Longitudinal bond strength of a universal adhesive and chemical dentin characterization under different acid etching protocols.

OBJECTIVE: This study aimed to analyze the longitudinal bond strength of a universal adhesive and chemically characterize the dentin substrate under different acid etching protocols. METHODOLOGY: Dentin samples were etched with polyacrylic acid 25% (PAA) for 10 seconds (n=3) and phosphoric acid 32% (PA) for 15 seconds (n=3) and analyzed by Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR) before and after treatment. For collagen degradation, samples (n=12) were divided into 3 groups: PAA, PA, and Deionized water (control), and analyzed by the quantity of solubilized type I collagen C-terminal cross-linked telopeptides and solubilized C-terminal peptide in relation to total protein concentration (ICTPtp and CTXtp) and by their ultimate tensile strength (UTS). For the adhesive interface analysis, dentin samples (n=72) were divided into 3 groups: PAA, PA, and Self-etch (SE), and subdivided into 2 groups: 24 h (baseline) and 1 year. The following tests were performed: microtensile bond strength (µTBS) (n=48), scanning electron microscopy (SEM) (n=12), and nanoleakage (n=12). RESULTS: The FTIR of PAA showed lower reduction of the peaks in the phosphate group when compared to PA. For ICTPtp, PA showed a significantly higher value. For CTXtp, PA and PAA groups failed to statically differ from each other. UTS was significantly lower for PA. For µTBS, storage time significantly affected bond strength. The results were unaffected by the etching protocol. For SEM, after 1 year, PA had little evidence of degradation in the upper third of the adhesive interface in comparison to the other groups. Nanoleakage showed no considerable silver impregnation after 1 year in the SE group. CONCLUSION: The use of PAA prior to a universal adhesive (when compared to PA) represents a less aggressive type of etching to dentin. However, self-etching still seems to be the best option for universal adhesive systems that have functional monomers in their composition.

BoneTape: A novel osteosynthetic device for the stabilization of zygomatic fractures.

BACKGROUND: The study aims to assess the safety and effectiveness of BoneTape™, a new resorbable bone fixation device, using a zygomatic fracture model in rabbits. METHODS: The study followed BoneTape™ samples and control (sham) groups over 2-, 6-, and 12-week periods post-zygomaticomaxillary (ZM) osteotomy and zygomaticofrontal (ZF) disarticulation. The osteotomized segments were analyzed for bone healing, inflammatory response, and tissue healing. µCT imaging and histological analysis were used to examine the axial alignment, offset, and quality of new bone formation. RESULTS: BoneTape™ samples demonstrated enhanced maintenance of the initial intraoperative positioning, reduced axial offset, and better alignment when compared with the control group, enabling stable bone healing under physiological loading conditions. Complete union was observed at 12-weeks in both groups. The BoneTape™ group experienced minimal immune and tissue reactions, classically associated with wound healing, and showed an increased number of giant cells at 6 and 12-weeks. CONCLUSION: BoneTape™ represents a promising advancement in osteosynthesis, demonstrating efficacy in maintaining stable zygomatic reconstruction and eliciting minimal immune response in a rabbit model. This study introduces BoneTape™ as a disruptive solution specifically designed for clinical application in cranio-maxillofacial fracture fixation, with the potential to eliminate the use of over-engineered solutions while offering benefits such as ease of application and fewer biologically disruptive steps.

Longitudinal bond strength of a universal adhesive and chemical dentin characterization under different acid etching protocols

Abstract Objective This study aimed to analyze the longitudinal bond strength of a universal adhesive and chemically characterize the dentin substrate under different acid etching protocols. Methodology Dentin samples were etched with polyacrylic acid 25% (PAA) for 10 seconds (n=3) and phosphoric acid 32% (PA) for 15 seconds (n=3) and analyzed by Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR) before and after treatment. For collagen degradation, samples (n=12) were divided into 3 groups: PAA, PA, and Deionized water (control), and analyzed by the quantity of solubilized type I collagen C-terminal cross-linked telopeptides and solubilized C-terminal peptide in relation to total protein concentration (ICTPtp and CTXtp) and by their ultimate tensile strength (UTS). For the adhesive interface analysis, dentin samples (n=72) were divided into 3 groups: PAA, PA, and Self-etch (SE), and subdivided into 2 groups: 24 h (baseline) and 1 year. The following tests were performed: microtensile bond strength (μTBS) (n=48), scanning electron microscopy (SEM) (n=12), and nanoleakage (n=12). Results The FTIR of PAA showed lower reduction of the peaks in the phosphate group when compared to PA. For ICTPtp, PA showed a significantly higher value. For CTXtp, PA and PAA groups failed to statically differ from each other. UTS was significantly lower for PA. For μTBS, storage time significantly affected bond strength. The results were unaffected by the etching protocol. For SEM, after 1 year, PA had little evidence of degradation in the upper third of the adhesive interface in comparison to the other groups. Nanoleakage showed no considerable silver impregnation after 1 year in the SE group. Conclusion The use of PAA prior to a universal adhesive (when compared to PA) represents a less aggressive type of etching to dentin. However, self-etching still seems to be the best option for universal adhesive systems that have functional monomers in their composition.

