Effect of Toothbrushing with Different Dentifrices on the Surface of an Infiltrant Resin Used to Inactivate White Spot Lesions

Objective: To verify whether an infiltrant resin used to inactivate white spot lesions (WSL) on enamel can resist the abrasive challenges promoted by tooth brushing with different dentifrices. Material and Methods: WSL was induced on bovine enamel samples (pH cycling) and then treated with an infiltrant resin (ICON). Afterward, half of the sample was protected. The other half underwent an abrasive challenge using an electric toothbrush with soft bristles., using dentifrices with different abrasiveness (n=10): Group 1: Colgate Maximum Cavity Protection; Group 2: Sensodyne Repair & Protect; Group 3: Colgate Sensitive Pro-Relief; Group 4: Colgate 2 in 1 Watermelon Flavor; e Group 5: Colgate Luminous White Advanced. The wear profile after brushing was evaluated by confocal laser scanning microscopy (µm), and the enamel/resin interface was observed in scanning electron microscopy (SEM). Profilometry data were analyzed using one-way ANOVA followed by Tukey\u27s test (α=5%). Results: Brushing produced more significant wear on group 5 (3.96±0.26) when compared to groups 1 (3.45±0.21), 2(3.22±0,4) and 4(3.11±0.34). Data from Group 3 (3.82±0.6) was similar to G5 but higher than G1, G2, and G4. SEM analysis showed that the adhesive interface remained intact in all groups after the abrasive challenge. Conclusion: Dentifrices with a higher relative dentin abrasiveness produced more significant wear of the infiltrant, but the composite/enamel interface was not altered after the abrasive challenges

Er,Cr:YSGG and 980nm diode lasers influence dentin surface volume after cariogenic challenge: in vitro study

Abstract This study aimed to evaluate the influence of the Er,Cr:YSGG irradiation and 980-nm diode lasers on the surface roughness (SR) and volume loss (VL) of dentin subjected to cariogenic challenge. Subsequently, 130 specimens of bovine dentin were divided into the following 13 groups: NT: no treatment; FG: fluoride gel; FV: fluoride varnish; Di: 980-nm diode; Di + FG; Di + FV; FG + D; FV + Di; Er: Er,Cr:YSGG; Er + FG; Er + FV; FG + Er and FV + Er. Er,Cr:YSGG laser parameters were as follows: 0.25 W; 5.0 Hz; 4.46 J/cm2 without water and 55% air. Furthermore, the 980-nm diode laser parameters were 2.0 W; 2.0 Hz; 21.41 J/cm2. The samples from each group were subjected to pH cycling. A confocal laser scanning microscope was used to evaluate SR and VL. Difference between the volume of the reference and treated areas + DES/RE was used to determine SR and VL. The mean values of the different groups were subjected to analysis of variance and Tukey’s post-hoc test. The VL values were analyzed using the Kruskal–Wallis and Dunn post-hoc test (p 0.05). Moreover, VL in the FV + Di and FV + Er groups showed a statistically significant difference compared with areas submitted to different types of treatment and cariogenic challenge (p > 0.05). Er,Cr:YSGG and 980-nm diode lasers associated with fluoride varnishes decreased dentin VL in bovine teeth submitted to cariogenic challenge

The combined use of Er,Cr:YSGG laser and fluoride to prevent root dentin demineralization

The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria. Objective: To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz) irradiation associated with 2% neutral sodium fluoride (NaF) to prevent root dentin demineralization. Material and Methods: One hundred human root dentin samples were divided into 10 groups (G) and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2) with water cooling (WC=5.4 mL/min); G4: laser (4.64 J/cm2) without WC; G5: laser (8.92 J/cm2) with WC; G6: laser (8.92 J/cm2) without WC; G7: laser (4.64 J/cm2) with WC and NaF; G8: laser (4.64 J/cm2) without WC and NaF; G9: laser (8.92 J/cm2) with WC and NaF; G10: laser (8.92 J/cm2) without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN) test was done at different depths (30, 60, 90 and 120 μm) from the outer dentin surface. Data were analyzed by one-way ANOVA and Fisher’s test (α=5%). Results: The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (p<0.05). Conclusions: The use of Er,Cr:YSGG laser irradiation at 4.64 J/ cm2 and 8.92 J/cm2 without water cooling and associated with 2% NaF can increase the acid resistance of human root dentin

Influence of beverages and brushing on the physical properties of a composite resin

