scholarly journals Color Stability, Chemico-Physical and Optical Features of the Most Common PETG and PU Based Orthodontic Aligners for Clear Aligner Therapy

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 14
Author(s):  
Valeria Daniele ◽  
Ludovico Macera ◽  
Giuliana Taglieri ◽  
Loredana Spera ◽  
Giuseppe Marzo ◽  
...  

It is difficult to find research papers collecting comparative results about characterization studies of clear aligners. Therefore, the aim of this paper is to provide the first comparative analysis of most commercial clear aligners, in terms of their stability towards intra-oral staining agents, their physicochemical and optical properties, as well as their water absorption behavior. Five types of aligners, characterized by different techniques, are considered: Erkodur, Essix Plastic, Ghost Aligner, Zendura, and Invisalign. The obtained results show that clear aligners are made up of PETG, semi rigid PU, and a mixture of PU and PETG, with different degrees of crystallinity which affect the transparency of each aligner. In particular, the PETG-based materials reveal the highest value of short-range order and the highest properties in terms of transparency in the visible range. After 14 days of immersion into red wine and coffee, PETG and PU-based aligners reveal a perceivable change in color (NBS values from 1.5 to 3), corresponding to a loss of transparency due to the deposition of impurities on the surface. These results are particularly marked for Invisalign, showing changes towards other colors (NBS up to 35), probably due to the thermoforming process which led to the formation of a wrinkled surface entrapping the impurities.

Ceramics ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 235-245
Author(s):  
Daniele dos Santos ◽  
Emily da Silva ◽  
Juliani Mendonça ◽  
Denis Cetrangolo ◽  
Fernanda Caxias ◽  
...  

This study aimed to evaluate the effect of a bleaching agent on the color of extrinsically pigmented indirect composite resins. Samples of five resins (Adoro, Resilab, Cristobal, Sinfony, Epricord) were manufactured and divided into five groups: red wine, coffee, orange juice, Coca-Cola, and artificial saliva (control). The stained samples were immersed in a 38% hydrogen peroxide solution for 30 min per week, over three weeks. Color readings were performed at the initial state (L0), after 21 days of dye immersion (ΔE1, L1), and after 7 (ΔE2, L2), 14 (ΔE3, L3), and 21 days (ΔE4, L4) of bleach immersion. Data were subjected to ANOVA and Tukey’s honestly significant difference (HSD) test (α = 0.05). The color alteration was greater in ΔE1, regardless of color solution, indicating extrinsic pigmentation. The Resilab group exhibited greater ΔE1 values than the other resins. The bleaching agent promoted bleaching action on the surfaces of the materials studied, removing the previously impregnated pigments.


2015 ◽  
Vol 1088 ◽  
pp. 519-525
Author(s):  
Hua Li Huang ◽  
Dan Feng ◽  
Hai Huan Gong ◽  
Ai Yang Song ◽  
Song Zhu

Heat-cured denture base resin is an important component in removable partial dentures and complete dentures, and has been widely used in the clinic. However, during long-term use, its appearance may be affected by varying degrees of color change, affecting the appearance and longevity of the dentures. In this study we examined the color changes and water absorption and solubility of dental base resins to investigate the color stability of four types of resin materials: New Century, Heraeus, Nissin and BASIS-HI. They were soaked in artificial saliva (as control), red wine, cola, coffee and tea separately at 37°C for 1, 4 or 12 weeks. Results are presented on which the color changes of dental base resin materials were associated with different denture base resins, soak solutions and storage times. We found that most of the dental resins became darker at prolonged immersion time. Heraeus resins showed more significant changes after soaking in red wine for 12 weeks, and its water absorption and solubility values were also greater than those of the other three types of resins. The color changes of New Century, Nissin and BASIS-HI soaked in the four solutions were relatively stable. The information obtained here will help optimize maintenance of dentures and also inform choice of denture materials.


Tetrahedron ◽  
2015 ◽  
Vol 71 (20) ◽  
pp. 3027-3031 ◽  
Author(s):  
Zsuzsanna Czibulya ◽  
Ibolya Horváth ◽  
László Kollár ◽  
Martin Pour Nikfardjam ◽  
Sándor Kunsági-Máté

2018 ◽  
Vol 20 (3) ◽  
pp. 167
Author(s):  
Ruchele Dias Nogueira ◽  
Rosa Maria Pereira Moisés Barbosa Andrade ◽  
Ailla Carla Rocha Acosta Lancellotti ◽  
Regina Guenka Palma-Dibb ◽  
Vinícius Rangel Geraldo-Martins