Insights on the role of cytokines in carious lesions / Insights sobre o papel das citocinas em lesões cariosas

Objetivo: A resposta imune da dentina-polpa à patogênese da cárie ainda é pouco compreendida devido à complexa interação dos processos envolvidos. O objetivo desta revisão foi explorar o papel das citocinas e sua relevância na patogênese da cárie dental. Resultados: A cárie dentária pode resultar em uma resposta inflamatória do hospedeiro na polpa dental, caracterizada pelo acúmulo de células inflamatórias levando à liberação de citocinas inflamatórias como, Interleucina-4 (IL-4), Interleucina (IL-6), Interleucina-8 (IL-8) e fator de necrose tumoral­α(TNF-α). IL-4 parece estar correlacionada com a profundidade das lesões cariosas; IL-6 está fortemente correlacionada com a doença cárie e é considerada um potente biomarcador; IL-8 pode ser um potente biomarcador tanto para cárie quanto para outras alterações presentes na polpa e sua liberação está correlacionada com TNF-α e IL-6; TNF-α desempenha um papel importante não apenas na progressão da cárie, mas também em outros processos patológicos. Conclusao: Mediadores específicos têm um grande potencial para servir como biomarcadores quanto à presença e progressão da doença cárie, o que incita a necessidade de mais investigações nesse campo (AU).

Objectives: The dentin-pulp immune response to caries pathogenesis is still poorly understood due to the complex interplay of the involving processes. The aim of this review was to explore the role of cytokines and its relevance in the pathogenesis of dental caries. Results: Dental caries can result in a host inflammatory response in the dental pulp, characterized by the accumulation of inflammatory cells leading to the release of inflammatory cytokines such as Interleukin-4 (IL-4), Interleukin (IL-6), Interleukin-8 (IL-8) and Tumor necrosis factor­ α (TNF- α ). IL-4 seems to be correlated to the depth of carious lesions; IL-6 is strongly correlated to caries disease and is considered a potent biomarker; IL-8 can be a potent biomarker for both caries and other changes present in the pulp and, its release is correlated to TNF- α and IL-6; TNF-α plays an important role not only in caries progression, but also in other pathological processes. Conclusion: Specific mediators have a great potential to serve as biomarkers alluding to the presence and progress of caries disease, urging further investigations in the field (AU)

Effect of taxifolin and epigallocatechin-3-gallate on biomineralization potential of stem cells from dental apical papilla.

OBJECTIVE: Considering the variety of pharmacological activities and the potential to mediate biomineralization, the flavonoids taxifolin and epigallocatechin-3-gallate (EGCG) could be explored as biomolecules in scaffolds for regenerative endodontic procedures. The aim of this study was to evaluate the effect of taxifolin and EGCG on the cell viability, differentiation, and expression of biomineralization markers in stem cells from the apical papilla. DESIGN: Stem cells from the apical papilla were exposed to single or continuous treatments with taxifolin at 200, 100 and 50 µM and EGCG at 50, 25 and 12.5 µM for 48 h, 8 and 14 days, in regular or mineralizing media. Cell viability, alkaline phosphatase activity and calcium deposition were analyzed using resazurin, p-nitrophenylphosphate and alizarin-based assays. RESULTS: None of the flavonoid groups affected cell viability at 48 h, however at 8 and 14 days, Taxifolin 200 µM and EGCG 50 µM were cytotoxic. Cells did not express alkaline phosphatase activity when grown in regular medium, even in the presence of flavonoids. Alkaline phosphatase activity and biomineralization potential were higher in cells treated with Taxifolin 50 µM and EGCG 12.5 µM. CONCLUSION: Taxifolin and EGCG exhibited a concentration, time, and therapeutic mode dependent bioactivity on stem cells from the apical papilla. Both flavonoids at the lower concentrations tested exhibited cytocompatibility and increased expression of mineralization markers in the presence of mineralizing agents.

Clinical performance of 6% hydrogen peroxide containing TiO2N nanoparticles activated by LED in varying wavelengths-a randomized clinical trial.

