Addition of substances to reduce the erosive potential of acidic beverages to tooth enamel: A scoping review.

OBJECTIVE: This scoping review aimed (1) to map, analyse, interpret and synthesize data from in situ studies on which substances were added to acidic beverages to reduce the erosive potential on tooth enamel and (2) to establish the level of evidence of the effectiveness of adding substances to acidic beverages to reduce the erosive potential on tooth enamel. DESIGN: This is a scoping review, according to the methods from the Joanna Briggs Institute and PRISMA-ScR, with high-sensitivity searches in the databases PubMed (MEDLINE), Virtual Health Library, Embase (Elsevier), Scopus (Elsevier), Web of Science and ScienceDirect (Elsevier). In situ studies published in English until December 2022 were included. Studies that did not report a control group were excluded. To map and summarize the results, tables and figures were used. RESULTS: From 895 potentially eligible articles, nine were included. Blackcurrant juices (n = 5) with the addition of calcium (n = 3) or xanthan gum (n = 2) formulations were the most tested in terms of reducing the erosive potential of the beverages on tooth enamel. The profilometer was the equipment of choice (n = 8) for evaluating the loss of enamel structure after the experimental tests. CONCLUSIONS: Calcium and xanthan gum are among the most tested by in situ studies, offering promising results in reducing the erosive potential of fruit juices and carbonated and energy drinks.

Increase in plasma resveratrol levels and in acid-resistant proteins in the acquired enamel pellicle after use of resveratrol-containing orodispersible tablets.

OBJECTIVE: This study evaluated the effect of administration of trans-resveratrol-containing orodispersible tablets on the protein composition of the AEP and on blood plasma trans-resveratrol concentrations. METHODS: Ten volunteers participated in two crossover double-blind phases. In each phase, after dental prophylaxis, they received a trans-resveratrol (15 mg) orodispersible tablet, or a placebo tablet (without actives). The AEP formed after 120 min was collected with electrode filter papers soaked in 3 % citric acid. Blood samples were collected 30, 45, 60 and 120 min after the use of the tablet. After protein extraction, AEP samples were analyzed by shotgun labelfree quantitative proteomics and plasma samples were analyzed by high-performance liquid chromatography (HPLC). RESULTS: Eight hundred and two proteins were identified in the AEP. Among them, 336 and 213 were unique to the trans-resveratrol and control groups, respectively, while 253 were common to both groups. Proteins with important functions in the AEP had increased expression in the trans-resveratroltreated group, such as neutrophil defensins, S100 protein isoforms, lysozyme C, cystatin-D, mucin-7, alphaamylase, albumin, haptoglobin and statherin. Trans-resveratrol was detected in the plasma at all the times evaluated, with the peak at 30 min. CONCLUSIONS: The administration of trans-resveratrol in sublingual orodispersible tablets was effective both to increase the bioavailability of the polyphenol and the expression of antibacterial and acid-resistant proteins in the AEP, which might benefit oral and general health.

Are S-PRG composites able to resist against erosive and abrasive challenges and protect surrounding enamel in situ?

OBJECTIVES: This study evaluated the resistance of S-PRG (Surface Pre-Reacted Glass-ionomer) composites and other restorative materials against erosive and abrasive challenges and their protective effect on enamel adjacent to the restorations. MATERIALS AND METHODS: Bovine enamel blocks were prepared and randomized into 12 groups, including 6 types of material, each of them subjected to erosion_e or erosion+abrasion_ea: Beautifil II (S-PRG); Beautifil Bulk Restorative (S-PRG); Filtek Z250 XT; Filtek Bulk Fill; EQUIA Forte; Riva Light Cure. Cavities were prepared in the middle of enamel blocks and restored with the materials. Initial profiling measurement was performed on the material and on adjacent enamel (100, 200, 300, 600 and 700 µm from the restoration margin). Palatal intraoral appliances with the restored enamel blocks were used by the volunteers (n = 10). During 5 days appliances were immersed in 2.5 % citric acid for 2 min; 6 × /day (erosion_e). For ea condition, blocks were brushed for 1 min after each acid immersion. Final profile assessment was performed. Data were analysed by two and three way ANOVA followed by Tukey's test (p < 0.05). RESULTS: Material wear: Riva Light Cure showed the highest wear followed by EQUIA Forte and then all resin composites, including the ones with S-PRG (p = 0.000). Enamel wear: there was significant interaction among type of restorative material, wear condition and distance (p = 0.014), enamel around materials showed similar wear (p = 0.983) and the enamel subjected to ea exhibited highest wear (p = 0.000). CONCLUSION: SPRG based composites showed resistance against erosive and abrasive challenges but were not able to protect enamel adjacent to the restorations. CLINICAL SIGNIFICANCE: S-PRG composites exhibit resistance to material wear comparable to resin composites. However, they have shown an inability to effectively protect the adjacent enamel under in situ erosive-abrasive conditions, despite the presence of mineral-loss-preventing ions surrounding materials.

In vitro assessment of dental erosion caused by clear aligners.