Objetivo: Este estudo avaliou a influência de bebidas e escovação na estabilidade de cor, rugosidade superficial e microdureza em profundidade de uma resina composta. Materiais e Método: 120 discos (10mm de diâmetro X 2mm de espessura) de resina composta (Filtek- Z250) foram preparados e polidos após 24 horas. A cor inicial e a rugosidade superficial inicial foram mensuradas e os espécimes foram divididos aleatoriamente em quatro grupos (vinho tinto, refrigerante, aguardente, ou saliva artificial controle) e três subgrupos (sem escovação; escovação com Colgate, ou escovação com Close Up Whitening). Os espécimes foram imersos na sua respectiva solução, 5x ao dia, por 5 minutos, durante 30 dias, sendo dois subgrupos escovados ao final de cada dia (120 movimentos/dia). A cor foi mensurada no 15º e no 30º dia de imersão; a rugosidade superficial final foi medida no 30º dia. Após o período de imersão, os espécimes foram armazenados em saliva artificial por 7 dias, quando a superfície dos mesmos foi polida e imediatamente realizou-se uma mensuração de cor. A alteração de cor foi mensurada com um espectrocolorímetro e analisada pelos valores de &Delta;E, &Delta;L, &Delta;a, e &Delta;b. Os valores de rugosidade (Ra-&mu;m) foram medidos com um rugosímetro. Com relação à microdureza, os espécimes primeiramente foram incluídos em resina de poliéster e seccionados no sentido transversal. Após o polimento destas superfícies, foram realizadas mensurações nas profundidades de 30&mu;m, 60&mu;m, 90&mu;m, 120&mu;m e 250&mu;m, empregando os parâmetros 25gf/40s de microdureza Knoop. Os dados foram submetidos à ANOVA e teste de Fisher\'s (&alpha;=5%). Resultados: Os valores de alteração de cor foram estatisticamente diferentes após a imersão nas bebidas; o vinho tinto promoveu a maior alteração, seguido pelo refrigerante e aguardente, que foram similares entre si e diferentes da saliva artificial. Nenhuma diferença foi observada com ou sem escovação, independentemente do dentifrício utilizado. Ao 30º dia, os espécimes apresentaram uma mudança de cor mais intensa do que ao 15º dia, após o repolimento, a cor dos espécimes foi similar à cor do 15º dia. As bebidas e a escovação influenciaram negativamente na rugosidade da superfície. Em relação à microdureza, não houve diferença significativa entre os grupos, independentemente da profundidade analisada. Conclusões: A mudança de cor da resina composta foi influenciada apenas pelas bebidas; a escovação não afetou a propriedade analisada. O repolimento não foi suficiente para promover o retorno da cor dos espécimes aos valores iniciais. A rugosidade superficial foi influenciada negativamente tanto pelas bebidas quanto pela escovação. Para a microdureza, a resina composta apresentou resultados similares independentemente das bebidas utilizadas e da presença ou ausência de escovação nos espécimes avaliados.Objective: This study evaluated the influence of beverages and brushing on the color change, surface roughness and microhardness in depth of a composite resin. Methods: 120 composite resin disks (10mm-øX2mm-thickness; Filtek-Z250) were prepared and polished after 24h. Initials color and surface roughness were measured and specimens were randomly assigned into four groups (red wine, soft drink, sugar cane spirit, or artificial saliva control) and three subgroups (without brushing; brushing with Colgate, or brushing with Close Up Xtra Whitening). Specimens were immersed in the beverage 5x/day, for 5 minutes, over 30 days, being two subgroups brushed at the end of every day (120 moving/day). Color was measured at the 15th and 30th days of immersion; final surface roughness was measured at the 30th day. After the immersion period, specimens were stored in artificial saliva for 7 days, when their surfaces were repolished and immediately assessed by color. Color change was measured with a spectrocolorimeter and analyzed by &Delta;E, &Delta;L, &Delta;a, and &Delta;b values. The values of roughness (Ra - &mu;m) were measured with a rugosimeter. As regard microhardness, the specimens were firstly included in polyester resin and sectioned in the transverse direction. After polishing these surfaces, measurements were realized at depths of 30&mu;m, 60&mu;m, 90&mu;m, 120&mu;m and 250&mu;m, employing the parameters 25gf/40s of microhardness Knoop. Data were submitted to ANOVA and Fisher\'s tests (&alpha;=5%). Results: Color change values were statistically different after immersion in the beverages; red wine promoted the highest alteration, followed by soft drink and sugar cane spirit, which presented similar results among them and different from saliva. No difference was observed with or without brushing independently of the toothpaste used. At 30th day, specimens exhibited a color change higher than 15th day; after repolishing, the color of the specimens was similar to 15th day. Beverages and brushing negatively influenced the surface roughness. In relation to microhardness, there was no significant difference among groups, regardless of the depth examined. Conclusions: Color change of the composite resin was influenced only by the beverages and brushing did not affect the analyzed property. The repolishing was not sufficient to promote the return of the specimens color to their initial values. The surface roughness was negatively influenced both by the beverage as brushing. For microhardness, the composite resin showed similar results regardless of the beverages used and the presence or absence of brushing in the specimens tested

