Effects of Dentifrices With Antierosive Potential on the Surface of Bovine Enamel Submitted to Acidic Beverage.

OBJECTIVES: To evaluate the effects of dentifrices containing sodium fluoride (NaF) combined with NovaMin (Sensodyne Repair & Protect-SRP), NaF combined with stannous fluoride (SnF2, Oral-B Pro-Gengiva-OBP), and amine fluoride (AmF, Colgate Elmex-ELM) on enamel subjected to simulated erosive cycling. MATERIALS AND METHODS: Bovine enamel-dentin discs (n = 10/group) were subjected to erosive cycling with orange juice (pH = 3.29, 5 min, 3x/day), artificial saliva (SA-2 h, 3x/day and overnight) and treated with dentifrice (2 min, 2x/day) or without treatment (CONT). Surface microhardness (SMH) was evaluated at baseline (T0), on the first (T1) and fifth (T5) days. SMH loss (%SHL) was calculated. Surface roughness (Ra, µm) was determined at T0 and T5. Morphology and mineral content were evaluated under scanning electron microscopy and energy-dispersive x-ray spectroscopy. Data were analyzed using ANOVA/Tukey or Bonferroni (α = 5%). RESULTS: No differences in %SHL were detected among groups at T1. At T5, OBP promoted %SHL, Ra, and ΔRa significantly lower than all the other groups (p < 0.05). All groups exhibited morphological changes in topography and similar Ca/P means before and after treatments. CONCLUSIONS: Dentifrice containing SnF2 minimized the negative effects on the SMH and Ra caused by exposure to orange juice after 5 days of simulated cycling. CLINICAL RELEVANCE: Patients who are more exposed to risk factors for dental erosion could benefit from the use of dentifrice containing SnF2.

Remineralizing effect of the association of nano-hydroxyapatite and fluoride in the treatment of initial lesions of the enamel: A systematic review.

OBJECTIVE: Assessed the effect of dental products containing nano-hydroxyapatite (nano-HA) + fluoride on the remineralization of white spot lesions (WSL) in vivo or in situ. METHODS: Seven databases were explored using a two-pronged approach (intervention/treatment). After screening, full-text assessment, and further exclusion, the qualitative synthesis of five studies (four clinical and one in situ) was performed. Based on the Cochrane collaboration guidelines relevant data of the studies were collected and summarized. The Cochrane risk of bias tool for randomized trials (RoB 2.0) was used to appraise the studies' methodological quality and the GRADE guidelines to assess their level of evidence. The RoB 2.0 domains were rated on their risk of bias (RoB) as low, high, or with some concerns, and an adaptation of the tool was used to the in situ study. RESULTS: The included studies assessed 151 WSL in anterior permanent teeth, on patients with varying ages. The protocol application, treatment length (7d-12 w), and control groups varied greatly between the studies making the performance of a quantitative analysis unfeasible. The general RoB of the clinical studies was classified as being of low risk (n = 2) or some concerns (n = 2). The in situ study was considered as being of low risk. The level of the evidence was moderate. Most of the studies found moderate evidence regarding the superiority of this association in clinical settings. CONCLUSION: Even with the nano-HA + fluoride promising results for the remineralization treatment of WSL, due to the restricted number of studies and types of products, its extended use cannot be recommended based on the current systematic review, especially when considering the moderate level of the evidence found. CLINICAL SIGNIFICANCE: Due to the biocompatibility and higher surface coverage of nano-HA and the remineralization capacity of fluoride formulations, the association of these elements to remineralize WSL has been positively reported. After the collection and qualitative appraise of the data, the clinical evidence of the use of these dental products is promising but limited.

Xylitol associated or not with fluoride: Is the action the same on de- and remineralization?

OBJECTIVES: This study evaluated the effect of xylitol combined or not with fluoride (F) on reduction of demineralization and increase of remineralization of shallow and deep artificial enamel lesions. METHODS: Bovine enamel samples were allocated to the following solutions groups: no xylitol (negative control), 5% xylitol, 10% xylitol, 20% xylitol, 500 ppm F (as NaF), 5% xylitol+F, 10% xylitol+F or 20% xylitol+F (n = 12-15). For the demin study, a pH-cycling model (demineralization-6 h, pH 4.7/remineralization 18 h, pH 7.0) was employed for 7 days. Treatments were applied 2 × 1 min. In the remin study, specimens were pre-demineralized for 2, 5 or 10 days. Afterwards, a pH-cycling protocol was conducted (2 h demineralizing and 22 h remineralizing solution/day for 8 days) and the same treatments were done. The response variables were percentage surface hardness loss (%SHL) and transverse microradiography. Data were analyzed by RM ANOVA/Tukey or Kruskal-Wallis/Dunn (p < 0.05) RESULTS: F and Xylitol combined with F reduced the %SHL (23-30%) compared to the negative control (61.5%). The integrated mineral loss and the lesion depth were not reduced by any treatment. Surface hardness recovery was seen only for shallow lesions in case of 20% xylitol+F compared to negative control. No lesion depth recovery, but significant mineral recovery was seen for F (2-days and 10-days lesion). CONCLUSIONS: All concentrations of xylitol+F reduced enamel surface demineralization, while only 20% xylitol+F improved surface remineralization of shallow lesions in vitro. CLINICAL SIGNIFICANCE: Our results suggest that while F or any concentration of xylitol + F reduces surface demineralization, only 20% xylitol+F improves surface remineralization of shallow lesions in vitro. Therefore, xylitol may be added into oral products, combined to F, to control dental caries.

