Oral hygiene products, medications and drugs - hidden aetiological factors for dental erosion.

Acidic or EDTA-containing oral hygiene products and acidic medicines have the potential to soften dental hard tissues. The low pH of oral care products increases the chemical stability of some fluoride compounds and favours the incorporation of fluoride ions in the lattice of hydroxyapatite and the precipitation of calcium fluoride on the tooth surface. This layer has some protective effect against an erosive attack. However, when the pH is too low or when no fluoride is present these protecting effects are replaced by direct softening of the tooth surface. Oral dryness can occur as a consequence of medication such as tranquilizers, antihistamines, antiemetics and antiparkinsonian medicaments or of salivary gland dysfunction. Above all, patients should be aware of the potential demineralization effects of oral hygiene products with low pH. Acetyl salicylic acid taken regularly in the form of multiple chewable tablets or in the form of headache powder, as well as chewing hydrochloric acids tablets for the treatment of stomach disorders, can cause erosion. There is most probably no direct association between asthmatic drugs and erosion on the population level. Consumers and health professionals should be aware of the potential of tooth damage not only by oral hygiene products and salivary substitutes but also by chewable and effervescent tablets. Several paediatric medications show a direct erosive potential in vitro. Clinical proof of the occurrence of erosion after use of these medicaments is still lacking. However, regular and prolonged use of these medicaments might bear the risk of causing erosion. Additionally, it can be assumed that patients suffering from xerostomia should be aware of the potential effects of oral hygiene products with low pH and high titratable acidity.

Erosion in relation to nutrition and the environment.

When considering the erosive potential of a food or drink, a number of factors must be taken into account. pH is arguably the single most important parameter in determining the rate of erosive tissue dissolution. There is no clear-cut critical pH for erosion as there is for caries. At low pH, it is possible that other factors are sufficiently protective to prevent erosion, but equally erosion can progress in acid of a relatively high pH in the absence of mitigating factors. Calcium and phosphate concentration, in combination with pH, determine the degree of saturation with respect to tooth minerals. Solutions supersaturated with respect to enamel or dentine will not cause them to dissolve, meaning that given sufficient common ion concentrations erosion will not proceed, even if the pH is low. Interestingly, the addition of calcium is more effective than phosphate at reducing erosion in acid solutions. Today, several calcium-enriched soft drinks are on the market, and acidic products with high concentrations of calcium and phosphorus are available (such as yoghurt), which do not soften the dental hard tissues. The greater the buffering capacity of the drink or food, the longer it will take for the saliva to neutralize the acid. A higher buffer capacity of a drink or foodstuff will enhance the processes of dissolution because more release of ions from the tooth mineral is required to render the acid inactive for further demineralization. Temperature is also a significant physical factor; for a given acidic solution, erosion proceeds more rapidly the higher the temperature of that solution. In recent years, a number of interesting potentially erosion-reducing drink and food additives have been investigated.

The future of fluorides and other protective agents in erosion prevention

The effectiveness of fluoride in caries prevention has been convincingly proven. In recent years, researchers have investigated the preventive effects of different fluoride formulations on erosive tooth wear with positive results, but their action on caries and erosion prevention must be based on different requirements, because there is no sheltered area in the erosive process as there is in the subsurface carious lesions. Thus, any protective mechanism from fluoride concerning erosion is limited to the surface or the near surface layer of enamel. However, reports on other protective agents show superior preventive results. The mechanism of action of tin-containing products is related to tin deposition onto the tooth surface, as well as the incorporation of tin into the near-surface layer of enamel. These tin-rich deposits are less susceptible to dissolution and may result in enhanced protection of the underlying tooth. Titanium tetrafluoride forms a protective layer on the tooth surface. It is believed that this layer is made up of hydrated hydrogen titanium phosphate. Products containing phosphates and/or proteins may adsorb either to the pellicle, rendering it more protective against demineralization, or directly to the dental hard tissue, probably competing with H(+) at specific sites on the tooth surface. Other substances may further enhance precipitation of calcium phosphates on the enamel surface, protecting it from additional acid impacts. Hence, the future of fluoride alone in erosion prevention looks grim, but the combination of fluoride with protective agents, such as polyvalent metal ions and some polymers, has much brighter prospects.

