Tribochemical silicoating of amalgam promotes effective amalgam-resin repairs.

The purpose of this study was to determine the most effective method for bonding composite resin to artificially aged amalgam. A spherical amalgam alloy was triturated and condensed by hand into cylindrical plastic molds (6 mm in diameter and 4 mm in height) to create 90 specimens, which were then aged for 2 weeks in closed plastic containers at 23°C. The amalgam surfaces underwent 1 of 3 surface treatments (n = 30 per treatment): (1) air particle abrasion (APA) with 50-µm aluminum oxide particles applied with a force of 45 psi from a 10-mm distance, followed by rinsing with deionized water for 60 seconds; (2) APA following the same protocol with subsequent application of a metal primer (Alloy Primer); or (3) coating with 30-µm silica (CoJet) at a force of 45 psi from a 10-mm distance until the surface turned black. Specimens were then treated with 1 of 3 adhesives (n = 10 per adhesive per surface treatment): (1) 2-step total-etch adhesive (OptiBond Solo Plus), (2) 1-step self-etching adhesive (Scotchbond Universal), or (3) dual-cured resin cement (Panavia F 2.0). Each adhesive was applied to the treated amalgam surfaces following its manufacturer's instructions. The specimens were placed in a bonding clamp, and nanocomposite resin columns, 2.38 mm in diameter and 2.00 mm in height, were photocured (40 seconds, 500 mW/cm2) against the treated amalgam surfaces. The specimens were stored for 24 hours in 37°C deionized water and underwent shear bond strength testing at a crosshead speed of 0.5 mm/min. Data were analyzed using 2-way analysis of variance and post hoc analysis with the Tukey test at 95% confidence. The mean (SD) shear bond strength values ranged from 12.3 (1.2) MPa for aluminum oxide-treated surfaces bonded with OptiBond Solo Plus to 25.9 (4.6) MPa for silicoated surfaces bonded with Panavia F 2.0. All bonding agents produced the highest shear bond strength when the amalgam surface was silicoated. These results indicate that composite can be effectively bonded to amalgam via silicoating.

Evaluation of the reasons for failure in teeth with vital amputation treatment.

AIM: This study aims to evaluate the primary teeth undergoing amputation due to dental caries or trauma clinically and radiologically. MATERIAL AND METHODS: The amputation treatment of 90 primary teeth of 58 patients (Female: 20, Male: 38) aged 4-11 years was evaluated clinically and radiologically. Calcium Hydroxide was used for amputation in this study. Composite or amalgam was preferred as filling material in the same session of the patients. Clinical/radiological (Periapical/Panoramic X-ray) examination was performed on the teeth that were unsuccessful in treatment, on the day of the patient's complaint, and at the end of 1 year in the others. RESULTS: According to the clinical and radiological findings of the patients, 14.4% of the boys and 12.3% of the girls were unsuccessful. Amputation in male was a need in the 6-7 age group with a rate of 44.6% at most. Amputation in females was a need in the 8-9 age group with a rate of 52% at most. CONCLUSION: Success in amputation treatment depends on the tooth, the dentist, and the dental material applied.

The impact of different dental restorations on detection of proximal caries by cone beam computed tomography.

OBJECTIVES: To evaluate the effects of different types of restorations on observer ability to detect proximal caries in CBCT images. MATERIALS AND METHODS: Forty human premolars and molars with artificial proximal caries were placed proximal and distal to 5 molars having different restorations (amalgam, composite, resin-modified glass ionomer cement (RMGIC) fillings, zirconia, and lithium disilicate crowns) and a non-restored molar. CBCT scans were obtained using i-CAT® Next Generation. Images were rated twice by 2 observers. The exact depth of artificial caries was histologically established. Sensitivity, specificity, and area under the receiver operating characteristic curve (Az) values were calculated. RESULTS: Caries detection in teeth surfaces mesial and distal to amalgam showed compromised specificity and accuracy. Moreover, caries detection in teeth surfaces mesial to zirconia crown showed low sensitivity, specificity, and accuracy. Capability of CBCT in detection of proximal caries in teeth adjacent to composite, RMGIC, and lithium disilicate was comparable to those adjacent to non-restored molar. CONCLUSIONS: CBCT scans performed for tasks other than caries detection should be assessed for proximal caries in absence of any restorations as well as in presence of composite, RMGIC fillings, and lithium disilicate crowns. However, CBCT should not be used for proximal caries detection in teeth adjacent to amalgam and teeth surfaces mesial to zirconia crowns. CLINICAL SIGNIFICANCE: It is important to investigate the influence of artifacts produced by various restorations on CBCT-based caries detection to optimize CBCT benefits, caries diagnosis and avoid unnecessary treatment of sound surfaces.

