In-vitro evaluation of the anti-cariogenic effect of a hybrid coating associated with encapsulated sodium fluoride and stannous chloride in nanoclays on enamel

Objective: The aim of this study is to test, in vitro, the anti-cariogenic effect of experimental hybrid coatings, with nano clays of halloysite or bentonite, loaded with sodium fluoride or with a combination of sodium fluoride and stannous chloride, respectively. Methodology: The varnish Fluor Protector (1,000 ppm of F-) was used as positive control and no treatment was the negative control. Enamel specimens (5 mm × 5 mm) were obtained from bovine teeth. The specimens (n=10) had their surfaces divided into two halves (5 mm × 2.5 mm each), in which one half received one of the treatments (Hybrid; Hybrid + NaF; Hybrid + NaF + SnCl2; Hybrid + NaF Loaded; Hybrid + NaF + SnCl2 Loaded). The specimens were submitted to a cariogenic challenge using a biofilm model (S. mutans UA159, for 5 days). Enamel surfaces both under and adjacent to the treated area were analyzed for mineral loss and lesion depth, by transverse microradiography. The pH of the medium was measured twice a day, and the fluoride release was analyzed. Additional specimens were submitted to confocal analysis. Results: Data were statistically analyzed by two-way ANOVA followed by Tukey test (α=0.05). None of hybrid groups were able to reduce the lesion depth; the Hybrid + NaF group, however, was able to reduce mineral loss differing from the negative control (p=0.008). The groups showed no significant difference in the pH measurement and fluoride release. Confocal analysis confirmed that for all groups the biofilm growth was similar. Conclusion: None of the hybrid groups reduced lesion depth, but the Hybrid + NaF group was able to promote protection against mineral loss

Protection of calcium silicate/sodium phosphate/fluoride toothpaste with serum on enamel and dentin erosive wear

Objective: To evaluate the effect of a toothpaste containing calcium silicate/sodium phosphate/fluoride associated or not to the boost serum (BS) against erosive tooth wear (ETW) on enamel and dentin. Methodology: Bovine enamel and dentin specimens were subjected to an erosion-abrasion cycling model (1% citric acid - pH 3.6 -2 min / artificial saliva – 60 min, 4×/day, 5 days). Toothbrushing was performed for 15 s (2 min exposed to slurry), 2×/day, with the toothpastes (n=10): control without fluoride (Weleda), Arg/Ca/MFP (Colgate Pro-Relief), Si/PO4/MFP (Regenerate-Unilever), and Si/PO4/MFP/BS (Si/PO4/MFP with dual BS – Advanced Enamel Serum-Unilever). The effect of treatments on the eroded tissues was assessed by surface microhardness in the first day, and surface loss (SL) resulting from ETW was evaluated by profilometry (μm) after three and five days. Additional dentin specimens (n=5/group) were subjected to 20,000 brushing cycles to verify the abrasivity of the toothpastes. Data were subjected to ANOVA and correlation tests (5%). Results: For enamel, no difference in microhardness was observed among the treated groups, and similar SL was obtained after 5 days. For dentin, Si/PO4/MFP/BS resulted in higher microhardness values, but none of the groups presented significantly lower SL than the control. There was no significant correlation between SL and abrasiveness. Conclusion: The calcium silicate/sodium phosphate toothpaste and serum increased microhardness of eroded dentin, but they did not significantly reduce enamel and dentin loss compared to the non-fluoride control toothpaste. The abrasiveness of the toothpastes could not predict their effect on ETW

Effect of erosive and erosive/abrasive challenges on the dental hard tissues adjacent to restorations performed with materials containing fluoride or calcium