Fluoride varnishes containing calcium glycerophosphate: fluoride uptake and the effect on in vitro enamel erosion

OBJECTIVES Calcium glycerophosphate (CaGP) was added to fluoride varnishes to analyze their preventive effect on initial enamel erosion and fluoride uptake: potassium hydroxide (KOH)-soluble and KOH-insoluble fluoride bound to enamel. MATERIALS AND METHODS This study was carried out in two parts. Part 1: 108 enamel samples were randomly distributed into six varnish groups: base varnish (no active ingredients); Duraphat® (2.26 %NaF); Duofluorid® (5.63 %NaF/CaF2); experimental varnish 1 (1 %CaGP/5.63 %NaF/CaF2); experimental varnish 2 (5 %CaGP/5.63 %NaF/CaF2); and no varnish. Cyclic demineralization (90 s; citric acid, pH = 3.6) and remineralization (4 h) was made once a day, for 3 days. Change in surface microhardness (SMH) was measured. Part 2: 60 enamel samples were cut in half and received no varnish (control) or a layer of varnish: Duraphat®, Duofluorid®, experimental varnishes 1 and 2. Then, KOH-soluble and KOH-insoluble fluoride were analyzed using an electrode. RESULTS After cyclic demineralization, SMH decreased in all samples, but Duraphat® caused less hardness loss. No difference was observed between varnishes containing CaGP and the other varnishes. Similar amounts of KOH-soluble and insoluble fluoride was found in experimental varnish 1 and Duofluorid®, while lower values were found for experimental varnish 2 and Duraphat®. CONCLUSION The addition of CaGP to fluoride varnishes did not increase fluoride bound to enamel and did not enhance their protection against initial enamel erosion. CLINICAL RELEVANCE We observe that the fluoride varnishes containing CaGP do not promote greater amounts of fluoride bound to enamel and that fluoride bound to enamel may not be closely related to erosion prevention.

Bone Conditioned Medium: Preparation and Bioassay.

Autologous bone grafts are widely used in oral and maxillofacial surgery, orthopedics, and traumatology. Autologous bone grafts not only replace missing bone, they also support the complex process of bone regeneration. This favorable behavior of autografts is attributed to the three characteristics: osteoconductivity, osteogenicity, and osteoinductivity. However, there is another aspect: Bone grafts release a myriad of molecules, including growth factors, which can target mesenchymal cells involved in bone regeneration. The paracrine properties of bone grafts can be studied in vitro by the use of bone-conditioned medium (BCM). Here we present a protocol on how to prepare bone-conditioned medium from native pig cortical bone, and bone that underwent thermal processing or demineralization. Cells can be directly exposed to BCM or seeded onto biomaterials, such as collagen membranes, previously soaked with BCM. We give examples for in vitro bioassays with mesenchymal cells on the expression of TGF-β regulated genes. The presented protocols should encourage to further reveal the paracrine effects of bone grafts during bone regeneration and open a path for translational research in the broad field of reconstructive surgery.

Biomaterials for promoting periodontal regeneration in human intrabony defects: a systematic review

