Effects of Dentifrices Differing in Fluoride Content on Remineralization Characteristics of Dentin in vitro

Objectives: The aim of this study was to compare the caries preventive effect of highly fluoridated dentifrices and gels on sound dentin as well as on artificial dentin caries-like lesions. Methods: Bovine dentin specimens (n = 240), with 2 different surfaces each (1 sound surface [sound treatment (ST)] and one caries lesion [demineralized treatment (DT)]), were prepared and randomly allocated to one highly (6 × 120 min demineralization/day [H]) and one lowly cariogenic (6 × 60 min demineralization/day [L]) pH-cycling model. Treatments during pH-cycling (28 days) were: brushing 2×/ day with: 0 ppm F [H0/L0], 1,450 ppm F [H1,450/L1,450], 2,800 ppm F [H2,800/L2,800], 5,000 ppm F [H5,000/L5,000], 5,000 ppm F plus TCP [H5,000+TCP/L5,000+TCP], and 12,500 ppm F [H12,500/ L12,500] containing dentifrices/gels. Dentifrice/gel slurries were prepared with deionized water (1: 2 wt/wt). Differences in integrated mineral loss (ΔΔZ) and Δ lesion depth were calculated between values before and after pH-cycling using transversal microradiography. Results: The correlation between ΔΔZDT and F– was strong for the highly (rH = 0.691; p < 0.001) and moderate (rL = 0.500; p < 0.001) for the lowly cariogenic model, indicating a fluoride dose-response for both. Significant differences for ΔΔZDT and ΔΔZST could be found between H0, H1,450, H5,000, and H12,500 as well as L0, L5,000, and L125,000 (p ≤ 0.046; analysis of covariance [ANCOVA]). Except for 0 ppm F–, no significant difference in ΔΔZST and ΔΔZDT could be found between the highly and lowly cariogenic model (p ≥ 0.056; ANCOVA). Conclusion: For both pH-cycling conditions a dose-response for fluoride could be revealed. For elderly people with exposed root surfaces, the use of gels containing 12,500 ppm F instead of regularly (1,450 ppm F) or highly (5,000 ppm F) fluoridated dentifrices should be further investigated, as it offered higher cariespreventive effects in vitro

Higher prevalence of dental caries and periodontal problems among refugees: A scoping review.

BACKGROUND We assessed the prevalence data on oral health diseases, namely dental caries and periodontitis, among refugees and asylum seekers worldwide. METHODS A systematic search of Scopus, Embase, and PubMed retrieved 1225 records; following title and abstract screening, 58 studies remained for full-text eligibility screening based on pre-defined inclusion criteria. Twenty-six studies were included in the review. RESULTS Dental caries and tooth loss due to caries were high in refugee populations, regardless of their age, gender, or nationality. The adult population had a mean decayed, missing, and filled teeth (DMFT) index score of 9.2 (standard deviation (SD) = 2.3); children had a score of 3.1 (SD = 1.1) for deciduous teeth and 2.5 (SD = 1.1) for permanents. Caries prevalence among refugees ranged from 4.6% to 98.7%, and gingivitis from 5.7% to 100%, indicating a high heterogeneity in their oral health. Regarding oral health accessibility, 17% to 72% of refugees had never been to a dentist, showing a very low level of accessibility to dental health services. CONCLUSIONS Interventions and policies need to be designed to reduce oral health inequalities among refugee populations and asylum seekers, and host countries must implement strategies to increase their access to oral health care. Existing data should be used to set priorities for improving the oral health of refugees. REGISTRATION Open Science Framework: https://doi.org/10.17605/OSF.IO/SU59K

Demineralization Inhibitory Effects of Highly Concentrated Fluoride Dentifrice and Fluoride Gels/Solutions on Sound Dentin and Artificial Dentin Caries Lesions in vitro

