Dental Amalgam Research Articles

Analysis of dental amalgam fillings on primary Sjögren's syndrome: A population-based case-control study in Taiwan.

Primary Sjören's syndrome (pSS) is an autoimmune disease characterized by the inflammatory infiltrate and progressive dysfunction of salivary glands. Dental amalgam with mercury has been raised the public concerns regarding its purported mercury toxicity from dental amalgam to possible systemic inflammatory and immune reactions.In this study, a nationwide population-based database was employed to investigate the association of amalgam filling (AMF) and the risk of pSS. A retrospective case-control study was sourced from the Taiwanese National Health Insurance Research Database (NHIRD) from 2000 to 2013. Case and control groups were matched by sex, age, urbanization level, monthly income, and comorbidities using the propensity score method with a 1:1 ratio. In this study, 5848 cases and 5848 controls were included.The results demonstrated no statistically significant differences between AMF and pSS (odds ratio [OR]: 0.974, 95% confidence interval [CI] = 0.904–1.049). In addition, pSS was also not associated with AMF for women (OR: 0.743, 95% CI = 0.552–1.000) and men (OR: 1.006, 95% CI = 0.670–1.509), respectively.Taken together, evidence demonstrated that the association of AMF and pSS was inconsistent from this robust register databank.

The Hazardous Effects of Dental Amalgam Fillings in Human Body: A Systematic Review

The Dental amalgam used in the dental fillings is basically an alloy of mercury (Hg). The amalgam is one of the most commonly used and versatile restorative material. Since more than 150 years this alloy of mercury, that is amalgam is used for it been economical, easy to use, durable, high strength and bacterio-static characteristics. Due to environmental pollution, detrimental health its use is decreasing in recent times. Also its not so appealing like the other materials used that resemble the tooth color. The tooth coloured restorative materials are recommended by both the doctor and the patient. Many researchers suggested that over the period of time the mercury from the filling might leach into the mouth. Thus in this study a detailed review of all the literature available online is done to understand the hazardous effects of dental amalgam fillings in the human body. The systematic literature search using Scopus, PubMed, EMBASE and Web of Science electronic databases was done using PRISMA. The experiments conducted in Sheep and monkey suggested the penetration of amalgam into the jaw bone of the patient with dental restorations. Constant exposure of mercury at lower levels can also lead to multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus. Most commonly reported renal dysfunction due to the dental amalgams are Tubular and Glomerular damage of the kidneys.

Biomedical waste management in dental practice and its significant environmental impact: A perspective

Biomedical waste (BMW) is an emerging occupational and environmental health hazard in the health care platform. BMW in any form generated from hospitals during diagnosis, surgery, management of patients, antibiotics, radioactive isotope needs proper handling and disposal. In the field of dentistry, mercury waste, waste from dental amalgam, lead, and silver-containing waste were often found and have severe risks for health and are also environmental hazards. This also has an impact and risk of airborne pathogens if its improperly handled and disposed of. All these contaminated waste-like syringes, needles, sharps, blood-soaked gauze, which leads to infections, must be properly disposed of in various color codes indicated for a certain category of biomedical waste as per the guidelines from the government for the disposal. This article throws light on the categories of biomedical waste and extensive literature review on the research performed, waste generated from dental Clinics and hospitals. Environmental audit guidelines in the health care sector and its importance, alternative waste handling methods like the robotic model, which is an artificial intelligence employed to handle biomedical waste at a large scale, are discussed. • Methods of disposal and Guidelines of handling healthcare waste. • Importance of Medical audits in health care organization. • Waste generated from dental office through Lead, Mercury, Amalgam, Plastic. • Dealing with Risk, Alternate methods of waste disposal. • Novel technologies, Artificial intelligence, Robotic models.

Should dental amalgams be used in dental training? The perspectives of dental academics at a university in South Africa

Dental amalgam has been used in dentistry for the last 150 years to restore posterior teeth. Concerns regarding the safety issues with amalgam due to its mercury content have lead to the introduction of composite dental material to restore posterior teeth. This has transformed the teaching and training trends of direct restorative materials for posterior teeth. This descriptive study aimed to gain insight into academic staff and clinical supervisors’ perceptions regarding the use of dental amalgams in the teaching of restorative dentistry. This study used a qualitative method of data collection. Two focus group discussions were conducted between March and May 2020. Seventeen participants were invited to participate. Fourteen responded and participated, yielding an 82% response rate. The data identified two major themes, viz. the challenges experienced with the teaching of dental amalgam and curriculum development recommendations. Clinical quota requirements, disposal of waste products, and occupational and environmental risks regarding mercury exposure were sub-themes. Some of the curriculum recommendations included the skills gained during cavity preparations, the training and quota requirements of dental materials, and teaching trends locally, nationally and internationally.This study revealed that dental amalgam is still an integral part of the restorative dentistry curriculum at the university. However, the teaching of resin composite now occupies more than fifty percent of the restorative dentistry curriculum. Academics and clinical supervisors show a greater affinity for the placement of composite restorations.

