21 CFR 872.3110 - Dental amalgam capsule.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental amalgam capsule. 872.3110 Section 872.3110...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3110 Dental amalgam capsule. (a) Identification. A dental amalgam capsule is a container device in which silver alloy is intended to be mixed with mercury...

Increased Zn/Glutathione Levels and Higher Superoxide Dismutase-1 Activity as Biomarkers of Oxidative Stress in Women with Long-Term Dental Amalgam Fillings: Correlation between Mercury/Aluminium Levels (in Hair) and Antioxidant Systems in Plasma

PubMed Central

Cabaña-Muñoz, María Eugenia; Parmigiani-Izquierdo, José María; Bravo-González, Luis Alberto; Kyung, Hee-Moon; Merino, José Joaquín

2015-01-01

Background The induction of oxidative stress by Hg can affect antioxidant enzymes. However, epidemiological studies have failed to establish clear association between dental fillings presence and health problems. Objectives To determine whether heavy metals (in hair), antioxidant enzymes (SOD-1) and glutathione levels could be affected by the chronic presence of heavy metals in women who had dental amalgam fillings. Materials and Methods 55 hair samples (42 females with amalgam fillings and 13 female control subjects) were obtained. All subjects (mean age 44 years) who had dental amalgam filling for more than 10 years (average 15 years). Certain metals were quantified by ICP-MS (Mass Spectrophotometry) in hair (μg/g: Al, Hg, Ba, Ag, Sb, As, Be, Bi, Cd, Pb, Pt, Tl, Th, U, Ni, Sn, Ti) and SOD-1 and Glutathione (reduced form) levels in plasma. Data were compared with controls without amalgams, and analyzed to identify any significant relation between metals and the total number of amalgam fillings, comparing those with four or less (n = 27) with those with more than four (n = 15). As no significant differences were detected, the two groups were pooled (Amlgam; n = 42). Findings Hg, Ag, Al and Ba were higher in the amalgam group but without significant differences for most of the heavy metals analyzed. Increased SOD-1 activity and glutathione levels (reduced form) were observed in the amalgam group. Aluminum (Al) correlated with glutathione levels while Hg levels correlated with SOD-1. The observed Al/glutathione and Hg/SOD-1 correlation could be adaptive responses against the chronic presence of mercury. Conclusions Hg, Ag, Al and Ba levels increased in women who had dental amalgam fillings for long periods. Al correlated with glutathione, and Hg with SOD-1. SOD-1 may be a possible biomarker for assessing chronic Hg toxicity. PMID:26076368

Mercury in dental amalgam: Are our health care workers at risk?

PubMed

Sahani, M; Sulaiman, N S; Tan, B S; Yahya, N A; Anual, Z F; Mahiyuddin, W R Wan; Khan, M F; Muttalib, K A

2016-11-01

Dental amalgam in fillings exposes workers to mercury. The exposure to mercury was investigated among 1871 dental health care workers. The aim of the study was to evaluate the risk of mercury exposure among dental compared to nondental health care workers and to determine other risk factors for mercury exposure. Respondents answered questionnaires to obtain demographic, personal, professional, and workplace information and were examined for their own amalgam fillings. Chronic mercury exposure was assessed through urinary mercury levels. In total, 1409 dental and 462 nondental health care workers participated in the study. Median urine mercury levels for dental and nondental health care workers were 2.75 μg/L (interquartile range [IQR] = 3.0175) and 2.66 μg/L (IQR = 3.04) respectively. For mercury exposure, there were no significant risk factor found among the workers involved within the dental care. The Mann-Whitney test showed that urine mercury levels were significantly different between respondents who eat seafood more than 5 times per week compared to those who eat it less frequently or not at all (p = 0.003). The urinary mercury levels indicated significant difference between dental workers in their practice using squeeze cloths (Mann-Whitney test, p = 0.03). Multiple logistic regression showed that only the usage of cosmetic products that might contain mercury was found to be significantly associated with the urinary mercury levels (odds ratio [OR] = 15.237; CI: 3.612-64.276). Therefore, mean urinary mercury levels of health care workers were low. Exposure to dental amalgam is not associated with high mercury exposure. However, usage of cosmetic products containing mercury and high seafood consumption may lead to the increase of exposure to mercury. Exposure to the high levels of mercury from dental amalgam can lead to serious health effects among the dental health care workers. Nationwide chronic mercury exposure among dental personnel was assessed through

75 FR 33169 - Dental Devices: Classification of Dental Amalgam, Reclassification of Dental Mercury, Designation...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-11

.... FDA-2008-N-0163] (formerly Docket No. 2001N-0067) RIN 0910-AG21 Dental Devices: Classification of Dental Amalgam, Reclassification of Dental Mercury, Designation of Special Controls for Dental Amalgam... the Federal Register of August 4, 2009 (74 FR 38686) which classified dental amalgam as a class II...

Increased mercury emissions from modern dental amalgams.

PubMed

Bengtsson, Ulf G; Hylander, Lars D

2017-04-01

All types of dental amalgams contain mercury, which partly is emitted as mercury vapor. All types of dental amalgams corrode after being placed in the oral cavity. Modern high copper amalgams exhibit two new traits of increased instability. Firstly, when subjected to wear/polishing, droplets rich in mercury are formed on the surface, showing that mercury is not being strongly bonded to the base or alloy metals. Secondly, high copper amalgams emit substantially larger amounts of mercury vapor than the low copper amalgams used before the 1970s. High copper amalgams has been developed with focus on mechanical strength and corrosion resistance, but has been sub-optimized in other aspects, resulting in increased instability and higher emission of mercury vapor. This has not been presented to policy makers and scientists. Both low and high copper amalgams undergo a transformation process for several years after placement, resulting in a substantial reduction in mercury content, but there exist no limit for maximum allowed emission of mercury from dental amalgams. These modern high copper amalgams are nowadays totally dominating the European, US and other markets, resulting in significant emissions of mercury, not considered when judging their suitability for dental restoration.

Mercury vapour exposure during dental student training in amalgam removal

PubMed Central

2013-01-01

Background Amalgam that is used for dental fillings contains approximately 50% elemental mercury. During dental student training, amalgam is often removed by drilling without the use of water spray and suction, which are protective measures in preventing mercury aerosol. In this study we measured mercury vapor levels in ambient air during amalgam removal as is typically performed in dental training. Methods Mercury vapor levels in ambient air were measured in a dental school laboratory during removal of amalgam fillings from artificial teeth set into a dental jaw simulator. Mercury vapor was measured under three conditions (25 measurements each): with the simultaneous use of water spray and suction, with the use of suction only, and with the use of neither suction nor water spray. These three conditions are all used during dental student training. Results were compared to Alberta occupational exposure limits for mercury vapor in order to assess potential occupational risk to students. Analysis of variance testing was used to compare data obtained under the three conditions. Results When water spray and suction were used, mercury vapor levels ranged from 4.0 to 19.0 μg/m3 (arithmetic mean = 8.0 μg/m3); when suction only was used, mercury vapor levels ranged from 14.0 to 999.0 (999.0 μg/m3 represents the high limit detection of the Jerome analyzer) (arithmetic mean = 141.0 μg/m3); when neither suction nor water was used, the vapor levels ranged from 34.0 to 796.0 μg/m3 (arithmetic mean = 214.0 μg/m3). Conclusions The Alberta Occupational Health and Safety threshold limit value for mercury vapor over an eight-hour time-weighted period is 25.0 μg/m3. The absolute ceiling for mercury vapor, not to be exceeded at any time, is 125.0 μg/m3. When both water spray and suction were used, mercury vapor levels were consistently below this threshold. When suction without water spray was used, mercury vapor levels exceeded the safety threshold 8% of

Implementation of revolutionary legislation for informed consent for dental patients receiving amalgam restorations.

PubMed

Edlich, Richard F; Cross, Catherine L; Dahlstrom, Jill J; Long, William B; Newkirk, Anthony T

2008-01-01

Mercury is one of the most dangerous environmental toxins. Realizing the environmental dangers of mercury, the Norwegian Minister of the Environment and International Development, Erik Solheim, has therefore prohibited the use of mercury in products in Norway. This ban will include dental filling materials (amalgam) and measuring instruments, as well as other products. This ban is valid from January 1, 2008. Sweden announced a similar ban, and dentists in Denmark will no longer be able to use mercury in fillings after April 1, 2008. It is indeed unfortunate that the United States has not taken a leadership role in enacting Informed Consent Legislations for patients receiving dental amalgam restorations. Informed Consent Legislations have been enacted by Maine, California, Connecticut, and Vermont.

"Triple M" Effect: A Proposed Mechanism to Explain Increased Dental Amalgam Microleakage after Exposure to Radiofrequency Electromagnetic Radiation.

PubMed

Mortazavi, Gh; Mortazavi, S A R; Mehdizadeh, A R

2018-03-01

A large body of evidence now indicates that the amount of mercury released from dental amalgam fillings can be significantly accelerated by exposure to radiofrequency electromagnetic fields (RF-EMFs) such as common mobile phones and magnetic resonance imaging (MRI). Studies performed on the increased microleakage of dental amalgam restorations after exposure to RF-EMFs have further supported these findings. Although the accelerated microleakage induced by RF-EMFs is clinically significant, the entire mechanisms of this phenomenon are not clearly understood. In this paper, we introduce "Triple M" effect, a new evidence-based theory which can explain the accelerated microleakage of dental amalgam fillings after exposure to different sources of electromagnetic radiation. Based on this theory, there are saliva-filled tiny spaces between amalgam and the tooth. Exposure of the oral cavity to RF-EMFs increases the energy of these small amounts of saliva. Due to the small mass of saliva in these tiny spaces, a small amount of energy will be required for heating. Moreover, reflection of the radiofrequency radiation on the inner walls of the tiny spaces causes interference which in turn produces some "hot spots" in these spaces. Finally, formation of gas bubbles in response to increased temperature and very rapid expansion of these bubbles will accelerate the microleakage of amalgam. Experiments that confirm the validity of this theory are discussed.

Micro-PIXE study of metal loss from dental amalgam

NASA Astrophysics Data System (ADS)

Meesat, Ridthee; Sudprasert, Wanwisa; Guibert, Edouard; Wang, Liping; Chappuis, Thibault; Whitlow, Harry J.

2017-08-01

Mercury amalgams have been a topic of controversy ever since their introduction over 150 years ago as a dental material. An interesting question is if metals are released from the amalgam into the enamel and dentine tissue. To elucidate this PIXE mapping was used to investigate metal redistribution in an extracted molar tooth with a ∼30 year old high-Cu content amalgam filling. The tooth was sectioned and polished, and elemental mapping carried out on the amalgam/enamel, bulk amalgam and the wear surface of the amalgam. As expected, the amalgam was multiphase amalgam comprising of Cu-rich and Ag-rich grains with non-uniform distribution of Hg. The amalgam/dentine interface was clearly defined with amalgam elements on one side and C and P from hydroxyapatite on the other side with evidence of only slight interface corrosion. The peaks for Cu Hg and Zn were isolated from interfering signals with concentrations in the enamel tissue, observed to be at, or below the method detection limit. The proximity in energy of the Sn L α and Ca K α , peaks and the background on the Hg M α gave signal overlap which increased the MDL for these elements. Remarkably, a course grain texture in the amalgam was observed just below the biting surface of the amalgam which might be associated with tribochemical processes from mastication. This coupled with the clear absence of the amalgam metals from tooth tissue, even in close proximity to the interface, suggests that for this sample, release of Hg occurred via erosion or dissolution in saliva.

Dental amalgam and mercury vapor release.

PubMed

Osborne, J W

1992-09-01

Dental diseases are among the most common ailments, and dentists in the United States spend over 50% of their time in dental practice rebuilding carious, malformed, and traumatically injured teeth. It is logical, therefore, that the majority of the dental school curriculum is devoted to the diagnosis, prevention, and treatment of teeth with anomalies. Dentists have several choices of materials they can use to accomplish the task of rebuilding teeth. Besides amalgam, they have ceramic materials, resin composites, base-metal and noble casting alloys, and glass-ionomer cements to use to restore the posterior dentition. Each of these restorative materials has advantages and disadvantages, and the clinical judgment as to when a particular material should be used is given a high priority in dental education. Amalgam is the most widely used of these restorative materials, with 92% of dentists listing it as the material of choice in the posterior of the mouth (Clinical Research Associates, 1990). Dentists have been placing amalgams for over 150 years in the US. They placed 150 million last year, which represents over 75 tons of amalgam alloy. The reasons that dentists use this restorative material so frequently are its durability, ease of manipulation, and low cost. Numerous clinical studies have been conducted on the serviceability of amalgam. Most of these have been on the old, low-copper alloys, and results indicate that they last from 8 to 15 years (Bailit et al., 1979; Osborne et al., 1980; Qvist et al., 1986). In the past 20 years, vast improvements have been made in amalgams with the development of the high-copper systems.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomonitoring of DNA damage in peripheral blood lymphocytes of subjects with dental restorative fillings.

PubMed

Di Pietro, Angela; Visalli, Giuseppa; La Maestra, Sebastiano; Micale, Rosanna; Baluce, Barbara; Matarese, Giovanni; Cingano, Luciano; Scoglio, Maria Elena

2008-02-29

Dental fillings provide a major iatrogenic exposure to xenobiotic compounds due to the high prevalence of surface restorations in developed countries. Experimental data suggest that both amalgams, which contain mercury, and resin-based dental materials cause an impairment of the cellular pro- and anti-oxidant redox balance. The aim of this study was to assess the potential genotoxicity of dental restorative compounds in peripheral blood lymphocytes of young exposed subjects compared with controls. The study examined, by use of the comet assay, 68 carefully selected subjects taking into account the major known confounding factors. In the 44 exposed subjects, the mean numbers of restored surfaces was 3.0 and 3.8 in males and females, respectively. Tail length, percentage of DNA in the tail, tail moment or Olive tail moment were twofold higher in the exposed group than in unexposed controls, with significant differences. No significant difference was observed between amalgam and composite fillings. Furthermore, as shown by multivariate analysis, the association between dental fillings and DNA damage was enhanced by the number of fillings and by the exposure time. Among the lifestyle variables, a moderate physical activity showed a protective effect, being inversely correlated to the DNA damage parameters evaluated. On the whole, the use of DNA-migration allowed us to detect for the first time the potential adverse impact on human health of both kinds of dental filling constituents, the amalgams and the methacrylates. The main mechanism underlying the genotoxicity of dental restorative materials of various nature may be ascribed to the ability of both amalgams and methacrylates to trigger the generation of cellular reactive oxygen species, able to cause oxidative DNA lesions.

“Triple M” Effect: A Proposed Mechanism to Explain Increased Dental Amalgam Microleakage after Exposure to Radiofrequency Electromagnetic Radiation

PubMed Central

Mortazavi, Gh.; Mortazavi, S.A.R.; Mehdizadeh, A.R.

2018-01-01

A large body of evidence now indicates that the amount of mercury released from dental amalgam fillings can be significantly accelerated by exposure to radiofrequency electromagnetic fields (RF-EMFs) such as common mobile phones and magnetic resonance imaging (MRI). Studies performed on the increased microleakage of dental amalgam restorations after exposure to RF-EMFs have further supported these findings. Although the accelerated microleakage induced by RF-EMFs is clinically significant, the entire mechanisms of this phenomenon are not clearly understood. In this paper, we introduce “Triple M” effect, a new evidence-based theory which can explain the accelerated microleakage of dental amalgam fillings after exposure to different sources of electromagnetic radiation. Based on this theory, there are saliva-filled tiny spaces between amalgam and the tooth. Exposure of the oral cavity to RF-EMFs increases the energy of these small amounts of saliva. Due to the small mass of saliva in these tiny spaces, a small amount of energy will be required for heating. Moreover, reflection of the radiofrequency radiation on the inner walls of the tiny spaces causes interference which in turn produces some “hot spots” in these spaces. Finally, formation of gas bubbles in response to increased temperature and very rapid expansion of these bubbles will accelerate the microleakage of amalgam. Experiments that confirm the validity of this theory are discussed. PMID:29732349

Increased Release of Mercury from Dental Amalgam Fillings due to Maternal Exposure to Electromagnetic Fields as a Possible Mechanism for the High Rates of Autism in the Offspring: Introducing a Hypothesis.

PubMed

Mortazavi, Gh; Haghani, M; Rastegarian, N; Zarei, S; Mortazavi, S M J

2016-03-01

According to the World Health Organization (WHO), factors such as growing electricity demand, ever-advancing technologies and changes in social behaviour have led to steadily increasing exposure to man-made electromagnetic fields.  Dental amalgam fillings are among the major sources of exposure to elemental mercury vapour in the general population. Although it was previously believed that low levels are mercury (i.g. release of mercury from dental amalgam) is not hazardous, now numerous data indicate that even very low doses of mercury cause toxicity. There are some evidence indicating that perinatal exposure to mercury is significantly associated with an increased risk of developmental disorders such as autism spectrum disorders (ASD) and attention-deficit hyperactivity disorder (ADHD). Furthermore, mercury can decrease the levels of neurotransmitters dopamine, serotonin, noreprenephrine, and acetylcholine in the brain and cause neurological problems. On the other hand, a strong positive correlation between maternal and cord blood mercury levels is found in some studies. We have previously shown that exposure to MRI or microwave radiation emitted by common mobile phones can lead to increased release of mercury from dental amalgam fillings. Moreover, when we investigated the effects of MRI machines with stronger magnetic fields, our previous findings were confirmed. As a strong association between exposure to electromagnetic fields and mercury level has been found in our previous studies, our findings can lead us to this conclusion that maternal exposure to electromagnetic fields in mothers with dental amalgam fillings may cause elevated levels of mercury and trigger the increase in autism rates. Further studies are needed to have a better understanding of the possible role of the increased mercury level after exposure to electromagnetic fields and the rate of autism spectrum disorders in the offspring.

Increased Release of Mercury from Dental Amalgam Fillings due to Maternal Exposure to Electromagnetic Fields as a Possible Mechanism for the High Rates of Autism in the Offspring: Introducing a Hypothesis

PubMed Central

Mortazavi, Gh.; Haghani, M.; Rastegarian, N.; Zarei, S.; Mortazavi, S.M.J.

2016-01-01

According to the World Health Organization (WHO), factors such as growing electricity demand, ever-advancing technologies and changes in social behaviour have led to steadily increasing exposure to man-made electromagnetic fields.  Dental amalgam fillings are among the major sources of exposure to elemental mercury vapour in the general population. Although it was previously believed that low levels are mercury (i.g. release of mercury from dental amalgam) is not hazardous, now numerous data indicate that even very low doses of mercury cause toxicity. There are some evidence indicating that perinatal exposure to mercury is significantly associated with an increased risk of developmental disorders such as autism spectrum disorders (ASD) and attention-deficit hyperactivity disorder (ADHD). Furthermore, mercury can decrease the levels of neurotransmitters dopamine, serotonin, noreprenephrine, and acetylcholine in the brain and cause neurological problems. On the other hand, a strong positive correlation between maternal and cord blood mercury levels is found in some studies. We have previously shown that exposure to MRI or microwave radiation emitted by common mobile phones can lead to increased release of mercury from dental amalgam fillings. Moreover, when we investigated the effects of MRI machines with stronger magnetic fields, our previous findings were confirmed. As a strong association between exposure to electromagnetic fields and mercury level has been found in our previous studies, our findings can lead us to this conclusion that maternal exposure to electromagnetic fields in mothers with dental amalgam fillings may cause elevated levels of mercury and trigger the increase in autism rates. Further studies are needed to have a better understanding of the possible role of the increased mercury level after exposure to electromagnetic fields and the rate of autism spectrum disorders in the offspring. PMID:27026954

Amalgam--fact and fiction.

PubMed

Molin, C

1992-02-01

A brief history of amalgam is given, stressing the role of G. V. Black. The background and the progress of the two Amalgam Wars are sketched. Aspects are presented of the drawbacks of amalgam with respect to toxic effects of, especially, mercury vapor and corrosion products. An account is given of some frequent fallacies concerning the health hazards of dental amalgam fillings and the role of psychosocial factors in the development of illness attributed to amalgam is emphasized.

Nordic dentists' opinions on the safety of amalgam and other dental restorative materials.

PubMed

Widström, E; Haugejorden, O; Sundberg, H; Birn, H

1993-08-01

The safety of amalgam and other restorative materials has caused concern among dental patients in recent years. The aim of this study was to obtain information on dentists' perceived competence in handling different filling materials and their opinions on the safety of these. A random sample of practising dentists in Denmark, Finland, Norway, and Sweden received a mail questionnaire in spring 1990. Answers were received from 1732 dentists (65%). The study showed that the respondents believed that their theoretic knowledge and clinical skills were generally at a high level regarding restorative materials. The risks of the side-effects of gold, ceramic materials, and glass ionomer were considered to be low by about 90% of the respondents. Amalgam was considered to be significantly more hazardous by the Swedish respondents than the others. Interestingly, composite was considered to be associated with a high risk of side-effects by about half of the dentists in all Nordic countries. The dentists' opinions were not found to be greatly influenced by their sex, age, or place of residence but rather by their country and service sector. Against the background of the present lack of scientific evidence on the hazardousness of amalgam or other restorative materials for patients' general health, these findings indicate that dentists are influenced by discussions in the mass media about dental treatment and materials and, of course, by the guidelines given by the health authorities in their own countries. Few dentists were shown to be concerned about occupational risks associated with the use of amalgam, and they had not had their own amalgam fillings replaced.(ABSTRACT TRUNCATED AT 250 WORDS)

A prospective study of prenatal mercury exposure from maternal dental amalgams and autism severity.

PubMed

Geier, David A; Kern, Janet K; Geier, Mark R

2009-01-01

Dental amalgams containing 50% mercury (Hg) have been used in dentistry for the last 150 years, and Hg exposure during key developmental periods was associated with autism spectrum disorders (ASDs). This study examined increased Hg exposure from maternal dental amalgams during pregnancy among 100 qualifying participants born between 1990-1999 and diagnosed with DSM-IV autism (severe) or ASD (mild). Logistic regression analysis (age, gender, race, and region of residency adjusted) by quintile of maternal dental amalgams during pregnancy revealed the ratio of autism:ASD (severe:mild) were about 1 (no effect) for < or =5 amalgams and increased for > or =6 amalgams. Subjects with > or =6 amalgams were 3.2-fold significantly more likely to be diagnosed with autism (severe) in comparison to ASD (mild) than subjects with < or =5 amalgams. Dental amalgam policies should consider Hg exposure in women before and during the child-bearing age and the possibility of subsequent fetal exposure and adverse outcomes.

Is dental amalgam safe for humans? The opinion of the scientific committee of the European Commission

PubMed Central

2011-01-01

It was claimed by the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR)) in a report to the EU-Commission that "....no risks of adverse systemic effects exist and the current use of dental amalgam does not pose a risk of systemic disease..." [1, available from: http://ec.europa.eu/health/ph_risk/committees/04_scenihr/docs/scenihr_o_016.pdf]. SCENIHR disregarded the toxicology of mercury and did not include most important scientific studies in their review. But the real scientific data show that: (a) Dental amalgam is by far the main source of human total mercury body burden. This is proven by autopsy studies which found 2-12 times more mercury in body tissues of individuals with dental amalgam. Autopsy studies are the most valuable and most important studies for examining the amalgam-caused mercury body burden. (b) These autopsy studies have shown consistently that many individuals with amalgam have toxic levels of mercury in their brains or kidneys. (c) There is no correlation between mercury levels in blood or urine, and the levels in body tissues or the severity of clinical symptoms. SCENIHR only relied on levels in urine or blood. (d) The half-life of mercury in the brain can last from several years to decades, thus mercury accumulates over time of amalgam exposure in body tissues to toxic levels. However, SCENIHR state that the half-life of mercury in the body is only "20-90 days". (e) Mercury vapor is about ten times more toxic than lead on human neurons and with synergistic toxicity to other metals. (f) Most studies cited by SCENIHR which conclude that amalgam fillings are safe have severe methodical flaws. PMID:21232090

Dental metal-induced innate reactivity in keratinocytes.

PubMed

Mortazavi, S M J; Mortazavi, Ghazal; Paknahad, Maryam

2016-06-01

In their paper that is published in Toxicology in Vitro, Rachmawati et al. have recently claimed that in spite of the growing concern about the safety of amalgam, negative reports about the health effects of dental amalgam are still scarce or controversial. Substantial evidence indicates that mercury release from dental amalgam fillings may adversely affect human health. Over the past years, we have shown that exposure to electromagnetic fields (EMFs) can increase the release of mercury from dental amalgam fillings. It is worth mentioning that the results of investigations on the microleakage of amalgam fillings following MRI have confirmed our results. Furthermore, exposure to X-rays as a part of the electromagnetic spectrum has also been linked to increased mercury release from dental amalgam fillings. Considering the explosive rise in human exposure to electromagnetic fields, the role of human exposure to EMF as a key factor in increasing the release of mercury from dental amalgam restorations cannot be simply ignored. Copyright © 2016 Elsevier B.V. All rights reserved.

Biomarkers of kidney integrity in children and adolescents with dental amalgam mercury exposure: Findings from the Casa Pia children's amalgam trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woods, James S.; Martin, Michael D.; Leroux, Brian G.

Mercury is toxic to the kidney, and dental amalgam is a source of mercury exposure. Few studies have evaluated the effects of dental amalgam on kidney function in a longitudinal context in children. Here, we evaluated urinary concentrations of glutathione S-transferases (GSTs) {alpha} and {pi} as biomarkers of renal proximal and distal tubular integrity, respectively, and albumin as a biomarker of glomerular integrity in children and adolescents 8-18 years of age over a 7-year course of dental amalgam treatment. Five hundred seven children, 8-12 years of age at baseline, participated in a clinical trial to evaluate the neurobehavioral and renalmore » effects of dental amalgam in children. Subjects were randomized to either dental amalgam or resin composite treatments. Urinary GSTs {alpha} and {pi}, albumin, and creatinine concentrations were measured at baseline and annually in all subjects. Results were evaluated using linear regression analysis. GST-{alpha} concentrations were similar between treatment groups and in each sex and race (white vs. non-white) group in each follow-up year. GST-{pi} levels tended upward over the course of follow-up by four- to six-fold. This increase was seen in all groups irrespective of the treatment, race, or gender. Females had GST-{pi} levels approximately twice those of males at all ages. Albumin concentrations were constant throughout the follow-up period and did not differ by treatment, although females had 39% higher albumin levels than males. Additionally, we found no significant effects of amalgam treatment on the proportion of children with microalbuminuria (>30 mg/g creatinine). These findings are relevant within the context of children's health risk assessment as relates to the safety of mercury exposure from dental amalgam on kidney function. These data also provide normative values for sensitive indices of renal functional integrity that may serve in the evaluation of children and adolescents with renal disorders.« less

A dose-effect analysis of children's exposure to dental amalgam and neuropsychological function: the New England Children's Amalgam Trial.

PubMed

Bellinger, David C; Trachtenberg, Felicia; Daniel, David; Zhang, Annie; Tavares, Mary A; McKinlay, Sonja

2007-09-01

The New England Children's Amalgam Trial (NECAT) was a five-year randomized trial of 534 6- to 10-year-old children that compared the neuropsychological outcomes of those whose caries were restored using dental amalgam with the outcomes of those those whose caries were restored using mercury-free resin-based composite. The primary intention-to-treat analyses did not reveal significant differences between the treatment groups on the primary or secondary outcomes of the administered psychological tests: Full-Scale IQ score on the Wechsler Intelligence Scale for Children-Third Edition, General Memory Index of the Wide Range Assessment of Memory and Learning, and Visual-Motor Composite of the Wide Range Assessment of Visual Motor Abilities. To determine whether treatment group assignment, a dichotomous measure of exposure, was sufficiently sensitive to detect associations between mercury exposure and these outcomes, the authors conducted analyses to evaluate the associations between the primary and secondary outcomes and two continuously distributed indexes of potential exposure, surface-years of amalgam and urinary mercury excretion. Neither index of mercury exposure was significantly associated with any of the three outcomes. The authors found no evidence that exposure to mercury from dental amalgam was associated with any adverse neuropsychological effects over the five-year period after placement of amalgam restorations. Analyses of the outcomes of the NECAT study indicate that use of dental amalgam was not associated with an increase in children's risk of experiencing neuropsychological dysfunction.

Neurotoxicity of dental amalgam is mediated by zinc.

PubMed

Lobner, D; Asrari, M

2003-03-01

The use of dental amalgam is controversial largely because it contains mercury. We tested whether amalgam caused toxicity in neuronal cultures and whether that toxicity was caused by mercury. In this study, we used cortical cell cultures to show for the first time that amalgam causes nerve cell toxicity in culture. However, the toxicity was not blocked by the mercury chelator, 2,3-dimercaptopropane-1-sulphonate (DMPS), but was blocked by the metal chelator, calcium disodium ethylenediaminetetraacetate (CaEDTA). DMPS was an effective mercury chelator in this system, since it blocked mercury toxicity. Of the components that comprise amalgam (mercury, zinc, tin, copper, and silver), only zinc neurotoxicity was blocked by CaEDTA. These results indicate that amalgam is toxic to nerve cells in culture by releasing zinc. While zinc is known to be neurotoxic, ingestion of zinc is not a major concern because zinc levels in the body are tightly regulated.

The Minamata Convention on Mercury: attempting to address the global controversy of dental amalgam use and mercury waste disposal.

PubMed

Mackey, Tim K; Contreras, John T; Liang, Bryan A

2014-02-15

In October 2013, a new international binding treaty instrument called the Minamata Convention on Mercury opened for signature in Minamata City, Japan, the site of arguably the worst public health and environmental disaster involving mercury contamination. The treaty aims to curb the significant health and environmental impacts of mercury pollution and includes provisions addressing the mining, export and import, storage, and waste management of products containing mercury. Importantly, a provision heavily negotiated in the treaty addresses the use of dental fillings using mercury amalgam, an issue that has been subject to decades of global controversy. Though use of dental amalgam is widespread and has benefits, concerns have been raised regarding the potential for human health risk and environmental damage from emissions and improper waste management. While the Minamata Convention attempts to address these issues by calling for a voluntary phase-down of dental amalgam use and commitment to other measures, it falls short by failing to require binding and measurable targets to achieve these goals. In response, the international community should begin exploring ways to strengthen the implementation of the dental amalgam treaty provisions by establishing binding phase-down targets and milestones as well as exploring financing mechanisms to support treaty measures. Through strengthening of the Convention, stakeholders can ensure equitable access to global oral health treatment while also promoting responsible environmental stewardship. Copyright © 2013 Elsevier B.V. All rights reserved.

Mercury from dental amalgam: exposure and risk assessment.

PubMed

Koral, Stephen M

2013-02-01

There has long been an undercurrent within the dental profession of anti-amalgam sentiment, a "mercury-free" movement. To assess whether anything is or is not scientifically wrong with amalgam, one must look to the vast literature on exposure, toxicology, and risk assessment of mercury. The subject of risk assessment goes straight to the heart of the debate over whether a malgam is safe, or not, for unrestricted use in dentistry in the population at large.

Prenatal exposure to dental amalgam: evidence from the Seychelles Child Development Study main cohort.

PubMed

Watson, Gene E; Lynch, Miranda; Myers, Gary J; Shamlaye, Conrad F; Thurston, Sally W; Zareba, Grazyna; Clarkson, Thomas W; Davidson, Philip W

2011-11-01

Dental amalgams contain approximately 50 percent metallic mercury and emit mercury vapor during the life of the restoration. Controversy surrounds whether fetal exposure to mercury vapor resulting from maternal dental amalgam restorations has neurodevelopmental consequences. The authors determined maternal amalgam restoration status during gestation (prenatal exposure to mercury vapor [Hg(0)]) retrospectively in 587 mother-child pairs enrolled in the Seychelles Child Development Study, a prospective longitudinal cohort study of the effects of prenatal and recent postnatal methylmercury (MeHg) exposure on neurodevelopment. They examined covariate-adjusted associations between prenatal maternal amalgam restoration status and the results of six age-appropriate neurodevelopmental tests administered at age 66 months. The authors fit the models without and with adjustment for prenatal and recent postnatal MeHg exposure metrics. The mean number of maternal amalgam restorations present during gestation was 5.1 surfaces (range, 1-22) in the 42.4 percent of mothers who had amalgam restorations. The authors found no significant adverse associations between the number of amalgam surfaces present during gestation and any of the six outcomes, with or without adjustment for prenatal and postnatal MeHg exposure. Results of analyses with the secondary metric, prenatal amalgam occlusal point scores, showed an adverse association in boys only on a letter- and word-identification subtest of a frequently used test of scholastic achievement, whereas girls scored better on several other tests with increasing exposure. This study's results provide no support for the hypothesis that prenatal Hg(0) exposure arising from maternal dental amalgam restorations results in neurobehavioral consequences in the child. These findings require confirmation from a prospective study of coexposure to MeHg and Hg(0).

Corrosion behaviour of high copper dental amalgams.

PubMed

Yap, A U J; Ng, B L; Blackwood, D J

2004-06-01

This study evaluated the corrosion behaviour of two high copper dental amalgam alloys [Dispersalloy (Dentsply-Caulk) and Tytin (Kerr)] in different electrolytes. Amalgam specimens were prepared, coupled to a copper wire, cemented into glass tubes and polished to a 600-grit finish. A corrosion cell was prepared using a carbon counter-electrode, a standard calomel electrode as the reference and amalgam as the working electrode. The alloys were tested in the following mediums at 37 degrees C: (i) artificial saliva based on Fusayama's solution (FS), (ii) artificial saliva with citric acid adjusted to pH 4.0 (FC) and (iii) 1% sodium chloride solution (SC). Corrosion potentials (E(corr)) and corrosion rates (I(corr)) were determined using potentiostatic and impedance spectroscopy methods. Data was subjected to anova/Scheffe's post hoc test at 0.05 significance level. For both alloys, the corrosion potential in FS was significantly greater than in SC. Corrosion potential of Tytin in FS and SC was also significantly greater than in FC. The corrosion rate of Dispersalloy in FC was significantly greater than in FS and SC. For Tytin, corrosion rate in SC was significantly greater than in FS and FC. Although no significant difference in corrosion potential/rate was observed between the alloys when tested in FS, significant differences were observed when electrochemical testing was carried out in FC and SC. The corrosion behaviour of high copper amalgam alloys are both material and environment dependent. Certain food substances may increase the corrosion of high copper amalgams.

In Vitro Description of Macroscopic Changes of Dental Amalgam Discs Subject to High Temperatures to Forensic Purposes.

PubMed

Arcos, Carlos; Díaz, Juan-David; Canencio, Kenny; Rodríguez, Diana; Viveros, Carlos; Vega, Jonathan; Lores, Juliana; Sinisterra, Gustavo; Sepúlveda, Wilmer; Moreno, Freddy

2015-07-01

To describe the behavior of 45 discs of dental amalgam of known dimension prepared from three commercially available brands of dental amalgam (Contour® Kerr®-USA, Admix® SDI®-Australia and Nu Alloy® Newstethic®-Colombia) when subjected to the action of high temperatures (200 °C, 400 °C, 600 °C, 800 °C, 1000 °C). It was hoped to establish parameters that could be used for human dental identification in cases of charred, burned or incinerated human remains. A pseudo-experimental descriptive in-vitro study was designed to describe the macroscopic physical changes to the surface of 45 discs of pre-prepared amalgam of three commercially available brands exposed to a range of high temperatures. Characteristic and repetitive physical changes were a noticeable feature of the discs of amalgam of each brand of amalgam subjected to the different temperature ranges. These physical changes included changes in dimensional stability, changes in texture, changes in colour, changes in the appearance of fissures and cracks and changes in the fracture and fragmentation of the sample. The characteristics of dental amalgam may be of assistance in cases of human identification where charred, burned or incinerated human remains are a feature and where fingerprints or other soft tissue features are unavailable.

High Tensile Strength Amalgams for In-Space Fabrication and Repair

NASA Technical Reports Server (NTRS)

Grugel, Richard N.

2006-01-01

Amalgams are well known for their use in dental practice as a tooth filling material. They have a number of useful attributes that include room temperature fabrication, corrosion resistance, dimensional stability, and very good compressive strength. These properties well serve dental needs but, unfortunately, amalgams have extremely poor tensile strength, a feature that severely limits other potential applications. Improved material properties (strength and temperature) of amalgams may have application to the freeform fabrication of repairs or parts that might be necessary during an extended space mission. Advantages would include, but are not limited to: the ability to produce complex parts, a minimum number of processing steps, minimum crew interaction, high yield - minimum wasted material, reduced gravity compatibility, minimum final finishing, safety, and minimum power consumption. The work presented here shows how the properties of amalgams can be improved by changing particle geometries in conjunction with novel engineering metals.

The Changes in Dentists' Perception and Patient's Acceptance on Amalgam Restoration in Kurdistan-Iraq: A Questionnaire-based Cross-Sectional Study.

PubMed

Faraj, Bestoon Mohammad; Mohammad, Hawzhen Masoud; Mohammad, Kale Masoud

2015-04-01

There has been considerable controversy concerning the health risks and benefits of utilizing mercury-containing amalgam. Across the developing countries, a reduction in the use of dental amalgam in oral health care provision is expected. Assessment of dentists' and patient's attitude of dental amalgam regarding attractiveness, perceived health, and treatment preferences in Kurdistan, Iraq. A 4-page questionnaire comprised two parts, specific for dentist and patient were structured and delivered to each dentist oneself. Both open-ended and close-ended questions about the treatment needs of patients, uses of amalgam and its alternative, the properties and usefulness of different materials. Patient's acceptance was assessed by means of structured questionnaire prepared based on commonly asked questions from routinely daily practice. Questions on the type of filling material in their mouth, previous knowledge of mercury in dental amalgam and disappointment due to mercury hazard and toxicity. They were to indicate their acceptance with filling their cavities by dental amalgam with or without prior information about its mercury content. This part was also accomplished by the dentists participated in this survey. Out of 185 dentists shared, only 39 (21.1%) indicated that amalgam presents no harm for the dentists and patients. While majority of dentists 85 (45.9%) were uncertain about this issue. Amalgam was selected most often 107 (57.8%) as the material of choice for restoring posterior teeth. About 94(50.8%) and 85(45.9%) of the practitioners primarily used glass ionomer/resin-reinforced glass ionomer and composite, respectively. Among 1850 patients received treatment, only 450 (24.32%) claimed to have heard about adverse reactions to dental amalgams. Those who believed it to be safe were 200 (10.82%).Acceptance towards amalgam was 62%. While amalgam was the most common material used for posterior restorations, direct tooth-coloured restorative materials were also

High Tensile Strength Amalgams for In-Space Repair and Fabrication

NASA Technical Reports Server (NTRS)

Grugel, R. N.

2005-01-01

Amalgams are defined as an alloy of mercury with one or more other metals. These, along with those based on gallium (also liquid at near room temperature), are widely used in dental practice as a tooth filling material. Amalgams have a number of useful attributes that indude room temperature compounding. corrosion resistance, dimensional stability, and good compressive strength. These properties well serve dental needs but, unfortunately, amalgams have extremely poor tensile strength, a feature that severely limits their applications. The work presented here demonstrates how, by modifying particle geometry, the tensile strength of amalgams can be increased and thus extending the range of potential applications. This is relevant to, for example, the freeform fabrication of replacement parts that might be necessary during an extended space mission. Advantages, i.e. Figures-of-Merit. include the ability to produce complex parts, minimum crew interaction, high yield - minimum wasted material, reduced gravity compatibility, minimum final finishing, safety, and minimum power consumption.

Dental amalgam and cognitive function in older women: findings from the Nun Study.

PubMed

Saxe, S R; Snowdon, D A; Wekstein, M W; Henry, R G; Grant, F T; Donegan, S J; Wekstein, D R

1995-11-01

The authors determined the number and surface area of occlusal dental amalgams in a group of 129 Roman Catholic sisters who were 75 to 102 years of age. Findings from this study of women with relatively homogeneous adult lifestyles and environments suggest that existing amalgams are not associated with lower performance on eight different tests of cognitive function.

Histological Evaluation to Study the Effects of Dental Amalgam and Composite Restoration on Human Dental Pulp: An in vivo Study

PubMed Central

Chandwani, Neelam D.; Pawar, Mansing G.; Tupkari, Jagdish V.; Yuwanati, Monal

2013-01-01

Objective To study and compare the effects of dental amalgam and composite restorations on human dental pulp. Materials and Methods One hundred sound premolars scheduled for orthodontic extraction were divided equally into two groups: group A, teeth restored with silver amalgam, and group B, teeth restored with composite resin. Each group was equally subdivided into two subgroups [extracted after 24 h (A-1 and B-1) or 7 days (A−2 and B−2)], and the histological changes in the pulp related to the two different materials at the two different intervals were studied. Results It was found that after 24 h, the inflammatory response of the pulp in teeth restored with amalgam and composite was similar (p = 1.00). However, after 7 days, the severity of the inflammatory response of the pulp in teeth restored with amalgam was less compared to that in teeth restored with composite (p = 0.045). Conclusion This study confirmed that amalgam continues to be the mechanically as well as biologically more competent restorative material. Composite could be a promising restorative material to satisfy esthetic needs for a considerable period of time. However, its biological acceptance is still in doubt. PMID:24217468

Curriculum time compared to clinical procedures in amalgam and composite posterior restorations in U.S. dental schools: a preliminary study.

PubMed

Rey, Rosalia; Nimmo, Susan; Childs, Gail S; Behar-Horenstein, Linda S

2015-03-01

Dental clinicians have an expanding range of biomaterial choices for restoring tooth structure. Scientific developments in cariology, advances in dental biomaterials, and patients' esthetic concerns have led to a reduction in amalgam restorations and an increase in composite restorations. The aim of this study was to compare teaching time with students' clinical procedures in amalgam and composite posterior restorations in dental schools across the United States. Academic deans in 60 schools were invited to complete a survey that asked for the amount of instructional time for amalgam and composite posterior restorations and the number of clinical restorations performed by their Classes of 2009, 2010, and 2011. Of these 60, 12 returned surveys with complete data, for a 20% response rate. Responses from these schools showed little change in lecture and preclinical laboratory instruction from 2009 to 2011. There was a slight increase in two-surface restorations for both amalgam and composites; however, the total number of reported composite and amalgam restorations remained the same. Of 204,864 restorations reported, 53% were composite, and 47% were amalgam. There were twice as many multisurface large or complex amalgam restorations as composites. One-surface composite restorations exceeded amalgams. Among the participating schools, there was little to no change between curriculum time and clinical procedures. Findings from this preliminary study reflect a modest increase in two-surface resin-based restorations placed by dental students from 2009 to 2011 and little change in curricular time devoted to teaching amalgam restorations. The total number of posterior composite restorations placed by students in these schools was slightly higher than amalgams.

Comparison of chlorine and chloramine in the release of mercury from dental amalgam.

PubMed

Stone, Mark E; Scott, John W; Schultz, Stephen T; Berry, Denise L; Wilcoxon, Monte; Piwoni, Marv; Panno, Brent; Bordson, Gary

2009-01-01

The purpose of this project was to compare the ability of chlorine (HOCl/OCl(-)) and monochloramine (NH(2)Cl) to mobilize mercury from dental amalgam. Two types of amalgam were used in this investigation: laboratory-prepared amalgam and samples obtained from dental-unit wastewater. For disinfectant exposure simulations, 0.5 g of either the laboratory-generated or clinically obtained amalgam waste was added to 250 mL amber bottles. The amalgam samples were agitated by end-over-end rotation at 30 rpm in the presence of 1 mg/L chlorine, 10 mg/L chlorine, 1 mg/L monochloramine, 10 mg/L monochloramine, or deionized water for intervals of 0 h, 2 h, 4 h, 8 h, and 24 h for the clinically obtained amalgam waste samples and 4 h and 24 h for the laboratory-prepared samples. Chlorine and monochloramine concentrations were measured with a spectrophotometer. Samples were filtered through a 0.45 microm membrane filter and analyzed for mercury with USEPA standard method 245.7. When the two sample types were combined, the mean mercury level in the 1 mg/L chlorine group was 0.020 mg/L (n=25, SD=0.008). The 10 mg/L chlorine group had a mean mercury concentration of 0.59 mg/L (n=25, SD=1.06). The 1 mg/L chloramine group had a mean mercury level of 0.023 mg/L (n=25, SD=0.010). The 10 mg/L chloramine group had a mean mercury level of 0.024 mg/L (n=25, SD=0.011). Independent samples t-tests showed that there was a significant difference between the natural log mercury measurements of 10 mg/L chlorine compared to those of 1 mg/L and 10 mg/L chloramine. Changing from chlorine to chloramine disinfection at water treatment plants would not be expected to produce substantial increases in dissolved mercury levels in dental-unit wastewater.

Neurodevelopmental outcomes at 5 years in children exposed prenatally to maternal dental amalgam: the Seychelles Child Development Nutrition Study.

PubMed

Watson, Gene E; van Wijngaarden, Edwin; Love, Tanzy M T; McSorley, Emeir M; Bonham, Maxine P; Mulhern, Maria S; Yeates, Alison J; Davidson, Philip W; Shamlaye, Conrad F; Strain, J J; Thurston, Sally W; Harrington, Donald; Zareba, Grazyna; Wallace, Julie M W; Myers, Gary J

2013-01-01

Limited human data are available to assess the association between prenatal mercury vapor (Hg⁰)) exposure from maternal dental amalgam restorations and neurodevelopment of children. We evaluated the association between maternal dental amalgam status during gestation and children's neurodevelopmental outcomes at 5 years in the Seychelles Child Development Nutrition Study (SCDNS). Maternal amalgam status was determined prospectively in a longitudinal cohort study examining the associations of prenatal exposure to nutrients and methylmercury (MeHg) with neurodevelopment. A total of 236 mother-child pairs initially enrolled in the SCDNS in 2001 were eligible to participate. Maternal amalgam status was measured as number of amalgam surfaces (the primary metric) and number of occlusal points. The neurodevelopmental assessment battery was comprised of age-appropriate tests of cognitive, language, and perceptual functions, and scholastic achievement. Linear regression analysis controlled for MeHg exposure, maternal fatty acid status, and other covariates relevant to child development. Maternal amalgam status evaluation yielded an average of 7.0 surfaces (range 0-28) and 11.0 occlusal points (range 0-40) during pregnancy. Neither the number of maternal amalgam surfaces nor occlusal points were associated with any outcome. Our findings do not provide evidence to support a relationship between prenatal exposure to Hg⁰ from maternal dental amalgam and neurodevelopmental outcomes in children at 5 years of age. © 2013.

Neurodevelopmental Outcomes at 5 Years in Children Exposed Prenatally to Maternal Dental Amalgam: The Seychelles Child Development Nutrition Study

PubMed Central

Watson, Gene E.; van Wijngaarden, Edwin; Love, Tanzy M.T.; McSorley, Emeir M.; Bonham, Maxine P.; Mulhern, Maria S.; Yeates, Alison J.; Davidson, Philip W.; Shamlaye, Conrad F.; Strain, J.J.; Thurston, Sally W.; Harrington, Donald; Zareba, Grazyna; Wallace, Julie M.W.; Myers, Gary J.

2013-01-01

Limited human data are available to assess the association between prenatal mercury vapor (Hg0) exposure from maternal dental amalgam restorations and neurodevelopment of children. We evaluated the association between maternal dental amalgam status during gestation and children’s neurodevelopmental outcomes at 5 years in the Seychelles Child Development Nutrition Study (SCDNS). Maternal amalgam status was determined prospectively in a longitudinal cohort study examining the associations of prenatal exposure to nutrients and methylmercury (MeHg) with neurodevelopment. A total of 236 mother-child pairs initially enrolled in the SCDNS in 2001 were eligible to participate. Maternal amalgam status was measured as number of amalgam surfaces (the primary metric) and number of occlusal points. The neurodevelopmental assessment battery was comprised of age-appropriate tests of cognitive, language, and perceptual functions, and scholastic achievement. Linear regression analysis controlled for MeHg exposure, maternal fatty acid status, and other covariates relevant to child development. Maternal amalgam status evaluation yielded an average of 7.0 surfaces (range 0–28) and 11.0 occlusal points (range 0–40) during pregnancy. Neither the number of maternal amalgam surfaces nor occlusal points were associated with any outcome. Our findings do not provide evidence to support a relationship between prenatal exposure to Hg0 from maternal dental amalgam and neurodevelopmental outcomes in children at 5 years of age. PMID:23856391

Effect of ball milling on structures and properties of dispersed-type dental amalgam.

PubMed

Chern Lin, Jiin-Huey; Chen, Fred Ying-Yi; Chiang, Hui-Ju; Ju, Chien-Ping

2011-04-01

The purpose of the present study was to investigate the effect of ball milling on the initial mercury vapor release rate and mechanical properties such as compressive strength, diametral tensile strength and creep value, of the dispersed-type dental amalgam, and comparison was made with respect to two commercial amalgam alloys. Ball milling was employed to modify the configuration of the originally spherical-shaped Ag-Cu-Pd dispersant alloy particles. Improvement in mechanical properties while maintaining a low early-stage mercury vapor release rate of the amalgam is attempted. The experimental results show that the amalgam (AmB10) which was made from Ag-Cu-Pd dispersant alloy particles that were ball-milled for 10 min and heat-treated at 300 °C for 2 days exhibited a low initial mercury vapor release rate of 69 pg/mm(2)/s, which was comparable with that of commercial amalgam alloy Tytin (68 pg/mm(2)/s), and was lower than that of Dispersalloy (73 pg/mm(2)/s). As for mechanical properties, amalgam AmB10 exhibited the highest 1h compressive strength (228 MPa), which was higher than that of commercial amalgam alloy Dispersalloy by 72%; while its 24h diametral tensile strength was also the highest (177 MPa), and was higher than that of Dispersalloy by 55%. Furthermore, the creep value of the amalgams made from Ag-Cu-Pd alloy particles with 10 min ball-milling and heat treatment at 300 °C for 2 days was measured to be 0.12%, which was about 20% that of Dispersalloy. It is found that ball milling of the dispersant Ag-Cu-Pd alloy particles for 10 min was able to modify the configuration of the alloy particles into irregular-shapes. Subsequently, heat treatment at 300 °C significantly lowered the initial mercury vapor release rate, increased its 1h compressive strength and 1h diametral tensile strength, and lowered its creep value. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Prenatal Exposure to Dental Amalgam in the Seychelles Child Development Nutrition Study: Associations with Neurodevelopmental Outcomes at 9 and 30 Months

PubMed Central

Watson, Gene E.; Evans, Katie; Thurston, Sally W.; van Wijngaarden, Edwin; Wallace, Julie M. W.; McSorley, Emeir M.; Bonham, Maxine P.; Mulhern, Maria S.; McAfee, Alison J.; Davidson, Philip W.; Shamlaye, Conrad F.; Strain, J.J.; Love, Tanzy; Zareba, Grazyna; Myers, Gary J.

2012-01-01

Background Dental amalgam is approximately 50% metallic mercury and releases mercury vapor into the oral cavity, where it is inhaled and absorbed. Maternal amalgams expose the developing fetus to mercury vapor. Mercury vapor can be toxic, but uncertainty remains whether prenatal amalgam exposure is associated with neurodevelopmental consequences in offspring. Objective To determine if prenatal mercury vapor exposure from maternal dental amalgam is associated with adverse effects to cognition and development in children. Methods We prospectively determined dental amalgam status in a cohort of 300 pregnant women recruited in 2001 in the Republic of Seychelles to study the risks and benefits of fish consumption. The primary exposure measure was maternal amalgam surfaces present during gestation. Maternal occlusal points were a secondary measure. Outcomes were the child’s mental (MDI) and psychomotor (PDI) developmental indices of the Bayley Scales of Infant Development-II (BSID-II) administered at 9 and 30 months. Complete exposure, outcome, and covariate data were available on a subset of 242 mother-child pairs. Results The number of amalgam surfaces was not significantly (p>0.05) associated with either PDI or MDI scores. Similarly, secondary analysis with occlusal points showed no effect on the PDI or MDI scores for boys and girls combined. However, secondary analysis of the 9 month MDI was suggestive of an adverse association present only in girls. Conclusion We found no evidence of an association between our primary exposure metric, amalgam surfaces, and neurodevelopmental endpoints. Secondary analyses using occlusal points supported these findings, but suggested the possibility of an adverse association with the MDI for girls at 9 months. Given the continued widespread use of dental amalgam, we believe additional prospective studies to clarify this issue are a priority. PMID:23064204

Prenatal exposure to dental amalgam in the Seychelles Child Development Nutrition Study: associations with neurodevelopmental outcomes at 9 and 30 months.

PubMed

Watson, Gene E; Evans, Katie; Thurston, Sally W; van Wijngaarden, Edwin; Wallace, Julie M W; McSorley, Emeir M; Bonham, Maxine P; Mulhern, Maria S; McAfee, Alison J; Davidson, Philip W; Shamlaye, Conrad F; Strain, J J; Love, Tanzy; Zareba, Grazyna; Myers, Gary J

2012-12-01

Dental amalgam is approximately 50% metallic mercury and releases mercury vapor into the oral cavity, where it is inhaled and absorbed. Maternal amalgams expose the developing fetus to mercury vapor. Mercury vapor can be toxic, but uncertainty remains whether prenatal amalgam exposure is associated with neurodevelopmental consequences in offspring. To determine if prenatal mercury vapor exposure from maternal dental amalgam is associated with adverse effects to cognition and development in children. We prospectively determined dental amalgam status in a cohort of 300 pregnant women recruited in 2001 in the Republic of Seychelles to study the risks and benefits of fish consumption. The primary exposure measure was maternal amalgam surfaces present during gestation. Maternal occlusal points were a secondary measure. Outcomes were the child's mental (MDI) and psychomotor (PDI) developmental indices of the Bayley Scales of Infant Development-II (BSID-II) administered at 9 and 30 months. Complete exposure, outcome, and covariate data were available on a subset of 242 mother-child pairs. The number of amalgam surfaces was not significantly (p>0.05) associated with either PDI or MDI scores. Similarly, secondary analysis with occlusal points showed no effect on the PDI or MDI scores for boys and girls combined. However, secondary analysis of the 9-month MDI was suggestive of an adverse association present only in girls. We found no evidence of an association between our primary exposure metric, amalgam surfaces, and neurodevelopmental endpoints. Secondary analyses using occlusal points supported these findings, but suggested the possibility of an adverse association with the MDI for girls at 9 months. Given the continued widespread use of dental amalgam, we believe additional prospective studies to clarify this issue are a priority. Copyright © 2012 Elsevier Inc. All rights reserved.

In vitro fabrication of dental filling nanopowder by green route and its antibacterial activity against dental pathogens.

PubMed

Lee, Jeong-Ho; Velmurugan, Palanivel; Park, Jung-Hee; Lee, Kui-Jae; Jin, Jong-Sik; Park, Yool-Jin; Bang, Keuk-Soo; Oh, Byung-Taek

2016-06-01

The aim of this study was to introduce novel Sn, Cu, Hg, and Ag nanopowders (NPs) and a composite nanopowder (NP) synthesized using Salvia miltiorrhiza Bunge (SM) root extract as a reducing and capping agent to improve the antibacterial property of dental filling materials. All of the NPs obtained were characterized using a scanning transmission electron microscope (STEM), and energy dispersive X-ray (EDX) spectrum imaging was performed to map the elemental distributions of the NP composite. Fourier transform infrared (FTIR) spectroscopy was performed to identify the role of various functional groups in all of the obtained NPs and the phyto-compound responsible for the reduction of various metal ions. The X-ray diffraction (XRD) patterns clearly illustrated the crystalline phase of the synthesized NP. The antibacterial properties of the synthesized Sn, Cu, Hg, Ag, composite NP, SM root extract, and commercial amalgam powder were evaluated. The Cu, composite NP, SM root extract and Ag NP displayed excellent antibacterial activity against dental bacteria Streptococcus mutans and Lactobacillus acidophilus. The results of this study require further evaluation for signs of metal toxicity in appropriate animal models. However, the results are encouraging for the application of metal NPs as suitable alternatives for antibiotics and disinfectants, especially in dental filling materials. Copyright © 2016 Elsevier B.V. All rights reserved.

Properties of amalgams made from lathe-cut, high Cu amalgam alloys.

PubMed

Espevik, S

1980-01-01

Two alloys for dental amalgams made from lathe-cut powder with high Cu content have been developed. The alloys have been characterized with respect to physical properties and microstructure. The strongest amalgam exhibited minimal dimensional changes during setting and had low flow and creep values. It had the highest Cu content of the two amalgams investigated and no gamma 2 phase. The epsilon and eta' phases may dispersion-strenthen the amalgam which in compressive strength was comparable to the strongest amalgams available. A new mechanism for gamma 2 disappearance is suggested where Cu replaces Hg directly in the gamma 2 phase thus forming the eta' phase.

Neurological symptoms among dental assistants: a cross-sectional study

PubMed Central

Moen, BE; Hollund, BE; Riise, T

2008-01-01

Background Dental assistants help the dentist in preparing material for filling teeth. Amalgam was the filling material mostly commonly used in Norway before 1980, and declined to about 5% of all fillings in 2005. Amalgam is usually an alloy of silver, copper, tin and mercury. Copper amalgam, giving particularly high exposure to mercury was used in Norway until 1994. Metallic mercury is neurotoxic. Few studies of the health of dental assistants exist, despite their exposure to mercury. There are questions about the existence of possible chronic neurological symptoms today within this working group, due to this exposure. The aim of this study was to compare the occurrence of neurological symptoms among dental assistants likely to be exposed to mercury from work with dental filling material, compared to similar health personnel with no such exposure. Methods All dental assistants still at work and born before 1970 registered in the archives of a trade union in Hordaland county of Norway were invited to participate (response rate 68%, n = 41), as well as a similar number of randomly selected assistant nurses (response rate 87%, n = 64) in the same age group. The participants completed a self-administered, mailed questionnaire, with questions about demographic variables, life-style factors, musculoskeletal, neurological and psychosomatic symptoms (Euroquest). Results The dental assistants reported significant higher occurrence of neurological symptoms; psychosomatic symptoms, problems with memory, concentration, fatigue and sleep disturbance, but not for mood. This was found by analyses of variance, adjusting for age, education, alcohol consumption, smoking and personality traits. For each specific neurological symptom, adjusted logistic regression analyses were performed, showing that these symptoms were mainly from arms, hands, legs and balance organs. Conclusion There is a possibility that the higher occurrence of neurological symptoms among the dental assistants

Neurological symptoms among dental assistants: a cross-sectional study.

PubMed

Moen, Be; Hollund, Be; Riise, T

2008-05-18

Dental assistants help the dentist in preparing material for filling teeth. Amalgam was the filling material mostly commonly used in Norway before 1980, and declined to about 5% of all fillings in 2005. Amalgam is usually an alloy of silver, copper, tin and mercury. Copper amalgam, giving particularly high exposure to mercury was used in Norway until 1994. Metallic mercury is neurotoxic. Few studies of the health of dental assistants exist, despite their exposure to mercury. There are questions about the existence of possible chronic neurological symptoms today within this working group, due to this exposure. The aim of this study was to compare the occurrence of neurological symptoms among dental assistants likely to be exposed to mercury from work with dental filling material, compared to similar health personnel with no such exposure. All dental assistants still at work and born before 1970 registered in the archives of a trade union in Hordaland county of Norway were invited to participate (response rate 68%, n = 41), as well as a similar number of randomly selected assistant nurses (response rate 87%, n = 64) in the same age group. The participants completed a self-administered, mailed questionnaire, with questions about demographic variables, life-style factors, musculoskeletal, neurological and psychosomatic symptoms (Euroquest). The dental assistants reported significant higher occurrence of neurological symptoms; psychosomatic symptoms, problems with memory, concentration, fatigue and sleep disturbance, but not for mood. This was found by analyses of variance, adjusting for age, education, alcohol consumption, smoking and personality traits. For each specific neurological symptom, adjusted logistic regression analyses were performed, showing that these symptoms were mainly from arms, hands, legs and balance organs. There is a possibility that the higher occurrence of neurological symptoms among the dental assistants may be related to their previous work

Glossary of Dental Terms

MedlinePlus

... More print this article enlarge text Glossary of Dental Terms Oral Health Defined Amalgam silver/mercury alloy ... to fill cavities | More Bleaching cosmetic whitening of teeth using peroxide | More Caries cavities, tooth decay | More ...

