title: Impact of Types of Moisturizer and Humidity on the Residual Weight and Viscosity of Liquid and Gel Oral Moisturizers.
abstract: OBJECTIVE
  Oral moisturizers need to be selected based on their material properties. The purpose of this study was to investigate the effects of moisturizer type and humidity on the residual weight and viscosity of oral moisturizers.
  
  
  METHODS
  The weight and viscosity of 17 oral moisturizers (7 liquid and 10 gel) at baseline and after 8 hours were measured using an incubator maintained at 37°C at either 85% or 40% relative humidity (RH). The rate of change in weight (RCW) and the rate of change in viscosity (RCV) were calculated. Data were analyzed with two-way analysis of variance (ANOVA) and Scheffe's test to evaluate the effect of the type of moisturizer (liquid or gel) and humidity (85% or 40% RH) on RCW and RCV. Pearson's correlation coefficient was used to evaluate the relationship between RCW and RCV.
  
  
  RESULTS
  Two-way ANOVA results indicated that the type of moisturizer and RH had a significant effect on RCW and RCV (p < 0.05); however, the interaction between them was not significant. The results of multiple comparisons showed that gel moisturizers had a significantly lower RCW and higher RCV than liquid moisturizers (p < 0.05). The RCW and RCV at 40% RH were significantly higher than those at 85% RH (p < 0.05). There was no correlation between RCW and RCV in the liquid moisturizer group, but a significant negative correlation was found in the gel moisturizer group (pp = 0.01).
  
  
  CONCLUSIONS
  Because viscosity of gel moisturizers increases as weight decreases, selecting gel moisturizers with a minimal change in weight and viscosity would be preferable in the case of a long-time application and severe dry mouth.
authors.affiliation: Denture Prosthodontics Restoration, Kagoshima University Medical and Dental Hospital, Kagoshima, Japan. kaku@dent.kagoshima-u.ac.jp.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Murakami
authors.affiliation: Department of Oral and Maxillofacial Prosthodontics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nishi
authors.affiliation: Department of Oral and Maxillofacial Prosthodontics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Fujishima
authors.affiliation: Denture Prosthodontics Restoration, Kagoshima University Medical and Dental Hospital, Kagoshima, Japan.
authors.forename: Misaki
authors.initials: M
authors.lastname: Nishio
authors.affiliation: Denture Prosthodontics Restoration, Kagoshima University Medical and Dental Hospital, Kagoshima, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Minemoto
authors.affiliation: Department of Biomaterials Science, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
authors.forename: Takahito
authors.initials: T
authors.lastname: Kanie
authors.affiliation: Department of Oral and Maxillofacial Prosthodontics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nishimura
mesh_terms: D004643:Emollients; D006801:Humans; D006813:Humidity; D014783:Viscosity; D014987:Xerostomia / Q000628:therapy
chemical_list: D004643:Emollients
keywords: Oral moisturizers; dry mouth; humidity; viscosity