In Vitro effect of denture cleansers on the color stability of polyetheretherketone and other denture base polymers / Efecto in vitro de los limpiadores de prótesis en la estabilidad del color de la polieteretercetona y otros polímeros base de prótesis

Abstract The aim of this in vitro study was to compare the long-term effect of overnight use of denture cleansers with different chemical compositions on the color stability of denture base polymers (DBPs). The four DBPs evaluated were PEEK (PK group), thermoinjection-molded polyamide (PA group), auto-polymerized polymethylmethacrylate (PMMA) (AP group), and heat-polymerized resin PMMA (HP group). The cleaning agents used were Corega tablet (CT), Protefix tablet (PT), and 0.5% sodium hypochlorite (NaOCl) solution (SH). Distilled water (DW) served as a control. Forty-eight disc-shaped specimens (10mm × 2mm) were prepared from each DBP and randomly immersed in the different storage media (n=12 in each group). Color measurements of the specimens before and after immersion in the denture cleansers were made using a spectrophotometer (VITA Easyshade V). The color changes were measured and recorded in L* a* b*. After 120 d, the CIEDE2000 formula was used to calculate color changes (ΔE00). For analysis of the data, a multivariate analysis of variance was used (p<0.05). The results of the statistical analysis revealed significant color change differences in the DBPs immersed in the various denture cleansers (p<0.05). Groups PA and PK showed the highest values for all solutions. AP-SH showed the highest ΔE00 value in group AP, no significant difference was found between other solutions. In group HP, there was no statistically significant difference between the average ΔE00 values of all solutions. Long-term daily use of the denture cleansers affected the color stability of all the DBPs, although the level of color change was acceptable. Laboratory and clinical studies on the color stability of PEEK are needed to confirm the results of this study.

Resumen El objetivo de este estudio in vitro fue comparar el efecto a largo plazo del uso nocturno de limpiadores de prótesis con diferentes composiciones químicas sobre la estabilidad del color de los polímeros base de prótesis (DBP). Los cuatro DBP evaluados fueron PEEK (grupo PK), poliamida moldeada por termoinyección (grupo PA), polimetilmetacrilato (PMMA) autopolimerizado (grupo AP) y resina PMMA termopolimerizada (grupo HP). Los agentes de limpieza utilizados fueron Corega (CT), Protefix (PT) y la solución de hipoclorito de sodio (NaOCl) al 0,5% (SH). El agua destilada (DW) sirvió de control. Se prepararon 48 especímenes en forma de disco (10mm × 2mm) de cada DBP y se sumergieron al azar en los diferentes medios de almacenamiento (n=12 en cada grupo). Las mediciones del color de las muestras antes y después de la inmersión en los limpiadores de dentaduras se realizaron con un espectrofotómetro (VITA Easyshade V). Los cambios de color se midieron y registraron en L* a* b*. Después de 120 d, se utilizó la fórmula CIEDE2000 para calcular los cambios de color (ΔE00). Para el análisis de los datos, se utilizó un análisis multivariante de la varianza (p<0,05). Los resultados del análisis estadístico revelaron diferencias significativas en el cambio de color de los DBP sumergidos en los distintos limpiadores de dentaduras (p<0,05). Los grupos PA y PK mostraron los valores más altos para todas las soluciones. AP-SH mostró el valor ΔE00 más alto en el grupo AP, no se encontraron diferencias significativas entre las demás soluciones. En el grupo HP, no hubo diferencias estadísticamente significativas entre los valores medios de ΔE00 de todas las soluciones. El uso diario a largo plazo de los limpiadores de dentaduras afectó a la estabilidad del color de todos los DBP, aunque el nivel de cambio de color fue aceptable. Se necesitan estudios de laboratorio y clínicos sobre la estabilidad del color del PEEK para confirmar los resultados de este estudio.

Effect of Different Denture Base Cleansers on Surface Roughness of Heat Polymerised Acrylic Materials with Different Curing Process / Efecto de diferentes limpiadores para dentaduras en la rugosidad de la superficie de acrílicos polimerizados por calor con diferentes procesos de curado

Abstract Avoiding biofilm formation on dentures is associated with maintaining the surface properties of acrylic-based dentures. The aim of the study is to investigate the effects of two different cleaning agents (Corega and Klorhex 0.2% chlorhexidine gluconate) on surface roughness of the denture regarding efficacy of curing procedures. A total of sixty disc-shaped specimens were prepared with two different methods as long and short curing processes. The specimens were divided into subgroups according to the immersion solutions (distilled water, Corega tablet group and Klorhex 0.2% chlorhexidine gluconate group) (n=10). The samples were kept in a solution for 8 hours per day during a month. The average Ra1 (before exposure to the cleanser agent) and Ra2 (after exposure to the cleanser agent) of each sample was measured. A two- way ANOVA and post hoc Tukey test was used for statistical analysis. The solutions significantly increased the Ra values in both acrylic groups (p0.05). The long-term curing time is highly effective in decreasing the surface roughness of the acrylic base material.