Remineralizing potential of a fluoride varnish modified by bioactive nanoparticles / Potencial remineralizante de um verniz fluoretado modificado por nanopartículas bioativas

Objective: Evaluate a fluoride varnish modified by nanostructures with the bioactive qualities of silica (SiO2) and niobium pentoxide (Nb2O5), testing its remineralizing potential by surface hardness (SH) and energy-dispersive X-ray spectroscopy (EDX). Material and Methods: Bovine enamel specimens (6×4×2mm) were prepared and submitted to a demineralizing/remineralizing process to produce a subsurface caries-like lesion, evaluated by transversal microradiography image (TMR) and subsequently distributed randomly into three groups: fluoride varnish (VZ); fluoride varnish + silica gelatin (VZ-SiO2) and fluoride varnish + niobium nanoparticles (VZ-Nb2O5). The specimens were subjected to a pH-cycling demineralizing/remineralizing process for 7 days at 37ºC. The %SH loss and %SH recovery (after the pH-cycling regimen) were calculated (n=10/group). The Ca/P weight ratio before and after the pH-cycling regimen was evaluated through SEM/EDX. A two-way ANOVA followed by Tukey's test (p<0.05) was performed for hardness and EDX. Results: TMR image showed the formation of an artificial subsurface lesion, and a significant SH increase was observed in the VZ-Nb2O5 group (p<0.05). Regarding the %SHL and %SHR, the VZ-Nb2O5 and VZ-SiO2 were significantly different compared to the VZ group (p<0.001), but VZ-Nb2O5 presented higher values. The Ca/P ratio showed that blocks treated with VZ-SiO2 and VZ-Nb2O5 showed greater ion deposition, particularly in the presence of Nb. Conclusion: The bioactivity of niobium facilitated greater interaction between the enamel and the varnish, leading to a slow release of nanoparticles and a longer-lasting remineralizing effect (AU)

Objetivo: Avaliar um verniz fluoretado modificado por nanoestruturas com a bioatividade da sílica (SiO2) e pentóxido de nióbio (Nb2O5), testando seu potencial remineralizador pela dureza de superfície (SH) e espectroscopia de energia dispersiva de raios-X (EDX). Material e Métodos: Espécimes de esmalte bovino (6×4×2mm) foram preparados e submetidos à desmineralização/remineralização para produzir uma lesão subsuperficial semelhante a cárie, avaliada por imagem de microrradiografia transversal (TMR) sendo distribuída em três grupos: verniz fluoretado (VZ); verniz fluoretado+gelatina de sílica (VZ-SiO2) e verniz fluoretado+nanopartículas de nióbio (VZ-Nb2O5). As amostras foram submetidas à desmineralização/remineralização por ciclagem de pH durante 7 dias a 37°C. A porcentagem de perda e recuperação de SH foram calculadas (n=10/grupo). A relação em peso Ca/P antes e depois da ciclagem foi avaliada através de MEV/EDX. ANOVA a dois critérios seguida do teste de Tukey (p<0,05) foi realizada para dureza e EDX. Resultados: A TMR mostrou a formação de uma lesão subsuperficial e um aumento significativo de SH foi observado no grupo VZ-Nb2O5 (p<0,05). Em relação ao %SHL e %SHR, o VZ-Nb2O5 e o VZ-SiO2 foram significativamente diferentes em relação ao grupo VZ (p<0,001), mas o VZ-Nb2O5 apresentou valores maiores. A relação Ca/P mostrou que os blocos tratados com VZ-SiO2 e VZ-Nb2O5 apresentaram maior deposição de íons, principalmente na presença de Nb. Conclusão: A bioatividade do nióbio facilitou maior interação entre o esmalte e o verniz, levando a uma liberação lenta de nanopartículas e a um efeito remineralizante mais duradouro (AU)

The Effect of Casein Phosphopeptide-Amorphous Calcium Phosphate Containing Bonding Agents on Dentin Shear Bond Strength and Remineralization Potential: An in Vitro Study

