Effect of Conventional and Rolled Cigarette Smoke on the Colour of Artificial Teeth and Effectiveness of Hygiene Protocols in Removing Pigmentation - An in vitro Study

Context: Artificial teeth are widely used in oral rehabilitation. Despite the benefits, they are more susceptible to colour changes, causing aesthetic problems. Aims: To evaluate the effect of conventional cigarette and straw smoke on the colour of artificial teeth and the effectiveness of hygiene protocols in removing pigmentation. Material and Methods: Acrylic resin incisors were divided into two groups (n = 50): Exposed to conventional cigarette and straw smoke. Regarding the effectiveness of hygiene protocols, the teeth were divided into ten subgroups with predetermined immersion times. The colour was measured with a colorimeter. The CIE values L* a* b* were recorded before and after exposure to smoke and after hygiene protocols. Statistical analysis used T?test of independent samples and two?way ANOVA with Bonferroni post?test (? = 0.05). Results: Conventional (16.16 ± 1.65) and straw (16.29 ± 1.95) cigarettes provided clinically unacceptable ?E values, with no significant difference between them (P = 0.719). Conventional cigarettes promoted less luminosity (?L = –12.68 ± 1.28) (P < 0.001) and straw greater tendency to yellow (?b = 11.00 ± 1.46) (P < 0.001). The hygiene protocols influenced the ?E, ?L, and ?b of the samples, depending on the type of smoke (P < 0.05). Conclusions: The conventional and rolled cigarette smoke promote an unacceptable colour change in artificial teeth. Hygiene protocols with the use of brushing, in isolation or in association with chemical solutions are more effective in removing pigmentation caused by both types of cigarettes compared to only the chemical solution

Effectiveness of over-the-counter tooth-whitening strips and toothbrushing for stain removal / Eficácia da utilização de tiras de clareamento dental e da escovação na remoção de manchas dentais

Objective: The present study compared the effectiveness of over-the-counter tooth-whitening strips and too-thbrushing for stain removal. Materials and method: Forty bovine teeth were subjected to initial color re-adings and divided into two groups: 20 teeth were stained with grape juice for seven days and 20 did not receive any treatment (control). Each group was subdivided into two groups (n=10) according to treatment: whitening strips twice/day (30 minutes/7 days) and mechanical brushing with toothpaste (one year). After the treatments, final color readings were taken and color stability (ΔEab), coordinates (ΔL, Δa, Δb), and whitening index (WID) were calculated and analyzed statistically (two-way ANOVA, Bonferroni α=0.05). Results: Statis-tical differences were found for ΔEab and all coordinates between the Control and Stained groups, with major changes in the Stained groups for both treatments. In the Control group, whitening strips produced greater changes in Δb (p <0.05), indicating decrease of yellowness. For the Stained group, whitening strips produced greater changes in Δa (p <0.05), indicating redness reduction. Conclusion: Both treatments were effective for removing stains, and whitening strips were more efficient and effective for changing the color of teeth without previous staining. (AU)

Objetivo: o presente estudo comparou a eficácia das tiras de clareamento dentário e da escovação na remoção de manchas. Materiais e método: quarenta dentes bovinos foram submetidos à lei-tura inicial de cor e divididos em dois grupos: 20 manchados com suco de uva por 7 dias e 20 não receberam tratamento (controle). Cada grupo foi subdividido em 2 grupos (n=10) de acordo com o tratamento: tiras de clareamento 2 vezes/dia (30 minutos/7 dias) e escovação mecânica com cre-me dental (1 ano). Após os tratamentos, leituras finais de cor foram realizadas. Então, a estabili-dade de cor (ΔEab), as coordenadas (ΔL, Δa, Δb) e o índice de clareamento (WID) foram calculados e analisados estatisticamente (two-way ANOVA, Bonferroni α=0,05). Resultados: diferenças es-tatísticas foram encontradas em ΔEab e todas as coordenadas entre os grupos controle e mancha-dos, com maior alteração no grupo manchado, independente do tratamento. No grupo controle, o clareamento produziu maior alteração em Δb (p <0,05), indicando redução do croma amarelo. Nos dentes manchados, ocorreu maior alteração em Δa nos dentes clareados (p <0,05), indicando diminuição do croma vermelho. Conclusão: am-bos os tratamentos foram eficazes na remoção de manchas e o clareamento dentário mostrou-se um método mais eficiente e efetivo para alteração de cor de dentes que não haviam sido submetidos à pigmentação prévia. (AU)

