title: Replica of human dentin treated with different desensitizing agents: a methodological SEM study in vitro.
abstract: This is a preliminary study to determine a methodological sequence in vitro which may allow the reproduction of dentin for SEM analysis, after the use of different desensitizing agents. Dentin discs obtained from extracted human third molars were etched with 6% citric acid, an artificial smear layer was created and the surface dentin discs were divided into four quadrants. Quadrants 2, 3 and 4 of each disc were conditioned with 6% citric acid. The desensitizing agents (Oxa-Gel, Gluma Desensitizer and an experimental agent) were applied to quadrants 3 and 4. To evaluate the acid resistance of the treatment, quadrant 4 was etched again with 6% citric acid. An impression was then taken with Aquasil ULV. After a setting period of 6 min, each disc was removed from the impression and stored in a moist-free environment for 24 h at 37 degrees C. After that time, a low-viscosity epoxy resin (Araltec GY 1109 BR) was poured into the impression and cured for 24 h. All specimens were metal-coated for SEM analysis. Comparison of the photomicrographs of dentin discs with their respective impressions and resin replicas showed that this technique can reproduce the characteristics of the dentin surface treated with desensitizing agents.
authors.affiliation: Dentistry, Endodontics and Dental Materials Department, Bauru School of Dentistry, University of Sao Paulo, Brazil. jcper@fob.usp.br
authors.forename: Jose Carlos
authors.initials: JC
authors.lastname: Pereira
authors.forename: Ana Christina Bonato Figueiredo
authors.initials: AC
authors.lastname: Martineli
authors.forename: Ming S
authors.initials: MS
authors.lastname: Tung
mesh_terms: D000134:Acid Etching, Dental; D002130:Calcium Phosphates / Q000494:pharmacology; D002482:Cellulose / Q000031:analogs & derivatives / Q000494:pharmacology; D019343:Citric Acid; D003760:Dental Impression Materials / Q000737:chemistry; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D003807:Dentin Sensitivity / Q000473:pathology / Q000517:prevention & control*; D004853:Epoxy Resins / Q000737:chemistry; D005976:Glutaral / Q000494:pharmacology; D006046:Gold / Q000737:chemistry; D006801:Humans; D008689:Methacrylates / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D010070:Oxalates / Q000494:pharmacology; D020011:Protective Agents / Q000494:pharmacology*; D016628:Replica Techniques; D016369:Smear Layer; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: D002130:Calcium Phosphates; D003760:Dental Impression Materials; D004853:Epoxy Resins; D008689:Methacrylates; D010070:Oxalates; D020011:Protective Agents; C485828:alpha-tricalcium phosphate; C111486:gluma desensitizer; C470050:oxa-gel; C485830:tetracalcium phosphate; D019343:Citric Acid; C485838:calcium phosphate, monobasic, anhydrous; D006046:Gold; D002482:Cellulose; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous; D005976:Glutaral