[Temporomandibular joint disorder after dental treatment]. / TMD-klachten na een tandheelkundige behandeling.

A 56-year-old woman presented with persistent unilateral gnathological complaints after replacing an amalgam restoration. The patient reported tension and pain in the right side of her jaw, along with crackling sounds in the temporomandibular joint. Physical examination revealed tenderness in the right masseter muscle and temporomandibular joint, as well as anterior disc replacement with reduction on both sides. The initial treatment focused on providing rest to the temporomandibular joint, the Yoda exercise, and later, wet-needling. Despite initially limited improvement, the symptoms persisted. This case underscores the complexity and various treatment options for temporomandibular joint issues following dental procedures.

Health complaints before and at one and five years after removal of dental amalgam restorations - data from a prospective cohort study in Norway.

OBJECTIVE: Health complaints attributed to dental amalgam fillings comprise both intraoral and general health complaints. There are data suggesting that patients with medically unexplained physical symptoms (MUPS) attributed to amalgam fillings show improvement in symptoms after removal of all amalgam fillings. However, data indicating changes of specific health complaints are limited. This study evaluated the changes of health complaints after removal of amalgam restorations in patients with health complaints attributed to dental amalgam fillings. METHOD: Patients with MUPS attributed to dental amalgam (Amalgam cohort) had all their amalgam fillings removed. The participants indicated an intensity of 11 local and 12 general health complaints on numeric rating scales before the treatment and at follow-up after 1 and 5 years. The comparison groups comprising a group of healthy individuals and a group of patients with MUPS without symptom attribution to dental amalgam did not have their amalgam restorations removed. RESULTS: In the Amalgam cohort, mean symptom intensity was lower for all 23 health complaints at follow-up at 1 year compared to baseline. Statistically significant changes were observed for specific health complaints with effect sizes between 0.36 and 0.68. At the 5-year follow-up, the intensity of symptoms remained consistently lower compared to before the amalgam removal. In the comparison groups, no significant changes of intensity of symptoms of health complaints were observed. CONCLUSION: After removal of all amalgam restorations, both local and general health complaints were reduced. Since blinding of the treatment was not possible, specific and non-specific treatment effects cannot be separated.

Adverse reactions to dental biomaterials: Experiences from a specialty clinic.

OBJECTIVES: The Dental Biomaterials Adverse Reaction Unit was initiated by the Norwegian health authorities in 1992 as a response to the public concern regarding the safety of dental amalgam and other dental materials. In this paper, experiences from the Unit are briefly summarized. METHODS: The Norwegian health authorities' strategy included four main topics: (i) development of a manufacturer-independent system for monitoring adverse reactions related to dental materials, (ii) funding of a specialty unit for clinical examinations of referred patients, (iii) development of official guidelines for examination and treatment of patients with health complaints attributed to dental materials, and (iv) funding of an experimental treatment project for patients with health complaints attributed to dental amalgam. RESULTS: From the start, more than 2700 adverse reaction reports were received. In the initial years, amalgam was the most frequent material mentioned in the reports. Reports about polymer-based composite materials have not increased after the prohibition of amalgam in Norway. Clinical examination of referred patients is complex and time consuming, and it is important to consider differential diagnoses. There are methodological challenges associated with the design of experimental treatments used on patients with adverse reactions attributed to dental materials. However, the results from the treatment project indicate lower symptom load after replacement of amalgam with other dental restorative materials. SIGNIFICANCE: Producer independent adverse reaction reporting can provide valuable information about the safety of these materials and could serve as a complement to the mandatory reporting system described in the European medical device regulations (MDR).

Mast cells in oral lichen planus and oral lichenoid lesions related to dental amalgam contact.

