Trends in the placement of posterior composites in dental schools.
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The aim of this paper is to review trends in the teaching of posterior composites in the United States, Canada, Ireland, and the United Kingdom over the last fifteen years. The authors compared the results of surveys of the teaching of posterior composites performed in 1989, 1997, and 2004-05. Historical and contemporary international trends were investigated. The amount of clinical and didactic teaching of posterior composites has increased over the past fifteen years. From a time over fifteen years ago, when very few dental students placed posterior composites in dental school, approximately one-third of posterior plastic restorations placed by U.S., Irish, and UK dental students are now composite, with the corresponding finding for Canadian dental schools being approximately 50 percent. Some variations were noted between dental schools in terms of the teaching of contraindications to placement as well as lining and basing techniques. There was some inappropriate teaching of techniques, in particular, in relation to the use of transparent matrix bands and light transmitting wedges. There was also evidence of limited student exposure to newer forms of technology, notably LED curing light units. There have been clear increases in the teaching of posterior composites in the United States, Canada, the United Kingdom, and Ireland in recent years; however, the proportion of posterior composite restorations placed by dental students relative to dental amalgams does not yet match the typical situation in contemporary clinical practice. Dental schools have a responsibility to ensure that their curricula are evidence-based to best prepare their students to meet the needs and expectations of their future patients. (+info)
Dental amalgam restorations and children's neuropsychological function: the New England Children's Amalgam Trial.
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BACKGROUND: A concern persists that children's exposure to mercury vapor from dental amalgams produces neurotoxicity. OBJECTIVE: Our goal was to compare the neuropsychological function of children, without prior exposure to dental amalgam, whose caries were repaired using either dental amalgam or mercury-free composite materials. METHODS: We conducted a randomized controlled trial involving 534 6- to 10-year-old urban and rural children who were assessed yearly for 5 years using a battery of tests of intelligence, achievement, language, memory, learning, visual-spatial skills, verbal fluency, fine motor function, problem solving, attention, and executive function. RESULTS: Although the mean urinary mercury concentration was greater among children in the amalgam group than the composite group (0.9 vs. 0.6 microg/g creatinine), few significant differences were found between the test scores of children in the two groups. The differences found were inconsistent in direction. Analyses using two cumulative exposure indices--surface years of amalgam and urinary mercury concentration--produced similar results. CONCLUSIONS: Exposure to elemental mercury in amalgam at the levels experienced by the children who participated in the trial did not result in significant effects on neuropsychological function within the 5-year follow-up period. (+info)
Analysis of the diametral compressive bond strength between composite resin and amalgam in different stages of oxidation.
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AIM: Amalcomp is a technique that combines composite resin to amalgam in restorative procedures to improve esthetics and minimize the negative effects of polymerization on dental tissues. The objective of this in vitro study was to measure the diametral compressive bond strength between Fill Magic composite (Vigodent) versus Permite (DFL) or Velvalloy (SS White) amalgams in different oxidation stages. METHODS: Twenty-four cylinders of each amalgam brand were fabricated using a Teflon matrix and divided into 3 groups according to the immersion period in artificial saliva for oxidation: A (1 day), B (7 days) and C (30 days). After immersion, the amalgam cylinders were bonded to the composite specimens using the Scotch Bond Multi Use Plus (3M) bonding system. Diametral compression assays were then carried out in an EMIC-MEM 2000 universal testing machine set to 0.5 mm/min. Statistical analysis was performed using ANOVA and Tukey's test. RESULTS: The mean recorded strength (MPa) for each oxidation group was: A=9.71, B=8.21 and C=6.98 (A>B = C; P<0.01). Permite (7.24) provided significantly less adhesion to the composite than Velvalloy (9.36; P<0.05). There was no interaction between the factors alloy, resin and time. CONCLUSIONS: Under the conditions of this study, the less oxidized amalgam showed the greatest diametral compressive strength values. (+info)
A survey of failed post-retained restorations.
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Survival of endodontically treated, post-restored teeth depends on a multitude of factors, all of which are practically impossible to include in a randomized, controlled clinical study. The purpose of this survey was to characterize and analyze reported failures of post-retained restorations to identify factors critical to failure and to type of failure. A questionnaire was mailed to private practitioners in Denmark with a request to complete the questionnaire whenever a patient presented with a failed post-retained restoration. Information was gathered on factors related to the patient, the tooth, the restorative materials, and the techniques. Two-hundred and sixty questionnaires were collected from 171 practitioners over a 3-year period. Functioning time until failure varied between 3 months and 38 years. Mean survival time until failure was 11 years. Of the failed restorations, 61% had functioned for 10 years or less. Fracture of the tooth was the most common type of failure reported, followed by loosening of the post and fracture of the post. Tapered posts implied an increased risk of tooth fracture compared to loosening or fracture of the post, and the relative risk of tooth fracture increased with the functioning time until failure. Fracture of the post was more common among male than female patients. On the basis of this survey of failed post-retained restorations, it was concluded that tapered posts were associated with a higher risk of tooth fracture than were parallel-sided posts. (+info)
Maternal dental history, child's birth outcome and early cognitive development.
