Association between Tooth Loss and Stroke: A Systematic Review.

This systematic review aims to evaluate the association between tooth loss and stroke. The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were followed. The PECO strategy was used to limit the eligibility criteria. The following databases were used on searches: PubMed, Scopus, Web of Science, The Cochrane Library, LILACS and OpenGrey. We included observational studies performed in adults (Population), in which patients with tooth loss (Exposition) and patients without tooth loss (Comparison) were observed to investigate the association between tooth loss and stroke (Outcome). After searches, the results were submitted to a selection process, followed by data extraction, quality assessment and risk of bias evaluation. The certainty of the evidence was evaluated through GRADE approach. A total of 925 potential studies were retrieved by the searches and 9 were included in this review. Seven of the included articles described an association between tooth loss and stroke. Low risk of bias and a low certainty of the evidence were identified to all studies. The certainty of the evidence may be associated with the observational nature of the included studies. Even though an association between tooth loss and stroke was suggested, the low strength of the current evidence indicated the need for further investigations with a better methodological design to conclude this question.

Biological action of bleaching agents on tooth structure: A review.

The use of bleaching agents to remove stains is one of the main dental procedures to improve the aesthetics of teeth. This review presents the main agents used for tooth whitening, existing clinical protocols, and the structural changes that may occur through their use. The main bleaching agents consist of hydrogen peroxide and carbamide peroxide, which are used in bleaching techniques for vital teeth. These techniques can be performed in the office by a professional or by the individual in a home en-vironment under professional guidance. Bleaching agents come in a variety of concentrations and there are over-the-counter products available on the market with lower concentrations of hydrogen peroxide. Due to the chemical characteristics of the agents, changes in the organic and inorganic content of the tooth structure can be observed. These changes are related to morphological changes characterized by in-creased permeability and surface roughness, such changes compromise the mechanical resistance of the tooth. Furthermore, bleaching agents can promote molecular changes after reaching the dental pulp, resulting in oxidative stress of pulp cells and the release of pro-inflammatory mediators. Despite the bleaching effectiveness, tooth sensitivity is considered the main side effect of use. Therefore, among the heterogeneity of protocols, those that used the bleaching agent for a prolonged time and in lower con-centrations presented more harmful effects on the tooth structure.

Dental Caries and Salivary Oxidative Stress: Global Scientific Research Landscape.

This study aimed to analyze the research trends on salivary oxidative stress associated with dental caries and to perform bibliometric approaches for existing publications on this association. A search was performed using the Web of Science Core Collection, without any restriction of language or publication year. The number of periodicals with the most published articles in this theme, most published authors and keywords were mapped; other metrics were also evaluated such as the countries that have more research on the subject and the period in which there were more publications on the subject. During the knowledge mapping, the most frequent experimental designs were analyzed, type of saliva collection, stage of caries disease, evaluated oxidative parameters were retrieved and analyzed from each manuscript. Between the 43 selected articles, the Journal of Clinical Pediatric Dentistry was the periodical appearing the most with 4 published articles. The authors who published the most were Celec, P., Tothova, L., Hegde, A.M., Shetty, S., Antoniali, C., and Pessan, JP with three articles each, and a total of 180 keywords representing the evolution of the theme. India and Asia were found to be the country and continent with most publications, respectively. Most articles collected non-stimulated total saliva, with total antioxidant capacity being the parameter most often evaluated. The type of study that appeared the most was cross-sectional studies, and articles published in the period of 2017-2022 were the most frequent. Studies show that dental caries can be associated to the changes in salivary oxidative biochemistry with an increase in lipid peroxidation, a biomarker of oxidative damage, and an increase in antioxidant capacity in chronic caries, in response to cariogenic challenge. Some studies evidence the reduction of lipid peroxidation after treatment of the carious lesion. Our findings reveal worldwide research trends, as well as a clearer knowledge of the evolution and future scenarios of this issue, also showing the mechanisms associating dental caries with changes in salivary oxidative biochemical parameters are not clear.

Effects of Photobiomodulation on Oral Mucositis: Visualization and Analysis of Knowledge.