The aim of this study was to analyze the expression of mast cell markers toluidine blue, c-kit, and tryptase and presence of mononuclear inflammatory cells in oral lichen planus (OLP) and oral lichenoid lesions related to dental amalgam. Nineteen specimens of OLP, OLLC, and healthy oral mucosa were selected. Mononuclear inflammatory cells were analyzed. Histochemical and immunohistochemical analyses were performed using toluidine blue, anti-c-kit and anti-tryptase reagents, and the results were quantified in areas A and B of connective tissue. Mast cells of all OLP and OLLC samples were positive for toluidine blue, c-kit, and tryptase. The density of toluidine blue+, c-kit+ and tryptase+ mast cells was higher in tissue with OLP and OLLC compared with healthy controls (p < 0.05). No difference was noted in mast cells density between OLP and OLLC (p > 0.05). The density of tryptase+ mast cells was higher in the subepithelial region (area A) than the region below it (Area B) in OLLC (p = 0.047). The mononuclear inflammatory cell density was higher in OLLC compared to OLP, but without statistical significance (p > 0.05). A positive statistical correlation was found between mononuclear immune cells and density of c-kit+ and tryptase+ mast cells in OLP (r = 0.943 and r = 0.886, respectively). Our data demonstrate that the etiopathogenesis process of OLP and OLLC modulates the expansion and degranulation of mast cells; mast cells density, however, was similar between OLP and OLLC. The distribution of mast cells appears to vary along the lamina propria.

Mercurial risk from dental amalgam use in a population of Moroccan dentists: A latent class regression approach.

BACKGROUND: Dentists using dental amalgam are chronically exposed to low doses of elemental mercury. The complex toxico-kinetics of this systemic toxicant results in polymorphic and variable clinical phenotypes. In this context, adapted statistical methods are required to highlight potential adverse effects of occupational mercury exposure on dentists' health. OBJECTIVE: The present study aims to analyze the distribution of self-reported subjective symptoms, commonly associated with chronic mercury poisoning, according to occupational mercury exposure in a population of Moroccan liberal dentists. METHODS: In order to achieve the defined objectives, a three-step latent class regression was fitted. First a latent class analysis was performed to cluster the studied population according to their declared symptoms. Dentists were then classified in the defined latent classes based on their posterior probabilities. Finally, a logistic regression is fitted to identify predictors associated with the latent classes' membership. RESULTS: The final obtained model showed acceptable calibration and discrimination. Its interpretation revealed that the increase of the frequency of amalgam use was associated with significant higher odds of belonging to the high risk latent class. CONCLUSIONS: The present study represents an initial step towards the development of diagnosis model that predict clinical profiles according to occupational mercury exposure.

Prevalence and mean number of teeth with amalgam and nonamalgam restorations, United States, 2015 through 2018.

BACKGROUND: Amalgam has been used for more than 150 years as a safe and reliable restorative material. The authors described the occurrence of amalgam and nonamalgam restorations in the United States in primary and permanent teeth across age groups and according to sociodemographic characteristics. METHODS: The authors used clinical examination data from the National Health and Nutrition Examination Survey 2015-2018 for participants 2 years and older (n = 17,040). The authors estimated the prevalence and mean number of amalgam and nonamalgam restorations in primary and permanent teeth according to age groups (2-5 years, 6-11 years, 12-15 years, 16-19 years, 20-39 years, 40-59 years, 60-79 years, and ≥ 80 years), race and ethnicity, federal poverty guideline, education, and pregnancy status. RESULTS: The prevalence of amalgam restorations ranged from 4% through 69%. Overall, amalgam restorations were more prevalent in children and adolescents from racial and ethnic minority groups and families at lower poverty levels and with lower education. The mean number of teeth with nonamalgam restorations was higher than those with amalgam restorations in primary teeth of children aged 6 through 11 years, permanent teeth of those 12 through 15 years and 20 through 39 years, and women aged 20 through 49 years, regardless of pregnancy status. The mean number of amalgam restorations was higher than that for nonamalgam restorations in older age groups. CONCLUSIONS: Nonamalgam restorations were the most common in the primary teeth of children older than 5 years and in the permanent teeth of adults younger than 40 years. Amalgam restorations were more common in older adults. Amalgam and nonamalgam restorations were equally common in children younger than 5 years. PRACTICAL IMPLICATIONS: The study findings suggest a shift from amalgam to alternative restorative materials in the United States.

The association of auditory function measures with low-level methylmercury from oceanic fish consumption and mercury vapor from amalgam: The Seychelles Child Development Study Nutrition 1 Cohort.