Making High-Tensile-Strength Amalgam Components

NASA Technical Reports Server (NTRS)

Grugel, Richard

2008-01-01

Structural components made of amalgams can be made to have tensile strengths much greater than previously known to be possible. Amalgams, perhaps best known for their use in dental fillings, have several useful attributes, including room-temperature fabrication, corrosion resistance, dimensional stability, and high compressive strength. However, the range of applications of amalgams has been limited by their very small tensile strengths. Now, it has been discovered that the tensile strength of an amalgam depends critically on the sizes and shapes of the particles from which it is made and, consequently, the tensile strength can be greatly increased through suitable choice of the particles. Heretofore, the powder particles used to make amalgams have been, variously, in the form of micron-sized spheroids or flakes. The tensile reinforcement contributed by the spheroids and flakes is minimal because fracture paths simply go around these particles. However, if spheroids or flakes are replaced by strands having greater lengths, then tensile reinforcement can be increased significantly. The feasibility of this concept was shown in an experiment in which electrical copper wires, serving as demonstration substitutes for copper powder particles, were triturated with gallium by use of a mortar and pestle and the resulting amalgam was compressed into a mold. The tensile strength of the amalgam specimen was then measured and found to be greater than 10(exp 4) psi (greater than about 69 MPa). Much remains to be done to optimize the properties of amalgams for various applications through suitable choice of starting constituents and modification of the trituration and molding processes. The choice of wire size and composition are expected to be especially important. Perusal of phase diagrams of metal mixtures could give insight that would enable choices of solid and liquid metal constituents. Finally, whereas heretofore, only binary alloys have been considered for amalgams

Potential health and environmental issues of mercury-contaminated amalgamators.

PubMed

Roberts, H W; Leonard, D; Osborne, J

2001-01-01

Dental amalgamators may become contaminated internally with metallic mercury. This contamination may result from mercury leakage from capsules during trituration or from the long-term accrual from microscopic exterior contaminants that result from the industrial assembly process. The potential health risk to dental personnel from this contamination is unknown. The authors assessed used amalgamators from the federal service inventory for the amounts of mercury vapor levels, as well as the visual presence of mercury contamination. They evaluated these amalgamators for potential mercury vapor health risk, using established National Institute for Occupational Safety and Health methods and American Conference of Governmental Industrial Hygienists standards. Ten of the 11 amalgamators assessed had measurable mercury vapor levels. Four amalgamators were found to have internal static mercury vapor levels above Occupational Safety and Health Administration ceiling limit thresholds. During a simulated worst-case clinical use protocol, the authors found that no amalgamators produced mercury vapor in the breathing space of dental personnel that exceeded established time-weighted federal mercury vapor limits. Amalgamators may be contaminated internally with metallic mercury. Although the authors detected mercury vapor from these units during aggressive, simulated clinical use, dilution factors combined with room air exchange were found to keep health risks below established federal safety thresholds. Dental personnel should be aware that amalgamators may be contaminated with mercury and produce minute amounts of mercury vapor. These contaminated amalgamators may require disposal as environmentally hazardous waste.

The Post-Amalgam Era: Norwegian Dentists' Experiences with Composite Resins and Repair of Defective Amalgam Restorations.

PubMed

Kopperud, Simen E; Staxrud, Frode; Espelid, Ivar; Tveit, Anne Bjørg

2016-04-22

Amalgam was banned as a dental restorative material in Norway in 2008 due to environmental considerations. An electronic questionnaire was sent to all dentists in the member register of the Norwegian Dental Association (NTF) one year later, to evaluate dentists' satisfaction with alternative restorative materials and to explore dentists' treatment choices of fractured amalgam restorations. Replies were obtained from 61.3%. Composite was the preferred restorative material among 99.1% of the dentists. Secondary caries was the most commonly reported cause of failure (72.7%), followed by restoration fractures (25.1%). Longevity of Class II restorations was estimated to be ≥10 years by 45.8% of the dentists, but 71.2% expected even better longevity if the restoration was made with amalgam. Repair using composite was suggested by 24.9% of the dentists in an amalgam restoration with a fractured cusp. Repair was more often proposed among young dentists (p < 0.01), employees in the Public Dental Service (PDS) (p < 0.01) and dentists working in counties with low dentist density (p = 0.03). There was a tendency towards choosing minimally invasive treatment among dentists who also avoided operative treatment of early approximal lesions (p < 0.01). Norwegian dentists showed positive attitudes towards composite as a restorative material. Most dentists chose minimally- or medium invasive approaches when restoring fractured amalgam restorations.

The Post-Amalgam Era: Norwegian Dentists’ Experiences with Composite Resins and Repair of Defective Amalgam Restorations

PubMed Central

Kopperud, Simen E.; Staxrud, Frode; Espelid, Ivar; Tveit, Anne Bjørg

2016-01-01

Amalgam was banned as a dental restorative material in Norway in 2008 due to environmental considerations. An electronic questionnaire was sent to all dentists in the member register of the Norwegian Dental Association (NTF) one year later, to evaluate dentists’ satisfaction with alternative restorative materials and to explore dentists’ treatment choices of fractured amalgam restorations. Replies were obtained from 61.3%. Composite was the preferred restorative material among 99.1% of the dentists. Secondary caries was the most commonly reported cause of failure (72.7%), followed by restoration fractures (25.1%). Longevity of Class II restorations was estimated to be ≥10 years by 45.8% of the dentists, but 71.2% expected even better longevity if the restoration was made with amalgam. Repair using composite was suggested by 24.9% of the dentists in an amalgam restoration with a fractured cusp. Repair was more often proposed among young dentists (p < 0.01), employees in the Public Dental Service (PDS) (p < 0.01) and dentists working in counties with low dentist density (p = 0.03). There was a tendency towards choosing minimally invasive treatment among dentists who also avoided operative treatment of early approximal lesions (p < 0.01). Norwegian dentists showed positive attitudes towards composite as a restorative material. Most dentists chose minimally- or medium invasive approaches when restoring fractured amalgam restorations. PMID:27110804

Amalgam ablation with the Er:YAG laser

NASA Astrophysics Data System (ADS)

Wigdor, Harvey A.; Visuri, Steven R.; Walsh, Joseph T., Jr.

1995-04-01

Any laser that will be used by dentist to replace the dental drill (handpiece) must remove dental hard tissues safely. These lasers must also have the ability to ablate the restorative dental materials which are present in the teeth being treated. Prior to any laser being used to treat humans a thorough knowledge of the effects of the laser treatment on dental materials must be understood. Cores of dental amalgam were created and sliced into thin wafers for this experiment. Ablation efficiency and thermal changes were evaluated with and without water. It appears as if the Er:YAG laser can effectively ablate amalgam dental material with and without water. The water prevents the temperature from increasing much above baseline and does not reduce efficiency of ablation.

Minor changes in serum levels of cytokines after removal of amalgam restorations.

PubMed

Björkman, Lars; Brokstad, Karl A; Moen, Ketil; Jonsson, Roland

2012-06-01

Dental amalgam restorations release mercury and silver which is absorbed and distributed in the body. Animal studies have shown that both elements may interfere with the host by activation of the immune system in genetically susceptible strains at exposure levels relevant to those from dental amalgam restorations. The aim of this study was to test the hypothesis of no change over time in concentrations of a number of immune mediators in serum after removal of all dental amalgam restorations in patients with health complaints attributed to their amalgam restorations and compare with a healthy reference group. Twenty patients previously examined at a specialty unit for health complaints attributed to dental materials were included in a clinical trial and had all amalgam restorations replaced with other dental restorative materials. Serum samples were collected before amalgam removal and 3 and 12 months after the removal was finished. Twenty blood donors matched for age and gender were used as comparison group. A fluorescent bead-based (Luminex) immunoassay kit was used to measure cytokines, chemokines and growth factors in serum. At baseline, the patient group had slightly higher values for GM-CSF, IL-6, IL-2R, IFN-alpha, IL-7, and IL-12p40/p70 compared with the reference group. After amalgam removal a decrease towards the median value of the reference group was found for GM-CSF, IL-8, and IL-7. In conclusion, removal of all dental amalgam restorations and replacement with other dental restorative materials was associated with decreased concentrations of Th1-type proinflammatory markers in serum. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Distribution of toxic elements in teeth treated with amalgam using μ-energy dispersive X-ray fluorescence

NASA Astrophysics Data System (ADS)

Guerra, M.; Ferreira, C.; Carvalho, M. L.; Santos, J. P.; Pessanha, S.

2016-08-01

Over the years, the presence of mercury in amalgam fillings has raised some safety concerns. Amalgam is one of the most commonly used tooth fillings and contains approximately 50% of elemental mercury and 50% of other metals, mostly silver, tin and copper. Amalgam can release small amounts of mercury vapor over time, and patients can absorb these vapors by inhaling or ingesting them. In this study, 10 human teeth treated with dental amalgam were analyzed using energy dispersive X-ray fluorescence (EDXRF) to study the diffusion of its constituents, Ag, Cu, Sn and Hg. The used EDXRF setup, makes use of a polycapillary lens to focus radiation up to 25 μm allowing the mapping of the elemental distribution in the samples. Quantification was performed using the inbuilt software based on the Fundamental Parameters method for bulk samples, considering a hydroxyapatite matrix. The teeth were longitudinally cut and each slice was scanned from the surface enamel to the inner region (dentin and pulp cavity). Mercury concentration profiles show strong levels of this element close to the amalgam region, decreasing significantly in the dentin, and increasing again up to 40,000 μg·g- 1 in the cavity were the pulp used to exist when the tooth was vital.

Extensive amalgam tattoo on the alveolar-gingival mucosa.

PubMed

Galletta, Vivian C; Artico, Gabriela; Dal Vechio, Aluana M C; Lemos, Celso A; Migliari, Dante A

2011-01-01

Amalgam tattoos are common exogenous pigmented lesions of the oral mucosa occurring mainly by inadvertent placement of amalgam particles into soft tissues. The diagnosis of amalgam tattoo is simple, usually based on clinical findings associated with presence or history of amalgam fillings removal. Intraoral X-rays may be helpful in detecting amalgam-related radiopacity. In cases where amalgam tattoo cannot be differentiated from other causes of oral pigmentation, a biopsy should be performed. This article deals with an extensive amalgam tattoo lesion which required a biopsy for a definitive diagnosis.

Is a drill-less dental filling possible?

PubMed

Quock, Ryan L; Patel, Shalizeh A; Falcao, Felipe A; Barros, Juliana A

2011-09-01

Dental caries, a bacterial process that results in the acidic destruction of tooth structure, has historically been managed by the mechanical excavation of diseased tooth structure and then restoration with a synthetic material. The mechanical excavation of the infected site is most commonly achieved by a dental handpiece, or "drill"; this handpiece may induce stress and anxiety in many patients. Alternatively, a drill-less filling will involve the utilization of silver diamine fluoride (38%) to arrest and prevent dental caries, followed by restoration with a bonded filling material to achieve adequate seal at the lesion margins. This is a minimally invasive procedure that addresses both microbial and mechanical issues posed by dental caries. Copyright © 2011 Elsevier Ltd. All rights reserved.

Marginal adaptation of mineral trioxide aggregate (MTA) compared with amalgam as a root-end filling material: a low-vacuum (LV) versus high-vacuum (HV) SEM study.

PubMed

Shipper, G; Grossman, E S; Botha, A J; Cleaton-Jones, P E

2004-05-01

To compare the marginal adaptation of mineral trioxide aggregate (MTA) or amalgam root-end fillings in extracted teeth under low-vacuum (LV) versus high-vacuum (HV) scanning electron microscope (SEM) viewing conditions. Root-end fillings were placed in 20 extracted single-rooted maxillary teeth. Ten root ends were filled with MTA and the other 10 root ends were filled with amalgam. Two 1 mm thick transverse sections of each root-end filling were cut 0.50 mm (top) and 1.50 mm (bottom) from the apex. Gap size was recorded at eight fixed points along the dentine-filling material interface on each section when uncoated wet (LV wet (LVW)) and dry under LV (0.3 Torr) in a JEOL JSM-5800 SEM and backscatter emission (LV dry uncoated (LVDU)). The sections were then air-dried, gold-coated and gap size was recorded once again at the fixed points under HV (10(-6) Torr; HV dry coated (HVDC)). Specimen cracking, and the size and extent of the crack were noted. Gap sizes at fixed points were smallest under LVW and largest under HVDC SEM conditions. Gaps were smallest in MTA root-end fillings. A General Linear Models Analysis, with gap size as the dependent variable, showed significant effects for extent of crack in dentine, material and viewing condition (P = 0.0001). This study showed that MTA produced a superior marginal adaptation to amalgam, and that LVW conditions showed the lowest gap size. Gap size was influenced by the method of SEM viewing. If only HV SEM viewing conditions are used for MTA and amalgam root-end fillings, a correction factor of 3.5 and 2.2, respectively, may be used to enable relative comparisons of gap size to LVW conditions.

Bio-inspired dental fillings

NASA Astrophysics Data System (ADS)

Deyhle, Hans; Bunk, Oliver; Buser, Stefan; Krastl, Gabriel; Zitzmann, Nicola U.; Ilgenstein, Bernd; Beckmann, Felix; Pfeiffer, Franz; Weiger, Roland; Müller, Bert

2009-08-01

Human teeth are anisotropic composites. Dentin as the core material of the tooth consists of nanometer-sized calcium phosphate crystallites embedded in collagen fiber networks. It shows its anisotropy on the micrometer scale by its well-oriented microtubules. The detailed three-dimensional nanostructure of the hard tissues namely dentin and enamel, however, is not understood, although numerous studies on the anisotropic mechanical properties have been performed and evaluated to explain the tooth function including the enamel-dentin junction acting as effective crack barrier. Small angle X-ray scattering (SAXS) with a spatial resolution in the 10 μm range allows determining the size and orientation of the constituents on the nanometer scale with reasonable precision. So far, only some dental materials, i.e. the fiber reinforced posts exhibit anisotropic properties related to the micrometer-size glass fibers. Dental fillings, composed of nanostructures oriented similar to the natural hard tissues of teeth, however, do not exist at all. The current X-ray-based investigations of extracted human teeth provide evidence for oriented micro- and nanostructures in dentin and enamel. These fundamental quantitative findings result in profound knowledge to develop biologically inspired dental fillings with superior resistance to thermal and mechanical shocks.

Monte Carlo dose calculation in dental amalgam phantom

PubMed Central

Aziz, Mohd. Zahri Abdul; Yusoff, A. L.; Osman, N. D.; Abdullah, R.; Rabaie, N. A.; Salikin, M. S.

2015-01-01

It has become a great challenge in the modern radiation treatment to ensure the accuracy of treatment delivery in electron beam therapy. Tissue inhomogeneity has become one of the factors for accurate dose calculation, and this requires complex algorithm calculation like Monte Carlo (MC). On the other hand, computed tomography (CT) images used in treatment planning system need to be trustful as they are the input in radiotherapy treatment. However, with the presence of metal amalgam in treatment volume, the CT images input showed prominent streak artefact, thus, contributed sources of error. Hence, metal amalgam phantom often creates streak artifacts, which cause an error in the dose calculation. Thus, a streak artifact reduction technique was applied to correct the images, and as a result, better images were observed in terms of structure delineation and density assigning. Furthermore, the amalgam density data were corrected to provide amalgam voxel with accurate density value. As for the errors of dose uncertainties due to metal amalgam, they were reduced from 46% to as low as 2% at d80 (depth of the 80% dose beyond Zmax) using the presented strategies. Considering the number of vital and radiosensitive organs in the head and the neck regions, this correction strategy is suggested in reducing calculation uncertainties through MC calculation. PMID:26500401

Backscattering from dental restorations and splint materials during therapeutic radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farman, A.G.; Sharma, S.; George, D.I.

1985-08-01

Models were constructed to simulate as closely as possible the human oral cavity. Radiation absorbed doses were determined for controls and various test situations involving the presence of dental restorative and splint materials during cobalt-60 irradiation of the models. Adjacent gold full crowns and adjacent solid dental silver amalgam cores both increased the dose to the interproximal gingivae by 20%. Use of orthodontic full bands for splinting the jaws increased the dose to the buccal tissues by an average of 10%. Augmentation of dose through backscatter radiation was determined to be only slight for intracoronal amalgam fillings and stainless steelmore » or plastic bracket splints.« less

Amalgam to tooth-coloured materials--implications for clinical practice and dental education: governmental restrictions and amalgam-usage survey results.

PubMed

Burke, F J Trevor

2004-07-01

To review governmental guidelines on amalgam use worldwide and to assess trends in the usage of amalgam and composite materials in restoration of posterior teeth. A letter was sent to 24 government health agencies or representative organisations requesting details of regulations pertaining to amalgam use. A literature search was carried out in order to identify papers in which the incidence of amalgam and composite restorations was stated. Ten replies were received, indicating few restrictions on the use of amalgam. Results obtained from published work appear to indicate that amalgam use is declining, but at rates which are unclear in many countries because of the paucity of published data. Amalgam use has been found to be decreasing in the USA, Australia and Scandinavia, with lesser decreases being apparent in the UK. There are few restrictions to the use of amalgam worldwide. In countries where data are available, such as USA, Australia and Scandinavia, amalgam use has been found to be decreasing, with smaller decreases being apparent in the UK.

An interview study of persons who attribute health problems to dental filling materials--part two in a triangulation study on 65 and 75 years old Swedes.

PubMed

Ståhlnacke, Katri; Söderfeldt, Björn

2013-01-01

Dental materials are perceived as a health problem by some people, although scientists do not agree about possible causes of such problems. The aim of this paper was to gain a deeper knowledge and understanding of experiences from living with health problems attributed to dental materials. Addressed topics were the type of problem, both as to general and oral health, perceived causes of the problems,their experienced effect on life, and reception by health professionals. Persons, who in a previous large questionnaire study had answered that they had experienced troubles from dental materials and also agreed to answer follow-up questions, were contacted with a request to take part in an interview study. Eleven individual interviews were held.The interviews were transcribed verbatim and the material was analysed according to the Qualitative Content Analysis method. Meaning units were extracted and condensed into a number of codes, which were combined into subcategories, categories, and themes. Four themes were identified: 1) Long-term oral, mental, and somatic difficulties of varying character, caused by dental amalgam. 2) Problems treated mainly by replacement of dental material in fillings. 3) Powerful effects on life, mostly negative. 4) The reception by health professionals was generally good, but with elements of encounters where they felt treated with nonchalance and lack of respect. In conclusion, people who attributed their health difficulties to dental materials had a complex range of problems and the perception was that amalgam/mercury was the cause of the troubles. The reception from health professionals was perceived as generally good, although with occasional negative experiences.

Effect of dental restorative materials on total antioxidant capacity and calcium concentration of unstimulated saliva.

PubMed

Ramezani, Gholam H; Moghadam, Mona-Momeni; Saghiri, Mohammad-Ali; Garcia-Godoy, Franklin; Asatourian, Armen; Aminsobhani, Mohsen; Scarbecz, Mark; Sheibani, Nader

2017-01-01

To evaluate the effect of dental amalgam and composite restorations on total antioxidant capacity (TAC) and calcium (Ca) ion concentration of unstimulated saliva. Forty-eight children aged 6-10 years selected and divided into three groups of sixteen (8 males, 8 females). In group A and B, samples consisted of two class II dental composite or amalgam restorations, while in group C samples were caries-free (control group). Unstimulated saliva from all samples was collected and TAC was measured by spectrophotometry using an adaptation of 2, 2'-azino-di-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) assay. The Ca ion level was estimated by an auto- analyzer. Data were analyzed with one- and two-way ANOVA test, at a p <.05 level of significance. Composite samples showed significantly higher TAC and lower Ca ion levels compared to amalgam and caries-free samples ( p <.05). The TAC values showed only significant difference between groups ( p <.05), while the Ca ion results showed significant differences within and between groups ( p <.05). Dental composite restorations increased TAC and decreased Ca ion levels more than amalgam restorations in saliva. Gender is an effective factor in changes induced in oral cavity as females showed more emphatic reaction to dental filling materials than males. Patients who have dental restorations, especially dental composites, should pay more attention to their dental hygiene, because dental restorations can increase oxidative stress and decrease Ca ion level in saliva, which might jeopardize remineralization process of tooth structures after demineralization. Key words: Amalgam, caries, composite, saliva, total antioxidant capacity.

Performance of a gaseous detector based energy dispersive X-ray fluorescence imaging system: Analysis of human teeth treated with dental amalgam

NASA Astrophysics Data System (ADS)

Silva, A. L. M.; Figueroa, R.; Jaramillo, A.; Carvalho, M. L.; Veloso, J. F. C. A.

2013-08-01

Energy dispersive X-ray fluorescence (EDXRF) imaging systems are of great interest in many applications of different areas, once they allow us to get images of the spatial elemental distribution in the samples. The detector system used in this study is based on a micro patterned gas detector, named Micro-Hole and Strip Plate. The full field of view system, with an active area of 28 × 28 mm2 presents some important features for EDXRF imaging applications, such as a position resolution below 125 μm, an intrinsic energy resolution of about 14% full width at half maximum for 5.9 keV X-rays, and a counting rate capability of 0.5 MHz. In this work, analysis of human teeth treated by dental amalgam was performed by using the EDXRF imaging system mentioned above. The goal of the analysis is to evaluate the system capabilities in the biomedical field by measuring the drift of the major constituents of a dental amalgam, Zn and Hg, throughout the tooth structures. The elemental distribution pattern of these elements obtained during the analysis suggests diffusion of these elements from the amalgam to teeth tissues.

A comparison of glass cermet cement and amalgam restorations in primary molars.

PubMed

Hickel, R; Voss, A

1990-01-01

The aim of this clinical study was to compare the efficacy of GCC with amalgam as a filling material in primary molars. Two hundred fifteen restorations were placed in the first and second primary molars of seventy-four patients, ranging in age from four to ten years. The overall failure rate of amalgam is lower than that of GCC, but not significantly different. In older children, amalgam has greater advantages. An advantage of GCC is the short time required to fill the cavity. This might be an important factor in young and/or difficult children. In these cases amalgam cannot be placed under optimal conditions and, therefore, the results are less satisfactory. GCC is a viable alternative filling material.

Re-treatment decisions for failed posterior fillings by Finnish general practitioners.

PubMed

Heinikainen, Mia; Vehkalahti, Miira; Murtomaa, Heikki

2002-06-01

To evaluate treatment decisions of general dental practitioners (GDPs) in the private and public sector in cases of re-treatment of failed posterior fillings. A questionnaire on six cases from 400 GDPs, selected by stratified randomisation by gender, and main occupation (public vs. private sector). Others were all full-time dental teachers (DTs; n=47) representing clinical disciplines other than surgery and orthodontics. Restorative cases were described in detail, including figures drawn on four subcases involving the first permanent upper molar where the filling to be replaced increased in size from occlusal filling to the entire clinical crown. For each case, respondents chose the optimal treatment from eight alternatives, later re-classified as amalgam restoration, direct composite restoration, prosthetic restoration (indirect composite, cast gold inlay/onlay, ceramic inlay/onlay, ceramic crown, or bridge construction following tooth extraction). For re-treatment of the occlusal filling, composite restoration was preferred both by GDPs (92%) and DTs (83%). For three-surface fillings, prosthetic restorations were dominant in the private sector (OR=2.3; 95% CI: 1.4, 3.8; P<0.001). In total loss of the clinical crown, prosthetic restoration was chosen by all the DTs, public-sector dentists, and 95% of private-sector dentists. No more than 10% of GDPs chose amalgam and 2% gold; the rest chose composites. Treatment decisions were similar in public and private sectors for cases with the smallest and largest fillings. Wide variation in cases of medium-sized restorations indicated a lack of generally accepted guidelines of good clinical practice and of evidence-based treatment practice.

Corrosion behavior and microhardness of three amalgams.

PubMed

Patsurakos, A; Moberg, L E

1988-08-01

The marginal microhardness of three different types of amalgam was tested after 2 months' immersion in an aqueous solution of NaCl (85 mM) and phosphates (Na2HPO4 100 mM and NaH2PO4 100 mM). Amalgams immersed in distilled water were used as controls. The microhardness tests were conducted at a distance of 50 micron from the margins and at the bulk of each specimen. The solutions were analyzed for Sn, Cu, Zn, Ag, and Hg by means of atomic absorption spectrophotometry (AAS). A statistically significant reduction in the marginal microhardness after immersion in the test solution was found for the conventional and the high-Cu single composition amalgam but not for the high-Cu blended amalgam. SEM-examination of cross-sections of the amalgams revealed small areas of subsurface grain boundary corrosion, no deeper than 10 micron for all the amalgams. The SEM-examination of the specimens and AAS analysis of the solutions indicated that the reduction in marginal microhardness was attributed mainly to corrosion of the Cu-rich phases for the high-Cu single composition amalgam and to corrosion of the gamma 2 phase for the conventional amalgam. The phosphates reduced the corrosion of the amalgams in the presence of NaCl. It is concluded that the marginal strength of dental amalgams in a corrosive environment is largely dependent upon their corrosion resistance.

Compositions of surface layers formed on amalgams in air, water, and saline.

PubMed

Hanawa, T; Gnade, B E; Ferracane, J L; Okabe, T; Watari, F

1993-12-01

The surface layers formed on both a zinc-free and a zinc-containing dental amalgam after polishing and aging in air, water, or saline, were characterized using x-ray photoelectron spectroscopy (XPS) to determine the compositions of the surface layers which might govern the release of mercury from amalgam. The XPS data revealed that the formation of the surface layer on the zinc-containing amalgam was affected by the environment in which the amalgam was polished and aged, whereas that on the zinc-free amalgam was not affected. In addition, among the elements contained in amalgam, zinc was the most reactive with the environment, and was preferentially dissolved from amalgam into water or saline. Mercury atoms existed in the metallic state in the surface layer.

A comparison of MTA, Super-EBA, composite and amalgam as root-end filling materials using a bacterial microleakage model.

PubMed

Adamo, H L; Buruiana, R; Schertzer, L; Boylan, R J

1999-05-01

The aim of this study was to compare traditional and newly developed root-end filling materials for resistance to bacterial microleakage. Sixty extracted single-rooted teeth were randomly divided into five groups for root-end filling with mineral trioxide aggregate, Super-EBA, TPH composite resin with ProBond dentine bonding agent, Dispersalloy amalgam with and without ProBond, and positive and negative control groups. Root canals were instrumented using the step-back technique and simulated root-end resections performed. Root-end filling materials were placed in 3 mm ultrasonic retropreparations. Nail varnish was applied to all external root surfaces to the level of the resected root ends to prevent lateral microleakage. Samples were sterilized in an ethylene oxide sterilizer for 12 h. Using a newly designed model system, the apical 3-4 mm of the roots were immersed in BHI culture medium with phenol red indicator within culture chambers. The coronal access of each specimen was inoculated every 48 h with a suspension of Streptococcus salivarius. Culture media were observed every 24 h for colour change indicating bacterial contamination. Media demonstrating colour change were plated for S. salivarius. Samples were observed for 12 weeks. At 4 weeks 10% of specimens from each experimental group had evidence of leakage. At 8 weeks 20% of specimens filled with amalgam without dentine bonding agent, Super-EBA and MTA had evidence of leakage. At 12 weeks minor differences between materials were noted. Under the conditions of the study, despite some variations, there were no statistically significant differences in rate of microleakage among the five groups tested at either 4, 8 or 12 weeks.

Corrosion sealing of amalgam restorations in vitro.

PubMed

Mahler, David B; Pham, Bao V; Adey, Jerry D

2009-01-01

Amalgam restorations, when first placed, have been shown to exhibit a gap at the amalgam/tooth interface. With time in service, this gap fills with corrosion products that have the potential to "seal" the restoration. With the advent of high-copper, more corrosion-resistant amalgams, there has been concern that the time required to create this seal would be increased significantly when compared with low-copper traditional amalgams. The current study was designed to address this concern. Amalgam was condensed into a MACOR mold, simulating a Class I cavity form and then immersed into a 1.0% NaCl solution to simulate oral conditions. Using an air pressure test, the sealing was monitored over time. The results showed that the sealing was influenced by the size of the initial gap prior to immersion as well as corrosion resistance of the amalgam and that a corrosion-resistant amalgam with a small initial gap size can seal as quickly as a corrosion-prone amalgam. Therefore, it is not possible to predict sealing behavior based on corrosion resistance, alone. Furthermore, the presence of zinc in the amalgam alloy has been shown to result in the formation of zinc corrosion products in the amalgam/mold margin, which contributes to more rapid sealing. Analysis of a tooth extracted after 16 years of clinical service that had been restored with an amalgam-containing zinc was also shown to contain zinc corrosion products in the occlusal marginal area. This could explain the reported reduction in marginal fracture of clinically placed amalgam restorations made from zinc-containing alloys.

Class II glass ionomer cermet tunnel, resin sandwich and amalgam restorations over 2 years.

PubMed

Wilkie, R; Lidums, A; Smales, R

1993-08-01

This study compared the clinical behavior of a glass ionomer (polyalkenoate) silver cermet, a posterior resin composite used with the "tunnel" technique, a posterior resin composite used with the "closed sandwich" technique, and a high-copper amalgam for restoring small, proximal surface carious lesions. Two dentists placed 86 restorations in the posterior permanent teeth of 26 adults treated at a dental hospital. Restorations were assessed at 6-month intervals over 2 years for gingivitis adjacent to them, the tightness of proximal contacts, occlusal wear, surface voids, roughness and cracking, surface and marginal staining, and marginal fracture. Small filling defects, surface voids and occlusal wear were obvious with the cermet material, with surface crazing and cracking present in 48% of the tunnel restorations. Two of the posterior resin composites, but none of the amalgam restorations, also failed. The cermet cannot be recommended as a long-term permanent restorative material in situations where it is likely to be subjected to heavy occlusal stresses and abrasive wear.

Mercury Amalgam Diffusion in Human Teeth Probed Using Femtosecond LIBS.

PubMed

Bello, Liciane Toledo; da Ana, Patricia Aparecida; Santos, Dário; Krug, Francisco José; Zezell, Denise Maria; Vieira, Nilson Dias; Samad, Ricardo Elgul

2017-04-01

In this work the diffusion of mercury and other elements from amalgam tooth restorations through the surrounding dental tissue (dentin) was evaluated using femtosecond laser-induced breakdown spectroscopy (fs-LIBS). To achieve this, seven deciduous and eight permanent extracted human molar teeth with occlusal amalgam restorations were half-sectioned and analyzed using pulses from a femtosecond laser. The measurements were performed from the amalgam restoration along the amalgam/dentin interface to the apical direction. It was possible to observe the presence of metallic elements (silver, mercury, copper and tin) emission lines, as well as dental constituent ones, providing fingerprints of each material and comparable data for checking the consistence of the results. It was also shown that the elements penetration depth values in each tooth are usually similar and consistent, for both deciduous and permanent teeth, indicating that all the metals diffuse into the dentin by the same mechanism. We propose that this diffusion mechanism is mainly through liquid dragging inside the dentin tubules. The mercury diffused further in permanent teeth than in deciduous teeth, probably due to the longer diffusion times due to the age of the restorations. It was possible to conclude that the proposed femtosecond-LIBS system can detect the presence of metals in the dental tissue, among the tooth constituent elements, and map the distribution of endogenous and exogenous chemical elements, with a spatial resolution that can be brought under 100 µm.

Inaccurate Dental Charting in an Audit of 1128 General Dental Practice Records.

PubMed

Brown, Nathan L; Jephcote, Victoria E L

2017-03-01

Fourteen dentists at different practices in the UK assessed the dental charts of 1128 patients who were new to the dentist but not new to the practice; 44% of the dental charts were found to be inaccurate. Inaccuracy of the individual practice-based charts ranged between 16% for the best performing practices to 83% for the worst: 5% of dental charts had too many teeth charted and 5% had too few teeth charted; 13% of charts had missed amalgam restorations and 18% had missed tooth-coloured restorations; 5% of charts had amalgam restorations recorded but with the surfaces incorrect (eg an MO restoration charted but a DO restoration actually present); 9% of charts had tooth-coloured restoration surfaces incorrectly recorded. For 7.5% of charts, amalgams were charted but not actually present. Other inaccuracies were also noted. The authors reinforce the requirements of the GDC, the advice of defence organizations, and the forensic importance of accurate dental charts. Clinical relevance: Dental charting forms part of the patient’s dental records, and the GDC requires dentists to maintain complete and accurate dental records.

Prevalence and distribution of dental restorative materials in US Air Force veterans.

PubMed

Albertini, T F; Kingman, A; Brown, L J

1997-01-01

Millions of restorative procedures are performed annually in the United States, yet very little is known about their distribution in the general population. With increasing concern about potential adverse health effects of some restorative materials, a better understanding of the extent of exposure to these materials in the population is important. The purpose of this study is to report the prevalence, patterns, and distribution of dental restorative materials in a population of male veterans. This collaborative study with the US Air Force examined 1,166 male veterans to assess exposure to dental amalgam and other restorative materials. An inventory of dental materials in the study population was obtained through oral examinations. Dental materials were classified into five categories: (1) amalgam; (2) resin; (3) porcelain, cement, or temporary, including ionomer (PCT); (4) cast gold alloys/direct filling gold; and (5) other metals (OM). The mean age of the study participants was 52.9 years. Over 94 percent of the study participants were dentate. The study participants averaged 45.8 restored/replaced surfaces. Restored/replaced surfaces increased with age while the number of teeth decreased with age. The most frequently used restorative material was amalgam, averaging 19.89 surfaces per subject, followed by PCT (9.38), resins (8.99), OM (5.52), and gold (4.91). The distributions of restorative materials varied by age, arch type, and location in the mouth. The study population experienced substantial exposure to dental materials.

Fracture toughness, diametrical strength, and fractography of amalgam and of amalgam to amalgam bonds.

PubMed

Bapna, M S; Mueller, H J

1993-01-01

Chevron-notch fracture toughness, diametrical tensile strength and fractography were evaluated for bulk amalgams and for bonds formed between new and 1-day-old amalgams of the same type. Three types of bonded specimens were prepared: 1) by mechanically roughening the 1-day-old amalgam with 600-grit paper; 2) using a new mercury-rich amalgam; and 3) using a bonding resin, either 4-META or a phosphate ester monomer. Similar values in bond properties were obtained with all bonding techniques for two commercial dispersed-phase bonded amalgams, one of which contained palladium; however, bulk fracture toughness of the palladium-containing amalgam was significantly less than for the palladium-free amalgam. This result reveals that the bonding of amalgam to amalgam, at least for these two amalgams, is a surface-related phenomenon, and thus, the traditional reporting of bonding properties as a percentage of bulk properties loses meaning. Short-rod geometry was more representative of the interfacial bond properties since these samples fractured within the interfacial bonds, while diametrical strength samples often fractured slightly away from the interface. The use of bonding resins did not improve bond fracture toughness for either amalgam, while the diametrical strength improved for one of the amalgams. The use of mercury-rich amalgam significantly improved the fracture toughness over all other techniques for one amalgam while proving to be similar to a 600-grit preparation for the second amalgam.(ABSTRACT TRUNCATED AT 250 WORDS)

Alternatives to silver amalgam and resin composite in pediatric dentistry.

PubMed

Croll, T P

1998-11-01

Silver amalgam has become a less attractive dental restorative material for restoration of primary teeth. After many decades of scientific and nonscientific controversy, use of silver amalgam for primary teeth is waning, not because of its mercury content but because dentistry has come up with more suitable materials. This article reviews the development and use of glass-ionomer silver-cermet cements, resin-modified glass-ionomer cements, and polyacid-modified resin composites (compomers) for restoration of primary teeth.

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

PubMed

Yengopal, Veerasamy; Harnekar, Soraya Yasin; Patel, Naren; Siegfried, Nandi

2016-10-17

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. 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. 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

Dental Effluent Guidelines

EPA Pesticide Factsheets

Overview and documents for Dental Office Category regulation (40 CFR Part 441); comprising pretreatment standards for discharges of dental amalgam pollutants, including mercury, into publicly owned treatment works (POTWs).

[Clinical observation of using composite resin to fill dental attrition on occlusal surface].

PubMed

Guo, Li-juan; Xu, Yan; Chen, Guang-quan

2005-10-01

The purpose of this study was to evaluate the clinical effect of using composite resin to fill dental attrition on occlusal surface. Whether the dental attrition had enough space to the material was determined first. Sometimes grinding the sharp and steep cusps or ridges of the opposite teeth was needed. Then the dental attrition was cleaned thoroughly, and finally filled with CLEARFIL bond and composite resin without preparing cavity. The follow-up period was 1 year. Out of 70 teeth from 25 patients, 52 were successful, 16 were curative, and 2 were failed. The curative rate was 97.14%. The method avoids endangering the dental pulp. It was easily accepted by the patients and operated by dentists, and can be widely applied in clinical cases.

Elution of monomer from different bulk fill dental composite resins.

PubMed

Cebe, Mehmet Ata; Cebe, Fatma; Cengiz, Mehmet Fatih; Cetin, Ali Rıza; Arpag, Osman Fatih; Ozturk, Bora

2015-07-01

The purpose of this study was to evaluate the elution of Bis-GMA, TEGDMA, HEMA, and Bis-EMA monomers from six bulk fill composite resins over four different time periods, using HPLC. Six different composite resin materials were used in the present study: Tetric Evo Ceram Bulk Fill (Ivoclar Vivadent, Amherst, NY), X-tra Fill (VOCO, Cuxhaven, Germany), Sonic Fill (Kerr, Orange, CA, USA), Filtek Bulk Fill (3M ESPE Dental Product, St. Paul, MN), SDR (Dentsply, Konstanz, Germany), EQUIA (GC America INC, Alsip, IL). The samples (4mm thickness, 5mm diameter) were prepared and polymerized for 20s with a light emitted diode unit. After fabrication, each sample was immediately immersed in 75wt% ethanol/water solution used as extraction fluid and stored in the amber colored bottles at room temperature. Ethanol/water samples were taken (0.5mL) at predefined time intervals:10m (T1), 1h (T2), 24h (T3) and 30 days (T4). These samples were analyzed by HPLC. The obtained data were analyzed with one-way ANOVA and Tukey HSD at significance level of p<0.05. Amount of eluted Bis-EMA and Bis-GMA from Tetric Evo Ceram Bulk Fill and amount of eluted TEGDMA and HEMA from X-tra Fill higher than others composites (p<0.05). Residual monomers were eluted from bulk fill composite resins in all time periods and the amount of eluted monomers was increased with time. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Sensibility of Teeth Having Based versus Non-Based Amalgam Restorations: A Clinical Study.

DTIC Science & Technology

1983-04-01

Nervous control of blood circulation in dental pulp and the periodontal tissues . p. 139-44. (In Emmelin, N., and Sotterman, Y. eds. Oral physiology. New...using the direct tissue radioautography technique. Oral Surg., Oral Ned., Oral Path., 4:1461-4, Nov. 1951. 132. Scott, H.M. Reduction of sensitivity by...ever being placed underneath his amalgam temporaries. In 1868, "Hills soft stopping" was recommended for use as a palliative underneath amalgam when

Low-intensity lasers, modern filling materials, and bonding systems influence on mineral metabolism of hard dental tissues

NASA Astrophysics Data System (ADS)

Kunin, Anatoly A.; Yesaulenko, I. E.; Zoibelmann, M.; Pankova, Svetlana N.; Ippolitov, Yu. A.; Oleinik, Olga I.; Popova, T. A.; Koretskaya, I. V.; Shumilovitch, Bogdan R.; Podolskaya, Elana E.

2001-10-01

One of the main reasons of low quality filling is breaking Ca-P balance in hard tissues. Our research was done with the purpose of studying the influence of low intensity lasers, diodic radiation, the newest filling and bonding systems on the processes of mineral metabolism in hard dental tissues while filling a tooth. 250 patients having caries and its compli-cations were examined and treated. Our complex research included: visual and instrumental examination, finding out the level of oral cavity hygiene, acid enamel biopsy, scanning electronic microscopy and X-ray spectrum microanalysis. Filling processes may produce a negative effect on mineral metabolism of hard dental tissues the latter is less pronounced when applying fluoride-containing filling materials with bonding systems. It has also been found that bonding dentin and enamel systems are designed for both a better filling adhesion (i.e. mechanical adhesion) and migration of useful microelements present in them by their sinking into hard dental tissues (i.e. chemical adhesion). Our research showed a positive influence of low intensity laser and diodic beams accompanying the use of modern filling and bonding systems on mineral metabolism of hard dental tissues.

[Evaluation of labial surface root filling combined with porcelain dental restoration].

PubMed

Liu, Yuan-qiao; Huang, Zhi-hua; Hu, Huan-yu

2015-04-01

To analyze the effect of porcelain dental restoration combined with labial surface root filling for the anterior teeth. One hundred cases with anterior teeth protrusion treated in our department from January 2010 to January 2014 underwent porcelain dental restoration combined with labial surface root filling. The measurements in cephalometric X-ray films before and after treatment were compared, and porcelain dental appearance and function were evaluated. The data was statistically analyzed with SPSS18.0 software package. After treatment, U1-SN, U1-X, U1-Y were significantly lower than before treatment (P<0.01). U1-L1 was significantly higher after treatment (P<0.01). The incidence of gingivitis after treatment decreased significantly (X(2)=16.2749,P=0.0000<0.01). The excellent rate of outline of porcelain teeth after treatment, correction of protruding anterior teeth, fitting with adjacent teeth and alleviation of deep overbite and deep cover was 96.00%, 95.00%, 98.00% and 91.00%, respectively. Porcelain dental restoration after root canal treatment can effectively improve anterior teeth protrusion and increase the aesthetic appearance, which is worthy of clinical application.

Dental Glass Ionomer Cements as Permanent Filling Materials? —Properties, Limitations Future Trends

PubMed Central

Lohbauer, Ulrich

2009-01-01

Glass ionomer cements (GICs) are clinically attractive dental materials that have certain unique properties that make them useful as restorative and luting materials. This includes adhesion to moist tooth structures and base metals, anticariogenic properties due to release of fluoride, thermal compatibility with tooth enamel, biocompatibility and low toxicity. The use of GICs in a mechanically loaded situation, however, has been hampered by their low mechanical performance. Poor mechanical properties, such as low fracture strength, toughness and wear, limit their extensive use in dentistry as a filling material in stress-bearing applications. In the posterior dental region, glass ionomer cements are mostly used as a temporary filling material. The requirement to strengthen those cements has lead to an ever increasing research effort into reinforcement or strengthening concepts.

Corrosion of dental amalgam and mercury vapor emission in vitro.

PubMed

Moberg, L E

1988-10-01

Amalgam specimens were immersed for 30 days in 1) water, 2) 0.9% NaCl in water, 3) 0.9% NaCl and 10 mM phosphate buffer in water, and 4) 0.9% NaCl, 7.7 mM phosphate, and 6.1 mM citric acid in water. The solutions were stored in stoppered glass tubes. Hg-drops were immersed in solutions 1, 2, and 3. The concentration of mercury vapor in the air above the solutions was measured once a day. After 30 days the amounts of Cu, Zn, Hg, and Ag in the solutions were analyzed by atomic absorption spectrophotometry. The results showed that 0.9% NaCl alone or in combination with the additives increased the amounts of elements released into the solutions. The concentration of Hg0 in the glass tubes increased with the amount of Hg in the solutions, with the exception of solution No. 3, from which significantly less Hg0 evaporated. The results indicate that the composition of the saliva, oral hygiene and dietary factors may be determinants of Hg0 emission from amalgams in the oral cavity.

Radiographic Evaluation of Root Canal Fillings Accomplished by Undergraduate Dental Students

PubMed Central

Yavari, Hamidreza; Samiei, Mohammad; Shahi, Shahriar; Borna, Zahra; Abdollahi, Amir Ardalan; Ghiasvand, Negar; Shariati, Gholamreza

2015-01-01

Introduction: The purpose of this study was to evaluate the radiographic quality of root canal fillings by fourth-, fifth-, and sixth-year undergraduate students at Tabriz Faculty of Dentistry between 2006 and 2012. Methods and Materials: A total of 1183 root canal fillings in 620 teeth were evaluated by two investigators (and in case of disagreement by a third investigator) regarding the presence or absence of under-fillings, over-fillings and perforations. For each tooth, preoperative, working and postoperative radiographs were checked. The Pearson’s chi-square test was used for statistical evaluation of the data. Inter-examiner agreement was measured by Cohen’s kappa (k) values. The level of significance was set at 0.05. Results: Total frequencies of over-filling, under-filling and perforation were 5.6%, 20.4% and 1.9%, respectively. There were significant differences between frequencies of over- and under-fillings (P<0.05). Unacceptable quality, under- and over-fillings were detected in 27.9% of 1183 evaluated canals. Conclusion: The technical quality of root canal therapies performed by undergraduate dental students using step-back preparation and lateral compaction techniques was unacceptable in almost one-fourth of the cases. PMID:25834598

Radiographic evaluation of root canal fillings accomplished by undergraduate dental students.

PubMed

Yavari, Hamidreza; Samiei, Mohammad; Shahi, Shahriar; Borna, Zahra; Abdollahi, Amir Ardalan; Ghiasvand, Negar; Shariati, Gholamreza

2015-01-01

The purpose of this study was to evaluate the radiographic quality of root canal fillings by fourth-, fifth-, and sixth-year undergraduate students at Tabriz Faculty of Dentistry between 2006 and 2012. A total of 1183 root canal fillings in 620 teeth were evaluated by two investigators (and in case of disagreement by a third investigator) regarding the presence or absence of under-fillings, over-fillings and perforations. For each tooth, preoperative, working and postoperative radiographs were checked. The Pearson's chi-square test was used for statistical evaluation of the data. Inter-examiner agreement was measured by Cohen's kappa (k) values. The level of significance was set at 0.05. Total frequencies of over-filling, under-filling and perforation were 5.6%, 20.4% and 1.9%, respectively. There were significant differences between frequencies of over- and under-fillings (P<0.05). Unacceptable quality, under- and over-fillings were detected in 27.9% of 1183 evaluated canals. The technical quality of root canal therapies performed by undergraduate dental students using step-back preparation and lateral compaction techniques was unacceptable in almost one-fourth of the cases.

Reliance on social security benefits by Swedish patients with ill-health attributed to dental fillings: a register-based cohort study.

PubMed

Naimi-Akbar, Aron; Svedberg, Pia; Alexanderson, Kristina; Ekstrand, Jan; Sandborgh-Englund, Gunilla

2012-08-30

Some people attribute their ill health to dental filling materials, experiencing a variety of symptoms. Yet, it is not known if they continue to financially support themselves by work or become reliant on different types of social security benefits. The aim of this study was to analyse reliance on different forms of social security benefits by patients who attribute their poor health to dental filling materials. A longitudinal cohort study with a 13-year follow up. The subjects included were 505 patients attributing their ill health to dental restorative materials, who applied for subsidised filling replacement. They were compared to a cohort of matched controls representing the general population (three controls per patient). Annual individual data on disability pension, sick leave, unemployment benefits, and socio-demographic factors was obtained from Statistics Sweden. Generalized estimating equations were used to test for differences between cohorts in number of days on different types of social security benefits. The cohort of dental filling patients had a significantly higher number of days on sick leave and disability pension than the general population. The test of an overall interaction effect between time and cohort showed a significant difference between the two cohorts regarding both sick leave and disability pension. In the replacement cohort, the highest number of sick-leave days was recorded in the year they applied for subsidised replacement of fillings. While sick leave decreased following the year of application, the number of days on disability pension increased and peaked at the end of follow-up. Ill health related to dental materials is likely to be associated with dependence on social security benefits. Dental filling replacement does not seem to improve workforce participation.

Anisotropic local physical properties of human dental enamel in comparison to properties of some common dental filling materials.

PubMed

Raue, Lars; Hartmann, Christiane D; Rödiger, Matthias; Bürgers, Ralf; Gersdorff, Nikolaus

2014-11-01

A major aspect in evaluating the quality of dental materials is their physical properties. Their properties should be a best fit of the ones of dental hard tissues. Manufacturers give data sheets for each material. The properties listed are characterized by a specific value. This assumes (but does not prove) that there is no direction dependence of the properties. However, dental enamel has direction-dependent properties which additionally vary with location in the tooth. The aim of this paper is to show the local direction dependence of physical properties like the elastic modulus or the thermal expansion in dental hard tissues. With this knowledge the 'perfect filling/dental material' could be characterized. Enamel sections of ∼400-500 μm thickness have been cut with a diamond saw from labial/buccal to palatal/lingual (canine, premolar and molar) and parallel to labial (incisor). Crystallite arrangements have been measured in over 400 data points on all types of teeth with x-ray scattering techniques, known from materials science. X-ray scattering measurements show impressively that dental enamel has a strong direction dependence of its physical properties which also varies with location within the tooth. Dental materials possess only little or no property direction dependence. Therefore, a mismatch was found between enamel and dental materials properties. Since dental materials should possess equal (direction depending) properties, worthwhile properties could be characterized by transferring the directional properties of enamel into a property 'wish list' which future dental materials should fulfil. Hereby the 'perfect dental material' can be characterized.

Particle size analysis of amalgam powder and handpiece generated specimens.

PubMed

Drummond, J L; Hathorn, R M; Cailas, M D; Karuhn, R

2001-07-01

The increasing interest in the elimination of amalgam particles from the dental waste (DW) stream, requires efficient devices to remove these particles. The major objective of this project was to perform a comparative evaluation of five basic methods of particle size analysis in terms of the instrument's ability to quantify the size distribution of the various components within the DW stream. The analytical techniques chosen were image analysis via scanning electron microscopy, standard wire mesh sieves, X-ray sedigraphy, laser diffraction, and electrozone analysis. The DW particle stream components were represented by amalgam powders and handpiece/diamond bur generated specimens of enamel; dentin, whole tooth, and condensed amalgam. Each analytical method quantified the examined DW particle stream components. However, X-ray sedigraphy, electrozone, and laser diffraction particle analyses provided similar results for determining particle distributions of DW samples. These three methods were able to more clearly quantify the properties of the examined powder and condensed amalgam samples. Furthermore, these methods indicated that a significant fraction of the DW stream contains particles less than 20 microm. The findings of this study indicated that the electrozone method is likely to be the most effective technique for quantifying the particle size distribution in the DW particle stream. This method required a relative small volume of sample, was not affected by density, shape factors or optical properties, and measured a sufficient number of particles to provide a reliable representation of the particle size distribution curve.

118. VIEW, LOOKING SOUTHWEST OF GOLD AMALGAMATION ROOM, SHOWING AMALGAMATION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

118. VIEW, LOOKING SOUTHWEST OF GOLD AMALGAMATION ROOM, SHOWING AMALGAMATION BARREL AT CENTER FOREGROUND, BULLION FURNACE IN LARGE HOOD BEHIND IT, AND GOLD RETORT IN BACKGROUND HOOD. NOTE OVERHEAD MONORAIL FOR MATERIALS HANDLING. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

Fracture toughness and fractography of dental cements, lining, build-up, and filling materials.

PubMed

Mueller, H J

1990-06-01

The plane strain fracture toughness (K1c) at 23 degrees C and the fractography of zinc phosphate and zinc polycarboxylate cements, buffered glass ionomer liner, amalgam alloy admixed glass ionomer build-up material, and glass ionomer, microfilled and conventionally filled bis-GMA resin composite filling materials were analyzed by elastic-plastic short-rod and scanning electron microscopy methodologies. Results indicated that significant differences occurred in their K1c's from the lowest to the highest in the following groups of materials, (i) buffered glass ionomer, (ii) zinc phosphate, glass ionomer, zinc polycarboxylate, and alloy mixed glass ionomer, (iii) microfilled resin, and (iv) conventionally filled resin. All materials except the microfilled resin, which fractured via crack jumping, fractured via smooth crack advance. Filler debonding without any crack inhibiting process was related to materials with low K1c values. The incorporation of either buffering compounds or alloy particles into glass ionomer had no beneficial effect upon fracture toughness. This was in contrast to microfilled and conventionally filled resins where either crack blunting or crack pinning processes, respectively, were likely involved with their increased K1c's. For microfilled resin, distinct radial zones positioned around the chevron apex and characterized by plastically deformed deposited material were related to distinct crack jumps that occurred in the load versus displacement behavior. Finally, for the two remaining materials of zinc phosphate and polycarboxylate, particle cleavage and matrix debonding for the former and shear yielding for the latter occurred.

Differences in pediatric dental services under general anesthesia for Medicaid and military dependent children.

PubMed

Johnson, M B; Cappelli, D P; Bradshaw, B S; Mabry, J C

2010-01-01

This study's purpose was to compare pediatric dental services provided for Medicaid and military dependent children to determine if differences in dental treatment choices exist based on site and payment method. Subjects included 120 Medicaid patients at the University of Texas Health Science Center at San Antonio and 120 military dependents at Lackland Air Force Base, Texas. Demographic data and treatment information were abstracted for children younger than 6 years old receiving dental treatment under general anesthesia between 2002 and 2006. Data was analyzed using Wilcoxon rank sum, Kruskal-Wallis, and Fisher's exact tests. The Medicaid recipients were younger (40.2 vs 49.8 months, P<.001) and more likely to be Hispanic (78% vs 30%, P<.001). The means of decayed teeth, fillings, and stainless steel crowns did not differ between sites. Medicaid children received more composite fillings (P<.001), fewer amalgam fillings (P<.001), fewer pulp therapies (P<.001), more extractions (P=.01), and fewer sealants (P<.001). Age and gender did not affect decay rates, but those of Hispanic ethnicity did experience more decay than non-Hispanics (9.5 vs 8.6, P=.02). This study found no difference in the number of less conservative, albeit more costly, procedures performed with Medicaid children at a university compared to military dependents at a military base.

Dental Composite Restorations and Psychosocial Function in Children

PubMed Central

Trachtenberg, Felicia L.; Hauser, Russ; McKinlay, Sonja; Shrader, Peter; Tavares, Mary; Bellinger, David C.

2012-01-01

BACKGROUND AND OBJECTIVE: Resin-based dental materials may intraorally release their chemical components and bisphenol A. The New England Children’s Amalgam Trial found that children randomized to amalgam had better psychosocial outcomes than those assigned to composites for posterior tooth restorations. The objective of this study was to examine whether greater exposure to dental composites is associated with psychosocial problems in children. METHODS: Analysis of treatment-level data from the New England Children’s Amalgam Trial, a 2-group randomized safety trial comparing amalgam with the treatment plan of bisphenol A-glycidyl methacrylate (bisGMA)-based composite and urethane dimethacrylate–based polyacid-modified composite (compomer), among 534 children aged 6 to 10 years at baseline. Psychosocial function at follow-up (n = 434) was measured by using the self-reported Behavior Assessment System for Children (BASC-SR) and parent-reported Child Behavior Checklist (CBCL). RESULTS: Children with higher cumulative exposure to bisGMA-based composite had poorer follow-up scores on 3 of 4 BASC-SR global scales: Emotional Symptoms (β = 0.8, SE = 0.3, P = .003), Clinical Maladjustment (β = 0.7, SE = 0.3, P = .02), and Personal Adjustment (β = –0.8, SE = 0.2, P = .002). Associations were stronger with posterior-occlusal (chewing) surfaces, where degradation of composite was more likely. For CBCL change, associations were not statistically significant. At-risk or clinically significant scores were more common among children with greater exposure for CBCL Total Problem Behaviors (16.3% vs 11.2%, P-trend = .01) and numerous BASC-SR syndromes (eg, ≥13 vs 0 surface-years, Interpersonal Relations 13.7% vs 4.8%, P-trend = .01). No associations were found with compomer, nor with amalgam exposure levels among children randomized to amalgam. CONCLUSIONS: Greater exposure to bisGMA-based dental composite restorations was associated with impaired psychosocial function

Needs Assessment and Telecommunications Cost Benefit Analysis for Army Medical Department Continuing Clinical Education Requirements.

DTIC Science & Technology

1985-04-01

Dentistry 5 0 Medical Teaching Techniques 5 0 Medical Proficiency Training S 5 0 Amalgam Filling Mercury Poisoning Scare Future Trends in Health Care...May). Contemporary Topics For Dieticians and Nutritionists . 1984 Dietary Uptakes. Teleconference Network of Texas. (1984, May-June). Eight contact hours... Teaching Techniques 5 Increaseiig Dental Productivity 5 Amalgam Filling Mercury Poisoning Scare 5 oci’ijitionau Preventive Dentistrv 5 Osseo

SU-E-T-365: Dosimetric Impact of Dental Amalgam CT Image Artifacts On IMRT and VMAT Head and Neck Plans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, N; Young, L; Parvathaneni, U

Purpose: The presence of high density dental amalgam in patient CT image data sets causes dose calculation errors for head and neck (HN) treatment planning. This study assesses and compares dosimetric variations in IMRT and VMAT treatment plans due to dental artifacts. Methods: Sixteen HN patients with similar treatment sites (oropharynx), tumor volume and extensive dental artifacts were divided into two groups: IMRT (n=8, 6 to 9 beams) and VMAT (n=8, 2 arcs with 352° rotation). All cases were planned with the Pinnacle 9.2 treatment planning software using the collapsed cone convolution superposition algorithm and a range of prescription dosemore » from 60 to 72Gy. Two different treatment plans were produced, each based on one of two image sets: (a)uncorrected; (b)dental artifacts density overridden (set to 1.0g/cm{sup 3}). Differences between the two treatment plans for each of the IMRT and VMAT techniques were quantified by the following dosimetric parameters: maximum point dose, maximum spinal cord and brainstem dose, mean left and right parotid dose, and PTV coverage (V95%Rx). Average differences generated for these dosimetric parameters were compared between IMRT and VMAT plans. Results: The average absolute dose differences (plan a minus plan b) for the VMAT and IMRT techniques, respectively, caused by dental artifacts were: 2.2±3.3cGy vs. 37.6±57.5cGy (maximum point dose, P=0.15); 1.2±0.9cGy vs. 7.9±6.7cGy (maximum spinal cord dose, P=0.026); 2.2±2.4cGy vs. 12.1±13.0cGy (maximum brainstem dose, P=0.077); 0.9±1.1cGy vs. 4.1±3.5cGy (mean left parotid dose, P=0.038); 0.9±0.8cGy vs. 7.8±11.9cGy (mean right parotid dose, P=0.136); 0.021%±0.014% vs. 0.803%±1.44% (PTV coverage, P=0.17). Conclusion: For the HN plans studied, dental artifacts demonstrated a greater dose calculation error for IMRT plans compared to VMAT plans. Rotational arcs appear on the average to compensate dose calculation errors induced by dental artifacts. Thus, compared to VMAT

Bond strength of repaired amalgam restorations.

PubMed

Rey, Rosalia; Mondragon, Eduardo; Shen, Chiayi

2015-01-01

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.

Single crowns versus conventional fillings for the restoration of root filled teeth.

PubMed

Fedorowicz, Zbys; Carter, Ben; de Souza, Raphael Freitas; Chaves, Carolina de Andrade Lima; Nasser, Mona; Sequeira-Byron, Patrick

2012-05-16

Endodontic treatment, involves removal of the dental pulp and its replacement by a root canal filling. Restoration of root filled teeth can be challenging due to structural differences between vital and non-vital root filled teeth. Direct restoration involves placement of a restorative material e.g. amalgam or composite directly into the tooth. Indirect restorations consist of cast metal or ceramic (porcelain) crowns. The choice of restoration depends on the amount of remaining tooth which may influence long term survival and cost. The comparative in service clinical performance of crowns or conventional fillings used to restore root filled teeth is unclear. To assess the effects of restoration of endodontically treated teeth (with or without post and core) by crowns versus conventional filling materials. We searched the following databases: the Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE via OVID, EMBASE via OVID, CINAHL via EBSCO, LILACS via BIREME and the reference lists of articles as well as ongoing trials registries.There were no restrictions regarding language or date of publication. Date of last search was 13 February 2012. Randomised controlled trials (RCTs) or quasi-randomised controlled trials in participants with permanent teeth which have undergone endodontic treatment. Single full coverage crowns compared with any type of filling materials for direct restoration, as well as indirect partial restorations (e.g. inlays and onlays). Comparisons considered the type of post and core used (cast or prefabricated post), if any. Two review authors independently assessed trial quality and extracted data. One trial judged to be at high risk of bias due to missing outcome data, was included. 117 participants with a root filled premolar tooth restored with a carbon fibre post, were randomised to either a full coverage metal-ceramic crown or direct adhesive composite restoration. At 3 years there was no reported difference between the non

Maternal dental history and child’s birth outcome and early cognitive development

PubMed Central

Daniels, JL; Rowland, AS; Longnecker, MP; Crawford, P; Golding, J

2013-01-01

Summary 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 might 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 1991–1992. 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 (β=14.7, p=0.4), but was associated with slightly increased odds of having a term, low birthweight baby (OR 1.9, 95%CI 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. PMID:17697075

Full in-vitro analyses of new-generation bulk fill dental composites cured by halogen light.