Intrabony periodontal defects are a frequent complication of periodontitis and, if left untreated, may negatively affect long-term tooth prognosis. The optimal outcome of treatment in intrabony defects is considered to be the absence of bleeding on probing, the presence of shallow pockets associated with periodontal regeneration (i.e. formation of new root cementum with functionally orientated inserting periodontal ligament fibers connected to new alveolar bone) and no soft-tissue recession. A plethora of different surgical techniques, often including implantation of various types of bone graft and/or bone substitutes, root surface demineralization, guided tissue regeneration, growth and differentiation factors, enamel matrix proteins or various combinations thereof, have been employed to achieve periodontal regeneration. Despite positive observations in animal models and successful outcomes reported for many of the available regenerative techniques and materials in patients, including histologic reports, robust information on the degree to which reported clinical improvements reflect true periodontal regeneration does not exist. Thus, the aim of this review was to summarize, in a systematic manner, the available histologic evidence on the effect of reconstructive periodontal surgery using various types of biomaterials to enhance periodontal wound healing/regeneration in human intrabony defects. In addition, the inherent problems associated with performing human histologic studies and in interpreting the results, as well as certain ethical considerations, are discussed. The results of the present systematic review indicate that periodontal regeneration in human intrabony defects can be achieved to a variable extent using a range of methods and materials. Periodontal regeneration has been observed following the use of a variety of bone grafts and substitutes, guided tissue regeneration, biological factors and combinations thereof. Combination approaches appear to provide the best outcomes, whilst implantation of alloplastic material alone demonstrated limited, to no, periodontal regeneration.

Influence of root canal disinfectants on growth factor release from dentin

INTRODUCTION During dentinogenesis, growth factors become entrapped in the dentin matrix that can later be released by demineralization. Their effect on pulpal stem cell migration, proliferation, and differentiation could be beneficial for regenerative endodontic therapies. However, precondition for success, as for conventional root canal treatment, will be sufficient disinfection of the root canal system. Various irrigation solutions and intracanal dressings are available for clinical use. The aim of this study was 2-fold: to identify a demineralizing solution suitable for growth factor release directly from dentin and to evaluate whether commonly used disinfectants for endodontic treatment will compromise this effect. METHODS Dentin disks were prepared from extracted human teeth and treated with EDTA or citric acid at different concentrations or pH for different exposure periods. The amount of transforming growth factor-β1 (TGF-β1), fibroblast growth factor 2, and vascular endothelial growth factor were quantified via enzyme-linked immunosorbent assay and visualized by gold labeling. Subsequently, different irrigation solutions (5.25% sodium hypochloride, 0.12% chlorhexidine digluconate) and intracanal dressings (corticoid-antibiotic paste, calcium hydroxide: water-based and oil-based, triple antibiotic paste, chlorhexidine gel) were tested, and the release of TGF-β1 was measured after a subsequent conditioning step with EDTA. RESULTS Conditioning with 10% EDTA at pH 7 rendered the highest amounts of TGF-β1 among all test solutions. Fibroblast growth factor 2 and vascular endothelial growth factor were detected after EDTA conditioning at minute concentrations. Irrigation with chlorhexidine before EDTA conditioning increased TGF-β1 release; sodium hypochloride had the opposite effect. All tested intracanal dressings interfered with TGF-β1 release except water-based calcium hydroxide. CONCLUSIONS Growth factors can be released directly from dentin via EDTA conditioning. The use of disinfecting solutions or medicaments can amplify or attenuate this effect.

Development and Characterization of an in vitro Four-species Anaerobic Dental Biofilm Model