Esse estudo avaliou in vitro o efeito dos desafios erosivo ou erosivo/abrasivo sobre materiais restauradores contendo fluoreto ou cálcio e sobre as estruturas dentárias adjacentes às restaurações realizadas com esses materiais. Fragmentos de esmalte e de dentina bovinos (4 mm × 4 mm × 2 mm), foram incluídos em resina acrílica e planificados. Uma cavidade padrão com dimensões 1,2 mm × 4 mm × 1,5 mm foi preparada nos espécimes, e restaurada de acordo com o material a ser testado: 1. Z350 - resina composta (Filtek Z350, 3M ESPE); 2. VB - compósito experimental contendo apenas vidros de bário; 3. DCPD30% - compósito experimental contendo 10% de vidros de bário e 30% partículas de fosfato di-cálcio di-hidratado (DCPD) funcionalizadas com dimetacrilato de dietilenoglicol (DEGDMA); 4. DCPD60% - compósito experimental contendo 60% partículas de DCPD funcionalizadas com DEGDMA; 5. Beautifil - GIOMER (Beautifil II, Shofu Dental Corporation); 6. Fuji IX - cimento de ionômero de vidro convencional de alta viscosidade (Fuji IX, GC Corporation); 7. Fuji II LC - cimento de ionômero de vidro modificado por resina (Fuji II LC, GC Corporation). Na sequência, os espécimes foram polidos e submetidos a dois tipos de tratamentos: erosão somente (n=10) ou erosão mais abrasão por escovação (n=10). A erosão foi realizada pela imersão dos espécimes em ácido cítrico a 0,3% (pH~2,6) por 5 min, seguido de 60 min de imersão em saliva artificial. Esse procedimento foi repetido 4×/dia, por 5 dias. A escovação foi realizada com uma suspensão de dentifrício padrão (Colgate Total 12 Mint Clean; 1450 ppm F-, como NaF) por 15 s (2 min de exposição total a suspensão de dentifrício), 2×/dia, 30 min após o primeiro e o quarto desafios erosivos. Ao final da ciclagem, a perda superficial (em ?m) do esmalte, da dentina e dos materiais restauradores foi determinada com um perfilômetro ótico. Para cada modelo (erosão e erosão-abrasão), os dados de perda superficial de esmalte, dentina e restauração foram analisados de maneira independente. Os dados foram analisados pelos testes de Kruskal-Wallis e Tukey. O nível de significância utilizado foi de 5%. No modelo de erosão, para esmalte, ambos cimentos ionoméricos apresentaram menor perda superficial do que o compósito Z350, apesar de Fuji II LC não ter se diferenciado significativamente dos grupos Beautifil e DCPD30%. Os outros grupos não foram diferentes de Z350 nem entre si. Para dentina, nenhum dos grupos foi diferente de Z350, com exceção de DCPD60%, o qual apresentou a maior perda superficial. Ambos cimentos ionoméricos apresentaram menor perda do que DCPD30%, Beautifil e DCPD60%. Em relação à restauração, os materiais Z350, Beautifil, VB, DCPD30% apresentaram perda superficial mínima, sem diferenças entre eles. Os cimentos ionoméricos apresentaram os maiores valores de perda, não se diferenciando de DCPD60%. No modelo erosão-abrasão, para esmalte, a menor perda superficial foi observada em Fuji II LC, sem diferença da Beautifil. Os outros grupos não se diferenciaram entre si nem da Beautifil. Para dentina, os grupos DCPD60%, Beautifil, Fuji II LC, Z350 e Fuji IX não se diferenciaram e, apresentaram menor perda superficial do que VB. Os cinco grupos citados também não foram diferentes de DCPD30%, com exceção de Fuji IX. Em relação à restauração, a maior perda foi observada para Fuji IX, sem diferenças de Fuji II LC e Beautifil. DCPD30%, Z350, VB e DCPD60% apresentaram valores mínimos de perda superficial, sem diferenças entre si. Concluiu-se que o cimento ionomérico Fuji II LC foi único capaz de proteger o esmalte adjacente à restauração contra desafios erosivos