This review article mapped and analyzed the most cited articles on the association of photobiomodulation (PBM) with oral mucositis (OM) and the evolution of clinical protocols in the area. A comprehensive search was performed on the Web of Science Core Collection (WoS-CC) database, leading to the extraction of information such as title, authors, abstract, journal name, number, average of citations, study design, year of publication, institutions, continents, countries, type of laser used, irradiated anatomical points, primary anti-cancer therapy, and laser parameters. Among those, clinical trials and literature reviews were the most common study designs. The main type of laser used was the InGaAlP diode, with a wavelength ranging from 630-660 nm, power going in 40-100 mW, and energy density ranging from 0.375-22 J/cm2. As for the anatomical sites irradiated by PBM, the cheek mucosa, upper and lower lips, lateral tongue, and bottom of the mouth stood out. This analysis highlights an increasing interest in PBM as a supportive treatment in cases of OM, as well as the evolution of the technique, types of laser devices, and protocols used.

Treatment for dental erosion: a systematic review of in vitro studies.

Background: Dental erosion is a chemical loss of the mineralized dental tissue caused by exposure to nonbacterial acids. Different treatment protocols have been adopted with the use of fluoride compounds to promote the formation of a layer of mineral precipitation in eroded lesions. Aim: This systematic review aimed to evaluate the main treatments for dental erosion. Methodology: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and recorded in the Open Science Framework database (OSF) under DOI 10.17605/OSF.IO/XMFNZ. The searches were conducted in six electronic databases (Pubmed, Embase, Web of Science, Cochrane, Scopus, Lilacs) and two grey literature sources (Google Scholar and OpenGrey). The eligibility criteria included in vitro studies that evaluated eroded teeth under treatment with some topical agent. Risk of bias assessment and qualitative synthesis were performed using the Cochrane collaboration's tool for assessing risk of bias modified for in vitro studies. Results: A total of 522 studies were identified, and only four studies that fulfilled our eligibility criteria were included in this review. Among these studies, three were considered to have a low risk of bias, and one to have a high risk of bias. Two studies evaluated the anti-erosion effect of fluoride toothpaste, and the other two assessed the action of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on the surface of human teeth. Among the products analyzed, CPP-ACP was the only one that promoted a significant increase in enamel microhardness and reduced tooth wear. Conclusion: Based on the in vitro studies included in this review, there was no anti-erosion effect after using different fluoride toothpaste. However, it should be considered that one of these studies presented a high risk of bias. On the other hand, studies with CPP-ACP showed anti-erosion efficacy when applied before or after erosive wear.

Methylmercury-induced cytotoxicity and oxidative biochemistry impairment in dental pulp stem cells: the first toxicological findings.

BACKGROUND: Methylmercury (MeHg) is a potent toxicant able to harm human health, and its main route of contamination is associated with the consumption of contaminated fish and other seafood. Moreover, dental amalgams are also associated with mercury release on human saliva and may contribute to the accumulation of systemic mercury. In this way, the oral cavity seems to be the primary location of exposure during MeHg contaminated food ingestion and dental procedures but there is a lack of literature about its effects on dental tissues and the impact of this toxicity on human health. In this way, this study aimed to analyze the effects of different doses of MeHg on human dental pulp stem cells after short-term exposure. METHODS: Dental pulp stem cells from human exfoliated deciduous teeth (SHED) were treated with 0.1, 2.5 and 5 µM of MeHg during 24 h. The MeHg effects were assessed by evaluating cell viability with Trypan blue exclusion assay. The metabolic viability was indirectly assessed by MTT reduction assay. In order to evaluate an indicative of antioxidant defense impairment, cells exposed to 0.1 and 5 µM MeHg were tested by measuring glutathione (GSH) level. RESULTS: It was observed that cell viability decreased significantly after exposure to 2.5 and 5 µM of MeHg, but the metabolic viability only decreased significantly at 5 µM MeHg exposure, accompanied by a significant decrease in GSH levels. These results suggest that an acute exposure of MeHg in concentrations higher than 2.5 µM has cytotoxic effects and reduction of antioxidant capacity on dental pulp stem cells.

Effects of Chronic Ethanol Consumption and Ovariectomy on the Spontaneous Alveolar Bone Loss in Rats.