Dental caries is the most common chronic disease worldwide. It is characterized by the demineralization of tooth enamel caused by acid produced by cariogenic dental bacteria growing on tooth surfaces, termed bacterial biofilms. Cariogenesis is a complex biological process that is influence by multiple factors and is not attributed to a sole causative agent. Instead, caries is associated with multispecies microbial biofilm communities composed of some bacterial species that directly influence the development of a caries lesion and other species that are seemingly benign but must contribute to the community in an uncharacterized way. Clinical analysis of dental caries and its microbial populations is challenging due to many factors including low sensitivity of clinical measurement tools, variability in saliva chemistry, and variation in the microbiota. Our laboratory has developed an in vitro anaerobic biofilm model for dental carries to facilitate both clinical and basic research-based analyses of the multispecies dynamics and individual factors that contribute to cariogenicity. The rational for development of this system was to improve upon the current models that lack key elements. This model places an emphasis on physiological relevance and ease of maintenance and reproducibility. The uniqueness of the model is based on integrating four critical elements: 1) a biofilm community composed of four distinct and representative species typically associated with dental caries, 2) a semi-defined synthetic growth medium designed to mimic saliva, 3) physiologically relevant biofilm growth substrates, and 4) a novel biofilm reactor device designed to facilitate the maintenance and analysis. Specifically, human tooth sections or hydroxyapatite discs embedded into poly(methyl methacrylate) (PMMA) discs are incubated for an initial 24 hr in a static inverted removable substrate (SIRS) biofilm reactor at 37°C under anaerobic conditions in artificial saliva (CAMM) without sucrose in the presence of 1 X 106 cells/ml of each Actinomyces odontolyticus, Fusobacterium nucleatum, Streptococcus mutans, and Veillonella dispar. During days 2 and 3 the samples are maintained continually in CAMM with various exposures to 0.2% sucrose; all of the discs are transferred into fresh medium every 24 hr. To validate that this model is an appropriate in vitro representation of a caries-associated multispecies biofilm, research aims were designed to test the following overarching hypothesis: an in vitro anaerobic biofilm composed of four species (S. mutans, V. dispar, A. odontolyticus, and F. nucleatum) will form a stable biofilm with a community profile that changes in response to environmental conditions and exhibits a cariogenic potential. For these experiments the biofilms as described above were exposed on days 2 and 3 to either CAMM lacking sucrose (no sucrose), CAMM with 0.2% sucrose (constant sucrose), or were transferred twice a day for 1 hr each time into 0.2% sucrose (intermittent sucrose). Four types of analysis were performed: 1) fluorescence microscopy of biofilms stained with Syto 9 and hexidium idodine to determine the biofilm architecture, 2) quantitative PCR (qPCR) to determine the cell number of each species per cm2, 3) vertical scanning interferometry (VSI) to determine the cariogenic potential of the biofilms, and 4) tomographic pH imaging using radiometric fluorescence microscopy after exposure to pH sensitive nanoparticles to measure the micro-environmental pH. The qualitative and quantitative results reveal the expected dynamics of the community profile when exposed to different sucrose conditions and the cariogenic potential of this in vitro four-species anaerobic biofilm model, thus confirming its usefulness for future analysis of primary and secondary dental caries.

El fosfato de calcio amorfo y su papel en la remineralización de lesiones incipientes de esmalte

Con el conocimiento actual de la enfermedad de caries, los conceptos de tratamientos, originalmente invasivos y mutilantes, fueron evolucionando conjuntamente al conocerse que dicha lesión surge a raíz del desequilibrio producido en el proceso fisiológico desmineralización-remineralización (DES/REM) 10. Con la consolidación de la odontología adhesiva, la terapéutica actual se basa en 3 objetivos primordiales: diagnóstico precoz, tratamientos preventivos no invasivos o de invasión mínima y máxima conservación de los tejidos dentarios. La remineralización es un proceso de precipitación de calcio, fosfatos y otros iones en la superficie o dentro del esmalte parcialmente desmineralizado. En este artículo haremos una reseña de los métodos terapéuticos actuales de los que disponemos para realizar dicha remineralización.

Terapêutica da osteopénia e osteoporose em mulheres com anorexia nervosa

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Hearing sensitivity and bone mineral density in older adults: the Health, Aging and Body Composition Study