Alteração dimensional de uma liga de gálio versus amálgama de prata

The aim of this study was to evaluate the dimensional change of a gallium alloy in comparison with four dental amalgams. The results showed that the amalgams satisfied the nº 1 A.D.A. specification which allows 0 ± 20 µm/cm dimensional change. The same did not occur with the gallium alloy wich showed an expansion of 27,38 µm/cm.

Validity and responsiveness of GHC-index in patients with amalgam-attributed health complaints

Objective Many patients have medically unexplained physical symptoms (MUPS); some of them attribute their health complaints to dental amalgam fillings. The aim of this study was to assess the validity and responsiveness of General Health Complaints index (GHC-index) for measuring the symptom load in MUPS patients compared to the widely used symptom outcome measure, Giessen Subjective Complaints List (GBB-24). Methods Three outcome measures – GHC-index, GBB-24, and Munich Amalgam Scale (MAS) – were administered at baseline and 12 months after removal of all dental amalgam restorations. The validity and responsiveness of these symptom measures were tested against external anchors: bodily distress syndrome (BDS), SF-36 vitality, and visual analogue scale (VAS). We tested both convergent and known group validities. We also examined the predictive validity and responsiveness to changes for each instrument. Results All the main outcome measures showed evidence of convergent and known group validities. The GHC-index, GBB-24 and MAS were all able to detect the anticipated differences in BDS and Energy. But the GBB-24 was more efficient in discriminating the BDS compared with the GHC-index (relative efficiency: RE = 0.69; 95% CI: 0.41–0.96) and MAS (RE = 0.59; 95% CI: 0.32–0.86). Each main outcome variable revealed good predictive validity for vitality (standardized coefficient: b ≈ 0.71 and R 2 ≈ 0.50). Moderate to high sensitivity to change over time was demonstrated, with GHC-index performing better. Conclusion The GHC-index is a valid and responsive instrument for assessing symptom load in MUPS patients attributing their health complaints to amalgam fillings and undergoing amalgam removal.

Assessment of Artifacts Induced by Various Dental Restorative Materials on Cone-Beam Computed Tomography- An in vitro Study

Objectives: The aim of this study was to assess and compare quantitatively and qualitatively the artifacts induced by various commonly used dental restorative materials in different sections of CBCT image and to characterize the pattern of artifact. Material and Methods: Thirty dental plaster blocks, each with one of each of mandibular second premolar, first molar and second molar teeth with crowns aligned as in the natural dentition were scanned by CBCT device and analyzed using CS 3D imaging software, before and after the first molar was prepared and restored with dental amalgam, composite resin or glass ionomer cement (GIC), 10 plaster blocks being randomly selected for each restorative material. The reformatted axial, coronal and sagittal scans were then quantitatively assessed for artifact by two calibrated dento- maxillofacial radiologists by comparing the control and restored scans of each plaster block in a blinded manner and documented the slice numbers from which the image became diagnostic. Then, the slice numbers were converted into millimeters away from the restoration. Results: Paired t test, ANOVA and post hoc Tukey tests were used for statistical analyses. The level of significance was set at α = 5%. Depending on the extent, the majority of artifacts produced were as follows: Dental amalgam >Composite resin >GIC. The artifact was most extensive in the coronal section. Streaks and scatter artifacts, linear artifacts extending outward from tooth surface and hypodense halo were predominant. Conclusion: Different dental restorative materials cause various amounts of artifacts in different planes of projection of CBCT image due to differences in density and atomic number.

Gingival Microleakage of Dental Amalgam, Bulk Fill Composite Resin and Alkasite Based Composite Restorations in Class II Cavities