The primary objective of this in vitro study was to investigate the erosive potential of enamel under the use of clear aligners (CA), by simulating in vivo conditions experienced by patients who do not remove their CA during the consumption of acidic beverages. In addition, the difference in erosion protection conferred by artificial and human saliva was also evaluated. Sound-extracted human premolars (n = 20) had half of their surfaces protected with acid-resistant nail polish and were randomly distributed into two experimental groups (n = 10): teeth immersed in human saliva or artificial saliva. All teeth had half of their lingual surfaces enclosed by a CA device. The erosive challenges consisted of individual immersion of each sample in citrus acid three times a day, intermediated by immersion in human saliva or artificial saliva for 2 h, during ten days of the erosive protocol. The enamel mineral content was analyzed by high-resolution microtomography. The differential mineral concentration profiles were obtained by subtracting the profile of the mineral concentration of the exposed area and enamel under the CA area from the respective sound area (control). In addition, enamel wear and enamel volume loss were measured. Scanning electron microscopy (SEM) was also performed to analyze the enamel surface. Data were analyzed by two-way ANOVA, followed by the Student-Newman-Keuls test. The enamel wear was higher in teeth immersed in artificial saliva, when compared to human saliva (p < 0.001). The volume loss of the exposed enamel area was lower for tooth immersed in human saliva than in artificial saliva (p < 0.001), during the acid challenge protocol. The use of CA during acid challenges promoted wear and mineral loss of dental enamel, being these changes more pronounced on the enamel surface under the CA. These results open a new path for the development of further studies adopting clinical protocols that promote more accurate responses in the clinical practice during orthodontic treatment.

Erosive tooth wear among non-institutionalised older adults in Hong Kong: a cross-sectional study.

BACKGROUND: Non-institutionalised older adults is the majority of older adults in Hong Kong. The study aimed to examine erosive tooth wear (ETW) and its association with dental conditions and oral hygiene habits among non-institutionalised older adults in Hong Kong. METHODS: This cross-sectional study recruited dentate adults aged 60 or above from nine elderly daycare centres in the five main districts of Hong Kong. The study consists of a questionnaire survey and a clinical examination. A researcher used a questionnaire to collected the participants' demographic information, oral hygiene habits such as toothbrushing habits and dental visit behaviour. A calibrated examiner performed an oral examination in the daycare elderly centre to assess the ETW using basic erosive wear (BEWE) criteria. Oral hygiene was recorded using visible plaque index. Prosthetic status was recorded using the World Health Organization criteria. Logistic regression was used to examine the correlation between ETW and the dental conditions and oral hygiene habits. RESULTS: This study recruited 433 dentate adults and 333 adults were female (77%). Their age ranged from 60 to 99 years and their mean age was 74 years (SD = 7). They all had ETW (BEWE > 0). Over half of them (57%) had BEWE score of 3, indicating severe ETW. Analysis showed increasing age (OR = 1.030, p = 0.029) and older adults with untreated dental caries had higher odds (OR = 1.822, p = 0.002) of presenting severe ETW. No other associations were found between the ETW and the factors studied. CONCLUSION: Hong Kong non-institutionalised older adults aged 60 or above had ETW and more than half of them had severe ETW. Increasing age and having untreated dental caries were associated with severe ETW.

Novel resin-based material containing ß-tricalcium phosphate nanoparticles for the reduction of dentin permeability.

OBJECTIVES: To synthesize and characterize a novel dentin adhesive containing Beta-Tricalcium Phosphate (ß-TCP) nanoparticles and test its ability to reduce dentin permeability (dP). METHODS: Experimental adhesives were prepared by mixing Bis-GMA, TEGDMA, HEMA (50/25/25 wt.%), photo-initiators, and inhibitors. The following groups were tested: Experimental adhesives without ß-TCP (Exp.); with 10 wt.% ß-TCP (Exp.10 wt.% ß-TCP); with 15 wt.% ß-TCP (Exp.15 wt.% ß-TCP), Scotchbond Multi-Purpose (SBMP) and Clearfil SE Protect Bond (CFPB). Degree of conversion (DC%, 10 and 20 s); Flexural Strength (FS), Knoop Hardness (KHN), and Cell Viability (OD%) tests were performed. dP was evaluated by hydraulic conductance, using human dentin disks (n=12), at three-time intervals: post-EDTA (T0); post-treatment (T1); and post-erosion/abrasion cycling (T2). Data were statistically analyzed (α=0.05). RESULTS: For all groups, exposure time for 20 s presented a higher DC% than for 10 s. For FS, filled adhesives did not differ from unfilled and from CFPB. Experimental adhesives did not differ among them and showed lower KHN than the commercial products. Cell viability did not differ among adhesives, except Exp. 15 wt.%, which showed lower OD% than Exp., Exp. 10% and, CFPB. For dP, only Exp.10 and 15 wt.% ß-TCP did not present difference between the times T1 and T2. After cycling, Exp.10 wt.% ß-TCP presented lower permeability than Exp. and CFPB. CONCLUSIONS: The incorporation of 10 wt.% ß-TCP nanoparticles into the resin-based dental material did not affect its mechanical properties and biocompatibility, and promoted the greatest reduction in dentin permeability, sustaining this effect under erosive/abrasive challenges. CLINICAL SIGNIFICANCE: A novel resin-based dental material containing ß-TCP nanoparticles was able to reduce dentin permeability, maintaining its efficacy after erosive/abrasive challenges. The synthesized material did not affect dental pulp cell viability and might be promising for other conditions that require dental remineralization, such as tooth wear and dental caries.