Objectives: The aim of this in vitro study was to compare the demineralization inhibitory effect of gels/solutions used in combination with either standard or highly fluoridated dentifrices on sound dentin as well as on artificial dentin carieslike lesions. Methods: Bovine dentin specimens (n = 240) with two different surfaces each (sound [ST] and artificial caries lesion [DT]) were prepared and randomly allocated to twelve groups. Weekly interventions during pH-cycling (28 days, 6 × 120 min demineralization/day) were: the application of gels/solutions containing amine fluoride/sodium fluoride (12,500 ppm F [ppm]; pH = 4.4; AmF); NaF (12,500 ppm; pH = 6.6; NaF1); NaF (12,500 ppm; pH = 6.3; NaF2); silver diamine fluoride (14,200 ppm; pH = 8.7; SDF); acidulated phosphate fluoride (12,500 ppm; pH = 3.8; APF), and no intervention (standard control; S). Furthermore, half of the specimens in each group were brushed (10 s; twice per day) with dentifrice slurries containing either 1,450 ppm (e.g., AmF1450) or 5,000 ppm (e.g., AmF5000). Differences in integrated mineral loss (ΔΔZ) and lesion depth (ΔLD) were calculated between values before and after pH-cycling using transversal microradiography. Results: After pH-cycling Ss showed significantly increased ΔZDT and LDDT values, indicating further demineralization. In contrast, except for one, all groups including fluoride gels/solutions showed significantly decreased ΔZDT values. Additional use of most fluoride gels/solutions significantly enhanced mineral gain, mainly in the surface area; however, acidic gels/solutions seemed to have negative effects on lesion depths. Significance: Under the present pH-cycling conditions the highly fluoridated dentifrice significantly reduced caries progression and additional application of nearly all of the fluoride gels/solutions resulted in remineralization. However, there was no difference in the remineralizing capacity of fluoride gels/solutions when used in combination with either standard or highly fluoridated dentifrices

Electronic Cigarettes, Heated Tobacco Products, and Oral Health: A Systematic Review and Meta- Analysis.

Smokers employing electronic nicotine delivery systems (ENDS) and heated tobacco products (HTP) are currently the most common types of smoking patients seen in the dental practice. Both types of smoking are currently viewed as less harmful than cigarette smoking. However, many studies already indicate that they could harm oral health. This systematic review and meta-analysis aimed to collect a comprehensive overview of the actual knowledge regarding ENDS and HTP from a clinical and a laboratory perspective. Publications available through PubMed, Embase, the Web of Science, Scopus, and Google Scholar were used to summarize the effects of ENDS and HTP on oral health. Six surveys on self-perceived gum disease (T2 = 9.47 I2 = 99.32%), three cross-sectional studies reporting the BOP score (T2 = 8.68 I2 = 99.13%), and four in vitro studies on apoptosis after vaping exposure in human oral fibroblasts (T 2 = 8.10 I2 = 91.50%) were separately analyzed. The risk of bias ranged from critical to low. Both ENDS and HTP seem to have detrimental effects on periodontal and peri-implant parameters, and laboratory tests confirmed the presence of carcinogenic and inflammatory biomarkers. flavored e-liquids may also be a caries risk factor. Comprehensive smoking counseling should be carried out with all types of smoking patients, investigating the type of habit in terms of duration, nicotine percentage, and additional flavorings. Additional research is necessary to assess the long-term effects of alternative tobacco products on oral health

Long-term caries prevention of dental sealants and fluoride varnish in children with autism spectrum disorders: a retrospective cohort study.

