducing intrafibrillar mineralization, dentin remineralization and occlusion of dentinal tubules. Methods Collagen fibrils were successively treated with PMA-Ca suspension and phosphate solution, 5 min each, and incubated in artificial saliva for 2 days. Demineralized dentin of human dentin disks and rabbit’s incisors were treated as aforementioned, 20 min each, and followed by 2 days of incubation. They were identified by scanning/transmission electron microscopy (SEM/TEM) and high resolution TEM (HRTEM) with selected area electron diffraction (SAED). The mechanical properties of de- and remineralized dentin were evaluated by nanoindentation test. The dentin permeability testing of de- and remineralized dentin treated with different ways was conducted. The oral mucosa irritations of mineralization media were evaluated. Results The intrafibrillar mineralization and in vitro/in vivo remineralization of demineralized dentin were successfully achieved. The mechanical properties of remineralized dentin were recovered from demineralized dentin ( P  < 0.001) close to natural dentin ( P   >  0.05). The dentinal tubules were occluded exceeding 100 µm and dentin permeability was significantly decreased ( P  < 0.001). No evident mucosa irritation was detected. Conclusions The PMA-Ca suspension following phosphate group could effectively induce in vitro/in vivo remineralization of demineralized dentin with in-depth occlusion of open dentin tubules and great reduction of dentin permeability. The effectiveness of PCCP process using PMA was validated. Clinical significance The PCCP process using PMA could be used for management of dentin caries and dentin hypersensitivity.