Color variation of composite resins in relation to the Vita Classical shade guide: colorimetric analysis

Aim: The aim of this study was to verify the color variation between different composite resins and the Vita Classical Shade Guide. Methods: Two-millimeter thickness samples were made (n = 6) from eight commercial brands of composite resin (shade A2): Charisma (Kulzer), Forma (Ultradent), Harmonize (Kerr), Luna (SDI), Opallis (FGM), Oppus Bulk Fill (FGM), Vittra (FGM) and Filtek Z250 XT (3M ESPE). Specimens were stored in distilled water for 7 days and then polished. Color measurements of samples and A2 shade of the Vita Classical Shade Guide were performed using the Vita Easy Shade Advance 4.0 spectrophotometer on a black background. Color variations were calculated using the CIEDE2000 formula, considering values ≥0.81 being noticeable by the human eye and ≥1.77 being clinically unacceptable. Results were statistically analyzed with a 5% significance level. Results: Color variation (ΔE) of composite (E1 ) compared to the Vita Classical Shade Guide (E0 ) was greater than clinically acceptable for all the materials evaluated in this study. Forma (ΔE=2.08 ± sd=0.47) and Filtek Z250 XT (2.50 ± 0.20) had the smallest amount of color variation values found in the results. Harmonize (3.32 ± 0.63) presented values similar to Filtek Z250 XT, but it was worse than Forma. Vittra (3.51 ± 0.28), Charisma (3.80 ± 0.20), Opallis (4.24 ± 0.30) and Luna (5.67 ± 0.20) did not differ among each other and presented higher color variation than Forma, Filtek Z350XT and Harmonize. Oppus Bulk Fill (13.94 ± 1.12) was the composite with the greatest color variation. Conclusions: The findings in this study show that attention should be taken when using the Vita Color Shade Guide for composite shade selection

Influence of number and position of porcelain specimens in the furnace on flexural strength and translucency

The aim of this study was to investigate the influence of the quantity and positioning of feldspathic ceramic specimens inside the furnace on their flexural strength and translucency. The tested hypotheses were that the arrangement of specimens in the furnance would not influence 1) the translucency or 2) the biaxial strength of the porcelain. Methods: Ninety porcelain specimens were made (1.2 mm thickness and 13.5 mm diameter) and assigned into two main groups (n=15): G1 group - 15 firing cycles containing only one specimen each, always at the center of the refractory; and G5 group - 15 firing cycles containing five specimen each, where one specimen was at the center of the refractory and four specimens positioned equidistantly on the periphery. The translucency test was performed using a spectrophotometer, followed by the flexural strength test, according to ISO 6872:2015. T-student test was performed for both the mechanical and optical obtained data. Results: The flexural strength of the porcelain was not affected by the positioning (center x periphery) of the specimens inside the furnace (p =0.08), but the translucency was affected (periphery > center; p =0.009). Regarding to the number of feldspathic ceramic specimens, the biaxial flexural strength was affected (p =0.025), as well as the translucency (p <0.05). Conclusion: A higher quantity of feldspathic ceramic specimens for each firing cycle decreased its biaxial flexural strength and translucency. Also, specimens positioned at the center of the refractory became less translucent than those positioned at the periphery.

Nicotine is a potent extracellular polysaccharide inducer in Fusobacterium nucleatum biofilms

The purpose of this in vitro study was to analyze the influence of nicotine on the extracellular polysaccharides in Fusobacterium nucleatum biofilm. Methods: F. nucleatum (ATCC 10953) biofilms supplemented with different concentrations of nicotine (0, 0.5, 1, 2, 4, and 8 mg/mL) were grown in two different BHI broth conditions [no sucrose and 1% sucrose]. Extracellular polysaccharides assay, pH measurements, and a spectrophotometric assay were performed. Data were submitted for ANOVA and Tukey honestly significant difference analyses (HSD) tests (α =.05). Results: Extracellular polysaccharides synthesis was influenced by an interaction between nicotine concentrations and growth medium solution containing sucrose (P<.05). The pH values declined in the sucrose-exposed biofilm were greater than in the group exposed only to nicotine (P<.05). The biofilm exposed to sucrose and nicotine had a higher total biofilm growth (P<.05) than the nicotine-treated biofilm without sucrose. Conclusions: Regardless of sucrose exposure, biofilms exposed to different nicotine concentrations influenced the amount of extracellular polysaccharides

Curcumin Mediated Gold Nanoparticles and Analysis of its Antioxidant, Anti-inflammatory, Antimicrobial Activity Against Oral Pathogens

ABSTRACT Objective: To green synthesise gold nanoparticles using curcumin and to analyse its antioxidant, anti-inflammatory, and antimicrobial activity among oral pathogens. Material and Methods: Biosynthesised Curcumin Gold nanoparticles (CuAuNP) were evaluated by UV-visible spectrophotometer (UV-Vis), Transmission Electron Microscopy (TEM), and evaluation of antioxidant, anti-inflammatory and antibacterial activity against oral pathogens. Results: Synthesized CuAuNP were characterized using UV-visible spectrophotometry and showed peak absorption at 530nm. CuAuNp showed a 90.3% maximum scavenging ability of DPPH at a concentration of 50 μg/mL. CuAuNP exhibited 79.6 % of the highest anti-inflammatory activity at 50μg/mL than the standard drug diclofenac. TEM image clearly showed uniformly dispersed spherical-shaped gold nanoparticles with a size of about 20 nm. The biosynthesized nanoparticle was tested for its antimicrobial effect, and it showed a potent effect against S. aureus, E. faecalis, and C. albicans at 100µg/ mL. Enterococcus faecalis has a maximum zone of inhibition of 14 mm at 100µg/ mL of CuAuNp. Among gram-positive bacteria, a maximum zone of inhibition of 12 mm at 100µg/ mL was seen in S. aureus compared to S mutans. Candida albicans showed a maximum zone of inhibition of 18 mm at 25 μg/mL of CuAuNp. Conclusion: Curcumin-mediated gold nanoparticles with 20 nm size were effective and had strong antioxidant and anti-inflammatory activity at 50µg/ mL, antimicrobial action inhibiting microbes at 100µg/mL concentration that can be used in treating various Oral mucosal lesions.