ABSTRACT Objective: To assess the effect of Casein Phosphopeptide-Amorphous Calcium Phosphate (ACP) containing bonding agents on dentin shear bond strength and remineralization potential. Material and Methods: This in vitro study evaluated 45 extracted human premolars. The teeth were decoronated, and the tooth crown was split into buccal and lingual halves. The specimens were then flat-grounded by a 180-grit abrasive. The specimens were then randomized into three groups (n=15). Adper Scotchbond Multi-Purpose (SBMP) primer and adhesive were used for bonding in the control group. ACP in 10wt% and 20wt% concentrations was added to SBMP adhesive and used in groups 2 and 3, respectively. After the application of primer and adhesive and light-curing them for 10 s, a transparent silicon cylinder was placed on a dentin surface and cured for 10 s; then, the cylinder was filled with composite resin and was cured for the 40s from each side. The specimens underwent 3000 thermal cycles, and a universal testing machine measured the SBS. To assess the remineralization quality, a total of 6 dentin samples (2 specimens for group) were prepared and underwent X-ray diffraction, attenuated total reflection Fourier-transform infrared spectroscopy, and scanning electron microscopy-energy dispersive X-ray analysis. One-way analysis of variance was used to analyze the data. The level of p<0.05 was considered significant. Results: No significant difference in dentin shear bond strength was noted between the groups (p>0.05) - the addition of ACP to SBMP adhesive enhanced dentin remineralization. Increasing the ACP concentration from 10% to 20% increased the formation of hydroxyapatite. Conclusion: Adding amorphous calcium phosphate confers remineralizing property to SBMP adhesive without compromising its shear bond strength to dentin.

Inhibition of incipient caries lesion progression by different fluoridated varnishes

Abstract The aim of this in vitro study was to evaluate the potential of different fluoridated varnishes to inhibit the progression of incipient caries lesions after cariogenic challenge. Seventy-five enamel specimens of bovine teeth were prepared and selected based on the initial surface microhardness (SMH). The specimens were first subjected to artificial demineralization (in buffer solution) after which SMH was re-analyzed (SM1). They were then randomly assigned to five experimental groups: 1- CONTROL (pH cycling), 2 - MI VAR (MI Varnish with RECALDENTTM - CPP-ACP), 3 - PROFL (Profluorid®), 4 - CLIN (ClinproTM White Varnish with TCP), and 5 - DUR (Duraphat®) (n=15). The varnishes were applied in a thin layer and the specimens were then subjected to pH cycling for eight days. The SMH and cross-sectional microhardness (CSMH) were then analyzed (SM2). The fluoride and calcium ion concentrations in the solution were analyzed by the indirect method and atomic absorption spectrophotometry, respectively. Data were statistically analyzed by Student's t-test, ANOVA/Tukey-Kramer, or Kruskall-Wallis/Dunn tests for individual comparisons (p˂0.05). All varnishes led to significantly higher surface and subsurface remineralization compared with the control group but did not differ from each other. The varnishes with the highest fluoride release were: PROFL and CLIN, followed by MI VAR and DUR. The varnishes with significantly higher release of calcium were: DUR, CLIN, and PROFL. In conclusion, all commercial fluoridated varnishes tested have good potential to inhibit the progression of demineralization, regardless of the ion release mechanisms.

Resumo O objetivo deste estudo in vitro foi avaliar o potencial de diferentes vernizes fluoretados em inibir a progressão de lesões de cárie incipientes. Setenta e cinco espécimes de esmalte de dentes bovinos foram preparados e selecionados com base na microdureza superficial inicial (MDS/SM). Os espécimes foram submetidos à desmineralização artificial (em solução de Buskes), sendo então a MDS (SM1) reanalisada. Foram então distribuídos aleatoriamente em cinco grupos experimentais: 1- CONTROLE (pH cycling), 2 - MI VAR (MI Varnish with RECALDENTTM - CPP-ACP), 3 - PROFL (Profluorid®), 4 - CLIN (ClinproTM White Varnish with TCP), and 5 - DUR (Duraphat®). Os vernizes foram aplicados em camada fina e os espécimes foram então submetidos à ciclagem de pH por oito dias. A MDS final (SM2) e a microdureza transversal (CSMH) foram então analisadas. As concentrações de flúor e íons cálcio em solução foram analisadas pelo método indireto e espectrofotometria de absorção atômica, respectivamente. Os dados foram analisados estatisticamente pelo teste T de Student, ANOVA/Tukey-Kramer ou testes de Kruskall-Wallis/Dunn para comparações individuais (p˂0,05). Todos os vernizes levaram a uma remineralização superficial e subsuperficial significativamente maior em comparação com o grupo controle, não diferindo significativamente entre si. Os vernizes com maior liberação de flúor foram: PROFL e CLIN, seguidos de MI VAR e DUR. Os vernizes com liberação significativamente maior de cálcio foram: DUR, CLIN e PROFL. Pôde-se concluir que todos os vernizes fluoretados comerciais testados apresentam bom potencial de inibição da progressão da desmineralização, independentemente dos mecanismos de liberação de íons.

