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.

Comportamiento cromático de resinas acrílicas y bisacrílicas para restauraciones provisionales / Chromatic behavior of acrylic and bisacrylic resins used for provisional restorations

Introducción: Las prótesis provisionales son restauraciones usadas en prótesis fijas durante un tiempo, hasta la cementación de la prótesis definitiva. Uno de los problemas que presentan este tipo de restauraciones es el cambio de color, que afecta a la estética y, en consecuencia, produce sensación de desagrado en los pacientes. Objetivo: Evaluar, para restauraciones provisionales, con y sin el pulido final de la superficie, la estabilidad del color de dos resinas al ser sumergidas en café. Métodos: Estudio experimental in vitro, realizado en el Laboratorio de Prótesis de la Facultad de Odontología de la Universidad Nacional del Nordeste, Corrientes-Argentina, 2019. Se comparó una resina acrílica (Duralay®) con una bisacrílica (ProtempIV 3M®) para restauraciones provisionales. Se elaboraron 40 discos de resinas a partir de moldes metálicos de 25 mm de diámetro y 2 mm de espesor. Se utilizaron 20 discos para cada tipo de resina, de ellos, 10 pulidos y 10 sin pulir. Las muestras fueron almacenadas en agua destilada en estufa a 37 °C durante 24 h para hidratarlos. Luego se procedió a la toma del color. Con posterioridad, cada grupo se sumergió en café, manteniéndolos en estufa a 37 °C durante 24 h más. Seguidamente, se realizó la segunda toma del color. Se utilizó el colorímetro Kónica Minolta®, determinando la diferencia total de color ΔE. Para el análisis estadístico se utilizó ANOVA una vía y test de Tukey para identificar la diferencia entre grupos. Resultados: Se observó en el grupo de resina acrílica pulida una diferencia ΔE = 0,82 ± DS = 0,22 y de ΔE = 3,86 ± DS = 0,30 sin pulido. En el grupo de resina bisacrílica pulido se obtuvo ΔE = 4,84 ± DS = 0,25 y, para el no pulido, ΔE = 5,85 ± DS = 0,29. Conclusiones: Se comprobaron diferencias significativas en la estabilidad del color de ambas resinas. La resina bisacrílica fue la menos estable, independientemente del pulido(AU)

Introduction: Provisional prosthesis are restorations used in fixed prostheses for a while, until the definitive prosthesis is cemented. One of the problems posed by this type of restoration is the change in color, which affects esthetics and therefore creates a feeling of displeasure in patients. Objective: Evaluate, in the case of provisional restorations with and without final surface polish, the color stability of two resins when soaked in coffee. Methods: An in vitro experimental study was conducted in the Prosthesis Laboratory at the Dental School of the National University of the Northeast in Corrientes, Argentina, in the year 2019. A comparison was made of an acrylic resin (Duralay®) versus a bisacrylic resin (ProtempIV 3M®) for provisional restorations. Forty resin disks were made from metal molds 2 mm thick and 25 mm in diameter. Twenty disks were used for each type of resin, of which 10 were polished and 10 were not. The samples were stored in distilled water in a stove at 37ºC for 24 h to hydrate them. Color measurements were then taken. Next, each group was soaked in coffee and kept in the stove at 37ºC for another 24 h. A second color measurement was then taken. A Konica Minolta® colorimeter was used to determine total color difference ΔE. Statistical analysis was based on one-way ANOVA and Tukey's test was used to identify the difference between the groups. Results: In the polished acrylic resin group a difference was found of ΔE = 0.82 ± SD = 0.22, whereas in the non-polish group the difference was ΔE = 3.86 ± SD = 0.30. In the polished bisacrylic resin group the difference was ΔE = 4.84 ± SD = 0.25, whereas in the non-polish group the difference was ΔE = 5.85 ± SD = 0.29. Conclusions: Significant differences were found in the color stability of both resins. The bisacrylic resin was the least stable, regardless of polish(AU)

Study of masking ability of laminate veneers for discolored teeth / 北京大学学报(医学版)

OBJECTIVE@#To select the most effective method among different masking treatments, such as different thickness and transparence, tissue surface's opaque coating, and opaque resin cement to restore discolored teeth esthetically by porcelain veneer.@*METHODS@#Four extracted intact maxillary central incisors were prepared for porcelain veneer restoration and each three heat pressed porcelain veneers from three thicknesses (0.8 mm, 1.0 mm, 1.2 mm) and two transparency(high transparence, HT and low transparence, LT))in Vita shade A2 were fabricated for each tooth, in total of 72 pieces. The surfaces of three prepared teeth were then painted to mimic situations of severe dental fluorosis, severe tetracycline teeth, and necrotic teeth. Each of the veneers was temporarily cemented to the corresponding tooth surface using try-in cements with three different colors (transparent, opaque, and yellow), then used the shade guide (3D master) and electronic colorimeter (easy shade) to record the shade of each porcelain veneer through hue, lightness, and chroma reading. After that, high-transparence porcelain veneers in thickness of 0.8 mm was fused with a layer of opaque porcelain in tissue surface, and were shade matched again after cementation. Statistic treatments were performed to analyze the difference in each masking method.@*RESULTS@#For each 0.2 mm increase in the veneer thickness of porcelain, the average lightness was reduced by 1 unit, while the chroma was not changed which was independent of the type of the resin cements. When the thickness of the porcelain veneer was decreased to 0.8 mm, the opacity effect was not remarkable even if a low-transparence porcelain veneer was used. Transparent and yellow resin cements had poor opaque performance, while opaque resin cement could reduce the lightness by 2 units and the chroma was also reduced. The opaque layer of the tissue surface could be applied uniformly, and the lightness and chroma could be reduced to Vita 2M1 to 2M1.5 levels regardless of the color of resin cements, which suggested a stable opacity effect for different discolored teeth in this study.@*CONCLUSION@#For porcelain veneer restoration of discolored teeth, thickened veneers are the most effective means to display a natural transmittance and color. Tissue surface's opacity coatings and opaque resin cements can also be used to reduce grayscale and increase lightness.

