Neurosensory analysis of tooth sensitivity during at-home dental bleaching: a randomized clinical trial

Abstract Objective The objective of this study was to evaluate dental sensitivity using visual analogue scale, a Computerized Visual Analogue Scale (CoVAS) and a neurosensory analyzer (TSA II) during at-home bleaching with 10% carbamide peroxide, with and without potassium oxalate. Materials and Methods Power Bleaching 10% containing potassium oxalate was used on one maxillary hemi-arch of the 25 volunteers, and Opalescence 10% was used on the opposite hemi-arch. Bleaching agents were used daily for 3 weeks. Analysis was performed before treatment, 24 hours later, 7, 14, and 21 days after the start of the treatment, and 7 days after its conclusion. The spontaneous tooth sensitivity was evaluated using the visual analogue scale and the sensitivity caused by a continuous 0°C stimulus was analyzed using CoVAS. The cold sensation threshold was also analyzed using the TSA II. The temperatures obtained were statistically analyzed using ANOVA and Tukey's test (α=5%). Results The data obtained with the other methods were also analyzed. 24 hours, 7 and 14 days before the beginning of the treatment, over 20% of the teeth presented spontaneous sensitivity, the normal condition was restored after the end of the treatment. Regarding the cold sensation temperatures, both products sensitized the teeth (p<0.05) and no differences were detected between the products in each period (p>0.05). In addition, when they were compared using CoVAS, Power Bleaching caused the highest levels of sensitivity in all study periods, with the exception of the 14th day of treatment. Conclusion We concluded that the bleaching treatment sensitized the teeth and the product with potassium oxalate was not able to modulate tooth sensitivity.

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

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

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.

Effect of sodium ascorbate on the bond strength of silorane and methacrylate composites after vital bleaching

We investigated the effect of sodium ascorbate (SA) on the microtensile bond strengths (MTBSs) of different composites to bovine enamel after vital bleaching with hydrogen peroxide (HP) or carbamide peroxide (CP). Thirty bovine incisors were randomly divided into five groups and treated with no bleaching application (control), 35% HP alone, 35% HP + 10% SA for 10 minutes (HP + SA), 16% CP alone, or 16% CP + 10% SA for 10 minutes (CP + SA). Specimens were restored with Silorane adhesive and Filtek Silorane composite (designated as S / group) or with Clearfil SE bond and Filtek Supreme XT (designated as F / group). Composite build-up was created on the enamel. Sectioned specimens (n = 10 per group; 1 mm2; cross-sectional area) were created and stressed in a universal testing machine at 1 mm/min crosshead speed. The application of 10% SA immediately after bleaching with 16% CP or 35% HP increased the enamel MTBS, regardless of the adhesive / composite resin used. The resulting MTBS values were similar to those of the control groups. Use of 16% CP and 35% HP alone decreased the enamel MTBS, regardless of the adhesive / composite resin used, with F / CP + SA = F / HP + SA = F / CP = S / CP + SA = S / HP + SA = S / C > S / CP = S / HP = F / CP = F / HP (p < 0.05). We concluded that the application of SA for 10 minutes immediately after vital bleaching increases the enamel BS for dimethacrylate- and silorane-based composites.

Effect of Carbamide Peroxide Bleaching Gel on Composite Resin Flexural Strength and Microhardness