Efeito protetor de dentifrícios fluoretados associados ao polímero aminometacrilato no desgaste erosivo do esmalte / Protective effect of fluoride dentifrices in association with aminomethacrylate polymer against the enamel erosive wear

O desgaste dental erosivo tem se tornado uma condição cada vez mais preocupante, com taxas globais de prevalência crescentes, principalmente em indivíduos jovens. Os polímeros formadores de filme têm sido investigados como uma alternativa para o controle da progressão do desgaste dental erosivo, especialmente quando associados a compostos fluoretados, protegendo o tecido dental contra a ação dos ácidos. Dentre eles está o aminometacrilato, que mostrou resultados promissores em estudos prévios sob a forma de solução, porém seu efeito quando adicionado a formulações de dentifrícios ainda não havia sido pesquisado. Dessa forma, o presente estudo visou avaliar o potencial protetor da associação do aminometacrilato com dentifrícios fluoretados frente à erosão inicial e ao desgaste erosivo do esmalte. Para isso, 72 espécimes em esmalte bovino polido foram alocados aleatoriamente em seis níveis de tratamento: erosão (controle negativo sem desafio abrasivo- CNE), abrasão sem dentifrício (controle negativo da abrasão- CNA), dentifrício sem agente ativo (placeboPL), dentifrício com fluoreto de sódio (NaF ­ 1450 ppm F-), dentifrício experimental com aminometacrilato (AMC ­ 4%) e dentifrício fluoretado com aminometacrilato (AMC+F). O grupo CNE foi submetido apenas à ciclagem erosiva, e os demais passaram por desafios erosivos e abrasivos. A ciclagem erosiva/abrasiva consistiu em imersão dos espécimes em saliva humana (1h) para a formação da película adquirida, exposição ao ácido cítrico 0,3% por 5 minutos (4x/dia) e aplicação dos tratamentos (2x/dia), intercalados por imersão em saliva humana (1h), todos sob agitação (30 rpm). A ciclagem foi repetida por 5 dias. A microdureza superficial Knoop (KN) dos espécimes foi analisada no primeiro dia da ciclagem para avaliação da erosão inicial do esmalte. A análise foi realizada em quatro momentos: KNinicial (esmalte sadio), KNE1(após a primeira exposição ao ácido), KNT (após o tratamento), KNE2 (após a segunda exposição ao ácido). Com base nestes valores, foram calculados o potencial de reendurecimento (%Re = [(KNT-KNE1) / (KNE1)] x 100) e de proteção do esmalte (%Prot = [(KNE2-KNE1) / (KNE1)] × 100). A análise perfilométrica foi realizada antes e depois do término da ciclagem (após 5 dias) para determinação da perda de estrutura (em µm). O potencial de adsorção de flúor solúvel em KOH no esmalte foi analisado ao final do ciclo erosivo (µg/cm2). Espécimes representativos de cada grupo foram observados em microscopia eletrônica de varredura após o término da ciclagem. Foram aplicados os testes ANOVA um fator e Tukey (5%). Os valores para %Re foram: CNE (3,11±4,09)a; CNA (1,62±11,38)a; PL (1,78±3,51)a; AMC (5,59±3,08)a; F (7,53±9,17)a; AMC+F (20,23±7,10)b. Para %Prot foram: CNE (-50,68±5,27)a; CNA (-49,71±6,43)a; PL (-51,65±3,74)a AMC (-41,21±8,47)b; F (-34,10±5,99)b; AMC+F (-19,80±7,95)c. Para perda estrutural: CNE (7,46±2,26)a, CNA (10,14±2,08)ab, PL(13,11±2,69)c, AMC (7,74±2,10)a, F (11,38±2,07)bc, AMC+F (7,52±2,59)a. Para flúor adsorvido na superfície foram observados os valores de: CNE (0,160 ±0,069)a; CNA (0,179 ±0,034)a; PL (0,275 ±0,142)a; AMC (0,422 ±0,161)a; F (1,29 ±0,311)b; AMC+F (1,46 ±0,217)b. Concluiu-se que a adição do copolímero aminometacrilato em dentifrícios potencializou o efeito do fluoreto de sódio contra a erosão inicial do esmalte e o desgaste erosivo do esmalte (AU)