Intra- and inter-brand color differences of denture teeth under different illuminations

Abstract Debonding, staining and wear are usually the reasons for denture teeth replacement by new ones from same or different brands. Objective This study investigates the possible differences in color of denture teeth of the same or different brands under different illuminations, since their metameric behavior in color under specific illumination may become unacceptable. Methodology For the purpose of this study, 10 denture teeth (#11), shade A3, of 4 different brands were selected (Creopal/KlemaDental Pro, Executive/DeguDent, Cosmo HXL/DeguDent, Ivostar/Ivoclar-Vivadent). Teeth stabilized in white silicone mold and the CIELAB color coordinates of their labial surface under 3 different illumination lights (D65, F2, A) were recorded, using a portable colorimeter (FRU/WR-18, Wave Inc). ΔE*ab values of all possible pairs of teeth of the same brand (n=45) or pair combinations of different brands (n=100) under each illumination light, in a dry and wet state were calculated. Data were analyzed statistically using 3-way ANOVA, Friedman's and Wilcoxon's tests at a significance level of α=0.05. Results The results showed that brand type affected significantly L*, a* and b* coordinates (p<0.0001), illumination a* and b* coordinates (p<0.0001), but none of them was affected by the hydration state of teeth (p>0.05). Intra-brand color differences ranged between 0.21-0.78ΔΕ* units with significant differences among brands (p<0.0001), among illumination lights (p<0.0001) and between hydration states (p=0.0001). Inter-brand differences ranged between 2.29-6.29ΔΕ* units with significant differences among pairs of brands (p<0.0001), illumination lights (p<0.0001) and hydration states (p<0.0001). Conclusions Differences were found between and within brands under D65 illumination which increased under F2 or A illumination affected by brand type and hydration status. Executive was the most stable brand than the others under different illuminations or wet states and for this reason its difference from other brands is the lowest. In clinical practice, there should be no blending of teeth of different brands but if we must, we should select those that are more stable under different illuminations

Color Change of Different Dual-Cure Resin Cements After Thermocycling / Cambio de color de diferentes cementos de resina de curado doble después del termociclaje

ABSTRACT The purpose of this study is to evaluate the effect of thermocycling on the color change of the amine-free dual-cure resin cements. IPS e.max CAD blocs were cut into specimens of 1 mm thickness (N=28) and cemented with one of the 4 different amine-free dual-cure resin cements (NX3 Nexus [NX], Kerr Dental; Variolink Esthetic DC [VE], Ivoclar Vivadent; Panavia V5 [PV], Kuraray Dental; G-CEM Linkforce [GC], GC Corporation) (n=7). A spectrophotometer was used for color measurements. Specimens were subjected to thermocycling (5°C and 55°C; 5000 and 10000 cycles). Normality of data distribution was tested by using the Kolmogorov-Smirnov test. Statistical analysis was performed using a two-way analysis of variance (ANOVA) and Tukey's multiple comparison tests at a significance level of p<0.05.∆E values were significantly influenced by the resin cements and the cycle periods (p<0.05). There were no significant differences between NX and VE groups after 5000 thermocycling, however after 10000 thermocycling VE group showed higher ∆E1 values than NX group (p>0.05). There were no statistically significant differences between the ∆E0 and ∆E1 values of the GC group, however the other groups were affected after 10000 thermocycling (p>0.05). Amine-free resin cements used for cementation showed color change after thermocycling except GC group. All resin cements were showed clinically acceptable color change after thermocycling (∆E<3.5).

RESUMEN El propósito de este estudio es evaluar el efecto del termociclaje en el cambio de color de los cementos de resina de doble curado sin aminas. Los bloques IPS e.max CAD se cortaron en muestras de 1 mm de espesor (N=28) y se cementaron con uno de los 4 diferentes cementos de resina de curado doble libres de aminas (NX3 Nexus [NX], Kerr Dental; Variolink Esthetic DC [VE], Ivoclar Vivadent; Panavia V5 [PV], Kuraray Dental; G-CEM Linkforce [GC], GC Corporation) (n=7). Se usó un espectrofotómetro para las mediciones de color. Las muestras se sometieron a termociclaje (5°C y 55°C; 5000 y 10000 ciclos). La normalidad de la distribución de datos se probó utilizando la prueba de Kolmogorov-Smirnov. El análisis estadístico se realizó mediante un análisis de varianza de dos vías (ANOVA) y las pruebas de comparación múltiple de Tukey a un nivel de significación de p<0.05. Los valores de ∆E fueron significativamente influenciados por los cementos de resina y los períodos de ciclo (p<0.05). No hubo diferencias significativas entre los grupos NX y VE después de 5000 termociclos, sin embargo, después de 10000, el grupo VE mostró valores ∆E1 mayores que el grupo NX (p>0.05). No hubo diferencias estadísticamente significativas entre los valoresn∆E0 y ∆E1 del grupo GC, no obstante, los otros grupos se vieron afectados después de 10000 termociclos (p>0.05). Cementos de resina libres de aminas. utilizados para la cementación mostró cambio de color después del termociclaje, excepto el grupo GC. Todos los cementos de resina mostraron un cambio de color clínicamente aceptable después del termociclaje (∆E<3.5).