This study investigated the effect of 16% carbamide peroxide (Whiteness Perfect/FGM) on the Vickers microhardness and flexural strength of the restorative composites Filtek Z100 (hybrid), Filtek Z350 (nanofill), Brilliant (micro-hybrid) and Opallis (micro-hybrid). Disc-shaped (4x2 mm; n=5) and bar-shaped (12x2x1 mm; n=10) specimens of each restorative material were randomly divided into 2 groups: (G1) 16 weeks stored in distilled water; (G2) 16 weeks stored in distilled water, with 16% carbamide peroxide application during 6 h per day for the last 4 weeks. The mechanical properties were evaluated using a Vickers microhardness tester and a mechanical testing machine. Data were analyzed by two-way ANOVA and Tukey's (HSD) post-hoc test (α=0.05). Filtek Z100 presented the highest microhardness value, followed by Filtek Z350 and finally by Brilliant and Opallis (p=0.00). Filtek Z100 and Brilliant exhibited the highest flexural strength value, followed by Filtek Z350 and Opallis (p=0.00). Bleaching treatment decreased significantly microhardness of Brilliant and Opallis (p=0.00). The flexural strength of all studied materials was not affected by the home bleaching (p=0.28).

Este estudo investigou o efeito do peróxido de carbamida a 16% (Whiteness Perfect/FGM) na dureza Vickers e resistência à flexão dos compósitos restauradores Filtek Z100 (híbrida), Filtek Z350 (nanoparticulada), Brilliant (micro-híbrida) e Opallis (micro-híbrida). Espécimes em forma de disco (4x2 mm; n=5) e de barra (12x2x1 mm; n=10) de cada material restaurador foram distribuídos aleatoriamente em 2 grupos: (G1) 16 semanas em água destilada; (G2) armazenamento em água destilada durante 16 semanas, com aplicação do peróxido de carbamida a 16% por 6 h diárias nas últimas 4 semanas. As propriedades mecânicas foram avaliadas em microdurômetro Vickers e máquina de ensaios mecânicos. Os dados foram analisados por ANOVA a 2 critérios e teste de Tukey (α=0,05). Filtek Z100 apresentou o maior valor de dureza, seguido por Filtek Z350 e, finalmente, por Brilliant e Opallis (p=0,00). Filtek Z100 e Brilliant mostraram o maior valor de resistência à flexão, seguido por Filtek Z350 e Opallis (p=0,00). O clareamento diminuiu significantemente a dureza das resinas Brilliant e Opallis (p=0,00). A resistência à flexão dos materiais estudados não foi afetada pelo clareamento caseiro (p=0,28).

Color Stability, Surface Roughness and Flexural Strength of an Acrylic Resin Submitted to Simulated Overnight Immersion in Denture Cleansers

This study evaluated color stability, surface roughness and flexural strength of acrylic resin specimens after immersion in alkaline peroxide and alkaline hypochlorite, simulating a period of one and a half year of use of overnight immersion. Sixty disc-shaped (16X4 mm) and 80 rectangular specimens (65X10X3.3 mm) were prepared from heat-polymerized acrylic resin (Lucitone 550) and distributed into 4 groups (n=20): C1: without immersion, C2: 8 h immersion in distilled water; AP: 8 h immersion in alkaline peroxide effervescent tablet; SH: 8 h immersion in 0.5% NaOCl solution. Properties were evaluated at baseline and after the immersion. Color data were also calculated according the National Bureau of Standards (NBS). Results were analyzed statistically by ANOVA and Tukey's HSD test (α=0.05). AP (2.34 ± 0.41) caused color alteration significantly higher than C2 (0.39 ± 0.30) and SH (1.73 ± 0.52). The mean ΔE values were classified as indicial for C2 (0.36 ± 0.29) and noticeable for AP (2.12 ± 0.39) and SH (1.59 ± 0.48). SH (0.0195 ± 0.0150) caused significantly higher ΔRa (p=0.000) than the C2 (0.0005 ± 0.0115) and PA (0.0005 ± 0.0157) groups. There was no statistically significant difference (p=0.063) among the solutions for flexural strength (C1: 105.43 ± 14.93, C2: 100.30 ± 12.43, PA: 97.61 ± 11.09, SH: 95.23 ± 10.18). In conclusion, overnight immersion in denture cleansing solutions simulating a year and a half of use did not alter the flexural strength of acrylic resin but caused noticeable color alterations, higher for alkaline peroxide. The 0.5% NaOCl solution caused increase in surface roughness.