e erosivos/abrasivos, apesar de ter sido um dos materiais mais susceptíveis ao desgaste por ambos desafios. Para dentina, nenhum material exibiu efeito protetor.This in vitro study evaluated the effect of erosive or erosive/abrasive challenges on restorative materials containing fluoride and calcium, and on the dental hard tissues adjacent to restorations performed with these materials. Enamel and dentin specimens (4 mm × 4 mm × 2 mm), obtained from bovine incisors, were embedded in acrylic resin, flattened and polished. In the specimens, a standard cavity of 1,2 mm × 4 mm × 1,5 mm was prepared and restored with the following materials: 1. Z350 - Composite resin without actives, Filtek Z350 (3MESPE); 2. VB - experimental composite containing barium glass only; 3. DCPD30% - experimental composite containing 10% of barium glass and 30% of DCPD particles functionalized with DEGDMA; 4. DCPD60% - experimental composite containing 60% of DCPD particles functionalized with DEGDMA; 5. Beautifil - GIOMER (Beautifil II, Shofu Dental Corporation); 6. Fuji IX - high viscosity glass ionomer (Fuji IX, GC Corporation); 7. Fuji II LC - resin-modified glass ionomer (Fuji II LC, GC Corporation). The specimens were polished again and then submitted to one of the two treatments: erosion only (n=10) or erosion plus toothbrushing abrasion (n=10). Erosion was performed by immersing the specimens in 0.3% citric acid solution (p~2.6), for 5 min, followed by 60 min exposure to artificial saliva. This procedure was repeated 4 times a day, for 5 days. Toothbrushing was performed with a slurry of a standard dentifrice (Colgate Total 12 Mint Clean; 1450 ppm F, as NaF), for 15 s (2 min total exposure time to the slurry), 2 times a day, 30 min after the first and last erosive challenges. At the end of cycling, enamel, dentin and restorative material surface loss (in ?m) were determined by optical profilometry. Data were analyzed by the Kruskal-Wallis and Tukey tests. The level of significance was 5%. In the erosion model, for enamel, both ionomeric cements presented lower surface loss than the Z350, although Fuji II LC did not differ significantly from Beautifil and DCPD30% groups. The other groups were no different from Z350 and from each other. For dentin, none of the groups were different from Z350, except for DCPD60%, which presented the highest surface loss. Both ionomeric cements presented lower loss than DCPD30%, Beautifil and DCPD60%. Regarding the restoration, the materials Z350, Beautifil, VB, DCPD30% showed minimal surface loss, with no differences between them. The ionomeric cements had the highest loss values, not differing from DCPD60%. In the erosion-abrasion model, for enamel, the lowest loss was observed for Fuji II LC, with no difference to Beautifil. The other groups showed no difference among them and from Beautifil. For dentin, the groups DCPD60%, Beautifil, Fuji II LC, Z350 and Fuji IX were no significant different and presented lower loss than VB. These five groups were also no different from DCPD30%, except Fuji IX. Regarding the restoration, the highest loss was observed for Fuji IX, with no difference from Fuji II LC and Beautifil. DCPD30%, Z350, VB and DCPD60% presented minimum values of surface loss, without differences between them. It was concluded that Fuji II LC ionomeric cement was the only material able to protect the enamel adjacent to the restoration against erosive and erosive/abrasive challenges, although it was one of the materials that was most susceptible to be wear off by both challenges. For dentin, no material exhibited a significant protective effect