Influência do polimento e tipo de solução extrínseca na pigmentação de restaurações de resina composta / Influence of the dental polishing and type of extrinsic solution in the pigmentation of composite resin restorations

Objetivo: avaliar a pigmentação de restaurações de resina composta (RC) submetidas a diferentes métodos de polimento. Materiais e método: foram realizadas restaurações de RC classe V em 80 dentes bovinos, corpos de prova, divididos em dois grupos experimentais: G1, polimento com Ultra-Gloss, e G2, polimento com um sistema que utiliza uma ponta siliconada impregnada com abrasivo, Enhance. Após, todos os grupos experimentais foram submetidos a soluções pigmentantes de café, chimarrão e refrigerante, 2 vezes ao dia, por 5 minutos, num período de 15 dias. Os corpos de prova foram analisados pela coloração da RC através de um colorímetro utilizando o sistema CIE-Lab. Aplicou-se a análise de variância seguida do método de comparação múltipla de Tukey, quando observada diferença significativa entre os corpos de prova. Resultados: os resultados mostraram que houve diferença estatística nos valores de médios (valor-p < 0,05), sugerindo o café com variação mais elevada; também para as variações entre a condição experimental (valor-p < 0,05), com exceção de delta a (valor-p = 0,817). Conclusão: o tipo de método para polimento de restaurações em RC não apresenta associação significativa com a pigmentação do material, sendo que esta está relacionada com o tipo da solução corante e com o tempo de exposição do compósito às pigmentações. (AU)

Objective: to evaluate the pigmentation of composite resin restorations submitted to different polishing methods. Materials and method: Class V composite resin restorations were performed on 80 bovine teeth, specimens, and divided into two experimental groups: G1-polishing with Ultra-Gloss and G2-polishing with a system using a silicon tip impregnated with abrasive, Enhance. Afterwards, all the experimental groups were submitted to pigmenting solutions of coffee, chimarrão and refrigerante, 2 times a day, for 5 minutes, in a period of 15 days. The specimens were analyzed by coloring the composite resin using a colorimeter using the CIE-Lab system. The analysis of variance was applied followed by Tukey's multiple comparison method when a significant difference was observed between the test specimens. Results: The results showed that there was statistical difference in the mean values (p-value <0.05), suggesting coffee with the highest variation; (p-value <0.05), with the exception of delta a (p-value = 0.817). Conclusion: The type of method for polishing restorations in composite resin does not present a significant association with the pigmentation of the material, which is related to the type of the dye solution and the time of exposure of the composite to pigmentation. (AU)

Effect of different methods of hygiene on the color stability of extrinsically pigmented facial silicone

Evaluate the color stability of facial silicone pigmented extrinsically under the influence of the hygiene process. Methods: 160 samples were prepared and divided into 8 groups (n = 20) according to the pigmentation technique used: Group 1: Colorless silicone; Group 2: Pigmented exclusively with oil ink; Group 3: Pigmented with oil ink + opacifier; Group 4: Colorless, applying Prime; Group 5: Pigmented with oil ink covered with Prime; Group 6: Pigmented with oil ink + opacifier and covered with Prime; Group 7: Pigmented with oil ink diluted in Prime; Group 8: Pigmented with oil ink + opacifier diluted in Prime. Then the samples were distributed into two subgropus (n=10): 1: neutral soap and 2: 1% hypochlorite solution. The color readings occurred in the initial period and 60 days after the hygiene procedures. For this, it was used a spectrophotometer reflection and CIE-Lab program. The data was tabulated and submitted to analysis of variance (ANOVA) followed by Tukey test (p <0.05). Results: The groups of samples disinfected with soap showed significantly lower color change values than those presented by the samples disinfected with hypochlorite. The best results were presented by the group of samples pigmented with oil ink diluted in prime and sanitized with neutral soap (ΔE=1.21, without opacifier and ΔE=0.82, with opacifier). Conclusions: The association of oil ink diluted in prime and hygiene technique with soap promotes the lower color change of facial silicone pigmented extrinsically

Inorganic filler content of resin-based luting agents and the color of ceramic veneers

Abstract The influence of inorganic filler content of resin-based luting agents (RBLAs) on color change (ΔE00), CIEL*a*b* (individual color coordinates), and translucency parameters (TP) of simulated ceramic laminate veneer (CLV) was investigated. RBLAs with low, intermediate, and high inorganic filler content (55%, 65%, and 75% mass fractions, respectively) were prepared. Feldspar ceramic (Vitablocs Mark II) specimens (1.2 mm × 0.8 mm, A1C shade) were bonded to simulated composite resin substrates (1.6 mm × 1.2 mm, A2D shade) using three experimental and a commercial (RelyX Veneer) RBLA (translucent shade). The ΔE00 was calculated by CIEDE2000 color difference metric under three conditions (before, immediately after, and 24 h after luting). The TP was calculated using CIEL*a*b* color coordinates measured over white and black backgrounds. Surface morphology of the RBLAs was analyzed. One-way and two-way analyses of variance with a post-hoc Tukey's test were used respectively to calculate TP, CIEL*a*b* coordinates, and ΔE00 (α= 0.05). Overall, the tested RBLAs presented clinically visible ∆E00 values under the three conditions evaluated. For all RBLAs, higher ∆E00 values were observed between measurements obtained before and immediately after luting. Different inorganic filler content did not significantly increase the opacity of the ceramic-luting agents-resin composite set. The variation in inorganic filler content did not influence significantly the TP of simulated CLV; although all of the experimental RBLAs tested yielded ∆E00 above the perceptibility threshold. The L*, a*, and b* individual color coordinates were cementation-dependent.