This randomized, controlled, and double-blinded clinical trial evaluated the clinical performance of dental bleaching performed with 6% hydrogen peroxide containing TiO2-N nanoparticles exposed to blue and violet activation lights. Forty volunteers, selected according to the inclusion and exclusion criteria, were randomly distributed into four experimental groups (n = 10): 35% hydrogen peroxide (PH35)-control; 6% hydrogen peroxide (PH6) containing TiO2-N nanoparticles without light activation; PH6 activated with a blue LED (PH6A); and PH6 activated with a violet LED (PH6V). The three bleaching sessions consisted of 3 consecutive 16-min applications of the bleaching agent described for each group. The groups receiving LED activation were exposed to light intermittently every 1 min, with a total exposure time of 8 min in each application. Efficacy was determined by the color variation in the upper central incisors and canines, using reflectance spectroscopy analysis performed by a calibrated evaluator (ICC = 0.83). Tooth sensitivity was characterized according to the presence and intensity (SI) self-recorded in specific forms. The group treated with PH6V was as effective as the control group (PH35), whereas the groups PH6A and PH6 showed lower efficacy. Regardless of the activation, all groups treated with 6% hydrogen peroxide were less likely to cause sensitivity compared to the control group (PH35). The use pf PH6 activated by LED violet resulted in an effective and safe clinical protocol for in-office dental bleaching.Trial registration number: RBR-8pbydg; registration date: 08/29/2017.

Methacrylation of epigallocatechin-gallate for covalent attachment with a dental polymer.

OBJECTIVE: Synthesize novel epigallocatechin-gallate (EGCG) methacrylate monomers with the ability to copolymerize with dental methacrylate resins. METHODS: EGCG was reacted with 1/3 (E33), 2/3 (E67) and 1 (E100) molar equivalents of methacyloyl chloride introducing three degrees of polymerizablility. EGCG-methacrylates were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). E33, E67, E100 and neat EGCG were incorporated into TEGDMA at 0.5-20% ratios (m/m). Copolymers were tested for degree of conversion (%DC), EGCG release, gel content (%GC), degree of swelling (%DS), flexural properties and bacterial viability (Streptococcus mutans, baseline/30-days). Neat TEGDMA and TEGDMA passively loaded with EGCG (E0) were used as controls. Data were analysed by one-way ANOVA, Tukey, and Dunnett's method (α=5%). Two-way ANOVA and Bonferroni were used to investigate factor interaction. RESULTS: FTIR/NMR confirmed synthesis of desired compounds. All of E100 incorporated ratios had %DC similar to TEGDMA. Remaining groups had reduction in %DC at 2% in E0, 10% in E33 and 20% in E67 ratios. EGCG was stable within ECGC-methacrylate copolymers. Release of EGCG from E0 significantly increased with higher EGCG ratios. Except for E100, higher EGCG or EGCG-methacrylate ratios led to decreased %CG and %DS. At baseline, E0 had the lowest bacterial survival rates (1-10% survival) at all ratios compared to E33, E67, E100, and neat TEGDMA. However, E33, E67 and E100 still had statistically lower survival rates (7-53%) compared with neat TEGDMA. After 30-days, all compounds had similar survival rates for all ratios, which were lower than that of neat TEGDMA. SIGNIFICANCE: Demonstration of methacrylate functionalized EGCG- with inherited antibacterial activity for improved restoration longevity.

Blue Covarine Toothpaste versus Office Whitening: Which is the Most Effective on Stained Teeth? / Creme Dental de Blue Covarine Versus Clareamento de Consultório: Qual é o Mais Efetivo em Dentes Pigmentados?

Alternative whitening strategies to hydrogen peroxide have been proposed, such as the inclusion of abrasive and/or pigmented particles in the toothpaste. This study compared the whitening effectiveness of a toothpaste containing Blue Covarine (BC) vs. an in-office whitening treatment using 35% hydrogen peroxide (HP) in teeth stained. Bovine incisors blocks (6.0x6.0x2.0 mm) were stained with green tea (GT), orange soda (OS), or red wine (RW). The samples were randomly assigned into 8 groups (n=15), according to the type of staining and whitening treatment: G1 ­ no staining, BC (Control); G2 ­ no staining, HP (Control); G3 ­ GT, BC; G4 ­ GT, HP; G5 ­ OS, BC; G6 ­ OS, HP; G7 ­ RW, BC; G8 ­ RW, HP. Color change (ΔE), luminosity (L*), green-red axis (a*), and blue-yellow axis (b*) were recorded with spectroscopy at T0 ­ baseline, T1 ­ immediately after toothbrushing or in office tooth whitening, and T2 ­ after the conclusion of the treatments. The whiteness index for dentistry (WID) was calculated. Data were analyzed by two-way repeated measured mixed ANOVA and Bonferroni test (α=0.05). HP showed a better whitening performance (ΔE) (p ≤ 0.042). Otherwise, no effects of the whitening agent were observed (p = 1.000). Data from ΔL, Δa, and Δb showed statistically significant differences for experimental groups (p < 0.001). In the WID analysis, BC and HP had similar effects within control and RW groups. In conclusion, blue covarine toothpaste may be a viable option for extrinsically stained teeth. However, for severe staining, HP-based whitening agents proved to be the most effective treatment strategy. (AU)