The erosive tooth wear (ETW) has been a cause of concern, because its prevalence rates have increased in the recent years, mainly in young individuals. Film-forming polymers have been investigated as an alternative to control erosive tooth wear (ETW) progression, notably when associated to fluoride compounds, protecting the dental tissues against acids. Among them, the aminomethacrylate polymer has shown promissing results in previous studies. Nevertheless, its performance when added to toothpaste formulations remains unknown. Therefore, this study aims to evaluate the protective potential of fluoride toothpastes associated with aminomethacrylate against the initial erosion and erosive wear in enamel. For this, 72 polished bovine enamel specimens were divided in six treatments: ultra-pure water (erosion negative control without abrasive challenge- ENC), ultra-pure water (abrasion negative control abrasion without toothpaste- ANC), toothpaste without active agent (placebo- PL), experimental toothpaste with aminomethacrylate (AMC- 4% - AMC), toothpaste with sodium fluoride (NaF- 1450 ppm F- - F), and experimental toothpaste with sodium fluoride + aminomethacrylate (NaF+AMC ­ AMC+F). The NC group was subjected to erosion only. The other groups were subjected to erosion + abrasion. Three response variables were analyzed: initial erosion with Knoop surface microhardness (KN) in the first day of the cycle; enamel loss with profilometric analysis (µm), and surface adsorbed fluoride concentration at the end of the cycle. The erosive/abrasive cycling consisted in immersion of the specimens in human saliva (1 h) to form the acquired pellicle, exposure to citric acid (0.3%) for 5 minutes (4x/day) and treatments application under abrasion (2x/day), with immersion in saliva in the intermediate periods (1 h), all the immersions were realized under constant agitation (30 rpm). This cycling was repeated for 5 days. The microhardness was assessed in four moments: KNinitial (sound enamel), KNE1 (after the first acid exposure), KNT (after the treatment), KNE2 (after the second acid exposure). With these values it was calculated rehardening potential (%Re =[(KNT-KNE1) / (KNE1)] x 100), and protective potential (%Prot = [(KNE2-KNE1) / (KNE1)]100). The profilometric analysis was performed before the first cycle and after the last cycle. Then, the difference between the initial and final profiles were calculated to the enamel loss. Representative specimens from each group were analyzed by scanning electron microscopy (SEM). The data was analyzed by One-Way ANOVA and Tukey Test (5%). The values regarding %Re were: ENC (3,11±4,09)a; ANC(1,62±11,38)a; PL (1,78±3,51)a; AMC (5,59±3,08)a; F (7,53±9,17)a; AMC+F(20,23±7,10)b. For %Prot were observed the values: ENC (-50,68±5,27)a; ANC (-49,71±6,43)a; PL (-51,65±3,74)a; AMC (-41,21±8,47)b; F (-34,10±5,99)b; AMC+F (-19,80±7,95)c. Enamel loss were reported by the following values: ENC (7,46±2,26)a,ANC (10,14±2,08)ab, PL (13,11±2,69)c, AMC (7,74±2,10)a, F (11,38±2,07)bc, AMC+F(7,52±2,59)a. Surface adsorbed fluoride concentration was assessed, and thefollowing values were found: ENC (0,160 ±0,069)a; ANC (0,179 ±0,034)a; PL (0,275±0,142)a; AMC (0,422 ±0,161)a; F (1,29 ±0,311)b; AMC+F (1,46 ±0,217)b. It wasconcluded that the addition of aminomethacrylate copolymer to toothpaste enhancesthe effect of sodium fluoride against initial enamel erosion and erosive wear(AU)

Efeito protetor de enxaguatórios com diferentes fluoretos utilizados previamente aos desafios erosivos/abrasivos em esmalte e dentina / Protective effect of solutions with different fluorides used previously to erosive/abrasive challenges in enamel and dentin

Aim: To evaluate the protection offered by commercial mouthwashes containing sodium fluoride or stannous chloride associated with sodium fluoride to enamel and dentin, prior to erosive and abrasive cycling. Materials and Methods: Enamel and dentin samples were obtained from bovine incisors and subdivided into 3 groups (n=10), according to the fluoridated ingredient tested: FS (sodium fluoride - NaF (225 ppm)); FE (tin fluoride - NaF + SnCl2 (800 ppm Sn2+)); control (distilled water). The samples were submitted to an erosive/abrasive cycle with immersion in citric acid (lemon soda for 5 min, 4×/day, 5 days, with remineralization intervals in artificial saliva for 60 min). Abrasion was carried out with an electric brush (200 g/force) after the first and last cycles, 2x/day, and immediately afterward immersed in the tested solutions. Structure loss was obtained by optical profilometry. The data were subjected to analysis of variance and multiple comparison for each substrate separately. Results: For enamel there was a difference between the groups (p = 0.027), with the FS showing less loss of structure compared to the control 2.02 (±0.48). The FE group showed similar loss to the control and FS 2.32 (±0.58)ab. For dentin there was a difference between the groups (p = 0.011), with FE showing less loss of structure compared to the other groups, 0.82 (25% - 0.34; 75% - 0.95). Discussion: The protection of fluorides in erosive/abrasive challenges depends on the type and dental substrate. Conclusion: Mouthwash with sodium fluoride prior to erosive/abrasive challenges caused less loss of enamel surface, while for dentin, sodium fluoride associated with stannous chloride caused less loss of structure.