Long-term microwaving of denture base materials: effects on dimensional, color and translucency stability

Abstract While the combined effect of microwave irradiation with cleansing solutions on denture base materials has been investigated, the effects of only using microwave irradiation and, more importantly, in a long-term basis, was not studied yet. Objective The purpose of this study was to evaluate the effect of a long-term repeated microwaving on the dimensional, color and translucency stability of acrylic and polyamide denture base materials. Material and Methods Thirty two specimens (32 mm x 10 mm x 2.5 mm) from polyamide (Valplast) and PMMA (Vertex Rapid Simplified) denture base materials were made. Eight specimens from each material were immersed in distilled water (control) and 8 were subjected to microwave exposure at 450 W for 3 minutes for a period simulating 224 days of daily disinfection. Linear dimension, color change (ΔE*) and translucency parameter (TP) were measured at baseline and after certain intervals up to 224 cycles of immersion, using a digital calliper and a portable colorimeter. The results were analysed using two-way repeated measures ANOVA to estimate possible differences among predetermined cycles and material type. Regression analysis was also performed to estimate the trend of changes with time. Statistical evaluations performed at a significance level of 5%. Results Data analysis showed significant changes in length at baseline with an increasing number of cycles (p<0.05) and a significant interaction of cycle-material (p<0.001). The ΔΕ* parameter was significantly higher with a higher number of cycles (p<0.001), but it did not vary between materials (p>0.05). TP decreased similarly in both materials following microwave action but in a significantly higher level for Valplast (p<0.001). Conclusions The results indicated that long-term repeated microwaving affects linear dimensional, color and translucency changes of both materials. Differences between PMMA and polyamide material were noted only in dimension and translucency changes.

Comparative study on the shade matching performance of dental students under D55 and D65 light sources conditions / 华西口腔医学杂志

OBJECTIVE@#This study aimed to compare the effect of D55 and D65 light sources on the visual colorimetry performance of dental students by using a homemade light-source shelf.@*METHODS@#Two Vitapan 3D-Master shade guides were randomly selected. One set was used as shade guides. Ten commonly used shade tabs of 2L2.5, 2M2, 2R2.5, 3M2, 3R2.5, 3L1.5, 3R1.5, 3L2.5, 4R1.5, and 4L1.5 were selected from the other set with covered value marks and numbered from 1 to 10. After the colorimetric training, 49 undergraduate dental students were randomly divided into two groups. Each student randomly selected two of the 10 shade tabs, and the colors were subsequently matched under D65 and D55 light sources from a distance of approximately 40 cm. The average color difference (ΔE) between the color selected by each participant and the actual color of shade tabs was calculated. Paired t test was used for statistical analysis.@*RESULTS@#The ΔE values between the color selected by each participant and the actual color of the shade tabs under the D55 light source varied from 0 to 6.540. The average value was 2.501. The ΔE values between the color selected by each participant and the actual color of the shade tabs under the D65 light source varied from 0 to 6.610. The average value was 2.530. No statistically significant difference was observed between the results under the two light sources (P=0.921).@*CONCLUSIONS@#Both D55 and D65 daylight lamps can be used for daily dental colorimetry. These two different color temperatures showed no significant difference.

Comparison of the color difference between teeth underwent cold light whitening and two kinds of shade guides / 北京大学学报(医学版)

OBJECTIVE@#To investigate which shade guide, Vitapan Classical or Vita Bleachedguide 3DMaster, is better matched with the color of teeth in judging whitening effect, by comparing the color difference between shade tabs and corresponding teeth underwent cold light tooth whitening.@*METHODS@#A total of 60 patients underwent Beyond cold light tooth whitening from May 2014 to April 2016. The patients were divided into two experimental groups according to the shade guide used. Vitapan Classical shade guide was used to judge whitening effect in one group, and Vita Bleachedguide 3DMaster shade guide was used in another. Shade matching was carried out before and after whitening in both the two groups, and the results were recorded by digital photographs. Shade matching procedures were carried out by two doctors independently. If they chose the same tab, it would be seen as the shade matching result; While if they chose different tabs, another doctor would be invited to make a decision. Photographs were taken in preset conditions: intraoral photos of the full dentition in the front, and the proportion of shooting was 1:3; aperture was F22; shutter speed was 1/200; intensity of flash was M/8; ISO value was 200. The photographs were analyzed by Photoshop software. Chromatic values were measured, and color difference values were calculated. Measuring of chromatic values was carried out by three doctors independently, and all the photos were measured twice by each doctor. Six measure results of each photo were recorded, and the maximum and the minimum were excluded, then the mean was seen as the final result. The color difference values were compared by independent-sample t test. Besides, changes of shade tabs after whitening in the two groups were recorded.@*RESULTS@#Color difference value was 5.06±1.71 in Vitapan Classical group, and 3.39±1.36 in Vita Bleachedguide 3D-Master group. There was statistically significant difference between the two groups (t=4.68,P<0.001). Change of shade tabs was 3.63±1.75 in Vitapan Classical group, and 2.23±1.01 in Vita Bleachedguide 3DMaster group.@*CONCLUSION@#Vita Bleachedguide 3D-Master is better matched with the color of teeth, so it is preferred in judging the effect of cold light tooth whitening.

Crown discoloration promoted by materials used in regenerative endodontic procedures and effect of dental bleaching: spectrophotometric analysis

Abstract Regenerative endodontic procedure (REP) has been proposed as a new approach to treat immature permanent teeth. However, materials used in REP for root canal disinfection or cervical sealing may induce tooth discoloration. Objectives To assess tooth crown’s color after intracanal treatment with triple antibiotic paste (TAP) or calcium hydroxide (CH); cervical sealing with glass ionomer cement (GIC) or mineral trioxide aggregate (MTA); and bleaching with carbamide peroxide. Material and Methods After pulp removal and color spectrophotometer measurement, 50 bovine incisors were divided into 4 experimental groups and one control (untreated). Experiments were performed in phases (Ph). Ph1: TAP (ciprofloxacin, metronidazole, minocycline), TAPM (ciprofloxacin, metronidazole, amoxicillin), DAP (ciprofloxacin, metronidazole), or CH treatment groups. After 1 and 3 days (d); 1, 2, 3 weeks (w); and 1, 2, 3 and 4 months (m), color was measured and medications were removed. Ph2: GIC or MTA cervical sealing, each using half of the specimens from each group. Color was assessed after 1d, 3d; 1w, 2w, 3w; 1m and 2m. Ph3: Two bleaching sessions, each followed by color measurement. Data were analyzed with ANOVA and post-hoc Holm-Sidak method. Results Ph1: Specimens of TAP group presented higher color alteration (ΔE) mean than those of TAPM group. No significant difference was found among TAP or TAPM and CH, DAP or Control groups. Ph2: cervical sealing materials showed no influence on color alteration. Ph3: Different ΔE means (from different groups), prior to bleaching, became equivalent after one bleaching session. Conclusions TAP induces higher color alteration than TAPM; color alteration increases over time; cervical sealing material has no influence on color alteration; and, dental bleaching was able to recover, at least partially, the tooth crown’s color.