Resumo O estudo avaliou a alteração de cor, rugosidade de superfície e força de flexão de espécimes de resina acrílica após imersão em peróxido alcalino e hipoclorito alcalino, simulando um ano e meio de uso seguindo a imersão noturna. Sessenta espécimes circulares (16 X 4 mm) e oitenta retangulares (65 X 10 X 3,3 mm) de resina acrílica termopolimerizável (Lucitone 550) foram distribuídos em 4 grupos (n=20): C1: sem imersão, C2: 8 h de imersão em água destilada; PA: 8 h de imersão em pastilhas efervescentes de peróxido alcalino; HS: 8 h de imersão em hipoclorito de sódio a 0,5%. As propriedades foram avaliadas antes e após as imersões. Os dados de alteração de cor também foram calculados de acordo com o National Bureau of Standards (NBS). Os dados foram analisados estatisticamente pelo teste ANOVA e Tukey HSD (α=0,05). O PA (2,34 ± 0,41) causou alteração de cor significativamente maior que C2 (0,39 ± 0,30) e SH (1,73 ± 0,2). A média ΔE foi classificada como indicial para C2 (0,36 ± 0,29) e perceptível para PA (2,12 ± 0,39) e HS (1,59 ± 0,48). HS (0,0195 ± 0,0150) causou significantemente maior ΔRa (p=0) do que os demais (C2: 0,0005 ± 0,0115 e PA: 0,0005 ± 0,0157). Não houve diferença estatisticamente significante (p=0,063) entre as soluções para a resistência à flexão (C1: 105,43 ± 14,93; C2: 100,30 ± 12,43, PA: 97,61 ± 11,09, HS: 95,23 ± 10,18). A imersão noturna em soluções higienizadores de próteses simulando um ano e meio de uso não alterou a resistência à flexão da resina acrílica, porém causou alterações perceptíveis de cor, sendo maiores com o peróxido alcalino. O hipoclorito de sódio a 0,5% ...

Effect of dental bleaching after bracket bonding and debonding using three different adhesive systems

OBJECTIVE: To evaluate the influence of bonding and debonding of orthodontic brackets on dental in-home bleaching, taking into account three different adhesive systems. METHODS: Forty-four bovine incisors were divided into four groups according to the primer system used for orthodontic bracket bonding. Following the debonding of orthodontic brackets, the teeth were stored in staining solution for 96 hours. Then, teeth were whitened using 10% carbamide peroxide for two weeks at a 6-hour-a-day regime. Standardized digital photographs were taken at the following intervals: T0 (initial); T1 (after debonding); T2 (after pigmentation); T3, T4 and T5 representing 1, 7, and 14 days of bleaching. Repeatability and stability tests were carried out to check the method accuracy. Images were analyzed using Adobe Photoshop 7.0 software considering (L*a*b*)color coordinate values and a modified color difference total (Δ;E'). RESULTS: The results of this study (ANOVA and Tukey; p < 0.01) demonstrated that after 7 days of bleaching, experimental groups showed significantly less teeth whitening compared to the control group. However, there were no significant color differences between the groups after 14 days, according to values of lightness (L*). CONCLUSIONS: Regardless of the adhesive primer system applied, bonding and debonding of orthodontic brackets alters the outcome of tooth whitening in the first 7 days of bleaching, however it has no influence on the whitening of the dental structure after 14 days of in-home dental bleaching with 10% carbamide peroxide.