Evaluation of an experimental bioglass on surface loss and tubular occlusion of dentin, and its association with photobiomodulation therapy in human pulp cell differentiation

A hipersensibilidade dentinária (HD) é uma condição dolorosa que afeta negativamente a qualidade de vida dos indivíduos. Ainda não existe, contudo, um tratamento considerado padrão-ouro para mitigar a dor aguda gerada por esta condição. Sendo assim, os objetivos deste estudo foram: 1. Verificar os efeitos de um biovidro experimental na permeabilidade dentinária (PD, por meio da condutância hidráulica) e na perda de superfície dentinária (PS, determinada com perfilometria óptica); 2. Analisar os efeitos da associação do biovidro com a terapia de fotobiomodulação na diferenciação funcional de células pulpares, indicando potencial para formação de dentina terciária e, assim, oclusão biológica dos túbulos dentinários. Para a primeira fase do estudo, 48 discos de dentina coronária (1 mm de espessura, n=12) foram usados para PD e 48 fragmentos de dentina radicular (3 mm × 3 mm, n=12) para PS, que foram avaliadas em 3 momentos: pós-EDTA (5 min em solução de EDTA 17%); pós-tratamento (C: água destilada; BV: pasta de biovidro experimental; NP: pasta de profilaxia Nupro; CXT: verniz Clinpro XT); e pós-ciclagem (solução de ácido cítrico 0,3% por 5 min, seguido de 60 min imersão em saliva humana, 4 ×/dia, 5 dias. A escovação foi realizada 2 ×/dia por 15 s, com 1,5 N e um dentifrício fluoretado padrão pasta - exposição total de 2 min). Imagens de microscopia eletrônica de varredura (MEV, n=3) foram obtidas pós-tratamento e pós-ciclagem para análise qualitativa. Imagens adicionais do pó de biovidro e análise por espectroscopia por energia dispersiva (EDS) foram realizadas para caracterizar a partícula. Na segunda fase, os mesmos tratamentos foram testados, associados ou não à terapia de fotobiomodulação [PBM - laser de diodo de fosfeto de índio-gálio-alumínio, InGAlP, (660 nm, 0,028 cm2, 20 mW, 0,71 W/cm2, 5 J/cm2) 7 s, modo contínuo, pontual e em contato], quanto à diferenciação funcional de células da polpa dentária humana, utilizando o ensaio de vermelho de Alizarina. Os dados foram submetidos à análise estatística adequada, considerando =0,05. Para PD e PS, não houve diferença significativa pós-EDTA (p>0,05). Pós-tratamento, todos os grupos apresentaram PD menor do que C (p0,05). Pós-ciclagem, os grupos C, BV e NP não diferiram significativamente quanto à PS, sendo maiores do que CXT (p0.05). Post-treatment, all groups had DP lower than C (p0.05). Post-cycling, groups C, BG and NP did not differ significantly in terms of dSL, being greater than CXT (p<0.05). SEM images showed occlusion of dentinal tubules through the formation of a layer over dentin specimens after application of treatments, except for the control group. After cycling, a partial removal of this layer was observed. Regarding the formation of mineralized nodules, within 7 days, there was no statistical difference between the experimental groups (p=0.397). After 14 days, the BG group showed greater mineralization potential, differing statistically from the negative control -MEM (p<0.05), but not from the other groups. After 21 days, the BG, Differentiation Medium (positive control), BG + PBM and CXT groups showed higher mineralization potential, with no statistically significant differences between them. It is concluded that BG was able to reduce dentin permeability after application, with a reduced effect after cycling, but it did not protect the dentin against erosive tooth wear. In addition, BG showed a potential for the formation of mineralized nodules after 14 and 21 days, however PBM did not improve its performance

Activated charcoal toothpastes do not increase erosive tooth wear.

OBJECTIVES To assess the effect of activated charcoal toothpastes on enamel and dentin erosive wear. METHODS Ninety enamel and dentin slabs were randomly distributed into 9 experimental groups (n = 10/substrate): Artificial saliva (negative control); Elmex Caries (EXC - 1400 ppm F- as AmF, reference toothpaste without charcoal); Colgate Luminous White Activated Charcoal (CLW - 1000 ppm F- as MFP); Colgate Natural Extracts (CNE - 1450 ppm F- as NaF); Oral-B 3D White Mineral Clean (OMC - 1100 ppm F- as NaF); Curaprox Black is White (CBW - 950 ppm F- as MFP); Bianco Carbon (BIC - no F-); Natural Suavetex (NSX - no F-); Oralgen Nupearl Advanced (ONA - no F-). Specimens were submitted to a 5-day erosion-toothbrushing abrasion cycling. Surface loss (SL) was determined with an optical profilometer. pH and concentration of available fluoride in the slurries were also assessed. Data were statistically analyzed (α = 0.05). RESULTS For both substrates, CBW, CNE and EXC had significantly lower SL values than the control. CLW and OMC promoted significantly less dentin wear than the control. All the other groups did not differ significantly from the control. There was a strong negative correlation between SL and concentration of fluoride in the slurries for enamel (r = -0.77) and dentin (r = -0.91), and a strong positive correlation (r = 0.77) between enamel SL and pH. CONCLUSIONS For both substrates, none of the activated charcoal-based toothpastes resulted in higher SL than brushing with artificial saliva. Only two of the charcoal toothpastes and the reference toothpaste were able to provide further protection against SL. CLINICAL SIGNIFICANCE Activated charcoal-containing toothpastes are becoming popular, despite the absence of evidence supporting their safety for use by individuals with erosive tooth wear. These products did not pose an additional risk for these subjects. However, it would be preferable to use products that exhibits further protective effect

Impact of different brushing/abrasion protocols on erosive tooth wear for in vitro studies.

