Surface characterization of polymers used in fabrication of interim prostheses after treatment with photopolymerized glaze

Abstract

The material used for interim prostheses fabrication must present excellent physical properties for greater longevity in the face of environmental conditions, which can occur in the oral cavity. The purpose of this study was to evaluate the effect of a photopolymerized glaze on the physical and mechanical properties of polymers used for the fabrication of interim prostheses, before and after thermocycling and immersion in staining solutions. One hundred samples of composite and acrylic resins were fabricated: Dencor chemically activated acrylic resin (CAAR) (n=20) and heat-polymerized acrylic resin (HPAR) (n=20), Charisma (n=20), Structur (n=20), and Protemp (n=20). A mechanical polishing was performed on half of the samples, and a chemical polishing was performed on the remaining samples. Subsequently, all samples were submitted to thermocycling and immersion in coffee staining solution for 21days. Analysis of color and microhardness, as well as atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive x-ray spectrometry (EDS) were performed. The data were submitted to repeated-measures analysis of variance (ANOVA), followed by the Tukey test (α=0.05) and the Student t-test (α=0.05). It was verified that the glaze decreased the chromatic alteration values, and increased the microhardness values of the samples, with the exception of the Charisma resin. The samples that did not receive chemical polishing had the greatest number of surface irregularities. This study concluded that the groups with glaze presented less color alteration. In addition, Charisma and Structur resins exhibited the greatest chromatic stability. As to the microhardness, the values were greater when the samples were treated with the glaze, with the exception of the Charisma group.

Influence of a light‐activated glaze on the adhesion of Streptococcus sanguinis to the surface of polymers used in fabrication of interim prostheses

“…17 The bacterial adhesion values of groups with glaze were also higher after thermocycling, except for the bis-GMA group, because surface degradation of the glaze might have occurred. 17 It is known that surface roughness and surface energy are the most important factors in influencing bacterial adhesion, with roughness being the main factor. 11 However, surface energy and roughness were not correlated with bacterial adhesion in the present study.…”

“…The high amount of small inorganic particles in this resin might have influenced the results . Thus, the excellent surface smoothness of the bis‐GMA resin may be favorable in the application of glaze, because it prevents or reduces formation of superficial streaks and bacterial retention after its application . The bacterial adhesion values of groups with glaze were also higher after thermocycling, except for the bis‐GMA group, because surface degradation of the glaze might have occurred …”

“…58376816.7.0000.5420). A total of 36 specimens of each resin (10‐mm diameter, 3‐mm thickness) were prepared and divided into four groups: heat‐activated acrylic resin (HAAR) (Dencor, Artigos Odontológicos Clássico LTDA); chemically‐activated acrylic resin (CAAR) (Dencor); bis‐acryl (Protemp; 3M ESPE); and bis‐GMA (Charisma; Heraeus Kulzer) composite resin. Specimens were prepared according to the manufacturers’ recommendations , and were distributed based on the type of polishing (chemical and mechanical) and thermocycling period (before and after).…”

Effect of glaze and chlorhexidine on physical and mechanical properties of bis-acryl resin: An in situ study

“…3,6 Color stability is the property of a material to retain its color for a period of time in a given environment. 7 The color change can be influenced by the surface degradation of the polymeric material, as the degraded areas can serve as deposits of pigments present in various substances, such as CHX. 3,7,8 Adequate microhardness is also important because it is related to the wear resistance of the material, which in turn is important for preserving its surface integrity over time.…”

Evaluation of a glaze polishing technique for pigmented denture acrylic resin submitted to thermocycling and disinfection

“…[14,15] Now, a new method has been reported in published literature; a surface coating with a photopolymerized glaze. [9,10] Dental materials suffer constant degradation during the rehabilitation process and clinical use, which can lead to a modification in their mechanical and physical properties. [16] Constant contact with humidity and alternating temperatures in the oral cavity are examples of stress on the material.…”