Bone mineral density (BMD) may be associated with hearing loss in older adults. Demineralization of the cochlear capsule has been associated with hearing loss in those with Paget's disease of the bone and otosclerosis. Osteoporosis may also result in cochlear capsule demineralization. We hypothesized that lower hip BMD and lower heel ultrasound measurements would be associated with hearing loss in a population-based sample of 2,089 older black and white men and women. Bone parameters and hearing function were measured at the fourth clinical follow-up visit. Audiometric threshold testing was used to measure air- and bone-conduction hearing sensitivity. BMD of the hip and its subregions was measured using dual-energy X-ray absorptiometry. Calcaneal bone measurements [broadband ultrasound attenuation (BUA), speed of sound (SOS) and the quantitative ultrasound index (QUI)] were obtained using heel ultrasound. After adjusting for known hearing loss risk factors, no association was found between hearing and any of the bone measurements in whites and black women. In black men, however, lower hip BMD was associated with higher odds of hearing loss; for each standard deviation decrease in total hip BMD, the odds of hearing loss were 1.41 (95% confidence interval 1.08, 1.83), 1.39 (95% CI 1.07, 1.82) for femoral neck BMD and 1.65 (95% CI 1.26, 2.16) for trochanter BMD. Conductive hearing loss was associated with lower heel ultrasound measurements, though only among white men. The results of this study are mixed and inconclusive. Lower BMD of the hip and its subregions was associated with hearing loss among black men, but not among whites or black women. Lower measurements on heel ultrasound were associated with conductive hearing loss, though only among white men. These results suggest that axial and appendicular bone parameters may be modestly associated with hearing loss in older men, but not in women.

Expanding the biomass resource:sustainable oil production via fast pyrolysis of low input high diversity biomass and the potential integration of thermochemical and biological conversion routes

Waste biomass is generated during the conservation management of semi-natural habitats, and represents an unused resource and potential bioenergy feedstock that does not compete with food production. Thermogravimetric analysis was used to characterise a representative range of biomass generated during conservation management in Wales. Of the biomass types assessed, those dominated by rush (Juncus effuses) and bracken (Pteridium aquilinum) exhibited the highest and lowest volatile compositions respectively and were selected for bench scale conversion via fast pyrolysis. Each biomass type was ensiled and a sub-sample of silage was washed and pressed. Demineralization of conservation biomass through washing and pressing was associated with higher oil yields following fast pyrolysis. The oil yields were within the published range established for the dedicated energy crops miscanthus and willow. In order to examine the potential a multiple output energy system was developed with gross power production estimates following valorisation of the press fluid, char and oil. If used in multi fuel industrial burners the char and oil alone would displace 3.9 × 105 tonnes per year of No. 2 light oil using Welsh biomass from conservation management. Bioenergy and product development using these feedstocks could simultaneously support biodiversity management and displace fossil fuels, thereby reducing GHG emissions. Gross power generation predictions show good potential.

The health and nutritional status of multiethnic perimenopausal women

An integrated, dual-phase study design assessed the health and nutritional status and practices of African-American (A-A), Caribbean (A-C), and white non-Hispanic (W-A) women during perimenopause (40–55 years). During Phase I, four focus groups (n = 37) of male and female participants discussed the health and social implications of perimenopause. A conceptual framework for the main study (Phase II) was developed from the focus groups' findings, in concert with the main study's specific aims and objectives. ^ The main study, a cross-sectional survey, quantitatively assessed the health and nutritional status of a convenience sample of 109 women (25 A-A, 31 A-C and 53 W-A), who met specific eligibility criteria. Using seven instruments, sociodemographic, dietary, medical, reproductive health, health practice and anthropometric data were collected. ^ The groups were of comparable age, education, and socioeconomic status (SES). Despite these similarities, statistically significant interethnic nutritional status differences were found. Significantly more total energy and energy from fat were consumed by A-A than W-A and A-C women. Also, significantly more A-A and A-C than W-A women were overweight or obese with android-type weight patterning. ^ Overall, iron and calcium Recommended Dietary Allowances (RDA's) were not met by 35% and 68% of participants, respectively. Iron deficiency anemia was reported by 29% of participants while 33% reported heavier menstrual bleeding. Coupled with suboptimal iron intakes, this is likely to present a serious public health problem. Similarly, increased bone demineralization characteristic of perimenopause, coupled with suboptimal calcium intakes could precipitate another public health problem, osteoporosis. ^ Participants had different expectations about the role of medical care during perimenopause. Significantly more white (57%) than black (38% [A-A and AC]) women sought medical attention for symptoms. Whereas Hormone Replacement Therapy (HRT) was prescribed for 25% of them, only 13% were compliant at enrollment. ^ The trends and statistically significant findings of this study have huge public health policy implications. It is imperative that appropriate policies are formulated to ensure that America's ethnically diverse perimenopausal women have ready access to culturally appropriate care. This would optimize their health outcomes, and enhance their quality of life and productive capacities at this critical juncture of their lives. ^