Avaliação da influência do processo de confecção e da espessura da cerâmica, do substrato e do cimento na cor final da cerâmica de dissilicato de lítio, após o envelhecimento artificial acelerado / Influence of the manufacturing process and thickness of the ceramic, substrate and cement on the final color of the lithium disilicate ceramic after accelerated artificial aging

O propósito deste trabalho foi avaliar, in-vitro, a alteração de cor da cerâmica de dissilicato de lítio, após o envelhecimento artificial acelerado (EAA), variando-se os seguintes aspectos: processo de confecção (cerâmica monolítica e com infraestrutura coberta por cerâmica de revestimento), espessuras de 1,5 e 2,0mm e substratos de resina e liga metálica, com e sem cimento. Para isso foram confeccionadas 40 pastilhas de cerâmica IPS e.max Press, que foram divididas em 2 grupos (n=20): LT (cerâmica de baixa translucidez na cor A2) e HO (cerâmica de alta opacidade). Neste grupo as pastilhas foram confeccionadas com 0,5mm de espessura e, posteriormente, revestidas com a cerâmica IPS e.max Ceram na cor A2 e com espessuras de 1,0 e 1,5mm. Foram utilizados substratos em resina composta (n=20) e em liga metálica (cobre-alumínio) (n=20). Para a cimentação foi utilizado o cimento de polimerização dual Variolink II, na cor translúcida. A leitura da cor foi realizada em um espectrofotômetro (Minolta CM2600d), equipado com fonte de luz padrão D65 (luz do dia). A cor determinada no aparelho é expressa em coordenadas CIE L* a* b* e os valores correspondentes foram utilizados para calcular o E. Foram feitas as seguintes comparações: discos de cerâmica antes do EAA vs discos de cerâmica cimentadas sobre os substratos antes do EAA; discos de cerâmica cimentadas sobre os substratos antes do EAA vs discos de cerâmica cimentadas sobre os substratos após o EAA; discos de cerâmica antes do EAA vs discos de cerâmica cimentadas sobre os substratos após o EAA; discos de cerâmica antes do EAA vs discos de cerâmica após o EAA. Os dados foram submetidos a análise estatística (ANOVA) a 3 critérios e (ANOVA) a 2 critérios e testes de Tukey, p<0,05). Os resultados mostraram que: 1. os grupos somente de discos de cerâmica vs discos de cerâmica com 1,5 e 2,0mm de espessuras, cimentadas em substratos de resina e liga metálica, antes do EAA. O menor valor encontrado de E (E=3,6) foi com o grupo de discos da cerâmica HOA2 com 2mm de espessura cimentados em substrato de metal, seguido pelo grupo da mesma cerâmica com 1,5mm de espessura cimentada em substrato de resina. O maior valor encontrado (E=10,0) foi com os discos de cerâmica LTA2 com 1,5 e 2mm de espessuras e cimentados em substrato de metal; 2. os grupos com discos de cerâmicas com 1,5 e 2,0mm de espessuras e cimentados em substratos de resina e liga metálica antes do EAA vs o mesmo grupo após EAA. Os grupos de discos com a cerâmica HOA2 com 2mm de espessura cimentados em substrato de metal teve menor alteração de cor (E=1,1) e a maior alteração de cor ocorreu com o grupo da cerâmica LTA2 com 2mm de espessura cimentada em substrato de metal (E=2,1); 3. os grupos somente com discos de cerâmica antes do EAA vs grupos de cerâmicas com discos de 1,5 e 2,0mm de espessuras e cimentados em substratos de resina e liga metálica após o EAA. O menor valor encontrado (E=3,7) foi com a cerâmica HOA2 com revestimento e 2mm de espessura cimentada em substrato de metal. O maior valor encontrado (E=10,0) foi o da cerâmica LTA2 com 1,5 e 2mm de espessuras cimentadas em substrato de metal; 4. os grupos discos de cerâmica, antes e após o processo de EAA O grupo que teve menor alteração de cor foi o da cerâmica HOA2 com 1,5mm (E=0,6). O grupo que teve maior alteração de cor foi o da cerâmica LTA2 com 2mm (E=2,2). Concluiu-se que o EAA causou alteração na cor final das cerâmicas de dissilicato de lítio, levando-se em conta as variáveis pesquisadas.(AU)

