Surface Quality Evaluation of Removable Thermoplastic Dental Appliances Related to Staining Beverages and Cleaning Agents

Abstract

(1) Background: Thermoplastic materials are not inert and subject to changes in the oral environment, which affect their surface quality. Color stability and topographic characteristics of clear thermoplastic appliances are critical considerations. The study aimed to evaluate the optical changes and surface topography of different thermoplastic materials related to staining beverages and cleaning agents. (2) Methods: Thermoplastic polyethylene terephthalate glycol (PET-G) material specimens were selected for the study: S (Duran, Scheu-Dental GmbH, Iserlohn, Germany), D (Biolon, Dreve Dentamid GmbH, Unna, Germany), and B (Crystal, Bio Art Dental Equipment, Sao Carlos, Brazil). Four different media were involved for immersion: coffee (C) and black tea (T) at 55 °C, Coca-Cola (K) at 5 °C, and distilled water (W) at 22 °C. As for cleaning, chemical options and mechanical brushing were selected (P-powder, T-tablets, and X-brushing). Color changes, and mean surface roughness were measured at 24 h, 48 h, and after 7 days. Statistical analysis was performed. After the testing period, atomic force microscopy (AFM) analyses and SEM images were registered in order to characterize the surface topography. (3) Results: Quantitative color change evaluations revealed a slight change in color after 24 h and an extremely marked change after 48 h, respective 7 days. Mean roughness values are kept below the clinically acceptable limit of 0.20 µm for all samples. Related to mean nanoroughness values Sa, and 3D evaluations of the surface quality, Biolon samples have demonstrated the most constant behavior, while Crystal samples are visibly influenced by water immersion. Related to the cleaning method, the topography of Duran samples was influenced by mechanical brushing. (4) Conclusions: Nanoscale investigations provided high accuracy and more realistic surface quality examinations of the examined samples compared to profilometry. Both SEM and AFM should be used for a more detailed description of the surface topography.

Clear Aligners: Between Evolution and Efficiency—A Scoping Review

“…Studies of this type simulate the environment of the oral cavity through solutions of artificial saliva and exposure to highly pigmented foods such as wine, coffee, cola, tea and different cleaning methods [ 41 ]. The most recent data, in which both PET-G and polyurethane based aligners are used, agree in affirming that there are foods that stain more than others (above all black tea), that polyurethanes are more subject to color alterations, that even the surface analysis with a scanning electron microscope shows a greater alteration of the integrity of the material, and that this becomes all the more significant the longer the aligner is used (the aligners after two weeks show values of surface alteration above the threshold level of 0.20 μm) [ 30 , 42 ]. Other authors [ 31 , 32 , 43 ] found that material properties change during the wear-time, and this may affect treatment outcomes since the intraoral aging of clear aligners (regardless of the type of material they are made of) through biofilm modifications and oral environmental conditions might have an adverse effect on material properties and stability over the treatment time, compromising the force delivery capacity and treatment efficacy.…”

“…Eight brands are mentioned in the scientific literature. Airnivol (AirNivol S.p.A, Navacchio di Cascina -Pisa, Italy) has been used in three comparative studies between systematics on fitting influenced by the thickness of the aligner, by exposure to the oral environment and in the study of the extrusion movement of the central incisor [ 29 , 30 , 53 ]. ALL IN (Micerium S.p.A., Avegno- Genova, Italy) and Arc Angel (Gruppo Dextra, Modena, Italy) have only been used in one study about the comparative analysis of the gap and thickness of different brands [ 27 ].…”

“…ALL IN (Micerium S.p.A., Avegno- Genova, Italy) and Arc Angel (Gruppo Dextra, Modena, Italy) have only been used in one study about the comparative analysis of the gap and thickness of different brands [ 27 ]. The aligner named Clear Aligner (Scheu Dental GmbH, Iserlohn, Germany) has been used in ten studies on the material (PET-G) they are made of and on its mechanical properties after the thermoforming process, exposure to saliva and different beverages, after stress relaxation due to use and cito-toxicity [ 29 , 30 , 31 , 32 , 33 , 34 , 54 , 55 , 56 , 57 ]. F22 is a system of clear aligners (Sweden & Martina SpA, Due Carrare—Padova, Italy) used for experimental research in nine studies.…”

Color changes in bulk-fill resin composites as a result of visible light-curing

“…Means were compared by Scheffe's multiple range test for post hoc analysis at 95% probability level. The average color deference of ∆E*ab was permitted by less than 1.5 (Slight change) according to NBS 8,9) . Effect size 2.14 (Cohen's d) was calculated by following formula in pilot study groups.…”

Surface Characterisation of Dental Resin Composites Related to Conditioning and Finishing

“…Previously problems related to the sealants consist of low abrasion resistance, weak retention to the applied material, poor surface quality, and microcracks [ 38 , 39 ]. Further studies should be performed in order to investigate if surface conditioning before glazing increases the bond strength between the resin-composite CAD-CAM and the sealant, after aging procedures because resin-composite are expected to be hydrophilic [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ].…”