Development and effect of orodispersible film incorporated with Biosilicate for remineralization of dental enamel subjected to cariogenic and erosive challenge.

OBJECTIVES: The objective of this in vitro study was to assess the efficiency of incorporating Biosilicate particles (30 and 50 mg) into an experimental orodispersible film and its efficacy in the remineralization process of bovine dental enamel under cariogenic and erosive challenges. METHODS: Ninety-nine intact incisors, devoid of cracks or fractures, yielding 198 samples (6 × 6 × 2 mm) via vestibular sectioning using a low-speed diamond disc under water cooling. After flattening the enamel surface with 600, 1200, and 2000 grit sandpaper, the samples were divided into two groups based on the challenges they underwent: cariogenic (0.1 M lactic acid at pH 5.0) or erosive (0.05 M citric acid solution at pH 2.3). Samples from each challenge were further categorized into 11 groups (n = 9) according to the duration of cariogenic (3, 7, and 14 days) or erosive (3, 7, and 10 days) challenge, along with positive control groups (fragments untreated with challenges and treated with different Biosilicate concentrations) and negative controls (fragments treated with artificial saliva for the same periods established for cariogenic and erosive challenges). Treatments with orodispersible films containing Biosilicate (30 and 50 mg) were administered for 2 min per day for 15 days. RESULTS: The highest remineralizing potential was observed in samples treated with Biosilicate after 14 days of cariogenic challenge, irrespective of the concentration tested. For samples subjected to erosive challenge, erosion time did not affect Biosilicate's remineralizing potential. CONCLUSION: Biosilicate shows promise in terms of remineralizing potential in enamel subjected to cariogenic challenge due to its ability to form hydroxycarbonapatite in mineralized tissues.

Incorporation of bioactive glass-ceramic into coconut oil for remineralization of incipient carious lesions.

This study evaluated the efficacy of incorporating different concentrations of bioactive glass-ceramic (Biosilicate) into coconut oil on the remineralizing potential and surface roughness of white spot lesions. Fragments (6 x 6 x 2mm) of bovine teeth were sectioned and initial microhardness (KHN) and surface roughness (Ra) readings were obtained. The samples were submitted to cariogenic challenge to form white spot lesions and were separated into six groups (n=13): 1) Artificial Saliva (AS); 2) Coconut Oil (CO); 3) CO+2% Biosilicate (CO+2%Bio); 4) CO+5% Biosilicate (CO+5%Bio); 5) 2% Biosilicate Suspension (2% Bio) and 6) 5% Biosilicate Suspension (5% Bio). The treatments for 1 cycle/day were: immersion into the treatments for 5 minutes, rinsing in distilled water, and storage in artificial saliva at 37ºC. After 14 days, KHN and Ra readings were taken. The surface roughness alteration ((Ra) was analyzed (Kruskal-Wallis, Dunn's post-test, p<0.05). CO+2%Bio had higher (p = 0.0013) (Ra followed by CO+5%Bio (p = 0.0244) than AS. The relative KHN and remineralization potential were analyzed (ANOVA, Tukey, p<0.05), and 5% Bio treatment presented a higher relative microhardness than all other groups (p>0.05). The remineralizing potential of all the treatments was similar (p > .05). When Biosilicate was added, the pH of the suspensions increased and the alkaline pH remained during the analysis. Biosilicate suspension is more efficient than the incorporation of particles into coconut oil at white spot lesion treatment. In addition to the benefits that coconut oil and Biosilicate present separately, their association can enhance the remineralizing potential of Biosilicate.

Effect of artificial aging on mechanical and physical properties of CAD-CAM PMMA resins for occlusal splints.