Efeito do probiótico lactobacilus casei adjunto a terapia periodontal em modelo experimental de periodontite: uma relação entre periodonto e intestino / Effect of the probiotic lactobacilus casei as an adjunct to periodontal therapy in an experimental model of periodontitis: a relationship between periodontium and intestine

A periodontite é uma condição crônica inflamatória que pode influenciar a microbiota intestinal. O tratamento padrão ouro para a periodontite inclui a raspagem e o alisamento corono-radicular (RACR), porém em casos complexos pode-se utilizar terapias adjuvantes, como os probióticos. A utilização deste tratamento adjuvante poderá contribuir para a melhoria da condição periodontal e a simbiose intestinal. O objetivo deste estudo foi avaliar o efeito na inflamação periodontal e intestinal da utilização do Lactobacillus casei (LC) adjunto a RACR em camundongos Balb/c com periodontite, induzida por ligadura. Este estudo é um ensaio pré-clínico, in vivo, randomizado, cego e controlado por placebo, constituído por 36 camundongos Balb/c machos. Os animais foram submetidos a indução da periodontite por colocação de ligadura com fio de seda 4.0 ao redor do segundo molar superior direito, sendo divididos em 4 grupos,o grupo controle: Sem Periodontite e sem RACR (n=8); Grupo Ligadura: Com Periodondite e sem RACR (n=10); Grupo raspagem: Com Periodontite e com RACR (n=10) ; Grupo raspagem + L.casei (n=8): Com Periodontite e com RACR + administração de LC, por gavagem, durante 30 dias. Foram realizadas análises de citocinas pelo método ELISA no tecido gengival (IL-6), intestinal (IL-1ß, IL-6 e IL-10) e sanguíneo (IL-1ß e IL-6), além de análises bioquímicas (TGO, TGP, ureia e creatinina) e contagem diferencial de leucócitos do sangue. Foram coletados fragmentos do intestino grosso desses animais e analisados quanto a biomarcadores do estresse oxidativo (SOD, GSH e MDA), atividade da acetilcolinesterase (AChE) e foi realizada contagem da população de Bactérias Produtoras de Ácido Láctico das fezes dos animais. A utilização do LC adjunto a RACR resultou em uma redução na expressão da IL-6 no tecido gengival de camundogos com Periodontite (p < 0,05). Para as inteleucinas séricas (IL-1ß e IL-6), não houve diferenças entre os grupos (p > 0,05). Já para as citocinas intestinais houve uma redução na expressão de IL-10 (p < 0,05), para os grupos em que foi induzida a Periodontite. Com relação ao estresse oxidativo intestinal os animais do Grupo raspagem e raspagem + LC tiveram uma redução dos níveis de MDA (p < 0,05), para a SOD e o GSH, não houve diferenças significativas entre os 4 grupos pesquisados (p < 0,05). Conclui-se que o uso de LC adjunto a RACR em camungongos com periodontite induzida por ligadura pode reduzir a liberação de IL-6 no tecido gengival. Com relação aos efeitos intestinais foi observada a modulação da resposta inflamatória, com a redução de MDA, nos animais que receberam o tratamento periodontal. E a redução da expressão da IL-10, nos animais com Periodontite (AU).

Periodontitis is a chronic inflammatory condition that can influence the gut microbiota. The gold standard treatment for periodontitis includes scaling and crown-root planing, but in complex cases adjuvant therapies such as probiotics can be used. The use of this adjuvant treatment may contribute to the improvement of periodontal condition and intestinal symbiosis. The aim of this study was to evaluate the effect on periodontal and intestinal inflammation of the use of Lactobacillus casei (LC) adjunct to scaling and root planing (RACR) in Balb/c mice with ligature-induced periodontitis. This study is a preclinical, in vivo, randomized, blinded, placebo-controlled trial consisting of 40 male Balb/c mice. The animals were submitted to periodontitis induction by placing a 4.0 silk suture ligature around the upper right second molar. The sample was divided into 4 groups, each with 10 animals: Group I: Without Periodontitis and without RACR; Group II: With Periodontitis and without RACR; Group III: With Periodontitis and with RACR; Group IV: With Periodontitis and with RACR + gavage of LC, for 30 days. Cytokine analyzes were performed by the ELISA method in gingival tissue (IL-6), intestinal tissue (IL-1ß, IL-6 and IL-10) and blood (IL-1ß and IL-6), the blood was also subjected to analysis biochemical (TGO, TGP, urea and creatinine) and differential leukocyte count. Fragments of the large intestine of these animals were collected and analyzed for biomarkers of oxidative stress (SOD, GSH and MDA), acetylcholinesterase (AChE) activity, and the population of Lactic Acid-Producing Bacteria in the animals' feces was counted. The use of LC adjunct to RACR resulted in a reduction in the expression of IL-6 in the gingival tissue of mice with Periodontitis (p < 0.05), for the blood inteleukins (IL-1ß and IL-6), there were no differences between the groups (p > 0.05). As for intestinal cytokines, there was a reduction in the expression of IL-10 (p < 0.05), for the groups that presented Periodontitis. Regarding intestinal oxidative stress, the animals in Groups III and IV had a reduction in MDA levels (p < 0.05), for SOD and GSH, there were no significant differences between the 4 groups studied (p < 0.05 ). It is concluded that the use of LC adjunct to RACR in mice with ligation-induced periodontitis can reduce the release of IL-6 in the gingival tissue. Regarding the intestinal effects, two effects were found: The first related to the modulation of the inflammatory response, with the reduction of MDA, in the animals that received periodontal treatment. And the second related to a pro-inflammatory effect, with the reduction of IL-10 expression (AU).