OBJETIVO: o objetivo desse estudo foi avaliar a influência da colagem e descolagem de braquetes ortodônticos no clareamento caseiro, considerando três diferentes sistemas adesivos. MÉTODOS: quarenta e quatro incisivos bovinos foram divididos em quatro grupos, de acordo com o sistema adesivo utilizado para colagem dos braquetes. Após a descolagem dos braquetes, os dentes foram pigmentados por 96 horas e depois clareados com peróxido de carbamida a 10% por 6 horas diárias, durante duas semanas. Foram realizadas fotografias digitais padronizadas nos tempos: T0 (inicial); T1 (após descolagem); T2 (após pigmentação); T3, T4 e T5 representando 1, 7 e 14 dias de clareamento. Testes de repetitividade e de estabilidade foram realizados para avaliar a acurácia do método. As imagens foram avaliadas pelo software Adobe Photoshop 7.0, considerando os parâmetros de cor (L*a*b*) e a diferença total de cor adaptada para esse estudo (Δ;E'). RESULTADOS: os resultados do presente estudo (ANOVA e Tukey; p < 0,01) demonstraram que, após uma semana de clareamento, os grupos experimentais apresentaram uma resposta mais lenta ao clareamento que o grupo controle. Contudo, após 14 dias, não houve diferença cromática significativa entre os grupos, observada pelos valores de luminosidade (L*). CONCLUSÕES: independentemente do sistema adesivo utilizado, a colagem e descolagem de braquetes ortodônticos altera os resultados de obtenção de cor com sete dias de avaliação. Contudo, após 14 dias não se observa nenhuma diferença de cor na estrutura dentária clareada pela técnica caseira.

Influence of fluoride-containing adhesives and bleaching agents on enamel bond strength

This study evaluated the influence of fluoride-containing carbamide peroxide (CP) bleaching agents and adhesive systems on bonded enamel interfaces that are part of the dynamic pH cycling and thermal cycling models. The buccal surfaces of 60 bovine incisors were restored with a composite resin and bonded with three- and two-step, etch-and-rinse, fluoride-containing adhesives, Optibond FL (FL) and Optibond Solo Plus (SP), respectively. Restored teeth were subjected to thermal cycling to age the interface. Both SP and FL adhesive-restored teeth were bleached (n = 10) with 10% CP (CP) and 10% CP + fluoride (CPF) or were left unbleached (control). Bleaching was performed for 14 days simultaneously with pH cycling, which comprised of 14 h of remineralization, 2 h of demineralization and 8 h of bleaching. The control groups (FL and SP) were stored in remineralizing solution during their bleaching periods and were also subjected to carious lesion formation. Parallelepiped-shaped samples were obtained from the bonded interface for microtensile bond strength (∝TBS) testing. The enamel ∝TBS of the FL and SP groups (control, not bleached) were higher (p < 0.05) than those of the bleached interfaces (FL > FL + CPF = FL + CP and SP > SP + CPF = SP + CP). The groups subjected to treatment with the fluoride-containing bleaching agents exhibited similar ∝TBS compared to regular bleaching agents. Bleaching agents, regardless of whether they contained fluoride, decreased enamel bond strength.

Ion release from a composite resin after exposure to different 10% carbamide peroxide bleaching agents

OBJECTIVE: This in vitro study evaluated the influence of two 10% carbamide peroxide bleaching agents - a commercial product (Opalescence PF; Ultradent Products, Inc.) and a bleaching agent prepared in a compounding pharmacy - on the chemical degradation of a light-activated composite resin by determining its release of ions before and after exposure to the agents. MATERIAL AND METHODS: Thirty composite resin (Filtek Z250; 3M/ESPE) samples were divided into three groups: group I (exposed to Opalescence PF commercial bleaching agent), group II (exposed to a compounded bleaching agent) and group III (control - Milli-Q water). After 14 days of exposure, with a protocol of 8 h of daily exposure to the bleaching agents and 16 h of immersion in Milli-Q water, the analysis of ion release was carried out using a HP 8453 spectrophotometer. The values were analyzed statistically by ANOVA, Tukey's test and the paired t-tests. The significance level was set at 5%. RESULTS: After 14 days of the experiment, statistically significant difference was found between group II and groups I and III, with greater ion release from the composite resin in group II. CONCLUSIONS: The compounded bleaching agent had a more aggressive effect on the composite resin after 14 days of exposure than the commercial product and the control (no bleaching).