Estratégias de clareamento alternativas ao peróxido de hidrogênio têm sido propostas, como a inclusão de partículas abrasivas e/ou pigmentadas nos cremes dentais. Este estudo comparou a eficácia clareadora de um creme dental contendo Blue Covarine (BC) com um tratamento de clareamento em consultório com peróxido de hidrogênio a 35% (HP) em dentes pigmentados. Blocos de incisivos bovinos (6,0x6,0x2,0 mm) foram pigmentados com chá verde (GT), refrigerante de laranja (OS) ou vinho tinto (RW). As amostras foram distribuídas aleatoriamente em 8 grupos (n = 15), de acordo com o tipo de pigmento e tratamento clareador: G1 - sem coloração, CB (Controle); G2 - sem coloração, HP (Controle); G3 - GT, BC; G4 - GT, HP; G5 - OS, BC; G6 - SO, HP; G7 - RW, BC; G8 - RW, HP. Mudança de cor (ΔE), luminosidade (L *), eixo verde-vermelho (a*) e eixo azul-amarelo (b*) foram registrados com espectroscopia em T0 - baseline, T1 - imediatamente após a escovação ou clareamento dental em consultório, e T2 - após a conclusão dos tratamentos. O índice de brancura para odontologia (WID) foi calculado. Os dados foram analisados por ANOVA mista de duas vidas para medidas repetidas e teste de Bonferroni (α = 0,05). HP apresentou melhor desempenho de clareamento (ΔE) (p ≤ 0,042). Os dados de ΔL, Δa e Δb mostraram diferenças estatisticamente significativas para os grupos experimentais (p <0,001). Na análise WID, BC e HP tiveram efeitos semelhantes nos grupos controle e RW. Em conclusão, o creme dental covarine azul pode ser uma opção viável para dentes com coloração extrínseca. No entanto, para manchas graves, os agentes de clareamento à base de HP provaram ser a estratégia de tratamento mais eficaz. (AU)

The effectiveness of glass ionomer cement as a fiber post cementation system in endodontically treated teeth.

This study compared the performance of a glass ionomer (GC Gold Label 1, GIC) as a fiber post cementation system for glass fiber posts with a self-adhesive resin cement (Relyx U200, RUC) and a conventional resin cement system (Scotchbond Muli-Purpose and Relyx ARC, RAC). Thirty endodontically treated canines were randomly divided in three groups (n = 10), according to the fiber post cementation system: (RAC)-Scotchbond Multi-Purpose and Relyx X ARC; (RUC)-Relyx U200 and (GIC)-GC Gold Label 1 Luting & Lining. Rhodamine was incorporated into the cementation system prior to the fiber post cementation. After glass fiber post cementation, roots were incubated in artificial saliva for 6 months. After that, specimens from the cervical, middle, and apical thirds of the post space were prepared and analyzed using a push-out bond strength test and confocal laser microscopy. ANOVA one way and Tukey tests showed that GIC and RUC demonstrated similar push-out bond strength values, independently of the post space third (p > .05); however, values were greater than those shown by RAC (p < .05). For dentin penetrability, GIC and RUC also had similar results (p > 0.05) and lower than RAC (p < 0.05). Inside the root canal, the cementation system using glass ionomer cement (GC Gold Label 1 Luting & Lining) has similar push-out bond strength to the self-adhesive resin cement (Relyx U200) and these were higher than the conventional resin (Relyx ARC), despite its higher dentin penetrability.

Whitening toothpaste containing activated charcoal, blue covarine, hydrogen peroxide or microbeads: which one is the most effective?