The Effect of Coloring Beverages on Color Stability of Hybrid Ceramics with Different Surface Treatments

ABSTRACT Objective To assess the effects of coloring beverages on the color stability of two types of hybrid ceramics with different surface treatments. Material and Methods 180 specimens of two hybrid ceramics (Vita Enamic and Mazic Duro) and a feldspathic ceramic (Vita Mark II) were prepared (n=60 in each group). Half of the discs in each group were glazed while the other was polished. The specimens were then divided into three subgroups and immersed in distilled water, carrot juice, and coffee. The overall color difference (∆E) was calculated based on CIE L*a*b* color space. Data were analyzed using three-way and one-way ANOVA; Tukey's honest significant difference was also done for pairwise comparisons (α=0.05). Results Vita Mark II specimens revealed less overall color changes compared to other groups. The ∆E of the glazed Vita Enamic specimens was greater than polished specimens following immersion in distilled water (p=0.03) and coffee (p=0.001), but it was not significant for carrot juice. The same results were obtained for polished Mazic Duro specimens. Relatively similar amounts of ∆E were recorded in polished and glazed subgroups of Vita Mark II. Conclusion The ∆E of hybrid ceramics was higher than Vita Mark II. Polishing could be recommended for surface treatment of hybrid ceramics instead of glazing, saving time and facilitating the process.

Comparison of color difference and reliability of two intraoral spectrophotometers

Aim: to evaluate the intra and inter-device reliability of two intraoral spectrophotometers in measuring the Commission Internationale de l'Éclairage (CIE) L*a*b* color coordinates and to compare the color difference (ΔE) between both devices. Methods: the central region of the labial surface of the maxillary central incisor of 31 participants was measured twice by each of the devices (VITA EasyShade and Degudent Shadepilot) by one examiner. CIE L*a*b* color coordinates were obtained for all teeth and ΔE was measured and compared. Intraclass correlation coefficient (ICC) and Mann-whitney U test were used to analyze the data (p<0.05). Results: inter-device reliability ICCs in measuring CIE L*a*b* color coordinates ranged between 0.08-0.49 with significant difference between devices only concerning the b coordinate (p<0.05). While intra device reliability ICCs ranged between 0.86-0.89 for VITA EasyShade and 0.81-0.86 for Degudent Shadepilot. The mean ΔE for CIE L*a*b* color coordinates of VITA EasyShade was 3.61 (±1.93) compared to 3.60 (± 1.45) for Degudent Shadepilot with insignificant difference between both devices (p>0.05). Conclusions: high intra device reliability in measuring CIE L*a*b* color coordinates was achieved particularly of Vita EasyShade, and both devices had clinically acceptable color difference (ΔE <3.7) however, inter device reliability was low to moderate. Consequently, the same spectrophotometer should be used throughout the steps of performing any tooth- colored restoration

Comparação entre as avaliações visual e instrumental da cor dentária: uma revisão da literatura / Comparison between the visual and instrumental assessments of dental color: a literature review

O objetivo do estudo foi realizar uma revisão narrativa da literatura para comparar os métodos visual e instrumental de seleção da cor dentária, correlacionando-os com o fator experiência e a educação continuada. Utilizou-se como base de dados a MEDLINE na qual foram aplicados os descritores "visualshade match", "color measurement", "spectrophotometer" e "tooth color determination". Os critérios de inclusão foram artigos publicados entre 2010 e 2020que abordassem uma análise comparativa entre as duas modalidades de seleção da cor dentária. Se enquadraram nos critérios de exclusão estudos que não contemplavam a temática abordada e aqueles publicados nos anos anteriores a 2010, além das revisões de literatura. No total, onze artigos foram selecionados para compor essa revisão. Os estudos demonstraram que o método instrumental apresentou maior confiabilidade e reprodutibilidade quando comparado ao método visual, isso se deve ao fato de a escolha de cor através de instrumentos eletrônicos proporcionar melhor precisão e atenuação da subjetividade. No que concerne a experiência como fator influenciador da seleção de cor, os estudos são controversos. Mesmo evidenciando melhor precisão, a estimativa instrumental apresenta limitações devido à dificuldade de aferição em função da convexidade da anatomia dentária. Desse modo, foi descrito que a associação de métodos é capaz de elevar a confiabilidade da escolha de cor, melhorando o resultado estético. Não houve consenso entre os estudos com relação à influência da experiência, no entanto, a educação continuada foi sugerida na literatura como alternativa para formar profissionais mais confiantes no processo de seleção de tonalidades(AU)

The goal of this study was to carry out a narrative review of the literature to compare the visual and instrumental methods of tooth color selection, correlating them with the experience factor and continuing education. MEDLINE was used as a database in which the descriptions such as "visual shade match", "color measurement", "spectrophotometer" and "tooth color determination" were applied. The inclusion criteria were articles published between 2010 and 2020 that addressed a comparative analysis between the two types of tooth color selection. The exclusion criteria included studies that did not contemplate the theme addressed and those published in the years prior to 2010, in addition to literature reviews. In total, eleven articles were selected to compose this review. Studies have shown that the instrumental method showed greater reliability and reproducibility when compared to the visual method, this is due to the fact that the color's choice through electronic instruments provides better precision and lessened subjectivity. Regarding experience as na influencing factor in color selection, studies are controversial. Even with better precision, the instrumental estimation has limitations due to the difficulty of measuring it due to the convexity of the dental anatomy. Thus, it was described that the association of the methods is able to increase the reliability of the color's choice, improving the aesthetic result. There was no consensus among the studies in regard to the experiment's influence, however, continuing education was suggested in the literature as an alternative in order to form more confident professionals when it comes to the shade selection process(AU)

Avaliação da cor de resinas compostas através dos métodos visual e digital / Analysis of the color of composite resins through visual and digital methods / Evaluación del color de resinas compuestas a través de métodos visuales y digitales