Postmenopausal estrogen deficiency and ethanol (EtOH) abuse are known risk factors for different diseases including bone tissues. However, little is known about the synergic effects of EtOH abuse and estrogen deficiency on alveolar bone loss in women. The present study evaluated the effects of EtOH chronic exposure and ovariectomy on the alveolar bone loss in female rats. For this, 40 female Wistar rats were randomly divided into 4 groups: control, EtOH exposure, ovariectomy (OVX), and OVX plus EtOH exposure. Initially, half of the animals were ovariectomized at 75 days of age. After that, the groups received distilled water or EtOH 6.5 g/kg/day (20% w/v) for 55 days via gavage. Thereafter, animals were sacrificed and the mandibles were collected, dissected, and separated into hemimandibles. Alveolar bone loss was evaluated by measuring the distance between the cementoenamel junction and the alveolar bone crest through a stereomicroscope in 3 different anatomical regions of the tissue. One-way ANOVA and post hoc Tukey were used to compare groups (p < 0.05). The results showed that the ovariectomy and EtOH exposure per se were able to induce alveolar bone loss, and their association did intensify significantly the effect. Therefore, OVX associated with heavy EtOH exposure increase the spontaneous alveolar bone loss in rats.

Choice of toothpaste for the elderly: an in vitro study.

Hyposalivation and dental root exposure in the elderly are problems that require special oral care. In this context, the characteristics of certain toothpastes are of particular importance. Thus, the aim of this study was to evaluate the cytotoxicity and dentin wear caused by seven different toothpastes. For dentin wear analysis, 40 root dentin specimens were submitted to 20,000 brushing cycles with the different toothpastes and distilled water (control group-CG), using a brushing machine. Dentin surface loss (SL) was measured by contact profilometer. The cytotoxicity of each toothpaste was tested using cultured fibroblasts submitted to a cell-culture-conditioned medium. Fresh medium served as the control. Cell viability was assessed by MTT assay after 24 h of contact with the conditioned media. The data were analyzed statistically by ANOVA, followed by Tukey's test (p < 0.05). The SL of the CG was minimal and significantly lower than that of the Oral B Pro Health (OBPH) group (p < 0.05). All other groups presented SL in between that of the CG and the Oral B Pro Health OBPH group, except for the Sensodyne (SEN) group, which presented SL similar to that of CG (p = 0.05). The SEN group presented a percentage of viable cells similar to that of CG: between 60-89%. All the other toothpastes showed high cytotoxicity, with cell viability less than 50% of the CG. Considering study limitations, we concluded that only one of the seven tested toothpastes exhibited the most desirable toothpaste characteristics for the worldwide growing elderly population (e.g. low cytotoxicity and low-abrasive potential).

Ultrastructural Alterations and Physical Changes on Bovine Dentin After Internal Bleaching with 35 % Hydrogen Peroxide / Alteraciones Ultraestructurales y Cambios Físicos en la Dentina Bovina Después del Blanqueamiento Interior con un 35 % de Peróxido de Hidrógeno

ABSTRACT: The aim of the study was to investigate the effect of internal bleaching on physical proprieties and ultrastructure of the bovine dentin.40 bovine incisors were used, divided in four experimental groups: control group, composed by teeth that did not receive the bleaching agent (G1); teeth submitted to a single internal bleaching session (G2); teeth submitted to two internal bleaching sessions (G3); teeth submitted to three internal bleaching sessions (G4). In each of the sessions, 35 % hydrogen peroxide was applied for 45 minutes on the dentin surface. Tests were performed (microhardness and roughness) and were analyzed using one-way analysis of variance (ANOVA) and Tukey's post-hoc test (p≤0.05). Electromicrographs were captured for quality analysis. In the analysis of the superficial microhardness of the dentin, the internal bleaching reduced the Knoop microhardness since the first session, being observed statistically significant differences between the experimental groups and the control. The surface roughness gradually increased in the G2, G3 and G4 groups, but only G4 presented a statistically significant difference from the others. The qualitatively evaluated electromicrographs showed damage to the dentin ultrastructure, with areas of erosion and greater involvement of the intertubular when compared to peritubular dentin. Internal bleaching with 35 % hydrogen peroxide caused injuries in bovine dentin from the first treatment session. Both modifications in physical properties and dentin ultrastructure have been identified. These changes were intensified the higher the number of dentin internal bleaching sessions was exposed.

