Exploring the role of flavonoids in caries-affected dentin adhesion: A comprehensive scoping review.

OBJECTIVES: The aim of this scoping review was to evaluate the available scientific evidence regarding the use of flavonoids in the treatment of caries-affected dentin focusing on bonding to dentin. METHODS: A comprehensive literature search was performed in five databases from March 2022 and updated in April 2023: PubMed, EMBASE, Scopus, Web of Science, and Scielo. Additionally, the references of included studies were manually searched. Gray literature was excluded from the review. STUDY SELECTION: Inclusion criteria included in vitro, in situ, and in vivo studies (animal or human) published in English. Abstracts, reviews, case reports, book chapters, doctoral dissertations, guidelines, and studies using pure plant extracts were excluded. Data collected from the selected studies were summarized and subjected to narrative and descriptive analysis. Out of the 91 studies identified, only 16 studies met the inclusion criteria. RESULTS: The review analyzed eight different flavonoids (hesperidin, galardin, proanthocyanidin, genipin, quercetin, naringin, epigallocatechin-3-gallate, and other catechins subtypes) used as pretreatment or loaded into adhesive systems, primers, and phosphoric acid. The use of flavonoids improved the mechanical properties of the materials and modified the biological properties of the dentin, reducing collagen loss by the inhibition of proteolytic activity of matrix metalloproteinases (MMPs). CONCLUSIONS: Based on the findings of this scoping review, it can be concluded that the use of flavonoids as pretreatment or incorporation into dental materials preserves collagen in the hybrid layer, inhibiting the MMPs activities, modifying the collagen fibrils of the dentin matrix and improving the mechanical properties of the dental adhesive systems. Therefore, it represents a promising approach for promoting dentin biomodification. This can result in more stable bonding of adhesive restorations to caries-affected dentin.

Teaching pulpectomy in paediatric dentistry: A national cross-sectional survey of dental schools in Brazil.

BACKGROUND: Pulpectomy is used to treat primary teeth with irreversibly inflamed or necrotic pulp tissue. There is, however, a lack of consensus on clinical protocols for teaching pulpectomy at dental schools. AIM: To determine what faculty members at Brazilian dental schools are teaching about pulpectomy in primary teeth. DESIGN: A cross-sectional, observational study was conducted using a 39-question survey available via the Google Forms® platform. A snowball sampling strategy was used for recruitment. Invitations to participate were sent via e-mail, WhatsApp® and Instagram®. The data were analysed descriptively. RESULTS: A total of 177 (58.4%) responses were obtained. Most faculty members recommended the use of Kerr hand files (66.1%), and 1% sodium hypochlorite was the most common choice for the irrigating solution (35.3%). Iodoform pastes were the first choice of faculty members (41.6%), and 60.5% of the faculty members recommended composite resin as the definitive restoration. CONCLUSION: Similarities were found in the teaching of pulpectomy for primary teeth among faculty members at dental schools in Brazil.

Mechanical stress distribution over the palate by different pacifiers assessed by finite element analysis and clinical data.

The mechanical behavior of each type of pacifier on rigid structures and their various impacts on orofacial growth have yet to be discovered. The study aimed to evaluate the stress distribution over a child's palate by three types of pacifiers using finite element analysis and clinical and laboratory data. Modulus of elasticity was obtained from 30 specimens comprising 10 of each conventional (A), orthodontic (B), and breast-shaped (C) pacifiers. Tongue strength was assessed in eight 3-year-old children (kPa). A hemi-maxilla model was obtained from 2- to 3-year-old skull tomography, and the images of pacifiers A, B, and C were captured using 3D scanning. The Hypermesh® program generated a mesh of 6-node tetrahedral elements for applying forces in the X, Y, and Z directions to enable a nonlinear analysis. Pacifier B exhibited the highest values for distributed stress on the palate, followed by pacifier A. Pacifier B stimulated the maxilla forward and sideways. In contrast, pacifier A promoted a forward and upward load, favoring a more atresic palate. Pacifiers A and B tended to rotate in the sagittal plane, generating tensions in the anterior incisors and favoring the open bite. Pacifier C exhibited lateral expansion by stress induction over the mid-palatal suture with less influence on incisor inclination. Pacifiers showed different detrimental stress distributions on the palate. This information can be helpful for improving recommendations given to parents.

Effect of Biosilicate® Addition on Physical-Mechanical and Biological Properties of Dental Glass Ionomer Cements.