PURPOSE: This study aimed to assess and compare the color stability, flexural strength (FS), and surface roughness of occlusal splints fabricated from heat-cured acrylic resin, milled polymethyl methacrylate (PMMA)-based resin, and 3D-printed (PMMA) based-resin. MATERIALS AND METHODS: Samples of each type of resin were obtained, and baseline measurements of color and surface roughness were recorded. The specimens were divided into three groups (n = 10) and subjected to distinct aging protocols: thermomechanical cycling (TMC), simulated brushing (SB), and control (without aging). Final assessments of color and surface roughness and three-point bending test (ODM100; Odeme) were conducted, and data were statistically analyzed (2-way ANOVA, Tukey, P <.05). RESULTS: Across all resin types, the most significant increase in surface roughness (Ra) was observed after TMC (P < .05), with the 3D-printed resin exhibiting the lowest Ra (P < .05). After brushing, milled resin displayed the highest Ra (P < .05) and greater color alteration (ΔE00) compared to 3D-printed resin. The most substantial ΔE00 was recorded after brushing for all resins, except for heat-cured resin subjected to TMC. Regardless of aging, milled resin exhibited the highest FS (P < .05), except when compared to 3D-printed resin subjected to TMC. Heat-cured resin exposed to TMC demonstrated the lowest FS, different (P < .05) from the control. Under control conditions, milled resin exhibited the highest FS, different (P < .05) from the brushed group. 3D-printed resin subjected to TMC displayed the highest FS (P < .05). CONCLUSION: Among the tested resins, 3D-printed resin demonstrated superior longevity, characterized by minimal surface roughness and color alterations. Aging had a negligible impact on its mechanical properties.

Antimicrobial effect of phytosphingosine in acrylic resin.

This study evaluated color stability (CS), anti-adherence effect (AAE), and cell viability of microorganisms on acrylic resin (AR) surface, treated associated or not with sodium percarbonate (SP). AR specimens were prepared, and color analysis was performed before and after the treatments and the CS was calculated. For analysis of AAE, the samples were sterilized by radiation in a microwave oven. Then samples were randomly distributed: phosphate-buffered saline (PBS - control), 0.5% sodium hypochlorite (SH), phytosphingosine (PHS), and phytosphingosine + SP (PHS+Na2CO3). The specimens remained in contact with solutions for 30 minutes and were later contaminated by Candida albicans. Aliquots were seeded in Petri dishes with Sabouraud Dextrose agar and incubated at 37°C for 24 hours. After the incubation, the number of colonies was counted. The cell viability of adhered microorganisms on the AR was evaluated and 20 fields were observed under an epifluorescence microscope, and the percentage of adhered viable cells was calculated. Data were compared (One-way ANOVA, Tukey, p<.05). As for CS, PHS+ Na2CO3 (0.4±0.1) resulted in less change than PBS (0.9±0.2), similar to the other groups (SH [1.0±0.3)]; PHS [0.9±0.2)]). There was no difference for all tested solutions regarding the ability to avoid microorganism adherence (p>0.05), but PHS (11.2±4.1) resulted in a smaller area of adhered viable cells, statistically different from SH (18.2±7.6) and PBS (26.4±10.8). It was concluded that PHS resulted in lower adhered viable cells and when associated with Na2CO3, also shows a lower effect on the CS of AR.

Antimicrobial effect of phytosphingosine in acrylic resin

Abstract This study evaluated color stability (CS), anti-adherence effect (AAE), and cell viability of microorganisms on acrylic resin (AR) surface, treated associated or not with sodium percarbonate (SP). AR specimens were prepared, and color analysis was performed before and after the treatments and the CS was calculated. For analysis of AAE, the samples were sterilized by radiation in a microwave oven. Then samples were randomly distributed: phosphate-buffered saline (PBS - control), 0.5% sodium hypochlorite (SH), phytosphingosine (PHS), and phytosphingosine + SP (PHS+Na2CO3). The specimens remained in contact with solutions for 30 minutes and were later contaminated by Candida albicans. Aliquots were seeded in Petri dishes with Sabouraud Dextrose agar and incubated at 37°C for 24 hours. After the incubation, the number of colonies was counted. The cell viability of adhered microorganisms on the AR was evaluated and 20 fields were observed under an epifluorescence microscope, and the percentage of adhered viable cells was calculated. Data were compared (One-way ANOVA, Tukey, p<.05). As for CS, PHS+ Na2CO3 (0.4±0.1) resulted in less change than PBS (0.9±0.2), similar to the other groups (SH [1.0±0.3)]; PHS [0.9±0.2)]). There was no difference for all tested solutions regarding the ability to avoid microorganism adherence (p>0.05), but PHS (11.2±4.1) resulted in a smaller area of adhered viable cells, statistically different from SH (18.2±7.6) and PBS (26.4±10.8). It was concluded that PHS resulted in lower adhered viable cells and when associated with Na2CO3, also shows a lower effect on the CS of AR.