Remineralization of white spot lesions in orthodontic. is that possible? Literature review / Remineralização de lesões de mancha branca em Ortodontia. Isso é possível? Revisão de literatura

Aim: The aim of this literature review is to describe the latest treatment available in the solution of this problem through remineralization. Literature review: A literature review was carried out in various electronic databases such as PubMed, MEDLINE, EBSCO, LILACS, EMBASE, Cochrane Library; from 1989 to 2022. The Medical Subject Headings (MeSH) terms used in the literature search were in English: "tooth reminaralization", "dental white spot", "orthodontic. Discussion: White spot lesions after orthodontic appliances is an undesired effect seen in dentistry. There is a wide option of agents that offer remineralization by the process of depositing calcium and phosphate ions into crystal voids in demineralized enamel, producing net mineral gain and preventing early enamel lesions progression, including fluoride toothpastes, fluoride varnishes, fluoride mouth rinses, and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). Conclusion: Fluoride-based prevention strategies are the agent with the strongest evidence for the treatment of WSL. The dental professional should offer this therapy in the earliest phase of the lesions so that it can be remineralized.

Objetivo: O objetivo desta revisão de literatura é descrever osmais recentestratamentos disponíveisna remineralizaçãode lesões de mancha branca.Revisão da literatura: Foi realizada uma revisão da literatura em várias bases de dados eletrônicas como PubMed, MEDLINE, EBSCO, LILACS, EMBASE, Cochrane Library; de 1989 a 2022. Os termos do Medical Subject Headings (MeSH) utilizados na busca da literatura foram em inglês: "tooth reminaralization", "dental white spot", "orthodontics".Discussão: A lesão de mancha branca após utilização de aparelhos ortodônticos é um efeito indesejado observado na odontologia. Existe uma ampla opção de agentes que oferecem remineralização pelo processo de deposição de íons cálcio e fosfato nos cristaisdo esmalte desmineralizado, produzindoganho mineral líquido e prevenindo a progressão precoce das lesões do esmalte, incluindo cremes dentais com flúor, vernizes com flúor, enxaguatórios bucaiscom flúor e caseína fosfopeptídeo-fosfato de cálcio amorfo (CPP-ACP).Conclusão: As estratégias de prevenção utilizandoflúor constituem osagentescom mais evidências para o tratamento da mancha branca. O dentista deve oferecer essa terapia na fase inicial das lesões para que haja remineralização.

Poly(Aspartic Acid) Promotes Odontoblast-like Cell Differentiation in Rat Molars with Exposed Pulp.

In recent years, alternative pulpal therapies targeting dentinogenesis signaling pathways using different peptides have been investigated. The aim of this study was to verify the effectiveness of poly(aspartic acid), pAsp, in dentin regeneration using an animal model. METHODS: Mechanical pulp exposure was performed in the upper molars of 56 Wistar rats, randomly divided as follows (n = 14): control (no treatment); MTA group-pulp capping with mineral trioxide aggregate (MTA Angelus); pAsp group-application of 20 µL of pAsp solution (25 mg·mL-1); MTA+pAsp group-application of MTA mixed with pAsp (5:1 by mass). Animals were euthanized after 7 or 21 days. Histological sections were submitted to hematoxylin-eosin and Brown and Brenn staining and immunohistochemical analysis for osteopontin (OPN) and dentin matrix protein 1 (DMP 1). RESULTS: At 7 days, an acute inflammatory infiltrate and the presence of disorganized mineralized tissue were observed in all groups. At 21 days, the quality and thickness of the reparative dentin in treated groups were superior to the control, and bacterial contamination was observed in two MTA-pAsp specimens. While all treated groups showed intense immunostaining for OPN at 21 days, only the pAsp group expressed DMP 1, indicating the presence of fully differentiated odontoblast-like cells. CONCLUSION: Poly(aspartic) acid promoted dentin regeneration in rat molars in the absence of an additional calcium source and may be an alternative to MTA as a pulp-capping agent.

Regenerative and Protective Effects on Dental Tissues of a Fluoride-Silicon-Rich Toothpaste Associated with a Calcium Booster: An In Vitro Study.

Calcium boosters have been used as a supplement for fluoride toothpastes to repair the dental tissues and reduce dentin permeability. This in vitro study aimed to characterize the regenerative and protective effects of the treatment of dental tissues with a fluoride-silicon-rich toothpaste associated with a calcium booster. Bovine enamel and dentin blocks (n = 5) were obtained (4 × 4 × 6 mm). A fluoride-silicon-rich toothpaste and a calcium booster were used to brush the enamel and dentin both immediately and five days afterwards. The outcomes were then compared to those of the untreated control group. After that, the specimens were cross-sectioned. SEM was used to evaluate the micromorphology of the surface and cross-section. Energy-dispersive X-ray spectroscopy (EDS) was used to determine the elemental analyses (weight%). After treatment for 5 days with a booster/silicon-rich toothpaste, EDS analysis demonstrated that it induced a significant mineral change. It was also able to form a protective silicon-enriched mineral layer on both enamel and dentin surfaces. It was demonstrated in vitro that a fluoride-silicon-rich toothpaste associated with a calcium booster regenerates the dental tissues, remineralizing the enamel structure and occluding the dentin tubules.