Objetivo: Avaliar a proteção oferecida por soluções para bochecho de fluoreto de sódio ou cloreto de estanho associado ao fluoreto de sódio ao esmalte e à dentina, previamente à ciclagem erosiva e abrasiva. Materiais e Métodos: Amostras de esmalte e dentina foram obtidas a partir de incisivos bovinos e subdivididas em 3 grupos (n=10), de acordo com o princípio ativo fluoretado testado: FS (fluoreto de sódio - NaF (225 ppm)); FE (fluoreto de estanho - NaF + SnCl2 (800 ppm Sn2+)); controle (água destilada). As amostras foram submetidas a um ciclo erosivo/abrasivo com imersão em ácido cítrico (refrigerante de limão por 5 min, 4×/dia, 5 dias, com intervalos de remineralização em saliva artificial por 60 min). A abrasão foi realizada com escova elétrica (200 g/força) após o primeiro e o último ciclos, 2×/dia, e logo em seguida imersos nas soluções testadas. A perda de estrutura foi obtida por perfilometria óptica. Os dados foram submetidos à análise de variância e comparação múltipla para cada substrato separadamente. Resultados: Para esmalte houve diferença entre os grupos (p = 0,027), tendo o FS apresentados menor perda de estrutura comparado ao controle 2,02 (±0,48). O grupo FE apresentou perda similar ao controle e ao FS 2,32 (±0,58)ab. Para dentina houve diferença entre os grupos (p = 0,011), sendo que o FE apresentou menor perda de estrutura comparado aos demais grupos 0,82 (25% - 0,34; 75% - 0,95). Discussão: A proteção dos fluoretos em desafios erosivos/abrasivos depende do tipo e do substrato dental. Conclusão: O bochecho com fluoreto de sódio previamente aos desafios erosivos/abrasivos apresentou menor perda de superfície em esmalte, enquanto para dentina o fluoreto de sódio associado ao cloreto de estanho apresentou menor perda de estrutura.

Oral Health and Behavior Patterns of Women with Eating Disorders-A Clinical Pilot Study.

BACKGROUND: Chronic stomach regurgitation associated with eating disorders (EDs) poses a high risk for tooth erosion. This study investigated oral health conditions, behavioral patterns, and tooth erosion in women with EDs. METHODS: 16 ED and 13 healthy women were enrolled; 14 ED and 10 healthy control subjects completed the study. Subjects completed demographic, medical, oral, and behavioral health history questionnaires. Dental caries status was recorded as Decayed, Missing and Filled Teeth (DMFT)index and the severity of tooth erosion as Basic Erosive Wear Examination (BEWE) scores. Saliva was collected for flow rate, pH, and buffering capacity analysis. RESULTS: The ED group had a lower stimulated saliva flow rate and higher DMFT index but no significant difference in BEWE scores compared to the controls (t-test, significance level 0.05). Five of the fourteen ED subjects exhibited extensive tooth erosion, which may have been exacerbated by their tooth-brushing behavior. CONCLUSIONS: Although some ED subjects showed extensive tooth erosion in this pilot study, the average BEWE score of the ED group was not significantly different from the controls. Extensive tooth erosion in ED may relate to the low stimulated salivary flow. A larger-scale clinical study is necessary to validate these results.

Advances in Preventive and Therapeutic Approaches for Dental Erosion: A Systematic Review.

This review discusses both preventive measures and clinically implemented therapy procedures that have been developed recently for the prevention and treatment of tooth erosion. METHODS: The databases PubMed, Scopus, and Web of Science were used for a thorough search. Studies on the prevention and treatment of dental erosion that were conducted in English and used in vitro were among the inclusion criteria. RESULTS: The search turned up 391 papers in total, with 34 of those publications matching the requirements for inclusion. Varnishes, toothpastes, and solutions containing fluoride and other substances were used as preventive measures. CONCLUSIONS: Dental erosion is a significant issue, and taking preventative steps is crucial to lessening the disease's spread and its effects. Interventions based on fluoride seem to be successful at halting erosion and encouraging remineralization. To effectively address severe tooth erosion, therapeutic methods, including composite restorations, prosthetic crowns, and veneers, are available. Dental erosion causes aesthetic and functional issues that are best addressed with less invasive treatments like direct composite restorations. To improve and broaden the range of available treatments for this common dental issue, additional research and development are required.

The activity, distribution, and colocalization of cathepsin K and matrix metalloproteases in intact and eroded dentin.

OBJECTIVES: This study aimed to assess the activity, distribution, and colocalization of cathepsin K (catK) and matrix metalloproteases (MMPs) in both intact and eroded dentin in vitro. MATERIALS AND METHODS: Eroded dentin was obtained by consecutive treatment with 5% citric acid (pH = 2.3) for 7 days, while intact dentin remained untreated. Pulverized dentin powder (1.0 g) was extracted from both intact and eroded dentin using 5 mL of 50 mM Tris-HCl buffer (0.2 g/1 mL, pH = 7.4) for 60 h to measure the activity of catK and MMPs spectrofluorometrically. In addition, three 200-µm-thick dentin slices were prepared from intact and eroded dentin for double-labeling immunofluorescence to evaluate the distribution and colocalization of catK and MMPs (MMP-2 and MMP-9). The distribution and colocalization of enzymes were analyzed using inverted confocal laser scanning microscopy (CLSM), with colocalization rates quantified using Leica Application Suite Advanced Fluorescent (LAS AF) software. One-way analysis of variance (ANOVA) was used to analyze the fluorescence data related to enzyme activity (α = 0.05). RESULTS: The activity of catK and MMPs was significantly increased in eroded dentin compared with intact dentin. After erosive attacks, catK, MMP-2, and MMP-9 were prominently localized in the eroded regions. The colocalization rates of catK with MMP-2 and MMP-9 were 13- and 26-fold higher in eroded dentin, respectively, than in intact dentin. CONCLUSIONS: Erosive attacks amplified the activity of catK and MMPs in dentin while also altering their distribution patterns. Colocalization between catK and MMPs increased following erosive attacks. CLINICAL RELEVANCE: CatK, MMP-2, and MMP-9 likely play synergistic roles in the pathophysiology of dentin erosion.