ABSTRACT Objectives: To evaluate and compare gingival microleakage in class II cavities restored with amalgam, bulk-fill composite, and the new alkasite based dental composite (Cention-N). Materials and Methods: Two independant Class II cavities were prepared in forty extracted human third molars. Each molar had a mesial cavity with gingival margin located 1 mm occlusal to the cemento-enamel junction (supra CEJ) and a distal cavity with gingival margin located 1 mm apical to the CEJ (sub CEJ). The prepared molars were randomly assigned to four groups(n=10) according to the restorative material used. Group 1; was restored with dental amalgam. Group 2; was restored with bulk fill dental composite. Group 3; was restored with alkasite based composite without bonding agent. Group 4; was restored with alkasite based composite with bonding agent. The teeth were then thermocycled and immersed in methylene blue solution for 24h. The teeth were mesiodistally sectioned and evaluated under a stereomicroscope at×10 magnification. Dye penetration scorings were recorded, and data were analyzed Kruskal Wallis followed by post-hoc Dunn’s test. Results: Dental amalgam showed the least microleakage and came to be better than the Cention-N and bulkfill dental composite. Microleakage for Cention-N without bonding agent was the highest of all. In terms of supra CEJ and sub CEJ microleakage; the difference for group 1and 3 was nonsignificant but was significant for group 2 and 4. Conclusions: Alkasite based dental composite with bonding agent in class II restorations are not significantly different from Bulk fill composites in terms of microleakage

Dental amalgam: a practical guide

Historically, dental amalgam is the world's most commonly used restorative material. Its use is declining due to patient and professional demand for tooth-coloured restorations that are adhesive and promote minimally invasive tooth preparation techniques. Significant reduction has also resulted from environmental concerns relating to dental amalgam's ~50% mercury content. This paper provides a comprehensive review of the status of dental amalgam including its advantages and disadvantages, amalgam safety, regulations and legislation and a comparison with alternative restorative materials. As the undergraduate teaching of amalgam procedures has progressively declined, this paper also provides an illustrated step-by-step revision guide to the materials, equipment and clinical techniques that will optimize the restoration of challenging, complex cavities, where amalgam is still considered by many to be the material of choice. CPD/Clinical Relevance: Amalgam remains an excellent restorative material for long-lasting restorations in large/complex cavities and where moisture control presents challenges.

Conventional glass-ionomer cements: a guide for practitioners

Glass-polyalkenoate cements, also known as glass-ionomer cements (GICs), are one of the most commonly used bio-interactive restorative dental materials, having been available since the 1970s. With the promotion of minimally invasive operative dentistry (MID), and the reduction in the use of dental amalgam worldwide, the popularity of these materials has grown significantly in recent years. This article outlines the basics and clinical importance of GIC material science, and provides an overview of their use in restorative dentistry.CPD/Clinical Relevance: GICs are versatile dental biomaterials that require correct case selection, material handling and placement technique to ensure optimal clinical success.

Can removal of amalgam restorations reduce health complaints in patients with medically unexplained physical symptoms?

Design Three groups of non-equivalent patients using a prospective cohort study design. Patients who credited their medically unexplained symptoms (MUPS) to their dental amalgam restorations (amalgam cohort) were compared to two other groups: patients with MUPS who did not credit their symptoms to amalgam (MUPS cohort) and those who recognised themselves as healthy (healthy cohort). All participants initially filled in a questionnaire (Q1) which included the primary outcome: General Health Complaints index (GHC-index). The SF-36 Physical and Mental Component Summary was also included as a secondary outcome. Other outcomes, including blood, were collected but results will be reported in other publications. Patients in the amalgam and MUPS cohorts were assessed by their general physician (GP) to ensure their complaints met the criteria for MUPS. The amalgam cohort then had their amalgams removed by their dentist and, one year later, filled in the questionnaire again (Q2). The MUPS and healthy cohorts completed the Q2 two years after the Q1.Cohort selection Recruitment information for the amalgam cohort was sent to all dentists and GPs in Norway, and advertised via the Directorate of Health website and the Norwegian Dental Association. Once potential participants were identified, they were required to be assessed by both a dentist and GP to declare that oral and systemic diseases were adequately treated. The risk of deterioration of dental and medical health through participation in the study was also disclosed. For the amalgam cohort, patients had to have at least one amalgam filling and attribute the presence of these restorations to unexplained health complaints which had been present for at least three months. Patients in the MUPS cohort were recruited by their GP. These patients also had to have had unexplained health complaints for at least three months; however, the key difference being they did not attribute these complaints to amalgams. The healthy cohort was primarily recruited via dentists taking part in the study and patients self-assessed as being healthy. Both the MUPS and healthy cohorts were recruited regardless of amalgam status.Data analysis Descriptive statistics presented continuous data, and categorical data were presented as frequencies. Differences between the cohorts were analysed with analysis of variance (ANOVA) with covariate adjustment. Potential predictors of the primary outcome variable were analysed using multivariate analysis.Results In the amalgam, MUPS and healthy cohorts, 32, 28 and 19 patients, respectively, completed participation in the study. The GHC-index significantly reduced (p <0.001) between Q1 and Q2 in the amalgam cohort but not in the other cohorts. The change in the GHC-index (change in score) was greater in the amalgam cohort compared to the MUPS cohort and this was statistically significant (p = 0.004), indicating a greater reduction in health complaints.Conclusions General health complaints in patients with MUPS, that attributed their symptoms to their dental amalgams, reduced after removal of dental amalgam restorations.