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

BACKGROUND: Traditionally, amalgam has been used for filling cavities in posterior teeth, and it continues to be the restorative material of choice in some low- and middle-income countries due to its effectiveness and relatively low cost. However, there are concerns over the use of amalgam restorations (fillings) with regard to mercury release in the body and the environmental impact of mercury disposal. Dental composite resin materials are an aesthetic alternative to amalgam, and their mechanical properties have developed sufficiently to make them suitable for restoring posterior teeth. Nevertheless, composite resin materials may have potential for toxicity to human health and the environment. The United Nations Environment Programme has established the Minamata Convention on Mercury, which is an international treaty that aims "to protect the [sic] human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds". It entered into force in August 2017, and as of February 2021 had been ratified by 127 governments. Ratification involves committing to the adoption of at least two of nine proposed measures to phase down the use of mercury, including amalgam in dentistry. In light of this, we have updated a review originally published in 2014, expanding the scope of the review by undertaking an additional search for harms outcomes. Our review synthesises the results of studies that evaluate the long-term effectiveness and safety of amalgam versus composite resin restorations, and evaluates the level of certainty we can have in that evidence. OBJECTIVES: To examine the effects (i.e. efficacy and safety) of direct composite resin fillings versus amalgam fillings. SEARCH METHODS: An information specialist searched five bibliographic databases up to 16 February 2021 and used additional search methods to identify published, unpublished and ongoing studies SELECTION CRITERIA: To assess efficacy, we included randomised controlled trials (RCTs) comparing dental composite resin with amalgam restorations in permanent posterior teeth that assessed restoration failure or survival at follow-up of at least three years. To assess safety, we sought non-randomised studies in addition to RCTs that directly compared composite resin and amalgam restorative materials and measured toxicity, sensitivity, allergy, or injury. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included a total of eight studies in this updated review, all of which were RCTs. Two studies used a parallel-group design, and six used a split-mouth design. We judged all of the included studies to be at high risk of bias due to lack of blinding and issues related to unit of analysis. We identified one new trial since the previous version of this review (2014), as well as eight additional papers that assessed safety, all of which related to the two parallel-group studies that were already included in the review. For our primary meta-analyses, we combined data from the two parallel-group trials, which involved 1645 composite restorations and 1365 amalgam restorations in 921 children. We found low-certainty evidence that composite resin restorations had almost double the risk of failure compared to amalgam restorations (risk ratio (RR) 1.89, 95% confidence interval (CI) 1.52 to 2.35; P < 0.001), and were at much higher risk of secondary caries (RR 2.14, 95% CI 1.67 to 2.74; P < 0.001). We found low-certainty evidence that composite resin restorations were not more likely to result in restoration fracture (RR 0.87, 95% CI 0.46 to 1.64; P = 0.66). Six trials used a split-mouth design. We considered these studies separately, as their reliability was compromised due to poor reporting, unit of analysis errors, and variability in methods and findings. Subgroup analysis showed that the findings were consistent with the results of the parallel-group studies. Three trials investigated possible harms of dental restorations. Higher urinary mercury levels were reported amongst children with amalgam restorations in two trials, but the levels were lower than what is known to be toxic. Some differences between amalgam and composite resin groups were observed on certain measures of renal, neuropsychological, and psychosocial function, physical development, and postoperative sensitivity; however, no consistent or clinically important harms were found. We considered that the vast number of comparisons made false-positive results likely. There was no evidence of differences between the amalgam and composite resin groups in neurological symptoms, immune function, and urinary porphyrin excretion. The evidence is of very low certainty, with most harms outcomes reported in only one trial. AUTHORS' CONCLUSIONS: Low-certainty evidence suggests that composite resin restorations may have almost double the failure rate of amalgam restorations. The risk of restoration fracture does not seem to be higher with composite resin restorations, but there is a much higher risk of developing secondary caries. Very low-certainty evidence suggests that there may be no clinically important differences in the safety profile of amalgam compared with composite resin dental restorations. This review supports the utility of amalgam restorations, and the results may be particularly useful in parts of the world where amalgam is still the material of choice to restore posterior teeth with proximal caries. Of note, however, is that composite resin materials have undergone important improvements in the years since the trials informing the primary analyses for this review were conducted. The global phase-down of dental amalgam via the Minamata Convention on Mercury is an important consideration when deciding between amalgam and composite resin dental materials. The choice of which dental material to use will depend on shared decision-making between dental providers and patients in the clinic setting, and local directives and protocols.

Assessing the perceived impact of post Minamata amalgam phase down on oral health inequalities: a mixed-methods investigation.

BACKGROUND: Data from countries that have implemented a complete phase out of dental amalgam following the Minamata agreement suggest increased costs and time related to the placement of alternatives with consumers absorbing the additional costs. This aim of this study was to investigate the impact of a complete phase out of dental amalgam on oral health inequalities in particular for countries dependent on state run oral health services. METHODS: A mixed methods component design quantitative and qualitative study in the United Kingdom. The quantitative study involved acquisition and analysis of datasets from NHS Scotland to compare trends in placement of dental amalgam and a survey of GDPs in Yorkshire, UK. The qualitative study involved analysis of the free text of the survey and a supplementary secondary analysis of semi-structured interviews and focus groups with GDPs (private and NHS), dental school teaching leads and NHS dental commissioners to understand the impact of amalgam phase down on oral health inequalities. RESULTS: Time-trends for amalgam placement showed that there was a significant (p < 0.05) reduction in amalgam use compared with composites and glass ionomers. However dental amalgam still represented a large proportion (42%) of the restorations (circa 1.8 million) placed in the 2016-2017 financial year. Survey respondents suggest that direct impacts of a phase down were related to increased costs and time to place alternative restorations and reduced quality of care. This in turn would lead to increased tooth extractions, reduced access to care and privatisation of dental services with the greatest impact on deprived populations. CONCLUSION: Amalgam is still a widely placed material in state run oral health services. The complete phase down of dental amalgam poses a threat to such services and threatens to widen oral health inequalities. Our data suggest that a complete phase out is not currently feasible unless appropriate measures are in place to ensure cheaper, long-lasting and easy to use alternatives are available and can be readily adopted by primary care oral health providers.