This study investigated the influence of incorporating Biosilicate® on the physico-mechanical and biological properties of glass ionomer cement (GIC). This bioactive glass ceramic (23.75% Na2O, 23.75% CaO, 48.5% SiO2, and 4% P2O5) was incorporated by weight (5%, 10%, or 15%) into commercially available GICs (Maxxion R and Fuji IX GP). Surface characterization was made by SEM (n = 3), EDS (n = 3), and FTIR (n = 1). The setting and working (S/W time) times (n = 3) and compressive strength (CS) were analyzed (n = 10) according to ISO 9917-1:2007. The ion release (n = 6) was determined and quantified by ICP OES and by UV-Vis for Ca, Na, Al, Si, P, and F. To verify cell cytotoxicity, stem cells from the apical papilla (SCAP) were exposed to eluates (n = 3, at a ratio of 1.8 cm2/mL) and analyzed 24 h post-exposure. Antimicrobial activity against Streptococcus mutans (ATCC 25175, NCTC 10449) was analyzed by direct contact for 2 h (n = 5). The data were submitted for normality and lognormality testing. One-way ANOVA and Tukey's test were applied for the working and setting time, compressive strength, and ion release data. Data from cytotoxicity and antimicrobial activity were submitted for Kruskal-Wallis' testing and Dunn's post hoc test (α = 0.05). Among all experimental groups, only those with 5% (wt) of Biosilicate® showed better surface quality. Only M5% showed a comparable W/S time to the original material (p = 0.7254 and p = 0.5912). CS was maintained for all Maxxion R groups (p > 0.0001) and declined for Fuji IX experimental groups (p < 0.0001). The Na, Si, P, and F ions released were significantly increased for all Maxxion R and Fuji IX groups (p < 0.0001). Cytotoxicity was increased only for Maxxion R with 5% and 10% of Biosilicate®. A higher inhibition of S. mutans growth was observed for Maxxion R with 5% of Biosilicate® (less than 100 CFU/mL), followed by Maxxion R with 10% of Biosilicate® (p = 0.0053) and Maxxion R without the glass ceramic (p = 0.0093). Maxxion R and Fuji IX presented different behaviors regarding Biosilicate® incorporation. The impacts on physico-mechanical and biological properties were different depending on the GIC, but therapeutic ion release was increased for both materials.

The Self-assembling peptide P11-4 influences viability and osteogenic differentiation of stem cells of the apical papilla (SCAP).

OBJECTIVE: To analyze the effect of P11-4 self-assembly peptide on cell viability and osteogenic capacity of SCAPs through mineral deposition and gene expression of osteogenic markers. METHODS: SCAPs were seeded in contact with P11-4 (10 µg/ml, 100 µg/ml and 1 mg/ml) solution. Cell viability was evaluated using a colorimetric assay MTT: 3-(4,5-dimethyl-thiazolyl-2)-2,5- diphenyltetrazolium bromide) in an experimental time of 24, 48 and 72 h (n = 7). Mineral deposition and quantification provided by the cells was tested using the Alizarin Red staining and Cetylpyridinium Chloride (CPC), respectively, after 30 days (n = 4). Gene expression of Runt-related transcription factor 2 (RUNX2), Alkaline phosphatase (ALP) and Osteocalcin (OCN) was quantified using quantitative polymerase chain reaction (RT-qPCR), at 3 and 7 days with Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as the housekeeping gene, and relative gene expression was measured using the ΔΔCq method. Data were analyzed using Kruskall-Wallis followed by multiple comparisons, and T-test for gene expression with α=0.05. RESULTS: All tested concentrations (10 µg/ml, 100 µg/ml and 1 mg/ml) were not cytotoxic at time 24 and 48 h. After 72 h, a slight decrease in cell viability was observed for the lowest concentration (10 µg/ml). The concentration of 100 µg/ml P11-4 showed the highest mineral deposition. However, qPCR analysis of P11-4 (10 µg/ml) showed upregulation of RUNX2 and OCN at 3 days, with downregulation of ALP at 3 and 7d CONCLUSION: P11-4 did not affect cell viability, induced mineral deposition in SCAPs, and upregulated the expression of RUNX2 and OCN genes at 3 days, while downregulating ALP expression at 3 and 7 days. CLINICAL SIGNIFICANCE: Based on the results obtained in this study it can be stated that self-assembling peptide P11-4 is a potential candidate to induce mineralization on dental stem cells for regenerative purposes and also for a clinical use as a capping agent without compromising the cells health.

TiO2 nanotube-containing glass ionomer cements display reduced aluminum release rates.