Orthodontic resins loaded with niobium silicate particles: Impact of filler concentration on the physicochemical and biological properties.

OBJECTIVES: White spot lesions (WSL) are prevalent in patients using orthodontic appliances. The presence of ion-releasing compounds in the tooth-appliance interface may limit enamel demineralization to control WSL incidence. Thus, this study aims to evaluate the mineral formation on SiNb-containing experimental orthodontic resins and the influence of these fillers on the physicochemical and biological properties of developed materials. MATERIALS AND METHODS: The SiNb particles were synthesized via the sol-gel route and characterized by their molecular structure and morphology. Photopolymerizable orthodontic resins were produced with a 75 wt% Bis-GMA/25 wt% TEGDMA and 10 wt%, 20 wt%, or 30 wt% addition of SiNb. A control group was formulated without SiNb. These resins were tested for their degree of conversion, softening in solvent, cytotoxicity in fibroblasts, flexural strength, shear bond strength (SBS), and mineral deposition. RESULTS: The addition of 10 wt% of SiNb did not impair the conversion of monomers, cytotoxicity, and flexural strength. All groups with SiNb addition presented similar softening in solvent. The presence of these particles did not affect the bond strength between metallic brackets and enamel, with SBS values ranging from 16.41 to 18.66 MPa. The mineral deposition was observed for all groups. CONCLUSION: The use of niobium silicate as filler particles in resins may be a strategy for the adhesion of orthodontic appliances. The 10 wt% SiNb concentration resulted in a material with suitable physicochemical and biological properties while maintaining the bond strength to tooth enamel and promoting mineral deposition.

Effectiveness of non-operative approaches in active enamel carious lesions: a retrospective longitudinal study

Abstract The aim of the study was to investigate the effectiveness of non-invasive and micro-invasive treatments in active enamel carious lesions in high-caries-risk children. Clinical records of children treated in a dental school setting were retrospectively screened for active enamel carious lesions treated non-invasively (topical fluoride applications, oral hygiene instruction, or dietary guidance) or micro-invasively (sealant). The control of active carious lesions was set as the main outcome established by the combination of inactivation and non-progression of the lesions based on Nyvad and ICDAS criteria, respectively. Individual and clinical factors associated with the outcome were analyzed by Poisson regression. The sample consisted of 105 high-caries-risk children with a mean age of 8.3 (± 2.4) years. From a total of 365 active enamel carious lesions, most lesions (84.1%) were active non-cavitated carious lesions (ICDAS scores 1 and 2) and only 15.9% presented localized enamel breakdown (ICDAS score 3). Of these, 72.6% were inactivated and 92.1% did not progress (mean time of 6.5 ± 4.1 months). The prevalence of controlled carious lesions was higher among children older than 6 years (PR:1.43; 95%CI:1.00-2.03; p = 0.04) and in those with better biofilm control (PR:0.99; 95%CI: 0.98-0.99; p = 0.03). Non-operative approaches are effective for controlling active enamel carious lesions. The majority of active enamel carious lesions became inactive and did not progress after treatment. Caries control was associated with older children and better biofilm control.

Effect of phenylmethylsulfonyl fluoride, a protease inhibitor, on enamel surface remineralization

Phenylmethylsulfonyl fluoride (PMSF) is a protease inhibitor widely used in research, but fluoride is released during its action and this knowledge has been neglected in dental research. Aim: to evaluate if fluoride released by salivary protease action on PMSF affects enamel remineralization and fluoride uptake. Methods: Groups of 10 enamel slabs, with caries-like lesions and known surface hardness (SH), were subjected to one of the following treatment groups: Stimulated human saliva (SHS), negative control; SHS containing 1.0 µg F/mL (NaF), positive control; and SHS containing 10, 50 or 100 µM PMSF. The slabs were subjected to a pH-cycling regimen consisting of 22 h/day in each treatment solution and 2 h/day in a demineralizing solution. After 12 days, SH was again measured to calculate the percentage of surface hardness recovery (%SHR), followed by enamel fluoride uptake determination. The time-related fluoride release from 100.0 µM PMSF by SHS action was also determined. Data were analyzed by ANOVA followed by Newman-Keuls test. Results: The release of fluoride from PMSF by SHS was rapid, reaching a maximum value after 10 min. Fluoride released from PMSF was more effective in enhancing %SHR and increasing fluoride uptake in enamel compared with SHS alone (p < 0.05); furthermore, it was equivalent to the positive control (p > 0.05). Conclusion: In conclusion, fluoride released by saliva from PMSF is available to react with enamel and needs to be taken into account in research using this protease inhibitor

Potencial protetor de dentifrícios contendo partículas S-PRG contra o desgaste dental erosivo / Potential protector of toothpastes containing S-PRG fillers against erosive dental wear