Effectiveness of different carbamide peroxide concentrations used for tooth bleaching: an in vitro study

OBJECTIVES: This in vitro study evaluated the effectiveness of three carbamide peroxide concentrations used for tooth bleaching treatments. MATERIAL AND METHODS: Sixty bovine dental slabs (6x6x3 mm) were obtained, sequentially polished, submitted to artificial staining (baseline) and randomized into four groups (n=15), according to the bleaching agent concentration: distilled water (control), 10% (CP10), 16% (CP16) or 37% (CP37) carbamide peroxide. CP10 and CP16 were covered with 0.2 mL of the respective bleaching gels, which were applied on enamel surface for 4 h/day during two weeks. Samples of CP37 were covered with 0.2 mL of the bleaching gel for 20 min. The gel was light activated by two 40-s applications spaced by 10-min intervals. The gel was renewed and applied 3 times per clinical session. This cycle was repeated at 3 sessions with 5 days of interval between them. Tooth shade evaluations were done with a digital spectrophotometer at T0 (baseline), T1 (after 1-week of treatment) and T2 (1-week post-bleaching). Tooth shade means were statistically analyzed by Kruskal-Wallis and Friedman's tests and color parameters were analyzed by two-way ANOVA and Tukey's test (p<0.05). RESULTS: At T1 and T2 evaluations, tooth shade was significantly lighter than at baseline for all treatment groups, considering the color parameters ΔL*, Δa*, Δb*, ΔE* (p<0.001) or tooth shade means (p<0.001). CP37 group showed lower shade mean change than CP10 and CP16 at T1 (p<0.01), but this difference was not statistically significant at T2 (p>0.05). CONCLUSIONS: One week after the end of the treatment, all carbamide peroxide concentrations tested produced similar tooth color improvement.

Restauraciones directas con resina compuesta inmediatas al blanqueamiento dental: relato de un caso / Immediate resin composite restorations after dental bleaching: a case report

Objetivo. Relatar el uso de un gel antioxidante como paso intermedio para realizar restauraciones directas en resina compuesta inmediatas al blanqueamiento dental. Caso clínico. El tratamiento estético de los diente ántero-superiores e inferiores se inició con el blanqueamiento en el consultorio con peróxido de hidrógeno. Luego se aplicó sobre las superficies dentales con gel antioxidante de ascorbato de sodio al 10 por ciento durante 60 minutos para eliminar los residuos del gel blanqueador y se realizó el recontorno cosmético de los eis dientes antero-superiores con resinas compuestas directas, de este modo se evitó un tiempo de espera de aproximadamente 7 días después del blanqueamiento dental. Conclusiones. El uso de un gel de ascorbato de sodio al 10 por ciento permitió la realización de restauraciones directas en resina compuesta inmediatas al blanqueamiento dental, de forma segura.

Effects of different concentrations of carbamide peroxide and bleaching periods on the roughness of dental ceramics

The wide use of dental bleaching treatment has brought concern about the possible effects of hydrogen peroxide on dental tissue and restorative materials. The objective of this study was to evaluate in vitro the effect of nightguard bleaching on the surface roughness of dental ceramics after different periods of bleaching treatment. Fifteen specimens of 5 × 3 × 1 mm were created with three dental ceramics following the manufacturers' instructions: IPS Classic (Ivoclar-Vivadent); IPS d.Sign (Ivoclar-Vivadent); and VMK-95 (Vita). A profilometer was used to evaluate baseline surface roughness (Ra values) of all ceramics by five parallel measurements with five 0.25 mm cut off (Λc) at 0.1 mm/s. Afterwards, all specimens were submitted to 6-h daily bleaching treatments with 10 percent or 16 percent carbamide peroxide (Whiteness- FGM) for 21 days, while control groups from each ceramic system were stored in artificial saliva. The surface roughness of all groups was evaluated after 18 h, 42 h, 84 h, and 126 h of bleaching treatment. The surface roughness of each specimen (n = 5) was based on the mean value of five parallel measurements in each time and all data were submitted to two-way repeated measures ANOVA and Tukey's post-hoc test (α = 0.05). No significant differences in ceramic surface roughness were observed between untreated and bleached ceramic surfaces, regardless of bleaching intervals or bleaching treatments. This study provided evidence that at-home bleaching systems do not cause detrimental effects on surface roughness of dental ceramics.