PubMed

Tekin, Tuçe Hazal; Kantürk Figen, Aysel; Yılmaz Atalı, Pınar; Coşkuner Filiz, Bilge; Pişkin, Mehmet Burçin

2017-08-01

The objective of this study was to investigate the full in-vitro analyses of new-generation bulk-fill dental composites cured by halogen light (HLG). Two types' four composites were studied: Surefill SDR (SDR) and Xtra Base (XB) as bulk-fill flowable materials; QuixFill (QF) and XtraFill (XF) as packable bulk-fill materials. Samples were prepared for each analysis and test by applying the same procedure, but with different diameters and thicknesses appropriate to the analysis and test requirements. Thermal properties were determined by thermogravimetric analysis (TG/DTG) and differential scanning calorimetry (DSC) analysis; the Vickers microhardness (VHN) was measured after 1, 7, 15 and 30days of storage in water. The degree of conversion values for the materials (DC, %) were immediately measured using near-infrared spectroscopy (FT-IR). The surface morphology of the composites was investigated by scanning electron microscopes (SEM) and atomic-force microscopy (AFM) analyses. The sorption and solubility measurements were also performed after 1, 7, 15 and 30days of storage in water. In addition to his, the data were statistically analyzed using one-way analysis of variance, and both the Newman Keuls and Tukey multiple comparison tests. The statistical significance level was established at p<0.05. According to the ISO 4049 standards, all the tested materials showed acceptable water sorption and solubility, and a halogen light source was an option to polymerize bulk-fill, resin-based dental composites. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of the push-out shear bond strength of four types of glass ionomers when used to bond amalgam: An in vitro study

PubMed Central

Mathew, Vinod Babu; Ramachandran, S; Indira, R; Shankar, P

2011-01-01

Background: Dental amalgam is the primary direct posterior restorative material used worldwide, but it have certain shortcomings due to the lack of adhesiveness to the cavity. The introduction of the concept of bonded amalgam helped improve the use of amalgam as a restorative material. Aim: Evaluation of the comparative push-out shear bond strength of four types of conventional glass ionomers used to bond amalgam to tooth in simulated class I situations. Materials and Methods: Four chemical cure glass ionomers are used: GC Fuji I, GC Fuji II, GC Fuji III and GC Fuji VII, and are compared with unbonded amalgam. The push-out bond strength was tested using the Instron Universal Testing Machine at a crosshead speed of 0.5 mm/min. Statistical Analysis: One-way ANOVA and post hoc Bonferroni tests were used to analyze the data. Results: The results showed that the use of glass ionomer to bond amalgam resulted in an increase in the bond strength of amalgam. The Type VII glass ionomer showed the highest bond strength in comparison with the other glass ionomers. Conclusions: Conventional glass ionomer bonds to amalgam and shows a beneficial increase in the bond strength of the restoration in comparison with unbonded amalgam. PMID:22144798

[Cermet cements for milk tooth fillings. Preliminary results].

PubMed

Hickel, R; Petschelt, A; Voss, A

1989-06-01

106 Ketac-Silver fillings in deciduous molars were reevaluated after 1 to 3.3 years, i.e. 25 month on the average. About 90% of 50 occlusal fillings and about 84% of 56 multisurface restorations were unchanged. Without claiming statistical evidence for their conclusiveness, we consider these results as an indication that cermet cements are a useful alternative to amalgam fillings in deciduous teeth, particularly since the life of these fillings is limited to the time until the milk tooth is physiologically lost.

A comparative study of plaque mutans streptococci levels in children receiving glass ionomer cement and amalgam restorations.

PubMed

Ertuğrul, Fahinur; Eltem, Rengin; Eronat, Cemal

2003-01-01

The restorative materials amalgam (Standalloy F) and glass ionomer cements (Chelon Silver) were comparatively investigated to determine the number of mutans streptococci Saliva and plaque were collected from patients before and 40 days after the insertion of their restorations. Total bateria and mutans streptococci counts were found to be statistically significantly reduced when compared with the prerestoration counts in the saliva samples (P<0.001). Microbiological analysis of the dental plaque showed that the number of mutans streptococci in the glass ionomer cements was significantly lower than in the amalgam restorations (P<0.001). This study showed that silver glass ionomer cements inhibited the growth of mutans streptococci.

Clinical and laboratory evaluation of microstructural changes in the physical, mechanical and chemical properties of dental filling materials under the influence of an electromagnetic field.

PubMed

Moiseeva, Natalia S; Kunin, Anatoly A

2018-03-01

Restorative filling materials used for dental caries prevention and treatment consist of various components including monomers or oligomers, which play a significant role in forming the main structure of these materials, as well as in characterising their physical, mechanical and chemical properties. The necessity for the development and improvement of structural characteristics of polymeric dental filling materials intended for caries prevention and their life duration increase served as the initiating factor of our research. According to the research purpose and challenges, we studied the changes in the physical, mechanical and chemical properties of composite filling materials with and without electromagnetic field influence. The investigations in vivo include the study of microstructural features of polymeric filling materials by scanning electron microscopy (SEM) and the investigations in vitro include the study of sealed and extracted human teeth chips by using X-ray spectral analysis. We also evaluated the changes in the strength characteristics of dental filling materials with and without electromagnetic field influence. The analysis of the obtained data indicates the presence of structural changes in polymeric dental filling materials, including the material microstructure condensation confirmed by the SEM results, an increase in the strength and adhesion characteristics and certain regularities of the chemical elemental composition concentration change in the area of hard tooth tissue and dental filling material. These scientific data will provide tooth caries prevention and promote the increase of treatment quality.

Ablation by-products of dental materials from the Er:YAG laser and the dental handpiece

NASA Astrophysics Data System (ADS)

Wigdor, Harvey A.; Visuri, Steven R.; Walsh, Joseph T., Jr.

1995-05-01

Recently there has been much interest in lasers and their potential use to replace the dental drill. The research has been directed towards vital dental tissues. It must be understood that any laser to be used in dentistry which will replace the dental drill must also ablate and remove existing dental materials. Some concern exists about the ablation products when the Er:YAG laser is used to ablate dental materials. It is incumbent on the professionals using these lasers to understand the materials being produced by these lasers and protect themselves and their patients from possible toxic products. It is the intent of this paper to evaluate the products produced by the ablation of both dental amalgam and composite dental restorative materials and compare them with those produced by the traditional dental handpiece (drill).

'It's good enough': Swedish general dental practitioners on reasons for accepting substandard root filling quality.

PubMed

Dahlström, L; Lindwall, O; Rystedt, H; Reit, C

2018-04-01

The concept of 'good enough' is central and necessary in the assessment of root filling quality. The aim was to explore the concept by analysing reasons and arguments for the acceptance or rejection of substandard root filling quality as reported by general dental practitioners (GDPs) in Sweden. The study was designed as a qualitative and exploratory study based on seven videotaped focus group interviews analysed by means of qualitative content analysis. Thirty-three GDPs employed in the Public Dental Health Service in Gothenburg, Sweden, participated (4-6 GDPs/interview). In all, nine predetermined questions were followed. Before each focus group, the participants received radiographs of 37 root fillings and were asked to assess the root filling quality. The three cases representing the most divergent assessments served as a basis for the discussion. The cases were presented without clinical information; the dentists would relate to the cases as being just root filled by themselves. The radiographs did not provide a sufficient basis for decisions on whether or not to accept the root filling. This study emphasized that dentists did not primarily look for these arguments in the technical details of the root filling per se, but instead, they considered selected features of the contextual situation. The GDPs constantly introduced relevant 'ad hoc considerations' to account for the decisions they made. These contextual considerations were related to aspects of pulpal and periapical disease, risks (e.g. technical complications) or to consumed resources (personal and/or economic). It was obvious that the concept of 'good enough' does not exist as a general formula ready to be applied in particular situations. Instead, it is necessarily and irremediably tied to contextual properties that emerge from case to case. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Dental associations with blood mercury in pregnant women.

PubMed

Golding, Jean; Steer, Colin D; Gregory, Steven; Lowery, Tony; Hibbeln, Joseph R; Taylor, Caroline M

2016-06-01

There is curiosity concerning the source of mercury that is absorbed into the mother's blood and which may affect the developing fetus. This study therefore sets out to determine the extent to which dental amalgam (DA) may contribute to total blood mercury (TBHg) levels of pregnant women in the UK. Whole blood samples and information on diet and socio-demographic factors were collected from pregnant women (n = 4484) enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). The whole blood samples were assayed for total mercury levels using inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS), and the women were retrospectively asked about features of their dental care during the pregnancy. Linear regression was used to estimate the relative contributions of DA to TBHg levels (log-transformed) based on R(2) values, compared to the results from dietary and socio-demographic variables. The contribution to the variance of the mothers' TBHg levels by dental variables was 6.47%, a figure comparable to the 8.75% shown for seafood consumption in this population. Dietary and dental variables explained 20.16% of the variance, with socio-demographic variables contributing only a further 3.40%. The number of amalgams in the mouth at the start of pregnancy accounted for most of the variance in dental variables. Dental amalgam contributes a comparable amount of variance in TBHg to seafood consumption in this population. However, because the measures of DA exposure were imprecise, these findings are likely to be an underestimate. There is no evidence to date in the literature that fetal exposures to mercury from maternal DAs have adverse effects on the developing child, but long-term studies are warranted. © 2015 The Authors. Community Dentistry and Oral Epidemiology Published by John Wiley & Sons Ltd.

Factors relating to usage patterns of amalgam and resin composite for posterior restorations--a prospective analysis.

PubMed

Khalaf, Mai E; Alomari, Qasem D; Omar, Ridwaan

2014-07-01

This study prospectively analyzed the use of amalgam and resin composite posterior restorations placed by general dentists in relation to dentist, patient and cavity factors. One thousand posterior restorations placed by a representative sample of general dentists working in the Ministry of Health (MOH), Kuwait, during routine clinical practice were included. Information about the restorations was recorded using a survey questionnaire. Descriptive statistics and multivariate logistic regression analysis were used to determine the factors associated with the use of amalgam versus tooth coloured restoratives. Dentists chose amalgam for 30.8% of the 1000 restorations. Dentists with longer work experience (>15 years) were more likely to choose amalgam (OR=2.61, 95% CI=1.06, 6.40). Younger dentists (≤30 years) were less likely to choose amalgam (OR=0. 45, 95% CI=0.26, 0.77). Amalgam was more likely to be chosen for patients with poor oral hygiene (OR=1.58, 95% CI=1.08, 2.32) and a higher number (≥4) of restorations (OR=1.44, 95% CI=1.07, 1.94) with large cavity sizes (OR=6.33, 95% CI=3.88, 10.32). Tooth-coloured restorations were more likely to be chosen for cavities of smaller sizes. The use of resin composite materials as the dominant choice among dentists in Kuwait reflects the trend worldwide. Nevertheless, clinicians still find a use for amalgam in posterior load-bearing teeth and in the high-caries risk population. The findings give insight into factors influencing material usage under different clinical conditions and provides information about the perceived deficiencies or shortcomings of resin composite materials in a general dental practice setting. This information can be useful for identifying perceived barriers to the usage of newer restorative materials and finding ways to overcome them. Copyright © 2014 Elsevier Ltd. All rights reserved.

Extension and Density of Root Fillings and Post-operative Apical Radiolucencies in the Veterans Affairs Dental Longitudinal Study

PubMed Central

Zhong, Yan; Chasen, Joel; Yamanaka, Ryan; Garcia, Raul; Kaye, Elizabeth Krall; Kaufman, Jay S; Cai, Jianwen; Wilcosky, Tim; Trope, Martin; Caplan, Daniel J

2008-01-01

We evaluated the association between radiographically-assessed extension and density of root canal fillings and post-operative apical radiolucencies (AR) using data from 288 participants in the Veterans Affairs Dental Longitudinal Study. Study subjects were not VA patients; all received their medical and dental care in the private sector. Generalized Estimating Equations were used to account for multiple teeth within subjects and to control for covariates of interest. Defective root filling density was associated with increased odds of post-operative AR among teeth with no pre-operative AR (Odds Ratio=3.0, 95%CI=1.3–7.1), though pre-operative AR was the strongest risk factor for post-operative AR (Odds Ratio=29.2, 95%CI=13.6–63.0 among teeth with ideal density). Compared to well-extended root fillings, neither over- nor under-extended root fillings separately were related to post-operative AR, but when those two categories were collapsed into one “poorly-extended” category, poor extension was related to post-operative AR (Odds Ratio=1.8, 95%CI=1.1–3.2). PMID:18570982

Effect of radiofrequency radiation from Wi-Fi devices on mercury release from amalgam restorations.

PubMed

Paknahad, Maryam; Mortazavi, S M J; Shahidi, Shoaleh; Mortazavi, Ghazal; Haghani, Masoud

2016-01-01

Dental amalgam is composed of approximately 50% elemental mercury. Despite concerns over the toxicity of mercury, amalgam is still the most widely used restorative material. Wi-Fi is a rapidly using local area wireless computer networking technology. To the best of our knowledge, this is the first study that evaluates the effect of exposure to Wi-Fi signals on mercury release from amalgam restorations. Standard class V cavities were prepared on the buccal surfaces of 20 non-carious extracted human premolars. The teeth were randomly divided into 2 groups (n = 10). The control group was stored in non-environment. The specimens in the experimental groups were exposed to a radiofrequency radiation emitted from standard Wi Fi devices at 2.4 GHz for 20 min. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. The concentration of mercury in the artificial saliva in the groups was evaluated by using a cold-vapor atomic absorption Mercury Analyzer System. The independent t test was used to evaluate any significant differences in mercury release between the two groups. The mean (±SD) concentration of mercury in the artificial saliva of the Wi-Fi exposed teeth samples was 0.056 ± .025 mg/L, while it was only 0.026 ± .008 mg/L in the non-exposed control samples. This difference was statistically significant (P =0.009). Exposure of patients with amalgam restorations to radiofrequency radiation emitted from conventional Wi-Fi devices can increase mercury release from amalgam restorations.

Relative value of dental procedures.

PubMed

Tuominen, R; Tuominen, M

1994-10-01

This study was conducted to develop a relative value method for dental procedures, and to evaluate the differences in values assigned by private and public sector dentists. Samples of 90 general practitioners and 120 clinical specialists were systematically drawn to represent all actively working Finnish dentists. The dentists were asked to assess the required time and know-how for performing various procedures compared to performing a two-surface amalgam filling (AF2). At the end, the dentists were asked to divide the value of 200 between time and know-how for the reference procedure (AF2). These figures were then utilized to calculate the average relative value for each procedure. Private practitioners' weighted relative values were 55.3% higher than the prices, and among public sector dentists they were 27.9% higher. Overall, know-how constituted more of the total value of the procedures than did time. Private practitioners' time assessments correlated well (r = 0.72-0.95) with the recommended prices. However, significant differences were often observed both in time and know-how assessments of individual procedures. Both time and know-how seem to be important factors when determining values for dental services. For evaluation of the value of output in the private sector, the use of prices is justified. However, when the productivity of non-profit dental offices is evaluated, a value system which is not based on market prices is needed.

Antimicrobial properties of conventional restorative filling materials and advances in antimicrobial properties of composite resins and glass ionomer cements-A literature review.

PubMed

Farrugia, Cher; Camilleri, Josette

2015-04-01

It has been reported that complete caries removal from cavities during restoration of teeth is difficult. Furthermore with the tissue saving approach it is expected that more of the saved affected tissue will possibly harbor more residual bacteria. Antimicrobial restorative filling materials would be ideal to prevent the spread of caries after completion of tooth restoration, thus preventing recurrent decay and eventually restoration failure. This paper reviews the literature on the antimicrobial properties of dental restorative filling materials. Pubmed searches on the antibacterial properties of restorative materials were carried out. Keywords were chosen to assess antibacterial properties of conventional filling materials. Methods of introducing antimicrobial agents in restorative materials were also reviewed together with the methodology used to assess antimicrobial activity. 174 articles from 1983 till 2014 were included. Adhesive materials have decreased antimicrobial activity when compared to amalgams and zinc oxides. Several techniques have been employed in order to increase the antimicrobial activity of restorative materials. Although antimicrobial activity of restorative materials is important, the introduction of antimicrobial agents/techniques should not be at the expense of other material properties. Environmental changes within a material may affect the bacterial response to the antimicrobial. Bacterial adhesion to the restorative materials should be assessed. Long term assessment of antimicrobial activity is important and is clinically relevant. The use of antimicrobial dental materials is important unless such characteristics are gained to the detriment of other material properties. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

State-of-the-art techniques in operative dentistry: contemporary teaching of posterior composites in UK and Irish dental schools.

PubMed

Lynch, C D; Frazier, K B; McConnell, R J; Blum, I R; Wilson, N H F

2010-08-14

Advances of composite systems and their application have revolutionised the management of posterior teeth affected by caries, facilitating a minimally invasive approach. Previous surveys have indicated that the teaching of posterior composites within dental schools was developing, albeit not keeping pace with clinical evidence and the development of increasingly predictable techniques and materials. Concurrently, surveys of dental practice indicate that dental amalgam still predominates as the 'material of choice' for the restoration of posterior teeth within UK general dental practice. In light of such considerations, the aim of this study was to investigate current teaching of posterior composites in Irish and UK dental schools. An online questionnaire which sought information in relation to the current teaching of posterior composites was developed and distributed to the 17 established Irish and UK dental schools with undergraduate teaching programmes in late 2009. Completed responses were received from all 17 schools (response rate = 100%). All 17 schools taught the placement of occlusal and two-surface occlusoproximal composites in premolar and permanent molar teeth. Two schools did not teach placement of three-surface occlusoproximal composites in either premolars or molars. In their preclinical courses, ten schools taught posterior composites before teaching dental amalgams. Fifty-five percent of posterior restorations placed by dental students were of composite (range = 10-90%) and 44% amalgam (range = 10-90%), indicating an increase of 180% in the numbers of posterior composites placed over the past five years. Diversity was noted in the teaching of clinical techniques and students at different schools are trained with different composites and bonding systems. Some cause for concern was noted in the teaching of certain techniques that were not in keeping with existing best evidence, such as the teaching of transparent matrix bands and light

Exposures of dental professionals to elemental mercury and methylmercury.

PubMed

Goodrich, Jaclyn M; Chou, Hwai-Nan; Gruninger, Stephen E; Franzblau, Alfred; Basu, Niladri

2016-01-01

Mercury (Hg) exposure, a worldwide public health concern, predominantly takes two forms--methylmercury from fish consumption and elemental Hg from dental amalgam restorations. We recruited 630 dental professionals from an American Dental Association meeting to assess Hg body burden and primary sources of exposure in a dually exposed population. Participants described occupational practices and fish consumption patterns via questionnaire. Hg levels in biomarkers of elemental Hg (urine) and methylmercury (hair and blood) were measured with a Direct Mercury Analyzer-80 and were higher than the general US population. Geometric means (95% CI) were 1.28 (1.19-1.37) μg/l in urine, 0.60 (0.54-0.67) μg/g in hair and 3.67 (3.38-3.98) μg/l in blood. In multivariable linear regression, personal amalgams predicted urine Hg levels along with total years in dentistry, amalgams handled, working hours and sex. Fish consumption patterns predicted hair and blood Hg levels, which were higher among Asians compared with Caucasians. Five species contributed the majority of the estimated Hg intake from fish--swordfish, fresh tuna, white canned tuna, whitefish and king mackerel. When studying populations with occupational exposure to Hg, it is important to assess environmental exposures to both elemental Hg and methylmercury as these constitute a large proportion of total exposure.

Exposures of Dental Professionals to Elemental Mercury and Methylmercury

PubMed Central

Goodrich, Jaclyn M.; Chou, Hwai-Nan; Gruninger, Stephen E.; Franzblau, Alfred; Basu, Niladri

2015-01-01

Mercury (Hg) exposure, a worldwide public health concern, predominantly takes two forms – methylmercury from fish consumption and elemental Hg from dental amalgam restorations. We recruited 630 dental professionals from an American Dental Association meeting to assess Hg body burden and primary sources of exposure in a dually-exposed population. Participants described occupational practices and fish consumption patterns via questionnaire. Mercury levels in biomarkers of elemental Hg (urine) and methylmercury (hair, blood) were measured with a Direct Mercury Analyzer-80 and were higher than the general U.S. population. Geometric means (95% CI) were 1.28 (1.19–1.37) µg/L in urine, 0.60 (0.54–0.67) µg/g in hair, and 3.67 (3.38–3.98) µg/L in blood. In multivariable linear regression, personal amalgams predicted urine Hg levels along with total years in dentistry, amalgams handled, working hours, and sex. Fish consumption patterns predicted hair and blood Hg levels which were higher among Asians compared with Caucasians. Five species contributed the majority of the estimated Hg intake from fish - swordfish, fresh tuna, white canned tuna, whitefish, and king mackerel. When studying populations with occupational exposure to Hg, it is important to assess environmental exposures to both elemental Hg and methylmercury as these constitute a large proportion of total exposure. PMID:26329138

Novel Amalgams for In-Space Parts Fabrication

NASA Technical Reports Server (NTRS)

Cochran, Calvin; VanHoose, James R.; Grugel, Richard N.

2012-01-01

Sound amalgams can be fabricated by substituting Ga-In liquid for mercury; Cu-coated steel fibers bond well with the amalgam components. Inclusion of steel fibers significantly improved mechanical properties. An application scenario utilizing amalgams for in-space parts fabrication and repair was suggested. Procedure and materials need to be optimized

Success of Dental Treatments under Behavior Management, Sedation and General Anesthesia.

PubMed

Blumer, Sigalit; Costa, Liora; Peretz, Benjamin

To present comparative study aims to assist the practitioner to choose between behavior modification (BM) techniques, pharmacologic sedation (N 2 O-O 2 alone or combined with midazolam 0.5 mg/ kg) or routine general anesthesia (GA) for the most successful approach in enabling pediatric dental care. Dental records of 56 children treated in a university dental clinic between 2006-2016 were reviewed, and data on age, gender, required treatment (amalgam restorations, composite restorations, pulpotomy, and stainless steel crowns [SSC]), treatment approaches and therapeutic success at final follow-up were retrieved. Treatment under GA had the best success rates compared to both BM and pharmacologic sedation. N 2 O-O 2 alone had a 6.1-fold greater risk of failure compared to N 2 O-O 2 +midazolam (p- <0.008). Amalgam restorations had a 2.61-fold greater risk of failure than SSC (p- <0.008). The GA mode yielded significantly greater success than the N 2 O-O 2 mode alone. There were no significant differences in success rates between GA and combined midazolam 0.5 mg/kg+N 2 O-O 2 . When choosing restoration material, it is important to remember the high success rate of SSC compared to amalgam restoration.

METHOD AND APPARATUS FOR DETERMINING AMALGAM DECOMPOSITION RATE

DOEpatents

Johnson, R.W.; Wright, C.C.

1962-04-24

A method and apparatus for measuring the rate at which an amalgam decomposes in contact with aqueous solutions are described. The amalgam and an aqueous hydroxide solution are disposed in an electrolytic cell. The amalgam is used as the cathode of the cell, and an electrode and anode are disposed in the aqueous solution. A variable source of plating potential is connected across the cell. The difference in voltage between the amalgam cathode and a calibrated source of reference potential is used to control the variable source to null the difference in voltage and at the same time to maintain the concentration of the amalgam at some predetermined constant value. The value of the current required to maintain this concentration constant is indicative of the decomposition rate of the amalgam. (AEC)

Dental Stem Cell Migration on Pulp Ceiling Cavities Filled with MTA, Dentin Chips, or Bio-Oss

PubMed Central

Lymperi, Stefania; Taraslia, Vasiliki; Tsatsoulis, Ioannis N.; Samara, Athina; Agrafioti, Anastasia; Anastasiadou, Ema; Kontakiotis, Evangelos

2015-01-01

MTA, Bio-Oss, and dentin chips have been successfully used in endodontics. The aim of this study was to assess the adhesion and migration of dental stem cells on human pulp ceiling cavities filled with these endodontic materials in an experimental model, which mimics the clinical conditions of regenerative endodontics. Cavities were formed, by a homemade mold, on untouched third molars, filled with endodontic materials, and observed with electron microscopy. Cells were seeded on cavities' surface and their morphology and number were analysed. The phenomenon of tropism was assessed in a migration assay. All three materials demonstrated appropriate microstructures for cell attachment. Cells grew on all reagents, but they showed a differential morphology. Moreover, variations were observed when comparing cells numbers on cavity's filling versus the surrounding dentine disc. The highest number of cells was recorded on dentin chips whereas the opposite was true for Bio-Oss. This was confirmed in the migration assay where a statistically significant lower number of cells migrated towards Bio-Oss as compared to MTA and dentin chips. This study highlights that MTA and dentin chips have a greater potential compared to Bio-Oss regarding the attraction of dental stem cells and are good candidates for bioengineered pulp regeneration. PMID:26146613

An investigation of the microstructure and mechanical properties of electrochemically coated Ag(4)Sn dental alloy particles condensed in vitro

NASA Astrophysics Data System (ADS)

Marquez, Jose Antonio

As part of the ongoing scientific effort to develop a new amalgam-like material without mercury, a team of metallurgists and electrochemists at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, announced in 1993 the development of a new Ag-Sn dental alloy system without mercury that sought to replace conventional dental amalgams. They used spherical Ag3Sn and Ag4Sn intermetallic dental alloy particles, commonly used in conventional dental alloys, and coated them with electrodeposited silver with newly-developed electrolytic and immersion techniques. The particles had relatively pure silver coatings that were closely adherent to the intermetalfic cores. These silver-coated particles, due to silver's plasticity at room temperature, were condensed into PlexiglasRTM molds with the aid of an acidic surface activating solution (HBF4) and a mechanical condensing device, producing a metal-matrix composite with Ag3,4Sn filler particles surrounded by a cold-welded silver matrix. Since silver strain hardens rather easily, the layers had to be condensed in less than 0.5 mm increments to obtain a dense structure. Mechanical testing at NIST produced compressive strength values equal to or greater than those of conventional dental amalgams. Because of its potential for eliminating mercury as a constituent in dental amalgam, this material created a stir in dental circles when first developed and conceivably could prove to be a major breakthrough in the field of dental restoratives. To date, the chief impediments to its approval for human clinical applications by the Food and Drug Administration are the potentially-toxic surface activating solution used for oxide reduction, and the high condensation pressures needed for cold welding because of the tendency for silver to strain harden. In this related study, the author, who has practiced general dentistry for 25 years, evaluates some of the mechanical and microstructural properties of these

Improvement of Cheilitis granulomatosa after Dental Treatment

PubMed Central

Sasaki, Ryosuke; Suzuki, Kayoko; Hayashi, Teppei; Inasaka, Hiroshi; Matsunaga, Kayoko

2011-01-01

A 38-year-old male suffered from swelling of the lower lip for 3 months. Neither facial nerve palsy nor fissuring of the tongue was present. Histological examination of a biopsy taken from the lower lip revealed non-caseous epithelioid cell granulomas, suggestive of cheilitis granulomatosa. Patch testing revealed positive reactions to mercury chloride and amalgam. His symptoms markedly improved 3 months after treatment of the apical periodontitis and replacement of dental crowns. As his dental crowns did not contain mercury, we believe that the cheilitis granulomatosa may have been related to the focal dental infection. PMID:21941479

Effects of high temperature on different restorations in forensic identification: Dental samples and mandible

PubMed Central

Patidar, Kalpana A; Parwani, Rajkumar; Wanjari, Sangeeta

2010-01-01

Introduction: The forensic odontologist strives to utilize the charred human dentition throughout each stage of dental evaluation, and restorations are as unique as fingerprints and their radiographic morphology as well as the types of filling materials are often the main feature for identification. The knowledge of detecting residual restorative material and composition of unrecovered adjacent restoration is a valuable tool-mark in the presumptive identification of the dentition of a burned victim. Gold, silver amalgam, silicate restoration, and so on, have a different resistance to prolonged high temperature, therefore, the identification of burned bodies can be correlated with adequate qualities and quantities of the traces. Most of the dental examination relies heavily on the presence of the restoration as well as the relationship of one dental structure to another. This greatly narrows the research for the final identification that is based on postmortem data. Aim: The purpose of this study is to examine the resistance of teeth and different restorative materials, and the mandible, to variable temperature and duration, for the purpose of identification. Materials and Methods: The study was conducted on 72 extracted teeth which were divided into six goups of 12 teeth each based on the type of restorative material. (Group 1 - unrestored teeth, group 2 - teeth restored with Zn3(PO4)2, group 3 - with silver amalgam, group 4 with glass ionomer cement, group 5 - Ni-Cr-metal crown, group 6 - metal ceramic crown) and two specimens of the mandible. The effect of incineration at 400°C (5 mins, 15 mins, 30 mins) and 1100°C (15 mins) was studied. Results: Damage to the teeth subjected to variable temperatures and time can be categorized as intact (no damage), scorched (superficially parched and discolored), charred (reduced to carbon by incomplete combustion) and incinerated (burned to ashes). PMID:21189989

The impacts of dental filling materials on RapidArc treatment planning and dose delivery: Challenges and solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mail, Noor; Al-Ghamdi, S.; Saoudi, A.

Purpose: The presence of high-density material in the oral cavity creates dose perturbation in both downstream and upstream directions at the surfaces of dental filling materials (DFM). In this study, the authors have investigated the effect of DFM on head and neck RapidArc treatment plans and delivery. Solutions are proposed to address (1) the issue of downstream dose perturbation, which might cause target under dosage, and (2) to reduce the upstream dose from DFM which may be the primary source of mucositis. In addition, an investigation of the clinical role of a custom-made plastic dental mold/gutter (PDM) in sparing themore » oral mucosa and tongue reaction is outlined.Methods: The influence of the dental filling artifacts on dose distribution was investigated using a geometrically well-defined head and neck intensity modulated radiation therapy (IMRT) verification phantom (PTW, Freiberg, Germany) with DFM inserts called amalgam, which contained 50% mercury, 25% silver, 14% tin, 8% copper, and 3% other trace metals. Three RapidArc plans were generated in the Varian Eclipse System to treat the oral cavity using the same computer tomography (CT) dataset, including (1) a raw CT image, (2) a streaking artifacts region, which was replaced with a mask of 10 HU, and (3) a 2 cm-thick 6000 HU virtual filter [a volume created in treatment planning system to compensate for beam attenuation, where the thickness of this virtual filter is based on the measured percent depth dose (PDD) data and Eclipse calculation]. The dose delivery for the three plans was verified using Gafchromic-EBT2 film measurements. The custom-made PDM technique to reduce backscatter dose was clinically tested on four head and neck cancer patients (T3, N1, M0) with DFM, two patients with PDM and the other two patients without PDM. The thickness calculation of the PDM toward the mucosa and tongue was purely based on the measured upstream dose. Patients’ with oral mucosal reaction was clinically

A 4 year follow-up study of alveolar bone height influenced by two dissimilar Class II amalgam restorations.

PubMed

Fisher, D; Markitziu, A; Fishel, D; Brayer, L

1984-07-01

Fifty-four paired, approximal amalgam fillings, extended (E) versus unextended (NE) were placed in forty-three patients and followed up to 4 years. Yearly measurements between the alveolar crest and (a) the apical margin of the fillings (E, NE), and (b) the cemento-enamel junction of the control group, were performed using bite-wing radiographs joined to a translucent grid magnified ten-fold. The rate of alveolar crest resorption was similar for the control (C) and the unextended filling (NE) and reached 0.45 mm after 4 years of follow-up. The resorption of the alveolar crest under the extended (E) filling was significantly higher and reached 0.80 mm after 4 years (P less than 0.001).

Improved orthodontic bonding to silver amalgam. Part 2. Lathe-cut, admixed, and spherical amalgams with different intermediate resins.

PubMed

Büyükyilmaz, T; Zachrisson, B U

1998-08-01

Flat rectangular tabs (n = 270) prepared from spherical (Tytin), admixed (Dispersalloy) or lathe-cut amalgam (ANA 2000) were subjected to aluminum oxide sandblasting with either 50-mu or 90-mu abrasive powder. Mandibular incisor edgewise brackets were bonded to these tabs. An intermediate resin was used, either All-Bond 2 Primers A + B or a 4-META product--Amalgambond Plus (AP) or Reliance Metal Primer (RMP)--followed by Concise. All specimens were stored in water at 37 degrees C for 24 hours and thermocycled 1000 times from 5 degrees C to 55 degrees C and back before tensile bond strength testing. The bond strength of Concise to etched enamel of extracted, caries-free premolars was used as a control. Bond failure sites were classified using a modified adhesive remnant index (ARI) system. Results were expressed as mean bond strength with SD, and as a function relating the probability of bond failure to stress by means of Weibull analysis. Mean tensile bond strength in the experimental groups ranged from 2.9 to 11.0 MPa--significantly weaker than the control sample (16.0 MPa). Bond failure invariably occurred at the amalgam/adhesive interface. The strongest bonds were created to the spherical and lathe-cut amalgams (range 6.8 to 11.0 MPa). Bonds to the spherical amalgam were probably more reliable. The intermediate application of the 4-META resins AP and RMP generally created significantly stronger bonds to all three basic types of amalgam products than the bonds obtained with the All-Bond 2 primers. The effect of abrasive-particle size on bond strength to different amalgam surfaces was not usually significant (p > 0.05). The implications of these findings are discussed in relationship to clinical experience bonding orthodontic attachments to large amalgam restorations in posterior teeth.

Life of a Tooth: A Visual Timeline

MedlinePlus Videos and Cool Tools

... InfoBites Quick Reference Learn more Sports and Oral Health What is Dental Amalgam (Silver Filling)? Pacifiers Have ... Home | InfoBites | Find a Dentist | Your Family's Oral Health | RSS About AGD | Contact AGD | Site Map | Reprints ...

Allergic Reactions to Dental Materials-A Systematic Review

PubMed Central

Chopra, Radhika; Sachdev, Vinod

2015-01-01

Introduction Utility of various dental materials ranging from diagnosis to rehabilitation for the management of oral diseases are not devoid of posing a potential risk of inducing allergic reactions to the patient, technician and dentist. This review aims to develop a systematic approach for the selection and monitoring of dental materials available in the market thereby giving an insight to predict their risk of inducing allergic reactions. Materials and Methods Our data included 71 relevant articles which included 60 case reports, 8 prospective studies and 3 retrospective studies. The source of these articles was Pub Med search done with the following terms: allergies to impression materials, sodium hypochlorite, Ledermix paste, zinc oxide eugenol, formaldehyde, Latex gloves, Methyl methacrylate, fissure sealant, composites, mercury, Nickel-chromium, Titanium, polishing paste and local anaesthesia. All the relevant articles and their references were analysed. The clinical manifestations of allergy to different dental materials based on different case reports were reviewed. Results After reviewing the literature, we found that the dental material reported to cause most adverse reactions in patients is amalgam and the incidence of oral lichenoid reactions adjacent to amalgam restorations occur more often than other dental materials. Conclusion The most common allergic reactions in dental staff are allergies to latex, acrylates and formaldehyde. While polymethylmethacrylates and latex trigger delayed hypersensitivity reactions, sodium metabisulphite and nickel cause immediate reactions. Over the last few years, due to the rise in number of patients with allergies from different materials, the practicing dentists should have knowledge about documented allergies to known materials and thus avoid such allergic manifestations in the dental clinic. PMID:26557634

The FiCTION dental trial protocol - filling children's teeth: indicated or not?

PubMed

Innes, Nicola P T; Clarkson, Jan E; Speed, Chris; Douglas, Gail V A; Maguire, Anne

2013-06-01

There is a lack of evidence for effective management of dental caries (decay) in children's primary (baby) teeth and an apparent failure of conventional dental restorations (fillings) to prevent dental pain and infection for UK children in Primary Care. UK dental schools' teaching has been based on British Society of Paediatric Dentistry guidance which recommends that caries in primary teeth should be removed and a restoration placed. However, the evidence base for this is limited in volume and quality, and comes from studies conducted in either secondary care or specialist practices. Restorations provided in specialist environments can be effective but the generalisability of this evidence to Primary Care has been questioned. The FiCTION trial addresses the Health Technology Assessment (HTA) Programme’s commissioning brief and research question “What is the clinical and cost effectiveness of restoration caries in primary teeth, compared to no treatment?” It compares conventional restorations with an intermediate treatment strategy based on the biological (sealing-in) management of caries and with no restorations. This is a Primary Care-based multi-centre, three-arm, parallel group, patient-randomised controlled trial. Practitioners are recruiting 1461 children, (3-7 years) with at least one primary molar tooth where caries extends into dentine. Children are randomized and treated according to one of three treatment approaches; conventional caries management with best practice prevention, biological management of caries with best practice prevention or best practice prevention alone. Baseline measures and outcome data (at review/treatment during three year follow-up) are assessed through direct reporting, clinical examination including blinded radiograph assessment, and child/parent questionnaires. The primary outcome measure is the incidence of either pain or infection related to dental caries. Secondary outcomes are; incidence of caries in primary and

Atraumatic restorative treatment (ART): a three-year clinical study in Malawi--comparison of conventional amalgam and ART restorations.

PubMed

Kalf-Scholte, Sonja M; van Amerongen, Willem E; Smith, Albert J E; van Haastrecht, Harry J A

2003-01-01

This study compares the quality of class I restorations made with the atraumatic restorative treatment (ART) technique and conventional class I amalgam restorations. The study was carried out among secondary school students in Mzuzu, Malawi. First-year students in 1987 who needed at least two class I restorations were selected. Based on a split-mouth design, each participant received both ART and conventional restorations. The 89 pairs of class I cavities were divided randomly into two groups, since two different cermet ionomer cement (CIC) filling materials were used. Impressions of the restorations and subsequent models were made shortly after restoration, after six months, one year, two years, and three years. The quality of the restorations was determined on the models following the US Public Health Service criteria. Bulk fracture, contour, marginal integrity, and surface texture of the restorations were recorded and evaluated separately. Survival rates were determined by the resultant score of all criteria. Though conventional amalgam restorations performed better on all criteria, this difference was significant only for the contour criterion. The survival rates of ART restorations after three years (81.0%) were lower than those of amalgam restorations (90.4%) (P=.067). The quality of ART class I restorations is competitive with that of conventional amalgam restorations.

Integrated starting and running amalgam assembly for an electrodeless fluorescent lamp

DOEpatents

Borowiec, Joseph Christopher; Cocoma, John Paul; Roberts, Victor David

1998-01-01

An integrated starting and running amalgam assembly for an electrodeless SEF fluorescent lamp includes a wire mesh amalgam support constructed to jointly optimize positions of a starting amalgam and a running amalgam in the lamp, thereby optimizing mercury vapor pressure in the lamp during both starting and steady-state operation in order to rapidly achieve and maintain high light output. The wire mesh amalgam support is constructed to support the starting amalgam toward one end thereof and the running amalgam toward the other end thereof, and the wire mesh is rolled for friction-fitting within the exhaust tube of the lamp. The positions of the starting and running amalgams on the wire mesh are jointly optimized such that high light output is achieved quickly and maintained, while avoiding any significant reduction in light output between starting and running operation.

Single crowns versus conventional fillings for the restoration of root-filled teeth.

PubMed

Sequeira-Byron, Patrick; Fedorowicz, Zbys; Carter, Ben; Nasser, Mona; Alrowaili, Eman F

2015-09-25

Endodontic treatment involves removal of the dental pulp and its replacement by a root canal filling. Restoration of root filled teeth can be challenging due to structural differences between vital and non-vital root-filled teeth. Direct restoration involves placement of a restorative material e.g. amalgam or composite, directly into the tooth. Indirect restorations consist of cast metal or ceramic (porcelain) crowns. The choice of restoration depends on the amount of remaining tooth, and may influence durability and cost. The decision to use a post and core in addition to the crown is clinician driven. The comparative clinical performance of crowns or conventional fillings used to restore root-filled teeth is unknown. This review updates the original, which was published in 2012. To assess the effects of restoration of endodontically treated teeth (with or without post and core) by crowns versus conventional filling materials. We searched the following databases: the Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE via OVID, EMBASE via OVID, CINAHL via EBSCO, LILACS via BIREME. We also searched the reference lists of articles and ongoing trials registries.There were no restrictions regarding language or date of publication. The search is up-to-date as of 26 March 2015. Randomised controlled trials (RCTs) or quasi-randomised controlled trials in participants with permanent teeth that have undergone endodontic treatment. Single full coverage crowns compared with any type of filling materials for direct restoration or indirect partial restorations (e.g. inlays and onlays). Comparisons considered the type of post and core used (cast or prefabricated post), if any. Two review authors independently extracted data from the included trial and assessed its risk of bias. We carried out data analysis using the 'treatment as allocated' patient population, expressing estimates of intervention effect for dichotomous data as risk ratios, with 95% confidence

Silver-tin alloys and amalgams: electrochemical considerations.

PubMed

Mueller, H J

1980-01-01

The corrosion potential and anodic polarization profiles of a representative number of silver-tin alloys and their corresponding amalgams in a physiological solution were determined and compared to their microstructures. For the alloys with tin-content greater than 27%(wt) and for all amalgams, the corrosion process is related to the attack of free tin for the alloys and to the gamma-2 tin for the amalgams. The gamma-2 concentration in the amalgams increases with an increase in tin-content. For alloys with tin-content less than 27%, the corrosion process is even more restricted than for the process observed with pure silver. From a developed theory based upon the potential-time and polarization results, association of the O2 reduction process on a SnO cathodic film to an intermediate specie of H2O2 is made. The rate of H2O2 decomposition on a SnO surface in a four electron process is thought to control the O2 reduction overvoltage. The O2 reduction overvoltage decreases with increases in the silver-content of the amalgam, particularily seen with the 8 and 12% tin compositions. Due to the polarization induced corrosion process, a phase with high silver and high mercury concentrations was observed over the unreacted particles.

Synthesis and characterization of dental composites

NASA Astrophysics Data System (ADS)

Djustiana, Nina; Greviana, Nadia; Faza, Yanwar; Sunarso

2018-02-01

During the last few decades, the increasing demands in esthetic dentistry have led to the development of dental composites material that provide similar appearance to the natural teeth. Recently, esthetic trend was an issue which increase the demand for teeth restorations that is similar with the origin. The esthetics of dental composite are more superior compared to amalgam, since its color look similar with natural teeth. Various dental composites have been developed using many type of fillers such as amorphous silica, quartz), borosilicate, Li-Sr-Ba-Al glass and oxide: zirconia and alumina. Researchers in Faculty of Dentistry University of Padjadjaran have prepared dental composites using zirconia-alumina-silica (ZAS) system as the filler. The aim is to improve the mechanical properties and the esthetic of the dental composites. The ZAS was obtained from chemical grade purity chemicals and Indonesia's natural sand as precursors its characterization were also presented. This novel method covers the procedure to synthesis and characterize dental composites in Padjadjaran University and some review about dental composites in global research.

21 CFR 872.3275 - Dental cement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns or...

21 CFR 872.3275 - Dental cement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns or...

21 CFR 872.3275 - Dental cement.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns or...

21 CFR 872.3275 - Dental cement.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns or...

21 CFR 872.3275 - Dental cement.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns or...

48. INTERIOR VIEW FROM THE WEST END OF THE AMALGAMATION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

48. INTERIOR VIEW FROM THE WEST END OF THE AMALGAMATION TABLES LOOKING NORTH TOWARDS THE STAMP BATTERIES WITH AMALGAM TRAPS SHOWN IN THE BOTTOM FOREGROUND. NOTE THE EXTANT EQUIPMENT IN THE FOREGROUND THAT THE PARK USES TO INTERPRET THE MILL. FROM LEFT TO RIGHT, A SCREEN FROM THE MORTAR BOX, A STAMP STOP. A (HUMAN'S) SHOE, A DIE FROM THE BOTTOM OF A MORTAR BOX, AN AMALGAM SCRAPPER AND AN AMALGAM BUCKET. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

Problems associated with restorative materials--dentists' views in Finland and Sweden.

PubMed

Widström, E; Sundberg, H

1991-01-01

During the past 10-15 years the possible side-effects of dental restorative materials, especially due to amalgam fillings, have caused a lively debate in Sweden. There is an extensive literature on the chemical and biological properties of dental materials but no investigations have dealt with the providers' attitudes. The purpose of this study was to find out the dentists' experiences of and attitudes to patients who state they have problems related to dental restorative materials and compare the dentists' subjective assessments of those side-effects in two neighboring countries, Finland and Sweden. Information was collected by postal questionnaires addressed to dentists chosen at random in Finland (n = 625) and in Sweden (n = 960). The response rate was 73 per cent and 72 per cent respectively. The results showed that 99 per cent of the respondents had patients questioning the safety of dental materials. The number of such patients was estimated to be three times higher in Sweden (124 patients per dentist in 1989) than in Finland (39 patients per dentist). More than 90 per cent of the questions from the patients regarded amalgam fillings. Statistically significant differences were found between the respondents' opinions of amalgam, 81 per cent of the Finnish contrary to 59 per cent of the Swedish respondents considered the risk of side-effects to be low when using this material. About 90 per cent of the respondents considered glass-ionomer, gold and ceramic restorations safe, but only half of them were convinced of the safety of composite. A great majority of the Swedish respondents (79 per cent) claimed that the patients should get their fillings changed without odontologic indications if they insisted on it and paid for the treatment in comparison to 22 per cent of the Finnish respondents (p less than 0.001). In case dental insurance was to pay for this kind of treatment it was accepted by 6 per cent of the Finns and 25 per cent of the Swedes. The attitude to

Radiochemical separation of gallium by amalgam exchange

USGS Publications Warehouse

Ruch, R.R.

1969-01-01

An amalgam-exchange separation of radioactive gallium from a number of interfering radioisotopes has been developed. A dilute (ca. 0.3%) gallium amalgam is agitated with a slightly acidic solution of 72Ga3+ containing concentrations of sodium thiocyanate and either perchlorate or chloride. The amalgam is then removed and the radioactive gallium stripped by agitation with dilute nitric acid. The combined exchange yield of the perchlorate-thiocyanate system is 90??4% and that of the chloride-thiocyanate system is 75??4%. Decontamination yields of most of the 11 interfering isotopes studied were less than 0.02%. The technique is applicable for use with activation analysis for the determination of trace amounts of gallium. ?? 1969.

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT REMOVAL OF MERCURY FROM DENTAL OFFICE WASTEWATER

EPA Science Inventory

Verification testing of the DRNA Mercury Recovery Unit (MRU) was conducted during a seven-week period, at a dental office in Michigan that had three operatory rooms and two hygiene rooms. The office operated four days per week and averaged approximately eight (8) mercury amalgam ...

Assessment of exposures and potential risks to the US adult population from wear (attrition and abrasion) of gold and ceramic dental restorations.

PubMed

Richardson, G Mark; Clemow, Scott R; Peters, Rachel E; James, Kyle J; Siciliano, Steven D

2016-01-01

Little has been published on the chemical exposures and risks of dental restorative materials other than from dental amalgam and composite resins. Here we provide the first exposure and risk assessment for gold (Au) alloy and ceramic restorative materials. Based on the 2001-2004 US National Health and Nutrition Examination Survey (NHANES), we assessed the exposure of US adults to the components of Au alloy and ceramic dental restorations owing to dental material wear. Silver (Ag) is the most problematic component of Au alloy restorations, owing to a combination of toxicity and proportional composition. It was estimated that adults could possess an average of four tooth surfaces restored with Au alloy before exceeding, on average, the reference exposure level (REL) for Ag. Lithium (Li) is the most problematic component of dental ceramics. It was estimated that adults could possess an average of 15 tooth surfaces restored with ceramics before exceeding the REL for Li. Relative risks of chemical exposures from dental materials decrease in the following order: Amalgam>Au alloys>ceramics>composite resins.

Dental Office Waste – Public Health and Ecological Risk

PubMed Central

Muhamedagic, Belma; Muhamedagic, Lejla; Masic, Izet

2009-01-01

CONFLICT OF INTEREST: NONE DECLARED Waste management is one of the key ecological challenges of the modern world. As dental practitioners, we must recognize that some of the materials and procedures we use to provide dental health services may present challenges to the environment. Realizing this, we can begin to take measures to minimize the production of these wastes and their potential environmental effects. Dental office waste typically cause toxic chemicals to enter our streams, sewers, and landfills. This paper identifies some common wastes produced by dental offices (dental amalgam, silver, lead, biomedical and general office waste) and provides practical suggestions for reducing the impact of our profession on the environment. To dispose of dental wastes, if recycling is not an option, proper disposal as hazardous waste is necessary. But, problem is that dental waste is in most cases dumped at uncontrolled disposal sites, and that is public health and ecological risk. PMID:24133379

Jordanian dentists' knowledge and implementation of eco-friendly dental office strategies.

PubMed

Al Shatrat, Sabha M; Shuman, Deanne; Darby, Michele L; Jeng, Hueiwang A

2013-06-01

To investigate the implementation of eco-friendly dental office strategies by Jordanian dentists. Self-designed questionnaires were provided to 150 dentists working in private dental practices in the city of Amman, the capital of Jordan. Dentists' names and addresses were obtained from the Jordanian Dental Association. Overall, the level of knowledge about eco-friendly dental offices strategies was high for amalgam, radiology, paper waste, infection control and energy and water conservation. In terms of implementation, the majority of Jordanian dentists apply few eco-friendly dental offices strategies. The most frequently identified barriers to implementation of eco-friendly dental offices strategies were cost and lack of incentives from the government. Most Jordanian dental practices are not eco-friendly. A continued focus on the impact of dental practices on the environment is needed through formal and continuing dental education. Results of this study can guide policy development to encourage implementation of eco-friendly strategies. © 2013 FDI World Dental Federation.

Synchrotron-radiation-based X-ray micro-computed tomography reveals dental bur debris under dental composite restorations.

PubMed

Hedayat, Assem; Nagy, Nicole; Packota, Garnet; Monteith, Judy; Allen, Darcy; Wysokinski, Tomasz; Zhu, Ning

2016-05-01

Dental burs are used extensively in dentistry to mechanically prepare tooth structures for restorations (fillings), yet little has been reported on the bur debris left behind in the teeth, and whether it poses potential health risks to patients. Here it is aimed to image dental bur debris under dental fillings, and allude to the potential health hazards that can be caused by this debris when left in direct contact with the biological surroundings, specifically when the debris is made of a non-biocompatible material. Non-destructive micro-computed tomography using the BioMedical Imaging & Therapy facility 05ID-2 beamline at the Canadian Light Source was pursued at 50 keV and at a pixel size of 4 µm to image dental bur fragments under a composite resin dental filling. The bur's cutting edges that produced the fragment were also chemically analyzed. The technique revealed dental bur fragments of different sizes in different locations on the floor of the prepared surface of the teeth and under the filling, which places them in direct contact with the dentinal tubules and the dentinal fluid circulating within them. Dispersive X-ray spectroscopy elemental analysis of the dental bur edges revealed that the fragments are made of tungsten carbide-cobalt, which is bio-incompatible.

Surface modification for bonding between amalgam and orthodontic brackets.

PubMed

Wongsamut, Wittawat; Satrawaha, Sirichom; Wayakanon, Kornchanok

2017-01-01

Testing of methods to enhance the shear bond strength (SBS) between orthodontic metal brackets and amalgam by sandblasting and different primers. Three hundred samples of amalgam restorations (KerrAlloy ® ) were prepared in self-cured acrylic blocks, polished, and divided into two groups: nonsandblasted and sandblasted. Each group was divided into five subgroups with different primers used in surface treatment methods, with a control group of bonded brackets on human mandibular incisors. Following the surface treatments, mandibular incisor brackets (Unitek ® ) were bonded on the amalgam with adhesive resin (Transbond XT ® ). The SBS of the samples was tested. The adhesive remnant index (ARI) and failure modes were then determined under a stereo-microscope. Two-way analysis of variance, Chi-square, and Kruskal-Wallis tests were performed to calculate the correlations between and among the SBS and ARI values, the failure modes, and surface roughness results. There were statistically significant differences of SBS among the different adhesive primers and sandblasting methods ( P < 0.05). The sandblasted amalgam with Assure Plus ® showed the highest SBS ( P < 0.001). Samples mainly showed an ARI score = 1 and mix-mode failure. There was a statistically significant difference of surface roughness between nonsandblasted amalgam and sandblasted amalgam ( P < 0.05), but no significant differences among priming agents ( P > 0.05). Using adhesive primers with sandblasting together effectively enhances the SBS between orthodontic metal brackets and amalgam. The two primers with the ingredient methacryloxydecyl dihydrogen phosphate (MDP) monomer, Alloy Primer ® and Assure Plus ® , were the most effective. Including sandblasting in the treatment is essential to achieve the bonding strength required.

An evaluation of a lathe-cut high-copper amalgam alloy.

PubMed

Knibbs, P J; Plant, C G; Shovelton, D S; Jones, P A

1987-09-01

Modification of an amalgam alloy may give rise to improved physical properties. The physical properties of a newly formulated, single-composition lathe-cut amalgam alloy were studied and found to be superior to those of a conventional lathe-cut amalgam alloy. However, such modification in formulation may result in changes in the clinical handling properties of the material. The high-copper amalgam alloy was assessed by a panel of general practitioners who found that the general handling properties of the material were similar to those of conventional lathe-cut amalgam alloys. The longer term performance of the high-copper alloy was assessed by means of a blind, controlled clinical trial carried out by two operators. A 1-year assessment of the resulting restorations and tooth replicas could not distinguish between the high-copper alloy and a conventional alloy. The two alloys had both given good clinical results.

Thirty-five year review of a mercury monitoring service for Scottish dental practices.

PubMed

Duncan, A; O'Reilly, D Stj; McDonald, E B; Watkins, T R; Taylor, M

2011-02-12

To review a long-standing mercury monitoring service offered to staff in dental practices in Scotland. During the first 20 years of the service, dentists and their staff were contacted by letter and invited to participate. Respondents were asked to collect samples of head hair, pubic hair, fingernail and toenail for analysis of mercury. After 1995, head hair samples were collected initially and further samples were only measured if head hair mercury was elevated. At the start of this scheme many staff, including administrative staff, had systemic exposure to mercury (defined as increased mercury in all four samples). Incidents of exposure have decreased over the 35 years and are now very rare. Male staff were found to have higher mercury concentrations than female staff and dentists tended to have higher concentrations than other staff. Staff working in dental practices more than five years old had small but discernable increases in head hair mercury concentration. In recent years the use of reusable capsules such as Dentomats has been associated with a slight but statistically significant increase in head hair mercury concentrations when compared to the use of encapsulated amalgam systems. Staff wearing open-toed footwear had significantly higher toenail mercury concentrations compared to those who wore shoes. Exposure of staff to mercury in Scottish dental practices is currently now very low. This is probably as a result of increased awareness to the toxicity of mercury and improved methods of preparing amalgam. It may be possible to reduce exposure further, although probably only slightly, by upgrading practices and using encapsulated mercury amalgam.

Reasons for Placement of Restorations on Previously Unrestored Tooth Surfaces by Dental PBRN Dentists

PubMed Central

Nascimento, Marcelle M.; Gordan, Valeria V.; Qvist, Vibeke; Litaker, Mark S.; Rindal, D. Brad; Williams, O.D.; Fellows, Jeffrey L.; Ritchie, Lloyd K.; Mjör, Ivar A.; McClelland, Jocelyn; Gilbert, Gregg H.

2010-01-01

Objective To identify and quantify the reasons for placing restorations on unrestored permanent tooth surfaces and the dental materials used by Dental Practice-Based Research Network (DPBRN; www.DentalPBRN.org) dentists. Methods A total of 229 DPBRN practitioner-investigators collected data on 9,890 consecutive restorations from 5,810 patients. Information included: (1) reasons for restoring; (2) tooth and surfaces restored; and (3) restorative materials employed. Results Primary caries (85%) and non-carious defects (15%), which included abrasion/ abfraction/ erosion lesions and tooth fracture, were the main reasons for placement of restorations. Restorations due to caries were frequently placed on occlusal surfaces (49%), followed by distal, mesial, buccal/facial, lingual/palatal, and incisal surfaces. Amalgam was used for 46% of the molar and 45% of the premolar restorations. Directly placed resin-based composite (RBC) was used for 48% of the molar, 49% of the premolar, and 92% of the anterior restorations. Conclusion Dental caries on occlusal and proximal surfaces of molar teeth are the main reasons for placing restorations on previously unrestored tooth surfaces by DPBRN practitioner-investigators. RBC is the material most commonly used for occlusal and anterior restorations. Amalgam remains the material of choice to restore proximal caries in posterior teeth, although there are significant differences by DPBRN region. PMID:20354094

Three-body wear of a hand-consolidated silver alternative to amalgam.

PubMed

Xu, H H; Eichmiller, F C; Giuseppetti, A A; Ives, L K; Parry, E E; Schumacher, G E

1999-09-01

Recent studies have investigated a mercury-free silver alternative to amalgam, but the silver powders required a relatively high compaction pressure to consolidate. The aim of the present study was to consolidate a precipitated silver powder into a cohesive solid using an air-driven pneumatic condenser fitted with an amalgam plugger at a clinically realistic load, and to study the mechanisms and rates of three-body wear of the consolidated silver in comparison with that of an amalgam. The silver powder was annealed, rinsed with a dilute acid, and consolidated either in a prepared tooth cavity or in a specimen mold at a load of 15 N. A four-station wear machine was used where each specimen was immersed in a slurry containing polymethyl methacrylate beads, then a steel pin was loaded and rotated against the specimen at a maximum load of 76 N. The flexural strength in MPa (mean +/- SD; n = 10) was 86 +/- 20 for amalgam, 181 +/- 45 for silver with a polished surface, and 202 +/- 21 for silver with a burnished surface. After 4 x 10(5) wear cycles, the wear scar depth in microm was 134 +/- 54 for amalgam, 143 +/- 8 for polished silver, and 131 +/- 9 for burnished silver, which were not significantly different (Tukey's multiple comparison test; family confidence coefficient = 0.95). SEM examination revealed cracks and fracture pits in the worn surface of amalgam, in contrast to a smooth surface in silver. Wear and material removal in amalgam occurred by microfracture and dislodgement of cracked segments, while wear in the silver occurred by ductile deformation and flow of materials. To conclude, the consolidated silver possesses a three-body wear resistance similar to that of amalgam, and a higher resistance to wear-induced damage and cracking than amalgam. The mechanism of wear in amalgam is microfracture and material dislodgement, while that in consolidated silver is ductile deformation and flow of material.

[Mercury impregnation in dentists and dental assistants in Monastir city, Tunisia].

PubMed

Chaari, N; Kerkeni, A; Saadeddine, S; Neffati, F; Khalfallah, T; Akrout, M

2009-06-01

The property of mercury to amalgamate with other metals is used to create a material for filling teeth. This material remains the cheapest and most efficient in tooth restoration. Mercurial toxicity has been documented since Antiquity but the metal remains widely used in some countries. This study compared mercury impregnation in dentists and dental assistants in Monastir (Tunisia) to another population not exposed professionally. A cross-sectional study was made on 52 dentists and dental assistants working in private offices and in the stomatology unit of the Monastir teaching hospital, with a control group of 52 physicians and nurses working in the Monastir Fattouma Bourguiba hospital. The groups were paired according to age and gender. The study lasted three months. A questionnaire investigated the socioprofessional features of the study population, non professional mercury exposure, work environment, the various amalgam handling and preparation techniques, and preventive hygiene measures. Urinary and salivary sampling was performed so as to prevent any accidental mercurial contamination. Mercury level was assessed by atomic absorption spectroscopy in an automatic sampler, urine creatinine with Jaffé's colorimetric reaction. The results of mercury level assessment were expressed in microg/g of creatinine, salivary mercury in mug/l. The statistical analysis was made with the Epi.info 6 software. Khi(2) and Fisher tests were used to compare qualitative variables. The ANOVA test was used to compare averages with a statistic significance threshold at 0.05. Sixty-one percent of individuals with risk exposure worked in a dental clinic. Bruxism and onychophagia were more important in the control group with a significant statistical difference (respectively, p=0.01 and p<0.0001). The urinary and salivary mercury levels were significantly increased in the exposed group, with respective values of 20.4+/-42.4microg/g of creatinine and 10.6+/-13.02microg/l versus 0

Evaluation of marginal adaptation of root-end filling materials using scanning electron microscopy.

PubMed

Oliveira, Helder Fernandes; Gonçalves Alencar, Ana Helena; Poli Figueiredo, José Antônio; Guedes, Orlando Aguirre; de Almeida Decurcio, Daniel; Estrela, Carlos

2013-01-01

The importance of perfect apical seal in endodontics, more specifically in periradicular surgery, is the motivation/reason for development of root-end filling materials with favorable physical, chemical and biological characteristics. The aim of this in vitro study was to evaluate the marginal adaptation of root-end filling materials using scanning electron microscopy. Twenty five human maxillary anterior teeth were prepared using a K-File #50 to 1 mm short of the apical foramen and filled with gutta-percha and Sealapex using the lateral compaction technique. The apical 3 mm of the roots were sectioned perpendicularly to the long axis of the teeth. A 3-mm-deep root-end cavity was prepared using ultrasonic tips powered by an Enac ultrasonic unit. The teeth were randomly assigned to five groups according to the materials tested including IRM, amalgam, ProRoot MTA, Super-EBA and Epiphany/Resilon. Root-end cavities were filled with the materials prepared according to the manufacturers' instructions. The root apices were carefully prepared for sputter coating and later evaluation using Scanning Electron Microscope (SEM). The images of root-end fillings were divided into four quadrants and distributed into five categories according to the level of marginal adaptation between the root-end material and the root canal walls. The Fisher exact test with Bonferroni correction was used for statistical analysis. The level of significance was set at P = 0.005. SEM images showed the presence of gaps in the root-end filling materials. No significant difference was observed between the tested materials (P > 0.005). ProRoot MTA, IRM, amalgam, Super-EBA and Epiphany/Resilon showed similar marginal adaptation as root-end filling materials.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arenholt-Bindslev, D.