Neurodevelopmental outcomes in young children exposed to dental amalgam

Neurodevelopmental outcomes in young children exposed to dental amalgam

The evaluation of effectiveness of adhesive systems on dental amalgam restorations

Aim: The purpose of this study was to evaluate the effectiveness of different adhesive systems in amalgam restorations and their effects on microleakage.&#x0D; Methodology: In this study, 105 caries-free extracted human permanent molar teeth were used. Teeth were randomly assigned to five groups (n=21), and class I cavities were created on the surface of each tooth. The first was a control group to which no adhesive system was applied. Amalgam Liner (VOCO GmbH, Cuxhaven Germany) was applied to Group II, Clearfil SE-Bond (Kuraray Europe GmbH, Frankfurt Germany) was applied to Group III, Panavia F 2.0 (Kuraray Europe GmbH, Frankfurt Germany) was applied to Group IV, Amalgambond Plus (Parkell Inc.Edgewood, NY USA) was applied to Group V, and then amalgam (Tytin, Kerr, California USA) restorations were placed. After the polishing process, samples were subjected to thermocycling 1,000 times. Teeth were sectioned bucco-palatinally/lingually, and microleakage scores of the occlusal walls were evaluated under a stereomicroscope at 15X magnification by a standardized scale ranging from 0 to 4. One tooth was selected randomly from each group for SEM (Scanning Electron Microscope), and SEM LEO EVO 40 (LEO Ltd., Cambridge UK) photographs of amalgam-tooth hard tissue interfaces were also taken at different magnifications. The results of the microleakage tests were statistically analyzed by both the Kruskal-Wallis Test and the Mann Whitney U Test.&#x0D; Results: In terms of microleakage among groups, the differences that were determined were significant (p&lt;0.05). Microleakage within the control group was determined to be the highest, and statistically important differences were observed between the other groups. Group V (Amalgambond Plus) was determined to have the lowest microleakage scores.&#x0D; Conclusion: In prepared class I cavities, amalgam adhesive systems are effective in preventing occlusal microleakage but do not completely blocked it.&#x0D; &#x0D; How to cite this article: Ünal M, Atakul F. The evaluation of effectiveness of adhesive systems on dental amalgam restorations. Int Dent Res 2021;11(2):83-92. https://doi.org/10.5577/intdentres.2021.vol11.no2.5&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

HBM4EU-MOM: intervene to raise awareness to specific dietary recommendations and reduce prenatal exposure to mercury

BACKGROUND AND AIM: Mercury and its compounds are toxic and are among the substances of higher concern globally. Toxicity depends on mercury compounds, route of exposure and duration. The European population is mostly exposed to organic mercury (methylmercury) due to fish consumption; while exposure to inorganic and elemental mercury is largely associated with dental amalgams, accidental spills of elemental mercury and food produced in contaminated sites. Previous studies have shown that mercury levels in European population are higher in countries with higher fish consumption. However, because of the beneficial nutrients they provide, fish are an essential component of the human diet. In order to reduce exposure and avoid adverse health effects, it is extremely important to balance the risks and benefits of eating fish, especially in vulnerable groups such as pregnant women. Most European countries do not have official guidelines for the consumption of fish during pregnancy, and even if these guidelines exist, they are often not communicated to pregnant women in an appropriate way. As such, under the European Human Biomonitoring Initiative (HBM4EU) an intervention study – HBM4EU-MOM – is being developed in five European countries with high fish consumption (Cyprus, Greece, Iceland, Portugal, Spain) to help reduce prenatal exposure to mercury, while ensuring the nutritional benefits of fish by developing and raising awareness to specific recommendations for fish consumption during pregnancy. METHODS: This presentation will highlight the work already performed, including the harmonized development of the intervention and support materials to be implemented in the five countries. RESULTS:Preliminary results on the implementation of the developed intervention and its evaluation using Human Biomonitoring will also be presented. CONCLUSIONS:This study's results will support the definition of policies to protect human health in vulnerable populations. HBM4EU has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 733032. KEYWORDS: Heavy metals, Chemical exposures, Exposure assessment, Food/nutrition, Biomarkers of exposure, International collaboration

Cyanides, Isocyanides, and Hydrides of Zn, Cd and Hg from Metal Atom and HCN Reactions: Matrix Infrared Spectra and Electronic Structure Calculations.