Objetivo: O presente estudo teve como objetivo verificar a correspondência de cor das resinas compostas em relação à Escala Vita, através do método visual e do método digital. Material e método: Trata-se de um estudo laboratorial in vitro realizado com 24 corpos de prova, utilizando resinas compostas de 8 diferentes marcas de resinas, nas cores A1, A2 e A3, os quais foram submetidos à análise de tomada de cor, tanto pelo método visual quanto pelo método digital com auxílio de um scanner. Os dados foram analisados de forma descritiva e analítica por meio do Teste Qui-quadrado e o Teste de Fisher para comparar as frequências das coincidências pelo método visual e digital, de acordo com a marca, cor e método. Resultados: 41,67% das resinas apresentaram correspondência de cor quando avaliadas pelo método visual, enquanto o método digital apresentou 29,17% de correspondência de cor. As cores propostas não foram identificadas nem pelo método digital e nem pelo método visual (92.6%), com diferença significativa (p<0,05). Quando comparado as frequências de coincidências, houve mais coincidências pela identificação da cor pelo método visual do que pelo método digital (p<0,05). Conclusão: Os métodos digital e visual clássico apresentaram pouca correspondência entre a cor proposta pelos fabricantes e a cor obtida após a polimerização das resinas. E quando comparadas as frequências de coincidências das cores, estas foram mais identificadas pelo método visual do que pelo método digital(AU)

Objective: The present study aimed to verify the color correspondence of composite resins in relation to the Vita Scale, through the visual method and the digital method. Material and method: This is an in vitro laboratory study carried out with 24 specimens, using resins composed of 8 different resin brands, in colors A1, A2 and A3, which were subjected to the analysis of color taking, both by the visual method as well as by the digital method with the aid of a scanner. The data were analyzed in a descriptive and analytical way using the Chi-square test and the Fisher test to compare the frequencies of coincidences by the visual and digital method, according to the brand, color and method. Results: 41.67% of the resins showed color matching whenevaluated by the visual method, while the digital method showed 29.17% color matching. The proposed colors were identified neither by the digital method nor by the visual method (92.6%), with a significant difference (p <0.05). When compared the frequencies of coincidences, there were more coincidences by identifying the color by the visual method than by the digital method (p <0.05). Conclusion: The digital and classic visual methods showed little correspondence between the color proposed by the manufacturers and the color obtained after polymerization of resins. And when comparing the frequencies of color coincidences, they were more identified by the visual method than by the digital method(AU)

Objetivo: El presente estudio tuvo como objetivo verificar la correspondencia de colores de las resinas compuestas en relación con la Escala Vita, utilizando el método visual y el método digital. Material y método: Se trata de un estudio de laboratório in vitro realizado con 24 probetas, utilizando resinas compuestas por 8 marcas de resina diferentes, en los colores A1, A2 y A3, las cuales fueron sometidas al análisis de toma de color, tanto por el método visual como así como por el método digital con la ayuda de un escáner. Los datosse analizaron de forma descriptiva y analítica mediante la prueba de Chi-cuadrado y la prueba de Fisher para comparar las frecuencias de coincidencias por el método visual y digital, según marca, color y método. Resultados: el 41,67% de las resinas mostraron coincidencia de color cuando se evaluaron por el método visual, mientras que el método digital mostró una coincidencia de color del 29,17%. Los colores propuestos no fueron identificados ni por el método digital ni por el método visual (92,6%), con una diferencia significativa (p <0,05). Al comparar las frecuencias de coincidencias, hubo más coincidencias al identificar el color por el método visual que por el método digital (p <0.05). Conclusión: Los métodos visuales digitales y clásicos mostraron poca correspondencia entre el color propuesto por los fabricantes y el color obtenido tras la polimerización de resinas. Y al comparar las frecuencias de las coincidencias de color, se identificaron más por el métodovisual que por el método digital(AU)

Salivary and Serum Biochemical Analysis from Patients with Chronic Renal Failure in Hemodialysis: A Cross-Sectional Study

ABSTRACT Objective: To compare salivary and serum biochemical levels in patients with chronic renal failure undergoing hemodialysis. Material and Methods: The sample was composed of 57 patients treated in Hemodialysis Reference Centers, from a state of Northeastern Brazilian, with age ≥21 years old with at least 3 months of hemodialysis treatment time. Serum data were obtained from records. Unstimulated and stimulated saliva were collected. Flow rate (mL/min) was measured. Spectrophotometry was performed for the measurement of salivary levels of calcium (570 nm), urea (340 nm), and creatinine (510 nm). Statistical analysis used Mann Whitney and Kruskal-Wallis tests (p<0.05). Results: Unstimulated and stimulated salivary flow rates were 0.43 mL/min and 1.69 mL/min, respectively. There was significant difference (p<0.001) of levels of calcium (5.41 mg/dL and 9.70 mg/dL), urea (118.03 mg/dL and 183.22 mg/dL) and creatinine (0.59 mg/dL and 9.20 mg/dL) between saliva and serum, respectively. Concerning the time of hemodialysis, salivary and serum calcium not exhibited significant association; however, serum urea (p=0.012) and serum creatinine (p=0.025) showed significant association to the time of hemodialysis. Conclusion: Salivary biochemical levels of urea, creatinine and calcium can indicate the presence of a possible chronic renal failure and the saliva demonstrated to be a potential auxiliary biofluid for clinical monitoring renal alterations.

Spectrophotometric Analysis of Streptococcus mutans Growth and Biofilm Formation in Saliva and Histatin-5 Relate to pH and Viscosity

ABSTRACT Objective: To analyze the ability of saliva in controlling the growth and the biofilm formation of Streptococcus mutans (S. mutans) as well as the effect of histatin-5 anti-biofilm relate to pH and saliva viscosity. Material and Methods: The S. mutans biofilm assayed by crystal violet 1% and its growth measured by spectrophotometer. The saliva viscosity was analyzed by viscometer, and pH of saliva was measured by pH meter. Results: Based on the optical density values, growth of S. mutans in saliva ranged <300 CFU/mL (0.1 nm) at concentrations of 25%, 12.5% and 6.25% for 24 hours. Whereas at the 48 h and 72 h period of incubation shown an increase in growth of S. mutans ranged 300-600 CFU/mL (0.2-0.36 nm). The inhibitory biofilm formation of S. mutans in saliva was significantly higher at concentrations of 12.5% and 6.25% at 24 h incubation times on a moderate scale, whereas the histatin-5 was effective to inhibit S. mutans biofilm on the 50 and 25 ppm. The saliva possessed a higher inhibitory of biofilm S. mutans than histatin-5 and good level viscosity (0.91-0.92 cP). Conclusion: The saliva was able to control the growth of S. mutans, and histatin-5 can inhibit the biofilm formation S. mutans. Furthermore, the saliva was also able to respond to the pH change with good viscosity of saliva.