Novas alternativas de tratamento têm surgido para se reduzir a desmineralização dental, como o uso de materiais com propriedade bioativa. As partículas de vidro com superfície pré-reagida (S-PRG) tem o potencial de liberação de íons, alumínio, boro, flúor, sódio, silício e estrôncio, podendo representar uma proposta promissora contra a desmineralização ocasionada na erosão dental. Assim, neste trabalho, propusemo-nos avaliar se dentifrícios experimentais contendo diferentes concentrações de partículas S-PRG oferecem potencial protetor contra a erosão inicial e o desgaste dental erosivo/abrasivo do esmalte dentário. Espécimes em esmalte bovino foram preparados, polidos e alocados aleatoriamente em grupos (n = 10) conforme a concentração de S-PRG no dentifrício: 0% S-PRG; 1% S-PRG; 5% S-PRG; 10% S-PRG 20% S-PRG; 30% S-PRG. A água ultrapura e o dentifrício fluoretado (1450 ppm F-) foram controles negativo e positivo, respectivamente. Foram realizadas ciclagens erosivas/abrasivas, que consistiram na imersão em ácido cítrico a 0,3% (5 min ­ 4x/dia) seguidos por saliva humana. Os tratamentos com as suspensões de dentifrícios (1:3 com saliva artificial) foram realizados 2x/dia ­ 2 min. Os espécimes foram submetidos à abrasão em máquina de escovação (15 s ­ 200 g) durante a imersão nas suspensões de tratamento. As ciclagens foram repetidas por 5 dias. Inicialmente foram realizadas leituras de microdureza Knoop e perfilometria de contato. No primeiro dia do ciclo, a microdureza dos espécimes foi mensurada após o primeiro desafio ácido (E1), após os tratamentos para avaliar o potencial de reendurecimento (T) e após o segundo desafio ácido para avaliar o potencial protetor contra a desmineralização (E2). Após a finalização da ciclagem (5 dias), foi avaliada a perda de superfície do esmalte por meio de perfilometria. Os dados foram submetidos ao teste ANOVA a um fator e teste post hoc de Tukey (α = 0.05). Os dados de microdureza mostraram diferenças significantes para os diferentes grupos testados, tanto em relação potencial de reendurecimento (p<0,001) e de redução de alteração da dureza (p<0,001). Os valores médios de perda superficial do esmalte foram: Água (11,24±1,22a); NaF (6,43±0,83c); 0% (10,96±0,97a); 1% (10,26±1,01a); 5% (8,66±0,46b); 10% (6,62 ±0,64c); 20% (4,65±0,92d); 30% (4,05±0,74d); (letras diferentes significam diferença significante pelo teste de Tukey). Conclui-se que os dentifrícios contendo partículas de S-PRG em maiores concentrações (10% a 30%) tiveram resultados favoráveis no potencial de reendurecimento, na redução de alteração, e diminuição do desgaste dental erosivo, sendo que na concentração de 30%, o efeito foi superior ao observado pelo dentifrício fluoretado.(AU)

New treatment alternatives have emerged to reduce dental demineralization, such as the use of materials with bioactive properties. Glass particles with a pre-reacted surface (S-PRG) have the potential to release ions, aluminum, boron, fluorine, sodium, silicon and strontium, and may represent a promising proposal against demineralization caused by dental erosion. Thus, in this study, we aimed to evaluate whether experimental dentifrices containing different concentrations of S-PRG particles offer protective potential against initial erosion and erosive/abrasive tooth wear of dental enamel. Bovine enamel specimens were prepared, polished and randomly allocated into groups (n = 10) according to the concentration of S-PRG in the dentifrice: 0% S-PRG; 1% S-PRG; 5% S-PRG; 10% S-PRG 20% S-PRG; 30% SPRG. Ultrapure water and fluoridated dentifrice (1450 ppm F-) were negative and positive controls, respectively. Erosive/abrasive cycling was performed, consisting of immersion in 0.3% citric acid (5 min - 4x/day) followed by human saliva. Treatments with dentifrice suspensions (1:3 with artificial saliva) were performed 2x/day - 2 min. Specimens were subjected to abrasion in a brushing machine (15 s - 200 g) during immersion in the treatment suspensions. Cycling was repeated for 5 days. Initially, Knoop microhardness and contact profilometry readings were performed. On the first day of the cycle, the microhardness of the specimens was measured after the first acid challenge (E1), after the treatments to evaluate the re-hardening potential (T) and after the second acid challenge to evaluate the protective potential against demineralization (E2). After completion of cycling (5 days), enamel surface loss was assessed by means of profilometry. Data were submitted to one-way ANOVA and Tukey's post hoc test (α = 0.05). The microhardness data showed significant differences for the different groups tested, both in terms of re-hardening potential (p<0.001) and reduction in hardness change (p<0.001). The mean values of enamel surface loss were: Water (11.24±1.22a); NaF (6.43±0.83c); 0% (10.96±0.97a); 1% (10.26±1.01a); 5% (8.66±0.46b); 10% (6.62±0.64c); 20% (4.65±0.92d); 30% (4.05±0.74 d); (different letters mean significant difference by Tukey's test). It is concluded that dentifrices containing S-PRG particles in higher concentrations (10% to 30%) had favorable results in the re-hardening potential, in the reduction of alteration, and reduction of erosive tooth wear, and at the concentration of 30%, the effect was superior to that observed by fluoridated dentifrice (AU)

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.