Influence of Different Types of Resin Luting Agents on Color Stability of Ceramic Laminate Veneers Subjected to Accelerated Artificial Aging

Abstract The aim of this study was to evaluate the influence of accelerated aging (AAA) on the color stability of resin cements for bonding ceramic laminate veneers of different thicknesses. The occlusal surfaces of 80 healthy human molars were flattened. Ceramic laminate veneers (IPS e-max Ceram) of two thicknesses (0.5 and 1.0 mm) were bonded with three types of luting agents: light-cured, conventional dual and self-adhesive dual cement. Teeth without restorations and cement samples (0.5 mm) were used as control. After initial color evaluations, the samples were subjected to AAA for 580 h. After this, new color readouts were made, and the color stability (ΔE) and luminosity (ΔL) data were analyzed. The greatest color changes (p<0.05) occurred when 0.5 mm veneers were fixed with light-cured cement and the lowest when 1.0 mm veneers were fixed with conventional dual cement. There was no influence of the restoration thickness when the self-adhesive dual cement was used. When veneers were compared with the control groups, it was verified that the cement samples presented the greatest alterations (p<0.05) in comparison with both substrates and restored teeth. Therefore, it was concluded that the thickness of the restoration influences color and luminosity changes for conventional dual and light-cured cements. The changes in self-adhesive cement do not depend on restoration thickness.

Resumo O objetivo deste estudo foi avaliar a influência do envelhecimento artificial acelerado (EAA) sobre a estabilidade de cor de cimentos resinosos para fixação de laminados cerâmicos em diferentes espessuras. Oitenta molares humanos hígidos tiveram as faces oclusais planificadas. Laminados cerâmicos (IPS e-max Ceram, Ivoclar Vivadent) em duas espessuras (0,5 e 1,0mm) foram fixados com 3 tipos de cimentos: Fotoativado (Variolink II, Ivoclar/Vivadent), Dual convencional (Variolink II + catalisador, Ivoclar/Vivadent) ou Dual auto-adesivo (Rely-X Unicem, 3M ESPE). Dentes sem restaurações e amostras de cimentos (0,5mm) foram utilizados como controle. Após as leituras de cor iniciais (Vita EasyShade, VITA), as amostras foram submetidas a EAA por 580 horas. Em seguida, novas leituras de cor foram realizadas e os dados de estabilidade de cor (ΔE) e luminosidade (ΔL) foram analisados (ANOVA, dois fatores e Bonferroni, p<0,05). As maiores alterações de cor (p<0,05) ocorreram quando as restaurações de 0,5 mm foram fixadas com cimento fotoativado, e as menores quando restaurações de 1.0mm foram fixadas com cimento dual convencional. Não houve influência (p>0,05) da espessura da restauração quando utilizado o cimento dual autoadesivo. Quando as restaurações foram comparadas aos grupos controle (ANOVA um fator e Tukey, p<0.05), verificou-se que as amostras de cimento apresentaram as maiores alterações (p<0,05) em relação ao substrato e aos dentes restaurados. Conclui-se que a espessura da restauração influencia na alteração de cor e na luminosidade do cimento dual convencional e fotoativado. As alterações do cimento autoadesivo não dependem da espessura da restauração.