Zinc and cadmium atoms from laser ablation of the metals and mercury atoms ablated from a dental amalgam target react with HCN in excess argon during deposition at 5 K to form the MCN and MNC molecules and CN radicals. UV irradiation decreases the higher energy ZnNC isomer in favor of the lower energy ZnCN product. Cadmium and mercury atoms produce analogous MCN primary molecules. Laser ablation of metals also produces plume radiation which initiates H‐atom detachment from HCN. The freed H atom can add to CN radical to produce the HNC isomer. The argon matrix also traps the higher energy but more intensely absorbing isocyanide molecules. Further reactions with H atoms generate HMCN and HMNC hydrides, which can be observed by virtue of their C−N stretches and intense M−H stretches. Computational modeling of IR spectra and relative energies guides the identification of reaction products by providing generally reliable frequency differences within the Zn, Cd and Hg family of products, and estimating isotopic shifts using to 13C and 15N isotopic substitution for comparison with experimental data.

Direct composite resin fillings versus amalgam fillings for permanent posterior teeth.

Direct composite resin fillings versus amalgam fillings for permanent posterior teeth.

Improvement of corrosion resistance and dimensional change of the high copper dental amalgam by Al2O3 additions.

the main goal of this present investigation is to study the effect of the (Al2O3) addition on corrosion resistance and dimensional change of the high copper dental amalgam. One alloy has been prepared via casting composed of silver (47%), tin (30%), copper (22%), and zinc (1%). (Al2O3) addition is added in distinct percentages of the (0.5, 1, 1.5, 2) wt.%. Specimens were prepared according to ADA specification No. 1. The specimens have been stored at 37±1 C° using a chamber prepared for this purpose. corrosion resistance improved with addition from 0.5% to 2% (Al2O3) and observed that dimensional change of amalgam improved after (Al2O3) additions.

Recent advances in dental composites

Composite resins are widely used aesthetic materials in restorative dentistry. These materials were introduced to overcome the inherent shortcomings of amalgam restorative materials. Dental amalgams are unesthetic and toxic. Earlier composites lack in mechanical properties to withstand the masticatory forces. Various filler particles have been added to composite resins to improve their physical and mechanical properties. Filled composite resins exhibit high compressive strength, abrasion resistance, ease of application and high translucency. Depending on the filler size and shapes, various composites have been developed until now. This article is a review of numerous types of composites that are technologically advanced to modify their properties.

Perceptions of dental therapy students regarding the teaching and training with dental amalgam, in a dental school in KwaZulu-Natal, South Africa

Dental amalgam has been used as a restorative material in dentistry for the past 150 years. This material has been used to restore posterior teeth throughout the world and is also used in South Africa. Dental amalgam has been the material of choice for patients presenting with large tooth decay areas, including the loss of cuspal areas. The reason for this is that dental amalgam was always considered strong and durable. Compared to alternate dental materials, this material could also withstand the significant forces associated with chewing and biting. Dental amalgam is also considered more cost-effective than alternate dental materials such as conventional glass ionomers, resin-modified glass ionomers, resin composite and ceramic restorations, making it more feasible and material of choice in lower economic countries, including South Africa.

Effect of universal adhesive on shear bond strength of metal bracket to enamel and dental amalgam

background: the bond strength of bracket to the tooth substrate is a critical matter. The different surface treatments are introduced to achieve an appropriate bond strength. We aimed to investigate the shear bond strength(SBS) of metal brackets to amalgam surfaces with universal adhesive and compared the results with the enamel group. Material and methods: in this in-vitro study, eighty specimens of amalgam in four groups and sixty specimens of the enamel in three groups were prepared. In amalgam groups, the control group was sandblasted and treated with transbond Xt whilst the other three groups prepared in the following order, group 2 sandblasted and treated with All Bond Universal(ABU), group 3 using diamond bur and ABU, and group 4 using self-etch mode of ABU. In enamel groups, control group was acid-etched and using transbond XT as a primer; in other two groups, the ABU was used as a primer in etched and self-etched mode. The specimens thermocycled and prepared for the SBS test. SEM analysis and ARI index were performed. pvalue≤ was considered significantly. Results: SBS of enamel was significantly higher than amalgam. Within enamel groups, etched with ABU showed the highest SBS. In amalgam group, the highest SBS was related to surface treated with ABU only, and the lowest SBS was related to diamond bur group. Conclusion: The etched surface of enamel showed the appropriate bond strength to bracket, and in the amalgam group, using mechanical preparation can decrease the oxide layer and compromise amalgam SBS. Keywords: Dental amalgam, Enamel, shear strength, Adhesive