Increasing knowledge about the risk of toxic effects caused by anthropogenic mercury accumulation in ecosystems has resulted in a growing pressure for reduction of the discharge of mercury waste. Consequently, the mercury waste problems of dental clinics have been given increased attention, and restrictions on handling and discharge of contaminated waste have been established in several countries. Major amalgam particles from trituration surplus of those produced during the carving and burnishing of new amalgam restorations are generally collected in coarse filters and sold for refinement. Minor amalgam particles released by production of new fillings or by removal of old restorationsmore » partly sediment in tubes and drains. The remaining particles are carried with the waste water stream to the local purifying plant. In Scandinavia, the industrial discharge of mercury-contaminated waste water has been reduced to a minimum. According to recent investigations, dental clinics appear to be responsible for the major amount of mercury collected in the sludge generated in purifying plants. If threshold values for heavy metal content, including mercury, are exceeded, the sludge is not allowed to be recycled as fertilizer. Installation of an approved amalgam-separating apparatus in dental clinics is now mandatory in several countries--for example, Switzerland, Germany, Sweden, and Denmark. Approval of amalgam separators is based on national testing programs, including clinical or laboratory tests demanding 95-99% separating efficiency. 18 refs.« less

Does dental caries affect dental development in children and adolescents?

PubMed Central

Dhamo, Brunilda; Elezi, Besiana; Kragt, Lea; Wolvius, Eppo B; Ongkosuwito, Edwin M

2018-01-01

Although a link between dietary changes, caries, and dental development has been observed, the literature provides little insight about this relationship. The aim of our study was to investigate the association between dental caries and dental development in a clinical sample of Albanian children and adolescents. In total, 118 children and adolescents, born between 1995 and 2004 and aged 6–15 years, were included. Dental caries in the deciduous dentition was assessed using the Decayed, Filled Teeth (dft) index and dental caries in the permanent dentition was assessed using the Decayed, Missing, Filled Teeth (DMFT) index. Dental development during the permanent dentition was determined using the Demirjian method. Linear and ordinal regression models were applied to analyze the associations of dental caries with dental age and developmental stages of each left mandibular tooth. Dental caries in the deciduous dentition, estimated as a median dft of 2.0 (90% range, 0.0–9.1), was significantly associated with lower dental age (β = -0.21; 90% CI: -0.29, -0.12) and with delayed development of the canine, both premolars, and the second molar. Untreated dental caries (dt) was associated with lower dental age (β = -0.19; 90% CI: -0.28, -0.10). Dental caries in the permanent dentition, estimated as a median DMFT of 1.0 (90% range, 0.0–8.0), was not significantly associated with dental age (β = 0.05; 90% CI: -0.04, 0.14). However, the DMFT was associated with the advanced stages of development of both premolars and the second molar. The untreated dental caries in the deciduous dentition delays the development of permanent teeth. PMID:29659350

Reduction of metal artifact in three-dimensional computed tomography (3D CT) with dental impression materials.

PubMed

Park, W S; Kim, K D; Shin, H K; Lee, S H

2007-01-01

Metal Artifact still remains one of the main drawbacks in craniofacial Three-Dimensional Computed Tomography (3D CT). In this study, we tried to test the efficacy of additional silicone dental impression materials as a "tooth shield" for the reduction of metal artifact caused by metal restorations and orthodontic appliances. 6 phantoms with 4 teeth were prepared for this in vitro study. Orthodontic bracket, bands and amalgam restorations were placed in each tooth to reproduce various intraoral conditions. Standardized silicone shields were fabricated and placed around the teeth. CT image acquisition was performed with and without silicone shields. Maximum value, mean, and standard deviation of Hounsfield Units (HU) were compared with the presence of silicone shields. In every situation, metal artifacts were reduced in quality and quantity when silicone shields are used. Amalgam restoration made most serious metal artifact. Silicone shields made by dental impression material might be effective way to reduce the metal artifact caused by dental restoration and orthodontic appliances. This will help more excellent 3D image from 3D CT in craniofacial area.

The integrity of bonded amalgam restorations: a clinical evaluation after five years.

PubMed

Mach, Zbynek; Regent, Jan; Staninec, Michal; Mrklas, Lubor; Setcos, James C

2002-04-01

Bonded amalgam restorations have been studied extensively in vitro, but few long term clinical studies exist. The authors examined the clinical performance of bonded amalgam restorations after five years of clinical service an compared it with that of nonbonded amalgam restorations. The authors placed 75 bonded and 62 nonbonded amalgam restorations in patients needing restorations. Most of the restorations were placed in conventional preparations; six bonded restorations were placed in nonretentive cavities. They were evaluated after a five-year period of clinical service by two trained dentists using a mirror and explorer and following modified U.S. Public Health Service criteria. Statistical analysis (via Fisher exact test) showed no significant differences between the two techniques when conventional preparations were used. Restorations in nonretentive preparations were successful during this period. Bonded and nonbonded amalgam restorations yielded similar results in conventional preparations after five years of clinical service. Bonded amalgam restorations were clinically successful in a limited number of nonretentive preparations over a five-year period. Bonded amalgam restorations can be used successfully in conventional preparations and possibly in nonretentive preparations as well, and can be expected to last at least five years.

The FiCTION dental trial protocol – filling children’s teeth: indicated or not?

PubMed Central

2013-01-01

Background There is a lack of evidence for effective management of dental caries (decay) in children’s primary (baby) teeth and an apparent failure of conventional dental restorations (fillings) to prevent dental pain and infection for UK children in Primary Care. UK dental schools’ teaching has been based on British Society of Paediatric Dentistry guidance which recommends that caries in primary teeth should be removed and a restoration placed. However, the evidence base for this is limited in volume and quality, and comes from studies conducted in either secondary care or specialist practices. Restorations provided in specialist environments can be effective but the generalisability of this evidence to Primary Care has been questioned. The FiCTION trial addresses the Health Technology Assessment (HTA) Programme’s commissioning brief and research question “What is the clinical and cost effectiveness of restoration caries in primary teeth, compared to no treatment?” It compares conventional restorations with an intermediate treatment strategy based on the biological (sealing-in) management of caries and with no restorations. Methods/Design This is a Primary Care-based multi-centre, three-arm, parallel group, patient-randomised controlled trial. Practitioners are recruiting 1461 children, (3–7 years) with at least one primary molar tooth where caries extends into dentine. Children are randomized and treated according to one of three treatment approaches; conventional caries management with best practice prevention, biological management of caries with best practice prevention or best practice prevention alone. Baseline measures and outcome data (at review/treatment during three year follow-up) are assessed through direct reporting, clinical examination including blinded radiograph assessment, and child/parent questionnaires. The primary outcome measure is the incidence of either pain or infection related to dental caries. Secondary outcomes are

Discrimination of tooth layers and dental restorative materials using cutting sounds.

PubMed

Zakeri, Vahid; Arzanpour, Siamak; Chehroudi, Babak

2015-03-01

Dental restoration begins with removing carries and affected tissues with air-turbine rotary cutting handpieces, and later restoring the lost tissues with appropriate restorative materials to retain the functionality. Most restoration materials eventually fail as they age and need to be replaced. One of the difficulties in replacing failing restorations is discerning the boundary of restorative materials, which causes inadvertent removal of healthy tooth layers. Developing an objective and sensor-based method is a promising approach to monitor dental restorative operations and to prevent excessive tooth losses. This paper has analyzed cutting sounds of an air-turbine handpiece to discriminate between tooth layers and two commonly used restorative materials, amalgam and composite. Support vector machines were employed for classification, and the averaged short-time Fourier transform coefficients were selected as the features. The classifier performance was evaluated from different aspects such as the number of features, feature scaling methods, classification schemes, and utilized kernels. The total classification accuracies were 89% and 92% for cases included composite and amalgam materials, respectively. The obtained results indicated the feasibility and effectiveness of the proposed method.

Teaching of direct posterior resin composite restorations in UK dental therapy training programmes.

PubMed

Lynch, C D; Wilson, N H F

2010-05-08

With the numbers of dental therapists involved in the delivery of dental care within the UK on the increase, and the trend towards the use of direct resin composites (composites) for the restoration of posterior teeth, this study was undertaken to describe the teaching of posterior composites in dental therapy training programmes in the UK. A secondary aim was to identify differences in techniques for posterior composites taught within these dental therapy training programmes. In 2008/9, a questionnaire seeking information on the teaching of posterior composites was distributed by email to 13 centres with dental therapy training programmes in the UK. This questionnaire sought information relating to the teaching of direct posterior composites to dental therapy students, including the amounts of preclinical and clinical teaching in respect of deciduous and permanent teeth, numbers of restorations placed, contraindications to placement, and details in respect of operative techniques. Ten completed responses were received (response rate = 77%). In ten programmes, student dental therapists received clinical training in the placement of composite restorations in the occlusal surfaces of premolar and permanent molar teeth, and nine programmes included such training for two and three surface occlusoproximal restorations. The mean proportions of posterior restorations placed clinically by the trainee dental therapists in permanent teeth using dental amalgam and composite were 52% and 46% respectively (range: amalgam = 20-95%; composite = 5-70%). With the exception of one programme, the teaching of posterior composites is a well established element of dental therapy training. Some variations were noted in the teaching of clinical techniques between respondent training centres. It is suggested that to ensure harmony in approaches to treatments provided by graduated therapists that training centres look to relevant consensus documents, such as those of the British Association

[Comparative study of the fracture resistance of sound upper premolars and upper premolars restored with bonded amalgam].

PubMed

Minto, André Marcelo Peruchi; Dinelli, Welingtom; Nonaka, Tomio; Thome, Luis Henrique de Camargo

2002-01-01

The purpose of this in vitro study was to determine the fracture resistance of upper premolars which had received class II preparations (conservative and extensive) and were restored with bonded amalgam, with two different adhesive systems. Seventy teeth were divided in four groups: group 1 (control), with ten sound teeth; group 2, with twenty prepared teeth (10 teeth received conservative cavities and 10, extensive cavities) restored with amalgam without any kind of liner; groups 3 and 4, similar to group 2, though with linings of glass ionomer cement (Vitrebond - 3M) (group 3) and dental adhesive (Scotchbond Multi-Purpose Plus - 3M) (group 4). The teeth were previously fixed in PVC cylinders with acrylic resin. After being restored and thermocycled, the test specimens were submitted to fracture by means of compression in an EMIC-MEM 2000 universal testing machine. After the application of the analysis of variance and complementary Tukey's test, we concluded that the utilized adhesive systems produced an increase of the fracture resistance of teeth presenting with conventional cavities; the teeth presenting with conservative cavities were more resistant in all experimental situations.

A Comparison of US and Japanese Dental Restorative Care Present on Service Members Recovered from the WWII Era.

PubMed

Shiroma, Calvin Y

2017-11-01

The documentation of dental materials used in the USA during the WWII era is readily available, while references for the Japanese are minimal. It was therefore important to build a photographic database of Japanese restorative care which could be utilized as a comparison tool for the deployed odontologist. The dental restorative care of approximately 400 US and 100 Japanese sets of remains was evaluated. Both countries share many similar restorative techniques to include collared crowns, full-coverage restorations, cantilever bridge/pontics to close spaces; restorative materials such as amalgam, gold, and zinc phosphate (temporary) restorations; and removable prostheses. The dental restorative materials most commonly used by US dentists include the amalgam and silicate cement, while the full-coverage crown was the type of restoration most frequently seen on the Japanese remains. Silicates, porcelain and replaceable crowns, and partial-coverage prepared crowns were not observed on the recovered Japanese remains. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

New inorganic/organic copolymers (ORMOCER{reg_sign}s) for dental applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolter, H.; Storch, W.; Ott, H.

1994-12-31

Urethane and thioether (meth)acrylate alkoxysilanes have been used, as sol-gel precursors, for the preparation of a special family of inorganic/organic copolymers (ORMOCER{reg_sign}s). The basic silane type offers the following structural and synthetic possibilities for modifying the properties of the resulting copolymers: variation of the number of alkoxy groups, combination with other, different, sol-gel precursors, variation of the number of attached (meth)acrylate groups (1--5), and variation within the molecular segment (kind, structure and length) connecting the inorganic with the organic polymer structure. To achieve the additional organic polymer structure in the cured copolymer the use of different radically induced polymerization approachesmore » (UV-, visible light-, thermal- and redox induced) is possible. Taking the incorporation of fillers into account, the Young`s modulus of these copolymers is adjustable in a range of 1--17,000 MPa, and the thermal expansion coefficient in a range of 17--250{center_dot}10{sup {minus}6}{center_dot}K{sup {minus}1} (5--50 C). Other advantages are the low shrinkage (1--2,8 vol.-%), the high flexural strength (up to 160 MPa), and the high abrasion resistance. This new copolymer type seems to have significant potential for medical applications, especially as dental filling material to replace the currently used controversial amalgam fillings.« less

Competence profiles in undergraduate dental education: a comparison between theory and reality.

PubMed

Koole, Sebastiaan; Van Den Brulle, Shani; Christiaens, Véronique; Jacquet, Wolfgang; Cosyn, Jan; De Bruyn, Hugo

2017-07-11

Competence profiles are purposed to provide a blueprint in support to develop and/or benchmark the learning outcomes of undergraduate dental curricula. This study aims to investigate whether a competence profile as proposed by academic- and clinical experts is able to represent the real clinical reality. A questionnaire was developed including questions about gender and age, perception about required competences, and educational organisation and was distributed among Flemish dentists via email and on paper during a symposium. The data was analysed using descriptive statistics, Chi-square and non-parametric Mann-Whitney U-tests. A total of 312 questionnaires were completed (=6.5% of dentist population, with similar gender and age characteristics). All competences in the European competence profile were rated between 7.2 and 9.4 on a 10-point scale. In dentists under 50 years, females rated the importance of identifying/managing anxiety and abnormal patient behaviour; and promoting/improving oral health as significantly higher than males. In dentists of 50 years and above, females rated 8 competences significantly higher than males, including obtaining/recording a complete history; identifying/managing anxiety and abnormal patient behaviour; obtaining/interpreting radiography; identifying temporomandibular and associated disorders; identifying orthodontic needs; awareness of own limitations/when to refer; managing dental urgencies; and basic-life-support/defibrillation. Clinical practice management was most frequently reported as additional competence to address in dental education. Furthermore, the respondents suggested an undergraduate dental curriculum based on 34% theoretical education, 26% preclinical skills training, and 40% clinical education and 86% agreed with a duration of 5 years. Finally, the respondents also illustrated the dynamic nature of dentistry including a reduction of amalgam fillings, a shift from individual practice to group practices, an

Magnitude of dental caries, missing and filled teeth in Malawi: National Oral Health Survey.

PubMed

Msyamboza, Kelias Phiri; Phale, Enock; Namalika, Jessie Mlotha; Mwase, Younam; Samonte, Gian Carlo; Kajirime, Doubt; Sumani, Sewedi; Chalila, Pax D; Potani, Rennie; Mwale, George Chithope-; Kathyola, Damson; Mukiwa, Weston

2016-03-09

Oral health problems are significant cause of morbidity particularly in sub-Saharan Africa. In Malawi, routine health management information system data over the years showed that oral health problems were one of the top ten reasons for outpatient attendance. However, to date, no national oral survey has been carried out to determine the prevalence of oral health problems. A national population-based cross-sectional survey was conducted in 2013. A total of 130 enumeration areas (EAs) were randomly selected and from each EA, 40 participants were randomly selected as per WHO STEPS survey protocol. Eligible participants were 12, 15, 35-44 and 65-74 year old. A multi-stage sampling design was used to obtain a national representative sample of these age groups. Oral examination was based on WHO diagnostic criteria (2010). A total of 5400 participants were enrolled in the survey. Of these: 3304 (61.3 %) were females, 2090 (38.7 %) were males; 327 (6.9 %) were from urban and 4386 (93.1 %) from rural areas; 1115 (20.6 %), 993 (17.3 %), 2306 (42.7 %) and 683 (12.6 %) were aged 12, 15, 35-44, 65-74 years respectively. Among 12 year-old, 15 year-old, 35-44 and 65-74 year age groups, prevalence of dental caries was 19.1, 21.9, 49.0 and 49.2 % respectively, overall 37.4 %. Prevalence of missing teeth was 2.7, 5.2, 47.7 and 79.9 %, overall 35.2 %. Prevalence of filled teeth was 0.2 %, 1.3 %, 8.7 %, 12.7 %, overall 6.5 %. Prevalence of bleeding gums was 13.0, 11.8, 30.8 and 36.1 %, overall 23.5 %. Toothache, dental caries and missing teeth were more common in females than males; 46.5 % vs 37.9 %, 40.5 % vs 32.4 %, 37.7 % vs 30.1 % respectively, all p < 0.05. Prevalence of dental caries and missing teeth in urban areas were as high as in the rural areas; 33.3 % vs 37.4 % and 30.9 % vs 33.7 % respectively, all p > 0.05. The mean number of decayed, missing and filled teeth (DMFT) in 12, 15, 35-44, 65-74 year old was 0.67, 0.71, 3.11 and 6.87 respectively. Self- reported brushing of

Amalgam bonding: visualization and clinical implications of adhesive displacement during amalgam condensation.

PubMed

Tyler, D W; Thurmeier, J

2001-01-01

Resin adhesive was visualized in this in vitro study of amalgam bonding using methylene blue dye incorporated into the resin or by scanning electron microscopy. Class II amalgam cavities were prepared in extracted teeth previously stored in buffered formalin. The preparations were then restored following manufacturers' instructions, but included methylene blue dissolved in ethanol into the adhesive resin mixture. This procedure had little effect on the setting time of the resin. Following condensation and carving, excess resin was incorporated into the body of the restorations as well as onto all adjacent coronal surfaces with significant occlusal and proximal accumulations. Resin also accumulated in significant amounts on the gingival floor of the proximal box and at line angles and retentive grooves within the preparation. In conclusion, radiological studies demonstrated that artifacts produced by resin accumulation at the gingival floor of the box could be mistaken for an open margin or recurrent caries. Other potential clinical consequences of resin residue on tooth surfaces are discussed, including the problem of interproximal ledges and occlusal discrepancies. The incorporation of a radiopaque material in the resin systems should be a universal requirement.

Microleakage of bonded amalgam restorations using different adhesive agents with dye under vacuum: an in vitro study.

PubMed

Parolia, Abhishek; Kundabala, M; Gupta, Vaibhav; Verma, Mudita; Batra, Chandni; Shenoy, Ramya; Srikant, N

2011-01-01

In an effort to minimize tooth preparation, yet provide additional retention to compromised tooth structure, bonded amalgam restorations were introduced. Various resin-based adhesives have been tried earlier under bonded amalgam restorations. Still there are controversies regarding the outcome of bonded amalgam restorations regarding their adaptability to the tooth structure and microleakage. Therefore, this study was undertaken to compare the microleakage of bonded amalgam restorations using different adhesive materials. Standard Class I cavities were prepared on occlusal surfaces of 60 human molars. Teeth (n=60) were divided into three groups according to the material employed, as follows: group I: amalgam with glass ionomer cement (GIC) (type I); group II: amalgam with resin cement (Panavia F 2.0) and group III: amalgam with Copalex varnish as a control. Following restoration, the teeth were submitted to thermal cycling. The teeth were subsequently immersed in 2% rhodamine B dye under vacuum for 48 hours and sectioned to allow the assessment of microleakage under stereomicroscope. The values were tabulated and the results were statistically analyzed using analysis of variance (ANOVA), Tukey's post hoc test and Kruskal-Wallis test. Amalgam with type I GIC showed the least leakage with no statistically significant difference (P value 0.226) when compared to amalgam with Panavia F 2.0 and amalgam with varnish (P value 0.107). It can be concluded that bonded amalgam with type I GIC is a good alternative to amalgam with resin cement (Panavia F 2.0) and amalgam with varnish for large restorations, with the added advantages of GICs. Bonded amalgam restorations prevent over-preparation and reduce the tooth flexure. GIC type I under amalgam provides chemical bonding in between amalgam and tooth structure and thus reduces the microleakage.

Dental hygiene work in a clinical trial.

PubMed

Luís, H S; Morgado, I; Assunção, V; Bernardo, M F; Leroux, B; Martin, M D; DeRouen, T A; Leitão, J

2008-08-01

Dental hygiene activities were developed as part of a randomized clinical trial designed to assess the safety of low-level mercury exposure from dental amalgam restorations. Along with dental-hygiene clinical work, a community programme was implemented after investigators noticed the poor oral hygiene habits of participants, and the need for urgent action to minimize oral health problems in the study population. Clinical and community activity goal was to promote oral health and prevent new disease. Community activities involved participants and their fellow students and were aimed at providing education on oral health in a school environment. Dental hygienists developed clinical work with prophylaxis, sealants application and topical fluoride and implemented the community programme with in-class sessions on oral health themes. Twice a month fluoride mouthrinses and bi-annual tooth brushing instructional activity took place. Participation at dental-hygiene activities, sealed teeth with no need of restoration and dental-plaque-index were measures used to evaluate success of the programme for the participants. Improvement in dental hygiene is shown by the decrease in dental plaque index scores (P < 0.0001); also sealants integrity is achieved in 86.3% of teeth. 888 (13.7%) teeth with sealants had to be restored or were lost. Children participated actively on dental hygiene activities. Teachers became aware of the problem and included oral-health in school curricula. Dental hygiene activities have shown to be helpful to promote dental hygiene, promote oral health and to provide school-age children with education on habits that will be important for their future good health.

Dental Calculus Arrest of Dental Caries.

PubMed

Keyes, Paul H; Rams, Thomas E

An inverse relationship between dental calculus mineralization and dental caries demineralization on teeth has been noted in some studies. Dental calculus may even form superficial layers over existing dental caries and arrest their progression, but this phenomenon has been only rarely documented and infrequently considered in the field of Cariology. To further assess the occurrence of dental calculus arrest of dental caries, this study evaluated a large number of extracted human teeth for the presence and location of dental caries, dental calculus, and dental plaque biofilms. A total of 1,200 teeth were preserved in 10% buffered formal saline, and viewed while moist by a single experienced examiner using a research stereomicroscope at 15-25× magnification. Representative teeth were sectioned and photographed, and their dental plaque biofilms subjected to gram-stain examination with light microscopy at 100× magnification. Dental calculus was observed on 1,140 (95%) of the extracted human teeth, and no dental carious lesions were found underlying dental calculus-covered surfaces on 1,139 of these teeth. However, dental calculus arrest of dental caries was found on one (0.54%) of 187 evaluated teeth that presented with unrestored proximal enamel caries. On the distal surface of a maxillary premolar tooth, dental calculus mineralization filled the outer surface cavitation of an incipient dental caries lesion. The dental calculus-covered carious lesion extended only slightly into enamel, and exhibited a brown pigmentation characteristic of inactive or arrested dental caries. In contrast, the tooth's mesial surface, without a superficial layer of dental calculus, had a large carious lesion going through enamel and deep into dentin. These observations further document the potential protective effects of dental calculus mineralization against dental caries.

Dental Calculus Arrest of Dental Caries

PubMed Central

Keyes, Paul H.; Rams, Thomas E.

2016-01-01

Background An inverse relationship between dental calculus mineralization and dental caries demineralization on teeth has been noted in some studies. Dental calculus may even form superficial layers over existing dental caries and arrest their progression, but this phenomenon has been only rarely documented and infrequently considered in the field of Cariology. To further assess the occurrence of dental calculus arrest of dental caries, this study evaluated a large number of extracted human teeth for the presence and location of dental caries, dental calculus, and dental plaque biofilms. Materials and methods A total of 1,200 teeth were preserved in 10% buffered formal saline, and viewed while moist by a single experienced examiner using a research stereomicroscope at 15-25× magnification. Representative teeth were sectioned and photographed, and their dental plaque biofilms subjected to gram-stain examination with light microscopy at 100× magnification. Results Dental calculus was observed on 1,140 (95%) of the extracted human teeth, and no dental carious lesions were found underlying dental calculus-covered surfaces on 1,139 of these teeth. However, dental calculus arrest of dental caries was found on one (0.54%) of 187 evaluated teeth that presented with unrestored proximal enamel caries. On the distal surface of a maxillary premolar tooth, dental calculus mineralization filled the outer surface cavitation of an incipient dental caries lesion. The dental calculus-covered carious lesion extended only slightly into enamel, and exhibited a brown pigmentation characteristic of inactive or arrested dental caries. In contrast, the tooth's mesial surface, without a superficial layer of dental calculus, had a large carious lesion going through enamel and deep into dentin. Conclusions These observations further document the potential protective effects of dental calculus mineralization against dental caries. PMID:27446993

Novel Amalgams for In-Space Fabrication of Replacement Parts

NASA Technical Reports Server (NTRS)

Cochran, Calvin T.; Van Hoose, James R.; Grugel, R. N.

2012-01-01

Being able to fabricate replacement parts during extended space flight missions precludes the weight, storage volume, and speculation necessary to accommodate spares. Amalgams, widely used in dentistry, are potential candidates for fabricating parts in microgravity environments as they are moldable, do not require energy for melting, and do not pose fluid handling problems. Unfortunately, amalgams have poor tensile strength and the room temperature liquid component is mercury. To possibly resolve these issues a gallium-indium alloy was substituted for mercury and small steel fibers were mixed in with the commercial alloy powder. Subsequent microscopic examination of the novel amalgam revealed complete bonding of the components, and mechanical testing of comparable samples showed those containing steel fibers to have a significant improvement in strength. Experimental procedures, microstructures, and test results are presented and discussed in view of further improving properties.

Preferences of parents of children with autism spectrum disorders concerning oral health and dental treatment.

PubMed

Capozza, Lauren E; Bimstein, Enrique

2012-01-01

The purpose of this study was to describe the preferences of parents of children with or without autism spectrum disorders (ASDs) concerning oral health and dental treatment. A questionnaire that queried demographics, dental needs, perceptions of dental materials and treatments, and parental concerns regarding relevant ASD issues in medicine and dentistry was distributed in the waiting rooms of a pediatric dental clinic and an autism clinic to parents or legal guardians of children undergoing treatment. The responses for the children with or without ASDs were compared. Statistically significant differences between the ASDs (N=23) and non-ASDs (N=33) groups existed for: parental age; frequency of dental visits per year; supervision of tooth-brushing; and use of a fluoridated toothpaste. Statistically insignificant differences were found in attitudes toward: amalgam; composite; fluoride products; or behavior guidance techniques. Parents or legal guardians of children with autism spectrum disorders are likely to have special beliefs and preferences regarding dental materials and dental behavior guidance.

Occlusal glass ionomer cermet, resin sandwich and amalgam restorations: a 2-year clinical study.

PubMed

Lidums, A; Wilkie, R; Smales, R

1993-08-01

This study compared the clinical behavior of a glass ionomer silver cermet (Ketac-Silver), a posterior resin composite (Visio-Molar) used with the "sandwich" technique, and a high-copper amalgam (Dispersalloy) for restoring conventional Class I occlusal cavity preparations. Two dentists placed 116 restorations in the posterior permanent teeth of 35 adults treated at a dental hospital. Restorations were assessed at 6-month intervals over 2 years for bulk loss of material and occlusal wear, surface voids, roughness and cracking, surface and marginal staining, and marginal fracture. Losses of material and surface voids were obvious with the cermet material, with surface crazing or cracking being present in 33% of the restorations. The cermet cannot be recommended as a long-term permanent restorative material if the restorations are likely to be subjected to heavy occlusal stresses and abrasive wear.

21 CFR 872.3820 - Root canal filling resin.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Root canal filling resin. 872.3820 Section 872.3820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification...

Risk factors and prevalence of dental fluorosis and dental caries in school children of North India.

PubMed

Plaka, Kavita; Ravindra, Khaiwal; Mor, Suman; Gauba, Krishan

2017-01-01

The aim of the study was to assess the prevalence of dental fluorosis, dental caries, and associated risk factors in the school children of district Fatehgarh Sahib, Punjab, India, using a cross-sectional study design. Oral health status of children aged between 8 and 15 years was assessed using World Health Organization (WHO) 2013 criteria. Dental fluorosis was assessed using Dean's index, and dental caries were recorded using decayed, missing, filled/decayed, extracted, filled (DMF/def) indices. Four hundred school children were examined, of which 207 were in the 8-11-year-old group and 193 were in the 12-15-year-old group. The overall prevalence of dental fluorosis was 4.1%, which might be linked to a high concentration of fluoride in drinking water at certain locations of rural Punjab. The prevalence of dental caries was 36.5% with a mean DMF score of 0.3 and def score of 0.6. Risk factors for dental caries include oral hygiene behavior and sugar consumption patterns. The study highlights the need to increase awareness about the oral health and hygiene among the school children in India.

Selective interference with pacemaker activity by electrical dental devices.

PubMed

Miller, C S; Leonelli, F M; Latham, E

1998-01-01

We sought to determine whether electromagnetic interference with cardiac pacemakers occurs during the operation of contemporary electrical dental equipment. Fourteen electrical dental devices were tested in vitro for their ability to interfere with the function of two Medtronics cardiac pacemakers (one a dual-chamber, bipolar Thera 7942 pacemaker, the other a single-chamber, unipolar Minix 8340 pacemaker). Atrial and ventricular pacemaker output and electrocardiographic activity were monitored by means of telemetry with the use of a Medtronics 9760/90 programmer. Atrial and ventricular pacing were inhibited by electromagnetic interference produced by the electrosurgical unit up to a distance of 10 cm, by the ultrasonic bath cleaner up to 30 cm, and by the magnetorestrictive ultrasonic scalers up to 37.5 cm. In contrast, operation of the amalgamator, electric pulp tester, composite curing light, dental handpieces, electric toothbrush, microwave oven, dental chair and light, ENAC ultrasonic instrument, radiography unit, and sonic scaler did not alter pacing rate or rhythm. These results suggest that certain electrosurgical and ultrasonic instruments may produce deleterious effects in medically fragile patients with cardiac pacemakers.

A Novel Characterization of Amalgamated Networks in Natural Systems

PubMed Central

Barranca, Victor J.; Zhou, Douglas; Cai, David

2015-01-01

Densely-connected networks are prominent among natural systems, exhibiting structural characteristics often optimized for biological function. To reveal such features in highly-connected networks, we introduce a new network characterization determined by a decomposition of network-connectivity into low-rank and sparse components. Based on these components, we discover a new class of networks we define as amalgamated networks, which exhibit large functional groups and dense connectivity. Analyzing recent experimental findings on cerebral cortex, food-web, and gene regulatory networks, we establish the unique importance of amalgamated networks in fostering biologically advantageous properties, including rapid communication among nodes, structural stability under attacks, and separation of network activity into distinct functional modules. We further observe that our network characterization is scalable with network size and connectivity, thereby identifying robust features significant to diverse physical systems, which are typically undetectable by conventional characterizations of connectivity. We expect that studying the amalgamation properties of biological networks may offer new insights into understanding their structure-function relationships. PMID:26035066

Volatile methacrylates in dental practices.

PubMed

Marquardt, Wolfgang; Seiss, Mario; Hickel, Reinhard; Reichl, Franz X

2009-04-01

In recent years, an increase of occupational respiratory diseases, such as asthma caused by methacrylates, has been observed in dental personnel. In this study, the exposure of dental personnel to various volatile methacrylates was investigated. The air levels of methacrylates were measured during filling treatment while bonding agents were used in 4 dental practices in Munich, Germany. Short-term air sampling (15 min) was performed using solid phase microextraction (SPME). The SPME fibers were coated with carbowax/divinyl benzene to enrich the analytes. For analysis, the analytes were thermically desorbed from the fiber and subsequently analyzed directly by gas chromatography/mass spectrometry. The methacrylates methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA), ethylene glycol dimethacrylate (EGDMA), and triethylene glycol dimethacrylate (TEG-DMA) were identified in the air of dental practices. The exposure levels of the four methacrylates varied during the filling treatments. The maximum concentrations found were 0.4 mg/m3 for MMA, 45 microg/m3 for HEMA, 13 microg/m3 for EGDMA, and 45 microg/m3 for TEG-DMA. The detection of TEG-DMA correlated with the application of bonding agents during performance of dental fillings. Exposure levels of different methacrylates were observed at all investigated dental practices. The maximum levels of MMA measured in this study were at least 200 times lower than the toxicologically relevant maximum allowable concentrations defined in various countries. Nevertheless, the exposure levels of methacrylates should be kept as low as possible due to the allergenic potential of some methacrylates.

Dental Composite Restorations and Neuropsychological Development in Children: Treatment Level Analysis from a Randomized Clinical Trial

PubMed Central

Maserejian, Nancy N.; Trachtenberg, Felicia L.; Hauser, Russ; McKinlay, Sonja; Shrader, Peter; Bellinger, David C.

2012-01-01

Background Resin-based dental restorations may intra-orally release their components and bisphenol A. Gestational bisphenol A exposure has been associated with poorer executive functioning in children. Objectives To examine whether exposure to resin-based composite restorations is associated with neuropsychological development in children. Methods Secondary analysis of treatment level data from the New England Children’s Amalgam Trial, a 2-group randomized safety trial conducted from 1997–2006. Children (N=534) aged 6–10 y with >2 posterior tooth caries were randomized to treatment with amalgam or resin-based composites (bisphenol-A-diglycidyl-dimethacrylate-composite for permanent teeth; urethane dimethacrylate-based polyacid-modified compomer for primary teeth). Neuropsychological function at 4- and 5-year follow-up (N=444) was measured by a battery of tests of executive function, intelligence, memory, visual-spatial skills, verbal fluency, and problem-solving. Multivariable generalized linear regression models were used to examine the association between composite exposure levels and changes in neuropsychological test scores from baseline to follow-up. For comparison, data on children randomized to amalgam treatment were similarly analyzed. Results With greater exposure to either dental composite material, results were generally consistent in the direction of slightly poorer changes in tests of intelligence, achievement or memory, but there were no statistically significant associations. For the four primary measures of executive function, scores were slightly worse with greater total composite exposure, but statistically significant only for the test of Letter Fluency (10-surface-years β= −0.8, SE=0.4, P=0.035), and the subtest of color naming (β= −1.5, SE=0.5, P=0.004) in the Stroop Color-Word Interference Test. Multivariate analysis of variance confirmed that the negative associations between composite level and executive function were not

Effect of iodine on mercury concentrations in dental-unit wastewater.

PubMed

Stone, Mark E; Kuehne, John C; Cohen, Mark E; Talbott, Jonathan L; Scott, John W

2006-02-01

This study was undertaken to determine whether iodine used to control bacteria in dental unit waterlines could increase mercury concentrations in dental wastewater. The study was conducted in four parts. Part 1. Solutions containing iodine in concentrations ranging from zero (control) to 20 mg/L were mixed with ground and sieved dental amalgam and then allowed to equilibrate by settling. Cold vapor atomic absorption spectrometry was used to determine mercury levels in the settled supernatants at 24 h and at 7 days. Part 2. Deionized water was pumped through an iodine-releasing water-treatment cartridge, collected, and mixed with ground and sieved dental amalgam. Mercury levels in settled supernatants were measured at 24 h and at 7 days. Part 3. Iodine in water from two commercial iodine-releasing cartridges was measured using Inductively Couple Plasma Mass Spectrometry. Part 4. Baseline mercury levels in settled supernatants from wastewater collected from two dental chairs were compared to samples taken from chairs equipped with iodine-releasing cartridges. Part 1. A linear correlation between iodine and mercury concentration (r2=0.9167 and 0.9459, respectively, both P<0.001) was seen at both 24 h and 7 days. Part 2. Mean mercury levels in 24h samples were 3.0 times higher than the controls (0.2864 mg/L compared with 0.0939mg/L for the 24 h controls). Mean mercury levels in the 7-day samples were 5.9 times higher than the 7-day controls (0.2048 mg/L compared with 0.0348 mg/L for the 7-day controls). Part 3. The effluent from two iodine-releasing cartridges showed iodine concentrations averaging 3.2 mg/L (n=10, SD=0.8, range=2.5-4.6). Part 4. Data from the clinical study showed a statistically significant 2.5-fold increase in mercury levels with iodine-containing samples compared to baseline (0.0853 mg/L, n=18, SD=0.0441 and 0.0345 mg/L, n=18, SD=0.0145, respectively; P<0.001). Data suggest that iodine can increase concentrations of dissolved mercury in dental unit

The impact of a continuing education programme on the adoption of nickel-titanium rotary instrumentation and root-filling quality amongst a group of Swedish general dental practitioners.

PubMed

Dahlström, L; Molander, A; Reit, C

2015-02-01

The aim of the study was to test the hypothesis that a further education programme relating to nickel-titanium rotary instrumentation (NTRI), with the concurrent activation of social/professional networks amongst all general dental practitioners (GDPs) in a public dental service in Sweden, would increase the adoption rate and improve root-filling quality. To activate the networks, the GDPs at the 25 clinics elected training coaches from amongst themselves. The coaches were educated by a specialist and were then free to organise and conduct the training of the local GDPs. However, collective hands-on training and discussions were mandatory. Lectures were held by an endodontist. The rate of adoption and root-filling quality was evaluated just before and 6 months after the education. Statistical tests were performed with chi-square using a 95% confidence interval. Nickel-titanium rotary instrumentation was adopted by 88%. Excellent root fillings (score 1) increased from 45% to 59% (P = 0.003). The rate of poor-quality root fillings (score 4 and score 5) was not affected. The quality ratio (score 1/score 5) increased from 5.36 (118/22) to 9.5 (133/14). Eleven dentists (17%) at nine different clinics produced 49% of the poor-quality root fillings (score 4 and score 5). Seventy-three per cent of these dentists stated that they had adopted NTRI. The introduction of NTRI will increase the adoption rate and the frequency of good-quality root fillings. However, it will not overcome the problems associated with dentists producing a low-quality level, even if a local professional network is activated. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Electrolytic method for the production of lithium using a lithium-amalgam electrode

DOEpatents

Cooper, John F.; Krikorian, Oscar H.; Homsy, Robert V.

1979-01-01

A method for recovering lithium from its molten amalgam by electrolysis of the amalgam in an electrolytic cell containing as a molten electrolyte a fused-salt consisting essentially of a mixture of two or more alkali metal halides, preferably alkali metal halides selected from lithium iodide, lithium chloride, potassium iodide and potassium chloride. A particularly suitable molten electrolyte is a fused-salt consisting essentially of a mixture of at least three components obtained by modifying an eutectic mixture of LiI-KI by the addition of a minor amount of one or more alkali metal halides. The lithium-amalgam fused-salt cell may be used in an electrolytic system for recovering lithium from an aqueous solution of a lithium compound, wherein electrolysis of the aqueous solution in an aqueous cell in the presence of a mercury cathode produces a lithium amalgam. The present method is particularly useful for the regeneration of lithium from the aqueous reaction products of a lithium-water-air battery.

The problem of motivating teaching staff in a complex amalgamation.

PubMed

Kenrick, M A

1993-09-01

This paper addresses some of the problems brought about by the merger of a number of schools of nursing into a new complex amalgamation. A very real concern in the new colleges of nursing and midwifery in the United Kingdom is the effect of amalgamation on management systems and staff morale. The main focus of this paper is the motivation of staff during this time of change. There is currently a lack of security amongst staff and in many instances the personal job satisfaction of nurse teachers and managers of nurse education has been reduced, which has made the task of motivating staff difficult. Hence, two major theories of motivation and the implications of these theories for managers of nurse education are discussed. The criteria used for the selection of managers within the new colleges, leadership styles and organizational structures are reviewed. The amalgamations have brought about affiliation with higher-education institutions. Some problems associated with these mergers and the effects on the motivation of staff both within the higher-education institutions and the nursing colleges are outlined. Strategies for overcoming some of the problems are proposed including job enlargement, job enrichment, potential achievement rewards and the use of individual performance reviews which may be useful for assessing the ability of all staff, including managers, in the new amalgamations.

Health maintenance facility: Dental equipment requirements

NASA Technical Reports Server (NTRS)

Young, John; Gosbee, John; Billica, Roger

1991-01-01

The objectives were to test the effectiveness of the Health Maintenance Facility (HMF) dental suction/particle containment system, which controls fluids and debris generated during simulated dental treatment, in microgravity; to test the effectiveness of fiber optic intraoral lighting systems in microgravity, while simulating dental treatment; and to evaluate the operation and function of off-the-shelf dental handheld instruments, namely a portable dental hand drill and temporary filling material, in microgravity. A description of test procedures, including test set-up, flight equipment, and the data acquisition system, is given.

Review of Spaceflight Dental Emergencies

NASA Technical Reports Server (NTRS)

Menon, Anil

2012-01-01

All exploration class missions--extending beyond earth's orbit--differ from existing orbital missions by being of longer duration and often not having a means of evacuation. If an exploration mission extends beyond a year, then there will be a greater lapse since the crewmembers last terrestrial dental exams, which routinely occur each year. This increased time since professional dental care could increase the chance of a dental emergency such as intractable pain, dental decay requiring a temporary filling, crown replacement, exposed pulp, abscess, tooth avulsion, or toothache. Additionally, any dental emergency will have to be treated in-flight with available resources and personnel who may not have extensive training in dental care. Thus, dental emergencies are an important risk to assess in preparation for exploration missions.

Determination of minimum suction level necessary for field dental units.

PubMed

Charlton, David G

2010-04-01

A significant problem with most field dental units is that their suction is too weak to effectively remove debris from the mouth. The purpose of this study was to determine the minimum clinically acceptable suction level for routine dentistry. A vacuum pump was connected to a high-volume dental evacuation line in a simulated clinical setting and different suction airflow rates were evaluated by nine evaluator dentists for their capability to effectively remove amalgam debris and water. Airflow levels were rated as "clinically acceptable" or "clinically unacceptable" by each evaluator. Data were analyzed using a chi2 test for trend. Analysis indicated a significant linear trend between airflow and ratings (p < 0.0001). The first airflow level considered by all evaluators as producing clinically acceptable suction was 4.5 standard cubic feet per minute (0.127 standard cubic meters per minute). This value should be the minimum level required for all military field dental units.

The effect of occupational exposure to mercury vapour on the fertility of female dental assistants.

PubMed Central

Rowland, A S; Baird, D D; Weinberg, C R; Shore, D L; Shy, C M; Wilcox, A J

1994-01-01

Exposure to mercury vapour or inorganic mercury compounds can impair fertility in laboratory animals. To study the effects of mercury vapour on fertility in women, eligibility questionnaires were sent to 7000 registered dental assistants in California. The final eligible sample of 418 women, who had become pregnant during the previous four years, were interviewed by telephone. Detailed information was collected on mercury handling practices and the number of menstrual cycles without contraception it had taken them to become pregnant. Dental assistants not working with amalgam served as unexposed controls. Women with high occupational exposure to mercury were less fertile than unexposed controls. The fecundability (probability of conception each menstrual cycle) of women who prepared 30 or more amalgams per week and who had five or more poor mercury hygiene factors was only 63% of that for unexposed women (95% CI 42%-96%) after controlling for covariates. Women with low exposure were more fertile, however, than unexposed controls. Possible explanations for the U shaped dose response and limitations of the exposure measure are discussed. Further investigation is needed that uses biological measures of mercury exposure. PMID:8124459

Assessment of the quality of reporting observational studies in the pediatric dental literature.

PubMed

Butani, Yogita; Hartz, Arthur; Levy, Steven; Watkins, Catherine; Kanellis, Michael; Nowak, Arthur

2006-01-01

The purpose of this assessment was to evaluate reporting of observational studies in the pediatric dental literature. This assessment included the following steps: (1) developing a model for reporting information in clinical dentistry studies; (2) identifying treatment comparisons in pediatric dentistry that were evaluated by at least 5 observational studies; (3) abstracting from these studies any data indicated by applying the reporting model; and (4) comparing available data elements to the desired data elements in the reporting model. The reporting model included data elements related to: (1) patients; (2) providers; (3) treatment details; and (4) study design. Two treatment comparisons in pediatric dentistry were identified with 5 or more observational studies: (1) stainless steel crowns vs amalgams (10 studies); and (2) composite restorations vs amalgam (5 studies). Results from studies comparing the same treatments varied substantially. Data elements from the reporting model that could have explained some of the variation were often reported inadequately or not at all. Reporting of observational studies in the pediatric dental literature may be inadequate for an informed interpretation of the results. Models similar to that used in this study could be used for developing standards for the conduct and reporting of observational studies in pediatric dentistry.

Brushing up on the history of intermetallics in dentistry

NASA Astrophysics Data System (ADS)

Waterstrat, Richard M.

1990-03-01

Employing a silver-tin-mercury intermetallic to repair cavities may seem a little unusual, but intermetallics are quite common in dentistry, ranging from gold crowns to braces. Although the human mouth can be unfriendly territory for a brittle intermetallic alloy, dental amalgam has been around since 659 A.D., and its technology has been developed to the point where a filling can be expected to last 30 years or more.

Real-Time Plasmonic Monitoring of Single Gold Amalgam Nanoalloy Electrochemical Formation and Stripping.

PubMed

Wang, Jun-Gang; Fossey, John S; Li, Meng; Xie, Tao; Long, Yi-Tao

2016-03-01

Direct electrodeposition of mercury onto gold nanorods on an ITO substrate, without reducing agents, is reported. The growth of single gold amalgam nanoalloy particles and subsequent stripping was monitored in real-time monitoring by plasmonic effects and single-nanoparticle dark-field spectroelectrochemistry techniques. Time-dependent scattering spectral information conferred insight into the growth and stripping mechanism of a single nanoalloy particle. Four critical stages were observed: First, rapid deposition of Hg atoms onto Au nanorods; second, slow diffusion of Hg atoms into Au nanorods; third, prompt stripping of Hg atoms from Au nanorods; fourth, moderate diffusion from the inner core of Au nanorods. Under high Hg(2+) concentrations, homogeneous spherical gold amalgam nanoalloys were obtained. These results demonstrate that the morphology and composition of individual gold amalgam nanoalloys can be precisely regulated electrochemically. Moreover, gold amalgam nanoalloys with intriguing optical properties, such as modulated plasmonic lifetimes and quality factor Q, could be obtained. This may offer opportunities to extend applications in photovoltaic energy conversion and chemical sensing.

Dental solid and hazardous waste management and safety practices in developing countries: Nablus district, Palestine.

PubMed

Al-Khatib, Issam A; Monou, Maria; Mosleh, Salem A; Al-Subu, Mohammed M; Kassinos, Despo

2010-05-01

This study investigated the dental waste management practices and safety measures implemented by dentists in the Nablus district, Palestine. A comprehensive survey was conducted for 97 of the 134 dental clinics to assess the current situation. Focus was placed on hazardous waste produced by clinics and the handling, storage, treatment and disposal measures taken. Mercury, found in dental amalgam, is one of the most problematic hazardous waste. The findings revealed that there is no proper separation of dental waste by classification as demanded by the World Health Organization. Furthermore, medical waste is often mixed with general waste during production, collection and disposal. The final disposal of waste ends up in open dumping sites sometimes close to communities where the waste is burned. Correct management and safety procedures that could be effectively implemented in developing countries were examined. It was concluded that cooperation between dental associations, government-related ministries and authorities needs to be established, to enhance dental waste management and provide training and capacity building programs for all professionals in the medical waste management field.

Pediatric dental chair vs. traditional dental chair: a pediatric dentist's poll.

PubMed

Barjatya, Khushboo; Vatsal, Ankur; Kambalimath, Halaswamy V; Kulkarni, Vinay Kumar; Reddy, Naveen Banda

2015-01-01

Proper positioning of the child patient, can not only have positive ramifications for the operator's posture, comfort, and career longevity - it can also lead to better treatment and increased productivity. The aim of the survey questionnaire was to assess the utilization, need, and attitude concerning dental chairs among pediatric dentist while working on and managing the child patient. The questions were structured using adobe forms central online software, regarding the user-friendliness of pediatric dental chair vs. traditional adult dental chair available in the market. Our result shows that out of 337 respondents, 79% worked on pediatric dental chair, whereas 21% had no experience of it. Of these 79% pediatric dentist, 48% preferred pediatric dental chair. But pediatric dental problem still has certain disadvantages like higher cost, leg space problem, lower availability, etc. During the research it was found that ergonomics and usability issues were the main problems. Thus, pediatric dental chair is not so popular in the current scenario. This study allowed for general ideas for the improvement of dental chairs and thus improved dental chair would fill the gap in the current scenario.

NORAD, USNORTHCOM and the Mexican Air Force to participate in AMALGAM EAGLE

Science.gov Websites

. Northern Command (USNORTHCOM), will participate, with the Mexican Air Force, in AMALGAM EAGLE 15, a the Mexican Air Force to participate in AMALGAM EAGLE 15 N-NC Public Affairs PRINT | E-MAIL PETERSON tactical exercise, to be conducted Jun.30 - Jul.2, 2015, in which Mexico and the United States will respond

Dental anxiety and regularity of dental attendance in younger adults.

PubMed

Quteish Taani, D S M

2002-06-01

Dental anxiety constitutes a major problem for patients and dental care providers alike. The aim of this study was to examine the relationship between dental anxiety and regularity of dental attendance among young adults. A random sample of 15 course directors (1:50) was asked to participate in the study. Of these, only 10 course-directors agreed to handout the 500 questionnaires. All undergraduate students who participated in this study were asked to complete a questionnaire modified from Dental Fear Survey (DFS) questionnaire and 368 (73.6%) filled forms were returned for statistical analysis. The results showed that only 20.9% were regular dental attendee while the majority (79.1%) were irregular attendee. The reasons given for irregular attendance were 'lack of time' (36%), 'treatment not needed' (34.1%), 'fear from dentist' (13.3%) and 'cost' (16.6%). The sight and sensation of the injection and sight, sound, and sensation of the drill were the most common fear-eliciting stimuli. Increased heart rate was the commonest reported physiological response. Females had higher mean ratings, therefore tended to be more anxious than males. Dental anxiety represented by the mean responses to the items, was found to be higher in irregular dental attendee than regular attendee. In conclusion, this suggests that dental anxiety may affect the seeking of dental care, therefore to be taken into account when training dental care providers.

Understanding the mercury reduction issue: the impact of mercury on the environment and human health.

PubMed

Kao, Richard T; Dault, Scott; Pichay, Teresa

2004-07-01

Mercury has been used in both medicine and dentistry for centuries. Recent media attention regarding the increased levels of mercury in dietary fish, high levels of mercury in air emissions, and conjecture that certain diseases may be caused by mercury exposure has increased public awareness of the potential adverse health effects of high doses of mercury. Dentistry has been criticized for its continued use of mercury in dental amalgam for both public health and environmental reasons. To address these concerns, dental professionals should understand the impact of the various levels and types of mercury on the environment and human health. Mercury is unique in its ability to form amalgams with other metals. Dental amalgam--consisting of silver, copper, tin, and mercury--has been used as a safe, stable, and cost-effective restorative material for more than 150 years. As a result of this use, the dental profession has been confronted by the public on two separate health issues concerning the mercury content in amalgam. The first issue is whether the mercury amalgamated with the various metals to create dental restorations poses a health issue for patients. The second is whether the scraps associated with amalgam placement and the removal of amalgam restorations poses environmental hazards which may eventually have an impact on human health. Despite the lack of scientific evidence for such hazards, there is growing pressure for the dental profession to address these health issues. In this article, the toxicology of mercury will be reviewed and the impact of amalgam on health and the environment will be examined.

An atraumatic restorative treatment (ART) technique: evaluation after one year.

PubMed

Frencken, J E; Songpaisan, Y; Phantumvanit, P; Pilot, T

1994-10-01

Extraction is the most common dental treatment provided for people in rural and suburban areas in many less-industrialised countries. By comparison, restorative care is rarely provided. In order to improve such situations, a treatment technique has been developed based only on hand excavation of carious lesions and using glass-ionomer cement as a filling material and a sealant. This Atraumatic Restorative Treatment (ART) technique follows the concept of minimal intervention and does not require electrically driven equipment. This paper reports on the longevity of fillings and sealants placed using the technique under field conditions in rural Thailand. Dental caries was treated using the ART technique in one village, whilst the population in a second village received restorative care (amalgam fillings) through mobile dental units. A third village was the control. After one year, 79 per cent of single surface ART fillings and 55 per cent of ART fillings of greater than one surface placed in deciduous teeth were judged successful. The success rate of ART fillings in the permanent dentition (mainly single surface fillings) was 93 per cent and the retention rate for sealants was 78 per cent. Children were pleased at having received treatment by this technique and showed little fear. The ART technique is a promising caries treatment procedure for use in rural and sub-urban areas in less-industrialised countries.

Biocompatibility of root-end filling materials: recent update

PubMed Central

Gupta, Saurabh Kumar; Newaskar, Vilas

2013-01-01

The purpose of a root-end filling is to establish a seal between the root canal space and the periradicular tissues. As root-end filling materials come into contact with periradicular tissues, knowledge of the tissue response is crucial. Almost every available dental restorative material has been suggested as the root-end material of choice at a certain point in the past. This literature review on root-end filling materials will evaluate and comparatively analyse the biocompatibility and tissue response to these products, with primary focus on newly introduced materials. PMID:24010077

[A study of different polishing techniques for amalgams and glass-cermet cement by scanning electron microscope (SEM)].

PubMed

Kakaboura, A; Vougiouklakis, G; Argiri, G

1989-01-01

Finishing and polishing an amalgam restoration, is considered as an important and necessary step of the restorative procedure. Various polishing techniques have been recommended to success a smooth amalgam surface. The aim of this study was to investigate the influence of three different polishing treatments on the marginal integrity and surface smoothness of restorations made of three commercially available amalgams and a glass-cermet cement. The materials used were the amalgams, Amalcap (Vivadent), Dispersalloy (Johnson and Johnson), Duralloy (Degussa) and the glass-cermet Katac-Silver (ESPE). The occlusal surfaces of the restorations were polished by the methods: I) round bur, No4-rubber cup-zinc oxide paste in a small brush, II) round bur No 4-bur-brown, green and super green (Shofu) polishing cups and points successively and III) amalgam polishing bur of 12-blades-smooth amalgam polishing bur. Photographs from unpolished and polished surfaces of the restorations, were taken with scanning electron microscope, to evaluate the polishing techniques. An improvement of marginal integrity and surface smoothness of all amalgam restorations was observed after the specimens had been polished with the three techniques. Method II, included Shofu polishers, proved the best results in comparison to the methods I and III. Polishing of glass-cermet cement was impossible with the examined techniques.

Amalgam shear bond strength to dentin using single-bottle primer/adhesive systems.

PubMed

Cobb, D S; Denehy, G E; Vargas, M A

1999-10-01

To evaluate the in vitro shear bond strengths (SBS) of a spherical amalgam alloy (Tytin) to dentin using several single-bottle primer/adhesive systems both alone: Single Bond (SB), OptiBond Solo (Sol), Prime & Bond 2.1 (PB), One-Step (OS) and in combination with the manufacturer's supplemental amalgam bonding agent: Single Bond w/3M RelyX ARC (SBX) and Prime & Bond 2.1 w/Amalgam Bonding Accessory Kit (PBA). Two, three-component adhesive systems, Scotchbond Multi-Purpose (SBMP) and Scotchbond Multi-Purpose Plus w/light curing (S + V) and w/o light curing (S+) were used for comparison. One hundred eight extracted human third molars were mounted lengthwise in phenolic rings with acrylic resin. The proximal surfaces were ground to expose a flat dentin surface, then polished to 600 grit silicon carbide paper. The teeth were randomly assigned to 9 groups (n = 12), and dentin surfaces in each group were treated with an adhesive system according to the manufacturer's instructions, except for S + V specimens, where the adhesive was light cured for 10 s before placing the amalgam. Specimens were then secured in a split Teflon mold, having a 3 mm diameter opening and amalgam was triturated and condensed onto the treated dentin surfaces. Twenty minutes after condensation, the split mold was separated. Specimens were placed in distilled water for 24 hrs, then thermocycled (300 cycles, between 5 degrees C and 55 degrees C, with 12 s dwell time). All specimens were stored in 37 degrees C distilled water for 7 days, prior to shear strength testing using a Zwick Universal Testing Machine at a cross-head speed of 0.5 mm/min. The highest to the lowest mean dentin shear bond strength values (MPa) for the adhesive systems tested were: S + V (10.3 +/- 2.3), SBX (10.2 +/- 3.5), PBA, (6.4 +/- 3.6), SOL (5.8 +/- 2.5), SBMP (5.7 +/- 1.8), S+ (4.8 +/- 2.3), PB (2.7 +/- 2.6), SB (2.7 +/- 1.1) and OS (2.5 +/- 1.8). One-way ANOVA and Duncan's Multiple Range Test indicated significant

Effect of Self-etch Adhesives on Self-sealing Ability of High-Copper Amalgams

PubMed Central

Moazzami, Saied Mostafa; Moosavi, Horieh; Moddaber, Maryam; Parvizi, Reza; Moayed, Mohamad Hadi; Mokhber, Nima; Meharry, Michael; B Kazemi, Reza

2016-01-01

Statement of the Problem: Similar to conventional amalgam, high-copper amalgam alloy may also undergo corrosion, but it takes longer time for the resulting products to reduce microleakage by sealing the micro-gap at the tooth/amalgam interface. Purpose: The aim of this study was to evaluate the effect of self-etch adhesives with different pH levels on the interfacial corrosion behavior of high-copper amalgam restoration and its induction potential for self-sealing ability of the micro-gap in the early hours after setting by means of Electro-Chemical Tests (ECTs). Materials and Method: Thirty cylindrical cavities of 4.5mm x 4.7mm were prepared on intact bicuspids. The samples were divided into five main groups of application of Adhesive Resin (AR)/ liner/ None (No), on the cavity floor. The first main group was left without an AR/ liner (No). In the other main groups, the types of AR/ liner used were I-Bond (IB), Clearfil S3 (S3), Single Bond (SB) and Varnish (V). Each main group (n=6) was divided into two subgroups (n=3) according to the types of the amalgams used, either admixed ANA 2000 (ANA) or spherical Tytin (Tyt). The ECTs, Open Circuit Potential (OCP), and the Linear Polarization Resistance (LPR) for each sample were performed and measured 48 hours after the completion of the samples. Results: The Tyt-No and Tyt-IB samples showed the highest and lowest OCP values respectively. In LPR tests, the Rp values of ANA-V and Tyt-V were the highest (lowest corrosion rate) and contrarily, the ANA-IB and Tyt-IB samples, with the lowest pH levels, represented the lowest Rp values (highest corrosion rates). Conclusion: Some self-etch adhesives may increase interfacial corrosion potential and self-sealing ability of high-copper amalgams. PMID:27942548

A revised classification and terminology for stacked and amalgamated turbidites in environments dominated by (hemi)pelagic sedimentation

NASA Astrophysics Data System (ADS)

Van Daele, Maarten; Meyer, Inka; Moernaut, Jasper; De Decker, Steven; Verschuren, Dirk; De Batist, Marc

2017-07-01

Stacked or amalgamated turbidites provide an opportunity to infer the synchronous triggering of multiple slope failures, which is a criterion often used to attribute these slope failures to earthquake shaking; and such turbidites are thus a proxy for reconstructing long-term earthquake recurrence. However, other processes, such as erosion, reflecting turbidity currents and seiching, may produce similar amalgamated/stacked deposits. Here we study two turbidites from Lake Challa, a crater lake on the lower slopes of Kilimanjaro (Kenya/Tanzania). The occurrence in Lake Challa of both single slope failures and basin-wide landslide events, all accompanied by distal turbidites, provides an excellent opportunity to assess the characteristics and significance of amalgamated/stacked turbidites in an enclosed lake basin with diatomaceous sediments, reflecting hemipelagic sedimentation in offshore areas. We also compare the characteristics of amalgamated/stacked turbidites in basins other than Lake Challa to discuss potential causes of different amalgamation patterns (stacked or multi-pulsed character). The low density and elongated shape of diatom frustules increases grain-to-grain interaction and thereby damps turbulence, resulting in faster bed aggradation and a stacked character of the amalgamated turbidites. Finally, as currently both synchronously and non-synchronously triggered turbidites are in literature referred to as ;stacked turbidite;, we propose a revised terminology that differentiates an ;amalgamated turbidite; from a ;turbidite stack;. In sedimentary environments that are dominated by (hemi)pelagic sedimentation, and where turbidity currents are anomalous events, an ;amalgamated turbidite; can often be shown to be the result of synchronous triggering, while a ;turbidite stack; must always result from a succession of discrete events.

Dental neglect among children in Chennai.