Color stability and surface roughness of artificial teeth brushed with an experimental Ricinus communis toothpaste

To evaluate, in vitro, the effect of brushing with a Ricinus communis-based experimental toothpaste on color stability and surface roughness of artificial teeth. Methods: Ninety artificial teeth (maxillary central incisors) in different shades, light and dark (NatusDent Triple Pressing, Dentbras) were used. Initial color (Spectrophotometer Easyshade, VITA) and surface roughness (Rugosimeter Surfcorder SE 1700, Kosakalab) readouts were performed. After baseline measurements, samples were assigned to 10 groups (n=9) according to the artificial tooth shade and type of toothpaste used during the mechanical brushing test (Pepsodent, MAVTEC): Sorriso Dentes Brancos - SDB, Colgate Luminous White - CLW (Colgate-Palmolive), Close up White Now - CWN (Unilever), Trihydral - THL (Perland Pharmacos) and Ricinus communis - RCE (Experimental). After 29,200 cycles of brushing, corresponding to 2 years of brushing by a healthy individual, new color and roughness readouts of the specimens were performed. Data (before and after the tests) were statistically analyzed (2-way repeated measures ANOVA, Tukey, p<0.05). Results: RCE toothpaste produced the greatest color stability for dark tooth shade and the second best color stability for light tooth shade. For surface roughness alteration, there was no difference (p>0.05) for any tested toothpaste regardless of tooth shade. Conclusions: The experimental Ricinus communis toothpaste did not cause color and surface roughness alteration in the artificial teeth, and it may be considered a suitable option for denture cleaning...

Effect of polishing and brushing on removal of cigarette smoke stains from artificial teeth / Efecto del pulido y cepillado en la eliminación de manchas de humo de cigarrillo en dientes artificiales

Color alteration is still a disadvantage of acrylic resin teeth and this problem seems to be greater in smokers. The objective of this study was to evaluate the efficiency of polishing and brushing on removal of stains from artificial teeth submitted to cigarette smoke. Forty denture teeth of distinct shades (62 and 69) were selected. The teeth were divided into 4 groups (n= 10), according to the tooth shade and method of stain removal performed: Groups 1 and 2 were submitted to the smoke of 20 cigarettes, and after new color readouts, were submitted to polishing with pumice stone and Spanish white paste. Groups 3 and 4 were submitted to 4 cycles of 5 cigarettes interspersed with standardized manual brushing. The values of color stability (DE) were compared using 2-way ANOVA, Bonferroni test (p<0.05). For all the groups, color change occurred at clinically unacceptable levels (E>3.3). After exposure to 20 cigarettes, the greatest degree of color change occurred for teeth in shade 62. Polishing significantly reduced the color change for groups 1 and 2, however, without significant difference between them. For Groups 3 and 4 there was no difference between the teeth of shade 62 and 69. When the treatments for each tooth shade were compared alone, there was similarity between polishing and brushing irrespective of the shade of samples. Routine manual brushing and common clinical polishing methods were capable of removing a large portion of staining caused by cigarettes, and there was no difference between the methods.

La alteración del color sigue siendo una desventaja de los dientes de resina acrílica y este problema parece ser mayor en los fumadores. El objetivo de este estudio fue evaluar la eficacia de pulido y cepillado en la eliminación de manchas de los dientes artificiales presentados al humo del cigarrillo. Se seleccionaron cuarenta dientes de la dentadura de tonos diferentes (62 y 69). Los dientes fueron agrupados en 4 grupos (n= 10), de acuerdo con el color del diente y el método de eliminación de manchas realizado: Los grupos 1 y 2 fueron sometidos al humo de 20 cigarrillos, y después de nuevas lecturas de color, se pulieron con piedra pómez piedra y pasta blanca española. Los grupos 3 y 4 se sometieron a 4 ciclos de 5 cigarrillos intercalados con cepillado manual estandarizado. Los valores de estabilidad del color (Delta E) se compararon mediante las pruebas de ANOVA de dos vías y Bonferroni (p<0,05). Para todos los grupos, el cambio de color se produjo a niveles no aceptables clínicamente (DE>3,3). Después de la exposición a 20 cigarrillos, el mayor grado de cambio de color se produjo para los dientes de tono 62. El pulido redujo significativamente el cambio de color para los Grupos 1 y 2, sin diferencia significativa entre ellos. Para los Grupos 3 y 4 no hubo diferencia entre los dientes de tono 62 y 69. Cuando los tratamientos para cada color de diente se compararon individualmente, hubo similitud entre el pulido y el cepillado, independientemente del tono. El cepillado manual rutinario y los métodos comunes de pulido clínicos fueron capaces de eliminar una gran parte de manchas causadas por los cigarrillos, sin diferencia entre los métodos.