Physical-chemical characteristics of whitening toothpaste and evaluation of its effects on enamel roughness

This in vitro study evaluated the physical-chemical characteristics of whitening toothpastes and their effect on bovine enamel after application of a bleaching agent (16 percent carbamide peroxide). Physical-chemical analysis was made considering mass loss by desiccation, ash content and pH of the toothpastes. Thirty bovine dental enamel fragments were prepared for roughness measurements. The samples were subjected to bleaching treatments and simulated brushing: G1. Sorriso Dentes Brancos (Conventional toothpaste), G2. Close-UP Whitening (Whitening toothpaste), and G3. Sensodyne Branqueador (Whitening toothpaste). The average roughness (Ra) was evaluated prior to the bleaching treatment and after brushing. The results revealed differences in the physical-chemical characteristics of the toothpastes (p < 0.0001). The final Ra had higher values (p < 0.05) following the procedures. The mean of the Ra did not show significant differences, considering toothpaste groups and bleaching treatment. Interaction (toothpaste and bleaching treatment) showed significant difference (p < 0.0001). The whitening toothpastes showed differences in their physical-chemical properties. All toothpastes promoted changes to the enamel surface, probably by the use of a bleaching agent.

Estudo in vivo do manchamento dental causado pela ingestão de café associada ao clareamento profissional / In vivo study of dental discoloration caused by coffee ingestion associated within-office dental bleaching

Objective: The present study aims to verify the effectiveness of in-office dental bleaching using 35% hydrogen peroxide in patients with or without a habit of consuming coffee at least three times per day at different time intervals (pre-bleaching or baseline;48 hours post-bleaching or start; and 90 days post-bleaching or recall). Methods and Material - Forty patients with superior and inferior vital teeth from canine to canine participated in this study. The optical measurements with SpectroShade Microspectrophotometer (MHT, Verona, Italy) determined the pre-bleaching status (baselinemeasurement), the status at 48 hours post-bleaching (start measurement), and thestatus at 90 days post-bleaching (recall measurement). The Delta E (ΔE) value was determined, and the difference between the pre- and post-bleaching luminosity was used as an indicator of the degree of chromogenic alteration. The patients were divided into four groups according to the presence or absence of a coffee ingestion habit and according to different post-bleaching time intervals. These data were analyzed by ANOVA and in case of significant differences the mean values were compared usingthe Tukey test (p < 0.05). Results and Conclusions - In conclusion, it was possible to confirm that professional dental bleaching is an effective technique that can be usedboth in patients who drink and do not drink coffee. However, the maintainability of this treatment was significantly reduced in the group of patients who habitually drink coffee within a period of only 90 days