[Paradigm shift in conservative dentistry: the end of the amalgam era]. / Paradigmaváltás a fogmegtartó kezelésben: az amalgámkorszak vége.

Dental amalgam has been used for more than 150 years due to its beneficial mechanical properties and durability in dentistry. In the past and to date, many questions about amalgam restorations have arisen, especially regarding the mercury content, which has been the subject of global disputes. By presenting the past and present of the 'amalgam issue', the aim of our paper is to display the current position of international literature. This summary is based on the publications in the PubMed database, the guidelines of the Council of European Dentists. Although the use of dental amalgam is widespread, concerns have been raised about the adverse effect on human health and the environment, focusing on its heavy metal pollution during waste treatment. In 2017, the European Union (EU) adopted the so-called Mercury Regulation, based on the United Nations Minamata Convention on Mercury, the recommendations of which are presented in the present review. This Regulation includes the requirement for EU Member States to develop a national action plan for the phase-down of amalgam. The feasibility plan for complete phase-out may be guaranteed by 2030. The authors discuss the advantages and disadvantages of possible amalgam alternatives by presenting glass-ionomers and resin-based composites. In the future, more material research programmes and long-term follow-up studies are necessary. In addition to several global health organizations, the Council of European Dentists also draws attention to prevent dental caries, expecting to reduce the number of restorations. Orv Hetil. 2018; 159(42): 1700-1709.

Failure rate of single-unit restorations on posterior vital teeth: A systematic review.

STATEMENT OF PROBLEM: No knowledge synthesis exists concerning when to use a direct restoration versus a complete-coverage indirect restoration in posterior vital teeth. PURPOSE: The purpose of this systematic review was to identify the failure rate of conventional single-unit tooth-supported restorations in posterior permanent vital teeth as a function of remaining tooth structure. MATERIAL AND METHODS: Four databases were searched electronically, and 8 selected journals were searched manually up to February 2015. Clinical studies of tooth-supported single-unit restorative treatments with a mean follow-up period of at least 3 years were selected. The outcome measured was the restorations' clinical or radiological failure. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, the Cochrane Collaboration procedures for randomized control trials, the Strengthening the Reporting of Observational Studies in Epidemiology criteria for observational studies, 2 reviewers independently applied eligibility criteria, extracted data, and assessed the quality of the evidence of the included studies using the American Association of Critical Care Nurses' system. The weighted-mean group 5-year failure rates of the restorations were reported according to the type of treatment and remaining tooth structure. A metaregression model was used to assess the correlation between the number of remaining tooth walls and the weighted-mean 5-year failure rates. RESULTS: Five randomized controlled trials and 9 observational studies were included and their quality ranged from low to moderate. These studies included a total of 358 crowns, 4804 composite resins, and 303582 amalgams. Data obtained from the randomized controlled trials showed that, regardless of the amount of remaining tooth structure, amalgams presented better outcomes than composite resins. Furthermore, in teeth with fewer than 2 remaining walls, high-quality observational studies demonstrated that crowns were better than amalgams. A clear inverse correlation was found between the amount of remaining tooth structure and restoration failure. CONCLUSIONS: Insufficient high-quality data are available to support one restorative treatment or material over another for the restoration of vital posterior teeth. However, the current evidence suggests that the failure rates of treatments may depend on the amount of remaining tooth structure and types of treatment.

[The dependence of the marginal adaptation of composite fillings in caries cavities of class ii by black, on the state of oral hygiene and intensity of caries].

INTRODUCTION: The problem of treatment of dental caries by fillings in dentistry is the key point in dentistry. Thus the main issue is the long-term functioning of the restorations. Particularly acute, this problem in the reduction of cavities class II according to Black, where the pressure on the filling is sufficiently high. MATERIALS AND METHODS: It was examined and treated 87 patients with different levels of oral hygiene of oral cavity and caries of varying intensity and whom 186 defects of hard tissues of teeth class II Black were fitted. All patients were divided into 3 groups depending on the type of filling material selected. Each group was in turn divided into two groups depending on the type of the prepared cavity. In a subgroup (1) the preparation was carried out without additional primary cavity retention elements. In a subgroup (2) the preparation was carried out with the main cavity in the form of retention elements as extra place on the chewing surface. RESULTS: Analyzing the quality of edge adjacent of fillings and restorations in the long-term period (24 months) depending on the intensity of caries and oral hygiene, we found that the best results were obtained in patients with low intensity of caries, and in patients with a high level of oral hygiene of patients in all study groups. CONCLUSION: The best results in the short and long-term periods were obtained in II and IІІ groups. It should be noted that these groups the particularity of preparation has no influence on the quality of the restoration. According to restorations of group I where the restorative material was composite material as chemical hardening"Charisma PPF" ( "Heraeus Kulser"), this relation takes place. The best results in the short and long-term periods shown those restorations, under which created at preparing retention elements in the form of extra place.