ResumoA resina composta é o material restaurador mais utilizado atualmente. Apesar de seu sucesso clínico, o material está sujeito a alterações em suas propriedades físicas, quando exposto ao meio bucal. O objetivo foi avaliar a influência da degradação química na estabilidade de cor e na rugosidade superficial de resinas micro-híbrida e nanoparticulada. Foram confeccionados 40 discos (6,0mm x 2,0mm) da resina composta micro-híbrida (Z250XT) e 40 da resina nanoparticulada (Z350XT). Após a análise da cor inicial e da rugosidade inicial, 10 discos de cada resina foram imersos em saliva artificial (Controle, pH=6,4), suco de laranja (pH= 3,4), refrigerante de limão (pH=2,9) e vinho tinto (pH=3,1), por 4 horas por dia (37ºC) durante 30 dias. Após, foram realizadas as leituras finais de cor e rugosidade. Os dados obtidos para a estabilidade de cor foram analisados pelo Teste de Kruskal-Wallis, seguido pelo Teste de Dunn (α=5%). Para a análise da rugosidade foi utilizado o Teste t para amostras pareadas (α=5%). O manchamento provocado pela saliva artificial, suco de laranja e refrigerante foi similar, mas foi estatisticamente diferente do manchamento produzido pelo vinho, em ambas as resinas testadas. O vinho produziu o mesmo grau de manchamento nas resinas micro-híbrida e nanoparticulada. Foi observado que o suco de laranja, o refrigerante e o vinho promoveram aumento da rugosidade superficial dos discos de resina. Diante disso, concluiu-se que o vinho alterou a cor de resinas compostas micro-híbrida e nanoparticulada, e que a rugosidade superficial dos discos de resina foi alterada por todas as bebidas utilizadas.Palavras chave: Resinas Compostas. Corantes. Cor.Abstract Composite resin is the most used restorative material. Despite its clinical success, it is susceptible to changes in its physical properties when exposed to the oral environment. The aim was to evaluate the influence of acidic beverages on the color stability and on the surface roughness of the nanofilled and micro hybrid composite. Forty discs (6.0mm x 2.0mm) of the micro hybrid composite (Z250XT) and 40 of the nanofilled composite (Z350XT) were manufactured. After the measurement of the initial color and the initial roughness, 10 discs of each composite were individually immersed in artificial saliva (control, pH = 6.4), orange juice (pH=3.4), lime soda (pH = 2.9) and red wine (pH = 3.1) during 4 hours per day at 37°C for 30 days. At the end of the experiment, the final analysis of color and surface roughness were performed. The data obtained for the color stability were analyzed by Kruskal-Wallis and Dunn’s test (α= 5%). For the analysis of the surface roughness, the t test for related samples was used (α= 5%). The color changes promoted by artificial saliva, orange juice and soda were similar, but they were statistically different from staining produced by wine, in both tested composites. Wine produced the same degree of staining in both composites. Orange juice, soda and red wine increased the surface roughness of the composite discs. It was concluded that red wine significantly changes the color of micro hybrid and nanofilled composites. Furthermore, all beverages increased the surface roughness of the composites tested in the study herein.Keywords: Composite Resins. Coloring Agents. Color.


2013 ◽  
Vol 804 ◽  
pp. 141-145
Author(s):  
Xiu Lan Chen ◽  
Huang Qin Chen

The purpose of this study was to investigate the effect of liquid polishing system (BisCover) on color stability of the bleached enamel upon exposure to a staining agent-red wine. Forty specimens were prepared. They were divided into 2 groups and different procedures, including only bleaching with Opalescence PF (PF) or Opalescence regular (R) gels, and application of BisCover after blaeching (PF-B, R-B) were used. Unbleached specimens were served as control groups (control-1 and control-2). The specimens were stored for 48 h in red wine. The color of all specimens was measured before and after exposure with a spectrophotometer, and total color change (ΔE*) were calculated. The data were analyzed with a one-way ANOVA and the means were compared by Tukeys post hoc analysis (α=0.05). PF-B and R-B groups demonstrated significantly less color change than PF and R groups. the control-1 and control-2 groups had the least color change. No significant difference were observed between PF and R group. BisCover improved the color stability of bleached enamel in red wine.


2015 ◽  
Vol 18 (1) ◽  
pp. 60 ◽  
Author(s):  
Mateus Guimaraes Lage Reggiani ◽  
Fernanda Alves Feitosa ◽  
Rodrigo Máximo De Araújo

<p><strong>Objective: </strong>Changes in color of artificial teeth mainly occur due to ingestion of beverages and use of products for cleaning and disinfection. The more aggressive solutions must be identified and the patient provided with explanations in order to avoid or reduce the frequency of their use, to a higher longevity of the denture. The purpose of this study was to evaluate the changes in color of artificial teeth before and after immersion in beverages and disinfectants. <strong>Material and Methods: </strong>96 artificial resin teeth were randomly divided into 8 groups. Each group was immersed for 10 min into a test solution (coffee, lemon juice, chlorhexidine gluconate, red wine, cola-based soft drink, vinegar or antiseptic with and without alcohol) and then the specimens were stored in artificial saliva for 23 h and 50 min, completing a period of 24 h. This procedure was performed for 14 consecutive days and after this period the second color measurement was made.The data obtained with the spectrophotometer using the CIEL*a*b* system were statistically analyzed using ANOVA non parametric, Kruskal-Walis and the Dunn test. <strong>Results: </strong>There were found differences in color variation for each experimental group after the challenge. statistically significant differences were found between the coffee, red wine and lemon juice groups. <strong>Conclusion: </strong>All the substances changed the color of artificial teeth; coffee was the substance that caused most staining of artificial teeth, altering color and luminosity; the oral antiseptics with and without alcohol promoted whitening of the artificial teeth.</p><p class="western" align="justify"><span style="font-family: Arial, serif;"><strong>Keywords: </strong></span><span style="font-family: Arial, serif;"><span lang="en-US">Artificial tooth; Denture; Oral rehabilitation; Staining.</span></span></p>