The efficacy of whitening toothpastes is questionable and controversial. Clinicians, patients and researchers have expressed concern with whitening toothpastes due to the risk of wearing the dental structure and the potential for disappointment if the advertised cosmetic results are not achieved. OBJECTIVE: This study compared the whitening performance of toothpastes with different whitening technologies after initial and continued use. MATERIAL AND METHODS: Ninety bovine incisors were stained using a concentrated solution of black tea. They were randomly distributed into 6 groups, according to the toothpaste whitening technology: activated charcoal (B&W), blue covarine (WAD), hydrogen peroxide (LWA), microbeads (Oral B 3D White Perfection - 3DW) and optimized abrasives (XW4D). They were compared to a traditional toothpaste without a whitening agent (TA - control). Specimens underwent a brushing machine with controlled pressure, time and temperature. A calibrated examiner measured the color using a VITA-Classical scale before the first brushing cycle (T0), after the first brushing cycle (TI), and after a brushing cycle that simulates continuous use (TCU). Whitening performance was evaluated by the difference of shades (ΔSGU) between T0-TI and T0-TCU timepoints, using the Kruskal-Wallis and Dunn's non-parametric test. The Wilcoxon test was used to evaluate the cumulative effect (α=0.05). RESULTS: Statistically significant differences were observed between toothpastes in both TI and TCU (p<0.05). The time of use also had a significant effect (p<0.05). CONCLUSION: Only WAD and 3DW showed whitening performance after the first use (TI). The greatest whitening performance after continuous use was obtained by WAD, followed by LWA and 3DW. The use of conventional toothpaste (TA) promotes no tooth whitening. CLINICAL RELEVANCE: Microbead abrasives (3DW) and blue covarine (WAD) were the active technology tested that presented the best global tooth whitening performance.

Whitening toothpaste containing activated charcoal, blue covarine, hydrogen peroxide or microbeads: which one is the most effective?

Abstract The efficacy of whitening toothpastes is questionable and controversial. Clinicians, patients and researchers have expressed concern with whitening toothpastes due to the risk of wearing the dental structure and the potential for disappointment if the advertised cosmetic results are not achieved. Objective: This study compared the whitening performance of toothpastes with different whitening technologies after initial and continued use. Material and Methods: Ninety bovine incisors were stained using a concentrated solution of black tea. They were randomly distributed into 6 groups, according to the toothpaste whitening technology: activated charcoal (B&W), blue covarine (WAD), hydrogen peroxide (LWA), microbeads (Oral B 3D White Perfection - 3DW) and optimized abrasives (XW4D). They were compared to a traditional toothpaste without a whitening agent (TA - control). Specimens underwent a brushing machine with controlled pressure, time and temperature. A calibrated examiner measured the color using a VITA-Classical scale before the first brushing cycle (T0), after the first brushing cycle (TI), and after a brushing cycle that simulates continuous use (TCU). Whitening performance was evaluated by the difference of shades (ΔSGU) between T0-TI and T0-TCU timepoints, using the Kruskal-Wallis and Dunn's non-parametric test. The Wilcoxon test was used to evaluate the cumulative effect (α=0.05). Results: Statistically significant differences were observed between toothpastes in both TI and TCU (p<0.05). The time of use also had a significant effect (p<0.05). Conclusion: Only WAD and 3DW showed whitening performance after the first use (TI). The greatest whitening performance after continuous use was obtained by WAD, followed by LWA and 3DW. The use of conventional toothpaste (TA) promotes no tooth whitening. Clinical relevance: Microbead abrasives (3DW) and blue covarine (WAD) were the active technology tested that presented the best global tooth whitening performance.

Functionalized epigallocatechin gallate copolymer inhibit dentin matrices degradation: Mechanical, solubilized telopeptide and proteomic assays.

OBJECTIVES: We investigated the biostability of dentin organic matrices treated with epigallocatechin gallate (EGCG) in comparison to chlorhexidine (CHX), both extracted from functionalized copolymers. METHODS: Copolymers were prepared with bis-GMA:TEGDMA and incorporated with 1% of EGCG or CHX (w/w). Blank copolymers were used as control. Copolymer samples were individually stored in 1mL deionized water to produce copolymer extracts. Dentin matrices were obtained by demineralization of dentin disks in 10% phosphoric acid solution. Matrices were individually treated with 1mL of the copolymer extracts or distilled water for 48h. Collected extracts were analyzed by high-performance liquid chromatography (HPLC) for the presence and quantification of EGCG, CHX, and copolymer by-products. Treated dentin matrices were tested for ultimate tensile strength, gravimetric changes, and swelling ratio. The treatment media were tested for total protein concentration, and dentin protease activity through solubilized telopeptide (ICTP- and CTX-ELISA) assays. The treatment media were also submitted to proteomic analysis. RESULTS: HPLC identified released unreacted copolymer species and showed higher release of CHX compared to EGCG from respective copolymer extracts. EGCG extract inhibited activity of dentin proteolytic enzymes and promoted collagen biomodification observed by the telopeptide assays and in the changes to dentin matrix properties. The proteomic results showed less collagenous peptide hits in the EGCG extract media compared to CHX, and suggest compound-specific dentin protein binding interactions. SIGNIFICANCE: This study demonstrates specific antiproteolytic effect and protein interactions of EGCG copolymer extract directly on dentin. This represents an advancement in dental materials which can impact the clinical procedures.