Adhesively bonded versus non-bonded amalgam restorations for dental caries.

BACKGROUND: Dental caries (tooth decay) is one of the commonest diseases which afflicts mankind, and has been estimated to affect up to 80% of people in high-income countries. Caries adversely affects and progressively destroys the tissues of the tooth, including the dental pulp (nerve), leaving teeth unsightly, weakened and with impaired function. The treatment of lesions of dental caries, which are progressing through dentine and have caused the formation of a cavity, involves the provision of dental restorations (fillings). This review updates the previous version published in 2009. OBJECTIVES: To assess the effects of adhesive bonding on the in-service performance and longevity of dental amalgam restorations. SEARCH METHODS: We searched the Cochrane Oral Health Group Trials Register (to 21 January 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015, Issue 12), MEDLINE via Ovid (1946 to 21 January 2016) and EMBASE via Ovid (1980 to 21 January 2016). We also searched the US National Institutes of Health Trials Registry (http://clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (www.who.int/ictrp/search/en) (both to 21 January 2016) for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Randomised controlled trials comparing adhesively bonded versus traditional non-bonded amalgam restorations in conventional preparations utilising deliberate retention, in adults with permanent molar and premolar teeth suitable for Class I and II amalgam restorations only. DATA COLLECTION AND ANALYSIS: Two review authors independently screened papers, extracted trial details and assessed the risk of bias in the included study. MAIN RESULTS: One trial with 31 patients who received 113 restorations was included. At two years, 50 out of 53 restorations in the non-bonded group survived, and 55 of 60 bonded restorations survived with five unaccounted for at follow-up. Post-insertion sensitivity was not significantly different (P > 0.05) at baseline or two-year follow-up. No fractures of tooth tissue were reported and there was no significant difference between the groups or matched pairs of restorations in their marginal adaptation (P > 0.05). AUTHORS' CONCLUSIONS: There is no evidence to either claim or refute a difference in survival between bonded and non-bonded amalgam restorations. This review only found one under-reported trial. This trial did not find any significant difference in the in-service performance of moderately sized adhesively bonded amalgam restorations, in terms of their survival rate and marginal integrity, in comparison to non-bonded amalgam restorations over a two-year period. In view of the lack of evidence on the additional benefit of adhesively bonding amalgam in comparison with non-bonded amalgam, it is important that clinicians are mindful of the additional costs that may be incurred.

Materials for retrograde filling in root canal therapy.

BACKGROUND: Root canal therapy is a sequence of treatments involving root canal cleaning, shaping, decontamination and obturation. It is conventionally performed through a hole drilled into the crown of the affected tooth, namely orthograde root canal therapy. For teeth that cannot be treated with orthograde root canal therapy, or for which it has failed, retrograde root filling, which seals the root canal from the root apex, is a good alternative. Many materials, such as amalgam, zinc oxide eugenol and mineral trioxide aggregate (MTA), are generally used. Since none meets all the criteria an ideal material should possess, selecting the most efficacious material is of utmost importance. OBJECTIVES: To determine the effects of different materials used for retrograde filling in children and adults for whom retrograde filling is necessary in order to save the tooth. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 13 September 2016); the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8) in the Cochrane Library (searched 13 September 2016); MEDLINE Ovid (1946 to 13 September 2016); Embase Ovid (1980 to 13 September 2016); LILACS BIREME Virtual Health Library (1982 to 13 September 2016); and OpenSIGLE (1980 to 2005). ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. We also searched Chinese BioMedical Literature Database (in Chinese, 1978 to 20 September 2016); VIP (in Chinese, 1989 to 20 September 2016); China National Knowledge Infrastructure (in Chinese, 1994 to 20 September 2016); and Sciencepaper Online (in Chinese, to 20 September 2016). No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: We selected randomised controlled trials (RCTs) only that compared different retrograde filling materials, with reported success rate that was assessed by clinical or radiological methods for which the follow-up period was at least 12 months. DATA COLLECTION AND ANALYSIS: Two review authors extracted data independently and in duplicate. Original trial authors were contacted for any missing information. Two review authors independently carried out risk of bias assessments for each eligible study following Cochrane methodological guidelines. MAIN RESULTS: We included six studies (916 participants with 988 teeth) reported in English. All the studies had high risk of bias. The six studies examined five different comparisons, including MTA versus intermediate restorative material (IRM), MTA versus super ethoxybenzoic acid cement (Super-EBA), Super-EBA versus IRM, dentine-bonded resin composite versus glass ionomer cement and glass ionomer cement versus amalgam. There was therefore little pooling of data and very little evidence for each comparison.There is weak evidence of little or no difference between MTA and IRM at the first year of follow-up (risk ratio (RR) 1.09; 95% confidence interval (CI): 0.97 to 1.22; 222 teeth; quality of evidence: low). Insufficient evidence of a difference between MTA and IRM on success rate at the second year of follow-up (RR 1.06; 95% CI: 0.89 to 1.25; 86 teeth, 86 participants; quality of evidence: very low). All the other outcomes were based on a single study. There is insufficient evidence of any difference between MTA and Super-EBA at the one-year follow-up (RR 1.03; 95% CI: 0.96 to 1.10; 192 teeth, 192 participants; quality of evidence: very low), and only weak evidence indicating there might be a small increase in success rate at the one-year follow-up in favour of IRM compared to Super-EBA (RR 0.90; 95% CI: 0.80 to 1.01; 194 teeth; quality of evidence: very low). There was also insufficient and weak evidence to show that dentine-bonded resin composite might be a better choice for increasing retrograde filling success rate compared to glass ionomer cement at the one-year follow-up (RR 2.39; 95% CI: 1.60 to 3.59; 122 teeth, 122 participants; quality of evidence: very low). And there was insufficient evidence of a difference between glass ionomer cement and amalgam at both the one-year (RR 0.98; 95% CI: 0.86 to 1.12; 105 teeth; quality of evidence: very low) and five-year follow-ups (RR 1.00; 95% CI: 0.84 to 1.20; 82 teeth; quality of evidence: very low).None of these studies reported an adverse event. AUTHORS' CONCLUSIONS: Based on the present limited evidence, there is insufficient evidence to draw any conclusion as to the benefits of any one material over another. We conclude that more high-quality RCTs are required.