How to optimize bonding procedures on healthy and hypomineralized enamel in orthodontics? / Comment optimiser les procédures de collage sur l'émail sain et hypominéralisé en orthodontie ?

Introduction: Bonding to enamel is a daily problem for the orthodontist. While bonding to healthy enamel is nowadays well mastered, bonding to hypomineralized enamel is much less so. The aim of this article was to help the orthodontist to optimise bonding, whatever the clinical situation. Material and Method: Based on data from the literature, the clinical and microscopic characteristics of healthy and hypomineralised enamel, including amelogenesis imperfecta (AI), molar incisor hypomineralization (MIH), fluorosis or erosion will be described. Proposals for optimising bonding will then be identified and summarized. Results: Bonding to enamel is reliable, but the use of an etch-and-rinse mode (even with a universal adhesive) is recommended. For AI, MIH and fluorosis, the use of sodium hypochlorite after etching seems to significantly increase bonding. No treatment is needed for eroded enamel. However, deep resin infiltration for severe MIH or superficial resin infiltration for fluorosis would reduce the risk of enamel fracture during bracket removal. Conclusion: It is important to be aware of the characteristics of the dental substrate and the materials used to optimize procedures.

Introduction: L'adhésion à l'émail est une problématique quotidienne de l'orthodontiste. Si le collage à l'émail sain est aujourd'hui maîtrisé, celui sur l'émail hypominéralisé l'est beaucoup moins. L'objectif de cet article était d'aider l'orthodontiste à optimiser son collage, quelle que soit la situation clinique. Matériel et méthode: À partir des données issues de la littérature, les caractéristiques clinique et microscopique de l'émail sain et de l'émail hypominéralisé en cas d'amélogenèse imparfaite (AI), d'hypominéralisation de molaire incisive (MIH), de fluorose ou d'érosion seront décrites. Puis, les propositions d'optimisation du collage seront recensées et synthétisées. Résultats: Le collage à l'émail est fiable, mais l'utilisation d'un mode mordançage-rinçage (même avec un adhésif universel) est conseillée. Pour l'AI, la MIH et la fluorose, l'utilisation d'hypochlorite de sodium après mordançage semble significativement augmenter l'adhérence. Aucun traitement n'est nécessaire pour l'émail érodé. Cela dit, une infiltration de résine en profondeur pour les MIH sévères ou superficielles pour la fluorose permettrait de réduire le risque de fracture d'émail à la dépose de l'attache. Conclusion: Il convient de connaître les caractéristiques du substrat sur lequel on colle et celles des matériaux utilisés pour optimiser ses procédures.

Erosive potential of vitamin waters, herbal drinks, carbonated soft drinks, and fruit juices on human teeth: An in vitro investigation.

Background: Dental erosion is the loss of dental hard tissues through the acid dissolution of tooth minerals. One of the major factors that cause erosion is the consumption of acidic food and drinks. This study investigated and compared the effect of vitamin waters, herbal beverages, carbonated soft drinks, and fruit juices on the loss of human dental hard tissue. Methods: Human tooth samples were immersed in various drinks: vitamin waters, herbal beverages, carbonated soft drinks, and fruit juices. The pH value of each drink was measured using a pH meter. The weight of each sample was determined before and after six days of immersion in the tested drink, and the weight loss percentage was calculated. The exposed tooth surfaces were also examined under a scanning electron microscope. Results: Most of the tested drinks were acidic and displayed pH values lower than the critical pH for enamel erosion. Significant weight loss of the tooth samples was found in all tested drink groups. Additionally, the samples immersed in fruit juices and herbal beverages exhibited significantly greater weight loss than those immersed in carbonated soft drinks. Scanning electron micrographs showed samples immersed in the tested drinks to demonstrate structural disintegration with occasional void spaces, except for samples immersed in Doi Kham® Lemongrass drink. Conclusion: Most of the tested drinks have the potential to cause dissolution and destruction of dental hard tissues. Consumers should be aware that prolonged exposure to these drinks could lead to permanent loss of tooth mineral and dental erosion.

Proteomic analysis of stimulated saliva in gastroesophageal reflux disease patients with and without erosive tooth wear: Observational study.

