Soft denture liners and sodium perborate: sorption, solubility and color change

Abstract Aim: To evaluate the sorption, solubility and color change in two lining materials after 120 days of immersion in either sodium perborate or artificial saliva. Methods: Thirty disk-shaped specimens (15×3 mm) of each material, Mucopren(r) soft (MS) and Elite(r) soft (ES) were manufactured and divided into two groups. The specimens in the control group (CG, n=15) were stored in artificial saliva at 37 °C. The specimens in the experimental group (EG, n=15) were stored in artificial saliva at 37 °C and immersed in sodium perborate daily for 5 min. The analysis of sorption and solubility was based on the initial dry weight and on the wet and dry weights after immersion. The color was assessed with a portable spectrophotometer and the NBS system. ANOVA and Tukey test (p<0.05) were used to analyze color and sorption. The solubility was analyzed by KruskalWallis test (p<0.05). Results: Sorption was higher in the EG group (0.31±0.08) than in the control group (0.26±0.05), and higher in Elite(r) soft relining (0.34±0.07) than in Mucopren(r) soft (0.23±0.06). There was no interaction between the factors. Elite(r) Soft presented a higher solubility when immersed in artificial saliva (CG: 0.16±0.07 and EG: 0.13±0.06; p=0.00). Mucopren(r) soft showed no solubility in either treatment. Regarding the color changes, there was a significant difference between the groups (CG: 9.2±1.2 and EG: 9.9±1.2; p=0.025) but not between the materials (Mucopren(r) soft: 9.4±1.3 and Elite(r)soft: 9.7±1.0; p=0.34). Using the NBS system, we verified that both materials presented a high color change. Conclusions: The daily use of sodium perborate promoted changes in the liners' sorption and color. Elite(r) soft relining was more prone to changes than Mucopren(r) soft.

Oral health related quality of life of edentulous patients after denture relining with a silicone-based soft liner.

BACKGROUND: Knowledge of benefits caused by a treatment on quality of life is very relevant. Despite the wide use and acceptance of soft denture liners, it is necessary to evaluate the patient's response about the use of these materials with regard to improvement in oral health related quality of life (OHRQoL). OBJECTIVES: The aim of this study was to evaluate the influence of denture relining in the OHRQoL of edentulous patients. MATERIALS AND METHODS: Thirty-two complete denture wearers had their lower dentures relined with a silicone-based material (Mucopren soft, Kettenbach, Germany) according to chairside procedures. OHRQoL was assessed before and after 3 months of relining by means of OHIP-EDENT, and the median scores were compared by Wilcoxon test (p ≤ 0.05). RESULTS: After 3 months of relining, participants reported significant improvement of their OHRQoL (p ≤ 0.01). CONCLUSION: Denture relining with a soft liner may have a positive impact on the perceived oral health of edentulous patients.

Bond strength and degree of infiltration between acrylic resin denture liner after immersion in effervescent denture cleanser.

PURPOSE: The purpose of this study was to investigate the effect of sodium perborate on the bond strength and degree of infiltration between acrylic resin/resilient denture liners. MATERIALS AND METHODS: Three denture liners (Elite Soft, Mucopren Soft, Kooliner) were investigated. Twenty specimens (83 x 10 x 10 mm(3)) of each material were made by processing the denture liners against two polymerized PMMA blocks. Ten specimens for each material were stored in artificial saliva at 37 degrees C (control group: TBS1), and the other ten specimens were stored in artificial saliva at 37 degrees C combined with sodium perborate (experimental group: TBS2). All specimens were placed under tension until failure in a Universal Testing Machine at a crosshead speed of 5 mm/min after 7 (T7) and 60 (T60) days (n = 5). Failure strength (MPa) was recorded, and mode of failure was characterized as cohesive, adhesive, or cohesive/adhesive. For the infiltration tests, ten circular specimens (14-mm diameter x 2-mm thick) of each material were stored in artificial saliva and 0.5% methylene blue at 37 degrees C (control group: I1), and ten specimens were stored in artificial saliva and 0.5% methylene blue at 37 degrees C combined with daily immersions for 5 minutes in an effervescent solution of sodium perborate (experimental group: I2). The degree of infiltration was obtained through photographs and using Software Image Tool after 120 days. RESULTS: For Kooliner, the statistical test did not show a significant difference in the bond strength due to the influence of the immersion period or to the use of sodium perborate. Elite Soft presented a significant increase in the average tension in T7 and in T60 in both TBS1 and TBS2. Inversely, the Mucopren suffered a significant decrease in the tension value in the same period as the TBS1 group as well as in the TBS2. The infiltration percentage was analyzed with the Kruskal-Wallis test (26.18; p < 0.05), which indicated significant differences between the compared averages for the groups. Comparing the averages of materials, the statistical test did not show significant differences between the control (I1) and experimental (I2) groups after 120 days. CONCLUSIONS: The use of sodium perborate did not promote significant alterations in the evaluated properties. Kooliner presented the best results.

Effect of a denture cleanser on hardness, roughness and tensile bond strength of denture liners

Aim: This study aim to investigate the effect of a denture cleanser on hardness, roughness and tensile bond strength of a rigid (Kooliner) and a soft denture liner (Elite Soft) after 7, 60 and 120 days of immersion. Methods: Thirty circular and twenty rectangular specimens of each material were randomly distributed in two groups: control - immersion in artificial saliva at 37°C; and experimental - immersion in artificial saliva at 37ºC combined with immersion in the cleanser for 5 min. Hardness was measured using either a Vickers or Shore A hardness tester, and a surface roughness tester was used to measure the surface roughness. Tensile bond strength was carried out on a universal testing machine. Data were analyzed statistically by ANOVA or Kruskal-Wallis test (alpha=0.05). Results: No significant difference was found between the groups for the tested properties (p>0.05). There was an increase in the hardness of both materials after 60 days (p>0.05). No difference between the immersion periods was found for the roughness of Kooliner (p>0.05), although the roughness of Elite Soft decreased after 120 days in both groups (p>0.05). Kooliner presented higher tensile bond strength than Elite Soft (p>0.05). Conclusions: Both materials showed alterations on the tested properties during the experimental period, but these changes were not promoted by the denture cleanser.