Resumo Este estudo avaliou estabilidade de cor (EC), efeito antiaderente (EAA) e viabilidade celular de microrganismos em superfície de resina acrílica (RA), tratada com solução de fitoesfingosina, associada ou não ao percarbonato de sódio (PS). Espécimes RA foram preparados e análise de cor foi realizada antes e após os tratamentos e EC foi calculada. Para análise de EAA, as amostras foram esterilizadas por radiação em forno de micro-ondas. Então foram distribuídas aleatoriamente: solução salina tamponada com fosfato (PBS - controle), hipoclorito de sódio 0,5% (SH), fitoesfingosina (PHS) e fitoesfingosina + SP (PHS+Na2CO3). Os espécimes permaneceram em contato com as soluções por 30 minutos e posteriormente foram contaminados por Candida albicans. Alíquotas foram semeadas em placas de Petri com ágar Sabouraud Dextrose e incubadas a 37°C por 24 horas. Após a incubação, o número de colônias foi contado. A viabilidade celular dos microorganismos aderidos na RA foi avaliada e 20 campos foram observados em microscópio de epifluorescência, e a porcentagem de células viáveis aderidas foi calculada. Os dados foram comparados (One-way ANOVA, Tukey, p<0,05). Quanto a EC, o PHS+ Na2CO3 [0,4 (0,1)] resultou em menor alteração que o PBS [0,9 (0,2)], semelhante aos demais grupos (SH [1,0 (0,3)]; PHS [0,9 (0,2)]). Não houve diferença para todas as soluções testadas quanto à capacidade de evitar a aderência de microorganismos (p>0,05), mas o PHS [11,2 (4,1)] resultou em uma área menor de células viáveis aderidas, estatisticamente diferente do SH [18,2 (7,6)] e PBS [26,4 (10,8)]. Concluiu-se que o PHS resultou em menor número de células viáveis aderidas e, quando associado ao Na2CO3, também apresenta menor efeito sobre o EC da RA.

The effect of Phytosphingosine and bioactive glass-ceramics in preventing dental enamel erosion.

This study evaluated the effect of phytosphingosine (PHS) and bioactive glass-ceramic (Biosilicate) on dental enamel in terms of color alteration (ΔE), microhardness, and surface roughness when submitted to erosive challenge (EC). Sixty specimens of bovine teeth (6×6×2mm) were obtained. Initial color (Easyshade, VITA), KHN (HMV-2, Shimadzu), and Ra (SJ-201P, Mitutoyo) measurements were performed. Specimens were separated into groups according to treatments: PHS, 10% Biosilicate, PHS+10% Biosilicate, and artificial saliva (control) and submitted to EC with Coca-Cola for 2 min. This cycle was repeated 4 times daily/15 days. Between cycles, specimens remained in artificial saliva (2 h/37°C). After daily cycles, they were also stored in artificial saliva at 37ºC. Final color, microhardness, and surface roughness measurements were done. Color and KHN data were analyzed by one-way ANOVA, Tukey's test; and Ra, by 2-way ANOVA, repeated measures, and Tukey's test (p<.05). The highest ΔE occurred in Saliva+EC (p<.05). Groups treated with PHS presented lower color change than Saliva+EC (p<.05). All the groups presented mean values above the 50:50% perceptibility (50:50%PT) and acceptability (50:50%AT) thresholds, except for control that showed mean value above 50:50%PT but below 50:50%AT. Biosilicate+EC showed higher relative microhardness than Saliva+EC (p<.05), but was similar to PHS+EC and PHS+Biosilicate+EC. Final enamel surface roughness increased for all the groups (p<.05), except for the control. The Biosilicate may prevent enamel mineral loss induced by erosion better than saliva. The PHS associated or not to Biosilicate demonstrated better color stability than saliva.