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Prenatal exposure to high levels of mercury, radiation and inflammation have been associated with adverse reproductive outcomes such as increases in preterm delivery, low birthweight and delayed neurodevelopment. Few data are available to evaluate the potential effects of prenatal low-level exposure to these factors as may occur during dental care. We evaluated maternal dental history prior to and during pregnancy in relation to birth outcomes and early communicative development among offspring in a large cohort (n = 7375) of British children born in 1991-92. Dental history was assessed by questionnaire. The child's communicative development was assessed using the MacArthur Communicative Development Inventory at 15 months of age. Total mercury was measured in umbilical cord tissue for a subset of the children. Overall, dental care, including amalgam fillings, was not associated with birth outcomes or language development. Having X-rays taken during pregnancy was not associated with birthweight measured continuously (b = 14.7, P = 0.4), but was associated with slightly increased odds of having a term, low-birthweight baby (OR 1.9, [95% confidence interval 1.0, 3.4]). More detailed evaluation of the potential adverse effects of elective dental treatment during pregnancy, particularly dental X-rays, may be warranted. (+info)
Western Australian dental graduates' perception of preparedness to practice: a five-year follow-up.
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The School of Dentistry in Western Australia developed a pregraduation intern year in which final-year students, having completed their didactic education, undertook a focused clinical experiential program (CEP) over an extended year. This program was implemented for the first time in 2002. The aim of this study was to identify the strengths and weaknesses of the curriculum as perceived by graduates and to compare the perceptions of those graduates who did the CEP to those who did not. A survey with questions based on the graduate outcomes of the dental school was mailed to all graduates from 2000, 2001 (did not complete CEP), and 2004 (completed CEP). The response rate was 66 percent (n=57) and included twenty-nine respondents who graduated before implementation of the CEP and twenty-eight who completed the CEP. Most respondents (80 percent) were in the twenty to twenty-nine age group, and there were slightly more males (53 percent). Learning outcome items with the highest mean scores were practicing universal precautions (4.2), behaving ethically (4.2), and demonstrating a satisfactory level of core dental knowledge (4.2). Practical skills outcomes with the highest scores were amalgam restorations (4.3), anterior endodontics (4.3), and single crowns (3.9). When comparing the respondents who did CEP (51 percent) with those who did not (49 percent), there were few significant differences. The general findings from this survey were that most graduates, whether completing the CEP or not, perceived themselves to be prepared, competent, and confident to practice as dentists and were most confident in managing problems that they most frequently encountered during training. (+info)
Neuropsychological function in children with blood lead levels <10 microg/dL.
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Clear adverse effects of blood lead levels >or=10 microg/dL have been documented in children. Given that the majority of US children have levels below 10 microg/dL, clarification of adverse effects below this cutoff value is needed. Our study evaluated the associations between blood lead levels <10 microg/dL and a broad spectrum of children's cognitive abilities. Data were analyzed from 534 children aged 6-10, enrolled in the New England Children's Amalgam Trial (NECAT) from the urban area of Boston, Massachusetts and rural Farmington, Maine. Adjusting for covariates (age, race, socioeconomic status, and primary caregiver IQ), children with 5-10 microg/dL had 5.0 (S.D. 2.3) points lower IQ scores compared to children with blood lead levels of 1-2 microg/dL (p=0.03). Verbal IQ was more negatively affected than performance IQ, with the most prominent decrement occurring in children's vocabulary. Wechsler Individual Achievement Test scores were strongly negatively associated with blood lead levels of 5-10 microg/dL. In adjusted analyses, children with levels of 5-10 microg/dL scored 7.8 (S.D. 2.4) and 6.9 (S.D. 2.2) points lower on reading and math composite scores, respectively, compared to children with levels of 1-2 microg/dL (p<0.01). Finally, levels of 5-10 microg/dL were associated with decreased attention and working memory. Other than associations of lead exposure with achievement, which even persisted after adjustment for child IQ, the most pronounced deficits were in the areas of spatial attention and executive function. Overall, our analyses support prior research that children's blood levels <10 microg/dL are related to compromised cognition and highlight that these may especially be related to academic achievement. (+info)
Economic impact of regulating the use of amalgam restorations.
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OBJECTIVE: This article estimates the financial impact of a ban on amalgam restorations for selected population groups: the entire population, children, and children and women of childbearing age. METHODS: Using claim and enrollment data from Delta Dental of Michigan, Ohio, and Indiana and the American Dental Association Survey of Dental Services Rendered, we estimated the per capita use and annual rate of change in amalgam restorations for each age, gender, and socioeconomic subgroup. We used population projections to obtain national estimates of amalgam use, and the dental component of the Consumer Price Index to estimate the annual rate of change in fees. We then calculated the number of dental amalgams affected by the regulation, and the fees for each of the years 2005 to 2020. RESULTS: If amalgam restorations are banned for the entire population, the average price of restorations before 2005 and after the ban would increase $52 from $278 to $330, and total expenditures for restorations would increase from $46.2 billion to $49.7 billion. As the price of restorations increases, there would be 15,444,021 fewer restorations inserted per year. The estimated first-year impact of banning dental amalgams in the entire population is an increase in expenditures of $8.2 billion. CONCLUSIONS: An amalgam ban would have a substantial short- and long-term impact on increasing expenditures for dental care, decreasing utilization, and increasing untreated disease. Based on the available evidence, we believe that state legislatures should seriously consider these effects when contemplating possible restrictions on the use of amalgam restorations. (+info)