PubMed

Gurunathan, Deepa; Shanmugaavel, Arunachalam Karthikeyan

2016-01-01

Child dental neglect is the failure of a parent or guardian to meet the child's basic oral health needs such that the child enjoys adequate function and freedom from pain and infection, where reasonable resources are available to family or caregiver. The aim of the study is to evaluate the phenomenon of dental neglect among children in Chennai and to associate dental neglect with oral health status of children aged 3-12 years. This is a cross-sectional study involving 478 pairs of parents and children. Dental neglect scale and a questionnaire were used to assess the dental neglect score among parents of the children involved in the study. Oral health status of children was clinically assessed using oral hygiene index, decayed, extracted, filled teeth (def(t)), pulp, ulcers, fistula, abscess (pufa), decayed, missing, filled teeth (DMFT), PUFA as per the World Health Organization criteria and pufa/PUFA index. Student's t-test and one-way ANOVA were used appropriately for statistical analysis using SPSS software version 20.0. A significant higher dental neglect score was reported among the parents who reside in the suburban location (P < 0.001), whose educational qualification was secondary (P < 0.001) and who have not availed any dental service for >3 years (P = 0.001). A significant higher DMFT (P = 0.003), deft (P = 0 < 0.001), pufa (P = 0.011), and debris index (P = 0.002) scores were seen in the higher dental neglect group. Child dental neglect is seen among the parents whose educational qualification was secondary, who reside in the suburban location, and who have not utilized the dental services for more than 3 years in Chennai. This dental neglect results in poorer oral health of children.

Cusp Fracture Resistance of Maxillary Premolars Restored with the Bonded Amalgam Technique Using Various Luting Agents

PubMed Central

Marchan, Shivaughn M.; Coldero, Larry; White, Daniel; Smith, William A. J.; Rafeek, Reisha N.

2009-01-01

Objective. This in vitro study uses measurements of fracture resistance to compare maxillary premolars restored with the bonded amalgam technique using a new resin luting cement, glass ionomer, and resin-modified glass ionomer as the bonding agents. Materials. Eighty-five sound maxillary premolars were selected and randomly assigned to one of five test groups of 17 teeth each. One group of intact teeth served as the control. The remaining groups were prepared to a standard cavity form relative to the dimensions of the overall tooth and restored with amalgam alone or a bonded amalgam using one of three luting agents: RelyX Arc (a new resin luting cement), RelyX luting (a resin-modified glass ionomer), or Ketac-Cem μ (a glass ionomer) as the bonding agents. Each tooth was then subjected to compressive testing until catastrophic failure occurred. The mean loads at failure of each group were statistically compared using ANOVA with a post hoc Bonferroni test. Results. It was found that regardless of the luting cement used for the amalgam bonding technique, there was little effect on the fracture resistance of teeth. Conclusion. Cusp fracture resistance of premolars prepared with conservative MOD cavity preparations is not improved by using an amalgam-bonding technique compared to similar cavities restored with amalgam alone. PMID:20339450

Psychometric Properties of the Croatian Language Version of the Dental Environment Stress Questionnaire on Dental Medicine Students

PubMed Central

Laktić, Martina; Kuftinec, Krešimir; Čelebić, Asja; Kovačić, Ines; Alhajj, Mohamed Nasser

2017-01-01

Objective To develop the Croatian version of the 41-item Dental Environment Stress questionnaire (DES) for stress assessment of dental students in both, preclinical and clinical years of study and to test its psychometric properties in Croatian dental student population. Materials and Methods The English version of the 41-Item DES questionnaire was first translated into the Croatian language. Subsequently, it was set on the google drive and filled out by a total of 202 students from the School of Dental Medicine, University of Zagreb and 30 additional students from other Faculties. Students also assessed their overall level of stress on the Likert scale (1=no stress, 5=highest level of stress). Internal consistency was tested on 202 dental students; test-retest reliability on 30 dental students who filled out the same questionnaire twice; convergent validity on 202 dental students; and divergent validity on 202 dental students and 30 students from faculties not belonging to the biomedicine group. Results Internal consistency showed high Cronbach alpha coefficient (0.9) and test-retest reliability showed no significant difference (P>0.05) within the period of 14 days when stress level had not changed (vacation). Convergent validity was confirmed by the significant association between the DES summary scores and the self- perceived level of stress (Spearman’s rho=0.881; P<0.001). Divergent validity was confirmed by significantly lower DES summary scores in students not belonging to the Biomedicine group (t=7.5, P<0.001). Conclusion Excellent psychometric properties of the Croatian version of the DES questionnaire enable its utilization for assessment of stress level in Croatian dental students. PMID:29225359

Flemish general dental practitioners' knowledge of dental radiology

PubMed Central

Aps, J K M

2010-01-01

The aim of this study was to assess general dental practitioners' knowledge of dental radiography and radiation protection in order to alert the Belgian authorities and dental professional societies. Prior to attending a postgraduate course on intraoral radiology, general dental practitioners in Flanders, Belgium, were asked to fill in a questionnaire regarding the radiological equipment and the techniques they used for intraoral radiography. The availability and type of dental panoramic equipment were also assessed. A total of 374 questionnaires were available for this study. 15% of the attendants used radiographic equipment that was more than 27 years old and 43% reported equipment that operated with a clockwork timer. 32% and 75% respectively had no idea what the kV or mA settings were on their intraoral equipment. 5% were unaware which cone geometry or geometric technique (paralleling or bisecting angle technique) they were using. 81% claimed to be using a short cone technique. 47% did not know what collimation meant, whereas 40% stated that they were using circular collimation. 38% used digital intraoral image detectors (63% were photostimulable storage phosphorplate (PSPP)), but 16% were not sure about the type of sensor they were using (PSPP or solid-state sensors). 61% also had dental panoramic equipment available, 25% of which was digital (10% charge coupled device (CCD) and 15% PSPP). These results clearly indicate the need for continued education on this subject. The latter is an important signal to Belgian authorities and dental professional societies. PMID:20100924

Urinary mercury in people living near point sources of mercury emissions.

PubMed

Barregard, Lars; Horvat, Milena; Mazzolai, Barbara; Sällsten, Gerd; Gibicar, Darija; Fajon, Vesna; Dibona, Sergio; Munthe, John; Wängberg, Ingvar; Haeger Eugensson, Marie

2006-09-01

As part of the European Mercury Emissions from Chlor Alkali Plants (EMECAP) project, we tested the hypothesis that contamination of ambient air with mercury around chlor alkali plants using mercury cells would increase the internal dose of mercury in people living close to the plants. Mercury in urine (U-Hg) was determined in 225 individuals living near a Swedish or an Italian chlor alkali plant, and in 256 age- and sex-matched individuals from two reference areas. Other factors possibly affecting mercury exposure were examined. Emissions and concentrations of total gaseous mercury (TGM) around the plants were measured and modeled. No increase in U-Hg could be demonstrated in the populations living close to the plants. This was the case also when the comparison was restricted to subjects with no dental amalgam and low fish consumption. The emissions of mercury to air doubled the background level, but contributed only about 2 ng/m(3) to long-term averages in the residential areas. The median U-Hg levels in subjects with dental amalgam were 1.2 microg/g creatinine (micro/gC) in Italy and 0.6 microg/gC in Sweden. In individuals without dental amalgam, the medians were 0.9 microg/gC and 0.2 microg/gC, respectively. The number of amalgam fillings, as well as chewing, fish consumption, and female sex were associated with higher U-Hg. The difference between the countries is probably due to higher fish consumption in Italy, demethylated methyl mercury (MeHg) being partly excreted in urine. Post hoc power calculations showed that if the background mercury exposure is low it may be possible to demonstrate an increase in U-Hg of as little as about 10 ng/m(3) as a contribution to ambient mercury from a point source.

Microstructures of Pd-containing dispersants for admixed dental amalgams.

PubMed

Chern Lin, J H; Greener, E H

1991-10-01

Blended Pd-containing dispersants were developed by the utilization of a Ag-Cu eutectic into which Pd was substituted for Ag or Cu in concentrations of up to 20 wt%. Compositions were melted either in argon-filled sealed vycor tubes or in a graphite-linked carbon crucible of an induction furnace with an argon blanket. Ingots of approximately 1.5 cm in diameter were sectioned to 0.2 cm in thickness and polished through standard metallographic polishing procedures. The possible compounds were identified by XRD. The microstructures of the alloys were examined by SEM/EDS. XRD analysis of the alloys revealed the preferential dissolution of Pd in Cu when the Pd concentration was less than or equal to 10 wt%. When the Pd concentration exceeded 20 wt%, Pd was found to be dissolved in both Ag and Pd. No Cu3Pd x-ray diffraction peaks were found for alloys with Pd concentration of up to 20 wt%. SEM/EDS analysis confirmed XRD results; lamellae of Ag and Cu-Pd were found in alloys with Pd concentration less than or equal to 10 wt%.

A systematic review of dental disease management in cancer patients.

PubMed

Hong, Catherine H L; Hu, Shijia; Haverman, Thijs; Stokman, Monique; Napeñas, Joel J; Braber, Jacolien Bos-den; Gerber, Erich; Geuke, Margot; Vardas, Emmanouil; Waltimo, Tuomas; Jensen, Siri Beier; Saunders, Deborah P

2018-01-01

This systematic review aims to update on the prevalence of odontogenic-related infections and the efficacy of dental strategies in preventing dental-related complications in cancer patients since the 2010 systematic review. A literature search was conducted in the databases MEDLINE/PubMed and EMBASE for articles published between 1 January 2009 and 30 June 2016. Each study was assessed by 2 reviewers and the body of evidence for each intervention was assigned an evidence level. After examination of the abstracts and full-text articles, 59 articles satisfied the inclusion criteria. The weighted prevalence of dental infections and pericoronitis during cancer therapy was 5.4 and 5.3%, respectively. The frequency of dental-related infections during intensive chemotherapy after complete, partial, and minimal pre-cancer dental evaluation/treatment protocols ranged from 0 to 4%. Protocols involving third molars extractions had the highest complications (40%). In view of the low prevalence of infections and the potential for complications after third molar extractions, it is suggested that partial dental evaluation/treatment protocols prior to intensive chemotherapy; whereby minor caries (within dentin), asymptomatic third molars or asymptomatic teeth without excessive probing depth (<8 mm), mobility (mobility I or II) or with periapical lesions of <5 mm were observed; is a viable option when there is insufficient time for complete dental evaluation/treatment protocols. The use of chlorhexidine, fluoride mouth rinses as well as composite resin, resin-modified glass ionomer cement (GIC), and amalgam restorations over conventional GIC in post head and neck radiation patients who are compliant fluoride users is recommended.

Dye leakage of four root end filling materials: effects of blood contamination.

PubMed

Torabinejad, M; Higa, R K; McKendry, D J; Pitt Ford, T R

1994-04-01

The purpose of this study was to compare the amount of dye leakage (in the presence versus absence of blood) in root end cavities filled with amalgam, Super EBA, IRM, and a mineral trioxide aggregate. After removing the anatomical crowns of 90 extracted human teeth, their roots were instrumented and obturated. Except for their apical 2 mm, the root surfaces were sealed with nail polish. After removal of the apical 2 to 3 mm of each root, a standardized root end cavity was prepared. Five root ends were filled with gutta-percha and no sealer, and another five root ends were filled with sticky wax. These served as positive and negative controls, respectively. The remaining 80 roots were divided into four equal groups and filled with the test materials. For each material, half of the root end cavities were dried prior to placing the filling material. The remaining half were filled after they were contaminated with blood. All 90 roots were then immediately placed in 1% methylene blue dye for 72 h. Finally, the roots were split and linear dye penetration was measured and statistically analyzed (analysis of variance). Presence or absence of blood had no significant effect on the amount of dye leakage. However, the results showed that there was a significant leakage difference between the root end filling materials (p < 0.0001). Mineral trioxide aggregate leaked significantly less than other materials tested with or without blood contamination of the root end cavities.

A dental look at the autistic patient through orofacial pain.

PubMed

Zeidán-Chuliá, Fares; Gursoy, Ulvi K; Könönen, Eija; Gottfried, Carmem

2011-07-01

Abstract Autism is a neurodevelopmental disorder characterized by impaired social interaction and restricted interests, compromised communication skills, and repetitive patterns of behavior. Both social and behavioral problems, which may include hyperactivity and quick frustration, may hinder the detection of other important pathologies such as orofacial pain. This is aggravated by the invasive nature of oral exploration, which may trigger violent and self-injurious responses, such as temper tantrums and/or head banging, which make the work of professionals extremely difficult during diagnoses, follow-up examinations, and dental treatments. In addition, mercury-containing amalgams used to treat dental caries (the most common form of acute orofacial pain) have been associated with higher rates of severe autism in children. The purpose of this review is to describe the current state of the art regarding the co-occurrence of orofacial pain and autism spectrum disorder, and how these conditions may interrelate clinically and neurobiologically.

Prevalence of dental caries in 5-year-old Greek children and the use of dental services: evaluation of socioeconomic, behavioural factors and living conditions.

PubMed

Mantonanaki, Magdalini; Koletsi-Kounari, Haroula; Mamai-Homata, Eleni; Papaioannou, William

2013-04-01

To assess dental caries and use of dental services experience in 5-year-old children attending public kindergartens in Attica, Greece and to examine the influence of certain socioeconomic factors and living conditions as well as dental behaviours and attitudes. In this cross-sectional study, a random and stratified sample of 605 Greek children was examined using decayed, missing, filled tooth surfaces and simplified debris indices. The use of dental services was measured by children's dental visits (any dental visit up to the age of 5 years). Care Index was also calculated. Risk indicators were assessed by a questionnaire. Zero-inflated Poisson and Logistic Regression Analysis were generated to test statistical significant associations. The prevalence of dental caries was 16.5%. Care Index was 32% and dental visits were reported for the 84% of the children. Medium Socio-Economic Level (SEL) was associated with no detectable caries. High SEL was related to decreased decayed, missing, filled teeth values, while female gender and rented houses had the opposite effect. The age of the mother (35-39 years) and the higher SEL were related to higher levels of dental services use. It is suggested that there are differences in the experience of dental caries and use of dental services among preschool children in Attica, which are related to demographic, socioeconomic factors and living conditions. Dental public polices should focus on groups with specific characteristics in order to improve oral health levels of disease-susceptible populations. © 2013 FDI World Dental Federation.

The effect of oxidizing water on metallic restorations in the mouth: in vitro reduction behavior of oxidizing water.

PubMed

Nishida, T

1997-03-01

Mouth-rinsing with oxydized water which contains electrolytically generated chlorine is known to hinder dental plaque formation and growth, but it also accelerates the deterioration of metallic restorations in the mouth. The present work consists of an in vitro study to elucidate the electrochemical reactions involved in the reduction of oxydized water on dental alloys through a systematic investigation of the potentiostatic polarization behavior of dental alloy electrodes. The five dental alloys selected for investigation were gold alloy, gold alloy containing platinum, silver-palladium-gold alloy, conventional amalgam and high copper amalgam. The corrosion potentials of all dental alloy electrodes were shown to be more noble in oxydized water than in 0.1N sodium chloride solution. The potential differences between the corrosion potentials were relatively small in the case of amalgam electrodes. The polarization curves for all of the dental alloy electrodes in oxydized water revealed reduction currents of chlorine, hypochlorous acid, dissolved oxygen and oxonium ion. The reduction of chlorine and hypochlorous acid started at a more noble potential than that of dissolved oxygen. The dental alloys studied, except the amalgams, did not dissolve excessively at the corrosion potentials in oxydized water.

Real time study of amalgam formation and mercury adsorption on thin gold film by total internal reflection ellipsometry

NASA Astrophysics Data System (ADS)

Paulauskas, A.; Selskis, A.; Bukauskas, V.; Vaicikauskas, V.; Ramanavicius, A.; Balevicius, Z.

2018-01-01

Total internal reflection ellipsometry (TIRE) was utilized in its dynamic data acquisition mode to reveal the percentage of mercury present in an amalgam surface layer. In determining the optical constants of the amalgam film, the non-homogeneities of the formed surface layer were taken into account. The composition of the amalgam layer by percentage was determined using the EMA Bruggemann model for the analysis of the TIRE data. Regression results showed that amalgam layer consisted of mercury 16.00 ± 0.43% and gold 84.00 ± 0.43%. This real time TIRE analysis has shown that for these studies method can detect 0.6 ± 0.4% of mercury on a gold surface, proving that this is a suitable optical technique for obtaining real time readouts. The structural analysis of SEM and AFM have shown that the amalgam layer had a dendritic structure, which formation was determined by the weak adhesion of the gold atoms onto its surface.

An audit on technical quality of root fillings performed by undergraduate students.

PubMed

Fong, W; Heidarifar, O; Killough, S; Lappin, M J; El Karim, I A

2018-04-01

To evaluate radiographically the technical quality of root fillings performed by undergraduate dental students and to assess whether students were exposed to an appropriate endodontic case mix during their clinical training. A retrospective audit was undertaken evaluating the clinical records of patients who underwent endodontic procedures during the period from September 2015 to June 2016 in the Dental School at Queen's University Belfast, UK. Two final-year dental students were trained and calibrated to evaluate postoperative intra-oral periapical radiographs of completed root canal treatments using specific assessment criteria. Data were presented as frequencies, percentage and mean ± standard deviation (SD). Comparisons of treatment outcomes between groups (posterior and anterior teeth) were calculated using Fisher's exact test, and the level of significance was set at P < 0.05. Intra- and interexaminer reproducibility was assessed by Kappa statistics. A total of 222 teeth and 381 canals were assessed, and of those, 253 (66%) of the root fillings were found to be acceptable in all the assessment parameters, namely taper, length and lateral adaptation of the root filling. Subanalysis of individual root filling parameters revealed that 372 canals (97%) exhibited good taper, and 275 canals (72%) were considered to be of an appropriate length, with 89 canals (23%) found to be underfilled and 17 canals (5%) overfilled. Overall 346 (91%) of canals had good lateral condensation. Students treated both single and multirooted teeth, and there was no significant association between tooth type and the quality of root filling provided (P > 0.05). In the majority of the teeth treated by undergraduate students at Queen's University Belfast, the technical quality of the root filling was acceptable and students were exposed to an appropriate case mix for endodontic training. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Fabrication, characterisation and voltammetric studies of gold amalgam nanoparticle modified electrodes.

PubMed

Welch, Christine M; Nekrassova, Olga; Dai, Xuan; Hyde, Michael E; Compton, Richard G

2004-09-20

The tabrication, characterisation, and electroanalytical application of gold and gold amalgam nanoparticles on glassy carbon electrodes is examined. Once the deposition parameters for gold nanoparticle electrodes were optimised, the analytical utility of the electrodes was examined in CrIII electroanalysis. It was found that gold nanoparticle modified (Au-NM) electrodes possess higher sensitivity than gold macroelectrodes. In addition, gold amalgam nanoparticle modified (AuHg-NM) electrodes were fabricated and characterised. The response of those electrodes was recorded in the presence of important environmental analytes (heavy metal cations). It was found AuHg-NM electrodes demonstrate a unique voltammetric behaviour and can be applied for electroanalysis when enhanced sensitivity is crucial.

The amalgamation stage of fusion reactions

NASA Astrophysics Data System (ADS)

Mouze, Genevieve

2005-04-01

There is no need of a repulsive potential in the amalgamation stage for explaining the small fusion cross sections. The repulsive potential proposed by A. Adamian et al.(1) can advantageously be replaced by the affinity of the reaction of re-dissociation of the compound nucleus into its entrance-channel configuration. This reaction, which occurs after the penetration of the Coulomb barrier, is an equilibrium between dual and compact form of the compound nucleus, and the energy Q released in the dissociation is equal to the energy required for amalgamating. The total energy of the confined system being equal to the height B of the Coulomb barrier, the intrinsic excitation energy of the compact nucleus is equal to (B - Q). In the reaction 82Se+ 138Ba (2), the dissociation of 220Th releases 180.524 MeV, and B= 196.08 MeV. With an intrinsic excitation energy of 15.56 MeV, the confined compact 220Th has enough energy for emitting two neutrons ( S(2n) = 13.85 MeV). Thus the favored xn channel of fusion reactions can be precisely predicted. This new, mass-data-based model of fusion is completely parameter-free. 1 G.G. Adamian et al., PRC 69 (2004) 044601. 2 K. Satou et al. PRC C 65(2002) 054602.

Rural and remote dental services shortages: filling the gaps through geo-spatial analysis evidence-based targeting.

PubMed

Shiika, Yulia; Kruger, Estie; Tennant, Marc

Australia has a significant mal-distribution of its limited dental workforce. Outside the major capital cities, the distribution of accessible dental care is at best patchy. This study applied geo-spatial analysis technology to locate gaps in dental service accessibility for rural and remote dwelling Australians, in order to test the hypothesis that there are a few key location points in Australia where further dental services could make a significant contribution to ameliorating the immediate shortage crisis. A total of 2,086 dental practices were located in country areas, covering a combined catchment area of 1.84 million square kilometers, based on 50 km catchment zones around each clinic. Geo-spatial analysis technology was used to identify gaps in the accessibility of dental services for rural and remote dwelling Australians. An extraction of data was obtained to analyse the integrated geographically-aligned database. Results: Resolution of the lack of dental practices for 74 townships (of greater than 500 residents) across Australia could potentially address access for 104,000 people. An examination of the socio-economic mix found that the majority of the dental practices (84%) are located in areas classified as less disadvantaged. Output from the study provided a cohesive national map that has identified locations that could have health improvement via the targeting of dental services to that location. The study identified potential location sites for dental clinics, to address the current inequity in accessing dental services in rural and remote Australia.

Thunder Bay Regional Hospital: an amalgamation.

PubMed

Levac, G

1996-01-01

Two acute care hospitals in Thunder Bay recently amalgamated into a single hospital. Acute care delivery in the region promises to be more efficient and less expensive, and the process has resulted in a hospital better able to absorb the 18 percent provincial funding cut announced last fall. This is an important step in developing a truly efficient and effective continuum of care in Thunder Bay, and an example of successfully meeting the challenges of delivering quality service on a tighter budget.

Influence of dental materials on cells of the equine periodontium.

PubMed

Ringeisen, H; Pöschke, A; Krähling, B; Schröck, C; Stoll, M; Vogelsberg, J; Failing, K; Staszyk, C

2018-05-01

Therapy for equine periodontal disease can include filling of the periodontal pockets and widened interproximal spaces. Recommended dental materials are generally adopted from human dentistry. To evaluate the biocompatibility of dental materials for equine periodontal fillings in vitro. In vitro experiments. Four different dental materials (PeriCare ® , Provicol ® , Calxyl ® and Honigum) were tested on equine periodontal fibroblasts. Possible cytotoxic effects were assessed microscopically and by MTT assay, and the expression of inflammatory marker genes was measured by qRT-PCR. PeriCare ® and Provicol ® had no effects on the cells, whereas Honigum and Calxyl ® were associated with severe cytotoxic effects. The results of this in vitro study need to be confirmed by clinical studies. Before adapting dental materials from human dentistry, it is crucial to initially test them in a specific equine model. © 2017 EVJ Ltd.

Dental data of the Athens 2004 Olympic and Paralympic Games.

PubMed

Vougiouklakis, G; Tzoutzas, J; Farmakis, E-T; Farmakis, E-E; Antoniadou, M; Mitsea, A

2008-11-01

The Athens University, School of Dentistry, accepted the challenge to organize the Dental Health Services in the Athens 2004 Olympic and Paralympic Games in order to provide the best quality of oral health services to the athletes, coaches, escort members and Olympic Village personnel. Data from the whole activity protocol of the Athens 2004 Games Dental Health Services - the reception, admission and treatment protocols, the facilities and the infrastructure, the number of cases treated per specialty and the experience gained - were recorded. During the Olympic Games, there were more than 1400 dental cases in more than 650 patients, elite athletes, escort members, coaches and staff of the Olympic Village. Among them 313 fillings, 100 root canal therapies, 57 mouthguards and 9 dental trauma cases were treated. During the Paralympic Games, there were more than 240 dental cases in more than 220 patients. Among them 73 fillings, 12 root canal therapies, 21 extractions and 3 dental trauma cases were treated. In such events, highly trained dentists are needed and if possible, specialized in operative dentistry or endodontics. The role of team dentist seems to be of great importance.

Determinants of dental health status and dental health behavior among Sana'a University students, Yemen.

PubMed

Halboub, Esam; Dhaifullah, Esam; Yasin, Rasha

2013-11-01

To evaluate the dental health status and toothbrushing behavior among Sana'a University students, and to explore any associations with different factors. In this cross-sectional study, the dental health of 360 students from the dental, medical, and literature faculties (120 each) at Sana'a University were examined using the Decayed, Missing, and Filled Teeth (DMFT) index. Data regarding study field, grade, toothbrushing behavior, parents' education, and smoking and khat chewing habits were recorded. Nearly 76% of students (n = 273) reported regularly brushing their teeth. Excluding fathers' education levels and khat chewing, other factors (faculty, grade, sex, mothers' education, and smoking) were significant independent predictors for this behavior. The overall mean DMFT score (± standard deviation) was 4.13 ± 3.1, and was found to be adversely influenced by smoking, which explained only 1.1% of the variance. Toothbrushing, sex, and smoking were significant independent predictors for the decay score, and explained 10.6% of its variance. Khat chewing was found to be adversely associated with the missing score, with an influence of only 2.9%. The filling score was found to be positively associated with toothbrushing and study grade, which together had an influence of 10%. The dental health and toothbrushing behaviors of Sana'a University students are unsatisfactory, and influenced unequally by different factors. © 2013 Wiley Publishing Asia Pty Ltd.

Pricing and competition in the private dental market in Finland.

PubMed

Widström, E; Väisänen, A; Mikkola, H

2011-06-01

To investigate how the prices were set in private dental care, which factors determined prices and whether the recent National Dental Care Reform had increased competition in the dental care market in Finland. A questionnaire to all full time private dentists (n = 1,121) in the ten largest cities. Characteristics of the practice, prices charged, price setting, perceived competition and expectations for the practices were requested. The response rate was 59.6%. Correlation analysis (Pearson's) was used to study relationships between the prices of different treatment items. Linear regression analysis was used to study determinants of the price of a one surface filling. Most dentists' fee schedules were based on the price of a one surface filling and updated annually. Changes in practice costs calculated by the dentists' professional association and information on average prices charged on dental treatments in the country influenced pricing. High price levels were associated with specialisation, working in a group practice, working close to many other practices or in a town with a dental school. Less than half of the respondents had faced competition in dental services and price competition was insignificant. Price setting followed traditional patterns and private markets in dental services were not found to be very competitive.

The impact of the global budget system on dynamics of dental manpower and utilization of dental services

PubMed Central

Huang, Laura Yueh-Guey; Huang, Boyen

2016-01-01

Background: This study aimed to investigate dentists’ supply and practice patterns following the implementation of the global budget system in Taiwan. Materials and Methods: Data of reimbursement claims, municipal socioeconomic status and dental manpower were collected from the National Health Insurance administration, the Ministry of Internal Affair, and the Ministry of Health and Welfare, respectively. A multivariate linear regression method was used for data analysis. Results: A municipality that reported a higher percentage of tertiary educated population (t = 3.718, P < 0.001), a higher per capita income (t = 6.172, P < 0.001), a higher population density (t = 6.172, P < 0.001), or a lower percentage of elderly population (t = −2.506, P = 0.014) was more likely to have a higher number of dentists per 100,000 population. A municipality that reported a higher Herfindahl-Hirschman Index (HHI) value (t = 2.880, P = 0.005) was more likely to show a higher move-out rate among dentists. The rate was lower after the implementation of the global budget system (t = −2.436, P = 0.018). A municipality that had a higher percentage of elderly population (t = 3.628, P < 0.001), a lower percentage of young population (t = −2.138, P = 0.035), or a higher rate of population growth (t = 4.412, P < 0.001) was more likely to display a higher move-in rate among dentists. The percentage of amalgam restorations in total claims reduced from 19.82% to 17.94%, while the percentage of tooth-colored material restorations increased from 25.46% to 28.79%. Conclusion: This study has demonstrated a stabilizing effect of the global budget system on dynamics of dental manpower in Taiwan. A relationship between HHI and dentists’ move-out rate has been found. The relationship between municipal socioeconomic status and the density of dentists has also been confirmed. In addition, reduced utilization of amalgam restorations was accompanied by increased utilization of tooth

The impact of the global budget system on dynamics of dental manpower and utilization of dental services.

PubMed

Huang, Laura Yueh-Guey; Huang, Boyen

2016-01-01

This study aimed to investigate dentists' supply and practice patterns following the implementation of the global budget system in Taiwan. Data of reimbursement claims, municipal socioeconomic status and dental manpower were collected from the National Health Insurance administration, the Ministry of Internal Affair, and the Ministry of Health and Welfare, respectively. A multivariate linear regression method was used for data analysis. A municipality that reported a higher percentage of tertiary educated population (t = 3.718, P < 0.001), a higher per capita income (t = 6.172, P < 0.001), a higher population density (t = 6.172, P < 0.001), or a lower percentage of elderly population (t = -2.506, P = 0.014) was more likely to have a higher number of dentists per 100,000 population. A municipality that reported a higher Herfindahl-Hirschman Index (HHI) value (t = 2.880, P = 0.005) was more likely to show a higher move-out rate among dentists. The rate was lower after the implementation of the global budget system (t = -2.436, P = 0.018). A municipality that had a higher percentage of elderly population (t = 3.628, P < 0.001), a lower percentage of young population (t = -2.138, P = 0.035), or a higher rate of population growth (t = 4.412, P < 0.001) was more likely to display a higher move-in rate among dentists. The percentage of amalgam restorations in total claims reduced from 19.82% to 17.94%, while the percentage of tooth-colored material restorations increased from 25.46% to 28.79%. This study has demonstrated a stabilizing effect of the global budget system on dynamics of dental manpower in Taiwan. A relationship between HHI and dentists' move-out rate has been found. The relationship between municipal socioeconomic status and the density of dentists has also been confirmed. In addition, reduced utilization of amalgam restorations was accompanied by increased utilization of tooth-colored material restorations. Further investigations are indicated.

Teaching the placement of posterior resin-based composite restorations in Spanish dental schools

PubMed Central

Lynch, Christopher; McConnell, Robert; Wilson, Nairn

2012-01-01

Objectives: In an area of esthetic dentistry such as posterior composites, in which new materials and techniques are being devolved continuously, it is important to confirm that dental students have a clear understanding of the basic principles of clinical application of this knowledge. Considering that the preparation of dental graduates in Spain may be of interest to competent dental authorities and employers with whom they can work worldwide, this study investigated the teaching of posterior composite restorations in Spanish dental schools. Study design: In late 2009⁄ early 2010, a questionnaire seeking information on the teaching of posterior composites was emailed to the professor responsible for teaching operative dentistry in each of the fifteen dental schools having complete undergraduate dental degree programs in Spain. Results: The response rate was 100%. Most investigated topics did not show noteworthy differences depending on whether the schools were public or private. Variations were found among Spanish dental schools in both the amount and content of the teaching programs concerning posterior composite restorations. Differences were recorded in the teaching of cavity design, contraindications to composite placement, indications for liners and bases, matrix and wedging techniques, composite and bonding systems, light curing and finishing procedures for composite restorations. More consistency was observed in teaching methods of moisture-control, indirect composites and amalgam bonding. Conclusions: As recommended in previously surveyed countries, efforts must be made to promote harmonization of dental curricula to make it easier for graduates to work elsewhere, and to ensure they meet the needs of their patients on entering independent practice. Key words:Aesthetic dentistry, composite restoration, dental education, teaching program, undergraduate dental student. PMID:22322491

Taguchi optimization: Case study of gold recovery from amalgamation tailing by using froth flotation method

NASA Astrophysics Data System (ADS)

Sudibyo, Aji, B. B.; Sumardi, S.; Mufakir, F. R.; Junaidi, A.; Nurjaman, F.; Karna, Aziza, Aulia

2017-01-01

Gold amalgamation process was widely used to treat gold ore. This process produces the tailing or amalgamation solid waste, which still contains gold at 8-9 ppm. Froth flotation is one of the promising methods to beneficiate gold from this tailing. However, this process requires optimal conditions which depends on the type of raw material. In this study, Taguchi method was used to optimize the optimum conditions of the froth flotation process. The Taguchi optimization shows that the gold recovery was strongly influenced by the particle size which is the best particle size at 150 mesh followed by the Potassium amyl xanthate concentration, pH and pine oil concentration at 1133.98, 4535.92 and 68.04 gr/ton amalgamation tailing, respectively.

Teaching the placement of posterior resin-based composite restorations in Spanish dental schools.

PubMed

Castillo-de Oyagüe, Raquel; Lynch, Christopher; McConnell, Robert; Wilson, Nairn

2012-07-01

In an area of esthetic dentistry such as posterior composites, in which new materials and techniques are being devolved continuously, it is important to confirm that dental students have a clear understanding of the basic principles of clinical application of this knowledge. Considering that the preparation of dental graduates in Spain may be of interest to competent dental authorities and employers with whom they can work worldwide, this study investigated the teaching of posterior composite restorations in Spanish dental schools. In late 2009⁄ early 2010, a questionnaire seeking information on the teaching of posterior composites was emailed to the professor responsible for teaching operative dentistry in each of the fifteen dental schools having complete undergraduate dental degree programmes in Spain. The response rate was 100%. Most investigated topics did not show noteworthy differences depending on whether the schools were public or private. Variations were found among Spanish dental schools in both the amount and content of the teaching programmes concerning posterior composite restorations. Differences were recorded in the teaching of cavity design, contraindications to composite placement, indications for liners and bases, matrix and wedging techniques, composite and bonding systems, light curing and finishing procedures for composite restorations. More consistency was observed in teaching methods of moisture-control, indirect composites and amalgam bonding. As recommended in previous surveyed countries, efforts must be made to promote harmonization of dental curricula to make it easier for graduates to work elsewhere, and to ensure they meet the needs of their patients on entering independent practice.

Artifacts resembling budding bacteria produced in placer-gold amalgams by nitric acid leaching

USGS Publications Warehouse

Watterson, J.R.

1994-01-01

Microscopic filiform morphologies in gold which are indistinguishable from forms originally interpreted as bacterial in origin were produced in the laboratory by treating amalgams made from natural and artificial gold with hot nitric acid. Textures ranging from cobblestone to deeply crenulated to nodular filiform were produced in the laboratory from all tested natural and artificial gold amalgams; analogous textures widespread in Alaskan placer gold may have a similar inorganic origin. These results indicate that morphology alone cannot be considered adequate evidence of microbial involvement in gold formation.

Does dental health of 6-year-olds reflect the reform of the Israeli dental care system?

PubMed

Natapov, Lena; Sasson, Avi; Zusman, Shlomo P

2016-01-01

The National health insurance law enacted in 1995 did not include dental care in its basket of services. Dental care for children was first included in 2010, initially up till 8 years of age. The eligibility age rose to 12 years in 2013. The dental survey of 6 year-olds in 2007 found that the average of decayed, missing and filled teeth index (dmft) was 3.31 and 35 % of children were caries free. The current cross sectional survey of dental health for 6 year-olds was conducted as a comparison to the pre-reform status. Twenty-three local authorities were randomly selected nationwide. Two Grade 1 classes were randomly chosen in each. The city of Jerusalem was also included in the survey because of its size. The children were examined according to the WHO Oral Health Survey Methods 4th ed protocol. The dental caries index for deciduous teeth (dmft: decayed, missing, filled teeth) was calculated. One thousand two hundred ten children were examined. 61.7 % of the children suffered from dental decay and only 38.3 % were caries free. The mean dmft was 2.56; d = 1.41 (teeth with untreated caries), f = 1.15 (teeth damaged by decay and restored), virtually none were missing due to caries. Dental caries prevalence was rather consistent, an average of over 2 teeth affected per child. Although there is no major change in comparison to former surveys, there is more treated than untreated disease. In the present survey the f component is higher than in the past, especially in the Jewish sector where it is the main component. It is still lower in the Arab sector. Although the level of dental disease remained rather constant, an increase in the treatment component was observed. In order to reduce caries prevalence, preventive measures such as school dental services and drinking water fluoridation should be extended and continued. Primary preventive dental services should be established for children from birth, with an emphasis on primary health care and educational

Is treatment under general anaesthesia associated with dental neglect and dental disability among caries active preschool children?

PubMed

Kvist, T; Zedrén-Sunemo, J; Graca, E; Dahllöf, G

2014-10-01

To study if treatment under general anaesthesia (GA) is associated with dental neglect or dental disability. This was a retrospective study. Dental records of all children in the age 0-6 years who underwent GA at a specialist paediatric dentistry clinic during 2006-2011 were studied with regard to decayed-missed-filled teeth, traumatic injuries, emergency visits, behaviour management problems and the history of attendance. The final sample consisted of 134 children. Matched controls were selected among recall patients who had not received treatment under GA. Fishers exact test or Pearson Chi-square test analysed response distribution and comparisons between groups, and for multivariate analyses, logistic regression was used. The results show that children treated under GA had significantly higher caries prevalence, apical periodontitis and infections due to pulpal necrosis. Dental neglect as well as dental disability was significantly more prevalent in the GA group compared to the control group. In a multivariate analysis with dental neglect as independent factor, dental disability was the only significant factor (p = 0.006). Children treated under general anaesthesia were significantly more often diagnosed with both dental neglect and dental disability. Dental disability was the only factor significantly related to dental neglect. There is a need for improved documentation in the dental records to better identify dental neglect and dental disability, and also a continued training of dentists regarding child protection.

Artifacts resembling budding bacteria produced in placer-gold amalgams by nitric acid leaching

USGS Publications Warehouse

Watterson, J.R.

1994-01-01

Microscopic filiform morphologies in gold which are indistinguishable from forms originally interpreted as bacterial in origin were produced in the laboratory by treating amalgams made from natural and artificial gold with hot nitric acid. Textures ranging from cobblestone to deeply crenulated to nodular filiform were produced in the laboratory from all tested natural and artificial gold amalgams; analogous textures widespread in Alaskan placer gold may have a similar inorganic origin. These results indicate that morphology alone cannot be considered adequate evidence of microbial involvement in gold formation. -Author

Dental care of autistic children within the non-specialized Public Dental Service.

PubMed

Fahlvik-Planefeldt, C; Herrström, P

2001-01-01

Children with an autistic disorder may need more dental care and may also be more difficult to treat than healthy children. This study compared oral health in autistic and healthy children. Also explored was the dental management of autistic children within the non-specialized Public Dental Service. The study was designed as a case-control study with all cases of autistic disorders aged 3-19 years identified within a primary care area in southwest Sweden. One dentist did a clinical investigation of cases and one control per case. The patients, or their parents, answered a questionnaire. 28 patients were identified and 20 (71%) agreed to participate in the study. Cases and controls had a similar prevalence of fillings, caries, gingivitis and degree of oral hygiene. However, the need of orthodontic treatment seemed to be greater among the autistic children. According to a standardised assessment, autistic children were less able to cooperate in the dental treatment. Approximately 30% of the cases had occasionally been subjected to specialized dental care. The results of this study indicate that the care provided to autistic children within the non-specialized Public Dental Service is satisfactory, provided that there is access to a paediatric dentist when necessary.

Sugar consumption and dental caries experience in Kenya.

PubMed

Macigo, Francis Githua; James, Regina Mutave; Ogunbodede, Eyitope; Gathece, Loice Warware

2016-06-01

There have been claims that dental caries experience and prevalence in Kenya has been increasing as a result of increased sugar consumption. A review of the literature in 1986 failed to link dental caries experience with an increase in gross national sugar consumption. Subsequently, a number of studies were conducted, necessitating further review to examine trends in dental caries experience and to relate this to changes in per capita sugar consumption. Studies conducted since 1980 for children 3-15 years of age were examined. Dental caries prevalence and experience for 3-5 years' (deciduous teeth) and 12 years' (permanent teeth) age groups were analysed. Calculation of per capita sugar consumption was performed using gross national annual sugar consumption for 1969-2009 national population census years. There was a gradual increase in per capita sugar consumption, from 35.5 g/day in 1969 to 60.8 g/day in 2009. Dental caries experience in deciduous teeth for children 3-5 years of age increased from a decayed, missing and filled teeth/decayed and filled teeth (dmft/dft) index of 1.5 in the 1980s to 2.95 in the 2000s. At 12 years of age, caries experience for permanent teeth increased from a DMFT of 0.2 to a DMFT of 0.92 over the same period. Dental caries prevalence for both deciduous and permanent teeth also increased with time. These observations suggest that dental caries prevalence and experience increased with time, in parallel to an increase in per capita sugar consumption. However, a clearer understanding can be derived from longitudinal studies, based on actual household age-specific sugar consumption and dental caries incidence. © 2016 FDI World Dental Federation.

Sedimentology and reservoir heterogeneity of a valley-fill deposit-A field guide to the Dakota Sandstone of the San Rafael Swell, Utah

USGS Publications Warehouse

Kirschbaum, Mark A.; Schenk, Christopher J.

2010-01-01

Valley-fill deposits form a significant class of hydrocarbon reservoirs in many basins of the world. Maximizing recovery of fluids from these reservoirs requires an understanding of the scales of fluid-flow heterogeneity present within the valley-fill system. The Upper Cretaceous Dakota Sandstone in the San Rafael Swell, Utah contains well exposed, relatively accessible outcrops that allow a unique view of the external geometry and internal complexity of a set of rocks interpreted to be deposits of an incised valley fill. These units can be traced on outcrop for tens of miles, and individual sandstone bodies are exposed in three dimensions because of modern erosion in side canyons in a semiarid setting and by exhumation of the overlying, easily erodible Mancos Shale. The Dakota consists of two major units: (1) a lower amalgamated sandstone facies dominated by large-scale cross stratification with several individual sandstone bodies ranging in thickness from 8 to 28 feet, ranging in width from 115 to 150 feet, and having lengths as much as 5,000 feet, and (2) an upper facies composed of numerous mud-encased lenticular sandstones, dominated by ripple-scale lamination, in bedsets ranging in thickness from 5 to 12 feet. The lower facies is interpreted to be fluvial, probably of mainly braided stream origin that exhibits multiple incisions amalgamated into a complex sandstone body. The upper facies has lower energy, probably anastomosed channels encased within alluvial and coastal-plain floodplain sediments. The Dakota valley-fill complex has multiple scales of heterogeneity that could affect fluid flow in similar oil and gas subsurface reservoirs. The largest scale heterogeneity is at the formation level, where the valley-fill complex is sealed within overlying and underlying units. Within the valley-fill complex, there are heterogeneities between individual sandstone bodies, and at the smallest scale, internal heterogeneities within the bodies themselves. These

Dental optical tomography with upconversion nanoparticles—a feasibility study

PubMed Central

Long, Feixiao; Intes, Xavier

2017-01-01

Abstract. Upconversion nanoparticles (UCNPs) have the unique ability to emit multiple colors upon excitation by near-infrared (NIR) light. Herein, we investigate the potential use of UCNPs as contrast agents for dental optical tomography, with a focus on monitoring the status of fillings after dental restoration. The potential of performing tomographic imaging using UCNP emission of visible or NIR light is established. This in silico and ex vivo study paves the way toward employing UCNPs as theranostic agents for dental applications. PMID:28586852

Dental optical tomography with upconversion nanoparticles—a feasibility study

NASA Astrophysics Data System (ADS)

Long, Feixiao; Intes, Xavier

2017-06-01

Upconversion nanoparticles (UCNPs) have the unique ability to emit multiple colors upon excitation by near-infrared (NIR) light. Herein, we investigate the potential use of UCNPs as contrast agents for dental optical tomography, with a focus on monitoring the status of fillings after dental restoration. The potential of performing tomographic imaging using UCNP emission of visible or NIR light is established. This in silico and ex vivo study paves the way toward employing UCNPs as theranostic agents for dental applications.

Dental optical tomography with upconversion nanoparticles-a feasibility study.

PubMed

Long, Feixiao; Intes, Xavier

2017-06-01

Upconversion nanoparticles (UCNPs) have the unique ability to emit multiple colors upon excitation by near-infrared (NIR) light. Herein, we investigate the potential use of UCNPs as contrast agents for dental optical tomography, with a focus on monitoring the status of fillings after dental restoration. The potential of performing tomographic imaging using UCNP emission of visible or NIR light is established. This in silico and ex vivo study paves the way toward employing UCNPs as theranostic agents for dental applications.

Prevalence and correlates of dental caries in an elderly population in northeast China.

PubMed

Liu, Lu; Zhang, Ying; Wu, Wei; Cheng, Min; Li, Yan; Cheng, Ruibo

2013-01-01

The present study aimed to investigate the prevalence and correlates of dental caries in elderly population in northeast China. A community-based, cross-sectional study among 2376 elderly subjects (age: 65-74 years) from nine urban areas and nine rural areas in three provinces of northeast China was conducted using multistage stratified random sampling per the World Health Organization oral health survey methodology. Decayed-missing-filled teeth (DMFT) and decayed-filled teeth (DFT) indices were used to evaluate the prevalence of dental caries. Face-to-face questionnaire survey on oral health was performed in a randomly selected subset (n = 1197). T test and chi square test were employed to compare groups for continuous and categorical variables, respectively. Multivariate logistic regression was used to estimate odds ratios (ORs) and corresponding confidence intervals (CIs). 67.5% of elderly subjects reported dental caries (average DFT = 2.68±3.40), and the prevalence was higher in urban areas (P<0.01). Missing teeth accounted for 80.72% of DMFT, and filled teeth due to caries accounted for 2.08% with a rate higher in urban areas (P<0.01). Logistic regression analysis indicated significant association among elderly population in urban areas (OR 1.713; 95% CI 1.337-2.195), smoking (OR 1.779; 95% CI 1.384-2.288), and individuals without dental insurance (OR 2.050; 95% CI 1.120-3.754) with dental caries. The prevalence of dental caries in the elderly population in northeast China is high. The elderly from urban areas who smoke and who do not have a dental insurance are at a higher risk to develop dental caries.

Dental equipment test during zero-gravity flight

NASA Technical Reports Server (NTRS)

Young, John; Gosbee, John; Billica, Roger

1991-01-01

The overall objectives of this program were to establish performance criteria and develop prototype equipment for use in the Health Maintenance Facility (HMF) in meeting the needs of dental emergencies during space missions. The primary efforts during this flight test were to test patient-operator relationships, patent (manikin) restraint and positioning, task lighting systems, use and operation of dental rotary instruments, suction and particle containment system, dental hand instrument delivery and control procedures, and the use of dental treatment materials. The initial efforts during the flight focused on verification of the efficiency of the particle containment system. An absorptive barrier was also tested in lieu of the suction collector. To test the instrument delivery system, teeth in the manikin were prepared with the dental drill to receive restorations, some with temporary filling materials and another with definitive filling material (composite resin). The best particle containment came from the combination use of the laminar-air/suction collector in concert with immediate area suction from a surgical high-volume suction tip. Lighting in the treatment area was provided by a flexible fiberoptic probe. This system is quite effective for small areas, but for general tasks ambient illumination is required. The instrument containment system (elastic cord network) was extremely effective and easy to use. The most serious problem with instrument delivey and actual treatment was lack of time during the microgravity sequences. The restorative materials handled and finished well.

Composition, Production Rate and Management of Dental Solid Waste in 2017 in Birjand, Iran.

PubMed

Momeni, Habibe; Tabatabaei Fard, Seyyedeh Fatemeh; Arefinejad, Aliye; Afzali, Afsane; Talebi, Farkhonde; Rahmanpour Salmani, Elham

2018-01-01

The presence of toxic and pathogenic agents in the dental waste products has made it to be classified as "hazardous waste." To assess dental waste production rate and composition and approaches used to manage these waste products in 2017 in Birjand, Iran. 48 dental clinics were evaluated in two months of 2017. Sampling was performed from each clinic 3 times a week. Samples were manually divided into 5 categories of chemical-pharmaceutical, infectious, semi-household, sharp and cutting materials, and toxic waste products, and weighed. A checklist containing 25 questions was used to evaluate the aspects of waste management in dental clinics. The total amount of waste products generated in dental clinics was 7848.02 kg/ year in which semi-household waste had the highest quantity (4263.411 kg/year) and toxic waste had the lowest quantity (9.275 kg/year). Components with the highest amounts in dentistry waste products were nylon gloves (16.7%), paper and cardboard (13.4%), latex gloves (10.8%), and pharmaceuticals (10.2%). Waste separation was restricted to sharp and cutting waste. More than half (57%) of dental units were equipped with amalgam filter. Fixing solutions were directly discharged to sewage in 48.6% of clinics. There was no program to reduce waste generation in 54% of the clinics. Autoclave was the main tool for sterilizing dental instruments. This study showed a remarkable share of recyclable materials in the composition of dental waste and lack of special approach to manage waste in dental clinics. It is necessary to plan for minimizing generation of, separating, and recycling waste at source.

Direct composite fillings: an optical coherence tomography and microCT investigation

NASA Astrophysics Data System (ADS)

Negrutiu, Meda L.; Sinescu, Cosmin; Borlea, Mugurel V.; Manescu, Adrian; Duma, Virgil F.; Rominu, Mihai; Podoleanu, Adrian G.

2015-03-01

The treatment of carious lesions requires removal of affected dental tissue thus creating cavities that are to be filled with dedicated materials. There are several methods known which are used to assess the quality of direct dental restorations, but most of them are invasive. Optical tomographic techniques are of particular importance in the medical imaging field, because these techniques can provide non-invasive diagnostic images. Using an en-face version of OCT, we have recently demonstrated real time thorough evaluation of quality of dental fillings. The major aim of this study was to analyses the optical performance of adhesives modified with zirconia particles in different concentrations in order to improve the contrast of OCT imaging of the interface between the tooth structure, adhesive and composite resin. The OCT investigations were validated by micro CT using synchrotron radiation. The OCT Swept Source is a valuable investigation tool for the clinical evaluation of class II direct composite restorations. The unmodified adhesive layer shows poor contrast on regular OCT investigations. Adding zirconia particles to the adhesive layer provides a better scattering which allows a better characterization and quantification of direct restorations.

Modelling the Longevity of Dental Restorations by means of a CBR System

PubMed Central

Aliaga, Ignacio J.; Vera, Vicente; García, Alvaro E.

2015-01-01

The lifespan of dental restorations is limited. Longevity depends on the material used and the different characteristics of the dental piece. However, it is not always the case that the best and longest lasting material is used since patients may prefer different treatments according to how noticeable the material is. Over the last 100 years, the most commonly used material has been silver amalgam, which, while very durable, is somewhat aesthetically displeasing. Our study is based on the collection of data from the charts, notes, and radiographic information of restorative treatments performed by Dr. Vera in 1993, the analysis of the information by computer artificial intelligence to determine the most appropriate restoration, and the monitoring of the evolution of the dental restoration. The data will be treated confidentially according to the Organic Law 15/1999 on 13 December on the Protection of Personal Data. This paper also presents a clustering technique capable of identifying the most significant cases with which to instantiate the case-base. In order to classify the cases, a mixture of experts is used which incorporates a Bayesian network and a multilayer perceptron; the combination of both classifiers is performed with a neural network. PMID:25866792

Hospital admissions for neurological and renal diseases among dentists and dental assistants occupationally exposed to mercury.

PubMed

Thygesen, Lau Caspar; Flachs, Esben Meulengracht; Hanehøj, Kirsten; Kjuus, Helge; Juel, Knud

2011-12-01

For many years an amalgam containing metallic mercury, which has been associated with neurological and renal diseases, has been used in dentistry. In this nationwide study we compared hospital admissions due to neurological and renal diseases among dentists and dental assistants to admissions in controls. This register-based cohort study included all Danish workers employed in dental clinics, general practitioners' clinics or lawyers' offices between 1964 and 2006. We compared dentists with general practitioners and lawyers, and dental assistants with medical secretaries, nurses and legal secretaries. We also compared dentists and dental assistants employed during periods with high occupational mercury exposure with dentists and dental assistants employed during periods with less mercury exposure. We followed all subjects in a nationwide register of hospital admissions. We analysed risk of neurological diseases, Parkinson's disease and renal diseases using a Cox regression model. The cohort consisted of 122,481 workers including 5371 dentists and 33,858 dental assistants. For neurological diseases, no association was observed for dental assistants, while for dentists an increasing risk for periods with less mercury exposure was observed. Among dental assistants, a negative association between employment length and risk of neurological disease was observed. Admissions for renal disease among dental assistants were increased during periods with less mercury exposure compared with controls. For dentists a non-significant increased risk was observed between employment length and renal disease risk. Our nationwide study does not indicate that occupational exposure to mercury increases the risk of hospital admissions for neurological, Parkinson's or renal diseases.

Preparation and properties of calcium-silicate filled resins for dental restoration. Part II: Micro-mechanical behaviour to primed mineral-depleted dentine.

PubMed

Profeta, Andrea Corrado

2014-11-01

Evaluating microtensile bond strength (μTBS) and Knoop micro-hardness (KHN) of resin bonded-dentine interfaces created with two methacrylate-based systems either incorporating Bioglass 45S5 (3-E&RA/BG) or MTA (3-E&RA/WMTA). Solvated resins (50% ethanol/50% co-monomers) were used as primers while their neat counterparts were filled with the two calcium-silicate compounds. Application of neat resin adhesive with no filler served as control (3-E&RA). μTBS, KHN analysis and confocal tandem scanning microscopy (TSM) micropermeability were carried out after 24 h and 10 months of storage in phosphate buffer solution (DPBS). Scanning electron microscopy (SEM) was also performed after debonding. High μTBS values were achieved in all groups after 24 h of DPBS storage. On the contrary, solely the specimens created using 3-E&RA/BG and 3-E&RA/WMTA agents showed no significant reduction in terms of μTBS even after 10 months in DPBS; similarly, they did not restore the average superficial micro-hardness to the level of sound dentine, but maintained unchanged KHN values, and no statistical decrease was found following 10 months of DPBS storage. The only statistically significant changes occurred in the resin-dentine interfaces bonded with 3-E&RA that were subjected to a reduction of both μTBS and KHN values with ageing. In terms of micropermeability, adverse results were obtained with 3-E&RA while 3-E&RA/BG and 3-E&RA/WMTA demonstrated a beneficial effect after prolonged DPBS storage. Calcium-silicate filled composite resins performed better than a current etch-and-rinse adhesive and had a therapeutic/protective effect on the micro-mechanical properties of mineral-depleted resin-dentine interfaces. The incorporation of calcium-silicates into dental restorative and bonding agents can create more biomimetic (life-like) restorations. This will not only enable these materials to mimic the physical characteristics of the tooth structure, but will also stabilize and protect the

Glutathione enzyme and selenoprotein polymorphisms associate with mercury biomarker levels in Michigan dental professionals

PubMed Central

Goodrich, Jaclyn M.; Wang, Yi; Gillespie, Brenda; Werner, Robert; Franzblau, Alfred; Basu, Niladri

2012-01-01

Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione s-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n=515), and total mercury content was measured. Average urine (1.06±1.24 ug/L) and hair mercury levels (0.49±0.63 ug/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5’), or both (SEPP1 3’UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption). PMID:21967774

A model for amalgamation in group decision making

NASA Technical Reports Server (NTRS)

Cutello, Vincenzo; Montero, Javier

1992-01-01

In this paper we present a generalization of the model proposed by Montero, by allowing non-complete fuzzy binary relations for individuals. A degree of unsatisfaction can be defined in this case, suggesting that any democratic aggregation rule should take into account not only ethical conditions or some degree of rationality in the amalgamating procedure, but also a minimum support for the set of alternatives subject to the group analysis.

Reconstruction-Based Digital Dental Occlusion of the Partially Edentulous Dentition.

PubMed

Zhang, Jian; Xia, James J; Li, Jianfu; Zhou, Xiaobo

2017-01-01

Partially edentulous dentition presents a challenging problem for the surgical planning of digital dental occlusion in the field of craniomaxillofacial surgery because of the incorrect maxillomandibular distance caused by missing teeth. We propose an innovative approach called Dental Reconstruction with Symmetrical Teeth (DRST) to achieve accurate dental occlusion for the partially edentulous cases. In this DRST approach, the rigid transformation between two symmetrical teeth existing on the left and right dental model is estimated through probabilistic point registration by matching the two shapes. With the estimated transformation, the partially edentulous space can be virtually filled with the teeth in its symmetrical position. Dental alignment is performed by digital dental occlusion reestablishment algorithm with the reconstructed complete dental model. Satisfactory reconstruction and occlusion results are demonstrated with the synthetic and real partially edentulous models.

Reconstruction-based Digital Dental Occlusion of the Partially Edentulous Dentition

PubMed Central

Zhang, Jian; Xia, James J.; Li, Jianfu; Zhou, Xiaobo

2016-01-01

Partially edentulous dentition presents a challenging problem for the surgical planning of digital dental occlusion in the field of craniomaxillofacial surgery because of the incorrect maxillomandibular distance caused by missing teeth. We propose an innovative approach called Dental Reconstruction with Symmetrical Teeth (DRST) to achieve accurate dental occlusion for the partially edentulous cases. In this DRST approach, the rigid transformation between two symmetrical teeth existing on the left and right dental model is estimated through probabilistic point registration by matching the two shapes. With the estimated transformation, the partially edentulous space can be virtually filled with the teeth in its symmetrical position. Dental alignment is performed by digital dental occlusion reestablishment algorithm with the reconstructed complete dental model. Satisfactory reconstruction and occlusion results are demonstrated with the synthetic and real partially edentulous models. PMID:26584502

Prevalence and Correlates of Dental Caries in an Elderly Population in Northeast China

PubMed Central

Liu, Lu; Zhang, Ying; Wu, Wei; Cheng, Min; Li, Yan; Cheng, Ruibo

2013-01-01

Objectives The present study aimed to investigate the prevalence and correlates of dental caries in elderly population in northeast China. Methods A community-based, cross-sectional study among 2376 elderly subjects (age: 65–74 years) from nine urban areas and nine rural areas in three provinces of northeast China was conducted using multistage stratified random sampling per the World Health Organization oral health survey methodology. Decayed-missing-filled teeth (DMFT) and decayed-filled teeth (DFT) indices were used to evaluate the prevalence of dental caries. Face-to-face questionnaire survey on oral health was performed in a randomly selected subset (n = 1197). T test and chi square test were employed to compare groups for continuous and categorical variables, respectively. Multivariate logistic regression was used to estimate odds ratios (ORs) and corresponding confidence intervals (CIs). Results 67.5% of elderly subjects reported dental caries (average DFT = 2.68±3.40), and the prevalence was higher in urban areas (P<0.01). Missing teeth accounted for 80.72% of DMFT, and filled teeth due to caries accounted for 2.08% with a rate higher in urban areas (P<0.01). Logistic regression analysis indicated significant association among elderly population in urban areas (OR 1.713; 95% CI 1.337–2.195), smoking (OR 1.779; 95% CI 1.384–2.288), and individuals without dental insurance (OR 2.050; 95% CI 1.120–3.754) with dental caries. Conclusions The prevalence of dental caries in the elderly population in northeast China is high. The elderly from urban areas who smoke and who do not have a dental insurance are at a higher risk to develop dental caries. PMID:24260129

Mercury poisoning dentistry: high-level indoor air mercury contamination at selected dental sites.

PubMed

Khwaja, Mahmood A; Abbasi, Maryam Shabbir

2014-01-01

Mercury (Hg), also known as quick silver, is an essential constituent of dental amalgam. It is a toxic substance of global concern. Children are more at risk from mercury poisoning which affects their neurological development and brain. In the past, a number of studies at dental sites in many countries have been carried out and reported. The present report briefly describes and discusses our recent investigations carried out at 34 dental sites (teaching institutions, hospitals and private clinics) in Pakistan. It is evident from the data that at many sites the indoor mercury vapor levels exceed far above the permissible limit recommended for safe physical and mental health. At these sites, public in general and the medical, paramedical staff and vulnerable population in particular, are at most serious risk to health resulting from exposure to toxic and hazardous mercury. To minimize such risk, some of the recommendations are, best in-house environmental practices for occupational health and safety, mercury contaminated waste reduction at source, mercury specific legislation and ratification of Minamata convention on mercury by Pakistan and other world governments at the earliest time possible.

[Investigation of status of dental caries in children of primary school in Hangzhou city from 2009 to 2011].

PubMed

Hu, Qi-yong; Liu, Min; Wang, Ren-fei; Li, Xiao-feng; Jing, Chang; Tian, Xiao-hua

2013-04-01

To investigate the status of dental caries in children of primary school in Hangzhou City from 2009 to 2011. The status of dental caries was examined annually from 2009 to 2011, and the caries prevalence, filling rates, mean DMFT/dmft were recorded. SPSS 13.0 software package was used for statistical analysis. From 2009 to 2011, the caries prevalence of deciduous teeth were 49.27%, 48.09% and 48.33%, mean dmft were 2.78, 2.81 and 2.84, filling rates of deciduous teeth were 3.92%, 4.31% and 4.28%, respectively. No significant difference was found in the caries prevalence of temporary teeth, filling rates of temporary teeth, mean dmft. For the permanent teeth, the caries prevalence were 20.24%, 18.48% and 15.85%, mean DMFT were 0.46, 0.41 and 0.33, filling rates were 10.17%, 15.67% and 23.00%, respectively. From 2009 to 2011, the caries prevalence and mean DMFT of permanent teeth was decreased, while the filling rate was increased. In the past three years, the status of dental caries of permanent teeth shows a remarkable improving tendency in children of primary school in Hangzhou City. However, the status of dental caries of deciduous teeth presents no significant improvement.