Titanium dioxide nanotubes (TiO2-nts) were incorporated into a glass ionomer cement (GIC) with improved mechanical properties and antibacterial activity. The aims of the present in vitro study were to define the elemental characterization, aluminum (Al) release rate, and initial working time for GIC reinforced with TiO2-nts, in an experimental caries model. TiO2-nts were incorporated into GIC powder components at 5% by weight, and compared with unblended GIC. Experimental approaches used energy-dispersive spectrometry (EDS), atomic absorption spectrophotometry (AAS), and brightness loss to define surface element properties, Al release rates, and initial working time, respectively. Statistical analysis was performed by 2-way ANOVA, Tukey's test, generalized linear models, and Student's t test (a = 0.05). EDS data analysis revealed that TiO2-nts incorporated into GIC had no significant impact on the typical elemental composition of GICs in an in vitro caries model. Regarding the demineralizing solution, GIC with TiO2-nt significantly decreased the Al release rate, compared with the control group (p < 0.0001). Moreover, TiO2-nt incorporated into GIC did not alter the initial working time of the material (p > 0.05). These findings add information to our scientific body of knowledge concerning the potential impact of TiO2-nt on the performance of conventional GICs.

Self-assembly peptide P11-4 induces mineralization and cell-migration of odontoblast-like cells.

OBJECTIVES: Self-assembling peptide P11-4 is amphiphilic and pH-triggered, effective on repairing early enamel carious lesions and dentin remineralization. However, P11-4 effects on dentin biomineralization and repair ability remain unexplored. Thus, cytocompatibility and effectiveness of P11-4 on inducing mineralization and migration of odontoblast-like cells (MDPC-23) were investigated. METHODS: MDPC-23 were seeded in contact with P11-4 (0.5 and 1 µg/ml), Dentin Matrix Protein 1 (DMP1 0.5 and 1 µg/ml) or Calcium hydroxide (Ca(OH)2 100 µg/ml) solutions. Cell viability was verified using MTT (n = 6/group). Mineral deposition was tested using Alizarin Red (n = 4/group). Cell migration was assessed by light microscopy (n = 2/group). MTT and Alizarin Red data were compared using Kruskal-Wallis and Mann-Whitney (α=0.01). RESULTS: P11-4 (0.5 and 1 µg/ml) and DMP1 (0.5 and 1 µg/ml) resulted the highest cell viability; Ca(OH)2 presented the lowest. 1 µg/ml DMP1 and 1 µg/ml P11-4 promoted the highest mineral deposition. Ca(OH)2 presented lower values of mineral deposits than DMP1 1 µg/ml (p < 0.01), but similar to P11-4 1 µg/ml. P11-4 and DMP1 at 0.5 µg/ml induced lesser mineral precipitation than P11-4 and DMP1 at 1 µg/ml (p < 0.01), with no difference to Ca(OH)2. All materials stimulated cell migration, however, lower concentrations of DMP1 and P11-4 demonstrated a higher migration potential. CONCLUSION: P11-4 did not affect cell viability, induces mineral deposition and MDPC-23 migration like DMP1. CLINICAL SIGNIFICANCE: Self-assembling peptide P11-4 does not affect the cell viability and induces mineral deposition comparable to native protein involved in biomineralization. Combined with its ability to bind type I collagen, P11-4 is a promising bioinspired molecule that provides native-tissue conditions and foster further studies on its ability to form dentin bridges in pulp-capping strategies.

TiO2 nanotube-containing glass ionomer cements display reduced aluminum release rates

Abstract Titanium dioxide nanotubes (TiO2-nts) were incorporated into a glass ionomer cement (GIC) with improved mechanical properties and antibacterial activity. The aims of the present in vitro study were to define the elemental characterization, aluminum (Al) release rate, and initial working time for GIC reinforced with TiO2-nts, in an experimental caries model. TiO2-nts were incorporated into GIC powder components at 5% by weight, and compared with unblended GIC. Experimental approaches used energy-dispersive spectrometry (EDS), atomic absorption spectrophotometry (AAS), and brightness loss to define surface element properties, Al release rates, and initial working time, respectively. Statistical analysis was performed by 2-way ANOVA, Tukey's test, generalized linear models, and Student's t test (a = 0.05). EDS data analysis revealed that TiO2-nts incorporated into GIC had no significant impact on the typical elemental composition of GICs in an in vitro caries model. Regarding the demineralizing solution, GIC with TiO2-nt significantly decreased the Al release rate, compared with the control group (p < 0.0001). Moreover, TiO2-nt incorporated into GIC did not alter the initial working time of the material (p > 0.05). These findings add information to our scientific body of knowledge concerning the potential impact of TiO2-nt on the performance of conventional GICs.