Color stability of conventional and bulk fill composite resins / Estabilidade cromática de resinas convencionais e resinas bulk fill

ABSTRACT Objective: This study compared the color stability of different dental composite resins after prolonged exposure to a coffee solution. Methods: Sixty-four cylindrical discs (10 mm diameter x 2 mm thickness) were prepared using 8 different dental composite resins (n=8, per group). The specimens were first immersed in artificial saliva for 24 h followed by immersion in a coffee solution for 14 days. The assessment of chromatic variation (ΔE) was performed with the aid of a Vita Easyshade Advanced spectrophotometer (VITA Zahnfabrik, Bad Sackingen, Germany). The color of each specimen was calculated based on the L*, a* and b* coordinates of the CIELab system. Results: Grandio SO had the lowest average chromatic variation (ΔE=7.77) after immersion in coffee solution. Durafill VS, Grandio and Z350 XT (ΔE=8.58; ΔE=9.52; ΔE=10.39, respectively) showed similar chromatic variation, with no statistical difference in relation to Grandio SO. However, the other dental composite resins evaluated showed statistically higher values of ΔE compared to Grandio SO, and Enamel HRi (ΔE=20.56) demonstrated the highest chromatic variation. Conclusion: The Bulk Fill and hybrid composite resins from the same manufacturer (Micerium, Avegno, Italy) showed greater chromatic variation than the other composite resins tested. Grandio SO (Voco, Cuxaven, Germany) had the lowest ΔE variation.

RESUMO Objetivo: Comparar diferentes resinas compostas em relação á estabilidade de cor após exposição prolongada em solução de café. Métodos: Sessenta e quatro discos cilíndricos (10mm x 2mm) foram confeccionados a partir de 8 diferentes marcas comerciais de compósitos (n= 8 por grupo); os espécimes foram imersos em saliva artificial, e posteriormente em café, sendo por conseguinte feita a avaliação da variação cromática (ΔE), utilizando espectrofotômetro Vita Easyshade Advanced (VITA Zahnfabrik, Bad Sackingen, Germany). O padrão de cada espécime foi medido examinando as coordenadas L*, a* e b* do sistema CIELab. Resultados: A resina composta Grandio SO apresentou a menor média de variação cromática (ΔE= 7,77) após a imersão em solução de café. Semelhantemente, a variação cromática das resinas compostas Durafill VS, Grandio e Z350 XT (ΔE=8,58; ΔE=9,52; ΔE=10.39) que não apresentaram diferença estatística. Todavia, as demais resinas compostas avaliadas apresentaram valores estatisticamente maiores de ΔE em relação a resina Grandio SO, sendo que a resina Enamel HRi (ΔE= 20,56) apresentou a maior variação cromática registrada. Conclusão: As resinas da categoria bulk fill e as resinas híbridas produzidas pelo mesmo fabricante (Micerium, Avegno, Itália) tiveram alterações cromáticas superiores às demais resinas testadas sendo que a resina GrandioSO (Voco, Cuxaven, Alemanha) foi a que apresentou menor alteração de ∆E.

New Parameter for In-Office Dental Bleaching.

Dental bleaching is considered a conservative and biologically safe treatment for discolored teeth. Despite this, one of the major undesirable effects of bleaching is dentin sensitivity which may occur during and after treatment. To address these sensitivity issues, new dental bleaching preparations with lower concentrations of hydrogen peroxide (H2O2) have recently been introduced to the market. This paper presents a clinical case report of a 20-year-old female patient admitted to the Araraquara Dental School, UNESP, Brazil. The patient underwent dental bleaching using one of the new products with reduced hydrogen peroxide concentration, Lase Peroxide Lite 6%, a 6% H2O2 gel containing titanium oxide nanoparticles doped with nitrogen (6% H2O2/N-doped TiO2).

Optical Dental Whitening Efficacy of Blue Covarine Toothpaste in Teeth Stained by Different Colors.