BACKGROUND: Some authors have reported that low-level exposure to methylmercury (MeHg) adversely impacts measures of auditory function. These reports, however, are not consistent in their findings. Consequently, we examined auditory function in a population exposed to low-level methylmercury (MeHg) exposure from fish consumption and to mercury vapor (Hg0) from dental amalgams. We analyzed their associations with the participants hearing acuity, absolute and interwave ABR latencies, and otoacoustic emissions (distortion product/DPOAE and click evoked/CEOAE). DESIGN: We administered an audiometry test battery to 246 participants from the Seychelles Child Development Study (SCDS) Nutrition Cohort 1 (NC1) at 9 years of age. The test battery included standard pure-tone audiometry, tympanometry, Auditory Brainstem Responses (ABR) and Distortion Product and Click Evoked Otoacoustic Emissions (DPOAE and CEOAE) testing. We measured prenatal MeHg exposure in maternal hair and postnatal MeHg in children's hair. We approximated prenatal Hg0 exposure using maternal amalgam surface area and postnatal Hg0 using children amalgam surface area. Complete exposure records and audiometric data were available on 210 participants and in them we analyzed the association of MeHg and Hg0 exposures with auditory outcomes using covariate-adjusted linear regression models adjusted for sex and tympanometric pressure. RESULTS: Hg exposures were similar for both sexes. Seven of the 210 evaluable participants examined had either a mild (5) or moderate (2) hearing loss. Four had a mild monaural hearing loss and 3 had either a mild (1) or moderate (2) bilateral hearing loss. No participant had greater than a moderate hearing loss in either ear. Hg exposures were higher in participants with either a mild or moderate hearing loss, but these differences were not statistically significant. Among the 210 with complete data, neither prenatal nor postnatal MeHg nor Hg0 exposure was statistically significantly associated with any of the ABR endpoints (p > 0.05 for all 72 associations). Neither prenatal nor postnatal Hg0 exposure was associated with any of the OAE endpoints (p > 0.05). MeHg exposure was statistically associated with 6 of the 56 DPOAE endpoints (p-values between 0.0001 and 0.023), but none of the 40 CEOAE endpoints. Two of the associations occurred with prenatal MeHg exposures and 1 of those would suggest a beneficial effect. Four of the other associations occurred with postnatal MeHg exposures with only 2 found in left ears of both males and females and the other 2 in the left and right ear of females at only one frequency. CONCLUSION: Overall, these data do not present a clear and consistent pattern to suggest that the auditory system is negatively affected by low-level methylmercury exposure due to dietary consumption of oceanic fish or mercury vapor exposure from dental amalgams.

Mercury, silver and selenium in serum before and after removal of amalgam restorations: results from a prospective cohort study in Norway.

OBJECTIVE: A prospective cohort study on changes of health complaints after removal of amalgam restorations was carried out at the request of the Norwegian Directorate of Health. The aim was to provide and evaluate experimental treatment to patients with health complaints attributed to dental amalgam fillings. METHODS: Patients (n = 32) with medically unexplained physical symptoms (MUPS), which were attributed to dental amalgam restorations had all their amalgam restorations removed and replaced with other dental restorative materials. Samples of blood were collected before and 1 year after removal of the fillings, and concentration of inorganic mercury (I-Hg), methylmercury (MeHg), silver (Ag) and selenium (Se) in serum was determined by inductively coupled plasma-sector field mass spectrometry. The comparison groups (one with MUPS but without attribution to amalgam [n = 28] and one group of healthy individuals [n = 19]) received no treatment. The participants responded to questionnaires at baseline and at follow-up after 1 and 5 years. RESULTS: Concentration of I-Hg and Ag in serum decreased significantly after removal of all amalgam restorations. Concentration of MeHg and Se in serum were not changed. Intensity of health complaints was significantly reduced after amalgam removal, but there were no statistically significant correlations between exposure indicators and health complaints. CONCLUSIONS: Removal of all amalgam restorations is followed by a decrease of concentration of I-Hg and Ag in serum. The results support the hypothesis that exposure to amalgam fillings causes an increase of the daily dose of both I-Hg and Ag. Even though intensity of health complaints decreased after removal of all amalgam restorations there was no clear evidence of a direct relationship between exposure and health complaints. Trial registration: The project is registered at Clinicaltrials.gov (NCT01682278).