The aim was to compare two strategies for caries prevention in children with Autism Spectrum Disorders (ASDs). Participants were retrospectively retrieved and divided in two groups. Group one had first permanent molars treated with fluoride varnishes, FA group (n = 92, 9.43 ± 2.44 years) whilst the second, with dental sealant plus fluoride varnishes, FA + S group (n = 140, 7.77 ± 2.57 years). Logistic and multivariate analysis were run to evaluate the caries incidence, the retention rate of sealants, and background factors associated with caries risk over a period of at least 11 years. Survival rates from dental caries were statistically significantly higher in the FA + S group compared to the FA group (LogRank test p < 0.01). Dental sealant plus fluoride varnish played as a protective factor towards the development of caries (HR = 0.25 95%CI = 0.00/0.55 and HR = 0.34 95%CI = 0.00/0.66 in the upper right and left first molars; HR = 0.32 95%CI = 0.00/0.66 and HR = 0.26 95%CI = 0.00/0.58 in the lower right and left first molars). Dental sealants retention rate was high, ranging between 58.02% and 64.29%. No baseline variable was statistically significantly associated to the risk of caries development. Combined dental sealant and fluoride varnish application was more effective in reducing caries risk in first permanent molars of ASDs children than fluoride varnish alone. This preventive strategy should be therefore routinely applied in high caries risk patients as ASDs children

ФОРМИРОВАНИЕ ГЕОТЕХНИЧЕСКИХ СВОЙСТВ ПРИКОНТУРНЫХ ГРУНТОВЫХ СЛОЁВ ПОДЗЕМНОГО ТУННЕЛЯ ЭЛЕКТРОХИМИЧЕСКИМ МЕТОДОМ

Строительство подземных сооружений и туннелей является приоритетным направлением развития для крупных городов, поверхность которых плотно застроена постройками и объектами городской инфраструктуры. При анализе процессов возведения тоннелей закрытым способом строительства можно отметить, что технологии строительства тоннелей имеют ряд недостатков (повышенные расходы на материалы, высокую энергоёмкость и трудоёмкость, низкое качество уплотнения отделки и т.д.), которые существенно снижают технико-экономические показатели и эксплуатационные свойства сооружений

Evaluating the Effectiveness of the Nudge Theory in Improving the Oral Self-Care of Schoolchildren with Refugee and Immigrant Backgrounds in Mashhad, Iran.

Nudge theory proposes using subtle interventions to encourage individuals to make better decisions. The aim of this study was to evaluate the effectiveness of the Nudge theory in plaque control and assess caries experience among third-grade primary schoolchildren with refugee and immigrant backgrounds in Mashhad, Iran. Moreover, Afghan and Iranian schoolchildren were compared to assess differences in oral health outcomes. A quasi-experimental field trial was conducted in three public primary schools, comprising 309 participants approximately 9 years old. Interventions were randomly assigned to three schools: School I Messages based on Social Norms (MSN), School II Messages based on Fear of Negative Outcome (MFNO), and School III control group (C). MSN and MFNO received customized motivational video clips at baseline, while C only received Oral hygiene instruction (OHI). All participants received OHI, a brush, and toothpaste. Baseline plaque index (PI) and caries experience in primary and permanent dentition (dmft/DMFT) were recorded. PI was reassessed at two weeks, two months, and six months post-intervention. All data were subjected to statistical analysis. The mean PI decreased significantly in all three groups at the two-week follow-up (p < 0.01). The PI improvements declined over a six-month follow-up period in all groups, and the mean PI difference after six months compared to the pre-intervention was significant only in MSN and MFNO (p < 0.01), while C reverted almost to the pre-study level. Schoolchildren with at least one filled tooth or Iranian nationality showed a greater PI reduction (p < 0.01, p = 0.05). The overall mean ± SD dmft and DMFT were 4.24 ± 2.11 and 1.70 ± 1.24, respectively. Among all the examined participants, 32 (10.40%) individuals were caries-free. The mean dmft was statistically significantly higher in Afghan children than in Iranians (p = 0.01). MSN was more effective on PI reduction in the short term, while MFNO was more long-lasting. Using the Nudge theory via visual aids was more effective in motivating children to perform better oral self-care than solely traditional OHI

Исследование свойств и состава руды с целью усовершенствования извлечения вольфрамсодержащих компонентов

