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Evaluation of a Realistic Cleansing Protocol for Preventing Discoloration of Denture Resins
Author(s) -
Zoidis Panagiotis,
Polychronakis Nikolaos,
Lagouvardos Panagiotis,
Polyzois Gregory,
Ngo Hien Chi
Publication year - 2019
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/jopr.12763
Subject(s) - colorimeter , acrylic resin , dentistry , materials science , tap water , medicine , composite material , optics , physics , environmental engineering , coating , engineering
Purpose To evaluate the efficacy of a realistic staining/cleansing protocol for long‐term prevention of discoloration of denture base resins. Materials and Methods Sixty discs (20 × 2.5 mm) of auto‐ and heat‐polymerizing denture acrylic resins were fabricated following manufacturer's instructions, polished on one side and stored in water (37°C) for 24 hours before they were assigned randomly into 6 groups (3 for each material, n = 10) to receive 220 cycles of three immersion protocols. Group A was immersed in the following baths: (1) filtered coffee at 45°C for 2 minutes, (2) tap water at 24°C for 20 seconds, (3) as bath 1, (4) as bath 2, (5) Corega Extradent cleansing solution at 45°C for 3 minutes, and (6) water at 24°C for 20 seconds. Group B was immersed in the four first baths of group A (without cleansing action) and group C in bath 1 for the cumulative action of 20 cycles (80 minutes in 45°C coffee) and bath 2 for 40 seconds. A noncontact optical interferometric profilometer was used for qualitative evaluation of the specimens and a contact colorimeter to estimate color change values (ΔΕ*ab) at baseline and every 20 cycles in the baths for a total of 220 cycles. Data were statistically analyzed using a 2‐way‐repeated measures ANOVA with Bonferoni multiple comparisons and trend analysis at α = 0.05 level of significance. Results Data indicated changes in color from 1.7 to 14.2 ΔΕ*ab units. The highest values were related to the number of cycles and group B immersion protocol. Significant differences were found among immersion protocols ( p < 0.001) and immersion cycles ( p < 0.001) with a significant interaction between protocols and cycles ( p < 0.001) but not between denture resins ( p = 0.991). Conclusion The evaluated protocol A was found effective in preventing color changes in both denture resins even after a long period of action. Protocol C had a much lower staining effect on both resins than protocol B and behaved similarly to protocol A until 140 to 160 cycles. Therefore, it is probably not appropriate for use in short‐term color stability experiments.