OBJECTIVE: Evaluate the immediate and cumulative optical whitening efficacy of a blue covarine toothpaste. MATERIALS AND METHODS: 180 bovine tooth specimens with similar shade (ΔE < 3.5) were staining of different beverage: black tea(BT), green tea (GT), red wine (RW), orange soda (OS), and brazilian açai juice (AJ), and then submitted to tooth brushing with a blue covarine toothpaste (Op) or a control abrasive toothpaste (Ab). The whitening effect was evaluated at baseline (B), after staining (S), after 1 day (1D) and 7 days of cumulative use of toothpastes (7D). The color shade chances were assessment by Vita Easyshade reflectance spectroscope and the data of CIELab color coordinates (L*, a*, and b*), color difference (ΔE) and the whiteness index optimized (WIO), were analyzed by two-way mixed analysis of variance (ANOVA) for repeated measures and Bonferroni-corrected t-tests (α = 0.05). RESULTS: The analysis showed statistically significant differences before and after staining by colored beverages (p < 0.05), but no differences were found due to the action of toothpaste (p > 0.05), in the CIELab coordinates, ΔE and WIO index. CONCLUSIONS: The use of toothpastes (Op or Ab) reduced the dental staining caused by different colored beverage, but the whitening effect of blue covarine toothpaste could not be confirmed (p > 0.05).

Does a toothpaste containing blue covarine have any effect on bleached teeth? An in vitro, randomized and blinded study.

The objective of this study was to analyze the effect of bleaching toothpastes, both conventional and those containing the new whitening agent Blue Covarine, on teeth previously bleached by conventional techniques (in-office and at-home). Squared bovine enamel/dentin blocks (6.0 x 6.0 x 2.0 mm) were randomly distributed in 6 groups (n = 15), according to the technique used to bleach them (in-office: HP35%; at-home: PC10%) and the type of bleaching toothpaste (none: control; Blue Covarine containing: BC; and without Blue Covarine: NBC). Experimental groups denominated HP35%, HP35%BC and HP35%NBC received in-office tooth bleaching before toothbrushing, and groups PC10%, PC10%BC and PC10%NBC were subjected to at-home tooth bleaching prior to toothbrushing. After bleaching treatment, groups HP35%BC, PC10%BC, HP35%NBC and PC10%NBC underwent daily tooth brushing in a brushing machine for 3 minutes (150 strokes/min, with a load of 375 g). Tooth color alteration was measured by reflectance spectroscopy (Vita EasyShade, Vident, Brea, CA, USA) at: T0 (baseline) - after in-office or at-home bleaching treatment; T1 - immediately after tooth brushing; T2 - 7 days and T3 - 14 days after tooth brushing. Data was analyzed by repeated measures mixed ANOVA and the Bonferroni post hoc test, with a significance level of 5%. Statistically significant differences were found between different experimental groups, evaluation times and for the interaction between them (p < 0.001). Tooth brushing using either bleaching toothpaste (conventional or with Blue Covarine) showed no color alteration on teeth previously bleached by in-office and at-home tooth bleaching. The use of bleaching toothpastes on previously bleached teeth did not produce a color alteration.

A novel approach for in-office tooth bleaching with 6% H2O2/TiO_N and LED/laser system-a controlled, triple-blinded, randomized clinical trial.

UNLABELLED: The purpose of this randomized, parallel, triple-blinded clinical trial was to compare efficacy and tooth sensitivity (TS) after use of an in-office bleaching agent of 6% hydrogen peroxide containing nanoparticles of nitrogen-doped titanium oxide (HP6) vs. 35% hydrogen peroxide (HP35). Forty-eight volunteers were randomly divided either a HP6 or HP35. Two clinical sessions were performed with an interval of 7 days between them for each group. In each session, two consecutive applications of each bleaching agent were performed and activated by a hybrid LED/laser light. Efficacy was determined by color alteration (ΔE), recorded with reflectance spectroscopy. It was assessed at baseline and after the first and second bleaching session. TS was characterized according to occurrence, intensity, duration, and type. Efficacy was analyzed by repeated measures analysis of variance (ANOVA) and post hoc Bonferroni test, and TS was analyzed by means of chi(2) test (α = 0.05). For HP35, highest and significant values of ΔE were found after bleaching when compared to HP6 (p = 0.002). However, HP35 showed a significantly higher occurrence of TS than HP6 (p = 0.008). Also, intensity and duration were higher in HP35. The majority of volunteers classified the type experienced in their sensitivity in the form of a "shock." The use of HP6 despite reducing efficacy when compared to an in-office bleaching in higher concentration (35%) produced less tooth sensitivity. CLINICAL RELEVANCE: In terms of tooth sensitivity, the use of lower concentrations of in-office bleaching should be the first choice, suggesting greater biocompatibility and safety compared to a conventional HP35.