Bond strength of different orthodontic brackets produced with different materials and fabrication methods / Resistência de união de bráquetes ortodônticos produzidos com diferentes materiais e métodos de fabricação

Objective: The aim of this study was to evaluate the effects of material and processing methods on the bond strength of orthodontic brackets. Material and Methods: Five types of brackets were tested: Conventional metallic (CM), metallic sandblasted (SB), ceramic (C), polycarbonate (PC), and metallic fabricated by melting injection molding (MIM). Shear bond strength (SBS) was conducted to check bond strength of the brackets bonded to bovine teeth (n=10/group), and tensile bond strength (TBS) (20 brackets/group) to check bracket retention to bonding material (n=20/group). Both, SBS and TBS were conducted with 1mm/min crosshead speed in a universal testing machine. Bond strength was calculated in Megapascal (MPa) based on force (N) and bracket area (mm 2). Data normality was verified, and One-way ANOVA was the statistical test with Tukey post-hoc (α=0.05). Results: SB and MIM presented higher SBS compared to C, PC, and CM (p<0.05). SB and MIM also presented significantly higher TBS compared to CM and PC (p<0.05). However, MIM was not different of C for TBS. Conclusion: The type of material and method of fabrication are determinant factors that affect bond strength of orthodontic brackets and melting injection molding (MIM) is a remarkable technology to improve brackets retention during the orthodontic treatment. (AU)

Objetivo: O objetivo deste estudo foi avaliar os efeitos dos materiais e métodos de processamento na resistência de união de bráquetes ortodônticos. Material e Métodos: Cinco tipos de bráquetes foram testados: Convencionais metálicos (CM), metálicos jateados (SB), cerâmico (C), policarbonato (PC), e metálico fabricado por injeção de metal fundido em molde (MIM). A resistência de união ao cisalhamento (SBS) foi conduzida para verificar a resistência de união dos bráquetes aderidos a dentes bonivos (n=10/grupo) e a resistência à tração (TBS) (20 bráquetes/grupo) para verificar a retenção do bráquete ao material adesivo (n=20/grupo). SBS e TBS foram conduzidas com relação carga/velocidade de 1mm/min em uma máquina de ensaios universal. A resistência de união foi calculada em Megapascal (MPa) com base na força (N) pela área do bráquete (mm 2). A normalidade dos dados e a estatística foi realizada utilizando One-way ANOVA e Tukey post-hoc (α=0.05). SB e MIM apresentaram os maiores valores de SBS comparados com C, PC e CM (p<0.05). Resultados: SB e MIM também apresentaram valores significativamente maiores de TBS comparados com CM e PC (p<0.05). Contudo, os valores de TBS para o grupo MIM não foram significativamente diferentes de C. Conclusão: O tipo de material e o método de fabricação são fatores determinantes que afetam a resistência de união de bráquetes ortodônticos e a injeção de metal fundido em molde (MIM) é uma tecnologia relevante para melhorar a retenção dos bráquetes durante o tratamento ortodôntico. (AU)

CHX Stabilizes the Resin/demineralized Dentin Interface.

The aim of this study was to evaluate the effect of 2% chlorhexidine digluconate (CHX) on microtensile bond strength (µTBS) between an adhesive system and under 3 dentin conditions. For that, this study evaluated the adhesive interface at initial, after 6 months and 1 year of storage. Forty-eight human third molars were prepared and randomly divided into 3 groups, according to dentin substrates: sound dentin (Sd), caries-infected dentin (Ci) and caries-affected dentin (Ca). The groups were subdivided into two according to the dentin pre-treatment: application of 2% CHX or without pre-treatment (control). The dentin surfaces were etched with 35% phosphoric acid gel and bonded with Adper Single Bond 2 (3M ESPE) adhesive system according to manufacturer's instructions. Subsequently, the specimens were stored in deionized water at 37°C for 24h, 6 months and 1 year. Two additional teeth were used to analyze the bonding interfaces by SEM. Data was submitted to three-way ANOVA in a split plot design and Tukey's test (α = 0.05). The results showed that Ci decreased µTBS values when compared to Ca and Sd, regardless storages time or treatment. Stored samples for 6 months and 1 year decreased the µTBS for the control group, but no difference was found between storages time for the CHX group. As a conclusion, the 2% CHX application after etching showed improved dentin bond strength in the storage time, regardless of the substrates evaluated.

Correction: Trans,trans-farnesol, an antimicrobial natural compound, improves glass ionomer cement properties.

[This corrects the article DOI: 10.1371/journal.pone.0220718.].