The purpose of this in vitro study was to evaluate the color changing of the lithium disilicate ceramic discs after accelerated artificial aging (AAA) varying the following aspects: manufacturing process (monolithic ceramic and infrastructure with ceramic covering), thickness of the ceramic (1.5 and 2.0 mm) and abutment substrate (composite resin and alloy), with and without cement. Forty ceramic discs were fabricated with ceramic IPS e.max Press and divided into two groups (n = 20): LT (low translucency, shade A2) and HO (high opacity). In the HO group, the discs were fabricated with a thickness of 0.5 mm of the IPS e.max Ceram combined with a thickness of 1 or 1.5mm of veneering ceramic, shade A2. The abutments substrates were fabricated with composite resin (n = 20) and metallic alloy (n = 20). The resin cement used was Variolink II translucent color. Color was measured with a spectrophotometer and expressed in CIE L * a * b * coordinates. Color differences (E) were calculated. The data were analyzed with ANOVA and the Tukey HSD test (p <0.05).The results showed that 1.in the groups of ceramic discs vs. ceramic discs with 1.5 and 2.0mm thickness, cemented on resin substrates and metal alloy, before AAA, the lowest value of E (E = 3,6) was obtained for HOA2 ceramic discs with 2mm thickness cemented in metal substrate, followed by ceramic discs with 1.5mm thickness cemented in substrate of resin. The highest value (E = 10.0) was observed for ceramic discs LTA2 with 1.5 and 2mm thickness and cemented in metal substrate; 2. In the groups with ceramic discs with 1.5 and 2.0mm thickness and cemented on resin and metal substrates prior to AAA vs the same group after AAA, the HOA2 ceramic discs with 2mm thickness cemented on a metal substrate had the smallest color change (E = 1,1) and the largest occurred for LTA2 with 2mm thickness and cemented in metallic substrate (E = 2.1); 3. In the groups of ceramic discs before AAA vs groups of ceramic with discs of 1.5 and 2.0mm of thickness and cemented on resin substrates and metal alloy after AAA, the lowest value (E = 3,7) was obtained for HOA2 veneering ceramic 2mm thickness cemented on a metal substrate. The highest value found (E = 10.0) was for LTA2 ceramic with 1.5 and 2mm thickness cemented on a metal substrate; 4. comparing the groups of ceramic discs before and after the AAA process, the lowest color change was obtained for HOA2 ceramic with 1.5mm (E = 0.6) and the greatest color change was fore LTA2 ceramic with 2mm (E = 2.2). It was concluded that the AAA caused alteration in the final color of the lithium disilicate ceramics, taking into account the variables studied.(AU)

Translucency and color stability of resin composite and dental adhesives as modeling liquids - A one-year evaluation

Abstract The aim of this study is to evaluate the influence of modeling liquids on the translucency and color shade of resin composites (RCs) after one year of storage. RC specimens were prepared using either a conventional insertion technique (control; without modeling liquid) or a restorative dental modeling insertion technique (RDMIT) with dental adhesives as modeling liquids (Scotchbond™ Multi-Purpose [SBMP; 3M ESPE] or Adper™ Single Bond 2 [SB; 3M ESPE]). The initial colors of the specimens were obtained with a digital spectrophotometer and the CIEL*a*b* color system, after which specimens were stored (37°C) in distilled water or red wine for 12 months. Color measurements were reassessed after 6 and 12 months of storage, and scanning electron microscopy was performed after 12 months. Translucency and color change (ΔE*) were calculated and analyzed using ANOVA and Tukey's test (α = 5%). RC samples prepared via RDMIT showed a translucency similar to that of control samples. ΔE* was also less intense for RCs containing SBMP than for RCs containing SB. Specimens stored in wine showed a clear pattern of degradation, especially in the control group, and surface degradation seemed to be less intense for specimens prepared with SBMP and SB than for specimens without. Specimens stored in water did not show clear evidence of surface degradation. RDMIT appears to be an interesting approach to reduce ΔE* in RCs over time without negative effects on the translucency of the material. However, the modeling liquid should feature a hydrophobic composition, similar to that used in the SBMP group, the achieve the best results.

Evaluation of phenyl-propanedione on yellowing and chemical-mechanical properties of experimental dental resin-based materials

ABSTRACT Objective To evaluate the influence of phenyl-propanedione on yellowing and chemical-mechanical properties of experimental resin-based materials photoactivated using different light curing units (LCUs). Material and Methods Experimental resin-based materials with the same organic matrix (60:40 wt% BisGMA:TEGDMA) were mechanically blended using a centrifugal mixing device. To this blend, different photoinitiator systems were added in equimolar concentrations with aliphatic amine doubled by wt%: 0.4 wt% CQ; 0.38 wt% PPD; or 0.2 wt% CQ and 0.19 wt% PPD. The degree of conversion (DC), flexural strength (FS), Young’s modulus (YM), Knoop hardness (KNH), crosslinking density (CLD), and yellowing (Y) were evaluated (n=10). All samples were light cured with the following LCUs: a halogen lamp (XL 2500), a monowave LED (Radii), or a polywave LED (Valo) with 16 J/cm2. The results were analysed by two-way ANOVA and Tukey’s test (α=0.05). Results No statistical differences were found between the different photoinitiator systems to KNH, CLS, FS, and YM properties (p≥0.05). PPD/CQ association showed the higher DC values compared with CQ and PPD isolated systems when photoactivated by a polywave LED (p≤0.05). Y values were highest for the CQ compared with the PPD systems (p≤0.05). Conclusion PPD isolated system promoted similar chemical and mechanical properties and less yellowing compared with the CQ isolated system, regardless of the LCU used.