Objetivos: O presente estudo visa verificar a efetividade do clareamento dental profissional utilizando o peróxido de hidrogênio a 35% em pacientes com e sem o hábito de ingestão de café por pelo menos três vezes ao dia em diferentes intervalosde tempo (pré-clareamento ou baseline; 48 horas pós-clareamento ou start; e 90 diaspós-clareamento ou recall). Material e Métodos - Quarenta pacientes com dentes naturais inferiores e superiores participaram deste estudo. As tomadas de cor com o espectrofotômetro SpectroShade (MHT, Verona, Itália) determinaram a condição pré clareamento(medição baseline), a condição em 48 horas pós-clareamento (medição start),e a condição após 90 dias (medição recall). O valor de Delta E (ΔE) foi determinado, e a diferença entre a luminosidade na condição pré e pós-clareamentos foram utilizadas como o indicador do grau de alteração cromatogênica. Os pacientes foram divididos em quatro grupos de acordo com a presença ou ausência de hábitos de ingestão de café e dos diferentes períodos pós-clareamento. Os dados foram analisados via ANOVA e, quando necessário, os valores médios foram comparados utilizando o teste de Tukeya 5% de significância (p < 0.05). Resultados e Conclusões - Como conclusão foi possível confirmar que clareamento dental profissional é uma técnica efetiva e que pode ser utilizada tanto em pacientes que ingerem como nos que não ingerem café. Contudo, a durabilidade deste tratamento clareador é significativamente reduzida no grupo de pacientes que habitualmente bebem café dentro de um período relativamente curto, ou seja, de apenas 90 dias

Effect of bleaching agent on dental ceramics roughness

The aim of this study was to assess the effect of bleaching agents (10% and 16% carbamide peroxide) on the roughness of two dental ceramics in vitro, and to analyze the surface by scanning electronic microscopy (SEM). Two bleaching agents (10% and 16% / Whiteness, FGM Gel) and two microparticle feldspathic ceramics (Vita VM7 and Vita VM13) were used. Forty disks of Vita VM7 and Vita VM13 ceramic were manufactured, measuring 4mm in diameter and 4mm high, in accordance with the manufacturers’ recommendations, and were divided into 4 groups (n=10): (1) VM7 + Whiteness 10%; (2) VM7 + Whiteness 16%; (3) VM13 + Whiteness 10%; (4) VM13 + Whiteness 16%. The bleaching agent was applied for 8 hours a day for 15 days and during the intervals the test specimens were stored in distilled water at 37°C. The roughness (Ra) of the test specimens was evaluated before and after exposure to the bleaching agents using a laser roughness meter and the topographic description was analyzed by SEM. The statistical analysis of roughness data showed significant differences in the VM7 groups, using paired t-test, p=0.05 (VM7 + Whiteness 10%: p=0.002; VM7 + Whiteness 16%: p=0.001) and two-sample t-test (VM7 p=0,047), and no significant difference was found among VM13 groups. The qualitative SEM analysis showed different degrees of surface changes. The results suggest that the roughness of the tested ceramic surfaces increased after exposure to the bleaching agents.

O objetivo do estudo foi avaliar o efeito de agente clareador (10% e 16% de peroxido de carbamida) na rugosidade de duas ceramicas dentais in vitro e analisar a superficie atraves da microscopia eletronica de varredura (SEM). Foram utilizados dois agentes clareadores (10% e 16% / Whiteness, FGM Gel) e duas ceramicas feldspaticas microparticuladas (Vita VM7 e Vita VM13). Foram confeccionados quarenta discos de ceramica Vita VM7 e Vita VM13, com 4mm de diametro e 4mm de altura, de acordo com as recomendacoes do fabricante, sendo divididos em 4 grupos (n=10): G1- VM7 + Whiteness 10%, G2- VM7 + Whiteness 16%, G3- VM13 + Whiteness 10% e G4- VM13 + Whiteness 16%. O agente clareador foi aplicado por 8 horas durante 15 dias e durante os intervalos os corpos de prova (cp) ficavam armazenados em agua destilada a 37°C. A rugosidade (Ra) dos cp foi avaliada antes e apos a exposicao aos agentes clareadores utilizando o rugosimetro a laser Perthomether S8P, e a descricao topografica foi analisada no MEV. A analise estatistica na rugosidade mostrou diferenca significante entre os grupos da VM7, usando o teste pareado, p=0.05 (VM7 + Whiteness 10%: p=0.002; VM7 + Whiteness 16%: p=0.001) e nao foi encontrado diferenca estatistica para os grupos da VM13. A descricao qualitativa no SEM evidenciou alteracao nas superficies em diferentes graus. Os resultados sugeriram que as superficies das ceramicas testadas aumentaram a rugosidade apos a exposicao ao agente clareador.