Influence of laser irradiation on root caries prevention

Objetivo: Este estudo avaliou a influência do uso de diferentes lasers, associados ou não à aplicação de fluoreto de sódio, na prevenção da cárie radicular. Materiais e Método: Para este estudo, 128 espécimes de dentina radicular humana (4,25mm X 4,25mm e 3,00mm de espessura) foram divididos aleatoriamente em 8 grupos: (G1=nenhum tratamento, G2=aplicação de flúor gel, G3=irradiação com o laser Er:YAG, G4=aplicação de flúor gel + irradiação com o laser Er:YAG, G5=irradiação com o laser Nd:YAG, G6=aplicação de flúor gel + irradiação com o laser Nd:YAG, G7=irradiação com o laser CO2, G8=aplicação de flúor gel + irradiação com o laser CO2. Para os grupos que receberam irradiação laser , metade do espécime foi irradiada (&asymp;9,00mm2) e a outra metade não (região controle). Nos grupos que receberam flúor gel, este foi aplicado antes da irradiação laser por 4 minutos. Após o tratamento dos espécimes, estes foram submetidos a desafios cariogênicos (ciclos de pH) em soluções desmineralizante (pH=5,0) e remineralizante (pH=7,0), por 6 horas e 18 horas, respectivamente, completando um período experimental de 14 dias. A avaliação dos tratamentos realizados nos grupos experimentais foi feita através dos seguintes testes: 1-) mensuração da porcentagem de desmineralização através de microscopia óptica MO; 2-) avaliação da morfologia da superfície irradiada através de microscopia eletrônica de varredura MEV; 3-) análise da microdureza das paredes de fundo da dentina radicular desmineralizada em diferentes profundidades através do teste de microdureza longitudinal; 4-) quantificação da porcentagem dos elementos cálcio, fósforo e flúor através de micro análise por energia dispersiva de raios X EDS. Os dados foram submetidos a diferentes testes estatísticos, dependendo da propriedade analisada. Resultados: Os lasers Nd:YAG e CO2 foram mais eficazes na diminuição da porcentagem de desmineralização do que o laser Er:YAG. A menor porcentagem de desmineralização foi observada no G7. Na microscopia eletrônica da varredura, o laser Er:YAG proporcionou mudanças mais satisfatórias que os demais, na medida em que observou-se uma dentina mais lisa e homogênea, sem trincas ou áreas de carbonização. O laser Er:YAG também foi superior no aumento da resistência ácida da dentina, quando avaliada pelo teste de microdureza. O G3 obteve os maiores valores médios de microdureza Knoop. Em relação à análise de EDS, houve uma tendência de incorporação do flúor nas áreas irradiadas, principalmente após irradiação com os lasers Er:YAG e CO2. Conclusões: Todos os lasers testados apresentaram resultados promissores na prevenção da cárie radicular e, para as propriedades analisadas, não houve sinergismo resultante da aplicação de flúor gel previamente à irradiação laser.Objective: This study evaluated the influence of different lasers, associated or not with sodium fluoride application, in the prevention of root caries. Materials and Methods: For this study, 128 specimens of human root dentin (4.25mm X 4.25mm and 3.00mm thick) were randomly divided into 8 groups: (G1=no treatment, G2=application of fluoride gel, G3= Er:YAG laser irradiation, G4=application of fluoride gel + Er:YAG laser irradiation, G5= Nd:YAG laser irradiation, G6=application of fluoride gel + Nd:YAG laser irradiation, G7= CO2 laser irradiation, G8= application of fluoride gel + CO2 laser irradiation. For the groups that received laser irradiation, half of the specimen was irradiated (&asymp;9.00mm2) and the other half was not (control region). In the groups that received fluoride gel, this was applied before laser irradiation for 4 minutes. After treatment of samples, these were submitted to a cariogenic challenge (pH cycles) in demineralizing (pH=5.0) and remineralizing (pH=7,0) solutions for 6 hours and 18 hours, respectively, completing an experimental period of 14 days. The evaluation of the proposed treatments in the experimental groups was performed using the following tests: 1-) measurement of the percentage of demineralization by light microscopy MO; 2-) assessment of the morphology of the irradiated surface by scanning electron microscopy MEV; 3-) microhardness analysis of the bottom walls of demineralized root dentin at different depths through the test of longitudinal microhardness; 4-) quantification of the percentage of the elements calcium, phosphorus and fluoride through micro analysis by energy dispersive X-ray - EDS. Data were submitted to different statistical tests, depending on the analyzed property. Results: Nd:YAG and CO2 lasers were more effective in decreasing the percentage of demineralization than the Er:YAG laser. The lowest percentage of demineralization was observed in the G7. In the scanning electron microscopy, the Er:YAG laser provided more satisfactory changes than the others, considering that there was a more smooth and homogeneous dentine, without cracks or carbonization areas. The Er:YAG laser was also greater in increasing the acid resistance of the dentin, when evaluated by microhardness test. The G3 obtained the highest average values of Knoop microhardness. Regarding the analysis of EDS, there was a tendency of incorporating fluoride in the irradiated areas, especially after irradiation with Er:YAG and CO2 lasers. Conclusions: All the tested lasers showed promising results in the prevention of root caries and for the analyzed properties, no synergism resulting from the application of fluoride gel prior to laser irradiation was found