WITHDRAWN: Dental fillings for the treatment of caries in the primary dentition.

BACKGROUND: Childhood caries (tooth decay) consists of a form of tooth decay that affects the milk teeth (also known as baby or primary teeth) of children. This may range from tooth decay in a single tooth to rampant caries affecting all the teeth in the mouth. Primary teeth in young children are vital to their development and every effort should be made to retain these teeth for as long as is possible. Dental fillings or restorations have been used as an intervention to repair these damaged teeth. Oral health professionals need to make astute decisions about the type of restorative (filling) material they choose to best manage their patients with childhood caries. This decision is by no means an easy one as remarkable advances in dental restorative materials over the last 10 years has seen the introduction of a multitude of different filling materials claiming to provide the best performance in terms of durability, aesthetics, symptom relief, etc when placed in the mouth. This review sought to compare the different types of dental materials against each other for the same outcomes. OBJECTIVES: The objective of this review was to compare the outcomes (including pain relief, survival and aesthetics) for restorative materials used to treat caries in the primary dentition in children.  Additionally, the restoration of teeth was compared with extraction and no treatment. SEARCH METHODS: Electronic searches of the following databases were undertaken: the Cochrane Oral Health Group's Trials Register (up to January 2009); CENTRAL (The Cochrane Library 2009, Issue1); MEDLINE (1966 to January 2009); EMBASE (1996 to January 2009); SIGLE (1976 to 2004); and conference proceedings on early childhood caries, restorative materials for paediatric dentistry, and material sciences conferences for dental materials used for children's dentistry (1990 to 2008). The searches attempted to identify all relevant studies irrespective of language.Additionally, the reference lists from articles of eligible papers were searched, handsearching of key journals was undertaken, and personal communication with authors and manufacturers of dental materials was initiated to increase the pool of suitable trials (both published and unpublished) for inclusion into this review. SELECTION CRITERIA: Randomised controlled trials (RCTs) or quasi-randomised controlled trials with a minimum period of 6 months follow up were included. Both parallel group and split-mouth study designs were considered. The unit of randomisation could be the individual, group (school, school class, etc), tooth or tooth pair. Included studies had a drop-out rate of less than 30%. The eligible trials consisted of young children (children less than 12 years) with tooth decay involving at least one tooth in the primary dentition which was symptomatic or symptom free at the start of the study. DATA COLLECTION AND ANALYSIS: Data were independently extracted, in duplicate, by two review authors. Disagreements were resolved by consultation with a third review author. Authors were contacted for missing or unclear information regarding randomisation, allocation sequence, presentation of data, etc. A quality assessment of included trials was undertaken. The Cochrane Collaboration statistical guidelines were followed for data analysis. MAIN RESULTS: Only three studies were included in this review. The Fuks 1999 study assessed the clinical performance of aesthetic crowns versus conventional stainless steel crowns in 11 children who had at least two mandibular primary molars that required a crown restoration. The outcomes assessed at 6 months included gingival health (odds ratio (OR) 0.3; 95% confidence interval (CI) 0.01 to 8.32), restoration failure (OR 3.29; 95% CI 0.12 to 89.81), occlusion, proximal contact and marginal integrity. The odds ratios for occlusion, proximal contact and marginal integrity could not be estimated as no events were recorded at the 6-month evaluation. The Donly 1999 split-mouth study compared a resin-modified glass ionomer (Vitremer) with amalgam over a 36-month period. Forty pairs of Class II restorations were placed in 40 patients (21 males; 19 females; mean age 8 years +/- 1.17; age range 6 to 9 years). Although the study period was 3 years (36 months), only the 6- and 12-month results are reported due to the loss to follow up of patients being greater than 30% for the 24- and 36-month data. Marks 1999a recruited 30 patients (age range 4 to 9 years; mean age 6.7 years, standard deviation 2.3) with one pair of primary molars that required a Class II restoration. The materials tested were Dyract (compomer) and Tytin (amalgam). Loss to follow up at 24 and 36 months was 20% and 43% respectively. This meant that only the 24-month data were useable. For all of the outcomes compared in all three studies, there were no significant differences in clinical performance between the materials tested.No studies were found that compared restorations versus extractions or no treatment as an intervention in children with childhood caries. AUTHORS' CONCLUSIONS: It was disappointing that only three trials that compared three different types of materials were suitable for inclusion into this review. There were no significant differences found in all three trials for all of the outcomes assessed. Well designed, randomised controlled trials comparing the different types of filling materials for similar outcomes are urgently needed in dentistry. There was insufficient evidence from the three included trials to make any recommendations about which filling material to use.