Acción de agentes químicos en la eliminación de Candida albicans sobre prótesis dentales / The action of chemical agents on the removal of Candida albicans on dental prosthesis

Se realizó un estudio in vitro, para evaluar la efectividad de cuatro agentes químicos en la eliminación de Cándida albicans sobre prótesis dentales. 10 cuadros de resina acrílica (25 x 25 x 3 mm) fueron sumergidos en un medio contaminado con C. albicans; luego de lavados, 2 muestras por cada grupo se introdujeron en soluciones desinfectantes (grupo 1: control; grupo 2: hipoclorito de sodio al 2 por ciento; grupo 3: ácido acético al 5 por ciento; grupo 4: peróxidos alcalinos; grupo 5: gluconato de clorhexidina al 0.12 por ciento). Posteriormente, se pipeteó 1 cc de solución de cada uno de los desinfectantes a diferentes tiempos de desinfección (5, 10, 15, 20 min y 8 horas) colocándolos en tubos de ensayo con caldo de Sabouraud e incubados a 37ºC por 48 horas. No se observó crecimiento fúngico sobre ninguna muestra a partir de los 20 minutos. Se concluyó que todos los agentes químicos usados en la desinfección de prótesis fueron efectivos para la eliminación de C. albicans.

The effectiveness of four chemical agents to eliminate Candida albicans on dentures was evaluated in this "in vitro" study. 10 Acrylic resin squares (25 x 25 x 3 mm) were immersed in a C albicans contaminated solution. 2 samples per group were rinse and immersed in their disinfecting solutions, as follows: Group 1 control physiologic solution; group 2, sodium hypochlorite 2%; group 3, acetic acid 5%; group 4, alkaline peroxides; chlorhexidine gluconate 0.12%. 1 ml of disinfecting solutions were taken at 5, 10, 15, 20 and 480 min and placed on Sabouraud solution at 37 °C for 48 h. There was no fungi development at 20 or more minutes for any of the experimental groups. It was concluded that all the disinfecting agents used in this research are suitable to be used for dentures against C albicans.

Evaluación del blanqueamiento dentario de piezas teñidas con tetraciclina utilizando peróxido de carbamida al 10 por ciento con carbopol a largo plazo / A long-term evaluation of bleaching tetracycline-stained teeth using 10 per cent carbamide peroxide with carbopol

Las tinciones de los dientes por tetraciclina corresponden a una patología de tinción dentaria intrínseca adquirida, difícil de tratar por métodos no conservadores. El objeto de este estudio fue la aplicación de un blanqueamiento extendido con peróxido de carbamida al 10 por ciento con carbopol (Opalescence) con una cubeta individual de blanqueamiento nocturno por 4 horas diarias por 16 semanas, para verificar diferencias y la eficacia de este tratamiento en controles a las 8 y 16 semanas. Se seleccionaron 4 pacientes con sus dientes anterosuperiores teñidos con el antibiótico (24 dientes en total) que cumplieran requisitos específicos de salud y que aceptaran realizarse un tratamiento extendido sólo del maxilar superior. Se realizaron controles clínicos y fotográficos a las 2, 4, 8, 12 y 16 semanas. Para la muestra en cuestión, no se encontraron diferencias significativas en la cantidad de grises (o valor) entre los controles 0 y 8 semanas (mayor blanqueamiento dentario). Asimismo, se encontró un mayor grado de blanqueamiento entre 0 y 16 semanas y entre 8 y 16 semanas de control. El 100 por ciento de los pacientes presentó sensibilidad en los primeros controles no se evidenciaron cambios en el sabor e irritación gingival. Se concluye que el blanqueamiento extendido de dientes teñidos por tetraciclina logra un éxito para la muestra revisada, pero se requieren mayores estudios acerca de la regresión de las tinciones en el tiempo