CHX stabilizes the resin/demineralized dentin interface

Abstract The aim of this study was to evaluate the effect of 2% chlorhexidine digluconate (CHX) on microtensile bond strength (µTBS) between an adhesive system and under 3 dentin conditions. For that, this study evaluated the adhesive interface at initial, after 6 months and 1 year of storage. Forty-eight human third molars were prepared and randomly divided into 3 groups, according to dentin substrates: sound dentin (Sd), caries-infected dentin (Ci) and caries-affected dentin (Ca). The groups were subdivided into two according to the dentin pre-treatment: application of 2% CHX or without pre-treatment (control). The dentin surfaces were etched with 35% phosphoric acid gel and bonded with Adper Single Bond 2 (3M ESPE) adhesive system according to manufacturer's instructions. Subsequently, the specimens were stored in deionized water at 37°C for 24h, 6 months and 1 year. Two additional teeth were used to analyze the bonding interfaces by SEM. Data was submitted to three-way ANOVA in a split plot design and Tukey's test (α = 0.05). The results showed that Ci decreased µTBS values when compared to Ca and Sd, regardless storages time or treatment. Stored samples for 6 months and 1 year decreased the µTBS for the control group, but no difference was found between storages time for the CHX group. As a conclusion, the 2% CHX application after etching showed improved dentin bond strength in the storage time, regardless of the substrates evaluated.

Resumo O objetivo deste estudo foi avaliar o efeito do digluconato de clorexidina 2% (CHX) na resistência de união à microtração (µTBS) entre um sistema adesivo e sob 3 condições de dentina. Para tanto, este estudo avaliou a interface adesiva no início, após 6 meses e 1 ano de armazenamento. Quarenta e oito terceiros molares humanos foram preparados e divididos aleatoriamente em 3 grupos, de acordo com os substratos dentinários: dentina hígida (Dh), dentina infectada por cárie (Di) e dentina afetada por cárie (Da). Os grupos foram subdivididos em dois de acordo com o pré-tratamento: aplicação de CHX 2% ou sem pré-tratamento (controle). As superfícies da dentina foram condicionadas com gel de ácido fosfórico a 35%, em seguida, utilizou-se o sistema adesivo Adper Single Bond 2 (3M ESPE) de acordo com as instruções do fabricante. Posteriormente, os corpos-de-prova foram armazenados em água deionizada a 37°C por 24h, 6 meses e 1 ano. Dois dentes adicionais foram usados ​​para analisar as interfaces de união no MEV. Os dados foram submetidos a ANOVA três fatores em esquema de parcela subdividida e ao teste de Tukey (α = 0,05). Os resultados mostram que a Di diminuiu os valores de µTBS quando comparado as Da e Dh, independente do tempo de armazenamento ou tratamento. Amostras armazenadas por 6 meses e 1 ano diminuíram a µTBS para o grupo de controle, mas nenhuma diferença foi encontrada entre o tempo de armazenamento para o grupo CHX. A aplicação de CHX 2% após o condicionamento apresentou melhora na resistência de união à dentina no tempo de armazenamento, independente dos substratos avaliados.

Titanium dioxide nanotubes added to glass ionomer cements affect S. mutans viability and mechanisms of virulence.

This in vitro study evaluated the impact of TiO2 nanotubes (n-TiO2) incorporated into glass ionomer cement (GIC) on Streptococcus mutans (S. mutans) characteristics at cellular and molecular levels. n-TiO2, synthesized by the alkaline method (20 nm in size), was added to Ketac Molar EasyMix® at 0%, 3%, 5%, and 7% by weight. S. mutans strains were cultured on GIC disks with addition or not of n-TiO2 for 1, 3, and 7 days and the following parameters were assessed: inhibition halo (mm) (n=3/group); cell viability (live/dead) (n=5/group); cell morphology (SEM) (n=3/group); and gene expression by real-time PCR (vicR, covR, gtfB, gtfC, and gtfD) (n=6/group). The data were analyzed by the Kruskal-Wallis test, repeated-measures ANOVA or two-way ANOVA, and Tukey's and Dunn's post-hoc tests (α=0.05). The agar diffusion test showed a higher antibacterial property for 5% n-TiO2 compared with 3% and 7% (p<0.05) with no effect of time (1, 3, and 7 days). The cell number was significantly affected by all n-TiO2 groups, while viability was mostly affected by 3% and 5% n-TiO2, which also affected cell morphology and organization. Real-time PCR demonstrated that n-TiO2 reduced the expression of covR when compared with GIC with no n-TiO2 (p<0.05), with no effect of time, except for 3% n-TiO2 on vicR expression. Within-group and between-group analyses revealed n-TiO2 did not affect mRNA levels of gtfB, gtfC, and gtfD (p>0.05). Incorporation of n-TiO2 at 3% and 5% potentially affected S. mutans viability and the expression of key genes for bacterial survival and growth, improving the anticariogenic properties of GIC.