OBJECTIVE: To evaluate the difference in the proteomic profile of stimulated saliva in patients with gastroesophageal reflux disease (GERD) with (GE) and without (GNE) erosive tooth wear (ETW), regarding both human and bacterial proteins. METHODS: Stimulated saliva (SS) was collected from 16 patients (8/group). Samples were centrifuged at 4.500 g for 15 min under refrigeration to remove all debris. The supernatant from each saliva sample was taken and frozen at -80 °C. After extracting the proteins, they were submitted to reverse phase liquid chromatography and mass spectrometry (nLC-ESI-MS/MS). Label-free proteomic quantification was performed using Protein Lynx Global Service (PLGS) software (p < 0.05) for human and bacterial proteins. RESULTS: In total, 67 human proteins were common for GNE and GE groups. GNE group presented, compared to GE group, increase in proteins that confer antimicrobial and acid resistant properties, such as cystatins, histatin and immunoglobulins. However, GNE group had a marked decrease in subunits of hemoglobin (α, ß and delta). Regarding bacterial proteins, for SS, 7 and 10 unique proteins were identified in the GE and GNE groups, respectively. They are related to protein synthesis and energy metabolism and interact with human proteins typically found in saliva and supramolecular complexes of the acquired pellicle. CONCLUSIONS: Our data indicate that the stimulation of the salivary flow increases acid resistant and antimicrobial proteins in saliva, which might protect against ETW. CLINICAL SIGNIFICANCE: This pioneer study showed important differences in the human and bacterial proteome of SS in patients with GERD with or without ETW.

Does the application of dimethyl sulfoxide improve resin bonding to eroded dentine? Four-year in vitro evaluation.

OBJECTIVE: To evaluate the effect of dimethyl sulfoxide (DMSO) on the microtensile bond strength (µTBS) and nanoleakage (NL) of universal adhesives on eroded dentine, immediately and after four years of water storage. METHODS: Sixty-four sound human molars were distributed into 16 groups according to (1) Dentine surface (sound and eroded dentine); (2) dimethyl sulfoxide application (with or without); (3) Application mode (etch-and-rinse or self-etch) and (4) Storage time (immediate and four years). One mild universal adhesive was used (Scotchbond Universal). The restoration was then performed with a composite resin and the specimens were sectioned into resin-dentine bonded sticks. Resin-dentine bonded sticks were tested (immediately and after four years of water storage) for µTBS (0.5 mm/min) or used to assess NL. Data on µTBS and NL were analyzed using four-way ANOVA and Tukey's test (α = 0.05). RESULTS: Only the 3-way cross-product interaction 'substrate vs DMSO vs time' was statistically significant (p = 0.007). Eroded dentine showed a lower mean of µTBS and a higher mean of NL values than sound dentine. However, when DMSO was applied, no significant decrease of µTBS or NL values was observed after four years of water storage, regardless of adhesive strategies, or dentine evaluated, when compared to immediate results. SIGNIFICANCE: Water-based DMSO pre-treatments not only prevent degradation of MDP-containing simplified adhesives but also serve as a potential alternative to improve long-term bonding properties to eroded dentine. The versatility of using a single pre-treatment for both self-etch or etch-and-rinse bonding to eroded dentin may facilitate future clinical applications.

Biomodification of eroded and abraded dentin with epigallocatechin-3-gallate (EGCG).

This study aimed to evaluate in vitro the effects of epigallocatechin-3-gallate (EGCG) as a biomodifier of eroded and abraded dentin. Forty dentin specimens were obtained from the buccal surface of bovine teeth. The specimens were randomly distributed in 4 groups according to dentin substrate: sound or eroded/abraded and dentin biomodification: with 0.5% EGCG and no biomodification (control group). Specimens were subdivided according to aging time: 24 h and 3 months for the analysis of microtensile bond strength (n = 10), morphology of the adhesive interface by SEM (n = 3) and dentin micropermeability by fluorescence microscope (n = 8). Statistical analysis was performed using SPSS system version 20.0 with a significance level of 5%. The results revealed that the control group with eroded-abraded dentin exhibited the lowest bond strength values at 24 h and 3 months. However, the application of 0.5% EGCG as a biomodifier significantly increased bond strength on both sound and eroded-abraded substrates. After 3 months, all groups exhibited an adhesive interface with a more intense fluorescence in the adhesive layer, indicating an increase in porosity at the interface. In conclusion, the EGCG application as a biomodifier enhanced bond strength on both sound and eroded-abraded dentin substrates, however, adhesive interfaces are more regular when restorations are performed on sound dentin, regardless of the biomodification with EGCG.

Eating Disorders and Dental Erosion: A Systematic Review.

Both eating disorders and dental erosion are increasingly affecting adolescents and young adults. Thus, our systematic review was designed to answer the question: "Is there a relationship between dental erosion and eating disorders?" Following the inclusion and exclusion criteria, 31 studies were included in this systematic review (according to the PRISMA statement guidelines). Based on the meta-analysis, 54.4% of patients with bulimia nervosa and 26.7% with anorexia nervosa experienced tooth erosion. For the whole group of 1699 patients with eating disorders, erosive lesions were observed in 42.1% of patients. Bulimics were more than 10 times more likely to experience dental erosion compared to healthy individuals (OR = 10.383 [95%CI: 4.882-22.086]). Similarly, more than 16 times increased odds of tooth erosion were found in patients with self-induced vomiting (OR = 16.176 [95%CI: 1.438-181.918]). In conclusion, eating disorders are associated with an increased risk of developing erosive lesions, especially in patients with bulimia nervosa.

Description of a new laboratory evaluation method of interdental brush abrasion as a clinical hazard.