Surface roughness and color change of a composite: Influence of beverages and brushing

This study evaluated the influence of beverages and brushing on the surface roughness(SR) and color change(Delta E) of a composite resin. For this, 120-disks(10 mmx2 mm) of composite resin(Filtek-Z250) were prepared and polished. Initials SR(Ra-mu m) and color(CIELab-system) were measured with rugosimeter and spectrophotometer; specimens were divided into four groups(red wine, soft drink, sugar cane spirit, or artificial saliva=control) and three subgroups(without brushing; brushed with Colgate or with Close-Up). Specimens were immersed in the beverage 5x/day, for 5', over 30 day, being two subgroups brushed(120 strokes/day). Color was measured at 15th day, 30th day and after repolishment; SR at 30th day. Delta E-values were statistically different after immersion in the beverages(p&lt;0.05). Red wine promoted the highest alteration, followed by soft drink=sugar cane spirit and finally saliva. At 30th day, specimens exhibited Delta E higher than 15th day; after repolishing, Delta E was similar to 15th day. Beverages and brushing negatively influenced the SR. Therefore, Delta E and SR can be influenced by beverages and brushing.CAPESCoordenacao de Aperfeicoamento de Pessoal de Nivel SuperiorCAPES-Coordenacao de Aperfeicoamento de Pessoal de Nivel Superio

The combined use of Er,Cr:YSGG laser and fluoride to prevent root dentin demineralization

The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria. Objective: To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz) irradiation associated with 2% neutral sodium fluoride (NaF) to prevent root dentin demineralization. Material and Methods: One hundred human root dentin samples were divided into 10 groups (G) and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2) with water cooling (WC=5.4 mL/min); G4: laser (4.64 J/cm2) without WC; G5: laser (8.92 J/cm2) with WC; G6: laser (8.92 J/cm2) without WC; G7: laser (4.64 J/cm2) with WC and NaF; G8: laser (4.64 J/cm2) without WC and NaF; G9: laser (8.92 J/cm2) with WC and NaF; G10: laser (8.92 J/cm2) without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN) test was done at different depths (30, 60, 90 and 120 μm) from the outer dentin surface. Data were analyzed by one-way ANOVA and Fisher’s test (α=5%). Results: The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (

Influence of preventive remineralizing techniques on surface roughness and volume loss of dentin submitted to erosive and/or abrasive challenges

BACKGROUND: The objective this study was to evaluate the influence of preventive remineralizing techniques on surface roughness and volume loss of dentin submitted to erosive and/or abrasive challenges. MATERIAL AND METHODS: One hundred and eighty specimens of bovine root dentin were made; half of each was isolated (without treatment - WT) and half was subjected to the following remineralizing techniques: fluoride varnish (FV); Regenerate Boosting Serum® (RBS); Er,Cr:YSGG laser (L); fluoride varnish+laser (FV+L); Regenerate Boosting Serum®+laser (RBS+L). The specimens were submitted to erosive, abrasive and erosive followed by abrasive challenge. Erosion was carried out for 5 minutes, twice a day for 10 days. Abrasion was performed with an electric toothbrush and slurry solution for 60 seconds. The evaluation was performed by confocal laser scanning microscopy. Analysis of variance and Tukey tests were used for surface roughness; volume loss comparison was performed using the Kruskal-Wallis test and Dunn's post-hoc (p0.05). Regarding volume loss, the untreated group submitted to erosive/abrasive challenges showed greater percentage of volume loss compared to the other groups (p<0.05). CONCLUSIONS: It is concluded that preventive remineralizing techniques are effective in maintaining dentin volume after erosive/abrasive challenges. Key words:YSGG lasers, Dentin, Erosion, Tooth Abrasion