Analysis of enamel/restoration interface submitted cariogenic challenge and fluoride release.

The treatment of high-risk patients still is a challenge. The understanding and development non-invasive, non-destructive, and non-ionizing techniques, can help to guide the treatment and the diagnosis of primary and recurrent caries. The present study evaluated the behavior of enamel/restoration interface after a cariogenic challenge by Fourier domain optical coherence tomography (FD-OCT), scanning electron microscopy (SEM) examination, and the fluoride release of the different restorative materials. Cavities (1.5 × 0.5 mm) were performed in enamel surface and divided into groups (n = 8): glass ionomer cement (GIC), resin-modified glass ionomer cement (RMGIC), and resin composite (RC). The samples were submitted to pH-cycling, and the solutions analyzed for cumulative fluoride by ion-analyzer. The morphology was analyzed by SEM through replicas. The optical attenuation coefficient (OAC) was calculated through exponential decay from the images generated by FD-OCT. Data were analyzed considering α = 0.05. OAC values increased for all groups after pH-cycling indicating demineralization (p < .05). Considering the remineralizing solution, RMGIC presented higher fluoride release rate, followed by GIC, while RC did not release any fluoride. Yet for the demineralizing solution, RMGIC and GIC released similar fluoride rates, overcoming RC (p < .05). Micrographs revealed no changes on the restorations margins, although enamel detachment was observed for RC and GIC after pH-cycling.

Impact of biomineralization on resin/biomineralized dentin bond longevity in a minimally invasive approach: An "in vitro" 18-month follow-up.

OBJECTIVES: To determine the impact of treating caries-affected dentin (CAD) with: 0.2% sodium fluoride (NaF), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP/MI Paste™) or peptide P11-4 (Curodont™ Repair) on the longevity of resin/CAD interface at storage times of 24 -h, 6- and 18-month. METHODS: 255 caries-free third molars were used, and CAD was produced by a biological method. The teeth were randomly distributed into: G1- Sound dentin (SD); G2- CAD; G3- CAD + 0.2% NaF (CAD/NaF); G4- CAD + CPP-ACP (CAD/ACP); G5- CAD + Curodont™ Repair (CAD/P11-4). The Filtek Z350 composite resin block was bonded to dentin using Adper™ Single 2 (4 mm/height). Resin/dentin blocks were stored in a solution of Simulated Body Fluid at 37 °C, pressures were modified to simulate natural pulpal pressures. Specimens were investigated by microtensile bond strength (µTBS) (n = 8), Scanning Electron Microscopy (to assess the failure mode) (n = 8), nanoinfiltration (to assess the interface sealing) (n = 3), in situ zymography (to assess the gelatinolytic activity) (n = 3) and micro-computed microtomography (µ-CT) (to assess the mineralization) (n = 3). Data from µTBS, µ-CT and, nanoinfiltration and hybrid layer formation/degradation were submitted to two-way ANOVA and Tukey tests, and failure patterns and in situ zymography to Kruskal-Wallis and Dunn tests (α = 5%). RESULTS: The highest mineral density change by µ-CT, smallest silver nitrate infiltration and proteolytic activity in the adhesive layer were obtained significantly for the groups SD, CAD/ACP and CAD/P11-4, with most mixed fractures at 18-month (p < 0.001). CAD/NaF showed significantly similar values to CAD, CAD and CAD/NaF which presented a high percentage of adhesive fracture (p < 0.001) at all time periods. SIGNIFICANCE: Treating caries-affected dentin with remineralizing agents CPP-ACP and Curodont™ Repair, has the potential to be a clinically relevant treatment protocol to increase the longevity of adhesive restorations.

Consensus on glass-ionomer cement thresholds for restorative indications.