OBJECTIVES: To simulate the abrasive potential of an interdental brush when applied with toothpastes and prophylactic gels/solutions in a novel laboratory brushing simulation set-up. METHODS: A brushing device was customized to treat dentin samples mimicking a simplified interdental space with an interdental brush (ISO 2). The brushing, that is, 7200 strokes for 1 h, was performed with artificial saliva (control), a povidone-iodine solution, and slurries of chlorhexidine and fluoride gels as well as three toothpastes with different RDA values ranging from 29 to 100, respectively. The loss of dentin was profilometrically assessed and compared with ANOVA and Fishers LSD. RESULTS: While artificial saliva as control, the solution and the gel slurries showed no measurable dentin loss, toothpastes resulted in a measurable linear surface damage with respect to the actual intrinsic RDA values and ranged from 12.6 to 26.5 µm (p < 0.001). CONCLUSIONS: Any interdental cleaning product should be tailored and carefully instructed. Any over- and misuse should be avoided, which applies especially to the use of interdental brushes in combination with abrasive toothpastes.

Association between salivary characteristics and tooth wear: A systematic review and meta-analysis.

OBJECTIVE: Literature was systematically reviewed to identify salivary characteristics and their association with tooth wear. DATA: A protocol was developed a priori (PROSPERO CRD42022338590). Established systematic review methods were used for screening, data extraction, and synthesis. Risk of bias and the certainty of evidence were assessed using the JBI tools and GRADE, respectively. Direct and indirect association between tooth wear and salivary components and characteristics were assessed. SOURCES: MEDLINE, Embase, SCOPUS, Web of Science, CINAHL, and additional sources were searched. STUDY SELECTION: Studies reporting salivary characteristics in patients with tooth wear or models thereof were included. Animal and in-vitro studies and case reports were excluded. RESULTS: One-hundred eleven studies were included. Qualitative analyses showed a negative association between tooth wear and salivary pH and flow rate in many studies. The higher the study size the higher the chances that an association with pH and flow rate was found. Xerostomia, buffer capacity and salivary consistency/viscosity had also some degree of association with tooth wear in fewer studies. Associations with the 39 salivary components were scarcer. Random effects meta-analyses (7 studies) showed that pH levels in stimulated whole saliva were lower in patient with tooth wear compared to controls (-0.07 [-0.10 to -0.04]). However, there was not enough evidence to establish a quantitative association with flow rate. The general risk of bias was unclear and the certainty of evidence was low or very low. A large diversity of methodologies limited the inclusion of all studies in quantitative synthesis. CONCLUSION: From all potential risk factors, stimulated whole saliva pH showed a negative association, both quantitatively and qualitatively with tooth wear, indicating potential usefulness of pH monitoring in these patients. Moreover, associations between flow rate and tooth wear were observed qualitatively. However, in both cases the risk of bias was mostly unclear, and the certainty of evidence was low. No causal associations could be observed. CLINICAL SIGNIFICANCE: Tooth wear is a prevalent condition that may lead to functional or esthetic impairments and pain. Knowing the potential risk factors like salivary pH or flow rate and their dynamics could be relevant during tooth wear monitoring and to intervene accordingly, especially in conditions like gastroesophageal reflux disease.

Fluoride varnishes supplemented with nano-sized sodium trimetaphosphate reduce enamel erosive wear in vitro.

OBJECTIVE: To evaluate the effect of fluoride (F) varnishes with sodium trimetaphosphate (TMP) on erosive tooth wear (ETW) in vitro. METHODS: Enamel blocks (n = 100) were divided into 5 experimental groups (n = 20/group): Placebo (Pla - without F/TMP); 5 % NaF (NaF); 5 % NaF + 5 % micrometric TMP (NaF+5 %MICRO); 5 % NaF + 2.5 % nano-sized TMP (NaF+2.5 %NANO), and 5 % NaF + 5 % nano-sized TMP (NaF+5 %NANO). Blocks received a single varnish application (6 h contact), and were submitted to 4 daily erosive challenges (ERO, 0.05 M citric acid, pH 3.2, 90 s, under agitation), for 5 days. After ERO, half of the blocks (n = 10/group) were subjected to brushing abrasion (ERO+ABR). Profilometry, surface hardness (SH), and cross-sectional hardness (ΔKHN) were determined. The data were submitted to 2-way ANOVA and Fisher's LSD test (p < 0.05). RESULTS: Enamel wear was significantly lower for ERO compared with ERO+ABR for all varnishes tested (p < 0.001), following the pattern NaF+5 %NANO < NaF+5 %MICRO < NaF < NaF+2.5 %NANO < Pla (both for ERO and ERO+ABR). The highest SH loss was observed for Pla and the lowest for NaF (ERO) and NaF+2.5 %NANO (ERO+ABR), without significant differences among NaF+2.5 %NANO, NaF, and NaF+5 %MICRO. The highest ΔKHN values were observed for NaF+5 %MICRO and NaF+5 %NANO at 5-30 µm, with less marked differences among the groups at 30-70 µm (ERO and ERO+ABR). CONCLUSIONS: The addition of TMP to F varnishes significantly improves protection against ETW in vitro. The use of 5 % nano-sized TMP further enhances such effects. CLINICAL SIGNIFICANCE: F varnishes containing TMP can reduce enamel loss caused by ERO or ERO+ABR.