Antibacterial and Solubility Analysis of Experimental Phytotherapeutic Paste for Endodontic Treatment of Primary Teeth

ABSTRACT Objective: To evaluate the antibacterial effect and the solubility of experimental root canal filling pastes containing the phytoconstituents terpineol and cinnamaldehyde. Material and Methods: Minimum Inhibitory Concentration (MIC) of each phytoconstituent was determined against Enterococcus faecalis. Five groups of antibiotic pastes based on zinc oxide were obtained by mixing: only terpineol, only cinnamaldehyde, terpineol and cinnamaldehyde combined, chlorhexidine (antibiotic control), and CTZ paste (control paste). Antibacterial activity was analyzed through direct contact test within 24 and 72 hours. Solubility was evaluated by spectrophotometry within 48 and 144 hours. Antibacterial activity data were analyzed descriptively, and solubility data was analyzed using ANOVA and Tukey tests (p<0.05). Results: The MIC obtained for terpineol and cinnamaldehyde were, respectively, 2000 µg/mL and 500 µg/mL. After 24h, only the terpineol paste did not inhibit E. faecalis growth. After 72h, all groups inhibited E. faecalis growth. After 48h, the highest solubility was verified in the terpineol paste (p<0.05), and no differences were detected among other groups (p>0.05). After and 144h, highest solubility was observed in the terpineol paste (p<0.05), followed by the CTZ paste (p<0.05). No differences were detected for cinnamaldehyde, terpineol+cinnamaldehyde and chlorhexidine pastes (p>0.05). Conclusion: Pastes containing cinnamaldehyde or terpineol+cinnamaldehyde showed antibacterial activity against E. faecalis similar to CTZ paste, with lower solubility.

Antimicrobial activity of intracanal dressings composed by natural products associated to chlorhexidine and its influence on dentinal colour change / Avaliação da ação antimicrobiana de medicações intracanais à base de produtos fitoterápicos associados à clorexidina e sua influência na alteração de cor da estrutura dentinária

Purpose: evaluate the antimicrobial activity of intracanal dressings and their influence on dentinal colour changes. Material and methods: eighty single-rooted human extracted teeth were decoronated and divided into eight groups (n=10) according to intracanal dressing protocols inserted into the root canals: G1­distilled water (DW); G2­2% chlorhexidine gel (CHX); G3­calcium hydroxide (Ca[OH]2)+DW; G4­grape seed extract (GSE)+DW; G5­ginger extract (GE)+DW; G6­Ca(OH)2+CHX; G7­GSE+CHX; and G8­GE+CHX. The antimicrobial activity was evaluated by colony-forming units (CFUs) counting and dentinal colour changes was evaluated by digital spectrophotometry. Data were statistically analysed by One-way ANOVA followed by Tukey´s post hoc test (antimicrobial evaluation) and non-parametric Wilcoxon followed by the Mann- Whitney-U test (colour change evaluation) (α=0.05). Results: the highest bacterial reduction was observed in groups 4, 6, 7 and 8, with no significant difference between them (p<0.05). Groups 4 and 7 showed the highest medians of dentinal colour change (p<0.05). Conclusion: the addition of CHX improved the antimicrobial activity of GE-based intracanal dressing, with no effect in GSE-based intracanal dressing; moreover, these protocols induced significant dentinal colour changes. (AU)

Objetivo: avaliar a atividade antimicrobiana de medicações intracanais e sua influência na alteração da cor dentinária. Materiais e métodos: oitenta dentes humanos extraídos unirradiculares foram seccionados e divididos em oito grupos (n = 10), de acordo com os protocolos de medicação intracanal inseridos nos canais radiculares: água destilada G1 (DW); G2-2% de gel de clorexidina (CHX); hidróxido de cálcio G3 ­ (Ca [OH] 2) + DW; extrato de semente de uva G4 (GSE) + DW; extrato de gengibre G5 (GE) + DW; G6- Ca (OH) 2 + CHX; G7 ­ GSE + CHX; e G8-GE + CHX. A atividade antimicrobiana foi avaliada por contagem de unidades formadoras de colônias (UFCs) e as alterações de cor dentinária foram avaliadas por espectrofotometria digital. Os dados foram analisados estatisticamente por ANOVA one-way, seguida pelo teste post hoc de Tukey (avaliação antimicrobiana) e Wilcoxon não paramétrico, seguido pelo teste de Mann- Whitney-U (avaliação da mudança de cor) (α = 0,05). Resultados: a maior redução bacteriana foi observada nos grupos 4, 6, 7 e 8, sem diferença significativa entre eles (p < 0,05). Os grupos 4 e 7 apresentaram as maiores medianas da alteração da cor dentinária (p < 0,05). Conclusão: a adição de CHX melhorou a atividade antimicrobiana da medicação intracanal baseado em GE, sem efeito na medicação intracanal baseado em GSE; além disso, esses protocolos induziram alterações significativas na cor dentinária.(AU)

Efeito do fluxo salivar na rugosidade e conteúdo mineral do esmalte clareado: estudo in situ e in vitro / Effect of salivary flow on bleached enamel roughness and mineral content: an in vitro and in situ study