Effect of an experimental chitosan/casein gel on demineralized enamel under a cariogenic challenge.

BACKGROUND: Dental caries is considered one of the most common oral health diseases. OBJECTIVES: The aim of the study was to evaluate the effects of an experimental chitosan/casein gel on enamel demineralization/remineralization in an environment with a high cariogenic challenge. MATERIAL AND METHODS: Thirty-six specimens of bovine enamel (4 mm × 3 mm × 2 mm) were ground flat and polished. Then, the specimens were immersed in acetate buffer for 43 h with half of the surface protected (serving as control) and the other half exposed. All demineralized surfaces were randomly assigned into 3 groups (n = 12 per group) according to the type of treatment (G1 - control, G2 - 1.5% chitosan gel with 1.5% casein, and G3 - 1.5% chitosan gel without casein), and the corresponding treatment was applied once a week for 3 weeks. The specimens were also subjected to pH cycles of demineralization/ remineralization and the treatments were performed 3 times at 7-day intervals for a total of 21 days. Surface images were obtained for the analysis of initial roughness and, after the cariogenic challenge, new images were obtained to evaluate the final roughness, volume loss and wear profile using laser confocal microscopy. After the analyses, the specimens were cut and the depth of demineralization was measured. The data were analyzed using the Kruskal-Wallis analysis of variance (ANOVA) and the Tukey's test. RESULTS: While the chitosan gel with casein showed a similar loss to the control group (p > 0.05), both gels resulted in similar volume loss (p > 0.05). There were no statistical differences regarding the wear profile, surface roughness and depth of demineralization between the groups (p > 0.05). CONCLUSIONS: The chitosan gel reduced volume loss of the demineralized enamel without significantly impacting the surface smoothness.

Effectiveness of fluoride-containing toothpastes associated with different technologies to remineralize enamel after pH cycling: an in vitro study.

BACKGROUND: To evaluate the efficacy of fluoride-containing toothpastes with different technologies to remineralize artificial caries lesions in enamel. METHODS: Bovine enamel blocks were divided into three thirds: intact (untreated), demineralized (artificial caries lesion), and treated (caries lesion, pH cycling with dentifrices). Enamel blocks were randomly distributed into five groups (n = 12): Fluoride-free toothpaste, Colgate Oral Care (NC); Arginine-containing toothpaste, Colgate Total Daily Repair (PC); Silicate-based fluoride toothpaste: REFIX technology, regenerador + sensitive (RDC), NR-5 technology, Regenerate Enamel Science (RES), and NOVAMIN technology, Sensodyne Repair and Protect (SRP). The specimens were submitted to a pH cycling model for 6 days. The efficacy of the toothpastes was estimated by calculating the surface microhardness recovery (%SMHR) and the fluorescence recovery (ΔFRE) with quantitative light-induced fluorescence. The cross-sectional micromorphology of the enamel surface was also assessed using scanning electron microscopy. Elemental analyses (weight%) were determined with an energy-dispersive X-ray spectrometer (EDS). The results were compared to that of the control (NC). Data were statistically analyzed (5%). RESULTS: %SMHR could be ranked as follows: RDC = PC = RES = SRP > NC. Significantly higher %SMHR and ΔFRE means were observed after enamel treatment with RDC (22.7 and 46.9, respectively). PC (%SMHR = 18.8) was as efficacious as RDC to recover the surface microhardness with a significantly lower mean of ΔFRE (19.5). Only RDC was able to promote the formation of a mineralized layer on the surface of enamel enriched with silicon on the surface. CONCLUSIONS: The silicate-based fluoride toothpaste containing REFIX technology demonstrated greater efficacy in the remineralizing artificial caries than the other products.

Nano-hydroxyapatite-induced remineralization of artificial white spot lesions after bleaching treatment with 10% carbamide peroxide.