Antimicrobial Activity of Amphiphilic Triazole-Linked Polymers Derived from Renewable Sources.

Conventional engineered polymers are strong, stable, and can interact desirably within the human body in implants and medical devices. However, bacterial colonization of medical devices and implants constructed from these materials results in numerous hospital acquired infections (HAI) and deaths each year. Polytriazole based plastics containing triazole rings and fatty acid derivatives have been synthesized from biological sources without catalysts or solvents. In this study, three amphiphilic polytriazoles with varying triazole density and hydrophilic/hydrophobic segments demonstrated broad spectrum, contact antimicrobial properties against both Gram positive and negative bacteria. SEM analysis of bacteria killed by these polymers evidence membrane damage, indicating that these polymers act by direct contact with bacterial membranes. Surface hydrophobicity of these polymers increased with increasing triazole group density, which also improved the antimicrobial efficacy. This work demonstrates that amphiphilic polytriazoles have antimicrobial properties and that future utilization of triazole modified polymers may produce self-sterilizing materials which resist bacterial contamination and formation of antibiotic resistant organisms, ideal characteristics for medically relevant biomaterials.

Does a toothpaste containing blue covarine have any effect on bleached teeth? An in vitro, randomized and blinded study

Abstract The objective of this study was to analyze the effect of bleaching toothpastes, both conventional and those containing the new whitening agent Blue Covarine, on teeth previously bleached by conventional techniques (in-office and at-home). Squared bovine enamel/dentin blocks (6.0 x 6.0 x 2.0 mm) were randomly distributed in 6 groups (n = 15), according to the technique used to bleach them (in-office: HP35%; at-home: PC10%) and the type of bleaching toothpaste (none: control; Blue Covarine containing: BC; and without Blue Covarine: NBC). Experimental groups denominated HP35%, HP35%BC and HP35%NBC received in-office tooth bleaching before toothbrushing, and groups PC10%, PC10%BC and PC10%NBC were subjected to at-home tooth bleaching prior to toothbrushing. After bleaching treatment, groups HP35%BC, PC10%BC, HP35%NBC and PC10%NBC underwent daily tooth brushing in a brushing machine for 3 minutes (150 strokes/min, with a load of 375 g). Tooth color alteration was measured by reflectance spectroscopy (Vita EasyShade, Vident, Brea, CA, USA) at: T0 (baseline) - after in-office or at-home bleaching treatment; T1 - immediately after tooth brushing; T2 - 7 days and T3 - 14 days after tooth brushing. Data was analyzed by repeated measures mixed ANOVA and the Bonferroni post hoc test, with a significance level of 5%. Statistically significant differences were found between different experimental groups, evaluation times and for the interaction between them (p < 0.001). Tooth brushing using either bleaching toothpaste (conventional or with Blue Covarine) showed no color alteration on teeth previously bleached by in-office and at-home tooth bleaching. The use of bleaching toothpastes on previously bleached teeth did not produce a color alteration.

Can a bleaching toothpaste containing Blue Covarine demonstrate the same bleaching as conventional techniques? An in vitro, randomized and blinded study

ABSTRACT Objective The purpose of this in vitro study was to compare the efficacy of a bleaching toothpaste containing Blue Covarine vs. conventional tooth bleaching techniques using peroxides (both in-office and at-home). Material and Methods Samples were randomly distributed into five experimental groups (n=15): C - Control; BC – Bleaching toothpaste containing Blue Covarine; WBC – Bleaching toothpaste without Blue Covarine; HP35 - In-office bleaching using 35% hydrogen peroxide; and CP10 – At-home bleaching with 10% carbamide peroxide. The dental bleaching efficacy was determined by the color difference (ΔE), luminosity (ΔL), green-red axis (Δa), and blue-yellow axis (Δb). The CIELab coordinates were recorded with reflectance spectroscopy at different times: T0 - baseline, T1 – immediately after bleaching, T2 - 7 days, T3 - 14 days, and T4 - 21 days after the end of treatments. Data were analyzed by a repeated measures mixed ANOVA and post hoc Bonferroni test, with a significance level of 5%. Results No significant differences were found between the treatment groups C, BC, and WBC. The groups HP35 and CP10 showed significantly higher whitening efficacy than groups C, BC, and WBC. Conclusions There were no significant differences in the whitening efficacy between a Blue Covarine containing toothpaste, a standard whitening toothpaste, and a control. Neither of the whitening toothpastes tested were as effective as in-office or at-home bleaching treatments.