Este estudo avaliou o efeito do contato com a saliva in vitro e do fluxo salivar normal e reduzido in situ na rugosidade e na composição de cálcio e fósforo do esmalte, após clareamento com peróxido de hidrogênio 35%. Espécimes obtidos de terceiros molares (5 x 5 mm) foram divididos em 5 grupos (n=15), G1: não clareado e não exposto à saliva; G2: clareado e não exposto à saliva; G3: clareado e mantido em saliva natural in vitro, G4: clareado e mantido em saliva humana in situ em voluntários com fluxo salivar normal, G5: clareado e mantido em saliva humana in situ em voluntários com baixo fluxo salivar. A rugosidade (Ra, Rz), a proporção cálcio/fósforo e as porcentagens de cálcio e fósforo do esmalte foram avaliadas, respectivamente, por perfilometria a laser 3D e espectroscopia de energia dispersiva por raios X, antes do clareamento (T1), após o clareamento (T2) e após contato com saliva (T3). A saliva dos participantes foi coletada e o fluxo salivar foi medido para alocação nos grupos 4 e 5. O pH salivar e a capacidade tampão foram avaliados por fitas medidoras.As concentrações de cálcio e fósforo salivar foram determinadas por espectrofotometria de absorbância. Os dados foram analisados por testes não paramétricos para análise entre grupos e entre os tempos. Um modelo de regressão linear foi ajustado para a variável dependente rugosidade do esmaltedos grupos 4 e 5 em T3, considerando as covariáveis fluxo salivar, pH, capacidade tampão e concentração de cálcio e fósforo salivar (p<0,05). Não houve diferença de rugosidade (Ra, Rz) entre grupos em T1 (p>0,05). Em T2, G1 diferiu de todos os grupos. Em T3, G5=G2>G3=G4=G1. Para G1, a rugosidade de T1=T2=T3. Para G2 e G5 T10,05). A rugosidade Ra foi em média 0,14 menor no grupo de fluxo salivar normal comparado ao grupo de fluxo reduzido, enquanto Rz foi em média 1,95 menor no grupo fluxo salivar normal. Conclui-se que o contato com a saliva humana in vitro e com o fluxo salivar normal in situ restabeleceu a rugosidade do esmalte. O baixo fluxo salivar in situ não restabeleceu a rugosidade inicial. O clareamento dentário e o contato com a saliva humana não alteram a proporção cálcio/fósforo e nem suas porcentagens isoladas no esmalte. A recuperação da rugosidade do esmalte clareado foi maior em fluxo salivar normal que em baixo fluxo salivar, independentemente do pH salivar e de sua capacidade tampão.

This study evaluated the effect of saliva in vitro and regular or low salivary flow in situ on roughness, calcium/phosphorus ratio and calcium and phosphorus percentages of the enamel bleached with 35% hydrogen peroxide. Seventy-five specimens of third molars were divided in 5 groups, G1: Not bleached and not exposed to saliva; G2: Bleached and not exposed to saliva; G3: Bleached and stored in natural saliva in vitro, G4: Bleached and exposed to human saliva in situ in normal salivary flow participants, G5: Bleached and exposed to human saliva in situ in low salivary flow participants. Roughness (Ra, Rz) was evaluated with a 3D laser non-contact profilometer. Calcium/phosphorus ratio and calcium and phosphorus percentages were determined with energy- dispersive X-Ray spectrophotometry. These evaluations were performed before bleaching (T1), after bleaching (T2) and after the contact with saliva (T3). Participants saliva was collected and salivary flow was measured for their allocation in groups 4 and 5. Salivary pH and buffering capacity were evaluated with measuring tapes. Salivary calcium and phosphorus concentrations were determined by absorbance spectrophotometry. Data were analyzed by nonparametric tests for the analysis between groups and times. A model of linear regression was adjusted for the dependent variable enamel roughness of groups 4 and 5 in T3, considering the covariables salivary flow, pH, buffering capacity and salivary calcium and phosphorus concentration (p<0.05). Roughness was similar among groups in T1. In T2, G1 differed from all groups. In T3, G5=G2>G3=G4=G1. For G1, roughness of T1=T2=T3. For G2 and G5 T10.05), nor between the moments of evaluation T1, T2 and T3 (p>0.05). Ra and Rz were, respectively, 0.14 and 1.95 lower with normal salivary flow than reduced salivary flow. It was concluded that the contact with the human saliva in vitro and normal salivary flow in situ reestablished the enamel roughness to the original values, but the low salivary flow did not. Dental bleaching and the contact with human saliva cannot modify calcium/phosphorus ratio nor their isolated percentages. Recovery of bleached enamel roughness was higher in normal salivary flow than low salivary flow, regardless of saliva pH and buffering capacity.

Effect of Thermocycling on the Colour Stability of Aesthetic Restorative Materials: An in-vitro Spectrophotometric Analysis

Abstract Objective: To compare the color stability of Cention N, Fuji IX GP Extra, and Fuji IX GP after thermocycling. Material and Methods: Ten discs of each material of dimension 10 x 1 mm were prepared using a split mold. The preparations of the specimens were done according to the powder/liquid ratio as recommended by the manufacturers [4.6:1, 3.4:1 and 3.6:1 for the groups I, II, and III, respectively]. After setting, the samples were retrieved, and the thickness of each specimen was measured using a micrometer at five different locations. The specimens with variations in thickness, porosity or cracks were discarded and thus not included in the study. The selected specimens were stored in distilled water for 24 hours prior to testing. The prepared specimens were thermocycled at 5°C and 55°C, with a dwell time of 15 seconds for 250 or 500 cycles. Subsequently, the color parameters of the discs were measured using a spectrophotometer. The data were analyzed using two way ANOVA test, and a p-value <0.001 was considered. Results: Thermocycling resulted in changes in the color of both Glass Ionomer cement and Cention N (p<0.001). Among the materials tested, Cention N showed superior color stability. Conclusion: Cention N exhibited better color stability compared to Glass ionomer cements.

Conhecendo a terapia clareadora: efeito do local de aplicação e do volume de gel clareador na alteração cromática e sensibilidade pós-operatória: estudo clínico randomizado / Knowing the whitening therapy: effect of the application site and the volume of whitening gel on the chromatic alteration and postoperative sensitivity: randomized clinical trial