Evaluation of technical quality and periapical health of root-filled teeth by using cone-beam CT

PubMed Central

Bilge Gülsüm, NUR; Evren, OK; ALTUNSOY, Mustafa; AĞLARCI, Osman Sami; ÇOLAK, Mehmet; GÜNGÖR, Enes

2014-01-01

Objective This study aimed to assess the quality of root fillings, coronal restorations, complications of all root-filled teeth and their association with apical periodontitis (AP) detected by cone-beam computed tomography (CBCT) images from an adult Turkish subpopulation. Material and Methods The sample for this study consisted of 242 patients (aging from 15 to 72 years) with 522 endodontically treated teeth that were assessed for technical quality of the root canal filling and periapical status of the teeth. Additionally, the apical status of each root-filled tooth was assessed according to the gender, dental arch, tooth type and age classification, undetected canals, instrument fracture, root fracture, apical resorption, apical lesion, furcation lesion and type and quality of the coronal structure. Statistical analysis was performed using percentages and chi-square test. Results The success rate of the root canal treatment was of 54.4%. The success rates of adequate and inadequate root canal treatment were not significantly different (p>0.05). Apical periodontitis was found in 228 (45.6%) teeth treated for root canals. Higher prevalence of AP was found in patients aging from 20 to 29 years [64 (27%) teeth] and in anterior (canines and incisors) teeth [97 (41%) teeth]. Conclusions The technical quality of root canal filling performed by dental practitioners in a Turkish subpopulation was consistent with a high prevalence of AP. The probable reasons for this failure are multifactorial, and there may be a need for improved undergraduate education and postgraduate courses to improve the clinical skills of dental practitioners in endodontics. PMID:25591019

Dual-energy-based metal segmentation for metal artifact reduction in dental computed tomography.

PubMed

Hegazy, Mohamed A A; Eldib, Mohamed Elsayed; Hernandez, Daniel; Cho, Myung Hye; Cho, Min Hyoung; Lee, Soo Yeol

2018-02-01

In a dental CT scan, the presence of dental fillings or dental implants generates severe metal artifacts that often compromise readability of the CT images. Many metal artifact reduction (MAR) techniques have been introduced, but dental CT scans still suffer from severe metal artifacts particularly when multiple dental fillings or implants exist around the region of interest. The high attenuation coefficient of teeth often causes erroneous metal segmentation, compromising the MAR performance. We propose a metal segmentation method for a dental CT that is based on dual-energy imaging with a narrow energy gap. Unlike a conventional dual-energy CT, we acquire two projection data sets at two close tube voltages (80 and 90 kV p ), and then, we compute the difference image between the two projection images with an optimized weighting factor so as to maximize the contrast of the metal regions. We reconstruct CT images from the weighted difference image to identify the metal region with global thresholding. We forward project the identified metal region to designate metal trace on the projection image. We substitute the pixel values on the metal trace with the ones computed by the region filling method. The region filling in the metal trace removes high-intensity data made by the metallic objects from the projection image. We reconstruct final CT images from the region-filled projection image with the fusion-based approach. We have done imaging experiments on a dental phantom and a human skull phantom using a lab-built micro-CT and a commercial dental CT system. We have corrected the projection images of a dental phantom and a human skull phantom using the single-energy and dual-energy-based metal segmentation methods. The single-energy-based method often failed in correcting the metal artifacts on the slices on which tooth enamel exists. The dual-energy-based method showed better MAR performances in all cases regardless of the presence of tooth enamel on the slice of

Radiographic technical quality of root canal treatment performed ex vivo by dental students at Valencia University Medical and Dental School, Spain

PubMed Central

Faus-Matoses, Vicente; Alegre-Domingo, Teresa; Faus-Llácer, Vicente J.

2014-01-01

Objectives: To evaluate radiographically the quality of root canal fillings and compare manual and rotary preparation performed on extracted teeth by undergraduate dental students. Study Design: A total of 561 premolars and molars extracted teeth were prepared using nickel-titanium rotary files or manual instrumentation and filled with gutta-percha using a cold lateral condensation technique, by 4th grade undergraduate students. Periapical radiographs were used to assess the technical quality of the root canal filling, evaluating three variables: length, density and taper. These data were recorded, scored and used to study the “technical success rate” and the “overall score”. The length of each root canal filling was classified as acceptable, short and overfilled, based on their relationship with the radiographic apex. Density and taper of filling were evaluated based on the presence of voids and the uniform tapering of the filling, respectively. Statistical analysis was used to evaluate the quality of root canal treatment, considering p < 0.05 as a statistical significant level. Results: The percentage of technical success was 44% and the overall score was 7.8 out of 10. Technical success and overall score were greater with rotary instruments (52% against 28% with a manual one, p < 0.001; 8.3 against 6.7 respectively, p < 0.001). Conclusions: It appears that inexperienced operators perform better root canal treatment (RCT) with the use of rotary instrumentation. Key words:Dental education, endodontics, rotary instrumentation, radiographs, root canal treatment, undergraduate students. PMID:24121911

Ethnic differences in oral health and use of dental services: cross-sectional study using the 2009 Adult Dental Health Survey.

PubMed

Arora, Garima; Mackay, Daniel F; Conway, David I; Pell, Jill P

2016-06-16

Oral health impacts on general health and quality of life, and oral diseases are the most common non-communicable diseases worldwide. Non-White ethnic groups account for an increasing proportion of the UK population. This study explores whether there are ethnic differences in oral health and whether these are explained by differences in sociodemographic or lifestyle factors, or use of dental services. We used the Adult Dental Health Survey 2009 to conduct a cross-sectional study of the adult general population in England, Wales and Northern Ireland. Ethnic groups were compared in terms of oral health, lifestyle and use of dental services. Logistic regression analyses were used to determine whether ethnic differences in fillings, extractions and missing teeth persisted after adjustment for potential sociodemographic confounders and whether they were explained by lifestyle or dental service mediators. The study comprised 10,435 (94.6 %) White, 272 (2.5 %) Indian, 165 (1.5 %) Pakistani/Bangladeshi and 187 (1.7 %) Black participants. After adjusting for confounders, South Asian participants were significantly less likely, than White, to have fillings (Indian adjusted OR 0.25, 95 % CI 0.17-0.37; Pakistani/Bangladeshi adjusted OR 0.43, 95 % CI 0.26-0.69), dental extractions (Indian adjusted OR 0.33, 95 % CI 0.23-0.47; Pakistani/Bangladeshi adjusted OR 0.41, 95 % CI 0.26-0.63), and <20 teeth (Indian adjusted OR 0.31, 95 % CI 0.16-0.59; Pakistani/Bangladeshi adjusted OR 0.22, 95 % CI 0.08-0.57). They attended the dentist less frequently and were more likely to add sugar to hot drinks, but were significantly less likely to consume sweets and cakes. Adjustment for these attenuated the differences but they remained significant. Black participants had reduced risk of all outcomes but after adjustment for lifestyle the difference in fillings was attenuated, and extractions and tooth loss became non-significant. Contrary to most health inequalities, oral health was

Coordinating a Large, Amalgamated REU Program with Multiple Funding Sources

ERIC Educational Resources Information Center

Fiorini, Eugene; Myers, Kellen; Naqvi, Yusra

2017-01-01

In this paper, we discuss the challenges of organizing a large REU program amalgamated from multiple funding sources, including diverse participants, mentors, and research projects. We detail the program's structure, activities, and recruitment, and we hope to demonstrate that the organization of this REU is not only beneficial to its…

DENTAL PULP TISSUE ENGINEERING

PubMed Central

Demarco, FF; Conde, MCM; Cavalcanti, B; Casagrande, L; Sakai, V; Nör, JE

2013-01-01

Dental pulp is a highly specialized mesenchymal tissue, which have a restrict regeneration capacity due to anatomical arrangement and post-mitotic nature of odontoblastic cells. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial material cause loss of a significant amount of dentin leaving as life-lasting sequelae a non-vital and weakened tooth. However, regenerative endodontics is an emerging field of modern tissue engineering that demonstrated promising results using stem cells associated with scaffolds and responsive molecules. Thereby, this article will review the most recent endeavors to regenerate pulp tissue based on tissue engineering principles and providing insightful information to readers about the different aspects enrolled in tissue engineering. Here, we speculate that the search for the ideal combination of cells, scaffolds, and morphogenic factors for dental pulp tissue engineering may be extended over future years and result in significant advances in other areas of dental and craniofacial research. The finds collected in our review showed that we are now at a stage in which engineering a complex tissue, such as the dental pulp, is no longer an unachievable and the next decade will certainly be an exciting time for dental and craniofacial research. PMID:21519641

Decontamination methods using a dental water jet and dental floss for microthreaded implant fixtures in regenerative periimplantitis treatment.

PubMed

Park, Shin-Young; Kim, Kyoung-Hwa; Shin, Seung-Yun; Koo, Ki-Tae; Lee, Yong-Moo; Chung, Chong-Pyoung; Seol, Yang-Jo

2015-06-01

This study evaluated decontamination methods using a dental water jet and dental floss on microthreaded implants for regenerative periimplantitis therapy. In 6 beagle dogs, experimental periimplantitis was induced, and decontamination procedures, including manual saline irrigation (control group), saline irrigation using a dental water jet (group 1) and saline irrigation using a dental water jet with dental flossing (group 2), were performed. After in situ decontamination procedures, some of the implant fixtures (n = 4 per group) were retrieved for analysis by SEM, whereas other fixtures (n = 4 per group) underwent regenerative therapy. After 3 months of healing, the animals were killed. The SEM examination indicated that decontamination of the implant surfaces was the most effective in group 2, with no changes in implant surface morphology. The histological examination also revealed that group 2 achieved significantly greater amounts of newly formed bone (6.75 ± 2.19 mm; P = 0.018), reosseointegration (1.88 ± 1.79 mm; P = 0.038), and vertical bone fill (26.69 ± 18.42%; P = 0.039). Decontamination using a dental water jet and dental floss on microthreaded implants showed positive mechanical debridement effects and positive bone regeneration effects.

Glutathione enzyme and selenoprotein polymorphisms associate with mercury biomarker levels in Michigan dental professionals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goodrich, Jaclyn M.; Wang, Yi; Gillespie, Brenda

Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione s-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n = 515), and total mercury content wasmore » measured. Average urine (1.06 {+-} 1.24 ug/L) and hair mercury levels (0.49 {+-} 0.63 ug/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5 Prime ), or both (SEPP1 3 Prime UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption). -- Highlights: Black-Right-Pointing-Pointer We explore the influence of 15 polymorphisms on urine and hair Hg levels. Black-Right-Pointing-Pointer Urine and hair Hg levels in dental professionals were similar to the US population. Black-Right-Pointing-Pointer GSTT1 and SEPP1 polymorphisms associated with urine Hg levels. Black

A Retrospective Audit of Dental Treatment Provided to Special Needs Patients under General Anesthesia During a Ten-Year Period.

PubMed

Mallineni, Sreekanth Kumar; Yiu, Cynthia Kar Y

The purpose of this study was to perform a comprehensive audit of dental treatment provided to special needs patients (SNP) under general anesthesia (GA) over a ten-year period. Special needs patients who received dental treatment under GA as an in-patient at Queen Mary Hospital, Hong Kong SAR during the time period January 2002 and December 2011 were included in the study. The study population was divided into three groups, based on age (<6years, 6-12 years, >12 years). One-way ANOVA was used to evaluate the effect of "age group" on duration of treatment, post-recovery time, treatment procedures and utilization of different restorative materials. Kappa statistics were used for intra-examiner reliability. A total of 275 patients (174 males and 101 females) were included in the study. The mean age of the patients at the time they received GA was 12.37±10.18 years. Dental procedures performed were mostly restorative in nature (47%). The >12 years group had significantly shorter treatment duration (p<0.05). No significant difference in post-operative recovery time was observed among the three age groups (p>0.05). The <6 years group received significantly less preventive, but more restorative procedures (p<0.05). Significantly fewer extractions were performed in the 6-12 years group (p<0.05). The use of composite restorations was significantly higher in the <6 years group; while amalgam restorations were more frequently used in the >12 years group (P<0.05). Stainless steel crowns were more frequently employed in SNP under 12 years of age (p<0.05). Intra-examiner reliability was good (k=0.94). Most of the dental procedures performed under GA on SNP were restorative procedures. For children less than 6 years of age, had longer treatment time under GA. Composite restorations and stainless steel crowns were more frequently used in the primary dentition and amalgam restorations were more frequently employed in the permanent dentition.

An estimated carbon footprint of NHS primary dental care within England. How can dentistry be more environmentally sustainable?

PubMed

Duane, B; Lee, M Berners; White, S; Stancliffe, R; Steinbach, I

2017-10-27

Introduction National Health Service (NHS) England dental teams need to consider from a professional perspective how they can, along with their NHS colleagues, play their part in reducing their carbon emissions and improve the sustainability of the care they deliver. In order to help understand carbon emissions from dental services, Public Health England (PHE) commissioned a calculation and analysis of the carbon footprint of key dental procedures.Methods Secondary data analysis from Business Services Authority (BSA), Health and Social Care Information Centre (HSCIC) (now called NHS Digital, Information Services Division [ISD]), National Association of Specialist Dental Accountants (NASDA) and recent Scottish papers was undertaken using a process-based and environmental input-output analysis using industry established conversion factors.Results The carbon footprint of the NHS dental service is 675 kilotonnes carbon dioxide equivalents (CO2e). Examinations contributed the highest proportion to this footprint (27.1%) followed by scale and polish (13.4%) and amalgam/composite restorations (19.3%). From an emissions perspective, nearly 2/3 (64.5%) of emissions related to travel (staff and patient travel), 19% procurement (the products and services dental clinics buy) and 15.3% related to energy use.Discussion The results are estimates of carbon emissions based on a number of broad assumptions. More research, education and awareness is needed to help dentistry develop low carbon patient pathways.

Long-term effects of chemotherapy on dental status of children cancer survivors.

PubMed

Nemeth, Orsolya; Hermann, Peter; Kivovics, Peter; Garami, Miklos

2013-04-01

The aim of this study was to investigate the long-term effects of chemotherapy on the dental and gingival health and dental disturbance parameters of children cancer survivors. Thirty-eight children (mean age 12.2 ± 0.5 years) who underwent chemotherapy at 4.29 ± 1.71 years of age formed the study group. Forty age- and gender-matched healthy children with a similar socioeconomic background served as controls. Subjects' caries status (number of decayed, missing, or filled permanent teeth [DMF-T]) was recorded according to World Health Organization criteria. Subjects' periodontal status was recorded according to the community periodontal index system. Radiographic dental examination was used to analyze dental malformations. DMF-T, D-T (number of decayed permanent teeth), and F-T (number of filled permanent teeth) were significantly higher in the study group compared to the controls (4.61 ± 3.71, 3.97 ± 4.45, respectively, and 0.58 ± 0.14 vs. 2.21 ± 1.01, 0.84 ± 1.82, and 1.18 ±1.07, respectively. The most frequent dental disturbances were root malformation (52.6%) and agenesis (47.4%). According to our examination dental status of long-term survivors is worse than in controls. Hence proper oral hygiene for children cancer survivors (CCS) is critical. In order to meet the need for dental care in CCS health authorities are encouraged to revitalize the dental services Long-term follow-up of CCS is necessary to monitor their dental growth and oral health.

Composite Replacement of Amalgam Restoration Versus Freshly Cut Dentin: An In Vitro Microleakage Comparison.

PubMed

Redwan, H; Bardwell, D N; Ali, A; Finkelman, M; Khayat, S; Weber, H-P

2016-01-01

The aim of this study was to evaluate the microleakage of the composite restorations when bonded to tooth structure previously restored with amalgam material compared with that of freshly cut dentin. Thirty intact, extracted intact human molars were mounted in autopolymerizing acrylic resin. Class II box preparations were prepared on the occluso-proximal surfaces of each tooth (4-mm bucco-lingual width and 2-mm mesio-distal depth) with the gingival cavosurface margin 1 mm above the CEJ. Each cavity was then restored using high copper amalgam restoration (Disperalloy, Dentsply) and then thermocycled for 10,000 thermal cycles. Twenty-five of the amalgam restorations were then carefully removed and replaced with Filtek Supreme Ultra Universal (3M ESPE); the remaining five were used for scanning electron microscopy and energy dispersive x-ray spectroscopy analysis. A preparation of the same dimensions was performed on the opposite surface of the tooth and restored with composite resin and thermocycled for 5000 thermal cycles. Twenty samples were randomly selected for dye penetration testing using silver nitrate staining to detect the microleakage. The specimens were analyzed with a stereomicroscope at a magnification of 20×. All of the measurements were done in micrometers; two readings were taken for each cavity at the occlusal and proximal margins. Two measurements were taken using a 0-3 scale and the percentage measurements. Corrosion products were not detected in either group (fresh cut dentin and teeth previously restored with amalgam). No statistically significant difference was found between the microleakage of the two groups using a 0-3 scale at the occlusal margins (McNemar test, p=0.727) or proximal margins (Wilcoxon signed-rank test, p=0.174). No significance difference was found between the two groups using the percentage measurements and a Wilcoxon signed-rank test at either the occlusal (p=0.675) or proximal (p=0.513) margins. However, marginal

In vitro corrosion behaviour and microhardness of high-copper amalgams with platinum and indium.

PubMed

Ilikli, B G; Aydin, A; Işimer, A; Alpaslan, G

1999-02-01

Samples prepared from Luxalloy, GS-80, Permite-C and Logic and polished after 24 h by traditional methods were stored in polypropylene tubes containing phosphate-buffered saline solutions (pH 3.5 and 6.5) and distilled water. The amounts of mercury, silver, tin, copper, zinc, platinum and indium in the test solutions were determined at the first, second, eighth, 52nd and 78th week by atomic absorption spectrometry. At the end of the eighth week the amalgam samples were removed from solutions and evaluated by Rockwell Super Scial Microhardness tester. Statistically significant low amounts of metal ions were measured for Permite-C containing indium and Logic containing platinum. The microhardness test results showed that there were statistically significant increases in the microhardness of Permite-C and Logic. As a result it was shown that the amalgam samples were affected from corrosion conditions to different degrees. Sample of the Logic group that was stored in distilled water, showed smoother surface properties than other amalgam samples containing high copper. However, it was observed that samples of Permite-C group had the smoothest surface properties.

Versatile combustion-amalgamation technique for the photometric determination of mercury in fish and environmental samples

USGS Publications Warehouse

Willford, Wayne A.; Hesselberg, Robert J.; Bergman, Harold L.

1973-01-01

Total mercury in a variety of substances is determined rapidly and precisely by direct sample combustion, collection of released mercury by amalgamation, and photometric measurement of mercury volatilized from the heated amalgam. Up to 0.2 g fish tissue is heated in a stream of O2 (1.2 L/min) for 3.5 min in 1 tube of a 2-tube induction furnace. The released mercury vapor and combustion products are carried by the stream of O2 through a series of traps (6% NaOH scrubber, water condenser, and Mg(CIO4)2 drying tube) and the mercury is collected in a 10 mm diameter column of 24 gauge gold wire (8 g) cut into 3 mm lengths. The resulting amalgam is heated in the second tube of the induction furnace and the volatilized mercury is measured with a mercury vapor meter equipped with a recorder-integrator. Total analysis time is approximately 8 min/sample. The detection limit is less than 0.002 μg and the system is easily converted for use with other biological materials, water, and sediments.

[Microinvasive dental treatment in pre-school children].

PubMed

Korolenkova, M V

The aim of the study was to assess the efficiency of atraumatic restorative treatment (ART) with cavity preparation by means of dental endo motor. ART method was applied in 94 children (50 females and 44 males, 301 teeth treated) aged 21-96 months. Wireless dental endo motor (Endo Mate TC2, NSK, Japan) was used for cavity preparation. The cavities (102 (33.9%) class I, 156 (51.8%) class V, 20 (6.6%) class II, 18 (6%) class III and 5 (1.7%) class IV) were then filled with glass-ionomer cement (Fuji IX, GC, Japan). Success rate was assessed 3, 6, 12 and 18 months after treatment. Overall ART procedure success rate (good marginal fit, no occlusal wearing or restoration fractures) at 18-month follow up was 88.7% (267 fillings out of 301) with the highest survival in class I (96.1%) and class V (96.2%) restoration and poorest in class II (50%), class III (44.4%) and class IV (20%) restorations. Cavity preparation with wireless dental endo motor was well tolerated even by infants (12 children were younger than 24 months), as it is noiseless and significantly faster than conventional manual preparation. ART method with the use of dental endo motor showed good success rate and proved to be highly efficient in small and apprehensive children. The method, however, should be avoided in class III and IV cavities as the success rate is poor mostly because of restoration fractures.

Dental therapists linked to improved dental outcomes for Alaska Native communities in the Yukon-Kuskokwim Delta.

PubMed

Chi, Donald L; Lenaker, Dane; Mancl, Lloyd; Dunbar, Matthew; Babb, Michael

2018-01-29

Dental Health Aide Therapists (DHATs) have been part of the dental workforce in Alaska's Yukon-Kuskokwim (YK) Delta since 2006. They are trained to provide preventive and restorative care such as filling and extractions. In this study, we evaluated community-level dental outcomes associated with DHATs. This was a secondary data analysis of Alaska Medicaid and electronic health record data for individuals in Alaska's YK Delta (2006-2015). The independent variable was the number of DHAT treatment days in each community. Child outcomes were preventive care, extractions, and general anesthesia. Adult outcomes were preventive care and extractions. We estimated Spearman partial correlation coefficients to test our hypotheses that increased DHAT treatment days would be associated with larger proportions utilizing preventive care and smaller proportions receiving extractions at the community-level. DHAT treatment days were positively associated with preventive care utilization and negatively associated with extractions for children and adults (P < 0.0001). DHAT treatment days were not associated with increased dental treatment under general anesthesia for children. Dental therapists are associated with more preventive care and fewer extractions. State-level policies should consider dental therapists as part of a comprehensive solution to meet the dental care needs of individuals in underserved communities and help achieve health equity and social justice. © 2018 American Association of Public Health Dentistry.

Ethnic inequalities in dental caries among adults in East London.

PubMed

Delgado-Angulo, Elsa K; Bernabé, Eduardo; Marcenes, Wagner

2016-06-01

This study explored ethnic inequalities in dental caries among adults and assessed the role of socioeconomic position (SEP) in explaining those inequalities. We analysed data on 2013 adults aged 16-65 years, from the East London Oral Health Inequality (ELOHI) Study, which included a random sample of adults and children living in East London in 2009-10. Participants completed a questionnaire and were clinically examined for dental caries at home. Dental caries was measured using the number of decayed, missing and filled teeth or DMFT index. Ethnic inequalities in dental caries were assessed in negative binomial regression models before and after adjustment for demographic (sex and age groups) and SEP measures (education and socioeconomic classification). White Eastern European and White Other had higher DMFT, whereas all Asian (Pakistani, Indian, Bangladeshi and Other) and all Black (African, Caribbean and Other) ethnic groups had lower DMFT than White British. Similar inequalities were found for the number of filled and missing teeth, but there were no differences in the number of decayed teeth between ethnic groups. This study showed considerable disparities in dental caries between and within the major ethnic categories, which were independent of demographics and SEP. © The Author 2015. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Comparison of cutting efficiencies between electric and air-turbine dental handpieces.

PubMed

Choi, Charlson; Driscoll, Carl F; Romberg, Elaine

2010-02-01

Dentistry is gravitating toward the increased use of electric handpieces. The dental professional should have sufficient evidence to validate the switch from an air-turbine handpiece to an electric handpiece. However, there is little research quantifying the cutting efficiency of electric and air-turbine handpieces. Studies that do quantify cutting efficiency typically do so with only a single material. The purpose of this study was to compare the cutting efficiency of an electric handpiece and an air-turbine handpiece, using various materials commonly used in dentistry. Seven materials: Macor (machinable glass ceramic), silver amalgam, aluminum oxide, zirconium oxide, high noble metal alloy, noble metal alloy, and base metal alloy, were each cut with a bur 220 times; 110 times with an electric handpiece, and 110 times with an air-turbine handpiece. The weight difference of the material was calculated by subtracting the weight of the material after a cut from the weight of the material before the cut. The cutting efficiency was calculated by dividing the weight difference by the duration of the cut (g/s). Data were analyzed by a 2-way analysis of variance followed by Tukey's Honestly Significant Difference (HSD) test (alpha=.05). The electric handpiece cut more efficiently than the air-turbine handpiece (F=3098.9, P<.001). In particular, the high noble metal alloy, silver amalgam, and Macor were cut more efficiently with the electric handpiece (0.0383 +/-0.0002 g/s, 0.0260 +/-0.0002 g/s, and 0.0122 +/-0.0002 g/s, respectively) than with the air-turbine handpiece (0.0125 +/-0.0002 g/s, 0.0142 +/-0.0002 g/s, and 0.008 +/-0.0002 g/s, respectively). The electric handpiece is more efficient at cutting various materials used in dentistry, especially machinable glass ceramic, silver amalgam, and high noble alloy, than the air-turbine handpiece.

Toxic heavy metals in human blood in relation to certain food and environmental samples in Kerala, South India.

PubMed

Jose, Anitha; Ray, Joseph George

2018-03-01

Toxic heavy metals such as arsenic (As), lead (Pb), and mercury (Hg) are systemic toxicants that are hazardous to human health. However, as these elements are increasing in the environment due to fast urbanization, industrialization, and chemicalized agricultural activities, accumulation of the same in human body anywhere in the world is quite interesting to global assessment of environment quality. In this connection, random examination of blood samples of human population in Kerala, South India, was carried out to assess the threat of heavy metal contamination to humans in this part of the globe, especially in relation to the amount of such metals in food and other environmental samples. Except pure vegetarians, people of Kerala consume rice as the staple food with a lot of fish. Therefore, the amount of these three heavy metals in drinking water, fish, rice, and paddy soils was done. Heavy metals in the blood were examined in relation to age, gender, and dietary habits such as frequency of fish eating or vegetarianism. Influence of dental amalgam fillings on blood mercury levels was also analyzed. Quantitative assessment of metals in samples was done by inductively coupled plasma-mass spectrometry (ICP-MS). The levels of arsenic, lead, and mercury were found well below the reference values, though diet seemed to pull them up as the amount of metals in blood showed significant differences between vegetarians and non-vegetarians. Evidence to the influence of dental amalgam fillings on blood mercury levels could not be established with the present samples.

The frequency of replacement of dental restorations may vary based on a number of variables, including type of material, size of the restoration, and caries risk of the patient.

PubMed

Roumanas, Eleni D

2010-03-01

The authors analyzed the dental records of 2780 Navy (cohort 1 = 1078 entered the Navy in 1997) and US Marine Corps recruits (cohort 2 =1053 entered the USMC in 1999-2000; cohort 3 = 649 entered the USMC in 2002-2005). The records were reviewed at 16 US Navy dental treatment facilities at the following time periods: cohort 1, 2001; cohort 2, 2002-2003; and cohort 3, 2005-2006. The mean age of the subjects was 20 years, and 85% were men. Only posterior teeth (not third molars) with amalgam or resin-based composite (including glass ionomer restorations) were evaluated. Teeth that had been restored with more than one material and restorations that did not involve the occlusal surface were excluded. The minimum follow-up time was 2 years with at least 2 periodic exams following the initial exam. The primary factor of interest was the type of restorative material (amalgam versus resin-based composite). Secondary factors included tooth number, number of restored surfaces (single or multiple), and caries risk of the patient. Caries risk status was defined using the Navy Dental Corps Oral Disease Risk Management protocol. The primary outcome measure of interest was the determination of the relative risk of replacement of an initially intact restoration during the subject's first years of military service. Restorations were classified as clinically acceptable or requiring replacement either as a result of new primary caries, secondary caries, defective restorations, or endodontic therapy. At the initial exam, 964 (15.2%) of the amalgam restorations and 199 (17.4%) of the resin-based composites required replacement and were excluded from further analysis. Of the remaining restorations, an additional 14.2% of the amalgam and 16.7% of the composite restorations required replacement during the observation period. The mean follow-up time was 3.0 years (cohort 1, 3.4 years; cohort 2, 3.1 years; cohort 3, 2.3 years). Replacement rates for resin-based composite restorations

[Association between preventive care provided in public dental services and caries prevalence].

PubMed

Celeste, Roger Keller; Nadanovsky, Paulo; De Leon, Antonio Ponce

2007-10-01

To assess the association between preventive care provided in public dental services and young people's oral health. Oral health data on 4,033 young people aged 15 to 19 years living in 85 municipalities of the state of Rio Grande do Sul, Southern Brazil, were obtained from the national oral health survey "Saúde Bucal Brasil 2003" for the period 2002-2003. The following variables were studied: age, gender, income, education, time elapsed since last dental visit, reason for dental visit, and water fluoridation. Data on dental care services were obtained from the national database of public health services. Statistical analysis was performed using multilevel logistic regression. Youngsters from the 21 municipalities with the lowest preventive care (scaling + fluoride + sealants) rates per 100 inhabitants were 2.27 (95% CI: 1.45;3.56) more likely to have non-filled dental cavities than those from the 21 municipalities with the highest care rates. After adjustment for a number of individual and contextual factors this likelihood decreased to 1.76 (95% CI: 1.13;2.72). The variance attributable to variables at municipal level was 14.1% for the empty model and decreased to 10.5% for the fully adjusted model. Rio Grande do Sul public dental services may have contributed for the reduction in the number of non-filled cavities in young people. However, it was not possible to detect the impact of this service on total dental caries experience.

Disability self-assessment and upper quarter muscle balance between female dental hygienists and non-dental hygienists.

PubMed

Johnson, Eric G; Godges, Joseph J; Lohman, Everett B; Stephens, Joni A; Zimmerman, Grenith J; Anderson, Sharon P

2003-01-01

The purpose of this pilot study was to compare disability self-assessment and upper quarter muscle balance female dental hygienists and non dental hygienist females. The upper quarter was operationally defined as the shoulder and neck region. Muscle balance was operationally defined as muscle flexibility and muscle performance. A convenience sample of 41 working dental hygienists and 46 non dental hygienists participated in the study. Muscle flexibility of the upper quarter was measured by inclinometry or standard muscle length testing. Muscle performance was measured by timing the duration of four statically maintained positions. Subjects filled out the Northwick Park Neck Pain Questionnaire (NPNPQ), which is a disability self-assessment. Analysis of Covariance (ANCOVA) was used during data analysis to adjust for the mean age difference between the dental hygienist group (38.0 years) and the non-dental hygienist group (29.3 years). The results of this pilot study suggest that female dental hygienists are more likely than non dental hygienist females to develop tightness in the upper trapezius (p = 0.007) and the levator scapula (p = 0.01) of the non dominant upper quarter and lower fibers of the pectoralis major of the dominant upper quarter (p = 0.03) Muscle performance trends in the dental hygienist group supported muscle balance theory that short muscles remain strong while lengthened muscles become weak. The dental hygienist group had higher disability scores in all nine parts of the NPNPQ compared to the non-dental hygienist group, five of which were statistically significant (p < 0.05). The results of this pilot study suggest that muscle imbalances in the upper quarter are more common in female dental hygienists than in female non dental hygienists and may contribute to the numerous upper quarter pathologies associated with the practice of dental hygiene. Further research is needed to determine if upper quarter strengthening and flexibility exercises

Child dental anxiety, parental rearing style and referral status of children.

PubMed

Krikken, J B; van Wijk, A J; ten Cate, J M; Veerkamp, J S J

2012-12-01

Treating children can be difficult for both dentist and child. In some cases treatment fails and those children are referred to a specialist paediatric dentist. Different factors can be put forward for referral of children, such as factors relating to the child, dentist and parent. Possible child-related factors can be dental anxiety and the child's temperament. A possible parental factor is the parental rearing style. The objective of this study was to assess the possible associations between dental anxiety, parental rearing style and referral status of children. Parents of 120 non-referred and 335 referred paediatric dental patients were asked to fill out the Child Rearing Practices Report (CRPR) and the Child Fear Survey Schedule Dental Subscale (CFSS-DS) on behalf of their children. The questionnaires were filled out by 115 (96%) parents of primary schoolchildren and by 331 (99%) parents of referred children. Referred children were younger than non-referred children, t(442) = 6.9, p < 0.01, and had significantly more dental anxiety, t(430) = -8.7, p < 0.01. No differences existed between parents of referred children and parents of non-referred children on parental rearing-style. No differences existed between fearful and non-fearful children on parental rearing-style and also no correlation existed between children's dental anxiety and their parent's rearing style. However, non-referred children with parents using an authoritarian parenting style were more anxious than the other non-referred children. In the present study, referral status and dental anxiety of 4-12 year old children were not associated with parental rearing style.

Willingness and ability to pay for unexpected dental expenses by Finnish adults

PubMed Central

2012-01-01

Background Since 2002, adults have been able to choose oral health care services in the public sector or in the private sector in Finland. Though various subsidies for care exist in both sectors, the Public Dental Service (PDS) is a cheaper option for the patient but, on the other hand, there are no waiting lists for private care. The aim of this study was to assess middle-aged adults' use of dental services, willingness to pay (WTP) and ability to pay (ATP) for unexpected, urgent dental treatment. Methods Postal questionnaires on use of dental services were sent to a random sample of 1500 47-59 year old adults living in three large municipalities in the Helsinki region. The initial response rate was 65.8%. Two hypothetical scenarios were presented: "What would be the highest price you would be prepared to pay to have a lost filling replaced immediately, or, at the latest, the day after losing the filling?" and " How much could you pay for unexpected dental expenses at two weeks notice, if you suddenly needed more comprehensive treatment?" Logistic regression analysis was used to analyse factors related to WTP and ATP. Results Most respondents (89.6%) had visited a dentist recently and a majority (76.1%) had used private services. For immediate replacement of a lost filling, almost all respondents (93.2%) were willing to pay the lower price charged in the PDS and 46.2% were willing to pay the private fee. High income and no subjective need for dental treatment were positively associated with the probability of paying a higher price. Most respondents (93.0%) were able to pay a low fee, EUR 50 and almost half (41.6%) at least EUR 300 for unexpected treatment at short notice. High income and male sex were associated with high ATP. Conclusion There was a strong and statistically significant relationship between income and WTP and ATP for urgent dental care, indicating that access to publicly provided services improved equity for persons with low income. PMID:22935077

Cyclic Voltammetry Probe Approach Curves with Alkali Amalgams at Mercury Sphere-Cap Scanning Electrochemical Microscopy Probes.

PubMed

Barton, Zachary J; Rodríguez-López, Joaquín

2017-03-07

We report a method of precisely positioning a Hg-based ultramicroelectrode (UME) for scanning electrochemical microscopy (SECM) investigations of any substrate. Hg-based probes are capable of performing amalgamation reactions with metal cations, which avoid unwanted side reactions and positive feedback mechanisms that can prove problematic for traditional probe positioning methods. However, prolonged collection of ions eventually leads to saturation of the amalgam accompanied by irreversible loss of Hg. In order to obtain negative feedback positioning control without risking damage to the SECM probe, we implement cyclic voltammetry probe approach surfaces (CV-PASs), consisting of CVs performed between incremental motor movements. The amalgamation current, peak stripping current, and integrated stripping charge extracted from a shared CV-PAS give three distinct probe approach curves (CV-PACs), which can be used to determine the tip-substrate gap to within 1% of the probe radius. Using finite element simulations, we establish a new protocol for fitting any CV-PAC and demonstrate its validity with experimental results for sodium and potassium ions in propylene carbonate by obtaining over 3 orders of magnitude greater accuracy and more than 20-fold greater precision than existing methods. Considering the timescales of diffusion and amalgam saturation, we also present limiting conditions for obtaining and fitting CV-PAC data. The ion-specific signals isolated in CV-PACs allow precise and accurate positioning of Hg-based SECM probes over any sample and enable the deployment of CV-PAS SECM as an analytical tool for traditionally challenging conditions.

Dental health and treatment needs among children in a tribal community.

PubMed

Viragi, Prashant S; Dwijendra, K S; Kathariya, Mitesh D; Chopra, Kirti; Dadpe, Mahesh V; Madhukar, H S

2013-07-01

To assess the dental health status and treatment needs among children of 'Pardhi' tribal community. A total of 185 children were examined over a period of 2 months using WHO proforma. The statistical software namely SPSS version 15.0 and data was analyzed using Student's t-test and ANOVA test at p < 0.05. The mean score for dft and DMFT was 1.87 ± 1.073 and 2.04 ± 1.564 respectively with males subjects were having comparatively more scores. It was also found significant differences between age groups. Most of the children needed one surface filling, i.e. 29.40%, followed by pulp care and restoration (19.30%), two or more surface fillings (15.60%) and extraction (11.70%). The study subjects were characterized by a lack of dental care services, high prevalence of dental caries and treatment needs. Therefore, implementation of a basic oral health care program for this tribal population is a high priority.

Clinical Guidelines and Implementation into Daily Dental Practice.

PubMed

Guncu, Guliz Nigar; Nemli, Secil Karakoca; Carrilho, Eunice; Yamalık, Nermin; Volodina, Elena; Melo, Paulo; Margvelashvili, Vladimer; Rossi, Alessandra

2018-01-31

The purpose of this study is to assess the extent of the familiarity, attitude and perceptions of dental professionals regarding clinical dental guidelines and their implementation into daily dental practice. For this purpose, a questionnaire which was developed by the members of the World Dental Federation, European Regional Organization Working Group - 'Relation Between Dental Practitioner and Universities', was implemented by the National Dental Associations of six European Regional Organization-zone countries (Georgian Stomatological Association - Georgia, Associazione Nazionale Dentisti Italiani - Italy, Portuguese Dental Association - Portugal, Russian Dental Association - Russia, Swiss Dental Association - Switzerland, and Turkish Dental Association - Turkey. The questionnaire was filled by a total of 910 dental professionals who are members of one of these national dental associations and who voluntarily wanted to participate to this survey. Most of the survey participants were familiar with clinical dental guidelines (68%), claimed that they implemented them into daily practice (61.7%), and generally acknowledged their benefits (81.8%). Many participants believed that clinical dental guidelines could help to improve the clinical treatment plan (50.6 %) and the accuracy of diagnosis (39.4%); which increased with age and years of practice (p < 0.05). The most frequently perceived barrier to the effective implementation of clinical dental guidelines was expressed as 'lack of awareness', while participants suggested a role for national dental associations in spreading clinical dental guidelines. A better understanding of the perceptions and attitudes of dentists towards clinical dental guidelines and the potential impact of factors affecting such perceptions and attitudes may be of particular importance for attempts aiming at overcoming the barriers for effective implementation of clinical dental guidelines into daily practice. Despite a significant

Dentists' restorative decision-making and implications for an 'amalgamless' profession. Part 4: clinical factor.

PubMed

Alexander, G; Hopcraft, M S; Tyas, M J; Wong, Rhk

2017-09-01

The Minamata Convention embodies a worldwide reduction in the production and use of mercury and mercury-containing products and processes, including a phase-down of dental amalgam. This will change the approach to the use of direct restorative materials in the near future. There is little research as to the influence of clinical factors on dentists' decision-making which may be of use when determining the impact of any change. An online survey relating to aspects of and attitudes to the use of direct restorative materials was distributed to all dentists who were members of the Australian Dental Association and/or members or fellows of the Royal Australasian College of Dental Surgeons. Data were statistically analysed. There were 408 respondents to the survey. Eighty-seven per cent of respondents (strongly) disagreed that amalgam was a technically more difficult material to place compared with resin composite, 82% (strongly) disagreed that placement time for amalgam was longer than that for resin composite and 69% (strongly) disagreed that amalgam was more difficult to finish than resin composite. Eighty-three per cent of respondents stated they were confident in their ability to place amalgam restorations. Where physical properties were of importance, indirect restorations were preferred (e.g. parafunction) 54%. The factors considered most important when choosing a direct restorative material included moisture control and aesthetics; least important factors were cost and time to place. There is consensus that amalgam is not more technically difficult to use, place or finish than resin composite and vice versa. There is recognition that both amalgam and resin composite have limitations in terms of physical properties. When choosing a direct restorative material, clinical factors considered to be of greatest importance are moisture control, aesthetics and the need to apply minimally invasive approaches. There is little difference in the opinions of users and non

Prevalence of dental caries among 12-14 year old children in Qatar.

PubMed

Al-Darwish, Mohammed; El Ansari, Walid; Bener, Abdulbari

2014-07-01

To ensure the oral health of a population, clinicians must deliver appropriate dental services, and local communities need to have access to dental care facilities. However, establishment of this infrastructure must be based on reliable information regarding disease prevalence and severity in the target population. The aims of this study were to measure the incidence of dental caries in school children aged 12-14 throughout Qatar, including the influence of socio-demographic factors. A cross-sectional study was conducted in Qatar from October 2011 to March 2012. A total of 2113 children aged 12-14 were randomly selected from 16 schools located in different geographic areas. Three calibrated examiners using World Health Organization (WHO) criteria to diagnose dental caries performed the clinical examinations. Data analyses were subsequently conducted. The mean decayed, missing, and filled teeth index values were respectively 4.62 (±3.2), 4.79 (±3.5), and 5.5 (±3.7), for 12, 13, and 14 year-old subjects. Caries prevalence was 85%. The mandibular incisors and canines were least affected by dental caries, while maxillary and mandibular molars exhibited the highest incidence of dental caries. Dental caries were affected by socio-demographic factors; significant differences were detected between female and male children, where more female children showed dental caries than male children. In addition, children residing in semi-urban areas showed more dental caries than in urban areas. Results indicated that dental caries prevalence among school children in Qatar has reached critical levels, and is influenced by socio-demographic factors. The mean decayed, missing, and filled teeth values obtained in this study were the second highest detected in the Eastern Mediterranean region.

[Influence of the effect of general anaesthesia and restraint during dental treatment on dental anxiety and behavior in children].

PubMed

Zhang, Hong-mei; Xia, Bin; Wang, Jian-hong; Chen, Xiao-xian; Ge, Li-hong

2015-02-18

To compare the level of dental anxiety and dental behavior between dental fear children with dental treatment under general anaesthesia (GA) and those under restraint. The GA group included 31 dental fear children aged 4-6-year-old who received dental treatment under the GA. The restraint group included 31 dental fear children aged 4-6-year-old who received dental treatment under the restraint. Age, gender, parent's education level, decayed-missing-filled-tooth (dmft) and face version of the Modified Child Dental Anxiety Scale (MCDASf) score before treatment were matched between the two groups. The Chinese version of MCDASf was used to evaluate the level of dental anxiety in each child before treatment, right after treatment and before examination at recall visit 2-3 weeks after treatment. And the Chinese version of Venham Clinical Anxiety and Cooperative Behavior Scale was used to evaluate children's dental behavior in each child before treatment and before examination at recall visit 2-3 weeks after treatment. The average scores of MCDASf in GA group right after treatment and before recall were lower than that before treatment. The difference was statistically significant (P<0.05). Furthermore, the average score of MCDASf before recall was lower than those after treatment, and the difference was statistically significant (P<0.05). The average scores of MCDASf in restraint group right after treatment and 2-3 weeks after treatment were higher than those before treatment, but the difference was not statistically significant (P>0.05). Children's dental behavior was significantly improved at recall visit in both groups (P<0.01). Dental fear could be reduced by treatment under GA. The children's dental behavior was improved after GA. Restraint did not result in the significant elevation of dental anxiety level, but dental behavior was improved after restraint during the short-term recall.

Epidemiology of dental caries in children in the United Arab Emirates.

PubMed

Al-Bluwi, Ghada S M

2014-08-01

Dental caries has a significant impact on the general health and development of children. Understanding caries epidemiology is an essential task for the United Arab Emirates (UAE) policymakers to evaluate preventive programmes and to improve oral health. The purpose of this review is to collect and summarise all data available in the published literature on the epidemiology of dental caries in the UAE in children aged under 13 years. This will provide dental health planners with a comprehensive data summary, which will help in the planning for and evaluation of dental caries prevention programmes. Data were collected from the various published studies in PubMed, Academic Search Complete, Google, and the reference lists in relevant articles. Four keywords were used in the search: 'dental caries,' 'epidemiology,' 'prevalence,' and 'UAE'. All studies conducted in the UAE in general or any single emirate that sheds light on the prevalence of dental caries of children under 13 years were included in this literature review. Studies on early childhood caries and factors associated with dental caries were also included. The review comprises 11 published surveys of childhood caries in UAE. The earliest study was published in 1991 and the most recent was published in 2011. The range of decayed, missing and filled primary teeth (dmft) in UAE children (age between 4 years and 6 years) was 5.1-8.4. For the 12-year-old group the decayed missing and filled permanent teeth (DMFT) ranged from 1.6 to 3.24. Baseline data on oral health and a good understanding of dental caries determinants are necessary for setting appropriate goals and planning for preventive oral health programmes. The current data available on the dmft and DMFT indicate that childhood dental caries is still a serious dental public health problem in the UAE that warrants immediate attention by the government and policy makers. © 2014 FDI World Dental Federation.

Agreement Among Dental Students, Peer Assessors, and Tutor in Assessing Students' Competence in Preclinical Skills.

PubMed

Foley, Jennifer I; Richardson, Gillian L; Drummie, Joyce

2015-11-01

The aim of this study was to determine the level of agreement regarding assessments of competence among dental students, their student peers, and their clinical skills tutors in a preclinical skills program. In 2012-13 at the University of Edinburgh, second-year dental students learned to perform the following seven cavity preparations/restorations on primary and permanent Frasaco teeth: single-surface adhesive occlusal cavity; single-surface adhesive interproximal cavity; single-surface adhesive labial cavity; multi-surface adhesive cavity; multi-surface amalgam cavity; pre-formed metal crown preparation; and composite resin buildup of a fractured maxillary central incisor tooth. Each student, a randomly allocated student peer, and the clinical skills tutor used standardized descriptors to assign a competency grade to all the students' preparations/restorations. The grades were analyzed by chi-square analysis. Data were available for all 59 second-year students in the program. The results showed that both the students and their peers overestimated the students' competence compared to the tutor at the following levels: single-surface adhesive occlusal cavity (χ(2)=10.63, p=0.005); single-surface adhesive interproximal cavity (χ(2)=11.40, p=0.003); single-surface labial cavity (χ(2)=23.70, p=0.001); multi-surface adhesive cavity (χ(2)=12.56, p=0.002); multi-surface amalgam cavity (χ(2)=38.85, p=0.001); pre-formed metal crown preparation (χ(2)=40.41, p=0.001); and composite resin buildup (χ(2)=57.31, p=0.001). As expected, the lowest levels of agreement occurred on the most complicated procedures. These findings support the need for additional ways to help students better self-assess their work.

Quantitative detection of Streptococcus mutans in the dental plaque of Japanese preschool children by real-time PCR.

PubMed

Hata, S; Hata, H; Miyasawa-Hori, H; Kudo, A; Mayanagi, H

2006-02-01

To detect quantitatively the total bacteria and Streptococcus mutans in dental plaque by real-time PCR with prbac, Sm and GTF-B primers, and to compare their presence with the prevalence of dental caries in Japanese preschool children. Human dental plaque samples were collected from the labial surfaces of the upper primary central incisors of 107 children. The dental status was recorded as dft by WHO caries diagnostic criteria. Positive dt and dft scores by the Sm or GTF-B primer were significantly higher than negative scores (P < 0.01). The proportions of Strep. mutans to the total bacteria from sound, and sound and/or filled upper primary incisors were significantly lower than those from decayed or filled, and decayed incisors, respectively (P < 0.01). The ratios of Strep. mutans to total bacteria in plaque detected by real-time PCR with Sm and GTF-B primers were closely associated with the prevalence of dental caries in Japanese preschool children. These assays may be useful for the assessment of an individual's risk of dental caries.

Dental caries experience, rather than toothbrushing, influences the incidence of dental caries in young Japanese adults.

PubMed

Sonoda, C; Ebisawa, M; Nakashima, H; Sakurai, Y

2017-06-01

A dose-response relationship between toothbrushing frequency and the incidence of dental caries has not been confirmed. Furthermore, no longitudinal study about this relationship has considered dental caries experience at baseline, which is an important factor influencing the frequency of future caries. To elucidate the association between the incidence of dental caries and toothbrushing frequency after adjusting for dental caries experience at baseline in a Japanese population. The 92 recruits of the Japan Maritime Self-Defense Force in Kure, Japan, in 2011 were followed up for 3 years. They underwent oral examination at the annual checkups and answered questions about toothbrushing frequency. The multiple logistic regression analysis was used to analyze the incidence of dental caries and to identify independent effects of toothbrushing frequency and dental caries experience at baseline. Furthermore, the relative importance of the incidence of dental caries was investigated among other independent variables using the partial adjusted R² score. Logistic regression analysis showed that toothbrushing frequency alone did not influence the increment in decayed, missing, and filled teeth (DMFT). However, DMFT at baseline alone was associated with the increment in DMFT (crude odds ratio, OR, 1.20, 95% confidence interval, CI, 1.08,1.33). In the fully adjusted model, only DMFT at baseline was associated with the increment in DMFT (adjusted OR 1.23, 95%CI 1.09,1.38). After three years, the incidence of dental caries in young adult Japanese males was influenced by DMFT at baseline, rather than toothbrushing frequency. Copyright© 2017 Dennis Barber Ltd.

Evaluation of simulation learning materials use to fill the gap in Japanese dental English education.

PubMed

Seki, Naoko; Moross, Janelle; Sunaga, Masayo; Hobo, Koki; Miyoshi, Tomoe; Nitta, Hiroshi; Kinoshita, Atsuhiro; Morio, Ikuko

2016-01-01

Even though English is most frequently the common language when the patient's native language differs from that of a dentist, the opportunities for Japanese undergraduate dental students to learn dental English are now quite limited. The purposes of our study were to investigate: the effectiveness and feasibility of the computer-assisted simulation materials as one solution strategy for dental English education in Japan, and the needs and demands for dental English from the learners' side. Interactive simulation materials for medical interviews in English and clinical cases which were translated to English, were delivered via Learning Management System (LMS) to nineteen trainee residents of dentistry (residents). Evaluation for the materials, learners' knowledge and interests in the contents, and ease of operation were obtained by post-questionnaire (response rates were 100% and 95%, respectively). Both questionnaire-surveys received positive feedback toward the materials, yet 47% answered that they lacked the level of knowledge about contents of the medical interview in English. Results were sufficient to suggest that the residents would like to have the opportunity to study or practice medical interview in English, or English related to dentistry, and that the simulation materials could be one of the solution strategies for opportunity provision.

Dental caries and dental fluorosis among 4-, 6-, 12- and 15-year-old children in kindergartens and public schools in Kuwait.

PubMed

Vigild, M; Skougaard, M; Hadi, R A; al-Zaabi, F; al-Yasseen, I

1996-03-01

The purpose of the present study was 1) to describe the occurrence of dental caries and fluorosis among children in kindergartens and public schools in Kuwait, and determine their need for dental health care, 2) to describe changes in caries prevalence and experience from 1982 to 1993 and 3) to provide a baseline for the evaluation of the preventive oral health programmes starting in Kuwait in 1994. The study population comprised 3,500 4-, 6-, 12- and 15-year-old children in kindergartens and public schools in Kuwait, selected by stratified cluster sampling. Dental caries was scored by surface in accordance with WHO criteria, and dental fluorosis was registered by Dean's index (modified). The mean deft was 4.6 at age 4 years, and 6.2 at age 6; 8 and 11 percent of the decay had been treated by extractions or fillings in the two respective age groups. Among the 6-, 12- and 15-year-old children DMFT was 0.2, 2.6 and 3.6 respectively; 12 and 14 percent of the decayed teeth of 12- and 15-year-old children had been treated. As to the 4- and 6-year-old children, 19 and 9 percent were caries-free in the deciduous teeth, while 86, 21 and 14 percent of the 6-, 12- and 15-year-old children were caries-free in the permanent teeth. Among the 4-year-old children 47 percent had caries in the front teeth. None of the children had severe dental fluorosis, but 6 percent at 12 and 15 years showed mild to moderate, but manifest, dental fluorosis. The survey revealed that caries experience as well as caries prevalence had increased since 1982, although there was a marked increase in the number of filled tooth surfaces in all age cohorts. However, in 1993 the DMFT of 12-year-old children was still well within WHO's global goal for the year 2000, whereas the prevalence of dental caries among 6-year-old was considerably higher than the WHO goal.

Oral health status and treatment needs of pregnant women in Lagos State.

PubMed

Agbelusi, G A; Akinwande, J A; Shutti, Y O

2000-09-01

The oral health status and treatment needs of 250 pregnant women attending the antenatal clinic at Randle Health Centre was investigated. A coded questionnaire was administered to the pregnant women followed by their oral examination in the dental clinic. The mean oral hygiene index score increased progressively throughout pregnancy viz 1st trimester 0.72, second trimester 1.06 and third trimester 1.23. Community Periodontal Index of Treatment Needs (CPITN) revealed that 50% required scale and polish and oral hygiene instruction, 13.60% required oral hygiene instruction only and 32.2% did not require any treatment. Decayed Missing and Filled (DMF) recorded was 1.54. 51.72% of the pregnant women required amalgam fillings, 23.27% required extraction due to caries and 16.38% required partial dentures.

Cytotoxic evaluation of hydroxyapatite-filled and silica/hydroxyapatite-filled acrylate-based restorative composite resins: An in vitro study.

PubMed

Chadda, Harshita; Naveen, Sangeetha Vasudevaraj; Mohan, Saktiswaren; Satapathy, Bhabani K; Ray, Alok R; Kamarul, Tunku

2016-07-01

Although the physical and mechanical properties of hydroxyapatite-filled dental restorative composite resins have been examined, the biocompatibility of these materials has not been studied in detail. The purpose of this in vitro study was to analyze the toxicity of acrylate-based restorative composite resins filled with hydroxyapatite and a silica/hydroxyapatite combination. Five different restorative materials based on bisphenol A-glycidyl methacrylate (bis-GMA) and tri-ethylene glycol dimethacrylate (TEGDMA) were developed: unfilled (H0), hydroxyapatite-filled (H30, H50), and silica/hydroxyapatite-filled (SH30, SH50) composite resins. These were tested for in vitro cytotoxicity by using human bone marrow mesenchymal stromal cells. Surface morphology, elemental composition, and functional groups were determined by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier-transformed infrared spectroscopy (FTIR). The spectra normalization, baseline corrections, and peak integration were carried out by OPUS v4.0 software. Both in vitro cytotoxicity results and SEM analysis indicated that the composite resins developed were nontoxic and supported cell adherence. Elemental analysis with EDX revealed the presence of carbon, oxygen, calcium, silicon, and gold, while the presence of methacrylate, hydroxyl, and methylene functional groups was confirmed through FTIR analysis. The characterization and compatibility studies showed that these hydroxyapatite-filled and silica/hydroxyapatite-filled bis-GMA/TEGDMA-based restorative composite resins are nontoxic to human bone marrow mesenchymal stromal cells and show a favorable biologic response, making them potential biomaterials. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Methods used by accredited dental specialty programs to advertise faculty positions: results of a national survey.

PubMed

Ballard, Richard W; Hagan, Joseph L; Armbruster, Paul C; Gallo, John R

2011-01-01

The various reasons for the current and projected shortages of dental faculty members in the United States have received much attention. Dental school deans have reported that the top three factors impacting their ability to fill faculty positions are meeting the requirements of the position, lack of response to position announcement, and salary/budget limitations. An electronic survey sent to program directors of specialty programs at all accredited U.S. dental schools inquired about the number of vacant positions, advertised vacant positions, reasons for not advertising, selection of advertising medium, results of advertising, and assistance from professional dental organizations. A total of seventy-three permanently funded full-time faculty positions were reported vacant, with 89.0 percent of these positions having been advertised in nationally recognized professional journals and newsletters. Networking or word-of-mouth was reported as the most successful method for advertising. The majority of those responding reported that professional dental organizations did not help with filling vacant faculty positions, but that they would utilize the American Dental Association's website or their specialty organization's website to post faculty positions if they were easy to use and update.

Planning oral health and clinical discharge in primary care: the comprehensive dental care protocol outcome.

PubMed

Cavalcanti, Yuri Wanderley; Dantas de Almeida, Leopoldina de Fátima; Barbosa, Ailma de Souza; Nascimento Padilha, Wilton Wilney

2015-03-01

The dental care must be driven by preventive and curative measures that can contribute to the population's oral health promotion. To evaluate the impact of the actions proposed by a comprehensive dental care protocol (CDCP) on the oral health condition of primary care users. The sample consisted of 32 volunteers, assisted throughout the six phases proposed by the CDCP: diagnosis of dental needs; resolution of urgencies; restorative interventions; application of promotional measures; evaluation of the achieved health level; and periodic controls. Data were collected through clinical exams, which measured the simplified oral hygiene index (OHI-S), gingival bleeding index (GBI) and the decayed, missing and filled teeth (DMFT) Index, before and after the CDCP was implemented. Statistical analysis consisted of the Wilcoxon test, at 5% significance level (α = 0.05). The OHI-S and GBI indices showed a significant reduction (p < 0.05) from the initial (1.4 ± 0.6 and 46.3 ± 19.9) to final condition (0.9 ± 0.3 and 21.5 ± 7.5). The decayed, missing and filled teeth and the missing teeth component were not significantly altered (p > 0.05), showing final values equal to 12.7 ± 9.6 and 5.6 ± 7.8, respectively. Decayed elements were fully converted into filled elements, and the final values of the decayed and filled elements were, respectively, 0.0 ± 0.0 and 7.3 ± 5.7 (p < 0.05). The enactment of the CDCP had a beneficial effect on the oral health of the population assisted by the dental services offered in primary care and this protocol seems to ft the public dental service demands. The CDCP can be useful to public dental service planning since it showed an efficient clinical outcome to the patients. We consider that this protocol should be employed in primary care oral health services in order to achieve overall upgrade, access enlargement and public oral health promotion.

The role of dental hygiene in caries management: a new paradigm.

PubMed

Young, Douglas A; Lyon, Lucinda; Azevedo, Shelly

2010-01-01

Dental caries is the most common disease of children and remains a significant oral health problem worldwide for both children and adults. The traditional paradigm of treating dental caries solely by "drilling and filling," brushing and flossing and lowering sugar intake has evolved. Current science in the management of dental caries suggests a clear focus on the reduction of responsible infectious agents, remineralization of non-cavitated lesions and minimally invasive restorative approaches whenever possible. The paradigm shift is away from a purely surgical approach toward more preventive and curative clinical protocols. This paper provides a review of this caries management methodology and explores the role of the dental hygienist in this paradigm change.

Influence of the usual motivation for dental attendance on dental status and oral health-related quality of life.

PubMed

Montero, Javier; Albaladejo, Alberto; Zalba, José-Ignacio

2014-05-01

To evaluate the influence of dental visiting patterns on the dental status and Oral Health-related Quality of Life (OHQoL) of patients visiting the University Clinic of Salamanca (Spain). This cross-sectional study consisted of a clinical oral examination and a questionnaire-based interviewin a consecutive sample of patients seeking a dental examination. Patients were classified as problem-based dental attendees(PB) and regular dental attendees(RB). Clinical and OHQoL(OHIP-14 & OIDP)data were compared betweengroups. Pair-wise comparisons were performed and a Logistic Regression Model was fitted for predicting the Odds Ratio (OR) of being a PB patient. The sample was composed of 255 patients aged 18 to 87 years (mean age: 63.1 ± 12.7; women: 51.8%). The PB patients had a poorer dental status (i.e. caries, periodontal and prosthetic needs), brushed their teethless,and were significantly more impaired in their OHQoL according to both instruments.The logistic regression coefficients demonstrated that on average the OR of being a PB patient was high in this dental patient sample, but this OR increased significantly if the patient was a male (OR= 1.1-5.0) or referred pain-related impacts according to the OHIP and, additionally, the OR decreased significantly as a function of the number of healthy fillings and the number of sextants coded as CPI=0. Regular dental check-ups are associated with better dental status and a better OHQoL after controlling for potentially related confounding factors.

SPECT/CT localization of oral radioiodine activity: a retrospective study and in-vitro assessment.

PubMed

Burlison, Jared S; Hartshorne, Michael F; Voda, Alan M; Cocks, Franklin H; Fair, Joanna R

2013-12-01

We sought to further localize radioiodine activity in the mouth on post-thyroid cancer therapy imaging using single-photon emission computed tomography/computed tomography (SPECT/CT). We retrospectively reviewed all patients (58) who underwent thyroid cancer therapy with iodine-131 (131I) at our institution from August 2009 to March 2011 whose post-therapy radioiodine imaging included neck SPECT/CT. A small group (six) of diagnostic 131I scans including SPECT/CT was also reviewed. Separately, we performed in-vitro 131I (sodium iodide) binding assays with amalgam and Argenco HP 77 (77% dental gold alloy) as proof of principle for these interactions. Of the 58 post-therapy patients, 45 (78%) had undergone metallic dental restorations, and of them 41 (91%) demonstrated oral 131I activity localizing preferentially to those restorations. It was observed that radioiodine also localized to other dental restorations and to orthodontic hardware. Gum-line activity in edentulous patients suggests radioiodine interaction with denture adhesive. In vitro, dental amalgam and Argenco HP 77 bound 131I in a time-dependent manner over 1-16 days of exposure. Despite subsequent washings with normal saline, significant 131I activity (maximally 12% for amalgam and 68% for Argenco HP 77) was retained by these metals. Subsequent soaking in a saturated solution of potassium iodide partially displaced 131I from amalgam, with near-total displacement of I from Argenco HP 77. SPECT/CT shows that radioiodine in the oral cavity localizes to metallic dental restorations. Furthermore, in-vitro studies demonstrate partially reversible binding of 131I to common dental metals.