The effect of Phytosphingosine and bioactive glass-ceramics in preventing dental enamel erosion

Abstract This study evaluated the effect of phytosphingosine (PHS) and bioactive glass-ceramic (Biosilicate) on dental enamel in terms of color alteration (ΔE), microhardness, and surface roughness when submitted to erosive challenge (EC). Sixty specimens of bovine teeth (6×6×2mm) were obtained. Initial color (Easyshade, VITA), KHN (HMV-2, Shimadzu), and Ra (SJ-201P, Mitutoyo) measurements were performed. Specimens were separated into groups according to treatments: PHS, 10% Biosilicate, PHS+10% Biosilicate, and artificial saliva (control) and submitted to EC with Coca-Cola for 2 min. This cycle was repeated 4 times daily/15 days. Between cycles, specimens remained in artificial saliva (2 h/37°C). After daily cycles, they were also stored in artificial saliva at 37ºC. Final color, microhardness, and surface roughness measurements were done. Color and KHN data were analyzed by one-way ANOVA, Tukey's test; and Ra, by 2-way ANOVA, repeated measures, and Tukey's test (p<.05). The highest ΔE occurred in Saliva+EC (p<.05). Groups treated with PHS presented lower color change than Saliva+EC (p<.05). All the groups presented mean values above the 50:50% perceptibility (50:50%PT) and acceptability (50:50%AT) thresholds, except for control that showed mean value above 50:50%PT but below 50:50%AT. Biosilicate+EC showed higher relative microhardness than Saliva+EC (p<.05), but was similar to PHS+EC and PHS+Biosilicate+EC. Final enamel surface roughness increased for all the groups (p<.05), except for the control. The Biosilicate may prevent enamel mineral loss induced by erosion better than saliva. The PHS associated or not to Biosilicate demonstrated better color stability than saliva.

Resumo Este estudo avaliou o efeito da Fitoesfingosina (PHS) e da vitrocerâmica bioativa (Biosilicato) sobre o esmalte dental em termos de alteração de cor (ΔE), microdureza (KHN) e rugosidade superficial, quando submetido a desafio erosivo (DE). Sessenta espécimes de dentes bovinos (6×6×2mm) foram obtidos. Foram realizadas leituras de cor inicial (Easyshade, VITA), microdureza (HMV-2, Shimadzu) e rugosidade superfícial (SJ-201P, Mitutoyo). Os espécimes foram separados em grupos de acordo com os tratamentos: PHS, Biosilicato a 10%, PHS+Biosilicato a 10%, e saliva artificial (controle). Em seguida, foram submetidos a DE com Coca-Cola por 2 min. Esse ciclo foi repetido 4 vezes/dia por 15 dias. Entre os ciclos, as amostras foram mantidas em saliva artificial (2 h/37°C). Após os ciclos diários, os espécimes também foram armazenados em saliva artificial a 37ºC. Foram realizadas leituras finais de cor, microdureza e rugosidade superficial. Os dados de cor e microdureza foram analisados ​​por ANOVA de uma via, teste de Tukey; e dados de rugosidade superficial, por ANOVA de duas vias, teste de Tukey (p<.05). A maior ΔE ocorreu em Saliva+DE (p<.05). Grupos tratados com PHS apresentaram menor alteração de cor do que Saliva+DE (p<.05). Biosilicate+DE demonstrou valores intermediários, similar (p>.05) aos outros grupos, exceto Saliva+DE. Todos os grupos presentaram média acima dos limites 50:50% de perceptibilidade (50:50%LP) e aceitabilidade (50:50%LA) exceto o controle que demonstrou média acima do 50:50%LA mas abaixo do 50:50%LP. Biosilicate+DE mostrou maior microdureza realativa do que Saliva+DE (p<.05), mas similar a PHS+DE e PHS+Biosilicato+DE. A rugosidade de superfície do esmalte aumentou para todos os grupos, exceto para o controle que presentou a menor alteração (p<.05). O Biosilicato apode prevenir perda mineral do esmalte indizido pela erosão melhor que a saliva. O PHS associado ou não ao Biosilicato demonstrou melhor estabilidade de cor que a saliva.