Embora o sucesso do clareamento dental tenha sido considerado dependente da dosagem utilizada, este procedimento ainda é cercado de importantes lacunas no que se refere à posologia utilizada e a forma de aplicação dos produtos clareadores. O objetivo deste estudo foi avaliar clinicamente o efeito do posicionamento do gel clareador e a influência de seu volume na alteração cromática e sensibilidade pósoperatória. Para o estudo referente ao posicionamento do gel clareador, trinta pacientes foram selecionados e alocados em três grupos (n=10): GI-aplicação na metade cervical, GII- aplicação na metade incisal, GIII- aplicação em toda a face vestibular. A quantidade e o tempo de aplicação do gel Peróxido de Hidrogênio a 35% foram padronizados. A análise de cor foi realizada pelo ΔE e WID (índice de clareamento), utilizando os valores obtidos pelas leituras realizadas em espectrofotômetro digital. As leituras foram realizadas nas regiões cervical e incisal dos dentes. A sensibilidade espontânea foi avaliada por questionário e a sensibilidade provocada através da análise termosensorial (TSA). As análises foram realizadas em 5 tempos: baseline, após 1º sessão clareadora (S), 2ºS e 3ºS e 14 dias após o término do clareamento. Os dados foram analisados pelo modelo de regressão linear com efeitos mistos e pós-teste por contrastes ortogonais (p< 0,05). Pode-se observar que, em relação à alteração cromática, apesar da região incisal ser momentaneamente favorecida pela aplicação do gel, ao final do tratamento, a restrição do local de aplicação à região cervical ou incisal proporcionaram resultados semelhantes aos obtidos quando o gel foi aplicado em toda a face vestibular. Quanto à sensibilidade, apenas o grupo que recebeu gel clareador na porção cervical apresentou sensibilidade espontânea. Já na análise termosensorial, o grupo que recebeu gel na face vestibular exerceu menor influência no limiar de sensação térmica. Paralelamente, no segundo estudo, em que se avaliou a influência do volume de gel clareador, os trinta pacientes foram alocados em três grupos: GI- 0,025mL, GII-0,05mL, GIII-0,10mL, e receberam o produto apenas nos caninos inferiores (n=10). A análise da alteração cromática foi realizada utilizando um espectrofotômetro digital portátil, sendo calculados os valores de ΔE, ΔL*, Δa*, Δb*, bem como o índice de clareamento (WID). A sensibilidade espontânea foi avaliada por aplicação de questionário e a sensibilidade provocada através da análise termosensorial. As análises foram realizadas em 5 tempos: baseline, após 1º, 2º e 3º sessões clareadoras e 14 dias após o término. Os dados foram analisados pelos testes Anova dois fatores com medidas repetidas e pós-teste de Tukey (p< 0,05). Observouse que o ΔE e o ΔL* foram semelhantes entre os grupos ao final da terapia clareadora. Os valores de Δa*, Δb*, bem com o WID foram mais intensos no grupo que recebeu 0,10mL, que também apresentou a maior sensibilidade espontânea e estimulada. Assim, através dos dois estudos realizados, pode-se concluir que ao final do tratamento, a alteração cromática independe do local de aplicação do gel clareador, entretanto, a região incisal, apresenta saturação cromática mais rápida que a região cervical. Constatou-se também que quanto maior o volume, maior a resposta clareadora nas coordenadas especificas e no índice de clareamento, entretanto, não apresentando diferença na alteração cromática e na luminosidade analisada. Já a sensibilidade dental foi mais intensa quando a aplicação do gel foi concentrada na região cervical, sendo também marcadamente proporcional ao volume empregado. Com isso, em relação ao grupo dental analisado, a redução do posicionamento do gel clareador para a incisal e a utilização de um volume intermediário (0,05mL), proporcionaram efeitos positivos para a alteração cromática e redução da resposta de sensibilidade(AU)

Although the success of tooth whitening was considered to be dependent on the dosage used, this procedure still has important gaps with regard to the dosage used and the form of application of the whitening products. The aim of this study was to evaluate clinically the effect of the positioning of the bleaching gel and the influence of its volume on the chromatic alteration and on the postoperative sensitivity. For the study of the positioning of the bleaching gel, thirty patients were selected and allocated into three groups (n = 10): GI- application on the cervical half, GII- application on the incisal half, GIII- application on the entire buccal surface. The amount and time of application of the 35% hydrogen peroxide gel were standardized. The color analysis was performed by ΔE and WID (lightening index), using the values obtained in the readings performed on a digital spectrophotometer. The readings were made in the cervical and incisal regions of the teeth. Spontaneous sensitivity was assessed using a questionnaire and the sensitivity caused by thermo-sensory analysis (TSA). The analyzes were carried out in 5 stages: baseline, after the 1st whitening session (S), 2ºS and 3ºS and 14 days after the end of the whitening. The data were analyzed using the linear regression model with mixed effects and post-test using orthogonal contrasts (p < 0.05). It can be seen that, regarding the chromatic alteration, although the incisal region is momentarily favored by the application of the gel, at the end of the treatment the restriction of the application site to the cervical or incisal region provided results similar to those obtained when the gel was applied throughout the vestibular face. As for sensitivity, only the group that received whitening gel in the cervical portion had spontaneous sensitivity. In the thermosensory analysis, the group that received gel on the vestibular face had less influence on the threshold of thermal sensation. In parallel, in the second study, in which the influence of the volume of the bleaching gel was evaluated, the thirty patients were allocated into three groups: GI-0.025mL, GII0.05mL, GIII-0.10mL, and received the product only in lower canines (n = 10). The chromatic alteration analysis was performed using a portable digital spectrophotometer, being calculated the values of ΔE, ΔL *, Δa *, Δb *, as well as the bleaching index (WID). Spontaneous sensitivity was assessed by applying a questionnaire and sensitivity by thermo-sensory analysis. The analyzes were carried out in 5 stages: baseline, after 1st, 2nd and 3rd whitening sessions and 14 days after the end. Data were analyzed using two-way ANOVA tests with repeated measures and Tukey's post-test (p < 0.05). It was observed that ΔE and ΔL * were similar between the groups at the end of the bleaching therapy. The values of Δa *, Δb *, as well as the WID were more intense in the group that received 0.10mL, which also showed the highest spontaneous and stimulated sensitivity. Thus, through the two studies carried out, it can be concluded that at the end of the treatment the chromatic alteration does not depend on the application site of the whitening gel, however, the incisal region, presents chromatic saturation faster than the cervical region. It was also found that the greater the volume, the greater the bleaching response in the specific coordinates and in the bleaching index, however, showing no difference in the chromatic alteration and in the analyzed luminosity. The tooth sensitivity was more intense when the application of the gel was concentrated in the cervical region, being also markedly proportional to the volume used. Thus, in relation to the analyzed dental group, the reduction of the positioning of the bleaching gel to the incisal and the use of an intermediate volume (0.05mL), provided positive effects for the chromatic alteration and reduction of the sensitivity response(AU)

