sodium-hypochlorite and calcium-phosphate--dibasic--anhydrous

This study aimed to evaluate the ability of a newly developed calcium-phosphate desensitizer in dentin permeability reduction and its integration with dentin surface before and after immersion in artificial saliva (AS) under two different dentin surface characteristics; with or without the collagen exposure.Humandentin discs treated by EDTA to expose collagen fibrils or EDTA/NaOCl to expose plain dentin surface were subjected to a calcium-phosphate desensitizer (Teethmate Desensitizer; TMD), while non-desensitizer treatment served as control. TMD application showed the occlusion in dentinal tubules and reduction in dentin permeability up to 92%, regardless of dentin surface characteristics. After AS immersion, permeability reduction percent (PR%) significantly increased in EDTA/NaOCl pretreatment (p<0.05). Newly-formed crystallites were observed on desensitizer treated dentin and EDTA/NaOCl pretreatment control group, whereas the crystallites did not exist on EDTA pretreatment control group. Ultrasonication revealed the integration of the calcium-phosphate rich layer of desensitizer on dentin surface after AS immersion.

Topics: Calcium Phosphates; Chelating Agents; Collagen; Crystallization; Dentin; Dentin Desensitizing Agents; Dentin Permeability; Edetic Acid; Humans; Materials Testing; Microscopy, Electron, Scanning; Oxidants; Saliva, Artificial; Smear Layer; Sodium Hypochlorite; Ultrasonics

The remineralization of acid-etched enamel after brushing with and without a non-fluoride abrasive dentifrice was investigated using scanning electron microscopy after sodium hypochlorite (NaOCl) or ethylenediamine tetra-acetic acid treatment, of the specimens. Ground enamel pieces were etched with 30% phosphoric acid for 60 s and attached to resin plates. They were exposed to the oral environment of 4 subjects for 8 weeks and brushed for 1 min daily. Paste and brushing caused the acid-etched enamel to erode selectively, i.e., deep grooves were formed in the prism peripheral regions, while projections of the prism bodies showing a relatively low density of crystallites were retained. Brushing without dentifrice, on the other hand, caused about 0.5 micron thick pellicle with tag-like structures to cover the etched enamel. Fine mineral granules, presumably derived from saliva and minute fragments of etched crystallites, were precipitated on the enamel surface as a thin layer with the pellicle. These results indicate that daily brushing without dentifrice induces the remineralization of acid-etched enamel by depositing salivary components, while paste brushing will lead to abrasion of the weakened enamel.

Topics: Acid Etching, Dental; Adolescent; Adult; Calcium Phosphates; Child; Crystallography; Dental Deposits; Dental Enamel; Dental Pellicle; Dentifrices; Edetic Acid; Female; Humans; Male; Microscopy, Electron, Scanning; Middle Aged; Phosphoric Acids; Saliva; Sodium Hypochlorite; Tooth Abrasion; Tooth Erosion; Tooth Remineralization; Toothbrushing

The prognosis of acid-etched enamel was investigated in both laboratory and clinical experiments. Acid etching produced irregularities even on the prismless layer that covers prism enamel. The irregularities produced by etching are not remineralized in vivo but are filled with organic debris. Brushing reduced the depth of the irregularities but did not eliminate them. A protective varnish against acid etching was developed. The varnish also serves as a guide to facilitate removal of excess resin beyond the cavosurface margin.

Topics: Acid Etching, Dental; Calcium Phosphates; Dental Bonding; Dental Cavity Preparation; Dental Enamel; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Phosphoric Acids; Resins, Synthetic; Saliva; Sodium Hypochlorite; Toothbrushing