Sarcoidosis and Autoimmunity: From Genetic Background to Environmental Factors.

Sarcoidosis is a chronic multisystem disease with variable course resulting from the interaction between environmental factors and the immune system of individuals genetically predisposed. The evidence linking sarcoidosis with environmental triggers such as metals is increasing. We describe the case of a 44 year old female with a history. of smoking since age 30 and previous mercury dental filling who presented at physical examination with numerous subcutaneous nodules. Laboratory data showed accelerated erythrocyte sedimentation rate and high titer of anti-U1 ribonucleoprotein antibodies (U1 RNP). Skin biopsy and chest X-ray suggested the diagnosis of sarcoidosis. In this report we illustrate the different causes involved in the onset of sarcoidosis.

Twelve-year survival of 2-surface composite resin and amalgam premolar restorations placed by dental students.

STATEMENT OF PROBLEM: Composite resin and amalgam restorations are indicated for the restoration of posterior teeth. With increased esthetic demands, long-term clinical studies are required to evaluate the restorative success and reasons for failure of these materials. PURPOSE: The purpose of this retrospective study was to determine the survival and reasons for failure of directly placed 2-surface composite resin restorations and directly placed 2-surface amalgam restorations on premolars placed by Canadian dental students. MATERIAL AND METHODS: Using The University of Manitoba's dental management software and paper charts, all 2-surface composite resin and 2-surface amalgam restorations placed on premolars between January 1, 2002, and May 30, 2014, were included. Short-term failure (within 2 years), long-term failure, and reasons for failure were collected. A Kaplan-Meier survival estimate with an associated P value comparing composite resin to amalgam restoration curves was performed using SPSS statistical software. RESULTS: Over 12 years, 1695 composite resin and 1125 amalgam 2-surface premolar restorations were placed. Of these restorations, 134 composite resins (7.9%) and 66 amalgams (5.9%) failed. Short-term failures (2 years or less) consisted of 57 composite resin (4%) and 23 amalgam (2.3%) restorations. Long-term failures (greater than 2 years) consisted of 77 composite resin (4.5%) and 43 amalgam (3.8%) restorations. After 12 years of service, the survival probability of composite resin restorations was 86% and that of amalgam restorations 91.5%. The differences in composite resin and amalgam survival curves were also found to be statistically significant (P=.009 for Log-rank test). The main reasons for failure were recurrent caries and fracture of the tooth being restored. CONCLUSIONS: Within the limitations of this study, both composite resin and amalgam restorations had acceptable success rates and similar failure modes. Recurrent caries was still the most common reason for failure.

A study on the survival of primary molars with intact and with defective restorations.

BACKGROUND: Failed restorations in primary teeth are not always re-restored. Is re-restoration not required anymore? OBJECTIVE: To compare survival rates of primary molars with intact and defective amalgam and ART restorations. METHODS: A total of 649 restored primary molars, of which 162 were assessed with defective restorations for mechanical reasons, from a cluster-randomised controlled clinical trial, were followed up over a period of 3.5 years. Restored primary molars, extracted because of dental sepsis or toothache, were considered a failure. Primary molars with defective restorations were followed up from the time they were assessed defective. Data were analysed using PHREG model with frailty correction, Wald test, t-test, and jackknife procedure. RESULTS: The survival rate of primary molars with intact restorations (96.3%) was statistically significantly higher than that of primary molars with defective restorations (75.9%) over a 3-year period (P < 0.0001). Neither the effect of treatment protocol (amalgam or ART) (P = 0.05) nor the type of surface (single or multiple) (P = 0.73) was observed with respect to the survival rate of restored primary molars. CONCLUSIONS: Survival rates for primary molars with intact and defective amalgam and ART restorations were high. The 3-year survival rate of primary molars with intact restorations was significantly higher than that of primary molars with defective restorations.

Success rates of manual restorative treatment (MRT) with amalgam in permanent teeth in high caries-risk Filipino children.