The effect of phytosphingosine associated with tooth brushing on color change, surface roughness, and microhardness of dental enamel - an in vitro and in situ study.

OBJECTIVE: This study evaluated the in vitro and in situ effects of phytosphingosine (PHS) associated with tooth brushing on color stability, surface roughness, and microhardness of dental enamel. METHODS: Sixty-four specimens of bovine teeth (6 × 6 × 2 mm) were separated into 8 groups (n = 8): S + TB: PHS (spray) + tooth brushing; TB + S: tooth brushing + PHS (spray); I + TB: PHS (immersion) + tooth brushing; TB + I: tooth brushing + PHS (immersion); TB: tooth brushing; S: PHS spray; I: immersion in PHS solution, and Saliva: immersion in saliva. Tooth brushing simulation (Mavtec, Brazil) was performed (356 rpm on 3.8 cm area by the toothbrush - Soft Tek) for 1, 7, 15, and 30 days. PHS remained in contact with specimens for 15 min. The specimens were evaluated before and after tooth brushing for color alteration (Easy Shade, VITA), and surface roughness (Model SJ-201P Mitutoyo), and Knoop microhardness (HMV-2, Shimadzu Corporation). For the in situ analyses, 8 participants were recruited and received an intraoral device with 6 fragments of bovine enamel (6 × 6 × 2 mm). The properties evaluated were the same as those of the in vitro study. Participants were randomized following best results of in vitro tested protocols, for 15 days: TB, TB + S, I + TB. Data obtained by in vitro (two-way ANOVA, Tukey, p < .05) and in situ (one-way ANOVA, Tukey, p < .05) studies were analyzed. RESULTS: The in vitro study showed that greater color change was found after 30 days. The greatest differences in surface roughness occurred between the initial value and after 1 day. Regarding microhardness, the highest values occurred after 15 and 30 days, which showed similar results. The in situ study showed greater color changes for the TB and I + TB, and greater surface roughness changes for TB as well as a similar increase in microhardness for the PHS protocols, which were higher than TB. CONCLUSIONS: Phytosphingosine leads to an increase in performance regarding color stability, surface roughness, and microhardness when applied. In general, the application of PHS after brushing showed a positive impact on its performance. CLINICAL RELEVANCE: Phytosphingosine proved to be interesting for compound prevention formulations in the dentistry field.

Incorporation of bioactive glass-ceramic into coconut oil for remineralization of incipient carious lesions

Abstract This study evaluated the efficacy of incorporating different concentrations of bioactive glass-ceramic (Biosilicate) into coconut oil on the remineralizing potential and surface roughness of white spot lesions. Fragments (6 x 6 x 2mm) of bovine teeth were sectioned and initial microhardness (KHN) and surface roughness (Ra) readings were obtained. The samples were submitted to cariogenic challenge to form white spot lesions and were separated into six groups (n=13): 1) Artificial Saliva (AS); 2) Coconut Oil (CO); 3) CO+2% Biosilicate (CO+2%Bio); 4) CO+5% Biosilicate (CO+5%Bio); 5) 2% Biosilicate Suspension (2% Bio) and 6) 5% Biosilicate Suspension (5% Bio). The treatments for 1 cycle/day were: immersion into the treatments for 5 minutes, rinsing in distilled water, and storage in artificial saliva at 37ºC. After 14 days, KHN and Ra readings were taken. The surface roughness alteration ((Ra) was analyzed (Kruskal-Wallis, Dunn's post-test, p<0.05). CO+2%Bio had higher (p = 0.0013) (Ra followed by CO+5%Bio (p = 0.0244) than AS. The relative KHN and remineralization potential were analyzed (ANOVA, Tukey, p<0.05), and 5% Bio treatment presented a higher relative microhardness than all other groups (p>0.05). The remineralizing potential of all the treatments was similar (p > .05). When Biosilicate was added, the pH of the suspensions increased and the alkaline pH remained during the analysis. Biosilicate suspension is more efficient than the incorporation of particles into coconut oil at white spot lesion treatment. In addition to the benefits that coconut oil and Biosilicate present separately, their association can enhance the remineralizing potential of Biosilicate.