The aim of this in vitro study was to investigate the effect of erbium:yttrium-aluminum-garnet (Er:YAG) laser irradiation on dentinal collagen by transmission electron microscopy and to analyze the resin-dentin interface by scanning electron microscopy. A tensile bond strength test was also applied. Specimens from 69 sound human third molars were randomly divided into three groups: control (no laser), and two irradiated groups, laser 250 (250 mJ/2 Hz) and laser 400 (400 mJ/4 Hz). Then, specimens were restored with two adhesive systems, an etch-and-rinse or a self-etch system. Although ultrastructural examination showed a modified surface in the irradiated dentin, there was no statistical difference in bond strength values between the laser groups and controls (P < 0.05). In conclusion, the use of Er:YAG laser for ablating human dentin did not alter the main adhesion parameters when compared with those obtained by conventional methods, thus reinforcing its use in restorative dentistry.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[97/10823-0]Conselho Nacional de Desenvolvimento Cientfico e Tecnologico e Conselho Nacional de Pesquisa (CNPq)[303798/2005-0]Coordena ao de Aperfei oamento de Pessoal de Nivel Superior (CAPES), Brazi

Análise quantitativa da remoção de esmalte dental durante a técnica de microabrasão

Objetivo: Quantificar, por meio de perfilometria, a profundidade de esmalte dental removido durante o emprego de uma técnica de microabrasão utilizando-se ácido clorídrico e abrasão manual com espátula plástica. Método: Trinta e seis espécimes obtidos de terceiros molares humanos foram polidos, para obtenção de superfícies planas, e divididos em 3 grupos (n = 12) de acordo com os diferentes tratamentos recebidos: tratamento placebo com água deionizada, como controle negativo (CG); microabrasão com ácido clorídrico a 6.6%, OpalustreTM (G1); e ácido clorídrico a 6%, Whiteness RMTM (G2). A microabrasão foi realizada, de forma padronizada, submetendo os espécimes a 4 ciclos de 10 segundos cada e abrasão manual utilizando-se uma espátula plástica com carga de 200 g. A perda da superfície de esmalte foi medida após cada um dos ciclos de tratamento por meio de perfilômetro de contato. Resultados: Após os primeiros 10 segundos de abrasão, já foi encontrada perda de esmalte em ambos os grupos tratados (G1 e G2). Nos grupos G1 e G2, a cada ciclo de 10 segundos, foi observado um aumento significativo na perda de esmalte (p ≤ 0.05). Após 4 abrasões de 10 segundos cada, as médias de perda de esmalte nos grupos tratados foram 46.04 μm (G1) e 54.65 μm (G2). Foi encontrada uma diferença significativa entre G1 e G2 com relação à perda de esmalte após 30 e 40 segundos de microabrasão. Relevância: Os resultados deste estudo fornecem referências para a realização do procedimento de microabrasão em esmalte dental com segurança, utilizando-se ácido clorídrico e abrasão manual com espátula plástica.Objective: To quantify, by means of profi lometry, the removal of dental enamel during the use of a microabrasion technique involving the use of hydrochloric acid and manual abrasion with a plastic spatula. Method: Thirty six specimens obtained from human third molars were polished to obtain fl at surfaces and divided into 3 groups (n = 12) according to the different treatments received: A placebo treatment with deionized water as a negative control (CG); microabrasion with 6.6% hydrochloric acid, OpalustreTM (G1); and microabrasion with 6% hydrochloric acid, Whiteness RMTM (G2). The microabrasion was performed in a standardized manner by submitting the specimens to 4 cycles of 10 seconds each and manual abrasion using a plastic spatula (200 g load). The loss of enamel surface was measured after each cycle of treatment by contact profi lometry. Results: Enamel loss was already observed after the fi rst 10 seconds of abrasion with hydrochloric acid in both treated groups (G1 and G2). After 4 abrasions of 10 seconds each, the average fi nal enamel losses in the treated groups were 46.04 μm (G1) and 54.65 μm (G2). In the G1 and G2 groups, a signifi cant increase in enamel wear was detected in each cycle in comparison to the control group (p ≤ 0.05). A signifi cant difference in enamel loss between G1 and G2 was found after 30 and 40 seconds of microabrasion. Relevance: The results of this study provide objective data for safely performing the microabrasion technique on dental enamel using hydrochloric acid and manual abrasion using a plastic spatula