Effect of violet LED light on in-office bleaching protocols: a randomized controlled clinical trial

Abstract Objective This study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). Methodology A total of 100 patients were divided into five groups (n=20): LED, LED/CP, CP, LED/HP and HP. Colorimetric evaluation was performed using a spectrophotometer (ΔE, ΔL, Δa, Δb) and a visual shade guide (ΔSGU). Calcium (Ca)/phosphorous (P) ratio was quantified in the enamel microbiopsies. Measurements were performed at baseline (T 0 ), after bleaching (T B ) and in the 14-day follow-up (T 14 ). At each bleaching session, a visual scale determined the absolute risk (AR) and intensity of tooth sensitivity (TS). Data were evaluated by one-way (ΔE, Δa, ΔL, Δb), two-way repeated measures ANOVA (Ca/P ratio), and Tukey post-hoc tests. ΔSGU and TS were evaluated by Kruskal-Wallis and Mann-Whitney, and AR by Chi-Squared tests (a=5%). Results LED produced the lowest ΔE (p<0.05), but LED/HP promoted greater ΔE, ΔSGU and Δb (T 14 ) than HP (p<0.05). No differences were observed in ΔE and ΔSGU for LED/CP and HP groups (p>0.05). ΔL and Δa were not influenced by LED activation. After bleaching, LED/CP exhibited greater Δb than CP (p>0.05), but no differences were found between these groups at T 14 (p>0.05). LED treatment promoted the lowest risk of TS (16%), while HP promoted the highest (94.4%) (p<0.05). No statistical differences of risk of TS were found for CP (44%), LED/CP (61%) and LED/HP (88%) groups (p>0.05). No differences were found in enamel Ca/P ratio among treatments, regardless of evaluation times. Conclusions Violet LED alone produced the lowest bleaching effect, but enhanced HP bleaching results. Patients treated with LED/CP reached the same efficacy of HP, with reduced risk and intensity of tooth sensitivity and none of the bleaching protocols adversely affected enamel mineral content.

Influence of the composition and shades of ceramics on light transmission and degree of conversion of dual-cured resin cements

Abstract Objective Since the transmittance of ceramics can influence the degree of conversion (DC) of resin cements, ceramics composition and shade should be considered in the selection of resin cement. This in vitro study aimed to evaluate the effect of the transmittance of different composition, opacities and shades of ceramics on the degree of conversion of two dual-cured resin cements. Methodology Sixty discs were prepared from low translucency (LT) and medium opacity (MO) lithium disilicate ceramic, and zirconia ceramic (Z). Each group was subdivided into 5 subgroups (n=4) in shades A2, A3.5, B2, C2 and D3. The transmittance measurement was performed in a spectrophotometer. The Variolink II and Rely X U200 resin cements were photoactivated by LED (1400 mW/cm2) for 40 s through the ceramic discs and without the discs (control group). The DC was measured with infrared FTIR spectroscopy, immediately after light activation. Data were analyzed with Kruskall-Wallis and one-way ANOVA, following post-hoc comparisons by Tukey test and Pearson's correlation test (P<0.05). Results LT ceramic exhibited higher transmittance values compared to MO and Z ceramics. LTA2 and LTB2 showed statistically higher transmittance values compared to MOA2, MOA3.5 and ZA3.5. For Variolink II, the ceramic interposition did not influence the DC, since there were no statistical differences between groups with ceramic interposition and the control group. For Rely X U200 cement, the interposition of some ceramics types/shades (LTA3.5, MOA2, MOA3.5 and ZA3.5) significantly decreased the DC values compared to control group. A positive correlation was found between the ceramic transmittance and DC values of both tested cements. Conclusions. The transmittance and DC values of the cements were influenced by composition and shades of the ceramics. The higher the transmittance of ceramics, the higher the DC values for both cements.

Effects of in-office bleaching agent combined with different desensitizing agents on enamel

Abstract Objective: To analyze color change, microhardness and chemical composition of enamel bleached with in-office bleaching agent with different desensitizing application protocols. Materials and Methods: One hundred and seventeen polished anterior human enamel surfaces were obtained and randomly divided into nine groups (n = 13). After recording initial color, microhardness and chemical composition, the bleaching treatments were performed as G1: Signal Professional White Now POWDER&LIQUID FAST 38% Hydrogen peroxide(S); G2: S+Flor Opal/0.5% fluoride ion(F); G3: S+GC Tooth Mousse/Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) paste(TM); G4: S+UltraEZ/3% potassium nitrate&0.11% fluoride(U); G5: S+Signal Professional SENSITIVE PHASE 1/30% Nano-Hydroxyapatite (n-HAP) suspension(SP); G6: S-F mixture; G7: S-TM mixture; G8: S-U mixture; G9: S-SP mixture. Color, microhardness and chemical composition measurements were repeated after 1 and 14 days. The percentage of microhardness loss (PML) was calculated 1 and 14 days after bleaching. Data were analyzed with ANOVA, Welch ANOVA, Tukey and Dunnett T3 tests (p<0.05). Results: Color change was observed in all groups. The highest ΔE was observed at G7 after 1 day, and ΔE at G8 was the highest after 14 days (p<0.05). A decrease in microhardness was observed in all groups except G6 and G7 after 1 day. The microhardness of all groups increased after 14 days in comparison with 1 day after bleaching (p>0.05). PML was observed in all groups except G6 and G7 after bleaching and none of the groups showed PML after 14 days. No significant changes were observed after bleaching at Ca and P levels and Ca/P ratios at 1 or 14 days after bleaching (p>0.05). F mass increased only in G2 and G6, 1 day after bleaching (p<0.05). Conclusions: The use of desensitizing agents containing fluoride, CPP-ACP, potassium nitrate or n-HAP after in-office bleaching or mixed in bleaching agent did not inhibit the bleaching effect. However, they all recovered microhardness of enamel 14 days after in-office bleaching.