OBJECTIVE To investigate the influence of different toothbrushing (with dentifrice) protocols on the progression of erosive tooth wear for in vitro studies. DESIGN Bovine enamel specimens were randomly distributed into 12 experimental groups (n = 10), according to the study factors: (1) brushing movement (horizontal or circular); (2) slurry diluent (artificial saliva or distilled water); (3) toothpaste dilution ratio (1:2, 1:3 or 1:4). A 5-day erosion-abrasion cycling model was performed, each consisting of 4 erosive challenges (0.3 % citric acid, pH=2.6) followed by 60 min exposure to artificial saliva. Brushing with fluoride toothpaste (15 s, 1400 ppm F-, AmF) was carried out 2x/day. Enamel surface loss (SL) was determined by optical profilometry. Data were statistically analyzed with three-way ANOVA and Tukey tests (α = 0.05). RESULTS SL was lower for the horizontal movement than for the circular (p = 0.044). There were no significant differences among the dilution ratios for artificial saliva. For distilled water, the more concentrated slurry (1:2) presented greater surface loss than the less concentrated slurries (1:3 and 1:4, p = 0.049 and p = 0.014, respectively). Dilutions with artificial saliva at ratios 1:3 and 1:4 presented higher surface loss than with distilled water (p = 0.008 and p < 0.001, respectively); however, for 1:2 ratio, there were no significant differences between the diluents. CONCLUSIONS The in vitro progression of enamel SL was influenced by the brushing movement, as well as the combination of the dilution ratio and the diluent of the toothpaste slurry, and therefore, all these factors must be considered when comparing results from different studies

Resin-based dental materials containing 3-aminopropyltriethoxysilane modified halloysite-clay nanotubes for extended drug delivery

OBJECTIVE: To synthesize and characterize a novel resin-based dental material containing 3-aminopropyltriethoxysilane (APTES) surface-modified halloysite-clay nanotubes (HNTs) for long-term delivery of guest molecules. METHODS: The optimal concentrations of HNT (10, 15, 20 wt.%) and silane (0, 2, 4 vol.%sil) to be incorporated into the resin-based materials were determined (15 wt.%HNT, 4 vol.%sil) after assessment of the mechanical properties (DC%, degree of conversion; FS, flexural strength; FM, flexural modulus; and UTS, ultimate tensile strength). The HNTsil-powder was loaded with chlorhexidine (CHX) to evaluate the effect of the silanization on drug release. Resin-discs were prepared for the following groups: RES (resin), HNT (resin+15 wt.%HNT), HNTsil (resin+15 wt.%HNT silanized), HNT-CHX (resin+15 wt.%HNT loaded with chlorhexidine), HNTsil-CHX (resin+15 wt.%HNTsil-CHX), and 0.2 vol.%CHX (resin+0.2 vol.%CHX solution). Specimens were stored in water for 1, 3, 5, 10, and 15 days at 37 °C. Aliquots from each time point and the final 15-day specimens were evaluated for the zone of inhibition (ZOI) against Streptococcus mutans. CHX release was analyzed using spectrophotometry at absorbance of 300 nm. Data were statistically analyzed (α = 0.05). RESULTS: All materials presented similar DC%. Reduced FS but increased FM was detected for 20 wt.%HNT-4%APTES. Groups with 15 wt.% and 20 wt.%HNT with/without APTES presented higher values of UTS. Agar diffusion data indicates that the HNTsil-CHX had a greater ZOI than all other groups over 15 days. HNTsil-CHX had the highest absorbance for day 1 but presented similar values to other groups every time point after. SIGNIFICANCE: Silanization of nanotubes followed by encapsulation of chlorhexidine is a promising technique for long-term delivery of guest molecules

Role of desensitizing/whitening dentifrices in enamel wear.