2020 ◽  
Vol 49 ◽  
Author(s):  
Luís Felipe ESPÍNDOLA-CASTRO ◽  
Pamella Robertha Rosselinne Paixão CELERINO ◽  
Tácyla Alves do NASCIMENTO ◽  
Gabriela Queiroz de Melo MONTEIRO ◽  
Tereza Cristina CORREIA

Abstract Introduction One of the most commonly used corrective methods for staining teeth is tooth bleaching. However, subclinical alterations may occur in the micromorphology of dental tissues during the bleaching procedure, such as increases in porosity and surface roughness. Consequently, dental enamel may become more permeable and susceptible to staining. Objective To evaluate the influence of tooth polishing after in-office bleaching treatment on color stability. Material and method Thirty-three extracted human molars were used. The teeth were cut in the mesiodistal direction to obtain two samples per tooth (total of 66). The samples were randomly divided into six groups (n=11). Before and after the bleaching treatment, the lightness of the samples and change in lightness (∆L) were determined with a digital spectrophotometer (Easy Shade). The samples were bleached with 35% hydrogen peroxide (three sessions weekly). Three groups were submitted to polishing with felt discs and polishing paste after each session. To simulate the oral conditions during the consumption of colored beverages, the samples were submitted to alternating cycles of immersion in staining solutions (coffee, red wine, and Coca Cola). Result Polishing resulted in an increase of mean lightness of 4.49 in the red wine group, 2.73 in the coffee group, and 4.08 in the cola group. The difference was significant in the red wine group (p<0.022), but not in the coffee or cola group. Conclusion Polishing after in-office bleaching using felt discs and polishing paste can reduce the degree of pigment impregnation in patient with red wine rich diet.


2017 ◽  
Vol 11 (02) ◽  
pp. 149-156 ◽  
Author(s):  
Matteo Ceci ◽  
Matteo Viola ◽  
Davide Rattalino ◽  
Riccardo Beltrami ◽  
Marco Colombo ◽  
...  

ABSTRACT Objective: A crucial property of esthetic restorative materials is their long-term color stability. The aim of this in vitro study was to evaluate the color stability of esthetic restorative materials (one microfilled flowable composite, one nanofilled composite, one nanoybrid composite, one microfilled composite, and one nanoybrid ormocer-based composite) after surface roughening with cola and exposure to different staining solutions (coffee and red wine).Materials and Methods: All materials were polymerized into silicone rubber rings (2 mm × 6 mm × 8 mm) to obtain 150 specimens identical in size. Seventy-five specimens of Group A were first exposed to cola for 24 h, and then samples were immersed in coffee or red wine over a 28-day test period. A colorimetric evaluation, according to the CIE L*a*b* system, was performed at 7, 14, 21, 28 days. Shapiro–Wilk test and Kruskal–Wallis analysis of variance were applied to assess significant differences among restorative materials. Means were compared with Scheffe's multiple comparison test at the 0.05 level of significance.Results: Specimens of Group A showed higher variations when compared with Group B's specimens (P < 0.05). After 28 days, the immersion protocols caused a clinically perceivable color change for all materials tested (P < 0.05). CeramX Universal and Admira Fusion showed the lowest ΔE variations (P < 0.05). Conclusions: Staining beverages caused significant discolorations for all the materials tested. The first exposure to cola enhanced the subsequent staining with coffee or red wine. Nanohybrid composites reported the lowest color variations.


2013 ◽  
Vol 804 ◽  
pp. 57-61
Author(s):  
Huang Qin Chen ◽  
Bin Huang

The purpose of this study was to investigate the effect of polyanionsodium tripolyphosphate (STP) on color stability of the bleached enamel upon exposure to a staining agent-red wine. Thirty specimens were prepared and bleached with 35% hydrogen peroxide (HP). Then, they were divided into three groups and immersed in different experiment solutions, including distilled and deionized water (DDW, negative control), 2% STP (PH 9.0) and 1000 ppm NaF aq. (positive control), before and after red wine stain challenge, 3 times per day. The color of all specimens was measured before and after exposure to red wine with a spectrophotometer, and total color change (ΔE*) were calculated. The data were analyzed with a one-way ANOVA and the means were compared by Tukeys post hoc analysis (α=0.05). STP treatment group demonstrated significantly less color change than DDW and NaF groups (p<0.05). No significant difference was observed between DDW and NaF group. It can be concluded that the staining susceptibility of bleached enamel decreased after application of polyanion sodium tripolyphosphate.


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