OBJECTIVE: To assessed in vitro the effect of nanohydroxyapatite (n-HA) to improve the aesthetic appearance and microhardness of white spot lesions (WSL) when associated with a low-concentration bleaching agent (carbamide peroxide-CP10%). MATERIAL AND METHODS: Enamel/dentin specimens (n = 60) of 5 × 5 × 2.2 mm were prepared, of these, 48 were submitted to pH-cycling to create artificial WSL. Subsequently, these were allocated into five groups (n = 12): n-HA; n-HA + CP10%; CP10%; WSL control (WSLC ); sound control (Sound). The color was assessed at baseline, pre-treatment, and post-treatment using a spectrophotometer, and the color (ΔE/ΔE00 ) and whiteness index (ΔWID) alterations were determined. The enamel cross-sectional microhardness (CSMH) was evaluated (post-treatment) with a Knoop indenter, 25gf/5 s, 20-200 µm. The data was analyzed through generalized linear models (α = 5%). RESULTS: ΔE and ΔE00 were significantly higher for the bleached groups (n-HA + CP10% and CP10%), and the n-HA was higher than the WSLC group (p < 0.05). ΔWID was significantly higher for the bleached groups (p < 0.05). The CSMH values were significantly higher in the sound group than in the n-HA, CP10%, and WSLC groups (p < 0.05). The WSLC had lower microhardness than the n-HA + CP10% and sound groups (p < 0.05). CONCLUSION: n-HA is suitable to remineralize and recover the color of the WSL. However, its association with CP10% maintains the esthetical outcome while increasing its in-depth remineralizing effect. CLINICAL SIGNIFICANCE: Considering the aesthetic and functional repercussions of the WSL persistence, treatments that tend to improve its physical appearance and reinforce its weakened substructure in a non-invasive way are ideal. For this associating low-concentration, bleaching agents to the remineralizing treatments is promising to treat this type of lesions.

Effect of a Toothpaste Containing Surface Pre-Reacted Glass-Ionomer Filler on the Remineralization of Artificial Carious Enamel Lesions in situ.

This study evaluated the remineralizing effect of a toothpaste containing surface pre-reacted glass-ionomer (S-PRG) filler on demineralized enamel in situ. For this, 180 bovine enamel samples were demineralized by using a microcosm biofilm model for 3 days. Thereafter, the samples were randomly signed to 15 healthy volunteers and to 3 cross-over in situ phases corresponding to the following treatments: (1) toothpaste containing 1,500 ppm F as NaMFP (positive control, Colgate®Cavity Protection), (2) toothpaste containing 5% S-PRG filler (Shofu®), and (3) placebo toothpaste (negative control prepared by Shofu®). Four demineralized enamel blocks were fixed into each palatal appliance per phase. The volunteers wore the appliances for 5 days and were trained to brush their teeth 2 times for 2 min a day, while one drop of the toothpaste's slurry (1:3) was dripped on each sample for the same period. The surface hardness and TMR analyses were done and analyzed by ANOVA/Tukey and t test (p < 0.05). S-PRG filler and Colgate® toothpastes were equally able to improve 2-2.5× enamel remineralization by the analysis of % surface hardness recovery. However, S-PRG toothpaste was the only one able to significantly improve ΔΔZ (the integrated mineral loss recovery: 1,489 ± 503 %vol.µm) compared to placebo (1,050 ± 467 %vol.µm), while Colgate® did not differ from placebo. No differences were seen between the groups with respect to ΔLD. S-PRG filler and Colgate® toothpastes show similar potential to remineralize the lesion surface. However, S-PRG toothpaste is better to recover mineral loss at the subsurface area.

Effect of a Self-Assembly Peptide on Surface Roughness and Hardness of Bleached Enamel.

After bleaching, enamel surfaces are damaged, contributing to erosion and tooth sensitivity. Although fluoride is used after bleaching to try and revert alterations, it is not capable of repairing tooth structure. This study compared the effect of a self-assembly peptide (P11-4), with and without fluoride, and sodium fluoride (NaF 2%) on the Knoop microhardness (KHN) and surface roughness (Ra (µm)) of bleached enamel with an in-office bleaching regimen. Enamel blocks of bovine teeth (5 × 5 × 2 mm) with standardized surface hardness were bleached with 35% carbamide peroxide, following the manufacturer's instructions. The teeth were randomly divided into the following groups (n = 7) according to post-bleaching treatment: no treatment (negative control) (C-); 2% NaF (NaF); Curodont™ Repair (Repair); and Curodont™ Protect (Protect). Specimens were stored in artificial saliva at 37 °C. To evaluate the effect of the post-bleaching treatments, KHN and Ra were measured before bleaching (baseline) and 24 h and 7 days after bleaching. Data were submitted to repeated measures ANOVA and Bonferroni tests (α = 0.05). There were significant interactions between the study factors (p = 0.001). After 7 days, Repair (572.50 ± 79.04) and Protect (583.00 ± 74.76) specimens showed increased surface KHN, with values higher than the NaF (465.50 ± 41.50) and C- (475.22 ± 58.95) baseline values. There was no significant difference in KHN at 24 h among groups (p = 0.587). At 24 h after bleaching, Repair was significantly different from all groups (p < 0.05). Repair showed the lowest Ra (µm) values (0.133 ± 0.035). After seven days, there was no significant difference in Ra values among groups when compared to the baseline. The use of P11-4-based materials after bleaching resulted in the fastest recovery to baseline enamel properties.

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.