Resumo Este estudo avaliou a eficácia da incorporação de diferentes concentrações de vitrocerâmica bioativa (biosilicato) ao óleo de coco no potencial remineralizante e na rugosidade superficial de lesões de manchas brancas. Fragmentos (6 x 6 x 2mm) de dentes bovinos foram seccionados e as leituras iniciais de microdureza (KHN) e rugosidade superficial (Ra) foram obtidas. As amostras foram submetidas ao desafio cariogênico para formação de lesões de manchas brancas e foram separadas em seis grupos (n=13): 1) Saliva Artificial (AS); 2) Óleo de Coco (CO); 3) CO+2% Biosilicato (CO+2%Bio); 4) CO+5% Biosilicato (CO+5%Bio); 5) Suspensão de Biosilicato 2% (2% Bio) e 6) Suspensão de Biosilicato 5% (5% Bio). Os tratamentos de 1 ciclo/dia foram: imersão nos tratamentos por 5 minutos, enxágue em água destilada e armazenamento em saliva artificial a 37ºC. Após 14 dias, foram feitas as leituras de KHN e Ra. A alteração da rugosidade superficial ((Ra) foi analisada (Kruskal-Wallis, pós-teste de Dunn, p<0,05). CO+2%Bio apresentou maior (p = 0,0013) (Ra seguido de CO+5%Bio (p = 0,0244) do que AS. O KHN relativo e o potencial de remineralização foram analisados (ANOVA, Tukey, p<0,05), e o tratamento 5% Bio apresentou uma microdureza relativa maior do que todos os outros grupos (p>0,05). A suspensão de biosilicato é mais eficiente que a incorporação de partículas ao óleo de coco no tratamento de lesões de mancha branca. Além dos benefícios que o óleo de coco e o Biosilicato apresentam separadamente, sua associação pode amplificar o potencial remineralizante do Biosilicato.

Whitening efficacy of popular natural products on dental enamel

Abstract The objective of this study was to evaluate the effect of natural bleaching products on the color, whiteness, and superficial properties of dental enamel. Seventy fragments of bovine teeth were obtained (6mm x 6mm x 2mm). Initial surface roughness (Surfcorder SE1700, Kosakalab), microhardness (HMV-2, Shimadzu), color (EasyShade, VITA), and surface gloss (Micro-Gloss 45º BYK, Gardner) readings were done. Samples were separated into five groups (n=14) according to the treatments used: CT-conventional toothpaste (negative control); CH-charcoal; TU-turmeric; BP-banana peel, and CP16%-16% carbamide peroxide gel (positive control, 4 h/day for 14 days), and then brushed for 560 cycles (T1) and 1200 cycles (T2), equivalent to 14 and 30 days of brushing. New measurements were performed after T1 and T2. The whiteness index for dentistry change (∆WID) and Weight loss (Wl) were calculated. CP16% demonstrated the highest (p<.05) color change (ΔE00) and ∆WID (2-way ANOVA, Bonferroni, p<.05). Surface gloss alterations were lower for TU, CP16%, and BP. CT and CH increased surface roughness (p<.05). CP16% decreased enamel microhardness. CH presented medium abrasiveness, and CT and TU, low abrasiveness. The popular bleaching products were not efficient for tooth whitening. Furthermore, brushing with charcoal increased the enamel surface roughness, and CP16% decreased enamel microhardness over time