OBJECTIVES: The objective of the study is to evaluate the success rate of amalgam restorations in manually prepared cavities under field conditions within a comprehensive school-based oral health-care program in high caries-risk children. MATERIALS AND METHODS: A total of 1322 restorations were placed in the permanent teeth of 619 high caries risk Filipino children by two dentists and two trained health-care workers. Only hand instruments and an encapsulated amalgam, mixed with a manually powered amalgamator, were used. The restorations were evaluated after a service time of 1 to 5 years using modified atraumatic restorative treatment (ART) criteria. RESULTS: The overall success rate of the amalgam restorations was 95.3% (n = 1260) after a mean service time of 2.7 years (SD = 1.4). Multiple-surface restorations showed significantly higher failure rates (11.4%) than single-surface occlusal (4.7%) and single-surface non-occlusal (2.1%) restorations; 93.6% of large restorations was performed successfully, but had a risk of failure twice to that of small restorations (odds ratio (OR) = 2.141). The score of the decayed, missing, and filled teeth (DMFT) index had significant influence on the success rate. The risk of restoration failure increased by 11.5% for each unit increase in DMFT (OR = 1.148). Neither the operator nor age nor gender of the patient had a significant effect on the success rate of the restorations. CONCLUSION: Amalgam was performed satisfactorily as a filling material when placed under field conditions in manually prepared cavities in the permanent dentition of high caries-risk children. Success of the restorations was influenced by the patient's caries experience (DMFT), restoration size, and service time. CLINICAL RELEVANCE: Manual restorative treatment (MRT) amalgam restorations were performed satisfactorily, but higher dental caries experience and large cavities contribute to lower success rates.

Bond strength of repaired amalgam restorations.

This in vitro study investigated the interfacial flexural strength (FS) of amalgam repairs and the optimal combination of repair materials and mechanical retention required for a consistent and durable repair bond. Amalgam bricks were created, each with 1 end roughened to expose a fresh surface before repair. Four groups followed separate repair protocols: group 1, bonding agent with amalgam; group 2, bonding agent with composite resin; group 3, mechanical retention (slot) with amalgam; and group 4, slot with bonding agent and amalgam. Repaired specimens were stored in artificial saliva for 1, 10, 30, 120, or 360 days before being loaded to failure in a 3-point bending test. Statistical analysis showed significant changes in median FS over time in groups 2 and 4. The effect of the repair method on the FS values after each storage period was significant for most groups except the 30-day storage groups. Amalgam-amalgam repair with adequate condensation yielded the most consistent and durable bond. An amalgam bonding agent could be beneficial when firm condensation on the repair surface cannot be achieved or when tooth structure is involved. Composite resin can be a viable option for amalgam repair in an esthetically demanding region, but proper mechanical modification of the amalgam surface and selection of the proper bonding system are essential.

Replacement versus repair of defective restorations in adults: amalgam.

BACKGROUND: Amalgam is a common filling material for posterior teeth, as with any restoration amalgams have a finite life-span. Traditionally replacement was the ideal approach to treat defective amalgam restorations, however, repair offers an alternative more conservative approach where restorations are only partially defective. Repairing a restoration has the potential of taking less time and may sometimes be performed without the use of local anaesthesia hence it may be less distressing for a patient when compared with replacement. Repair of amalgam restorations is often more conservative of the tooth structure than replacement. OBJECTIVES: To evaluate the effects of replacing (with amalgam) versus repair (with amalgam) in the management of defective amalgam dental restorations in permanent molar and premolar teeth. SEARCH METHODS: For the identification of studies relevant to this review we searched the Cochrane Oral Health Group's Trials Register (to 5 August 2013); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 7); MEDLINE via OVID (1946 to 5 August 2013); EMBASE via OVID (1980 to 5 August 2013); BIOSIS via Web of Knowledge (1969 to 5 August 2013); Web of Science (1945 to 5 August 2013) and OpenGrey (to 5 August 2013). Researchers, experts and organisations known to be involved in this field were contacted in order to trace unpublished or ongoing studies. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Trials were selected if they met the following criteria: randomised controlled trial (including split-mouth studies), involving replacement and repair of amalgam restorations in adults with a defective restoration in a molar or premolar tooth/teeth. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed titles and abstracts for each article identified by the searches in order to decide whether the article was likely to be relevant. Full papers were obtained for relevant articles and both review authors studied these. The Cochrane Collaboration statistical guidelines were to be followed for data synthesis. MAIN RESULTS: The search strategy retrieved 201 potentially eligible studies after de-duplication. After examination of the titles and abstracts, full texts of the relevant studies were retrieved but none of these met the inclusion criteria of the review. AUTHORS' CONCLUSIONS: There are no published randomised controlled trials relevant to this review question. There is therefore a need for methodologically sound randomised controlled trials that are reported according to the Consolidated Standards of Reporting Trials (CONSORT) statement (www.consort-statement.org/). Further research also needs to explore qualitatively the views of patients on repairing versus replacement and investigate themes around pain, distress and anxiety, time and costs.

