Early dentine remineralisation: morpho-mechanical assessment.
OBJECTIVE
The purpose of this study was to evaluate some physical-mechanical and morphological changes of demineralised dentine at early stages of dentine remineralisation.


METHODS
Extracted human third molars were sectioned to obtain dentine discs. After polishing the dentine surfaces, three groups were established: (1) untreated dentine - UD, (2) 37% phosphoric acid application for 15s (partially demineralised dentine - PDD) and (3) 10% phosphoric acid for 12h, at 25°C (totally demineralised dentine - TDD). Five different remineralizing fluids were used for 30min: chlorhexidine (CHX), artificial saliva (AS), phosphated solution (PS), ZnCl2 and ZnO solutions. Atomic force microscopy (AFM) imaging/nano-indentation, surface nano-roughness and fibrils diameter were determined. X-ray diffraction (XRD), energy dispersive elemental analyses (EDX) and high resolution scanning electron microscopy analysis (HRSEM) were applied.


RESULTS
PDD and TDD preserved some mineral contents. After demineralisation and immersion in all solutions, width of nanomechanical properties and fibrils was increased, and total nanoroughness was decreased. Peritubular and intertubular dentine were remineralised.


CONCLUSIONS
Mineral exists in PA-demineralised dentine matrix and it is important since it may work as a constant site for further nucleation. The dentine surface remineralisation process may be stimulated as early as 30min in abiotic conditions, with a pH ranging from 7.0 to 7.5.


CONCLUSIONS
The existence of enzymes and remineralising factors within the dentine matrix may facilitate early dentine remineralisation under favourable conditions. This process should be stimulated by new reparative materials.
University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain. Electronic address: toledano@ugr.es.
Manuel
M
Toledano
University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain.
Estrella
E
Osorio
University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain.
Inmaculada
I
Cabello
University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain.
Raquel
R
Osorio
D000328:Adult; D000891:Anti-Infective Agents, Local / Q000494:pharmacology; D001696:Biomechanical Phenomena; D002327:Cariostatic Agents / Q000494:pharmacology; D002710:Chlorhexidine / Q000031:analogs & derivatives / Q000494:pharmacology; D002712:Chlorides / Q000494:pharmacology; D003094:Collagen / Q000648:ultrastructure; D003804:Dentin / Q000187:drug effects / Q000503:physiopathology / Q000648:ultrastructure*; D055119:Elastic Modulus; D004577:Electron Probe Microanalysis; D006244:Hardness; D006801:Humans; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000032:analysis; D010710:Phosphates / Q000494:pharmacology; D010756:Phosphoric Acids / Q000009:adverse effects; D012464:Saliva, Artificial / Q000494:pharmacology; D012969:Sodium Fluoride / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors; D017001:Tooth Demineralization / Q000473:pathology / Q000503:physiopathology; D014089:Tooth Remineralization / Q000379:methods*; D014961:X-Ray Diffraction; D055815:Young Adult; D017967:Zinc Compounds / Q000494:pharmacology; D015034:Zinc Oxide / Q000494:pharmacology
D000891:Anti-Infective Agents, Local; D002327:Cariostatic Agents; D002712:Chlorides; D008903:Minerals; D010710:Phosphates; D010756:Phosphoric Acids; D012464:Saliva, Artificial; D017967:Zinc Compounds; C016837:zinc chloride; D012969:Sodium Fluoride; D003094:Collagen; C030242:phosphoric acid; C010882:chlorhexidine gluconate; D002710:Chlorhexidine; D015034:Zinc Oxide
Dentine; Mechanical; Microscopy; Remineralisation; Roughness