Impact of dental restorations and removable prostheses on potentially malignant oral mucosal disorders in the general population.

STATEMENT OF PROBLEM: Dental restorations and removable dental prostheses have been considered as risk factors for potentially malignant disorders of the oral mucosa. It remains unclear whether amalgam, composite resins, and prosthesis materials can induce potentially malignant disorders. PURPOSE: The purpose of this clinical study was to determine the relationship between the presence of amalgam and composite resin restorations, crowns and fixed partial dentures, and removable prostheses in potentially malignant disorders. MATERIAL AND METHODS: The data of 6041 participants in the population-based Studies of Health in Pomerania (SHIP) were accessed. Potentially malignant disorders had been clinically diagnosed by calibrated dentists and documented with photographs. Dental treatment was subdivided into restored and replaced teeth. Dental restorations were subclassified as buccal composite resin or amalgam restorations. Prosthetic treatment was subclassified into removable partial or complete prostheses and definitive restorations with crowns and fixed partial dentures. RESULTS: In the maxilla, participants with removable prostheses had a higher incidence of potentially malignant disorders than participants not undergoing treatment with removable prostheses (OR 2.12; 95% CI: 1.08-4.18), but not in the mandible (OR 1.30; 95% CI: 0.67-2.53). The surfaces with composite resin restorations were associated with a slightly higher risk of mucosal lesions than those without the restorations (OR 1.04; 95% CI: 1.01-1.07). No significant association was found between amalgam restorations and mucosal lesions. CONCLUSIONS: Participants with removable prostheses have a higher risk of potentially malignant disorders. Composite resin restorations are associated with a higher risk of mucosal lesions, whereas no significant association was found between amalgam restorations and mucosal lesions.

Onset of oral lichen planus following dental treatments: A nested case-control study.

INTRODUCTION: The exposure to amalgam restorations has been reported to bring about altered immunity followed by inflammation and infection. AIMS: This study aimed at identifying whether patients who received restorative or endodontic treatments, or tooth extraction, would have altered odds of developing oral lichen planus (OLP). MATERIAL AND METHODS: In this population-based nested case-control study, 421 cases of OLP and 1,684 controls were included after propensity score matching. Logistic regression was used to estimate the adjusted odds ratio (aOR) of OLP in individuals who had received amalgam and composite resin restorations, root canal therapy, and tooth extraction over a follow-up duration of five years. RESULTS: There were no significantly different odds of OLP for those who underwent either amalgam (aOR = 0.948, 95% CI = 0.853-1.053, p = 0.3170) or resin restorations (aOR = 1.007, 95% CI = 0.978-1.037, p = 0.6557) in both anterior and posterior teeth in an observational period of five  years after restorations. Root canal therapy was associated with significantly lower odds of OLP, with each additional root canal therapy attenuating the risk of OLP at an aOR of 0.771 (95% CI = 0.680-0.874, p = 0.0001) for both anterior (aOR = 0.786, 95% CI = 0.626-0.986, p = 0.0372) and posterior teeth (aOR = 0.762, 95% CI = 0.650-0.893, p = 0.0008). Likewise, each tooth extraction reduced the risk of OLP, with an aOR of 0.846 (95% CI = 0.772-0.927, p = 0.0003), especially for anterior teeth (aOR = 0.733, 95% CI = 0.595-0.904, p = 0.0037). CONCLUSIONS: We reported no significant association between dental restorations and consequent OLP, and significantly lower odds of OLP following both root canal therapy and tooth extraction.

Dental material allergies and oral soft tissue reactions.

Dental materials can cause reactions to the oral mucosa and present to the general dental practitioner. These are often referred to as 'allergies' but are frequently lichenoid reactions. Most of these are related to dental amalgam restorations and can be remedied by replacing the restoration with another suitable material. Other metals, including gold, palladium, nickel and chrome, have also been reported to trigger mucosal changes. Less commonly, issues arise from other restorative materials, including denture acrylics, composites and glass polyalkenoates. Reactions are also reported due to endodontic and sealing materials. It is unclear what role skin 'patch' testing has in managing dental material allergies. This article aims to give the practitioner a clearer picture of dental material allergy issues and how they should be approached in primary dental practice.