Resumo O objetivo deste estudo foi avaliar o efeito de produtos clareadores naturais na cor, efeito clareador e propriedades superficiais do esmalte dentário. Setenta fragmentos de dente bovino foram obtidos (6mm x 6mm x 2mm). Foram realizadas leituras iniciais de rugosidade de superfície (Surfcorder SE1700, Kosakalab), microdureza (HMV-2, Shimadzu), cor (EasyShade, VITA) e brilho (Micro-Gloss 45º BYK, Gardner). As amostras foram separadas em cinco grupos (n=14), de acordo com os tratamentos utilizados: DC - dentifrício convencional (controle negativo); CA - carvão ativado; CM - cúrcuma; CB - casca de banana e PC16% - gel de peróxido de carbamida a 16% (controle positivo, 4h/dia por 14 dias), foram então escovadas por 560 ciclos (T1) e 1200 ciclos (T2), equivalente a 14 e 30 dias de escovação. Novas leituras foram realizadas após T1 e T2. A alteração do whiteness index for dentistry (∆WID) e perda de massa (Pm) foram calculadas. PC16% demonstrou a maior (p<0,05) alteração de cor (ΔE00) e ∆WID (2-way ANOVA, Bonferroni, p<0,05). A alteração de brilho foi menor para CM, PC16% e CB. DC e CA aumentaram a rugosidade de superfície (p<0,05). PC16% diminuiu a microdureza do esmalte. CA apresentou abrasividade média, e DC e CM, baixa abrasividade. Os produtos clareadores populares não foram eficientes para clareamento dental. Ademais, a escovação com carvão ativado aumentou a rugosidade de superfície do esmalte dentário, e com maior tempo PC16% diminuiu a microdureza do esmalte.

Whitening efficacy of popular natural products on dental enamel.

The objective of this study was to evaluate the effect of natural bleaching products on the color, whiteness, and superficial properties of dental enamel. Seventy fragments of bovine teeth were obtained (6mm x 6mm x 2mm). Initial surface roughness (Surfcorder SE1700, Kosakalab), microhardness (HMV-2, Shimadzu), color (EasyShade, VITA), and surface gloss (Micro-Gloss 45º BYK, Gardner) readings were done. Samples were separated into five groups (n=14) according to the treatments used: CT-conventional toothpaste (negative control); CH-charcoal; TU-turmeric; BP-banana peel, and CP16%-16% carbamide peroxide gel (positive control, 4 h/day for 14 days), and then brushed for 560 cycles (T1) and 1200 cycles (T2), equivalent to 14 and 30 days of brushing. New measurements were performed after T1 and T2. The whiteness index for dentistry change (∆WID) and Weight loss (Wl) were calculated. CP16% demonstrated the highest (p<.05) color change (ΔE00) and ∆WID (2-way ANOVA, Bonferroni, p<.05). Surface gloss alterations were lower for TU, CP16%, and BP. CT and CH increased surface roughness (p<.05). CP16% decreased enamel microhardness. CH presented medium abrasiveness, and CT and TU, low abrasiveness. The popular bleaching products were not efficient for tooth whitening. Furthermore, brushing with charcoal increased the enamel surface roughness, and CP16% decreased enamel microhardness over time.

Color stability and microhardness alteration of irradiated dental enamel treated with a high fluoride concentration toothpaste.

OBJECTIVES: Radiotherapy (RT) is a kind of head and neck cancer (HNC) treatment, which is associated to the habit of smoking and can develop collateral effects in the oral cavity, such as the increase of caries prevalence. This study evaluated the color alteration, the microhardness, and the remineralizing potential of high fluoride concentration toothpastes on irradiated teeth. MATERIALS AND METHODS: Forty bovine teeth were used (6 × 6 × 2 mm) and after color (EasyShade, VITA) and microhardness initial readings were separated into two groups: exposed to cigarette smoke and non-exposed. All samples were submitted to RT (30 Gy) and to cariogenic challenge. New color and microhardness readings were done. After RT (60 Gy), the samples were submitted to simulated toothbrushing (73,000 cycles = 5 years of brushing) with two different toothpastes: conventional (1450 ppm) and high fluoride concentration (5000 ppm). Final color and microhardness readings were done after brushing. Data were analyzed with 2-way ANOVA with repeated measures and Tukey's test (p < .05). RESULTS: There was no color difference after RT, nor after brushing (p > .05). However, after brushing, microhardness values increased for the samples treated with high fluoride concentration toothpaste (p < .05). CONCLUSION: Radiotherapy did not influence the teeth color, and the high fluoride concentration toothpaste presented remineralizing potential; therefore, it could be used on the caries prevention related to HNC radiation. CLINICAL RELEVANCE: Considering its remineralizing potential, toothpastes with high fluoride concentration could be a proper alternative for caries prevention in patients undergoing radiotherapy.