Effect of Brushing Time and Dentifrice Abrasiveness on Color Change and Surface Roughness of Resin Composites

Abstract: Dentifrice abrasiveness and brushing time may increase color change (∆E) and surface roughness (∆Ra) of resin composites. This study aimed to evaluate the effect of mechanical brushing time of dentifrices with different abrasiveness on ∆E and ∆Ra of nanofilled (Z350, 3M ESPE) and nanohybrid (Tetric N-Ceram, Ivoclar Vivadent) resin composites. Sixteen specimens (12 mm diameter x 2 mm thick) were fabricated using a white Teflon matrix of each resin composite and a ceramic (IPS e.max Ceram, Ivoclar Vivadent), used as control. After initial color readouts on white backgrounds (Spectrophotometer PCB 6807, Byk Gardner), with D65 standard illuminant, and surface roughness (Rugosimeter Surfcorder SE 1700, Kosalab) with cut-off=0.8 mm and speed=0.25 mm/s, specimens were assigned (n=8) according to the abrasiveness of the dentifrices: RDA* 68 (Colgate) and RDA* 180 (Colgate Total Plus Whitening). Specimens were submitted to mechanical brushing (58,400 cycles) and after every 14,600 cycles (1 year of brushing by a healthy individual), new color and surface roughness readouts were taken. Color stability was calculated by CIEDE2000. Data were analyzed by 3-way repeated measures ANOVA and Bonferroni test (p<0.05), and demonstrated that the dentifrice abrasiveness (p=0.02) and brushing time (p<0.0001) affected the ∆E of nanofilled resin composite. There was no difference on surface roughness of materials (p=0.6752) or brushing time (p=0.7997). In conclusion, the longer the brushing time and dentifrice abrasiveness, the greater the color change of the nanofilled resin composite. The surface roughness was not influenced by dentifrice abrasiveness.

Resumo: A abrasividade do dentifrício e o tempo de escovação podem aumentar a alteração de cor (∆E) e rugosidade de superfície (∆Ra) das resinas compostas. Este estudo teve como objetivo avaliar o efeito do tempo de escovação mecânica com dentifrícios de diferentes abrasividades, sobre o ∆E e a ∆Ra das resinas compostas (nanoparticulada, Z350, 3M ESPE e nanohíbrida, Tetric N-Ceram, Ivoclar Vivadent). Dezesseis amostras (12 mm de diâmetro x 2 mm de espessura) foram obtidas utilizando uma matriz de teflon branca, de cada resina composta e uma cerâmica (IPS e.max Ceram, Ivoclar Vivadent), considerada como controle. Após as leituras iniciais de cor sobre fundo branco (Espectrofotômetro PCB 6807, Byk Gardner), com iluminante padrão D65, e de rugosidade de superfície (Rugosímetro Surfcorder SE 1700, Kosalab), com cut-off=0,8 mm e velocidade=0,25 mm/s, as amostras foram separadas (n=8) de acordo com a abrasividade dos dentifrícios: RDA* 68 (Colgate) e RDA* 180 (Colgate Total Plus Whitening). Amostras foram submetidas a escovação mecânica (58.400 ciclos), sendo que a cada 14.600 ciclos (1 ano de escovação por um indivíduo saudável), novas leituras de cor e rugosidade de superfície foram realizadas. A estabilidade de cor foi calculada segundo CIEDE2000. Os dados foram analisados (3-way ANOVA medidas repetidas, teste de Bonferroni, p<0,05), e demonstrou-se que a abrasividade dos dentifrícios (p=0,02) e o tempo de escovação (p<0,0001) afetaram o ∆E da resina composta nanoparticulada. A rugosidade de superfície não foi influenciada pela abrasividade dos dentifrícios (p=0,6752) ou tempo de escovação (p=0,7997). Concluiu-se que quanto maior o tempo de escovação mecânica e a abrasividade do dentifrício, maior a alteração de cor da resina composta nanoparticulada. A rugosidade de superfície não foi influenciada pela abrasividade do dentifrício.