Influence of resin cement shade on the color and translucency of ceramic veneers

ABSTRACT Objective This in vitro study evaluated the effect of two different shades of resin cement (RC- A1 and A3) layer on color change, translucency parameter (TP), and chroma of low (LT) and high (HT) translucent reinforced lithium disilicate ceramic laminates. Material and Methods One dual-cured RC (Variolink II, A1- and A3-shade, Ivoclar Vivadent) was applied to 1-mm thick ceramic discs to create thin RC films (100 µm thick) under the ceramics. The RC was exposed to light from a LED curing unit. Color change (ΔE) of ceramic discs was measured according to CIEL*a*b* system with a standard illuminant D65 in reflectance mode in a spectrophotometer, operating in the light range of 360-740 nm, equipped with an integrating sphere. The color difference between black (B) and white (W) background readings was used for TP analysis, while chroma was calculated by the formula C*ab=(a*2+b*2)½. ΔE of 3.3 was set as the threshold of clinically unacceptable. The results were evaluated by two-way ANOVA followed by Tukey's post hoc test. Results HT ceramics showed higher ΔE and higher TP than LT ceramics. A3-shade RC promoted higher ΔE than A1-shade cement, regardless of the ceramic translucency. No significant difference in TP was noted between ceramic discs with A1- and those with A3-shade cement. Ceramic with underlying RC showed lower TP than discs without RC. HT ceramics showed lower chroma than LT ceramics, regardless of the resin cement shade. The presence of A3-shade RC resulted in higher chroma than the presence of A1-shade RC. Conclusions Darker underlying RC layer promoted more pronounced changes in ceramic translucency, chroma, and shade of high translucent ceramic veneers. These differences may not be clinically differentiable.

Encía artificial en prótesis implantoasistida: indicaciones y aplicaciones clínicas / Artificial gingiva in implant-supported prosthesis: indications and clinical applications

En la rehabilitación odontológica integral actual, hay que evaluar los parámetros clínicos para una restauración sobre implantes dentales. El tratamiento del sector anterior de ambos maxilares en situaciones clínicas complejas, hace que el éxito sea difícil de alcanzar, inclusocuando todos los objetivos establecidos de diagnóstico y de planificación del tratamiento, sean respetados y puedan realizarse. El objetivo es imitar la apariencia de los dientes contiguos para simular la dentición natural, con un enfoque en la estética de los tejidos gingivales adyacentes a las restauraciones sobre implantes. En los casos en que el tejido óseo y la pérdida mucogingivales marcada y procedimientos quirúrgicos adicionales no son viables, se requerirá de tratamientos alternativos. Uno de ellos podría ser el uso de encía artificial para reconstruir las deficiencias de tejidos duros y blandos. Este artículo describe diferentes indicaciones y aplicaciones clínicas de la encía artificial en prótesis implanto asistida.

In the current comprehensive dental rehabilitation, clinical parameters for success restoration on dental implants must be evaluated.Treatment of both anterior maxillary and mandibular jaws in complex clinical situations makes success difficult to achieve, even when allestablished goals in diagnosis and treatment planning, are respected and can be made.The goal is to mimic the appearance of the adjacent teeth to simulate natural dentition, with a focus on the aesthetics of the gingival tissuesnext to implant restorations. In cases where the bone and mucogingival tissues loss are marked and additional surgical procedures shouldnot be viable, it will require alternative treatment options. One of them could be the use of artificial gingiva to rebuild the deficiencies ofhard and soft tissues.This article describes different indications and clinical applications in artificial gum assisted implant prosthesis.

Estudo da alteração dimensional linear dos elásticos ortodônticos em diferentes pigmentos e tempos de armazenamento / Study of linear dimensional change of orthodontic elastics in different pigments and storage times

O objetivo deste trabalho foi avaliar a alteração dimensional linear dos elásticos ortodônticos sendo submetidos ao tempo de armazenagem em saliva artificial a 37ºC durante o período imediato (T0), 24 horas (T24) e 30 dias (T30). Os grupos de elásticos foram divididos em cinco cores com dez (n=10) amostras por grupo: cinza (C); verde (V); preta (P); rosa (R) e transparentes (T), e marcas comerciais: Morelli (a); 3M Unitek (b); GAC (c). Utilizou-se a máquina de análise de dimensão (perfilômetro) da marca Mitutoyo, que avaliou a alteração de dimensão conforme as distâncias de extremidade dos elásticos e os fatores envolvidos como o tempo de armazenamento e a marca comercial. Em seguida, os dados foram analisados estatisticamente, obtendo os resultados e realizadas as tabelas, gráficos e as correlações lineares. Para esta avaliação foram utilizados os testes Anova e de Tukey (p < 0,01). Os resultados apontaram os seguintes valores: grupo V ­ t0:3,09 (± 0,24), t24:3,12 (± 0,36) e t30d:3,15 (± 0,22); grupo T ­ t0:3,07 (± 0,16), t24:3,10 (± 0,15), t30d:3,14 (± 0,10), grupo P ­ t0:3,13 (± 0,24), t24:,16 (± 0,19), t30d:3,18 (± 0,20); grupo R ­ t0:3,08 (± 0,25), t24:3,11 (± 0,14), t30d:3,13 (± 0,18); grupo C ­ t0:3,15 (± 0,31), t24h:3,18 (± 0,15) e t30d:3,19 (± 0,59). O grupo P apresentou diferença estatisticamente significante em relação aos demais. As marcas comerciais apresentaram pequenas alterações dimensionais, aceitáveis clinicamente de acordo com a literatura. Concluiu-se que os pigmentos, que determinam a cor específica dos elásticos, são fatores que interferem na propriedade deste material. O tempo de armazenamento é determinante e fundamental para avaliação do comportamento de estabilidade do material polimérico.

The objective of this study was to evaluate the linear dimensional change of orthodontic elastics submitted to the storage in artificial saliva 37ºC at baseline (T0), 24-hour (T24), and at 30-day (T30) periods. The groups (n=10) were divided into five colors: gray (C), green (V), black (P), pink (R), and clear (T) with the following brands: Morelli (a), 3m Unitek (b), and GAC (c). A profilometer (Mitutoyo) was used to analyze the dimensional changes. Next, means were obtained also with tables, plots, and linear correlations. The Anova and Tukey´s tests (p<0.01) were used to evaluate data. The results showed that group V presented values: t0:3.09 (± 0.24), t24:3.12 (± 0.36) and t30d:3.15 (± 0.22); T group: t0:3.07 (± 0.16), t24:3.10 (± 0.15), t30d:3.14 (± 0.10), P group: t0:3.13 (± 0.24), t 24:16 (± 0.19), t30d:3.18 (± 0.20); R group: t0:3.08 (± 0.25), t24:3.11 (± .14), t30d:3.13 (± 0.18), C group: t0:3.15 (± 0.31), t24h:3.18 (± 0.15) and t30d: 3.19 (± 0.59), being statistically different from the P group compared to other groups. The commercial brands presented small dimensional changes and according the literature. It can be concluded that pigments can interfere with the elastic property.The storage time is fundamental to evaluate the stability of the polymeric material.