OBJECTIVE: The aim of this paper is to present the results of a consensus meeting on the threshold property requirements for the clinical use of conventional glass-ionomer cements (GICs) for restorative indications. METHODS: Twenty-one experts on GICs evaluated the results of tests on mechanical and optical properties of 18 different brands of restorative GICs: Bioglass R [B], Chemfil Rock [CR], Equia Forte [EF], Gold Label 2 [GL2], Gold Label 9 [GL9], Glass Ionomer Cement II [GI], Ionglass [IG], Ion Z [IZ], Ionomaster [IM], Ionofil Plus [IP], Ionostar Plus [IS], Ketac Molar Easymix [KM], Magic Glass [MG], Maxxion R [MA], Riva Self Cure [R], Vidrion R [V], Vitro Fil [VF] and Vitro Molar [VM]. All experiments were carried out by a team of researchers from Brazil and England following strict protocols, under the same laboratory conditions throughout, and maintaining data integrity. RESULTS: There was consensus on: determining as primary properties of the material: compressive strength, microhardness, acid erosion and fluoride release, and as secondary properties: contrast ratio and translucency parameter, in order to rank the materials. Seven brands were below the thresholds for restorative indications: IZ, IM, IG, MA, VF, B and MG. CONCLUSIONS: Based on the primary properties adopted as being essential for restorative indications, the conventional restorative GICs that met the thresholds and could be considered suitable as long-term restorative materials were: EF, GI, GL9, KM, IP, GL2, IS, CR, V, VM and R. A decision-making process to select the best GIC must also include results from clinical trials. CLINICAL SIGNIFICANCE: This study provides a ranking of GICs that could be considered suitable as long-term restorative materials based on their main properties.

Fluoride release and remineralizing potential of varnishes in early caries lesions in primary teeth.

This study evaluated the fluoride (F) release and remineralizing potential of varnishes containing sodium fluoride (5% NaF), 5% NaF with CPP-ACP and 5% NaF with TCP in early caries lesions in primary teeth. To determine the F release at 1, 4, 6, 24, 72, and 168 hr, strips were covered with the varnishes and immersed in purified water (n = 7). The varnishes and purified water (negative control) were applied on enamel blocks with early caries lesions (n = 16). Enamel blocks were stored in artificial saliva and submitted to a pH-cycling. The area of enamel hardness loss (ΔS) was analyzed by microhardness, lesion depth by polarized light microscopy (PLM) and the chemical analysis by Energy-dispersive X-ray spectroscopy. Data were submitted to Shapiro-Wilk, two-way and one-way ANOVA, Tukey and paired t-tests (α = 5%). All varnishes released F, but 5% NaF with CPP-ACP had the highest release at 4, 6, 24, and 72 hr (p < .05) followed by 5% NaF with TCP and 5% NaF. No significant difference in ΔS was observed among varnishes (5% NaF = 4,098.4 ± 1,407.9; 5% NaF with CPP-ACP = 4,164.0 ± 1,019.3; 5% NaF with TCP = 4,183.2 ± 1,527.2; p = .999), but all of them differed from the negative control group (6,757.8 ± 2,274.7; p < .001). Lesion depth was lower in varnishes groups compared to negative control (% reduction: 5% NaF = 41.8%, 5% NaF with CPP-ACP = 38.8%, and 5% NaF with TCP = 36.3%; p < .001). Similar Ca, P, and Ca/P ratio percentages among groups and F was not detected after the treatments. All fluoride varnishes showed potential to enhance remineralization of early caries lesions in primary teeth.

A minimally invasive technique for primary tooth extraction: a case report / Técnica minimamente invasiva para exodontia de dente decíduo: relato de caso

ABSTRACT Root resorption is characterized by the loss of cementum and / or dentin from the tooth root as a result of internal or external odontoclastic action. This case reports a premature cervical root resorption of deciduous teeth in an 8-year-old boy. Large root resorption on the mesial faces of the maxillary and mandibular right and left deciduous canines (teeth #53, #63, #73 and #83), with asymptomatic pulp involvement, was detected during routine radiographic examination for orthodontic planning. The patient was managed with extraction of the affected teeth using two different techniques: conventional and alternative. The conventional technique, forceps, was used for the maxillary and mandibular left canines (teeth #63 and #73). And alternative technique using the periotome device, usually required for extraction during dental implant surgery, was used for the maxillary and mandibular right canines (teeth #53 and #83). The periotome device showed to be an alternative to improve pediatric surgery due to better patient behavior and healing, and to reduced procedure length.