Dental amalgam: the history and legacy you perhaps never knew?

Much has been written about dental amalgam. Over many years, it has served the profession well, yet on environmental grounds its use is being phased down. This article seeks to explore key milestones in the history and development of this versatile material, as well as highlighting how international standards have assisted in reducing environmental mercury contamination.

Is amalgam removal in patients with medically unexplained physical symptoms cost-effective? A prospective cohort and decision modelling study in Norway.

There are many patients in general practice with health complaints that cannot be medically explained. Some of these patients attribute their health complaints to dental amalgam restorations. This study examined the cost-effectiveness of the removal of amalgam restorations in patients with medically unexplained physical symptoms (MUPS) attributed to amalgam fillings compared to usual care, based on a prospective cohort study in Norway. Costs were determined using a micro-costing approach at the individual level. Health outcomes were documented at baseline and approximately two years later for both the intervention and the usual care using EQ-5D-5L. Quality adjusted life year (QALY) was used as a main outcome measure. A decision analytical model was developed to estimate the incremental cost-effectiveness of the intervention. Both probabilistic and one-way sensitivity analyses were conducted to assess the impact of uncertainty in costs and effectiveness. In patients who attribute health complaints to dental amalgam restorations and fulfil the inclusion and exclusion criteria, amalgam removal is associated with modest increase in costs at societal level as well as improved health outcomes. In the base-case analysis, the mean incremental cost per patient in the amalgam group was NOK 19 416 compared to the MUPS group, while mean incremental QALY was 0.119 with a time horizon of two years. Thus, the incremental costs per QALY of the intervention was NOK 162 680, which is usually considered cost effective in Norway. The estimated incremental cost per QALY decreased with increasing time horizon, and amalgam removal was found to be cost saving over both 5 and 10 years. This study provides insight into the costs and health outcomes associated with the removal of amalgam restorations in patients who attribute health complaints to dental amalgam fillings, which are appropriate instruments to inform health care priorities.

Biocompatibility of Amalgam vs Composite - A Review.

The Minamata Convention resulted in restrictions in the use of amalgam in daily dental practice. This opens up new discussions about the biocompatibility of amalgam, but also of composites as alternative materials. In the following review article, these issues will be discussed in more detail to provide dentists with a knowledge base for themselves and for communication with their patients. In addition to mercury in amalgam or monomers in composites, bisphenol A and nanoparticles generated during the grinding, polishing or removal of restorations must also be included in the biocompatibility evaluation. In laboratory tests, these substances cause toxic reactions, and bisphenol A also exhibits estrogen-like effects. However, it must be taken into account that the concentrations used in laboratory tests are much higher than in clinical practice. Thus, both amalgam and composite can be used in the general population. Nevertheless, for scientifically, politically and legally defined risk groups (e.g. dental personnel, allergic persons, pregnant or lactating women, children under 15 years of age, people with certain systemic diseases), indication restrictions and precautionary measures must be observed. The well-known amalgam discussion has taught us the importance of thorough and open risk communication with the patient.

Amalgam phase-out, an environmental safety concern: a cross-sectional study among general dental practitioners in Pakistan.

BACKGROUND: Amalgam has been the gold standard for restorations in posterior teeth. Mercury, a major component of dental amalgam, is considered an environmental pollutant. The Minamata Convention on mercury recomends a reduction in the use of mercury-containing products. Since Pakistan is a signatory to the Convention, the same amalgam phase-out limitations are implemented in Pakistan. AIMS: To identify and assess the use of amalgam and its waste management by dentists in Pakistan post-Minamata Convention guidelines. METHODS: A cross-sectional study was conducted in Lahore among 520 general dental practitioners in 2019. RESULTS: The sample size for the study was calculated as 500; the questionnaire was distributed among 550 dentists. Dental amalgam was used by only 41.6% of the dentists in their practice; 55.0% perceived it to be a health risk. Most of the dentists (76.3%) were unaware of the proper disposal protocols for dental amalgam and 76.5% were unaware of any guidelines regarding amalgam use and disposal. CONCLUSION: Although there is a gap in knowledge among the dentists regarding amalgam disposal, dentists in Pakistan are reducing their use of dental amalgam in accordance with the guidelines of the Minamata Convention.