RESUMEN: El objetivo de este estudio fue investigar el efecto del blanqueamiento interno sobre las propiedades físicas y la ultraestructura de la dentina bovina. Se utilizaron 40 incisivos bovinos, divididos en cuatro grupos experimentales: grupo de control, compuesto por dientes que no recibieron el agente blanqueador (G1); dientes sometidos a una única sesión interna de blanqueamiento (G2); dientes sometidos a dos sesiones internas de blanqueamiento (G3); dientes sometidos a tres sesiones internas de blanqueamiento (G4). En cada una de las sesiones, se aplicó peróxido de hidrógeno al 35 % durante 45 minutos en la superficie de la dentina. Se realizaron pruebas (microdureza y rugosidad). Los datos se analizaron mediante análisis de varianza de una vía (ANOVA) y prueba post-hoc de Tukey (p≤0,05). Las electromicrografías fueron capturadas para el análisis cualitativo. En el análisis de la microdureza superficial de la dentina, el blanqueamiento interno redujo la microdureza de Knoop desde la primera sesión, observándose diferencias estadísticamente significativas entre los grupos experimentales y el control [NF2]. La rugosidad superficial aumentó gradualmente en los grupos G2, G3 y G4, pero solo G4 presentó una diferencia estadísticamente significativa con respecto a los otros [NF3]. Las electromicrografías evaluadas cualitativamente mostraron daño a la ultraestructura de la dentina, con áreas de erosión y una mayor participación de la dentina intertubular en comparación con la dentina peritubular. El blanqueamiento interno con peróxido de hidrógeno al 35 % causó lesiones en la dentina bovina en la primera sesión del tratamiento. Ambas modificaciones, en propiedades físicas y en la ultraestructura dentinaria, han sido identificadas. Estos cambios se intensificaron a medida que se expuso a mayor número de sesiones de blanqueamiento interno en la dentina.

Wear of depth perception and shade matching outcome in the pre-clinical setting / Percepção da profundidade de desgaste e compatibilidade de cor no ambiente pré-clínico

O presente estudo investigou se a percepção de profundidade de desgaste dental por alunos de graduação tem influência sobre a cor final de restaurações anteriores diretas, realizadas em dentes artificiais. Material e Métodos: Oitenta e um participantes foram divididos em três grupos (n = 27): G1, estudantes do início do curso de odontologia; G2, estudantes de odontologia de nível intermediário; e G3, estudantes de odontologia de nível avançado. Para investigar a percepção de profundidade desgaste dental, cada aluno de graduação recebeu um manequim que continha um incisivo central superior intacto e instruções sobre a técnica de preparação do dente para faceta direta. Todos os grupos foram instruídos a realizar os preparos com 1 mm de profundidade. A profundidade de desgaste dentário foi analisada utilizando um espessímetro. Posteriormente, os dentes foram restaurados com resina composta opaca ou translúcida utilizando-se uma matriz de pré-moldada. A cor foi medida por meio de um espectrofotómetro (L * a * b *). Os dados foram analisados estatisticamente pelo teste KruskalWallis e post hoc de Dunn (α = 5%). Resultados: A profundidade do desgaste dental foi diferente entre todos os grupos (p < 0,05). G1, G2 e G3 obtiveram uma média de 1, 0,5 e 0,8 mm, respectivamente. G3 apresentou maior precisão na profundidade de desgaste dental. Os valores de cor não variaram de acordo com a profundidade de desgaste dental ou para o tipo de resina utilizada na restauração (p > 0,05). Conclusão: A formação técnica e experiência clínica contribuiu para uma melhor percepção de desgaste dental em profundidade por estudantes de graduação em Odontologia. Na configuração pré-clínica, a profundidade de desgaste dental teve pouca ou nenhuma influência sobre a cor final de restaurações anteriores diretas. Além disso, independentemente do tipo de resina composta usada, todas as restaurações realizadas em dentes artificiais tiveram resultado estético similar...