RESUMO A reabsorção radicular é caracterizada pela perda de cemento e/ou dentina da raiz do dente como resultado de uma ação odontoclástica interna ou externa. Este caso relata uma reabsorção cervical precoce da raiz dos dentes decíduos numa criança de 8 anos de idade. Grande reabsorção radicular nas faces mesiais dos caninos decíduos superiores e inferiores direito e esquerdo (dentes #53, #63, #73 e #83), com envolvimento assintomático da polpa, foi detectada durante o exame radiográfico de rotina para planejamento ortodôntico. O paciente foi submetido à exodontia dos dentes comprometidos, utilizando duas técnicas distintas: convencional e alternativa. A técnica convencional, fórceps, foi escolhida para os caninos esquerdo maxilar e mandibular (dentes n.º 63 e n.º 73). E a técnica alternativa utilizando o instrumento periótomo, normalmente necessário para exodontias prévias a cirurgia de implantes dentários, foi utilizada para os caninos direito maxilar e mandibular (dentes n.º 53 e n.º 83). O instrumento periótomo demonstrou ser uma alternativa para melhorar a cirurgia pediátrica devido ao melhor comportamento e cicatrização do paciente, e à redução da duração do procedimento.

Oral rehabilitation in a child with early childhood caries: a case report / Reabilitação oral em criança com cárie na primeira infância: relato de caso

ABSTRACT The aim of the current study is to present a treatment approach in a case of severe early childhood caries (ECC). A 5-year-old girl was referred to the Pediatric Dentistry Division with multiple premature tooth loss, masticatory difficulties, prolonged breast-feeding, and low quality of life, who was diagnosed with severe ECC. A three-phased treatment plan was implemented: 1. Disease control - consisting of behavioral changes in oral hygiene habits, diet guidance, professional biofilm removal followed by fluoride application and temporary restorations; 2. Infection control - teeth extractions and pulpotomy; and 3. Functional rehabilitation - direct and semi-indirect resin restorations, a removable partial and total prostheses in the lower and upper jaws, respectively. In conclusion, the proposed multidisciplinary approach resulted in a positive impact on the patient's nutrition and growth, speech production, communication, self-image, and social functioning leading to an improved quality of life.

RESUMO O objetivo do presente estudo é apresentar uma abordagem de tratamento em um caso de cárie na primeira infância (CPI). Uma menina de 5 anos foi encaminhada à área de Odontopediatria com múltiplas perdas dentárias precoces, dificuldades mastigatórias, amamentação prolongada e baixa qualidade de vida, com diagnóstico de CPI severa. Um plano de tratamento em três fases foi implementado: 1. Controle da doença - consistindo em mudanças comportamentais nos hábitos de higiene bucal, orientação alimentar, remoção profissional do biofilme seguida de aplicação de flúor e restaurações provisórias; 2. Controle de infecção - exodontias e pulpotomia; e 3. Reabilitação funcional - restaurações diretas e semi-indiretas de resina, próteses parcial e total removíveis nos maxilares inferior e superior, respectivamente. Em conclusão, a abordagem multidisciplinar proposta resultou em um impacto positivo na nutrição e crescimento do paciente, produção da fala, comunicação, autoimagem e socialização, levando a uma melhoria da qualidade de vida.

Titanium dioxide nanotubes added to glass ionomer cements affect S. mutans viability and mechanisms of virulence

Abstract This in vitro study evaluated the impact of TiO2 nanotubes (n-TiO2) incorporated into glass ionomer cement (GIC) on Streptococcus mutans (S. mutans) characteristics at cellular and molecular levels. n-TiO2, synthesized by the alkaline method (20 nm in size), was added to Ketac Molar EasyMix® at 0%, 3%, 5%, and 7% by weight. S. mutans strains were cultured on GIC disks with addition or not of n-TiO2 for 1, 3, and 7 days and the following parameters were assessed: inhibition halo (mm) (n=3/group); cell viability (live/dead) (n=5/group); cell morphology (SEM) (n=3/group); and gene expression by real-time PCR (vicR, covR, gtfB, gtfC, and gtfD) (n=6/group). The data were analyzed by the Kruskal-Wallis test, repeated-measures ANOVA or two-way ANOVA, and Tukey's and Dunn's post-hoc tests (α=0.05). The agar diffusion test showed a higher antibacterial property for 5% n-TiO2 compared with 3% and 7% (p<0.05) with no effect of time (1, 3, and 7 days). The cell number was significantly affected by all n-TiO2 groups, while viability was mostly affected by 3% and 5% n-TiO2, which also affected cell morphology and organization. Real-time PCR demonstrated that n-TiO2 reduced the expression of covR when compared with GIC with no n-TiO2 (p<0.05), with no effect of time, except for 3% n-TiO2 on vicR expression. Within-group and between-group analyses revealed n-TiO2 did not affect mRNA levels of gtfB, gtfC, and gtfD (p>0.05). Incorporation of n-TiO2 at 3% and 5% potentially affected S. mutans viability and the expression of key genes for bacterial survival and growth, improving the anticariogenic properties of GIC.