title: Developments in denture teeth to prevent softening by food solvents.
abstract: The effect of various food-simulating solvents on the hardness of denture teeth after varying storage times, using a Martens hardness test was determined. Martens hardness (HM) was assessed at baseline and during storage up to 1 month in distilled water (DW), peppermint oil (PO), heptane (HT) and 75% ethanol (ET) for four commercially-available denture teeth; Vivodent (VIV), Double-cross-linked Postaris (DCL), Orthosit (ORT), Candulor porcelain (POR) and two polymer based experimental denture teeth: Experimental 1 (EXP1); a hybrid nanocomposite with two different sized silanated filler particles and Experimental 2 (EXP2); containing an organic copolymer based upon urethanedimethacrylate and polymethyl methacrylate. Hardness [mean (sd)] at baseline was: VIV 142 (1), DCL 142 (1), ORT 209 (9), POR 2926 (101), EXP1 285 (11), and EXP2 146 (12). One-way ANOVA using Tukey's test on polymer-based materials showed that the hardness values of ORT and EXP1 were significantly higher than those of VIV, DCL and EXP2 (P < 0.05). Moreover, EXP1 had a significantly higher hardness value than ORT (P < 0.05). Except for EXP1, all polymer based materials showed a significant drop in hardness after storage in ET (P < 0.05). Specimens stored in water, heptane and peppermint oil showed minor fluctuations in hardness, which were not statistically significant.
authors.affiliation: Restorative Dentistry, The Royal London Dental Hospital, New Road, London, UK. shakeel.shahdad@bartsandthelondon.nhs.uk
authors.forename: Shakeel A
authors.initials: SA
authors.lastname: Shahdad
authors.forename: John F
authors.initials: JF
authors.lastname: McCabe
authors.forename: Robert W
authors.initials: RW
authors.lastname: Wassell
mesh_terms: D019554:Dental Restoration Wear / Q000145:classification*; D003779:Denture Design; D003778:Dentures; D019544:Equipment Failure Analysis; D005502:Food; D006244:Hardness; D006245:Hardness Tests; D012997:Solvents / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D012997:Solvents