Dental caries experience and treatment needs of an adult female population in Nigeria.

PubMed

Lawal, Folake; Alade, Omolola

2017-09-01

Experience and awareness of adult females concerning dental caries is important in its prevention particularly in children because of their natural role as care givers. To determine the prevalence of dental caries and treatment needs in an adult female Nigerian population. In this cross-sectional study, adult females attending outreach programmes were examined for dental caries using the Decayed Missing and Filled Teeth caries index (DMFT). Socio-demographic variables were also recorded and statistical analysis done with SPSS software. A total of 430 females aged 16 to 59 years participated in the outreach programme out of which 109 (25.3%) had a DMFT score > 0. Mean DMFT was 0.7 ± 1.6. Fifty-five (12.8%) participants had decayed teeth, 78 (18.1 %) had missing teeth and 10(2.3%) had filled teeth. The treatment need was 34.3%, restorative index was 13.3% and significant caries index was 2.0. There were significant differences in caries experience based on age, marital status and educational qualifications of participants p < 0.05. The prevalence of dental caries among the study group was low but the treatment need was high. Younger females, singles and those with lower educational qualifications had a higher dental caries experience.

Correlation of gingival thickness with gingival width, probing depth, and papillary fill in maxillary anterior teeth in students of a dental college in Navi Mumbai

PubMed Central

Singh, Jyotsna; Rathod, Varsha J.; Rao, Prajakta R.; Patil, Aardra A.; Langade, Deepak G.; Singh, Roshan K.

2016-01-01

Context: The gingival biotype is of utmost importance for esthetics and biologic function. Anatomical characteristic of periodontium such as gingival thickness (GT), width of keratinized gingiva, and alveolar bone morphology will determine the behavior of periodontium when subjected to physical, chemical, or bacterial insult or during therapeutic procedure. Aims: The aim of this study was to correlate the GT with gingival width (GW), probing depth (PD), and papillary fill (PF) in relation to maxillary anterior region. Settings and Design: Undergraduate dental students and interns from a dental college in Navi Mumbai were enrolled in the study according to the inclusion criteria. Six teeth per subject were assessed; a total of 2178 maxillary anterior teeth were examined. Subjects and Methods: Subjects were examined clinically for GT, width of keratinized gingiva, pocket depth, and interdental PF. The data obtained was tabulated and subjected to statistical analysis. Statistical Analysis Used: Spearman's correlation analysis test was performed to find the correlation of GT with GW, PD, and PF. Results: Positive correlation was found between GT and GW (r = 0.241). No significant correlation could be found between GT and PD; and between GT and PF. Conclusions: The present study confirmed a positive correlation between GT and GW. A weak negative correlation was found between GT and PD. PMID:27994424

Correlation of gingival thickness with gingival width, probing depth, and papillary fill in maxillary anterior teeth in students of a dental college in Navi Mumbai.

PubMed

Singh, Jyotsna; Rathod, Varsha J; Rao, Prajakta R; Patil, Aardra A; Langade, Deepak G; Singh, Roshan K

2016-01-01

The gingival biotype is of utmost importance for esthetics and biologic function. Anatomical characteristic of periodontium such as gingival thickness (GT), width of keratinized gingiva, and alveolar bone morphology will determine the behavior of periodontium when subjected to physical, chemical, or bacterial insult or during therapeutic procedure. The aim of this study was to correlate the GT with gingival width (GW), probing depth (PD), and papillary fill (PF) in relation to maxillary anterior region. Undergraduate dental students and interns from a dental college in Navi Mumbai were enrolled in the study according to the inclusion criteria. Six teeth per subject were assessed; a total of 2178 maxillary anterior teeth were examined. Subjects were examined clinically for GT, width of keratinized gingiva, pocket depth, and interdental PF. The data obtained was tabulated and subjected to statistical analysis. Spearman's correlation analysis test was performed to find the correlation of GT with GW, PD, and PF. Positive correlation was found between GT and GW ( r = 0.241). No significant correlation could be found between GT and PD; and between GT and PF. The present study confirmed a positive correlation between GT and GW. A weak negative correlation was found between GT and PD.

Failure behavior of glass ionomer cement under Hertzian indentation.

PubMed

Wang, Yan; Darvell, B W

2008-09-01

To investigate the load-bearing capacity and failure mode of various types of glass ionomer cement (GIC) under Hertzian indentation, exploring the relationship between the failure behavior and formulation, and examining claims of filler-reinforcement of GIC. Discs 2mm thick, 10mm diameter, 8-18 replicates, were fabricated for two filler-reinforced GICs, four unmodified and unreinforced GICs, and four resin-modified GICs, with a dental silver amalgam and a filled-resin restorative material for comparison. Testing was at 23 degrees C, wet, after 7d storage at 37 degrees C in artificial saliva at pH 6, using a 20mm diameter hard steel ball and filled-nylon substrate (E: 10GPa). First failure was detected acoustically; mode was determined visually. At least 1/3 of specimens in each case were examined under scanning electronic microscope for corroboration. Reinforced and unmodified-unreinforced GICs were indistinguishable by failure load (one-way analysis of variance, P=0.425, overall 260+/-70N) and mode. Failure loads for resin-modified GICs were 360-1150N, amalgam approximately 680N, and filled resin approximately 1200N. Resin-modified GICs tended to be tougher (incomplete fracture), all others gave complete fracture (radial cracking). The stronger materials (two resin-modified GICs and filled resin) showed some cone cracking. While resin-modified GICs showed various extents of increase of failure load over that of the plain GICs, consistent with the hybrid chemistry, filler-reinforcement was not evident for the two claimed products, consistent with structural and theoretical expectations.

Mercury contamination - Amalgamate (contract with NFS and ADA). Stabilize Elemental Mercury Wastes. Mixed Waste Focus Area. OST Reference Number 1675

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

1999-09-01

Through efforts led by the Mixed Waste Focus Area (MWFA) and its Mercury Working Group (HgWG), the inventory of bulk elemental mercury contaminated with radionuclides stored at various U. S. Department of Energy (DOE) sites is thought to be approximately 16 m3 (Conley et al. 1998). At least 19 different DOE sites have this type of mixed low-level waste in their storage facilities. The U. S. Environmental Protection Agency (EPA) specifies amalgamation as the treatment method for radioactively contaminated elemental mercury. Although the chemistry of amalgamation is well known, the practical engineering of a sizable amalgamation process has not beenmore » tested (Tyson 1993). To eliminate the existing DOE inventory in a reasonable timeframe, scaleable equipment is needed that can: produce waste forms that meet the EPA definition of amalgamation, produce waste forms that pass the EPA Toxicity Characteristic Leaching Procedure (TCLP) limit of 0.20 mg/L, limit mercury vapor concentrations during processing to below the Occupational Safety and Health Administration’s (OSHA) 8-hour worker exposure limit (50 mg/m3) for mercury, and perform the above economically.« less

Insights into ergonomics among dental professionals of a dental institute and private practitioners in hubli-dharwad twin cities, India.

PubMed

Kalghatgi, Shrivardhan; Prasad, Kakarla Veera Venkata; Chhabra, Kumar Gaurav; Deolia, Shravani; Chhabra, Chaya

2014-12-01

To assess the knowledge, attitude, and practice of ergonomics among dental professionals of Hubli-Dharwad twin cities, India. Investigator-developed, self-administered, closed-ended questionnaire assessing knowledge, attitude, and practices regarding ergonomics during dental practice was filled in by undergraduates, house surgeons, postgraduates, and faculty members of dental institutions and private practitioners from Hubli-Dharwad twin cities. Data were collected from a total of 250 participants, 50 belonging to each academic group. Overall mean knowledge, attitude, and practice scores were 52%, 75%, and 55%, respectively. Significant correlation was found for age with attitude (χ(2) = 10.734, p = 0.030) and behavior (χ(2) = 12.984, p = 0.011). Marital status was significantly associated with all the three domains; knowledge (χ(2) = 29.369, p = 0.000), attitude (χ(2) = 29.023, p = 0.000), and practices (χ(2) = 13.648, p = 0.009). Participants had considerable awareness and behavior toward ergonomics in dental practice. The high attitude score indicates stronger acceptance of ergonomics principles and guidelines during routine dental procedures. The current study highlights the situation of ergonomics in dental practice in the form of knowledge, attitude, and practices.

Allergic rhinitis and dental caries in preschool children

PubMed Central

Bakhshaee, Mehdi; Ashtiani, Sara Jafari; Hossainzadeh, Mana; Sehatbakhsh, Samineh; Najafi, Mona Najaf; Salehi, Maryam

2017-01-01

Background: Allergic rhinitis (AR) may be overdocumented in cases of dental caries because of controversies in the literature This study was conducted to investigate the potential relationship between AR and dental caries in children. Materials and Methods: A total of 296 children were included in this cross-sectional study. Participants were evaluated using the decay-missing-filled (DMF) index, and their AR status was evaluated by physical examination and through a standard questionnaire. Baseline demographics and clinical characteristics were compared among groups using Student's t-test or the Mann–Whitney U-test, the Chi-square test, and/or Fisher's exact test as appropriate. A level of P < 0.05 was regarded as statistically significant. Results: Evidence of AR was found in 77 (35.1%) participants. There was no significant difference in the rate of tooth decay or DMF between participants with or without AR (P = 0.07), but a significant difference was observed in the number of missing and filled teeth between those with and without AR (P < 0.05). There were no significant differences in educational level, family income, milk intake, use of pacifier, use of a toothbrush, saliva secretion, or body mass index (P > 0.05 in all cases) between AR-positive and AR-negative patients. Fluoride therapy and oral breathing were identified as confounding factors and controlled using log-linear analysis. The mean rate of DMF in patients who also had AR was 20% greater than in the AR-negative group (odds ratio [OR] = 1.21, confidence interval [CI]: 1.05–1.35) and 15% greater in among children who breathed orally than those who did not (OR = 1.15 CI: 1.02–1.31). Conclusion: AR and oral breathing may have an effect on oral health and dental condition, leading to an increased rate of tooth loss, oral fillings, and development of dental caries. PMID:29238375

Thermal diffusion through amalgam and cement base: comparison of in vitro and in vivo measurements.

PubMed

Tibbetts, V R; Schnell, R J; Swartz, M L; Phillips, R W

1976-01-01

Thermal diffusion was measured in vitro and in vivo through amalgam and amalgam underlaid with bases of zinc phosphate, zinc oxide-eugenol, and calcium hydroxide cements. Although the magnitudes differed, there generally was good agreement between in vitro and in vivo data with respect to the relative rates of thermal diffusivity through amalgam restorations underlaid with bases of each of the three materials. In all tests, both in vitro and in vivo, the zinc oxide-eugenol base proved to be the best thermal insulator. Calcium hydroxide was the next best thermal barrier and was followed by zinc phosphate cement. In vitro tests indicated dentin to be a better thermal insulator than zinc phosphate cement but inferior to the zinc oxide-eugenol and calcium hydroxide base materials used here. Although a method has been presented here for the in vivo assessment of the efficacy of thermal insulating bases and a number of in vivo experiments were conducted, much research remains to be done in this area. Additional investigation is needed to better define the parameters of thermal change beneath various types of restoratives and also to establish more exactly the role of base thickness in providing thermal protection beneath clinical metallic restorations.

Synthetic Light-Curable Polymeric Materials Provide a Supportive Niche for Dental Pulp Stem Cells.

PubMed

Vining, Kyle H; Scherba, Jacob C; Bever, Alaina M; Alexander, Morgan R; Celiz, Adam D; Mooney, David J

2018-01-01

Dental disease annually affects billions of patients, and while regenerative dentistry aims to heal dental tissue after injury, existing polymeric restorative materials, or fillings, do not directly participate in the healing process in a bioinstructive manner. There is a need for restorative materials that can support native functions of dental pulp stem cells (DPSCs), which are capable of regenerating dentin. A polymer microarray formed from commercially available monomers to rapidly identify materials that support DPSC adhesion is used. Based on these findings, thiol-ene chemistry is employed to achieve rapid light-curing and minimize residual monomer of the lead materials. Several triacrylate bulk polymers support DPSC adhesion, proliferation, and differentiation in vitro, and exhibit stiffness and tensile strength similar to existing dental materials. Conversely, materials composed of a trimethacrylate monomer or bisphenol A glycidyl methacrylate, which is a monomer standard in dental materials, do not support stem cell adhesion and negatively impact matrix and signaling pathways. Furthermore, thiol-ene polymerized triacrylates are used as permanent filling materials at the dentin-pulp interface in direct contact with irreversibly injured pulp tissue. These novel triacrylate-based biomaterials have potential to enable novel regenerative dental therapies in the clinic by both restoring teeth and providing a supportive niche for DPSCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dental caries and preterm birth: a systematic review and meta-analysis

PubMed Central

D’Antonio, Francesco; Reierth, Eirik; Basnet, Purusotam; Trovik, Tordis A; Orsini, Giovanna; Manzoli, Lamberto; Acharya, Ganesh

2018-01-01

Objectives The primary objective of this systematic review was to evaluate the association between dental caries and preterm birth (PTB). The secondary objective was ascertaining the difference between women with dental caries who experienced PTB and those who did not with regard to decayed, missing and filled teeth (DMFT), and decayed, missing and filled surfaces (DMFS) indices. Methods MEDLINE, Embase, CINAHL and Cochrane databases were searched initially in November 2015 and repeated in December 2016. We included observational cohort and case–control studies. Only studies reporting the risk of PTB in women affected compared with those not affected by dental caries in pregnancy were included. Random-effect meta-analyses were used to compute the summary OR of PTB among women with caries versus women without caries, and the mean difference in either DMFT or DMFS indices between women experiencing PTB and those without PTB. Results Nine observational studies (4826 pregnancies) were included. Women affected by dental caries during pregnancy did not show a significantly higher risk of PTB (OR: 1.16, 95% CI 0.90 to 1.49, P=0.25, I2=35%). Also, the women with PTB did not show significantly higher DMFT or DMFS indices (summary mean differences: 1.56, P=0.10; I2=92% and −0.15, P=0.9, I2=89%, respectively). Conclusion Dental caries does not appear to be a substantial risk factor for PTB. Trial registration number NCT01675180; Pre-results. PMID:29500202

Prevalence of dental caries among 12–14 year old children in Qatar

PubMed Central

Al-Darwish, Mohammed; El Ansari, Walid; Bener, Abdulbari

2014-01-01

Background To ensure the oral health of a population, clinicians must deliver appropriate dental services, and local communities need to have access to dental care facilities. However, establishment of this infrastructure must be based on reliable information regarding disease prevalence and severity in the target population. Objectives The aims of this study were to measure the incidence of dental caries in school children aged 12–14 throughout Qatar, including the influence of socio-demographic factors. Materials and methods A cross-sectional study was conducted in Qatar from October 2011 to March 2012. A total of 2113 children aged 12–14 were randomly selected from 16 schools located in different geographic areas. Three calibrated examiners using World Health Organization (WHO) criteria to diagnose dental caries performed the clinical examinations. Data analyses were subsequently conducted. Results The mean decayed, missing, and filled teeth index values were respectively 4.62 (±3.2), 4.79 (±3.5), and 5.5 (±3.7), for 12, 13, and 14 year-old subjects. Caries prevalence was 85%. The mandibular incisors and canines were least affected by dental caries, while maxillary and mandibular molars exhibited the highest incidence of dental caries. Dental caries were affected by socio-demographic factors; significant differences were detected between female and male children, where more female children showed dental caries than male children. In addition, children residing in semi-urban areas showed more dental caries than in urban areas. Conclusion Results indicated that dental caries prevalence among school children in Qatar has reached critical levels, and is influenced by socio-demographic factors. The mean decayed, missing, and filled teeth values obtained in this study were the second highest detected in the Eastern Mediterranean region. PMID:25057232

Dental pain and associated factors among pregnant women: an observational study.

PubMed

Krüger, Marta S M; Lang, Celina A; Almeida, Luiza H S; Bello-Corrêa, Fernanda O; Romano, Ana R; Pappen, Fernanda G

2015-03-01

The present study aimed to determine the prevalence of dental pain during pregnancy and its association with sociodemographic factors and oral health conditions among 315 pregnant women in South Brazil. Participants were interviewed to obtain sociodemographic data, such as age, educational level, employment status, family income, and marital and parity status. Medical and dental histories were also collected, including the occurrence of dental pain and the use of dental services during pregnancy. Clinical examinations were performed to assess the presence of visible plaque and gingival bleeding and to calculate the decayed, missing, and filled teeth index. Means and standard deviations of continuous variables and frequencies and percentages of categorical variables were calculated. Independent variables were included in a multivariate logistic regression analysis. A total of 173 (54.9 %) pregnant women reported dental pain during pregnancy. After adjustment of the analysis, caries activity remained the main determinant of dental pain (odds ratio 3.33, 95 % CI 1.67-6.65). The prevalence of dental pain during pregnancy was high and the presence of caries activity was a determinant of dental pain. Moreover, access to oral health care was low, despite pregnant women's increased need for dental assistance.

Dental health status in crack/cocaine-addicted men: a cross-sectional study.

PubMed

Cury, Patricia R; Oliveira, Maria G A; de Andrade, Katia Montanha; de Freitas, Maíra D S; Dos Santos, Jean N

2017-03-01

The aim of this study was to evaluate the association between crack/cocaine addiction and dental health in men. Forty crack/cocaine-addicted patients and 120 nonaddicted patients (≥18 years) underwent full-mouth dental examinations. Decayed, missing, and filled teeth (DMFT) were identified using the criteria recommended by the World Health Organization. Crack/cocaine addiction was determined, based on the medical records and interviews of each patient. All drug-addicted patients used both crack and cocaine. The chi-square test and logistic regression analysis were used to assess the association between DMFT and crack/cocaine addiction (p ≤ 0.05). Decayed teeth showed a positive association with crack/cocaine addiction (odds ratio (OR) = 3.65; 95% confidence interval (CI), 1.68-7.92; p = 0.001), whereas filled and missing teeth showed a negative association (filled teeth: OR = 0.37; 95% CI, 0.18-0.76; p = 0.008; missing teeth: OR = 0.33; 95% CI, 0.13-0.81; p = 0.02). The DMFT was only associated with age (OR = 2.12; 95% CI, 1.11-4.08, p = 0.023). In the present population, crack/cocaine addiction was associated with a greater decayed teeth index and a lower filled and missing teeth index. Programs aimed to encourage self-esteem and encourage individuals to seek dental care are required for this population. Further studies using a larger sample size and studies with women are required to confirm the results.

Understanding the management and teaching of dental restoration repair: Systematic review and meta-analysis of surveys.

PubMed

Kanzow, Philipp; Wiegand, Annette; Göstemeyer, Gerd; Schwendicke, Falk

2018-02-01

Repair instead of complete replacement is recommended to manage partially defective restorations. It is unclear if and why such treatment is taught at dental schools or practiced by dentists. We aimed to identify barriers and facilitators for repairs using a systematic review and meta- and qualitative analysis. Electronic databases (PubMed, CENTRAL, Embase, PsycINFO) were searched. Quantitative studies reporting on the proportion of (1) dentists stating to perform repairs, (2) dental schools teaching repairs, (3) failed restorations having been repaired were included. We also included qualitative studies on barriers/facilitators for repairs. Random-effects meta-analyses, meta-regression and a thematic analysis using the theoretical domains framework were conducted. 401 articles were assessed and 29, mainly quantitative, studies included. 7228 dentists and 276 dental schools had been surveyed, and treatment data of 30,172 restorations evaluated. The mean (95% CI) proportion of dentists stating to perform repairs was 71.5% (49.7-86.4%). 83.3% (73.6-90.0%) of dental schools taught repairs. 31.3% (26.3-36.7%) of failed restorations had been repaired. More recent studies reported significantly more dentists to repair restorations (p=0.004). Employment in public health practices and being the dentist who placed the original restoration were facilitators for repairs. Amalgam restorations were repaired less often, and financial aspects and regulations came as barriers. While most dentists state to perform repairs and the vast majority of dental schools teach repairs, the proportion of truly repaired restorations was low. A number of interventions to implement repair in dental practice can be deduced from our findings. Partially defective restorations are common in dental practice. While repairs are taught and dentists are aware of the recommendation towards repairs, the actually performed proportion of repairs seems low. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessing dental caries prevalence in African-American youth and adults.

PubMed

Seibert, Wilda; Farmer-Dixon, Cherae; Bolden, Theodore E; Stewart, James H

2004-01-01

It has been well documented that dental caries affect millions of children in the USA with the majority experiencing decay by the late teens. This is especially true for low-income minorities. The objective of this descriptive study was to determine dental caries prevalence in a sample of low-income African-American youth and adults. A total of 1034 individuals were examined. They were divided into two age groups: youth, 9-19 years and adults, 20-39 years. Females comprised approximately 65 percent (64.5) of the study group. The DMFT Index was used to determine caries prevalence in this study population. The DMFT findings showed that approximately 73 percent (72.9 percent) of the youth had either decayed, missing or filled teeth. Male youth had slightly higher DMFT mean scores than female youth: male mean = 7.93, standard error = 0.77, female mean = 7.52, standard error = 0.36; however, as females reached adulthood their DMFT scores increased substantially, mean = 15.18, standard error = 0.36. Caries prevalence was much lower in male adults, DMFT, mean = 7.22, standard error of 0.33. The decayed component for female adults mean score was 6.81, a slight increase over adult males, mean = 6.58. Although there were few filled teeth in both age groups, female adults had slightly more filled teeth than male adults, females mean = 2.91 vs. males; however, adult males experienced slightly more missing teeth, mean = 5.62 as compared to adult females, mean = 5.46. n = 2.20. Both female and male adults had an increase in missing teeth. As age increased there was a significant correlation among decayed, missing and filled teeth as tested by Analysis of Variance (ANOVA), p < 0.01. A significant correlation was found between filled teeth by sex, p < .005. We conclude that caries prevalence was higher in female and male youth, but dental caries increased more rapidly in females as they reached adulthood.

Survival of Fuji IX ART fillings in permanent teeth of primary school children in Tanzania.

PubMed

Kikwilu, E N; Mandari, G J; Honkala, E

2001-08-01

To evaluate the clinical performance of atraumatic restorative treatment (ART) fillings using Fuji IX as a filling material in field conditions. Longitudinal study of the ART fillings in permanent teeth of primary school children aged eight to fifteen years. Primary schools in Morogoro municipality, Tanzania. Standard 3 and 4 children in five primary schools randomly selected from a list of 36 primary schools of Morogoro municipality were examined for dental caries and periodontal conditions. All 296 carious lesions that were indicated for restoration were treated using ART approach according to the instructions given in the manual for ART approach for the control of dental caries. Essential measurements for treated teeth and cavity were taken. The cavities were filled with Fuji IX glass ionomer cement as per manufacturer's instructions. After one year, 238 restorations were evaluated using the criteria for evaluating ART restorations. Clinical appearance of the surface of the restorations. Ninety four per cent of the restorations evaluated were rated as good and intact, while 1.7% were rated as having slight defects that needed no repair, giving a one year survival rate of 96.1%. Mean working time was 14.5 minutes. The one-year survival rate of 96.1% is high enough to recommend wide use of ART in Tanzania. Town and municipal councils should be encouraged to adopt ART in their school oral health programmes.

Ten years on: Is dental general anaesthesia in childhood a risk factor for caries and anxiety?

PubMed Central

Haworth, S.; Dudding, T.; Waylen, A.; Thomas, S. J.; Timpson, N. J.

2017-01-01

Objectives To identify whether dental general anaesthesia (DGA) status is informative in assessing risk of caries or dental anxiety by (a) describing long-term oral health and dental anxiety for people who underwent DGA in childhood and (b) testing whether DGA status in childhood is associated with incident future dental caries or anxiety independently of preconceived risk factors. Design Analysis of prospectively obtained data. Setting An established population based cohort in the UK, the Avon Longitudinal Study of Parents and Children. Participants and methods In total 1,695 participants with dental data in childhood and adolescence were included in analysis. DGA status by age 7 and oral health measures at age 17 were identified from questionnaire data. Main outcome measures Filled or extracted permanent teeth at age 17, Corah Dental Anxiety Scale. Results One hundred and twenty-eight (7.6%) participants underwent DGA in childhood. Individuals who underwent DGA had higher measures of filled or extracted permanent teeth in adolescence (0.36 more affected teeth in fully-adjusted model [95% confidence interval: 0.27, 0.55; P <0.001]). Conclusions DGA in childhood predicts burden of treated caries in adolescence, independently of other risk factors. DGA status may be a clinically useful adjunct in identifying young people at high risk of further disease. PMID:28232699

Ten years on: Is dental general anaesthesia in childhood a risk factor for caries and anxiety?

PubMed

Haworth, S; Dudding, T; Waylen, A; Thomas, S J; Timpson, N J

2017-02-24

Objectives To identify whether dental general anaesthesia (DGA) status is informative in assessing risk of caries or dental anxiety by (a) describing long-term oral health and dental anxiety for people who underwent DGA in childhood and (b) testing whether DGA status in childhood is associated with incident future dental caries or anxiety independently of preconceived risk factors.Design Analysis of prospectively obtained data.Setting An established population based cohort in the UK, the Avon Longitudinal Study of Parents and Children.Participants and methods In total 1,695 participants with dental data in childhood and adolescence were included in analysis. DGA status by age 7 and oral health measures at age 17 were identified from questionnaire data.Main outcome measures Filled or extracted permanent teeth at age 17, Corah Dental Anxiety Scale.Results One hundred and twenty-eight (7.6%) participants underwent DGA in childhood. Individuals who underwent DGA had higher measures of filled or extracted permanent teeth in adolescence (0.36 more affected teeth in fully-adjusted model [95% confidence interval: 0.27, 0.55; P <0.001]).Conclusions DGA in childhood predicts burden of treated caries in adolescence, independently of other risk factors. DGA status may be a clinically useful adjunct in identifying young people at high risk of further disease.

Meth mouth severity in response to drug-use patterns and dental access in methamphetamine users.

PubMed

Brown, Ronni E; Morisky, Donald E; Silverstein, Steven J

2013-06-01

Meth mouth is the rapid development of tooth decay in methamphetamine users. Our study questioned whether drug-use patterns and dental care access are risk factors affecting the severity of meth mouth. Participants received dental examinations, and the number of decayed, missing and filled teeth (DMFT) were counted and used to measure meth mouth severity.

2. FOURTH FLOOR VIEW TO NORTHEAST, WITH I.J. STOKES DENTAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. FOURTH FLOOR VIEW TO NORTHEAST, WITH I.J. STOKES DENTAL POWDER FILLING MACHINE (CENTER) AND PACKING TABLE (LEFT CENTER) - Colgate & Company Jersey City Plant, G Block, 81-95 Greene Street, Jersey City, Hudson County, NJ

Impact of dental pain on daily living of five-year-old Brazilian preschool children: prevalence and associated factors.

PubMed

Moure-Leite, F R; Ramos-Jorge, J; Ramos-Jorge, M L; Paiva, S M; Vale, M P; Pordeus, I A

2011-12-01

To assess the impact of dental pain on the daily living of 5-year-old preschool children using reports from parents/guardians. A cross-sectional study was carried out involving 549 five-year-old children randomly selected from preschools in the city of Belo Horizonte, Brazil. Data were collected using a previously validated parent-reported questionnaire. The children received dental examinations from a single calibrated examiner. The following outcome variables were selected: age, gender, dental caries, filled teeth, missing teeth, caries involving pulp and social class. Simple and multiple logistic regression analyses were performed on the data. According to parents' reports, 11.1% of children were affected by dental pain in the previous 4 months and of these 72.6% had their daily activities hampered by pain. The majority of these children had difficulty in eating, brushing teeth, sleeping, playing and going to school. The impact of dental pain had a statistically significant association with gender (p=0.001), social class (p=0.009), dental caries (p<0.001), missing teeth (p<0.001), filled teeth (p<0.001) and caries involving pulp (p<0.001). The prevalence of difficulties performing tasks of daily living due to dental pain was relatively high among the children studied.

[Dental caries and early childhood development: a pilot study].

PubMed

Núñez, F Loreto; Sanz, B Javier; Mejía, L Gloria

2015-01-01

To investigate the association between dental caries and early childhood development in 3-year-olds from Talca, Chile. A pilot study with a convenience sample of 3-year-olds from Talca (n = 39) who attend public healthcare centers. Child development was measured by the Psychomotor Development Index (PDI), a screening tool used nationally among pre-school children to assess language development, fine motor skills and coordination areas. Dental caries prevalence was evaluated by decayed, missing, filled teeth (DFMT) and decayed, missing, filled tooth surfaces (DFMS) ceo-d and ceo-s indexes. The children were divided into two groups according to the PDIscore: those with a score of 40 or more were considered developmentally normal (n = 32), and those with a score below 40 were considered as having impaired development (n = 7). The severity of caries (DMFT) was negatively correlated with PDI (r = -0.82), and children with the lowest TEPSI score had the highest DFMT values. The average DMFT in children with normal development was 1.31, and 3.57 for those with impaired development. This pilot study indicates that the severity of dental caries is correlated with early childhood development. Copyright © 2015. Publicado por Elsevier España, S.L.U.

SPECT/CT localization of oral radioiodine activity: a retrospective study and in-vitro assessment

PubMed Central

Burlison, Jared S.; Hartshorne, Michael F.; Voda, Alan M.; Cocks, Franklin H.

2013-01-01

Purpose We sought to further localize radioiodine activity in the mouth on post-thyroid cancer therapy imaging using single-photon emission computed tomography/computed tomography (SPECT/CT). Materials and methods We retrospectively reviewed all patients (58) who underwent thyroid cancer therapy with iodine-131 (131I) at our institution from August 2009 to March 2011 whose post-therapy radioiodine imaging included neck SPECT/CT. A small group (six) of diagnostic 123I scans including SPECT/CT was also reviewed. Separately, we performed in-vitro 131I (sodium iodide) binding assays with amalgam and Argenco HP 77 (77% dental gold alloy) as proof of principle for these interactions. Results Of the 58 post-therapy patients, 45 (78%) had undergone metallic dental restorations, and of them 41 (91%) demonstrated oral 131I activity localizing preferentially to those restorations. It was observed that radioiodine also localized to other dental restorations and to orthodontic hardware. Gum-line activity in edentulous patients suggests radioiodine interaction with denture adhesive. In vitro, dental amalgam and Argenco HP 77 bound 131I in a time-dependent manner over 1–16 days of exposure. Despite subsequent washings with normal saline, significant 131I activity (maximally 12% for amalgam and 68% for Argenco HP 77) was retained by these metals. Subsequent soaking in a saturated solution of potassium iodide partially displaced 131I from amalgam, with near-total displacement of 131I from Argenco HP 77. Conclusion SPECT/CT shows that radioiodine in the oral cavity localizes to metallic dental restorations. Furthermore, in-vitro studies demonstrate partially reversible binding of 131I to common dental metals. PMID:24128897

The Brisbane Dental Hospital Building: "The Palace" An Era Ends.

PubMed

Akers, Harry F; Foley, Michael A; Brown, John P

2015-01-01

Constitutional, educational, humanitarian and political considerations underpinned the design and construction of the Brisbane Dental Hospital Building, often colloquially referred to as "The Palace." The Queensland Heritage Council's listing of the Brisbane Dental Hospital Building on The Queensland Heritage Register in 1999 confirms the cultural significance of Nowland's architectural signature, the historical importance of the Wickham Park precinct and prior students' connection with the building. Influences on decisions determining the location, grand design and timing of construction of the Brisbane Dental Hospital Building emanated from a far bigger and largely unrecorded political picture. The authors argue that the political context in two tiers of government, the timing and nature of the proposal, town planning issues, the exigencies of the caries epidemic and Forgan Smith's post-Depression economic reconstruction across Queensland underpinned the project. Hanlon's personal attributes and disdain for the autonomy of the dental profession, together with his desire to reform dental education and to establish statewide government-administred dental clinics, were also relevant. Accordingly, the BDHD portrayed aspiration, purpose, symbolism, and vision. This paper, essentially an integration of dental and mainstream history, assembles and analyzes hitherto scattered and unpublished evidence to fill a gap in the current literature.

A 10-year trend of dental treatments under general anesthesia of children in Taipei Veterans General Hospital.

PubMed

Chen, Yung-Pan; Hsieh, Chun-Yi; Hsu, Wen-Ting; Wu, Fu-Ya; Shih, Wen-Yu

2017-04-01

General anesthesia (GA) as a pediatric dental procedure is a well-established method of behavior management. However, studies of pediatric dentistry under GA have mostly focused on handicapped patients, and various retrospective studies in Taiwan have mainly reviewed only a limited number of years. The purpose of the present study was to report trends in pediatric dental treatment performed under GA over the past 10 years. A retrospective review of the hospital records of patients receiving dental treatment under GA from 2006 until 2015 was performed. The patients were divided into three age groups: < 3 years, 3-6 years, and > 6 years. A range of information including basic patient characteristics and types of dental treatment was identified and then analyzed. A total of 791 cases (< 3 years old: 65 cases, 3-6 years old: 492, > 6 years old: 235; 549 male, 242 female) were treated under GA. The case number was found to have increased from 94 during 2006-2007 to 238 during 2014-2015, with the increase being especially pronounced among those aged 3-6 years (2006-2007: 49, 2014-2015: 165). The most common treatments (extraction, restoration, and pulp therapy) were associated with multiple dental caries (684, 86.4%). The < 3-years-old group was characterized by the highest decayed, extracted, and filled surface and decayed, missing, and filled surface indices; the highest mean number of treated teeth; and the highest mean number of treated teeth by composite resin fillings. The 3-6-years-old group had the highest number of primary teeth extractions. The > 6-years-old group had the lowest mean number of treated teeth by stainless-steel crowns (SSCs) and fewest cases treated with pulp therapy. From 2011 onwards, the number of primary tooth extractions significantly increased, while in 2013, there was a crossover whereby the SSC count surpassed the composite resin filling count. Over the past 10 years, there has been an increased use of GA for pediatric dental

Professional and personal enhancement: a pragmatic approach in dental education.

PubMed

Deivanayagam, Kandaswamy; K, Anbarasi

2016-06-01

Students of health education are often offended by the transitions and challenges they face while encountering diverse people, ideas and academic workloads. They may be offended because of reasons not only related to their societal background but also to their basic competence in managing transitions. In the Asian scenario, students enter the first year of professional education in their late teen age along with the definition of self which was created by their parents. There are different issues that arise in this age group that may positively shape or negatively affect the personalities of students. They need to achieve a sense of balance between personal and professional traits on their own. Several students are often unable to cultivate the expected required qualities, which leads to an abject state of mind and hinder their progress. We identified the most common personal and professional hurdles in the lives of dental students and we provided experiential solutions to overcome the hurdles by using a sociable approach through an integrated, continuing education program. Designing and implementing a cohesive, amalgamated and inspiring personal and professional enhancement action program for dental students. Feedback from students reflected that the needs and expectations of students vary with academic phase. In addition students expressed that this program series inculcated some positive skills, and overall, they are satisfied with the utility of the program. Personal and professional enhancement of students in accordance with individual needs as well as with expected requirements needs a committed administrative action plan. Our results in this context are encouraging and can be considered for application in dental institutions.

Shaping dental contract reform: a clinical and cost-effective analysis of incentive-driven commissioning for improved oral health in primary dental care

PubMed Central

Hulme, C; Robinson, P G; Saloniki, E C; Vinall-Collier, K; Baxter, P D; Douglas, G; Gibson, B; Godson, J H; Meads, D; Pavitt, S H

2016-01-01

Objective To evaluate the clinical and cost-effectiveness of a new blended dental contract incentivising improved oral health compared with a traditional dental contract based on units of dental activity (UDAs). Design Non-randomised controlled study. Setting Six UK primary care dental practices, three working under a new blended dental contract; three matched practices under a traditional contract. Participants 550 new adult patients. Interventions A new blended/incentive-driven primary care dentistry contract and service delivery model versus the traditional contract based on UDAs. Main outcome measures Primary outcome was as follows: percentage of sites with gingival bleeding on probing. Secondary outcomes were as follows: extracted and filled teeth (%), caries (International Caries Detection and Assessment System (ICDAS)), oral health-related quality of life (Oral Health Impact Profile-14 (OHIP-14)). Incremental cost-effective ratios used OHIP-14 and quality adjusted life years (QALYs) derived from the EQ-5D-3L. Results At 24 months, 291/550 (53%) patients returned for final assessment; those lost to follow-up attended 6.46 appointments on average (SD 4.80). The primary outcome favoured patients in the blended contract group. Extractions and fillings were more frequent in this group. Blended contracts were financially attractive for the dental provider but carried a higher cost for the service commissioner. Differences in generic health-related quality of life were negligible. Positive changes over time in oral health-related quality of life in both groups were statistically significant. Conclusions This is the first UK study to assess the clinical and cost-effectiveness of a blended contract in primary care dentistry. Although the primary outcome favoured the blended contract, the results are limited because 47% patients did not attend at 24 months. This is consistent with 39% of adults not being regular attenders and 27% only visiting their dentist when

Insights into Ergonomics Among Dental Professionals of a Dental Institute and Private Practitioners in Hubli–Dharwad Twin Cities, India

PubMed Central

Kalghatgi, Shrivardhan; Prasad, Kakarla Veera Venkata; Chhabra, Kumar Gaurav; Deolia, Shravani; Chhabra, Chaya

2014-01-01

Background To assess the knowledge, attitude, and practice of ergonomics among dental professionals of Hubli–Dharwad twin cities, India. Methods Investigator-developed, self-administered, closed-ended questionnaire assessing knowledge, attitude, and practices regarding ergonomics during dental practice was filled in by undergraduates, house surgeons, postgraduates, and faculty members of dental institutions and private practitioners from Hubli–Dharwad twin cities. Results Data were collected from a total of 250 participants, 50 belonging to each academic group. Overall mean knowledge, attitude, and practice scores were 52%, 75%, and 55%, respectively. Significant correlation was found for age with attitude (χ2 = 10.734, p = 0.030) and behavior (χ2 = 12.984, p = 0.011). Marital status was significantly associated with all the three domains; knowledge (χ2 = 29.369, p = 0.000), attitude (χ2 = 29.023, p = 0.000), and practices (χ2 = 13.648, p = 0.009). Conclusion Participants had considerable awareness and behavior toward ergonomics in dental practice. The high attitude score indicates stronger acceptance of ergonomics principles and guidelines during routine dental procedures. The current study highlights the situation of ergonomics in dental practice in the form of knowledge, attitude, and practices. PMID:25516809

[Music therapy in different dental specialties].

PubMed

Mehr, Katarzyna; Wyganowska-Swiatkowska, Marzena; Kowalkowska, Iwona; Kurhańska-Flisykowska, Anna; Piotrowski, Paweł

2012-01-01

Music is generally recognized as the best and, in parallel, the simplest medium of communication. The music therapy, applied in various spheres linked to a therapeutic process, is particularly valued in rehabilitation, medicine, humanities and social sciences. Present study aimed at determination of usefulness of selected techniques of music therapy in different dental specialties. The studies were conducted on 81 generally healthy patients aging 18 to 62 years. Various planned dental procedures were performed first time or were appraised by the patients as unpleasant ones. On the basis of pilot studies, a stable scheme of the visits was established. At the beginning of the studies, music therapy according to Kierył was conducted. Subsequently, basing on description of Schwabe, a form of regulatory individual music therapy was conducted. Depending on psychoemotional condition of the patient, music programming was based on ISO and LEVEL principles, taking into account musical preferences of the patient and his/her age. After every visit the patients filled questionnaires and appropriate results, together with results of studies performed by the dentist, were subjected to statistical analysis. 1. Results of the studies encourage application of musicotherapeutic techniques in different dental specialties. 2. Dental visit can be made attractive and patient's visits in dental office can be facilitated with no significant financial input or organizational.

Oral health status and dental needs of autistic children and young adults.

PubMed

Jaber, Mohamed A; Sayyab, Mohamed; Abu Fanas, Salem H

2011-02-01

  Children with autism might need more dental care than non-autistic, healthy children. The aims of this study were: (a) to describe the caries experience and treatment needs of autistic children aged 6-16 years in the United Arab Emirates; and (b) to provide baseline data at national and regional levels to enable comparisons and future planning of dental services for children with autism.   All children attending a day centre in Sharjah, United Arab Emirates, for autism were selected for the study. Sixty-one autistic children aged 6-16 years (45 males and 16 females) were included in the study. Each patient received a complete oral and periodontal examination using codes and criteria as described by the World Health Organization.   The overall mean for Decayed, Missing, and Filled Teeth/decayed, missing, and filled teeth was 2.4. Female autistic children had significantly higher mean Decayed, Missing, and Filled Teeth/decayed, missing, and filled teeth scores (4.4) than males (1.63). The percentage of decayed, missing, and filled teeth increased with increasing age. The restorative index and met need index for the autistic children aged 11-15 years were 0.02 and 0.10, respectively.   Effective oral health promotion strategies need to be implemented to improve the oral health status of autistic children. © 2010 Blackwell Publishing Asia Pty Ltd.

The effect of health and dental insurance on US children's dental care utilization for urgent and non-urgent dental problems - 2008.

PubMed

Naavaal, Shillpa; Barker, Laurie K; Griffin, Susan O

2017-12-01

We examined the association between utilization of care for a dental problem (utilization-DP) and parent-reported dental problem (DP) urgency among children with DP by type of health care insurance coverage. We used weighted 2008 National Health Interview Survey data from 2,834 children, aged 2-17 years with at least one DP within the 6 months preceding survey. Explanatory variables were selected based on Andersen's model of healthcare utilization. Need was considered urgent if DP included toothache, bleeding gums, broken or missing teeth, broken or missing filling, or decayed teeth and otherwise as non-urgent. The primary enabling variable, insurance, had four categories: none, private health no dental coverage (PHND), private health and dental (PHD), or Medicaid/State Children's Health Insurance Program (SCHIP). Predisposing variables included sociodemographic characteristics. We used bivariate and multivariate analyses to identify explanatory variables' association with utilization-DP. Using logistic regression, we obtained adjusted estimates of utilization-DP by urgency for each insurance category. In bivariate analyses, utilization-DP was associated with both insurance and urgency. In multivariate analyses, the difference in percent utilizing care for an urgent versus non-urgent DP among children covered by Medicaid/SCHIP was 32 percentage points; PHD, 25 percentage points; PHND, 12 percentage points; and no insurance, 14 percentage points. The difference in utilization by DP urgency was higher for children with Medicaid/SCHIP compared with either PHND or uninsured children. Expansion of Medicaid/SCHIP may permit children to receive care for urgent DPs who otherwise may not, due to lack of dental insurance. © 2016 American Association of Public Health Dentistry.

Association between Low blood lead levels and increased risk of dental caries in children: a cross-sectional study.

PubMed

Kim, Young-Suk; Ha, Mina; Kwon, Ho-Jang; Kim, Hae-Young; Choi, Youn-Hee

2017-01-13

The objective of this study was to examine the association between low blood lead levels of <5 μg/dL and the development of dental caries among children. The Children's Health and Environment Research (CHEER) group recruited a cohort of 7,059 school-aged children from six Korean cities. The final study populations in the permanent and deciduous teeth groups were 1,564 and 1,241 children, respectively, after excluding 4 children with blood lead levels of >5 μg/dL. Compared with the children who did not have dental caries, the risk of having dental caries according to blood lead level was estimated by using the zero-inflated negative binomial model. The geometric mean (geometric standard deviation, maximum) blood lead level was 1.53 μg/dL (1.57, 4.89 μg/dL), and 74.4% of children had a level of <2 μg/dL. Blood lead level was significantly higher in the children with than in those without deciduous dental caries (1.59 vs. 1.51 μg/dL), similarly with permanent dental caries (1.65 vs. 1.51 μg/dL). After adjustment for covariates, deciduous teeth surfaces that were decayed and filled increased significantly with increasing blood lead levels in a dose-dependent manner (prevalence ratio, 1.14; 95% confidence interval: 1.02-1.27). However, the risk of having dental caries in permanent teeth was not linearly associated with the increase in blood lead level. In the sum of decayed and filled surfaces, we found a significant increase in risk of dental caries of the deciduous teeth with an increase in blood lead levels (<5 μg/dL) but found no statistical significance in the association with decayed and filled surfaces of caries separately.

Health and safety in the dental clinic - Hygiene regulations for use of elemental mercury in the protection of rights, safety and well-being of the patients, workers and the environment.

PubMed

Ngim, Chunhan; Ngim, Allister Daquan

2013-12-01

The rules governing the use of metallic mercury, a toxic and hazardous chemical, is in most jurisdictions identical to widely accepted standards and practices for handling the same chemical in industry for the protection of humans and their work environment. There cannot be exceptions solely for the practitioner dentists and their patients. Any workplace must be safe for both workers and visitors. The latter being dental patients waiting in the dentist's work environment. We reviewed the literature for toxic health effects of elemental mercury upon humans and present information about the Minimata Convention convened by the United Nations Environment Programme. A study conducted among dentists in Singapore and their personal work environment almost 30 years ago contributed to the workplace standard for elemental mercury, which was reduced, and is still currently enforced as a global standard. We recommend that dentists, with a large alternative battery of restorative materials today, make selection of a restorative material a more seriously considered choice, and not to make use of amalgam without the proper use of personal protective equipment for themselves (members of the dental operating team) and their patients, (amalgam traps and judicious monitoring of their workplace air quality). Mercury is ubiquitous in our presence due to human activities; any reduction in the dentists' workplace contributes to a global reduction. © 2013 Published by Elsevier (Singapore) Pte Ltd.

Predictors of Job Satisfaction in Dental Professionals of the Bosnia and Herzegovina Federation.

PubMed

Muhic, Edin; Plancak, Darije; Lajnert, Vlatka; Muhic, Asja

2016-09-01

Working in a healthy work environment is the ultimate goal of every employee. Dentistry is a stressful career, and the reasons for dissatisfaction are numerous. The aim of this study was to determine the factors of work satisfaction in dental professionals of the Bosnia and Herzegovina Federation. A total of 134 dental professionals selected randomly from the Registry of Dental Chamber of Bosnia and Herzegovina Federation were included in the study. All of them filled out the Demographic Questionnaire and Job Satisfaction Scale (JSS). An increase in the influence of work on the quality of life as well as an increase in its frequency results in leaving the job and significantly reducing the overall job satisfaction. General dental practitioners are significantly more satisfied as compared with specialists. Significant predictors of the job satisfaction are employment status, type of the practice, and availability of dental assistants. General dental practitioners with a dental assistant employed at a private practice are more likely to be satisfied with their jobs. Employment status, practice type and availability of dental assistants are significant predictors of job satisfaction. General dental practitioners working in a private practice with a dental assistant are most likely to be satisfied.

Mercury Contamination - Amalgamate (contract with NFS and ADA). Demonstration of DeHg SM Process. Mixed Waste Focus Area. OST Reference Number 1675

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

1999-09-01

Through efforts led by the Mixed Waste Focus Area (MWFA) and its Mercury Working Group (HgWG), the inventory of bulk elemental mercury contaminated with radionuclides stored at various U.S. Department of Energy (DOE) sites is thought to be approximately 16 m3 (Conley et al. 1998). At least 19 different DOE sites have this type of mixed low-level waste in their storage facilities. The U.S. Environmental Protection Agency (EPA) specifies amalgamation as the treatment method for radioactively contaminated elemental mercury. Although the chemistry of amalgamation is well known, the practical engineering of a sizable amalgamation process has not been tested (Tysonmore » 1993). To eliminate the existing DOE inventory in a reasonable timeframe, scalable equipment is needed that can produce waste forms that meet the EPA definition of amalgamation, produce waste forms that pass the EPA Toxicity Characteristic Leaching Procedure (TCLP) limit of 0.20 mg/L, limit mercury vapor concentrations during processing to below the Occupational Safety and Health Administration’s (OSHA) 8-h worker exposure limit (50 mg/m3) for mercury, and perform the above economically.« less

Payment systems and oral health in Swedish dental care: Observations over six years.

PubMed

Andås, C A; Hakeberg, M

2016-12-01

The aim of this longitudinal study of patients in regular dental care was to compare the findings of manifest caries and fillings after a 6-year adherence to either of two optional payment models, the traditional fee-for service (FFS) model, or the new capitation model 'Dental Care for Health' (DCH). Data on manifest caries lesions, the number of fillings and a number of background variables were collected from both a register and a questionnaire completed by 6,299 regular dental patients who met the inclusion criteria. The influence of payment system adherence and background variables on the number of manifest caries lesions at study end was examined by the means of negative binomial regression analysis. The incidence rate ratio of manifest caries lesions after six years in FFS was 1.5 compared to DCH, after controlling for age, gender, education and pre-baseline caries incidence. The number of fillings was higher in FFS than in DCH at study start and at study end, and was also described by a steeper slope. At group level, this study showed a statistically significant difference between the caries situation after six years in DCH compared with FFS, when some important background factors, including pre-baseline caries, were kept constant in a regression model. Copyright© 2016 Dennis Barber Ltd

Exposure to volatile methacrylates in dental personnel.

PubMed

Hagberg, Stig; Ljungkvist, Göran; Andreasson, Harriet; Karlsson, Stig; Barregård, Lars

2005-06-01

Dental personnel are exposed to acrylates due to the acrylic resin-based composites and bonding agents used in fillings. It is well known that these compounds can cause contact allergy in dental personnel. However, in the 1990s, reports emerged on asthma also caused by methacrylates. The main volatile acrylates in dentistry are 2-hydroxyethyl methacrylate and methyl methacrylate. The aim of this study was to quantify the exposure to these acrylates in Swedish dental personnel. We studied the exposure to 2-hydroxyethyl methacrylate and methyl methacrylate in five randomly selected public dental clinics and at the Faculty of Odontology at Göteborg University. In total, 21 whole-day and 46 task-specific short-term (1-18 min) measurements were performed. The median 8-hour time-weighted averages were 2.5 microg/m3 (dentists) and 2.9 microg/m3 (dental nurses) for 2-hydroxyethyl methacrylate, and 0.8 microg/m3 (dentists) and 0.3 microg/m3 (dental nurses) for methyl methacrylate. The maximum short-term exposure levels were 79 microg/m3 for 2-hydroxyethyl methacrylate and 15 microg/m3 for methyl methacrylate, similar in dentists and dental nurses. The observed levels are much lower than in complete denture fabrication. We found only one previous study in dentistry and it showed similar results (though it reported short-term measurements only). Irritant effects would not be expected in healthy people at these levels. Nevertheless, occupational respiratory diseases due to methacrylates may occur in dental personnel, and improvements in the handling of these chemicals in dentistry are warranted. This includes better vials for the bonding agents and avoiding evaporation from discarded materials.

The influence of social deprivation on dental caries in Swedish children and adolescents, as measured by an index for primary health care: The Care Need Index.

PubMed

Östberg, Anna-Lena; Kjellström, Anna N; Petzold, Max

2017-06-01

The objective was to examine associations between a primary Care Need Index (CNI) and dental caries experience. Dental journal records for 300 988 individuals in western Sweden, aged 3-19 years in 2007-09, were completed with official socioeconomic information. The CNI (independent variable), originally developed for assessing primary care need, was calculated for residential areas (small areas, parishes, dental clinics) based on markers of material deprivation, sociodemographic characteristics, social instability and cultural needs. Dental caries (dependent variable) was registered using the decayed, missing, filled teeth (DMFT) system. Multilevel Poisson regression and logistic regression models were used. All analyses were adjusted for age and gender. In the most deprived areas, the incidence rate ratio (IRR) for dental caries was up to five times higher than in the most affluent areas (reference); in small areas, the IRR for decayed teeth (DT) was 3.74 (95% CI: 3.39-4.12) and 5.11 (CI: 4.45-5.87) for decayed surfaces approximally (DSa). Caries indices including fillings (decayed filled teeth [DFT], decayed filled surfaces approximally [DFSa]) produced lower IRRs, with similar pictures at the parish and dental clinic level. The intracluster correlation was low overall, but stronger at lower geographical levels. The odds ratios for ≥3 caries lesions in the two most deprived areas of the CNI deciles were high, with a DT OR of 3.55 in small areas (95% CI: 3.39-3.73), compared with the eight more affluent deciles. There were strong associations between an index for assessing need in primary care, the CNI and dental caries in Swedish children and adolescents. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

DETERMINATION OF TOTAL MERCURY IN FISH TISSUES USING PYROLYSIS ATOMIC ABSORPTION SPECTROMETRY WITH GOLD AMALGAMATION

EPA Science Inventory

A simple and rapid procedure for measuring total mercury in fish tissues is evaluated and
compared with conventional techniques. Using an automated instrument incorporating combustion, preconcentration by amalgamation with gold, and atomic absorption spectrometry (AAS), mill...

Characteristics of dental attendance among Lithuanian middle-aged university employees.

PubMed

Sakalauskiene, Zana; Maciulskiene, Vita; Vehkalahti, Miira M; Kubilius, Ricardas; Murtomaa, Heikki

2009-01-01

This study aimed to evaluate and describe the dental attendance patterns and to characterize the factors that encourage preventive dental visits among 35- to 44-year-old university employees in Lithuania. A questionnaire survey was conducted anonymously among the 35- to 44-year-old employees (n=862) of four universities in Lithuania in 2005. The response rate was 64% (n=553). Data on their most recent dental visit, habitual dental attendance, and self-reported dental health were collected. Gender, marital status, education, and income levels served as background factors. Of the respondents, 79% were women, and 82% held a university degree. Of all the respondents, 75% reported having their most recent dental visit within the previous 12 months; 19% indicated a preventive check-up as the reason for it (15%--self-decided visit and 4%--dentist's recall). The most common treatments received were fillings (75%), scaling and cleaning (28%), and endodontic treatment (22%). Analysis of the data about habitual dental attendance showed that preventive check-up as the main reason for attendance was more commonly reported by women (OR=1.7), among those who indicated having lost fewer teeth (OR=1.5), reported higher incomes (OR=1.4), and who indicated a shorter time interval since their most recent dental visit (OR=1.3). Dental problem seems to be a dominant reason for dental attendance in Lithuania where both dentists' and patients' behavior weakly reflects preventive orientation.

Time utilization, productivity and costs of solo and extended duty auxiliary dental practice.

PubMed

Tan, H H; van Gemert, H G

1977-07-01

A study was conducted to compare the time utilization of the dentist, and productivity and costs for solo (one dentist, one chairside assistant and one treatment room) and extended duty settings (one dentist, two extended duty dental hygienists, one chairside assistant and two treatment rooms). Only amalgam and composite restorations done in a general group practice were included. In the extended duty setting the dentist spent more time in managerial activities and less time in treatment than in the solo setting. Nevertheless, the dentist in the extended duty setting produced 53% more restorations as compared with solo practice. The cost ratio of solo to extended duty practice was computed to 1:1.52. From the point of view of microeconomics, the extended duty setting was found no worse than the solo setting.

Poor quality evidence suggests that failure rates for atraumatic restorative treatment and conventional amalgam are similar.

PubMed

Hurst, Dominic

2012-06-01

The Medline, Cochrane CENTRAL, Biomed Central, Database of Open Access Journals (DOAJ), OpenJ-Gate, Bibliografia Brasileira de Odontologia (BBO), LILACS, IndMed, Sabinet, Scielo, Scirus (Medicine), OpenSIGLE and Google Scholar databases were searched. Hand searching was performed for journals not indexed in the databases. References of included trials were checked. Prospective clinical trials with test and control groups with a follow up of at least one year were included. Data abstraction was conducted independently and clinical and methodologically homogeneous data were pooled using a fixed-effects model. Eighteen trials were included. From these 32 individual dichotomous datasets were extracted and analysed. The majority of the results show no differences between both types of intervention. A high risk of selection-, performance-, detection- and attrition bias was identified. Existing research gaps are mainly due to lack of trials and small sample size. The current evidence indicates that the failure rate of high-viscosity GIC/ART restorations is not higher than, but similar to that of conventional amalgam fillings after periods longer than one year. These results are in line with the conclusions drawn during the original systematic review. There is a high risk that these results are affected by bias, and thus confirmation by further trials with suitably high numbers of participants is needed.

Structure of dental gallium alloys.

PubMed

Herø, H; Simensen, C J; Jørgensen, R B

1996-07-01

The interest in gallium alloys as a replacement for amalgam has increased in recent years due to the risk of environmental pollution from amalgam. Alloy powders with compositions close to those for alloys of amalgam are mixed with a liquid gallium alloy. The mix is condensed into a prepared cavity in much the same way as for amalgam. The aim of the present work was to study the structure of: (1) two commercial alloy powders containing mainly silver, tin and copper, and (2) the phases formed by mixing these powders with a liquid alloy of gallium, indium and tin. One of the alloy powders contained 9 wt% palladium. Cross-sections of cylindrical specimens made by these gallium mixes were investigated by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. Discrete grains of the following phases were found to be present in both gallium alloys: hexagonal Ag2Ga, tetragonal Cu(Pd)Ga2, cubic Ag9In4 and tetragonal beta-Sn. Indications of hexagonal or orthorhombic Ag2Sn were found in the remaining, unreacted alloy particles. In the palladium-containing alloy the X-ray reflections indicate a minor fraction of cubic Cu9Ga4 in addition to the Cu(Pd)Ga2 phase. Particles of beta-Sn are probably precipitated because Sn-Ga phases cannot be formed according to the binary phase diagram.

Vital Pulp Therapy—Current Progress of Dental Pulp Regeneration and Revascularization

PubMed Central

Zhang, Weibo; Yelick, Pamela C.

2010-01-01

Pulp vitality is extremely important for the tooth viability, since it provides nutrition and acts as biosensor to detect pathogenic stimuli. In the dental clinic, most dental pulp infections are irreversible due to its anatomical position and organization. It is difficult for the body to eliminate the infection, which subsequently persists and worsens. The widely used strategy currently in the clinic is to partly or fully remove the contaminated pulp tissue, and fill and seal the void space with synthetic material. Over time, the pulpless tooth, now lacking proper blood supply and nervous system, becomes more vulnerable to injury. Recently, potential for successful pulp regeneration and revascularization therapies is increasing due to accumulated knowledge of stem cells, especially dental pulp stem cells. This paper will review current progress and feasible strategies for dental pulp regeneration and revascularization. PMID:20454445

Dental caries prevalence and its association with fluoride level in drinking water in Sana'a, Yemen

PubMed Central

Al-Akwa, Ameen Abdullah; Al-Maweri, Sadeq Ali

2018-01-01

Objectives: Dental caries is the most prevalent chronic condition affecting schoolchildren worldwide. This study is aimed to assess the prevalence of dental caries among schoolchildren in urban and rural districts of Sana'a governorate, Yemen, and to investigate the correlation between caries experience and level of fluoride in drinking water, age, gender, and residence. Materials and Methods: This school-based survey involved 17,599 schoolchildren (aged 6–12 years), of whom 9623 were boys and 7976 were girls. We used decay-missing-filled teeth/decay-filled teeth (DMFT/dft) indices to evaluate dental caries experience. In addition, fluoride concentration in drinking water was investigated. Results: Around 67.6% of children had dental caries. Children residing in urban districts had significantly higher mean scores of DMFT/dft than those in rural areas (P < 0.05). A significant negative correlation between caries experience and fluoride level was found (P < 0.05), with the lowest dft/DMFT scores at the optimum fluoride level of 0.61–2 ppm and the highest at two extremes, 0.0–0.4 ppm and >2 ppm. Conclusion: This survey found a very high prevalence of caries among schoolchildren in Yemen. There was also an inverse relation between dental caries experience and fluoride levels. PMID:29657520

Dental health status and treatment needs in the infantry regiment of the Malaysian Territorial Army.

PubMed

Jasmin, Borhan; Jaafar, Nasruddin

2011-04-01

The aim of this study was to determine the dental health status and treatment needs of personnel in the Infantry Regiment of the Malaysian Territorial Army (TA).This cross-sectional study involved stratified and systematic random sampling with a total sample size of 300. Dental health status and treatment needs were assessed using the standard WHO oral assessment criteria (1997). The prevalence of caries experience was 96% (mean ± SD DMFT [decayed, missing, filled teeth] = 8.0 ± 5.5). Active decay prevalence was high (85%; mean ± SD = 3.6 ± 3.1) indicating high unmet treatment need. Missing teeth prevalence was high (69%; mean ± SD = 2.8 ± 3.7). Filled teeth prevalence was low (56%, mean ± SD = 1.5 ± 2.0). In all, 90% of participants required some form of dental treatment, of whom 85% required restorative treatment, 5% advanced restorative treatment, 36.7% extractions, and 45.3% prosthetic treatment. These findings suggest that there was a high need for dental treatment in the Infantry Battalions of Malaysian TA Regiments and the service must be made available to cater to the needs.

