Color stability of chemically activated reline resin after microwave disinfection: a 1-year clinical trial.
OBJECTIVE
To evaluate the effect of microwave disinfection on the color stability of a hard chairside reline resin after a 1-year service period.


METHODS
40 adult patients aged between 30-75 years, who required denture reline treatment, participated in this study. Tokuyama Rebase II was used to reline complete maxillary dentures. The edentulous subjects were randomly divided into two groups (n=20) and dentures were cleansed according to two methods: CG (control group) - brushing with coconut soap and soft toothbrush; DG (disinfection group) - brushing according to previous methods and microwave disinfection once a week for 3 minutes at 650W. Color parameters in L*a*b* were recorded by spectrophotometer immediately after the reline, at 7 and 15 days, 1, 3, 6 and 9 months and 1 year post-placement. Data were analyzed by two-way repeated-measures ANOVA and Tukey tests (alpha = 0.05).


RESULTS
Color alteration values of DG were significantly lower than those of CG (P<0.05). Color changes observed after 15 days were greater than values obtained at 7 days recall (P<0.05). All color changes observed for the CG were considered noticeable (between 1.5 and 3.0 NBS). In DG, color change was slight (between 0.5 and 1.5 NBS). There were statistically significant differences between L* values obtained initially and after 3 months, between 15 days and 3 months and between 15 days and 1 year (P<0.05). No significant differences were observed between group and time for the parameters a* and b*.
Araraquara Dental School - UNESP, R. Humaitá, no 1680, CEP 14801-903 Araraquara, São Paulo, Brazil. robertachuqui@yahoo.com.br
Roberta Chuqui
RC
Ribeiro
Eunice Teresinha
ET
Giampaolo
Fernanda Emiko
FE
Izumida
Ana Cláudia
AC
Pavarina
Eduardo Buozi
EB
Moffa
Carlos Eduardo
CE
Vergani
D000328:Adult; D000368:Aged; D002253:Carbonated Beverages; D003069:Coffee; D003116:Color; D003764:Dental Materials / Q000737:chemistry / Q000528:radiation effects*; D003819:Denture Bases; D003820:Denture Cleansers / Q000627:therapeutic use; D003822:Denture Liners; D003823:Denture Rebasing; D003827:Denture, Complete, Upper; D003902:Detergents / Q000627:therapeutic use; D004203:Disinfection / Q000379:methods*; D005500:Follow-Up Studies; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry / Q000528:radiation effects; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D011446:Prospective Studies; D012907:Smoking; D013053:Spectrophotometry; D013662:Tea; D014099:Toothbrushing / Q000295:instrumentation
D003069:Coffee; D003764:Dental Materials; D003820:Denture Cleansers; D003902:Detergents; D008689:Methacrylates; D013662:Tea; C514244:tokuyama rebase fast II