OBJECTIVES To analyze the impact of desensitizing (D) and/or whitening (W) dentifrices on erosion and erosion-abrasion. METHODS Enamel specimens were allocated into 10 groups (n = 20): 1. Artificial saliva (control); 2. Sensodyne Repair&Protect (SRP-D); 3. Sensodyne Repair&Protect Whitening (SRP-W); 4. Colgate Sensitive Pro-Relief (CSPR-D); 5. Colgate Sensitive Pro-Relief Real White (CSPRR-W); 6. Colgate Total 12 (CT); 7. Colgate Total 12 Professional Whitening (CTP-W); 8. Sensodyne True White (ST-W); 9. Curaprox Black is White (CB-W); 10. Oral-B 3D White Perfection (OB3D-W). For abrasion (n = 10), 30,000 brushing strokes were performed and surface roughness (SR) was evaluated. Erosion-abrasion (n = 10) consisted of 1 % citric acid (2 min), artificial saliva (60 min); 6×/day; 5 days. Toothbrushing was carried out 2×/day (45 strokes). Surface loss (SL) was determined with an optical profilometer. Data were statistically analyzed (α = 0.05). RESULTS Relative to SR, only OB3D-W had a significantly rougher surface than the control (p = 0.014). SRP-D, CSPR-D and ST-W showed no difference from the baseline. High SL was observed for ST-W, OB3D-W and CTP-W, without significant differences from the control. CT showed the lowest SL, not differing from SRP-D and SRP-W. There was a weak negative correlation between SL and concentration of free fluoride in the slurries, SL and SR, and SL and pH, all p > 0.05. CONCLUSIONS Only one dentifrice increased surface roughness of enamel to a higher degree than brushing with saliva. Brushing with the test dentifrices did not cause higher enamel erosive wear than brushing with saliva. CLINICAL SIGNIFICANCE This study enhances our knowledge on the effect of desensitizing and whitening dentifrices, indicating that they do not worsen enamel loss due to abrasion and they might be a safe option for individuals with erosive tooth wear

Impact of desensitizing/whitening toothpastes on tooth color change after abrasion and erosion-abrasion.

OBJECTIVE To evaluate the impact of desensitizing toothpastes (D), their whitening versions (DW) and whitening toothpastes (W) on tooth color change. METHODS Tooth specimens were allocated into 11 groups (n = 10): 1. Artificial saliva (control); 2. Sensodyne Repair & Protect (SRP-D); 3. Sensodyne Repair & Protect Whitening (SRP-DW); 4. Colgate Sensitive Pro-Relief (CSPR-D); 5. Colgate Sensitive Pro-Relief Real White (CSPR-DW); 6. Colgate Total 12 (CT12); 7. Colgate Total 12 Whitening (CT12-W); 8. Sensodyne True White (ST-W); 9. Curaprox Black Is White (CB-W); 10.Oral-B 3D White Perfection (OB3D-W) and 11. Erosion-only. They were submitted to two models: A. abrasion; B. erosion/abrasion. Color change (ΔE00 ), ΔL, Δa, and Δb were determined with a spectrophotometer. Data were statistically evaluated (α = 0.05). RESULTS For both models, ∆E00 of D did not differ significantly from DW. An overall decrease in luminosity (-∆L) and increase (+∆b) in yellowness of the tooth occurred. In abrasion, all groups reduced redness (-∆a) and only SRP-DW differed from control (p = 0.016), but for ∆E00 , ∆L and ∆b, all toothpastes did not differ from the control. In erosion/abrasion, CB-W showed significantly lower ∆E00 and ∆b than the control (∆E00 : p = 0.026; ∆b: p = 0.005) and SRP-D (∆E00 : p = 0.028; ∆b: p = 0.025). Only SRP-DW, CSPR-DW, ST-W, CB-W, and erosion-only had increased redness (+∆a), but none differed from control. CONCLUSIONS The toothpastes did neither promote whitening nor avoid the yellowish aspect of the tooth after abrasion and erosion-abrasion, regardless of their claim. CLINICAL SIGNIFICANCE Desensitizing and/or whitening toothpastes induced similar changes on tooth color, without promoting whitening effect or reduction in its yellowish aspect