Saúde oral e cuidados primários em Odontopediatria

Introdução: A cárie dentária é uma doença multifatorial, infeciosa, transmissível e dependente da dieta, que provoca a desmineralização das estruturas dentárias. Devido a esta natureza etiológica multifatorial é fundamental o aumento da sensibilização e educação das crianças e pais, quer por profissionais de saúde, quer pelos professores em ambiente escolar. A aquisição de hábitos de higiene oral e nutricionais adequados pela criança é um fator imperativo para a manutenção de uma boa saúde oral. Objetivos: Avaliação da Saúde Oral e cuidados primários num grupo de crianças e adolescentes pertencentes ao Agrupamento de Escolas de Alijó. Método: A amostra é constituída por 216 alunos do Agrupamento de Escolas de Alijó, agrupados em três escalões etários: 6-9 anos, 10-14 anos e 15-16 anos. Foi realizada uma observação oral com base no índice de higiene oral simplificado e no índice de cárie (CPOd/cpod- Dentes Cariados, Perdidos e Obturados). Após esta observação foi aplicado um questionário escrito sobre diversos temas relacionados com a saúde oral. Resultados: A percentagem de crianças livres de lesões cariosas aos 6, 12 e 15 anos foi de 33,3%, 28,4% e 16,2%, respetivamente. Os valores da média de número de escovagens diárias aumentam de acordo com a faixa etária. O número de escovagens médias aos 6-9anos, 10-14anos e 15-16anos foi 1,37; 1,48 e 1,55 no sexo masculino, no caso de sexo feminino estes valores passam para 1,58; 1,80 e 1,89 respetivamente. Discussão: Os números registados no presente estudo são semelhantes aos do I Estudo Nacional de Prevalência da Cárie Dentária, onde se verificou percentagens de 33%, 27% e 18,9% para os escalões referentes aos 6 anos, 9 anos e 15 anos. Existe uma melhoria significativa em cada um destes escalões nos dois estudos seguintes realizados pela DGS. Em 2008 estas percentagens foram de 51%, 44% e 28%, respetivamente para cada um dos escalões. Em 2015 existiu apenas um pequeno acréscimo, com percentagens registadas de 54,8%, 53% e 32,4%, respetivamente. A última percentagem, de 32,4%, refere-se neste caso ao escalão dos 18 anos, uma vez que a DGS substituiu o escalão de estudo dos 15 anos de idade. Quando nos referimos ao número de escovagens médio, os números registados neste estudo têm uma evolução semelhante aos encontrados no III Estudo Nacional de Prevalência da Cárie Dentária, publicado em 2015 pela DGS, que refere que aos 6 anos 53% dos inquiridos escova duas vezes ao dia e 25,7% apenas uma vez, enquanto que aos 12 anos nos deparamos com uma descida para 19,9% dos que escovam 1x por dia e um aumento para 69,9% dos que escovam duas vezes. O mesmo estudo afirma ainda que as jovens escovam mais vezes os dentes, tal como no presente estudo. Conclusão: Os últimos anos têm-se revelado determinantes na melhoria da Saúde Oral dos portugueses e a aposta na prevenção, nomeadamente nos Cuidados Primários de Saúde Oral tem apresentado uma mais-valia inquestionável. Como em todos os percursos que se iniciam, a monitorização dos resultados e a sua melhoria contínua podem conduzir à otimização das estratégias e no seu conjunto contribuir para fazer ainda mais e melhor. Este estudo permitiu aferir, que a realidade, em contextos de Saúde Oral, no Concelho de Alijó é preocupante sugerindo que existem assimetrias em Portugal e cabe a todos os intervenientes em Saúde Oral diminuí-las. O envolvimento de cada Médico Dentista neste processo é fundamental.