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

BACKGROUND: Amalgam has been the traditional material for filling cavities in posterior teeth for the last 150 years and, due to its effectiveness and cost, amalgam is still the restorative material of choice in certain parts of the world. In recent times, however, there have been concerns over the use of amalgam restorations (fillings), relating to the mercury release in the body and the environmental impact following its disposal. Resin composites have become an esthetic alternative to amalgam restorations and there has been a remarkable improvement of its mechanical properties to restore posterior teeth.There is need to review new evidence comparing the effectiveness of both restorations. OBJECTIVES: To examine the effects of direct composite resin fillings versus amalgam fillings for permanent posterior teeth, primarily on restoration failure. SEARCH METHODS: We searched the Cochrane Oral Health Group's Trials Register (to 22 October 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 9), MEDLINE via OVID (1946 to 22 October 2013), EMBASE via OVID (1980 to 22 October 2013), and LILACs via BIREME Virtual Health Library (1980 to 22 October 2013). We applied no restrictions on language or date of publication when searching the electronic databases. We contacted manufacturers of dental materials to obtain any unpublished studies. SELECTION CRITERIA: Randomized controlled trials comparing dental resin composites with dental amalgams in permanent posterior teeth. We excluded studies having a follow-up period of less than three years. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by The Cochrane Collaboration. MAIN RESULTS: Of the 2205 retrieved references, we included seven trials (10 articles) in the systematic review. Two trials were parallel group studies involving 1645 composite restorations and 1365 amalgam restorations (921 children) in the analysis. The other five trials were split-mouth studies involving 1620 composite restorations and 570 amalgam restorations in an unclear number of children. Due to major problems with the reporting of the data for the five split-mouth trials, the primary analysis is based on the two parallel group trials. We judged all seven trials to be at high risk of bias and we analyzed 3265 composite restorations and 1935 amalgam restorations.The parallel group trials indicated that resin restorations had a significantly higher risk of failure than amalgam restorations (risk ratio (RR) 1.89, 95% confidence interval (CI) 1.52 to 2.35, P value < 0.001 (fixed-effect model) (low-quality evidence)) and increased risk of secondary caries (RR 2.14, 95% CI 1.67 to 2.74, P value < 0.001 (low-quality evidence)) but no evidence of an increased risk of restoration fracture (RR 0.87, 95% CI 0.46 to 1.64, P value = 0.66 (moderate-quality evidence)). The results from the split-mouth trials were consistent with those of the parallel group trials.Adverse effects of dental restorations were reported in two trials. The outcomes considered were neurobehavioral function, renal function, psychosocial function, and physical development. The investigators found no difference in adverse effects between composite and amalgam restorations. However, the results should be interpreted with caution as none of the outcomes were reported in more than one trial. AUTHORS' CONCLUSIONS: There is low-quality evidence to suggest that resin composites lead to higher failure rates and risk of secondary caries than amalgam restorations. This review reinforces the benefit of amalgam restorations and the results are particularly useful in parts of the world where amalgam is still the material of choice to restore posterior teeth with proximal caries. Though the review found insufficient evidence to support or refute any adverse effects amalgam may have on patients, new research is unlikely to change opinion on its safety and due to the decision for a global phase-down of amalgam (Minamata Convention on Mercury) general opinion on its safety is unlikely to change.

Defective amalgam restorations--repair or replace?

DATA SOURCES: The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, BIOSIS via Web of Knowledge, Web of Science and Opengrey databases were searched. In addition researchers and experts in the field were contacted to trace unpublished or ongoing studies. No restrictions were placed on the language or date of publication. STUDY SELECTION: Randomised controlled trials (including split-mouth studies), involving replacement and repair of amalgam restorations in adults with a defective molar restoration in permanent molar or premolar teeth were to be considered. DATA EXTRACTION AND SYNTHESIS: Two review authors independently assessed titles and abstracts for each article identified by the searches in order to decide whether the article was likely to be relevant. Full papers were obtained for relevant articles and both review authors studied these. The Cochrane Collaboration statistical guidelines were to be followed for data synthesis. RESULTS: The search strategy retrieved 201 potentially eligible studies after de-duplication. After examination of the titles and abstracts, full texts of the relevant studies were retrieved but none of these met the inclusion criteria of the review. CONCLUSIONS: There are no published randomised controlled trials relevant to this review question. There is therefore a need for methodologically sound randomised controlled trials that are reported according to the Consolidated Standards of Reporting Trials (CONSORT) statement (www.consort-statement.org/). Further research also needs to explore qualitatively the views of patients on repairing versus replacement and investigate themes around pain, distress and anxiety, time and costs.

Amalgam or composite fillings--which material lasts longer?

DATA SOURCES: Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase and LILACS. Hand searched relevant journals and attempted contact with authors of unpublished studies and manufacturers. STUDY SELECTION: Randomised controlled trials comparing dental resin composites with dental amalgams in permanent posterior teeth with a minimum follow up of three years were eligible. DATA EXTRACTION AND SYNTHESIS: Data were extracted independently by a minimum of two review authors using specially designed data extraction forms. Risk of bias was assessed using the Cochrane risk of bias tool. Relative risks and 95% CIs were extracted for dichotomous data and mean difference (MD) or standardised mean difference (SMD) for continuous data. Relative risk was combined in a meta-analysis. RESULTS: Seven studies were included. Two were parallel and five split-mouth design. Data from 871 participants were available from the two parallel studies but several of the split-mouth studies did not report the number of participants. All studies were considered at high risk of bias. Only data from the two parallel studies were included in the primary meta-analysis. Failure rates in these studies were recorded for between five and seven years. The risk ratio of failure for composite versus amalgam was 1.89 with 95% CI of 1.52-2.35. The increased failure was primarily due to caries rather than fracture. CONCLUSIONS: There is low-quality evidence to suggest that resin composites lead to higher failure rates and risk of secondary caries than amalgam restorations.