Remineralization of caries-affected dentin and color stability of teeth restored after treatment with silver diamine fluoride and bioactive glass-ceramic.

OBJECTIVES: The aim of this study was to evaluate the microhardness of caries-affected dentin and color stability of teeth restored after treatments with silver diamine fluoride (SDF) associated to potassium iodide (KI) and Biosilicate. MATERIAL AND METHODS: Different samples from bovine teeth were obtained. For color readings, 80 cavities (6 mm × 6 mm × 2 mm) were prepared, and for microhardness, teeth were flattened into dentine to obtain 40 samples. All samples were submitted to cariogenic challenge and separated in 4 groups, according to the treatment used: 12% SDF + KI; 38% SDF; Biosilicate and control (no treatment). Cavities were restored with resin-modified glass-ionomer cement (RMGIC, Vitremer, 3 M ESPE) or composite resin (CR, Z350, 3 M ESPE). After restoration, the samples were submitted to thermo-mechanical cycling (TMC) for 1,200,000 cycles. Color readings (EasyShade, Vita) were performed after restorations, after TMC, and 30 days after TMC. Knoop microhardness was evaluated on the planned samples before and after cariogenic challenge, after treatments, and after 30 days. Scanning electron microscopy (SEM) evaluated the dentine surface after treatments. Data were analyzed (ANOVA, Bonferroni, p < .05). RESULTS: The results showed a higher color alteration for RMGIC than CR. The time of analysis was significant (p < .05) for the 12% SDF + KI and control group. There was no difference (p < .05) in microhardness between groups. However, there was evidence of dentin remineralization after treatments. CONCLUSIONS: It was concluded that the samples treated with Biosilicate resulted in a color alteration similar to control. The treatments presented dentin remineralizing potential for microhardness, below the demineralization level, caused by the cariogenic challenge. CLINICAL RELEVANCE: Considering the remineralizing potential presented by Biosilicate, this agent is a promising alternative that overcomes the SDF adverse effects such as tooth staining.

Effect of phytosphingosine on staining resistance and microhardness of tooth enamel.

OBJECTIVE: To evaluate the protective effect of phytosphingosine (PHS) against staining on dental enamel. MATERIALS AND METHODS: Ninety-six specimens of bovine teeth (6 mm × 6 mm × 2 mm) were cut, and initial color (Easyshade, VITA), microhardness (HMV-2, Shimadzu) and fluorescence (Matlabs software, Matworks) measurements were performed. Specimens were separated into four groups according to the treatments: Distilled water (control); Human saliva (HS); PHS; PHS + HS. Specimens (n = 6) were submitted to staining procedures: Distilled water (immersion for 30 days-control); Coffee (15 minutes, twice a day/for 15 days); Black tea (as described for Coffee) and cigarette smoke (20 cigarettes/sample). Final measurements were performed, and data were analyzed (Color-CIEDE2000, fluorescence-2-way ANOVA, Tukey, and microhardness-Kruskal-Wallis Dunn, P < .05). RESULTS: Coffee caused the highest color change (ΔE00 ), followed by black tea, regardless of the treatment employed. Distilled water and cigarette smoke produced similar color changes (P > .05) for the groups control (water = 1.0 + - 0.5/ cigarette = 2.3 0.3) and PHS (water = 0.8 0.4/ cigarette = 2.3 0.4). PHS + HS demonstrated intermediate means than PHS and HS when stained with coffee and tea. After treatments, the least fluorescence alterations occurred for the groups treated with distilled water and cigarette, regardless of the treatment, with no difference (P > .05) between them. There was a significant difference (P < .05) on microhardness between all the groups, as PHS + HS > PHS > HS > Distilled water. CONCLUSIONS: It was concluded that PHS treatment did not protect the staining of the enamel by coffee and tea, but increased the microhardness, both in the presence and absence of a salivary pellicle. PRACTICAL IMPLICATIONS: Phytoshingosine is a novel agent and considered a promising component for anti-biofilm and anti-erosion properties by the formation of a diffusion barrier on the dental enamel. In line, PHS might be considered for anti-staining purposes.