Resumen Evitar la formación de biopelículas en las prótesis dentales se asocia con el mantenimiento de las propiedades de la superficie de las prótesis de base acrílica. El objetivo del estudio es investigar los efectos de dos agentes de limpieza diferentes (Corega y Klorhex 0,2% gluconato de clorhexidina) en la rugosidad de la superficie de la dentadura postiza en cuanto a la eficacia de los procedimientos de curado. Se prepararon un total de sesenta muestras en forma de disco con dos métodos diferentes como procesos de curado largos y cortos. Las muestras se dividieron en subgrupos según las soluciones de inmersión (agua destilada, grupo de pastillas Corega y grupo de gluconato de clorhexidina al 0,2%) (n=10). Las muestras se mantuvieron en una solución durante 8 horas al día durante un mes. Se midió el promedio de Ra1 (antes de la exposición al agente de limpieza) y Ra2 (después de la exposición al agente de limpieza) de cada muestra. Para el análisis estadístico se utilizó un ANOVA de dos vías y una prueba post hoc de Tukey. Las soluciones aumentaron significativamente los valores de Ra en ambos grupos acrílicos (p 0,05). El tiempo de curado a largo plazo es muy eficaz para disminuir la rugosidad de la superficie del material de base acrílica.

The staining effect of coffee and red tea to two kinds of denture base materials and the cleaning efficacy of four kinds of denture cleansers to the stains / 口腔疾病防治

Objective@#To compare the staining effect of coffee and red tea to the different denture base materials, and to investigate the cleaning efficacy of four denture cleansers.@*Methods @#All samples were separately soaked in 1％NaClO、 Efferdent、 Polident partial and Polident overnight for 12 times within 12 days after staining by the coffee and red tea. Then, the color values of the samples were measured by the spectrocolorimeter. @*Results @#The staining effect between coffee and red tea in the two materials was statistically significant (P < 0.05); the invisible denture materials are easily colored than heat-curing denture base resins (P < 0.05); there was also a statistical difference in the cleaning effect of the denture cleaning agents at each cycle stage (P < 0.05); the trend is different in different phases of color difference (ΔE) (P < 0.05). @*Conlusion@#Compared with the Polident partial, the cleaning efficacy of 1％NaClO、Efferdent and Polident overnight were better.

The staining effect of coffee and red tea to two kinds of denture base materials and the cleaning efficacy of four kinds of denture cleansers to the stains / 口腔疾病防治

Objective@#To compare the staining effect of coffee and red tea to the different denture base materials, and to investigate the cleaning efficacy of four denture cleansers.@*Methods@#All samples were separately soaked in 1％NaClO、 Efferdent、 Polident partial and Polident overnight for 12 times within 12 days after staining by the coffee and red tea. Then, the color values of the samples were measured by the spectrocolorimeter.@*Results @#The staining effect between coffee and red tea in the two materials was statistically significant (P < 0.05); the invisible denture materials are easily colored than heat-curing denture base resins (P < 0.05); there was also a statistical difference in the cleaning effect of the denture cleaning agents at each cycle stage (P < 0.05); the trend is different in different phases of color difference (ΔE) (P < 0.05).@*Conlusion@#Compared with the Polident partial, the cleaning efficacy of 1％NaClO、Efferdent and Polident overnight were better.

A Narrative Review of Different Types and Processing Methods of Acrylic Denture Base Material

@#Acrylic resin is commonly used to fabricate removable prostheses due to its adequate physical, mechanical properties and cost effectiveness. There has been continuous development of the materials to improve their properties and to widen its application in different clinical setting. To study the history development of the acrylic resin and elaborate on the properties of different types and the processing methods of acrylic resins used to fabricate denture base which are commercially available in the market. This would help the dental clinician in choosing the best material of choice. The authors have summarized the history, development and classification of different types of acrylic resins used in fabricating denture and processing methods based on all the published research available on this topic using published materials available in the Dental Library, University of Malaya and the database (Science Direct, PubMed). Every type of acrylic denture base material has its pros and cons. Therefore, careful selection of material and the processing method is crucial to ensure the best outcome for prosthodontic treatment. Hence, upholding the patients’ best interest and improving their quality of life.