Estabilidade de cor de cerâmica odontológica após glaze e polimento / Color stability of dental ceramics after glaze and polishing

Objetivo: Avaliar a influência de soluções corantes, em diferentes períodos de imersão, na estabilidade de cor de uma cerâmica odontológica em função de diferentes tratamentos de superfície (Glaze e Polimento). Material e Métodos: dezoito amostras de cerâmica foram fabricadas de acordo com as recomendações do fabricante. As amostras foram randomicamente divididas em dois grupos de acordo com o tratamento superficial realizado: Grupo Glaze (controle): glazeadas; Grupo Polimento: amostras polidas com pontas para polimento e pasta diamantada para polimento. Após, três amostras de cada grupo foram imersas em café, vinho tinto ou água por trinta dias. A mensuração de cor foi realizada através de fotografias digitais antes da imersão, após sete, quinze e trinta dias. Os valores de RGB foram obtidos utilizando o programa Adobe Photoshop e convertidos para valores Lab. Teste T de Student, ANOVA e teste Tukey foram utilizados para a análise estatística (p ≤ 0.05). Resultados: os maiores valores de alteração de cor foram proporcionados pelo vinho tinto no grupo glaze (p < 0.05), o grupo glaze e polimento não apresentaram valores de alteração de cor estatisticamente significativos em todas as soluções avaliadas (p > 0.05), as amostras apresentaram estabilidade de cor após 15 dias de imersão nas soluções. Conclusão: o polimento realizado se mostrou tão eficiente quanto o glaze.(AU)

Aim: To evaluate the influence of staining diet solutions at different periods of immersion in the color stability of dental ceramics submitted to different surface treatments (glaze and polishing). Methods: Eighteen samples of ceramics were manufactured according to the manufacturer's recommendations. The samples were randomly divided into two groups according to the surface treatment conducted: Glaze group (control): glazed; Polishing Group: polished samples with tips for polishing and diamond paste forpolishing. After, three samples from each group were immersed in coffee, red wine, or water for thirty days. The measurement was performed using color digital photographs before immersion and after seven, fifteen, and thirty days. The RGB values were obtained using the Adobe Photoshop program and converted to Lab. Student's t test. ANOVA and Tukey test values were used for statistical analysis (p ≤ 0.05). Results: The highest values of color change were provided by red wine in the glaze group (p < 0.05); the polishing and glaze groups showed no statistically significant values of change in color in all of the evaluated solutions (p > 0.05); samples presented color stability after 15 days of immersion in solutions. Conclusion: The polishing performed in this study proved as efficient as the glaze.(AU)

Prótese nasal implantorretida por magnetos ­ relato de caso com cinco anos de acompanhamento / Magnet-retained nasal prosthesis ­ case report with 5-year follow-up

O objetivo do presente estudo foi relatar, por meio de um caso clínico, a reabilitação de uma paciente com uma prótese nasal implantorretida. A mesma possuía 68 anos de idade e foi encaminhada para a reabilitação nasal pela equipe que realizou a cirurgia oncológica de um tumor de pele na região do seu nariz. A paciente reportou queixa com relação à estética da face e problemas no convívio social. Foi proposta reabilitação com prótese nasal, com implantes osseointegráveis associados ao sistema de retenção por magnetos. Após cinco anos e dez meses, três novas próteses foram fabricadas devido a queixas da paciente em relação à descoloração da peça. Na última consulta, a prótese foi removida e inspecionada, e se constatou problemas na higienização, motivo das pigmentações escurecidas na superfície interna da peça e do exsudato no tecido mole ao redor dos pilares protéticos. Foram realizadas a limpeza da barra e do tecido mole, e a confecção de novas próteses nasais implantorretidas à base de silicone elastomérico, além de instrução sobre a necessidade de higienização. Constatou-se que próteses nasais implantorretidas à base de silicone elastomérico são eficientes e seguras para a reabilitação de defeitos na região do nariz. Além disso, é extremamente necessário que o profissional transmita aos pacientes a necessidade de uma higienização satisfatória, solicitando retornos periódicos para obter o máximo do desempenho clínico de suas próteses e implantes.

The aim of present study was to report the rehabilitation of a patient with magnet-retained nasal prosthesis. A 68-year-old female patient was referred to nasal rehabilitation by the surgical team that performed the removal of a skin nose tumor. The patient complained about her facial aesthetics and also reported fearing social interactions. The rehabilitation with nasal prosthesis associated with osseointegrated implants, and retained by magnets was proposed to the patient. After 5 years and 10 months, 3 new prostheses have been fabricated because the patient complained about their discoloration. In the last check-up, the prosthesis was removed and visual inspection revealed lack of hygiene maintenance, which resulted in dark pigments in the intaglio surface as well as exudate in the peri-implant soft skin. The prosthetic components and soft tissue were cleaned, the fabrication of new magnet-retained nasal prosthesis was performed and instructions about the necessity of oral hygiene were also transmitted. The implant-retained nasal prosthesis is an effi cient and safe method for the rehabilitation of defects in the nasal area. Furthermore, it is extremely necessary that clinicians advise patients to perform satisfactory hygiene maintenance and periodic controls in order to obtain long-term success in such cases.