Study of tin amalgam mirrors by 1 1 9 Sn Mössbauer spectroscopy and other analytical methods

NASA Astrophysics Data System (ADS)

Lerf, A.; Wagner, F. E.; Herrera, L. K.; Justo, A.; Mu noz-Páez, A.; Pérez-Rodríguez, J. L.

2016-12-01

From the beginning of the 16 th until the end of the 19 th century the most widely used mirrors consisted of a pane of glass backed with a reflecting layer of tin-mercury amalgam. They were made by sliding the glass pane over a tin foil covered with liquid mercury. After removal of the superfluous mercury, tin amalgam formed slowly at ambient temperature and yielded a reflecting layer adhering to the surface of the glass. Such mirrors often deteriorate in the course of time by oxidation of the tin in the amalgam to stannous or stannic oxide. 119Sn Mössbauer spectroscopy, scanning electron microscopy, micro-XRF and X-ray diffraction have been used to study this deterioration process. The studied specimens were a modern mirror made for the reconstruction of the Green Vault in Dresden in the early 2000s, two rather well preserved German mirrors from the 17 th and 19 th centuries and several strongly deteriorated specimens of Baroque mirrors from the south of Spain. The modern mirror consists mainly of a Sn0.9Hg0.1 amalgam with only 2 % of SnO2. The older German mirrors showed more pronounced oxidation, containing 12 and 15 % of SnO2, which did not noticeably impair their reflectivity. In the samples from the Spanish mirrors at best a few percent of metallic phase was left. The majority of the tin had oxidised to SnO2, but between 8 and 20 % of the tin was present as SnO. X-ray diffraction yielded similar results and micro-XRF mapping using synchrotron radiation for excitation gave information on the distribution of Sn and Hg in the reflecting layer of the mirrors.

Access to Fluoridated Water and Adult Dental Caries: A Natural Experiment.

PubMed

Peres, M A; Peres, K G; Barbato, P R; Höfelmann, D A

2016-07-01

Systematic reviews have found no evidence to support a benefit of water fluoridation (WF) to prevent dental caries in adult populations. The aim of this natural experiment was to investigate whether lifetime access to fluoridated water is associated with dental caries experience among adults from Florianópolis, Brazil. The data originated from a population-based cohort study (EpiFloripa Adult) initiated in 2009 (n = 1,720) when participants were aged 20 to 59 years. The second wave was carried out in 2012 (n = 1,140) and included a dental examination and a face-to-face questionnaire. Participants residing at the same address since the age of 7 y or before were included in the primary analyses. Sensitivity analyses were also performed. WF was implemented in the city in 2 different periods of time: 1982 (60% of the population) and 1996. Dental caries was assessed by the decayed, missing, and filled teeth (DMFT) index. A combination of residential status, participant's age, and year of implementation of WF permitted the creation of participants' lifetime access to fluoridated water: >75%, 50% to 75%, and <50% of a participant's lifetime. Covariates included sex, age, socioeconomic mobility, educational attainment, income, pattern of dental attendance, and smoking. Participants who accessed fluoridate water <50% of their lifetime presented a higher mean rate ratio of DMFT (1.39; 95% CI, 1.05-1.84) compared with those living >75% of their lifetime with residential access to fluoridated water. Participants living between 50% and 75% and <50% of their lives in fluoridated areas presented a decayed and filled teeth mean ratio of 1.34 (95% CI, 1.02-1.75) and 1.47 (95% CI, 1.05-2.04) higher than those with residential access to fluoridated water >75% of their lifetime, respectively. Longer residential lifetime access to fluoridated water was associated with less dental caries even in a context of multiple exposures to fluoride. © International & American Associations for

The Department of Defense Retiree Dental Program.

DTIC Science & Technology

1997-05-01

treatment. An age/sex factor was also developed for orthodontics (Table 13). 76 Table 13 Retiree and Dependent Eligible Population Age Bracket Age...does not cover the more costly dental procedures such as orthodontics , endodontics, periodontics, single crowns, and fixed and removable...program under section 1076a of title 10, United States Code. Orthodontic services, crowns, gold fillings, bridges, complete or partial dentures, and

The effect of lifetime fluoridation exposure on dental caries experience of younger rural adults.

PubMed

Crocombe, L A; Brennan, D S; Slade, G D; Stewart, J F; Spencer, A J

2015-03-01

The aim of this study was to confirm whether the level of lifetime fluoridation exposure is associated with lower dental caries experience in younger adults (15-46 years). Data of the cohort born between 1960 and 1990 residing outside Australia's capital cities from the 2004-2006 Australian National Survey of Adult Oral Health were analysed. Residential history questionnaires were used to determine the percentage of each person's lifetime exposure to fluoridated water (<50%/50+%). Examiners recorded decayed, missing and filled permanent teeth (DMFT). Socio-demographic variables, periodontal risk factors, and access to dental care were included in multivariable least-squares regression models. In bivariate analysis, the higher level of fluoridation category had significantly lower DMFT (mean 6.01 [SE=0.62]) than the lower level of fluoridation group (9.14 [SE=0.73] p<0.01) and lower numbers of filled teeth (4.08 [SE=0.43], 7.06 [SE=0.62], p<0.01). In multivariate analysis, the higher number of full-time equivalent dentists per 100,000 people was associated with a lower mean number of missing teeth (regression coefficient estimate=-1.75, p=0.03), and the higher level of water fluoridation with a lower mean DMFT (-2.45, p<0.01) and mean number of filled teeth (-2.52, p<0.01). The higher level of lifetime fluoridation exposure was associated with substantially lower caries experience in younger rural adults, largely due to a lower number of filled teeth. © 2015 Australian Dental Association.

Detecting the manipulation of digital clinical records in dental practice.

PubMed

Díaz-Flores-García, V; Labajo-González, E; Santiago-Sáez, A; Perea-Pérez, B

2017-11-01

Radiography provides many advantages in the diagnosis and management of dental conditions. However, dental X-ray images may be subject to manipulation with malicious intent using easily accessible computer software. In this study, we sought to evaluate a dentist's ability to identify a manipulated dental X-ray images, when compared with the original, using a variant of the methodology described by Visser and Kruger. Sixty-six dentists were invited to participate and evaluate 20 intraoral dental X-ray images, 10 originals and 10 modified, manipulated using Adobe Photoshop to simulate fillings, root canal treatments, etc. Participating dentists were correct in identifying the manipulated image in 56% of cases, 6% higher than by chance and 10% more than in the study by Visser and Kruger. Malicious changes to dental X-ray images may go unnoticed even by experienced dentists. Professionals must be aware of the legal consequences of such changes. A system of detection/validation should be created for radiographic images. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

Residual mercury content and leaching of mercury and silver from used amalgam capsules.

PubMed

Stone, M E; Pederson, E D; Cohen, M E; Ragain, J C; Karaway, R S; Auxer, R A; Saluta, A R

2002-06-01

The objective of this investigation was to carry out residual mercury (Hg) determinations and toxicity characteristic leaching procedure (TCLP) analysis of used amalgam capsules. For residual Hg analysis, 25 capsules (20 capsules for one brand) from each of 10 different brands of amalgam were analyzed. Total residual Hg levels per capsule were determined using United States Environmental Protection Agency (USEPA) Method 7471. For TCLP analysis, 25 amalgam capsules for each of 10 brands were extracted using a modification of USEPA Method 1311. Hg analysis of the TCLP extracts was done with USEPA Method 7470A. Analysis of silver (Ag) concentrations in the TCLP extract was done with USEPA Method 6010B. Analysis of the residual Hg data resulted in the segregation of brands into three groups: Dispersalloy capsules, Group A, retained the most Hg (1.225 mg/capsule). These capsules were the only ones to include a pestle. Group B capsules, Valliant PhD, Optaloy II, Megalloy and Valliant Snap Set, retained the next highest amount of Hg (0.534-0.770 mg/capsule), and were characterized by a groove in the inside of the capsule. Group C, Tytin regular set double-spill, Tytin FC, Contour, Sybraloy regular set, and Tytin regular set single-spill retained the least amount of Hg (0.125-0.266 mg/capsule). TCLP analysis of the triturated capsules showed Sybraloy and Contour leached Hg at greater than the 0.2 mg/l Resource Conservation and Recovery Act (RCRA) limit. This study demonstrated that residual mercury may be related to capsule design features and that TCLP extracts from these capsules could, in some brands, exceed RCRA Hg limits, making their disposal problematic. At current RCRA limits, the leaching of Ag is not a problem.

Child dental fear and general emotional problems: a pilot study.

PubMed

Krikken, J B; ten Cate, J M; Veerkamp, J S J

2010-12-01

This was to investigate the relation between general emotional and behavioural problems of the child and dental anxiety and dental behavioural management problems. Dental treatment involves many potentially unpleasant stimuli, which all may lead to the development of dental anxiety and behavioural management problems (BMP). It is still unclear why some children get anxious in the dental situation while others, with a comparable dental history, do not. Besides the latent inhibition theory it is suggested that this can be explained by differences in child rearing and personality traits. The sample consisted of 50 children (4-12 years old) and their parents participated in this study. Parents filled out the Child Fear Survey Schedule Dental Subscale (CFSS-DS) and the Child Behaviour Checklist (CBCL) on behalf of their child. Child behaviour during consecutive dental treatments was assessed using the Venham scale. There were 39 children subject to analysis (21 boys) with a mean CFSS score of 40.4. Children aged 4 and 5 years who had sleeping problems, attention problems and aggressive behaviour, as scored by parents on the CBCL, displayed more disruptive behaviour during dental treatment. Children with emotionally/ reactive and attention problems were more anxious. In this pilot study a possible relation between general emotional and behavioural problems of young children and dental anxiety was shown. Also a relation between emotional and behavioural problems and dental behavioural management problems was shown. Because of the small number of subjects in our study, further research will be needed to confirm these results.

Plasmonic detection of mercury via amalgam formation on surface-immobilized single Au nanorods

NASA Astrophysics Data System (ADS)

Schopf, Carola; Martín, Alfonso; Iacopino, Daniela

2017-12-01

Au nanorods were used as plasmonic transducers for investigation of mercury detection through a mechanism of amalgam formation at the nanorod surfaces. Marked scattering color transitions and associated blue shifts of the surface plasmon resonance peak wavelengths (λmax) were measured in individual nanorods by darkfield microscopy upon chemical reduction of Hg(II). Such changes were related to compositional changes occurring as a result of Hg-Au amalgam formation as well as morphological changes in the nanorods' aspect ratios. The plot of λmax shifts vs. Hg(II) concentration showed a linear response in the 10-100 nM concentration range. The sensitivity of the system was ascribed to the narrow width of single nanorod scattering spectra, which allowed accurate determination of peak shifts. The system displayed good selectivity as the optical response obtained for mercury was one order of magnitude higher than the response obtained with competitor ions. Analysis of mercury content in river and tap water were also performed and highlighted both the potential and limitation of the developed method for real sensing applications.

THE PREPARATION AND STABILITY OF CARRIER-FREE AMALGAMS. Annual Report, June 1960-July 1961

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kahn, M.; Hamester, H.L.

1962-10-31

Results of investigations concerning the preparation and properties of amalgams of 10.6-hour carrier-free Pb/sup 212/ and the radiocolloidal and adsorptive properties of carrierfree Ag/sup 110/ are reported. Data and discussion related to recovery of Pb/sup 212/ activity from active acetic acidhydroxylamine hydrochloride -potassium bitartrate electrolyte are presented along with similar information on stability and homogeneity of Pb/sup 212/ -Hg amalgams. In work on Ag/sup 110/ the rate of carrier-free Ag adsorption by glass, teflon, polyethylene, and precipitates, and the formation rate of carrier- free radiocolloids was initiated. Data are included on Ag adsorption from nitric acid solutions on pyrex atmore » 3l.8 deg C as a function of reagent concentration and time. Also included are data on adsorption of glass from water, ammonium hydroxide, and sodium carbonate, and from perchloric, hydrochloric, acetic, and sulfuric acid solutions. (J.R.D.)« less

Work shadowing in dental teaching practices: evaluation results of a collaborative study between university and general dental practices.

PubMed

Heitkamp, Stefan J; Rüttermann, Stefan; Gerhardt-Szép, Susanne

2018-05-08

The aim of this study was to investigate the acceptance and assessment of work shadowing carried out by students and dentists in dental practices. Furthermore, the extent to which students perceive an improvement in their specialised, communication and social competencies, was to be examined. 61 dental students in their clinical semesters at a German university participated in work shadowing placements at 27 different general dental practices. Before beginning, they received checklists of various competencies that they self-assessed using school grades (from 1 = 'very good', to 6 = 'failed'), which they also repeated after completion. The dentists supplemented this with their external assessments. In addition, the students were requested to fill out a 54-item questionnaire and compose a freely-structured report after the work shadowing; the dentists filled out a questionnaire containing 16 items. The statistical analysis was carried out by means of the Friedman Test, including a post-hoc test (Bonferroni-Holm correction). The analysis showed a significant overall improvement in the students' self-assessed competencies by 0.71* ± 0.43 grades. With an average of 0.33* ± 0.36, the dentists' external assessment proved significantly higher than the self-assessment. The greatest improvements were perceived by the students in the areas of accounting (1.17* ± 0.77), practice organisation (1.05* ± 0.61) and dentist's discussions (0.94* ±0.80) [*p < 0.05]. The students confirmed experiencing an expansion of knowledge, an improvement in their communication skills and indicated a high degree of satisfaction in regard to the dentists (school grade 1.58 ± 0.93). A maximum amount of satisfaction towards the work shadow students was demonstrated by the dentists, and this form of teaching was assessed with a school grade of 1.69 ± 0.89. Both students and dental practitioners demonstrated a high level of satisfaction in regard to the work

Effect of amalgam corrosion products in non-discolored dentin on the bond strength of replaced composite resin

PubMed Central

Ghavamnasiri, Marjaneh; Eslami, Samaneh; Ameri, Hamide; Chasteen, Joseph E.; Majidinia, Sara; Moghadam, Fatemeh Velayaty

2015-01-01

Objectives: To evaluate the effect of amalgam corrosion products in non-discolored dentin on the bond strength of replaced composite resin. Materials and Methods: One hundred and sixty-one Class I cavities were prepared on extracted premolars and divided into seven groups. Group 1: Light-cured composite; Groups 2, 3, and 4: Amalgam stored in 37°C normal saline for respectively 1, 3, and 6 months and then replaced with composite leaving the cavity walls intact. Groups 5, 6, and 7: Identical to Groups 2, 3, and 4, except the cavity walls were extended 0.5 mm after amalgam removal. Eighteen specimens from each group were selected for shear bond strength testing, while on remaining five samples, elemental microanalysis was conducted. Data were analyzed using Mann-Whitney and Freidman (α = 0.05). Results: There was a significant difference between Groups 1 and 4 and also between Group 1 and Groups 5, 6, and 7. However, Groups 1, 2, and 3 showed no significant difference regarding bond strength. Bond strengths of Group 4 was significantly less than Groups 2 and 3. However, Groups 5, 6, and 7 showed similar bond strength. There was no difference among all groups in terms of metal elements at any storage times. PMID:25657522

Dental caries and preterm birth: a systematic review and meta-analysis.

PubMed

Wagle, Madhu; D'Antonio, Francesco; Reierth, Eirik; Basnet, Purusotam; Trovik, Tordis A; Orsini, Giovanna; Manzoli, Lamberto; Acharya, Ganesh

2018-03-02

The primary objective of this systematic review was to evaluate the association between dental caries and preterm birth (PTB). The secondary objective was ascertaining the difference between women with dental caries who experienced PTB and those who did not with regard to decayed, missing and filled teeth (DMFT), and decayed, missing and filled surfaces (DMFS) indices. MEDLINE, Embase, CINAHL and Cochrane databases were searched initially in November 2015 and repeated in December 2016. We included observational cohort and case-control studies. Only studies reporting the risk of PTB in women affected compared with those not affected by dental caries in pregnancy were included. Random-effect meta-analyses were used to compute the summary OR of PTB among women with caries versus women without caries, and the mean difference in either DMFT or DMFS indices between women experiencing PTB and those without PTB. Nine observational studies (4826 pregnancies) were included. Women affected by dental caries during pregnancy did not show a significantly higher risk of PTB (OR: 1.16, 95% CI 0.90 to 1.49, P=0.25, I 2 =35%). Also, the women with PTB did not show significantly higher DMFT or DMFS indices (summary mean differences: 1.56, P=0.10; I 2 =92% and -0.15, P=0.9, I 2 =89%, respectively). Dental caries does not appear to be a substantial risk factor for PTB. NCT01675180; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Evaluation of the amalgamation reaction of experimental Ag-Sn-Cu alloys containing Pd using a mercury plating technique.

PubMed

Koike, Marie; Ferracane, Jack L; Fujii, Hiroyuki; Okabe, Toru

2003-09-01

A mercury plating technique was used to determine the phases forming on experimental Ag-Sn-Cu alloy powders (with and without Pd) exposed to electrolytically deposited mercury. Four series of alloy powders were made: a) 1.5% Pd with 10-14% Cu (CU series); b) 1.0% Pd with 10-14% Cu (1PD series); c) 1.5% Pd with different ratios of Ag3Sn (gamma) to Ag4Sn (beta) with 12% Cu (AGSN series); and d) 9-13% Cu with no Pd (NOPD series). Each powder was pressed on a freshly prepared amalgam specimen made from the same powder and metallographically polished until cross sections appeared; mercury was electroplated on the alloy particles. Alloy powders, amalgams and electroplated specimens were examined using XRD and SEM/EDS. XRD confirmed the presence of gamma2 in amalgams made from alloys with Cu < 13% or with Ag3Sn/Ag4Sn > 0.8. Specimens with moderately plated Hg showed gamma1 (Ag2Hg3) polyhedra and eta' Cu6Sn5, but not gamma2. This method effectively identifies alloys prone to forming gamma2.

Increased Mercury Levels in Patients with Celiac Disease following a Gluten-Free Regimen

PubMed Central

Elli, Luca; Rossi, Valentina; Conte, Dario; Ronchi, Anna; Tomba, Carolina; Passoni, Manuela; Bardella, Maria Teresa; Roncoroni, Leda; Guzzi, Gianpaolo

2015-01-01

Background and Aim. Although mercury is involved in several immunological diseases, nothing is known about its implication in celiac disease. Our aim was to evaluate blood and urinary levels of mercury in celiac patients. Methods. We prospectively enrolled 30 celiac patients (20 treated with normal duodenal mucosa and 10 untreated with duodenal atrophy) and 20 healthy controls from the same geographic area. Blood and urinary mercury concentrations were measured by means of flow injection inductively coupled plasma mass spectrometry. Enrolled patients underwent dental chart for amalgam fillings and completed a food-frequency questionnaire to evaluate diet and fish intake. Results. Mercury blood/urinary levels were 2.4 ± 2.3/1.0 ± 1.4, 10.2 ± 6.7/2.2 ± 3.0 and 3.7 ± 2.7/1.3 ± 1.2 in untreated CD, treated CD, and healthy controls, respectively. Resulting mercury levels were significantly higher in celiac patients following a gluten-free diet. No differences were found regarding fish intake and number of amalgam fillings. No demographic or clinical data were significantly associated with mercury levels in biologic samples. Conclusion. Data demonstrate a fourfold increase of mercury blood levels in celiac patients following a gluten-free diet. Further studies are needed to clarify its role in celiac mechanism. PMID:25802516

Methamphetamine Users Have Increased Dental Disease: A Propensity Score Analysis.

PubMed

Shetty, V; Harrell, L; Clague, J; Murphy, D A; Dye, B A; Belin, T R

2016-07-01

Methamphetamine (MA) users are assumed to have a high burden of tooth decay. Less clear is how the distribution and severity of dental caries in MA users differ from the general population. Using a covariate-balancing propensity score strategy, we investigated the differential effects of MA use on dental caries by comparing the patterns of decayed, missing, and filled teeth in a community sample of 571 MA users with a subset of 2,755 demographically similar control individuals selected from a National Health and Nutrition Examination Survey (NHANES) cohort. Recruited over a 2-y period with a stratified sampling protocol, the MA users underwent comprehensive dental examinations by 3 trained and calibrated dentists using NHANES protocols. Propensity scores were estimated with logistic regression based on background characteristics, and a subset of closely matched subjects was stratified into quintiles for comparisons. MA users were twice as likely to have untreated caries (odds ratio [OR] = 2.08; 95% confidence interval [95% CI]: 1.55 to 2.78) and 4 times more likely to have caries experience (OR = 4.06; 95% CI: 2.24 to 7.34) than the control group of NHANES participants. Additionally, MA users were twice as likely to have 2 more decayed, missing, or filled teeth (OR = 2.08; 95% CI: 1.29 to 2.79) than the NHANES participants. The differential involvement of the teeth surfaces in MA users was quite distinctive, with carious surface involvement being highest for the maxillary central incisors, followed by maxillary posterior premolars and molars. Users injecting MA had significantly higher rates of tooth decay compared with noninjectors (P = 0.04). Although MA users experienced decayed and missing dental surfaces more frequently than NHANES participants, NHANES participants had more restored surfaces, especially on molars. The high rates and distinctive patterns of dental caries observed could be used 1) to alert dentists to covert MA use in their patients and 2) as

Predictors of Job Satisfaction in Dental Professionals of the Bosnia and Herzegovina Federation

PubMed Central

Muhic, Edin; Plancak, Darije; Muhic, Asja

2016-01-01

Introduction Working in a healthy work environment is the ultimate goal of every employee. Dentistry is a stressful career, and the reasons for dissatisfaction are numerous. Aim The aim of this study was to determine the factors of work satisfaction in dental professionals of the Bosnia and Herzegovina Federation. Materials and methods A total of 134 dental professionals selected randomly from the Registry of Dental Chamber of Bosnia and Herzegovina Federation were included in the study. All of them filled out the Demographic Questionnaire and Job Satisfaction Scale (JSS). Results An increase in the influence of work on the quality of life as well as an increase in its frequency results in leaving the job and significantly reducing the overall job satisfaction. General dental practitioners are significantly more satisfied as compared with specialists. Significant predictors of the job satisfaction are employment status, type of the practice, and availability of dental assistants. General dental practitioners with a dental assistant employed at a private practice are more likely to be satisfied with their jobs. Conclusions Employment status, practice type and availability of dental assistants are significant predictors of job satisfaction. General dental practitioners working in a private practice with a dental assistant are most likely to be satisfied. PMID:27847395

Dental fear and oral health and family characteristics of Finnish children.

PubMed

Rantavuori, Kari; Lahti, Satu; Hausen, Hannu; Seppä, Liisa; Kärkkäinen, Sakari

2004-08-01

Our aim was to describe the occurrence of dental fear among Finnish children of different ages and to ascertain how oral health and family characteristics are associated with dental fear. The subject groups were aged 3, 6, 9, 12, and 15 years in two middle-sized cities, and the 1474 participants were distributed over fairly equal samples of each age. A questionnaire given to each child to be filled out at home enquired about social background, oral hygiene habits, diet, and dental fear. Oral health status was examined clinically and radiographically by two calibrated dentists. Multiple logistic regression analyses were performed for each age group in order to study the associations between dental fear and selected factors. Dental fear was higher among 12- and 15-year-old children than among the younger ones. Pain, drilling, and local anesthesia were reported to be the most frightening aspects. Excluding the 12-year-olds, children whose family members reported dental fear were more likely to report dental fear than children whose family members did not report dental fear. Six- and 12-year-olds who had experienced caries were more likely to report dental fear than were caries-free children. Among 6-year-olds, father's education modified the effect of a child's caries experience on child dental fear. Frequent intake of sugary items and a limit on eating candies to only one day per week were associated with higher dental fear. Fear of dental treatment is still fairly common among Finnish children, and the factors associated with it differ with the age of the child.

Education About Dental Hygienists' Roles in Public Dental Prevention Programs: Dental and Dental Hygiene Students' and Faculty Members' and Dental Hygienists' Perspectives.

PubMed

Pervez, Anushey; Kinney, Janet S; Gwozdek, Anne; Farrell, Christine M; Inglehart, Marita R

2016-09-01

In 2005, Public Act No. 161 (PA 161) was passed in Michigan, allowing dental hygienists to practice in approved public dental prevention programs to provide services for underserved populations while utilizing a collaborative agreement with a supervising dentist. The aims of this study were to assess how well dental and dental hygiene students and faculty members and practicing dental hygienists have been educated about PA 161, what attitudes and knowledge about the act they have, and how interested they are in additional education about it. University of Michigan dental and dental hygiene students and faculty members, students in other Michigan dental hygiene programs, and dental hygienists in the state were surveyed. Respondents (response rate) were 160 dental students (50%), 63 dental hygiene students (82%), 30 dental faculty members (26%), and 12 dental hygiene faculty members (52%) at the University of Michigan; 143 dental hygiene students in other programs (20%); and 95 members of the Michigan Dental Hygienists' Association (10%). The results showed that the dental students were less educated about PA 161 than the dental hygiene students, and the dental faculty members were less informed than the dental hygiene faculty members and dental hygienists. Responding dental hygiene faculty members and dental hygienists had more positive attitudes about PA 161 than did the students and dental faculty members. Most of the dental hygiene faculty members and dental hygienists knew a person providing services in a PA 161 program. Most dental hygiene students, faculty members, and dental hygienists wanted more education about PA 161. Overall, the better educated about the program the respondents were, the more positive their attitudes, and the more interested they were in learning more.

Preparation and properties of calcium-silicate filled resins for dental restoration. Part I: chemical-physical characterization and apatite-forming ability.

PubMed

Profeta, Andrea Corrado

2014-11-01

The aim of this study was to measure dimensional changes due to hygroscopic expansion and the bioactivity of two experimental methacrylate-based dental adhesives either incorporating Bioglass 45S5 (3-E&RA/BG) or MTA (3-E&RA/WMTA). 3-E&RA/BG, 3-E&RA/WMTA and a control filler-free resin blend (3-E&RA) were formulated from commercially available monomers. Water sorption (WS) and solubility (SL) behaviour were evaluated by weighing material disks at noted intervals; the relationship between degree of hydration and the glass transition temperature (Tg) was investigated by using differential scanning calorimetry (DSC). In vitro apatite-forming ability as a function of soaking time in phosphate-containing solutions was also determined. Kruskal-Wallis analysis of variance (ANOVA) was used to evaluate differences between groups for maximum WS, SL, net water uptake and the percentage change in Tg values. Post-ANOVA pair-wise comparisons were conducted using Mann-Whitney-U tests. 3-E&RA/BG and 3-E&RA/WMTA exhibited values of maximum WS and net water uptake that were significantly higher when compared to 3-E&RA. However, no statistically significant differences were observed in terms of SL between all the adhesives. The addition of the Bioglass 45S5 and MTA to the 3-E&RA showed no reduction of the Tg after 60 days of storage in deionized water. ATR Fourier Transform Infrared Spectroscopy (ATR-FTIR) of the filled resin disks soaked in DPBS for 60 days showed the presence of carbonate ions in different chemical phases. Dentine bonding agents comprising calcium-silicates are not inert materials in a simulated oral environment and apatite formation may occur in the intra-oral conditions. A bioactive dental material which forms apatite on the surface would have several benefits including closure of gaps forming at the resin-dentine interface and potentially better bond strength over time (less degradation of bond).

Shaping dental contract reform: a clinical and cost-effective analysis of incentive-driven commissioning for improved oral health in primary dental care.

PubMed

Hulme, C; Robinson, P G; Saloniki, E C; Vinall-Collier, K; Baxter, P D; Douglas, G; Gibson, B; Godson, J H; Meads, D; Pavitt, S H

2016-09-08

To evaluate the clinical and cost-effectiveness of a new blended dental contract incentivising improved oral health compared with a traditional dental contract based on units of dental activity (UDAs). Non-randomised controlled study. Six UK primary care dental practices, three working under a new blended dental contract; three matched practices under a traditional contract. 550 new adult patients. A new blended/incentive-driven primary care dentistry contract and service delivery model versus the traditional contract based on UDAs. Primary outcome was as follows: percentage of sites with gingival bleeding on probing. Secondary outcomes were as follows: extracted and filled teeth (%), caries (International Caries Detection and Assessment System (ICDAS)), oral health-related quality of life (Oral Health Impact Profile-14 (OHIP-14)). Incremental cost-effective ratios used OHIP-14 and quality adjusted life years (QALYs) derived from the EQ-5D-3L. At 24 months, 291/550 (53%) patients returned for final assessment; those lost to follow-up attended 6.46 appointments on average (SD 4.80). The primary outcome favoured patients in the blended contract group. Extractions and fillings were more frequent in this group. Blended contracts were financially attractive for the dental provider but carried a higher cost for the service commissioner. Differences in generic health-related quality of life were negligible. Positive changes over time in oral health-related quality of life in both groups were statistically significant. This is the first UK study to assess the clinical and cost-effectiveness of a blended contract in primary care dentistry. Although the primary outcome favoured the blended contract, the results are limited because 47% patients did not attend at 24 months. This is consistent with 39% of adults not being regular attenders and 27% only visiting their dentist when they have a problem. Promotion of appropriate attendance, especially among those with high need

Oral and Dental Health Status among Adolescents with Limited Access to Dental Care Services in Jeddah.

PubMed

Bahannan, Salma A; Eltelety, Somaya M; Hassan, Mona H; Ibrahim, Suzan S; Amer, Hala A; El Meligy, Omar A; Al-Johani, Khalid A; Kayal, Rayyan A; Mokeem, Abeer A; Qutob, Akram F; Mira, Abdulghani I

2018-05-17

The purpose of this study was to assess the prevalence and associated factors of dental caries and periodontal diseases among 14⁻19-year-old schoolchildren with limited access to dental care services. A cross sectional study design was conducted during field visits to seven governmental schools in Al-Khomrah district, South Jeddah, over the period from September 2015 to May 2016. Clinical examinations and administered questionnaires were carried out in mobile dental clinics. The dentists carried out oral examinations using the dental caries index (DMFT), the simplified oral hygiene index (OHI-S), and the community periodontal index for treatment needs (CPITN). Statistical analyses were performed using SPSS 20. A total of 734 schoolchildren were examined. The prevalence of decayed teeth was 79.7% and was significantly higher among boys (88.9%) than girls (69.0%). About 11% of students had missing teeth, with a significantly higher figure among females than males (15.9% versus 7.3%); 19.8% of students had filled teeth. Moreover, a DMFT of seven or more was significantly more prevalent among males (43.3%) than females (26.8%), while the percentage of females with sound teeth was significantly higher than for males (20.4% and 9.6% respectively). The CPITN revealed 0, 1 and 2 scores among 14.6%, 78.2%, and 41.6% respectively. Males had a significantly higher percentage of healthy periodontal condition (23.8%) than females (3.8%). Dental caries prevalence was moderate to high, calculus and gingival bleeding were widespread among schoolchildren, and were more prevalent among students with low socioeconomic status.

Caregiver's education level and child's dental caries in African Americans: A path analytic study

PubMed Central

Heima, Masahiro; Lee, Wonik; Milgrom, Peter; Nelson, Suchitra

2015-01-01

The objective of this study was to investigate the influence of caregiver education level on children's dental caries mediated by both caregiver and child oral health behaviors. Participants were 423 low-income African American kindergarteners and their caregivers who were part of a school-based randomized clinical trial. Path analysis tested the hypothesis that caregiver education level affected untreated dental caries and cumulative overall caries experience (decayed or filled teeth) through the mediating influence of frequency of dental visits, use of routine care, and frequency of toothbrushing for both caregiver and child. The results supported the hypothesis: Caregivers who completed high school were 1.76 times more likely to visit dentists themselves compared with those who did not complete high school (e0.56=1.76, 95%CI: 1.03-2.99), which in turn was associated with 5.78 times greater odds of dental visits among their children (e1.76=5.78, 95%CI: 3.53-9.48). Children's dental visits, subsequently, were associated with 26% fewer untreated decayed teeth compared with children without dental visits (e-0.31=0.74, 95%CI: 0.60-0.91). However, this path was not present in the model with overall caries experience. Additionally, caregiver education level was directly associated with 34% less untreated decayed teeth (e-0.42=0.66, 95% CI: 0.54-0.79) and 28% less decayed or filled teeth (e-0.32=0.72, 95%CI: 0.60-0.88) among the children. This study overcomes important conceptual and analytic limitations in the existing literature. The findings confirm the role of caregiver education in child dental caries and indicate that caregiver's behavioral factors are important mediators of child oral health. PMID:25661111

Bisphenol A and Related Compounds in Dental Materials

PubMed Central

Fleisch, Abby F.; Sheffield, Perry E.; Chinn, Courtney; Edelstein, Burton L.; Landrigan, Philip J.

2014-01-01

CONTEXT Dental sealants and composite filling materials containing bisphenol A (BPA) derivatives are increasingly used in childhood dentistry. Evidence is accumulating that BPA and some BPA derivatives can pose health risks attributable to their endocrine-disrupting, estrogenic properties. OBJECTIVES To systematically compile and critically evaluate the literature characterizing BPA content of dental materials; to assess BPA exposures from dental materials and potential health risks; and to develop evidence-based guidance for reducing BPA exposures while promoting oral health. METHODS The extant toxicological literature and material safety data sheets were used as data sources. RESULTS BPA is released from dental resins through salivary enzymatic hydrolysis of BPA derivatives, and BPA is detectable in saliva for up to 3 hours after resin placement. The quantity and duration of systemic BPA absorption is not clear from the available data. Dental products containing the bisphenol A derivative glycidyl dimethacrylate (bis-GMA) are less likely to be hydrolyzed to BPA and have less estrogenicity than those containing bisphenol A dimethacrylate (bis-DMA). Most other BPA derivatives used in dental materials have not been evaluated for estrogenicity. BPA exposure can be reduced by cleaning and rinsing surfaces of sealants and composites immediately after placement. CONCLUSIONS On the basis of the proven benefits of resin-based dental materials and the brevity of BPA exposure, we recommend continued use with strict adherence to precautionary application techniques. Use of these materials should be minimized during pregnancy whenever possible. Manufacturers should be required to report complete information on the chemical composition of dental products and encouraged to develop materials with less estrogenic potential. PMID:20819896

Dental sealants and flowable composite restorations and psychosocial, neuropsychological, and physical development in children.

PubMed

Maserejian, Nancy N; Shrader, Peter; Trachtenberg, Felicia L; Hauser, Russ; Bellinger, David C; Tavares, Mary

2014-01-01

Dental sealant materials may intraorally release their components, including bisphenol-A (BPA), but long-term health effects are uncertain. The New England Children's Amalgam Trial (NECAT) found that composite restorations were associated with psychosocial, but not neuropsychological or physical, outcomes. The previous analysis did not consider sealants and preventive resin restorations (PRRs), which were routinely placed. The purpose of this analysis was to examine sealant/PRR exposure in association with psychosocial and other health outcomes. NECAT recruited 534 six- to 10-year-olds and provided dental care during a five-year follow-up. Annually, examiners conducted psychosocial and neuropsychological tests and measured body mass index (BMI) and fat percentage (BF%). Associations between surface years (SY) of sealants/PRRs and outcomes were tested using multivariable models. Cumulative exposure level to sealants and/or PRRs was not associated with psychosocial assessments (eg, total problems: Child Behavior Checklist, 10-SY β=-0.2 ± 0.3, P=.60) or neuropsychological tests (eg, full-scale IQ, 10-SY β=0.1 ± 0.2, P=.60). There were no associations for changes in BMI-for-age z-score (P=.40), BF% (girls 10-SY β=-0.2 ± 0.3; boys 10-SY β=-0.1 ± 0.3), or menarche (10-SY hazard ratio=0.91, 95% confidence interval=0.83-1.01, P=.08). This study showed no associations between exposure level of dental sealants or PRRs and behavioral, neuropsychological, or physical development in children over 5-years.

When Old and New Regionalism Collide: Deinstitutionalization of Regions and Resistance Identity in Municipality Amalgamations

ERIC Educational Resources Information Center

Zimmerbauer, Kaj; Paasi, Anssi

2013-01-01

Regions as well as their identities and borders are social and discursive constructs that are produced and removed in contested, historically contingent and context-bound processes of institutionalization and deinstitutionalization. This article studies the deinstitutionalization of regions in the context of municipality amalgamations and the…

Relationship between dietary intake and dental caries in preschool children.

PubMed

Yen, Chin-En; Huang, Yi-Chia; Hu, Suh-Woan

2010-06-01

This study assessed the relationship between intake of nutrients and dental caries in preschool children. One hundred and eighty-two children aged three to six years were recruited from nine day care centers in central Taiwan. These children had an oral health examination, and their parents or guardians answered a questionnaire. Each child's intake of nutrients was estimated using the 24-hour dietary recall and food frequency questionnaire data. Logistic regression analysis was applied to assess the associations between dental caries and intake of each nutrient or food group, with adjustment for potential confounders. The prevalence of dental caries was 73 % and increased with age. Not being a first-born and having more between-meal snacks were associated with increased caries risk. After controlling for other important factors, vitamin A intake was significantly associated with fewer dental caries (deft, decayed, indicated for extraction, and filled primary teeth: ≥ 4 vs. < 4), with an odds ratio of 0.97 (95 % confidence interval: 0.94 - 0.99) for an 100-μg increase in vitamin A intake. There was no significant association between dental caries and energy, macronutrient intake, and Ca/P ratio, respectively. Vegetable intake was also significantly associated with lower dental caries score.

Which maternal personality traits affect child behaviour during dental treatment.

PubMed

Arpaci, A H; Işik, B; Cura, N; Kaplan, B; Bozkurt, P

2016-09-01

Maternal personality traits affect child dental behaviour and have a potential link with dental treatment methods. This study aims to evaluate which maternal personality traits affect child dental behaviour. Research was carried out upon 60 children aged between 3-12 years, who had been admitted to our clinic for tooth extraction. All children were evaluated by means of the Frankl Behavior Scale (FBS): degrees I and II represent negative behaviours, while III and IV positive behaviour. Thirty children with FBS degree III and IV were assigned to Group I and 30 children with FBS degree I and II were assigned to Group II. Children in Group I underwent tooth extraction with local anaesthesia. Children in Group II underwent tooth extraction under deep sedation. During the first visit, the mothers were tested with the Minnesota Multiphasic Personality Inventory to evaluate personality traits. All mothers in Group I and half the mothers in Group II filled a complete and valid test. Group I and II mothers were compared according to the test results: scores of the Minnesota Multiphasic Personality Inventory (MMPI) test were significantly higher in Group II (p<0.05). We hypotetise that character features of mothers of children with negative dental behaviour and positive dental behaviour are different and affect child dental behaviour.

Levels of career satisfaction amongst dental healthcare professionals: comparison of dental therapists, dental hygienists and dental practitioners.

PubMed

Newton, J T; Gibbons, D E

2001-09-01

To compare the levels of career satisfaction expressed by three professional groups working in dental health: dental therapists, dental hygienists and dental practitioners. Level of career satisfaction was assessed using a ten point scale in three surveys. Postal surveys were conducted of all dental therapists and dental hygienists registered with the General Dental Council. Data for dental practitioners were collected as part of the British Dental Association Omnibus Survey 2000. Data are reported for 227 dental therapists, 2,251 dental hygienists and 970 dental practitioners. Significant differences were found between groups in the level of career satisfaction expressed. Dental practitioners were less likely to express high levels of satisfaction in comparison with the other two professional groups. Within each group characteristics of the respondents were associated with satisfaction levels. Younger dental therapists and dental hygienists expressed lower levels of career satisfaction. The level of career satisfaction expressed by dental practitioners was associated with gender, place of work (North vs South UK), year of qualification, size of practice and system of remuneration. Dental practitioners express lower levels of job satisfaction in comparison to other groups of dental health care professionals. Job dissatisfaction among dental practitioners is related to a number of socio-demographic factors.

Dental hyponatraemia.

PubMed

Simpson, R M

2011-08-01

A 14-year-old girl developed dental pain and was treated for acute infected pulpitis of her right upper lateral incisor with drilling and filling. The pain continued and was helped by analgesia, sucking ice cubes and drinking cold water. Forty-eight hours later, she became confused and disoriented. She started to vomit and complained of headache. Investigations revealed hyponatraemia with normal serum potassium levels and initially normal urinary sodium excretion. Over the next 24 hours, she passed 5.45 L of urine and her serum sodium rose from 125 to 143 mmol/L. Self-induced water intoxication has been described during drinking games and initiation ceremonies, but this would appear to an unusual cause. Conservative management proved successful in allowing this girl to recover without sequelae.

Equity in children's dental caries before and after cessation of community water fluoridation: differential impact by dental insurance status and geographic material deprivation.

PubMed

McLaren, Lindsay; McNeil, Deborah A; Potestio, Melissa; Patterson, Steve; Thawer, Salima; Faris, Peter; Shi, Congshi; Shwart, Luke

2016-02-11

One of the main arguments made in favor of community water fluoridation is that it is equitable in its impact on dental caries (i.e., helps to offset inequities in dental caries). Although an equitable effect of fluoridation has been demonstrated in cross-sectional studies, it has not been studied in the context of cessation of community water fluoridation (CWF). The objective of this study was to compare the socio-economic patterns of children's dental caries (tooth decay) in Calgary, Canada, in 2009/10 when CWF was in place, and in 2013/14, after it had been discontinued. We analyzed data from population-based samples of schoolchildren (grade 2) in 2009/10 and 2013/14. Data on dental caries (decayed, missing, and filled primary and permanent teeth) were gathered via open mouth exams conducted in schools by registered dental hygienists. We examined the association between dental caries and 1) presence/absence of dental insurance and 2) small area index of material deprivation, using Poisson (zero-inflated) and logistic regression, for both time points separately. For small-area material deprivation at each time point, we also computed the concentration index of inequality for each outcome variable. Statistically significant inequities by dental insurance status and by small area material deprivation were more apparent in 2013/14 than in 2009/10. Results are consistent with increasing inequities in dental caries following cessation of CWF. However, further research is needed to 1) confirm the effects in a study that includes a comparison community, and 2) explore possible alternative reasons for the findings, including changes in treatment and preventive programming.

Dental caries among disabled individuals attending special schools in Vhembe district, South Africa.

PubMed

Nemutandani, M S; Adedoja, D; Nevhuhlwi, D

2013-11-01

To determine the prevalence of dental caries among disabled individuals attending special schools in Vhembe districts. A cross-sectional descriptive study was conducted from January to June 2012 among disabled individuals receiving special care in four specialised schools of Vhembe District. The research protocol had been approved by the Ethics Committee of the University of Limpopo, Polokwane Campus. Informed consent was obtained from the parents of the participants and from the respective school principals. Oral health examinations took place at the school under natural light, with participants seated on an ordinary chair/wheelchair. Dental caries examinations were carried out, using a mirror and wooden spatula in accordance with World Health Organisation (WHO) criteria and methods. Decayed, missing and filled primary and permanent teeth (dmft, DMFT) were recorded. All disabled individuals who were available during a screening period, were included. Those who were not available, as well as those whose health conditions could be compromised by dental examinations, were excluded. The number of decayed teeth ranged from 0-7 in children below 6 years, 0-12 in children below 11 years; and 0-17 among young adults. The mean decay scores and the numbers of missing teeth increased with age. Only 3 (0.04%) individuals had dental fillings. The mean dmft score of children under 6 years was 5.51 (+/- 2.1), ranging from zero to 8. The mean DMFT's of the 11-18 and 19 years and older groups were 7.38 (+/- 3.22) and 10.24 (+/- 2.97) respectively. Disabled individuals exhibited higher caries prevalence and unmet dental needs than the same age general population in Limpopo. Preventive measures and dental treatment should be considered urgent requirements at special needs schools in the Vhembe District.

Evaluation of Radiopacity of Bulk-fill Flowable Composites Using Digital Radiography.

PubMed

Tarcin, B; Gumru, B; Peker, S; Ovecoglu, H S

2016-01-01

New flowable composites that may be bulk-filled in layers up to 4 mm are indicated as a base beneath posterior composite restorations. Sufficient radiopacity is one of the several important requirements such materials should meet. The aim of this study was to evaluate the radiopacity of bulk-fill flowable composites and to provide a comparison with conventional flowable composites using digital imaging. Ten standard specimens (5 mm in diameter, 1 mm in thickness) were prepared from each of four different bulk-fill flowable composites and nine different conventional flowable composites. Radiographs of the specimens were taken together with 1-mm-thick tooth slices and an aluminum step wedge using a digital imaging system. For the radiographic exposures, a storage phosphor plate and a dental x-ray unit at 70 kVp and 8 mA were used. The object-to-focus distance was 30 cm, and the exposure time was 0.2 seconds. The gray values of the materials were measured using the histogram function of the software available with the system, and radiopacity was calculated as the equivalent thickness of aluminum. The data were analyzed statistically (p<0.05). All of the tested bulk-fill flowable composites showed significantly higher radiopacity values in comparison with those of enamel, dentin, and most of the conventional flowable composites (p<0.05). Venus Bulk Fill (Heraeus Kulzer) provided the highest radiopacity value, whereas Arabesk Flow (Voco) showed the lowest. The order of the radiopacity values for the bulk-fill flowable composites was as follows: Venus Bulk Fill (Heraeus Kulzer) ≥ X-tra Base (Voco) > SDR (Dentsply DeTrey) ≥ Filtek Bulk Fill (3M ESPE). To conclude, the bulk-fill flowable restorative materials, which were tested in this study using digital radiography, met the minimum standard of radiopacity specified by the International Standards Organization.

SU-F-BRB-15: Dosimetric Study of Radiation Therapy for Head/Neck Patients with Metallic Dental Fixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, L; Allan, E; Putten, M Van

Purpose: To investigate the dose contributions of scattered electrons from dental amalgams during head and neck radiotherapy, and to evaluate the protective role of dosimetric dental stents during treatment to prevent oral mucositis. Methods: A phantom was produced to accurately simulate the oral cavity and head. The oral cavity consisted of a tissue equivalent upper and lower jaw and complete set of teeth. A set of 4 mm ethylene copolymer dosimetric stents was made for the upper and lower teeth. Five removable gold caps were fitted to apposing right molars, and the phantom was crafted to accomodate horizontal and verticalmore » film for 2D dosimetry and NanoDot dosimeter for recording point doses. The head was simulated using a small cylindrical glass water bath. CT simulation was performed on the phantom with and without metal fittings and, in each case, with and without the dental stent. The CT image sets were imported into Eclipse treatment planning system for contouring and treatment planning, and a 9-field IMRT treatment plan was developed for each scenario. These plans were delivered using a Varian TrueBeam linear accelerator. Doses were recorded using GafChromic EBT2 films and NanoDot dosimeters. Results: The measurements revealed a 43% relative increase in dose measured adjacent to the metal fixtures in the horizontal plane without the use of the dental stent. This equates to a total dose of 100 Gy to the oral mucosa during a standard course of definitive radiotherapy. To our knowledge, this is the first dosimetric analysis of dental stents using an anatomically realistic phantom and modern beam arrangement. Conclusion: These results support the use of dosimetric dental stents in head and neck radiotherapy for patients with metallic dental fixtures as a way to effectively reduce dose to nearby mucosal surfaces and, hence, reduce the risk and severity of mucositis.« less

Child rearing styles, dental anxiety and disruptive behaviour; an exploratory study.

PubMed

Krikken, J B; Veerkamp, J S J

2008-02-01

This was to explore the relation between children's dental anxiety, their behaviour during treatment and their parent's rearing style. Also the parents' preparation of the child for dental treatment was related to behaviour and parental rearing style. The parents of 100 children, referred to a secondary dental care clinic were asked to fill out the Child Rearing Practices Report (CRPR), the Child Fear Survey Schedule (CFSS) on behalf of their children and an additional questionnaire on child preparation prior to dental treatment. Four rearing styles were constructed by using the results of the Nurturance and the Restrictiveness domain of the CRPR. Dentists were asked to assess the behaviour of the child during dental habituation and dental treatment using the Venham scale. The dentists were unaware of the child's CFSS score. Parents were not present during actual dental treatment. Each child's dental anxiety was related to their behaviour displayed during dental treatment. Highly anxious children showed more disruptive behaviour than their low anxious counterparts did, especially during familiarisation. Parental rearing style was neither related to child dental anxiety prior to or to behaviour during dental treatment. Parents who use a permissive rearing style were less likely to tell their children that the dentist will not hurt them compared with authoritarian parents. Parents with an authoritative rearing style were more convinced that the behaviour of their child could be managed by the dentist than parents with a permissive and neglectful rearing style. After their children's dental rehabilitation parents were less inclined to accompany their child during treatment. Dental anxiety correlated positively with the behaviour displayed during treatment. No relation was found between parenting style and dental anxiety and behaviour during treatment. Parents showed more confidence in the child-dentist dyad after the rehabilitation of their child's teeth.

The relative patient costs and availability of dental services, materials and equipment in public oral care facilities in Tanzania.

PubMed

Nyamuryekung'e, Kasusu K; Lahti, Satu M; Tuominen, Risto J

2015-07-01

Patient charges and availability of dental services influence utilization of dental services. There is little available information on the cost of dental services and availability of materials and equipment in public dental facilities in Africa. This study aimed to determine the relative cost and availability of dental services, materials and equipment in public oral care facilities in Tanzania. The local factors affecting availability were also studied. A survey of all district and regional dental clinics in selected regions was conducted in 2014. A total of 28/30 facilities participated in the study. A structured interview was undertaken amongst practitioners and clinic managers within the facilities. Daily resources for consumption (DRC) were used for estimation of patients' relative cost. DRC are the quantified average financial resources required for an adult Tanzanian's overall consumption per day. Tooth extractions were found to cost four times the DRC whereas restorations were 9-10 times the DRC. Studied facilities provided tooth extractions (100%), scaling (86%), fillings (79%), root canal treatment (46%) and fabrication of removable partial dentures (32%). The ratio of tooth fillings to extractions in the facilities was 1:16. Less than 50% of the facilities had any of the investigated dental materials consistently available throughout the year, and just three facilities had all the investigated equipment functional and in use. Dental materials and equipment availability, skills of the practitioners and the cost of services all play major roles in provision and utilization of comprehensive oral care. These factors are likely to be interlinked and should be taken into consideration when studying any of the factors individually.

Dental auxiliaries for dental care traditionally provided by dentists.

PubMed

Dyer, Tom A; Brocklehurst, Paul; Glenny, Anne-Marie; Davies, Linda; Tickle, Martin; Issac, Ansy; Robinson, Peter G

2014-08-20

RCT, three RCTs and one NRCT), evaluating the effectiveness of dental auxiliaries compared with dentists in providing dental care traditionally provided by dentists, eligible for inclusion in this review. The included studies, which involved 13 dental auxiliaries, six dentists, and more than 1156 participants, evaluated two clinical tasks/techniques: placement of preventive resin fissure sealants and the atraumatic restorative technique (ART). Two studies were conducted in the US, and one each in Canada, Gambia and Singapore.Of the four studies evaluating effectiveness in placing preventive resin fissure sealants, three found no evidence of a difference in retention rates of those placed by dental auxiliaries and dentists over a range of follow-up periods (six to 24 months). One study found that fissure sealants placed by a dental auxiliary had lower retention rates than one placed by a dentist after 48 months (9.0% with auxiliary versus 29.1% with dentist). The same study reported that the net reduction after 48 months in the number teeth exhibiting caries (dental decay) was lower for teeth treated by the dental auxiliary than the dentist (3 with auxiliary versus 60 with dentist, P value < 0.001).One study showed no evidence of a difference in dental decay after treatment with fissure sealants between groups. The one study comparing the effectiveness of dental auxiliaries and dentists in performing ART reported no difference in survival rates of the restorations (fillings) after 12 months.All studies were at high risk of bias and the overall quality of the evidence was very low, as assessed using the GRADE approach. In addition, four of the included studies were more than 20 years old; the materials used and the techniques assessed were out of date. We found no eligible studies comparing the effectiveness of dental auxiliaries and dentists in the diagnosis of oral diseases and conditions, in delivering oral health education and other aspects of health promotion, or

Diagnostic accuracy of different display types in detection of recurrent caries under restorations by using CBCT.

PubMed

Baltacıoĝlu, İsmail H; Eren, Hakan; Yavuz, Yasemin; Kamburoğlu, Kıvanç

To assess the in vitro diagnostic ability of CBCT images using seven different display types in the detection of recurrent caries. Our study comprised 128 extracted human premolar and molar teeth. 8 groups each containing 16 teeth were obtained as follows: (1) Black Class I (Occlusal) amalgam filling without caries; (2) Black Class I (Occlusal) composite filling without caries; (3) Black Class II (Proximal) amalgam filling without caries; (4) Black Class II (Proximal) composite filling without caries; (5) Black Class I (Occlusal) amalgam filling with caries; (6) Black Class I (Occlusal) composite filling with caries; (7) Black Class II (Proximal) amalgam filling with caries; and (8) Black Class II (Proximal) composite filling with caries. Teeth were imaged using 100 × 90 mm field of view at three different voxel sizes of a CBCT unit (Planmeca ProMax(®) 3D ProFace™; Planmeca, Helsinki, Finland). CBCT TIFF images were opened and viewed using custom-designed software for computers on different display types. Intra- and interobserver agreements were calculated. The highest area under the receiver operating characteristic curve (Az) values for each image type, observer, reading and restoration were compared using z-tests against Az = 0.5. The significance level was set at p = 0.05. We found poor and moderate agreements. In general, Az values were found when software and medical diagnostic monitor were utilized. For Observer 2, Az values were statistically significantly higher when software was used on medical monitor [p = 0.036, p = 0.015 and p = 0.002, for normal-resolution mode (0.200 mm(3) voxel size), high-resolution mode (0.150 mm(3) voxel size) and low-resolution mode (0.400 mm(3) voxel size), respectively]. No statistically significant differences were found among other display types for all modes (p > 0.05). In general, no difference was found among 3 different voxel sizes (p > 0.05). In general, higher Az values were

Diagnostic accuracy of different display types in detection of recurrent caries under restorations by using CBCT

PubMed Central

Baltacıoĝlu, İsmail H; Eren, Hakan; Yavuz, Yasemin

2016-01-01

Objectives: To assess the in vitro diagnostic ability of CBCT images using seven different display types in the detection of recurrent caries. Methods: Our study comprised 128 extracted human premolar and molar teeth. 8 groups each containing 16 teeth were obtained as follows: (1) Black Class I (Occlusal) amalgam filling without caries; (2) Black Class I (Occlusal) composite filling without caries; (3) Black Class II (Proximal) amalgam filling without caries; (4) Black Class II (Proximal) composite filling without caries; (5) Black Class I (Occlusal) amalgam filling with caries; (6) Black Class I (Occlusal) composite filling with caries; (7) Black Class II (Proximal) amalgam filling with caries; and (8) Black Class II (Proximal) composite filling with caries. Teeth were imaged using 100 × 90 mm field of view at three different voxel sizes of a CBCT unit (Planmeca ProMax® 3D ProFace™; Planmeca, Helsinki, Finland). CBCT TIFF images were opened and viewed using custom-designed software for computers on different display types. Intra- and interobserver agreements were calculated. The highest area under the receiver operating characteristic curve (Az) values for each image type, observer, reading and restoration were compared using z-tests against Az = 0.5. The significance level was set at p = 0.05. Results: We found poor and moderate agreements. In general, Az values were found when software and medical diagnostic monitor were utilized. For Observer 2, Az values were statistically significantly higher when software was used on medical monitor [p = 0.036, p = 0.015 and p = 0.002, for normal-resolution mode (0.200 mm3 voxel size), high-resolution mode (0.150 mm3 voxel size) and low-resolution mode (0.400 mm3 voxel size), respectively]. No statistically significant differences were found among other display types for all modes (p > 0.05). In general, no difference was found among 3 different voxel sizes (p > 0.05). In general

In vitro investigation of the performance of different restorative materials under cast circumferential clasps for removable dental prostheses.

PubMed

Pospiech, Peter; Nagel, Florian; Gebhart, Florian; Nothdurft, Frank P; Mitov, Gergo

2012-12-01

The objective of this in vitro study was to investigate the behavior of different composite restorative materials under the load of cast circumferential clasps for removable dental prostheses (RDPs). In 60 human molars, standardized mesial-occlusal-distal cavities were prepared. The cavities were restored with the following materials: Definite, Tetric Ceram, SureFil, Heliomolar RO, Ariston pHc, and Oralloy, and provided with a rest seat. The rest seats were subjected to 5,000 cycles of thermal cycling and 1,200,000 masticatory cycles in a mastication simulator via cobalt-chromium circumferential clasps cast to standardized frameworks in a laboratory model designed to simulate the biomechanics of a free-end denture base. Fracture analysis of the restorations was performed by light microscopy. Before and after loading, material wear was measured with a 3D-laser scanner, and an analysis of the marginal quality was performed in an SEM at ×200 applying the replica technique. No significant differences in the fracture behavior among the composite materials were found; the amalgam control group showed a significantly higher fracture resistance. Regarding the wear of the materials, the composites Definite and SureFil exhibited a behavior similar to that of amalgam. The other composites demonstrated higher wear rates. The initial marginal quality was significantly worse for Ariston pHc. The marginal adaptation decreased significantly after thermal and mechanical loading for Definite and Ariston pHc. In terms of the investigated aspects of mechanical performance, the tested composites seemed to be inferior to amalgam. Further clinical studies are needed to evaluate the ability of composite restorations to provide support for RDP clasps. The use of composites as direct restoration materials should be avoided in teeth, which serve as abutments for clasp-retained RDPs.

Oral health status of children with special health care needs receiving dental treatment under general anesthesia at the dental clinic of Taipei Veterans General Hospital in Taiwan.

PubMed

Chen, Chia-Yu; Chen, Ya-Wei; Tsai, Tzong-Ping; Shih, Wen-Yu

2014-04-01

Oral health is crucial to individual growth and development. However, oral health care is often overlooked in children with special health care needs (CSHCN). We investigated current oral health status and unmet dental needs of CSHCN in Taiwan. We performed a retrospective study of consecutive CSHCN cases receiving first-time comprehensive dental treatment under general anesthesia at Taipei Veterans General hospital from 2001 to 2010. We retrieved clinical data including age, sex, types, and severity of disability, caries experience index [decayed, extracted, and filled teeth (deft) index for primary dentition/decayed, missing, and filled teeth (DMFT) index for permanent dentition], malocclusion, and treatment modalities from medical charts for analysis. The correlation between different groups of CSHCN regarding the deft/DMFT indices and treatment modalities was analyzed statistically. Our study included 96 children, ranging in age from 2.4 years to 14.3 years (mean age 6.8 ± 3.3 years). The deft/DMFT index was significantly higher in the younger age group (2-6 years; 13.8 ± 4.3) compared with the older group (> 6 years; 10.5 ± 5.3; p < 0.001). The mean number of total treated teeth was 14.2 ± 3.8, and no differences existed among disability groups (p = 0.528) and age groups (p = 0.992). For the treatment modality, the number of pulp therapies with crown restoration was higher in the younger age group than in the older group. At the time of the study, 53 CSHCN had reached their full permanent dentition. We observed significantly more malocclusion of full permanent dentition in the older age group (91%) than in the younger group (35%; p < 0.001). Unmet dental needs and caries experience indices remain high in CSHCN, regardless of the types and severity of disability. However, the younger the age at which CSHCN received their first dental treatment, the more effective the dental rehabilitation was. Parental education regarding early dental intervention and a

Algorithm of first-aid management of dental trauma for medics and corpsmen.

PubMed

Zadik, Yehuda

2008-12-01

In order to fill the discrepancy between the necessity of providing prompt and proper treatment to dental trauma patients, and the inadequate knowledge among medics and corpsmen, as well as the lack of instructions in first-aid textbook and manuals, and after reviewing the dental literature, a simple algorithm for non-professional first-aid management for various injuries to hard (teeth) and soft oral tissues, is presented. The recommended management of tooth avulsion, subluxation and luxation, crown fracture and lip, tongue or gingival laceration included in the algorithm. Along with a list of after-hour dental clinics, this symptoms- and clinical-appearance-based algorithm is suited to tuck easily into a pocket for quick utilization by medics/corpsmen in an emergency situation. Although the algorithm was developed for the usage of military non-dental health-care providers, this method could be adjusted and employed in the civilian environment as well.

Oral Health Status and Behaviour of Mauritians Visiting Private Dental Clinics

ERIC Educational Resources Information Center

Gunsam, P. Pugo; Banka, S.

2011-01-01

Purpose: This paper seeks to assess the oral health status and behaviour of a sample of the Mauritian population visiting private dental clinics. Design/methodology/approach: Oral health status was determined using the World Health Organization (Decayed, Missing, Filled Teeth (DMFT) index indicating the prevalence of caries, and factors associated…

An Empirical Consideration of a Balanced Amalgamation of Learning Strategies in Graduate Introductory Statistics Classes

ERIC Educational Resources Information Center

Vaughn, Brandon K.

2009-01-01

This study considers the effectiveness of a "balanced amalgamated" approach to teaching graduate level introductory statistics. Although some research stresses replacing traditional lectures with more active learning methods, the approach of this study is to combine effective lecturing with active learning and team projects. The results of this…