The present study investigated whether the perception of dental wear depth by undergraduate students has influence on the final color of direct anterior restorations performed on artificial teeth. Material and Methods: Eighty-one participants were assigned to one of three groups (n = 27): G1, beginning dental students; G2, intermediate dental students; and G3, advanced dental students. To investigate dental wear depth perception, each undergraduate student received one manikin containing an intact upper central incisor and a flyer instructing the technique of tooth preparation for veneer. All groups were required to prepare 1mm in depth. Dental wear depth was analyzed using a thickness gauge. Subsequently, teeth were restored with opaque or translucent composite resin using a pre-shaped matrix. Color was measured by means of a spectrophotometer (L*a*b* system). Data were statistically analyzed by the Kruskal-Wallis and Dunn’s post hoc tests (α = 5%). Results: Dental wear depth was different among all groups (p < 0.05). G1, G2 and G3 obtained a median of 1 mm, 0.5 mm and 0.8 mm, respectively. G3 presented more accuracy in the dental wear depth. Color values did not vary according to the dental wear depth or to the type of resin composite used in the restoration (p > 0.05). Conclusion: Technical training and clinical experience contribute to the better dental wear depth perception of undergraduate dental students. In the pre-clinical setting, dental wear depth has little or no influence on the final color of direct anterior restorations. Moreover, regardless to the type of resin composite used, all restorations performed on artificial teeth had similar aesthetic outcome...

Choice of toothpaste for the elderly: an in vitro study

Hyposalivation and dental root exposure in the elderly are problems that require special oral care. In this context, the characteristics of certain toothpastes are of particular importance. Thus, the aim of this study was to evaluate the cytotoxicity and dentin wear caused by seven different toothpastes. For dentin wear analysis, 40 root dentin specimens were submitted to 20,000 brushing cycles with the different toothpastes and distilled water (control group-CG), using a brushing machine. Dentin surface loss (SL) was measured by contact profilometer. The cytotoxicity of each toothpaste was tested using cultured fibroblasts submitted to a cell-culture-conditioned medium. Fresh medium served as the control. Cell viability was assessed by MTT assay after 24 h of contact with the conditioned media. The data were analyzed statistically by ANOVA, followed by Tukey’s test (p < 0.05). The SL of the CG was minimal and significantly lower than that of the Oral B Pro Health (OBPH) group (p < 0.05). All other groups presented SL in between that of the CG and the Oral B Pro Health OBPH group, except for the Sensodyne (SEN) group, which presented SL similar to that of CG (p = 0.05). The SEN group presented a percentage of viable cells similar to that of CG: between 60-89%. All the other toothpastes showed high cytotoxicity, with cell viability less than 50% of the CG. Considering study limitations, we concluded that only one of the seven tested toothpastes exhibited the most desirable toothpaste characteristics for the worldwide growing elderly population (e.g. low cytotoxicity and low-abrasive potential).

Left-handed dental students / O estudante de odontologia canhoto

Objectives: to evaluate the frequency of left-handed students and to investigate their difficulties in Operative & Restorative Dentistry, first preclinical discipline of the School of Dentistry, University of São Paulo. Materials and methods: 82 students from both genders participated, who were attending the second year of the course, to whom were applied the Edinburgh Handedness Inventory measurements and a questionnaire about the difficulties encountered by lefty students. Results: in the study sample, we found 6 left-handed students (7%). The greater difficulty reported by them during their laboratorial practice was working in the quadrants on the right side of the manikin’s mouth. Conclusion: therefore, it is clear that Dentistry Schools should be aware of this minority, with regard to the material and equipment availability for lefties, as well as recognition of their difficulties and to orient them to obtain the best performance with minimum discomfort.

Objetivos: Avaliar a frequência de alunos canhotos e investigar suas dificuldades em Dentística Operatória Direta, primeira disciplina pré-clínica da Faculdade de Odontologia da Universidade de São Paulo. Materiais e métodos: Participaram 82 estudantes de ambos os sexos que estavam cursando o segundo ano do curso. Foram aplicados Inventário de Lateralidade de Edimburgo e um questionário sobre as dificuldades encontradas pelos estudantes canhotos. Resultados: Na amostra do estudo foram identificados seis canhotos (7%). A maior dificuldade relatada por eles, durante a prática laboratorial, foi trabalhar nos quadrantes do lado direito da boca do manequim. Conclusão: As Escolas de Odontologia devem estar cientes desta minoria, em relação ao material e disponibilidade de equipamentos para os canhotos, bem como o reconhecimento das suas dificuldades e orientá-los para obter o melhor desempenho com o mínimo desconforto.