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About Correa L, Rea LD, Bentzen R, O’Hara TM.

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So far Correa L, Rea LD, Bentzen R, O’Hara TM. has created 996 blog entries.

Assessment of mercury and selenium tissular concentrations and total mercury body burden in 6 Steller sea lion pups from the Aleutian Islands

Concentrations of total mercury ([THg]) and selenium ([TSe]) were measured in several tissue compartments in Steller sea lion (Eumetopias jubatus) pups; in addition we determined specific compartment and body burdens of THg. Compartmental and body burdens were calculated by multiplying specific compartment fresh weight by the [THg] (summing compartment burdens equals body burden). In all 6 pup tissue sets (1) highest [THg] was in hair, (2) lowest [THg] was in bone, and (3) pelt, muscle and liver burdens contributed the top three highest percentages of THg body burden. In 5 of 6 pups the Se:Hg molar ratios among compartments ranged from 0.9 to 43.0. The pup with the highest hair [THg] had Se:Hg molar ratios in 9 of 14 compartments that were ⩽ 0.7 potentially indicating an inadequate [TSe] relative to [THg]

By |2020-12-17T23:58:51+00:00January 1st, 2014|Mercury|

High-power lasers in endodontics–fiber placement for laser enhanced endodontics: in the canal or at the orifice.

The aim of this review is to give a survey of the use of high-power lasers for root canal cleaning and disinfection. There are two approaches: the first using a fiber in a dry root canal and exposing the root canal wall to the laser light with a spiral motion, and the other using the fiber in irrigant in the root canal or at the orifice. The laser-target interaction is different: a direct exposure of the substrate to laser light is the aim of the spiral motion, whereas the aim of the second technique is activation and agitation of the irrigant (laser activated irrigation / LAI). A limitation of the fiber is the straight forward emission. Modification of the fiber tip into a more conical shape allows for more lateral emission. This modification, however, does not result in far better cleaning and disinfection. Taking into account that all irrigants are water-based solutions, it is possible to create cavitation bubbles and to induce shockwaves and agitation in the irrigant with Erbium lasers. The newer technology allows for the use of low energy during a very short exposure time, resulting in high peak powers. Investigations on the latter topic have demonstrated that the creation of cavitation resulting in the induction of liquid agitation and shock waves in the irrigant may result in an in-depth cleaning and disinfection. Erbium lasers are the first choice for the activation of endodontic irrigants. Research in this respect has demonstrated that LAI performs “equal to” or “better than” ultrasonic activation. Other wavelengths with a solid absorption in water are now to be explored

By |2019-05-28T21:59:07+00:00January 1st, 2014|Other|

Microorganism penetration in dentinal tubules of instrumented and retreated root canal walls.

OBJECTIVES:

This in vitro study aimed to investigate the ability of Candida albicans (C. albicans) and Enterococcus faecalis (E. faecalis) to penetrate dentinal tubules of instrumented and retreated root canal surface of split human teeth.

MATERIALS AND METHODS:

Sixty intact extracted human single-rooted teeth were divided into 4 groups, negative control, positive control without canal instrumentation, instrumented, and retreated. Root canals in the instrumented group were enlarged with endodontic instruments, while root canals in the retreated group were enlarged, filled, and then removed the canal filling materials. The teeth were split longitudinally after canal preparation in 3 groups except the negative control group. The teeth were inoculated with both microorganisms separately and in combination. Teeth specimens were examined by scanning electron microscopy (SEM), and the depth of penetration into the dentinal tubules was assessed using the SMILE view software (JEOL Ltd).

RESULTS:

Penetration of C. albicans and E. faecalis into the dentinal tubules was observed in all 3 groups, although penetration was partially restricted by dentin debris of tubules in the instrumented group and remnants of canal filling materials in the retreated group. In all 3 groups, E. faecalis penetrated deeper into the dentinal tubules by way of cell division than C. albicans which built colonies and penetrated by means of hyphae.

CONCLUSIONS:

Microorganisms can easily penetrate dentinal tubules of root canals with different appearance based on the microorganism size and status of dentinal tubules.

Validation of dental X-ray by cytokine RANTES–comparison of X-ray findings with cytokine overexpression in jawbone.

INTRODUCTION:

There is a need to clarify the extent to which the most common diagnostic tool in dentistry – two-dimensional panoramic tomography (2D-OPG) – is suitable for identifying fatty degenerative osteolysis of jawbone (FDOJ).

MATERIALS AND METHODS:

To obtain a qualitative assessment of edentulous jawbone sections, the results from 2D-OPG with a defined X-ray density (XrDn), expression of the cytokine RANTES (regulated on activation, normal T-cell expressed and secreted), and a transalveolar ultrasound system for measuring jawbone density were compared.

RESULTS:

The difference in the XrDn of healthy jawbone and FDOJ are minimal, whereas RANTES is up to 25-fold higher in FDOJ. In contrast to 2D-OPG, transalveolar ultrasound showed coincidental findings in FDOJ areas.

DISCUSSION:

Comparisons of the data revealed a discrepancy between the XrDn of 2D-OPGs and the medullary osteopathies in the jawbone like FDOJ.

CONCLUSION:

The data suggest that there is a critical attitude toward the use of 2D-OPG as a sole imaging diagnostic tool for assessing chronic inflammatory processes in the jawbone. Specifically, 2D-OPG is objectively not suitable for depicting FDOJ.

KEYWORDS:

RANTES; bone density measurement; osteonecrotic jawbone; silent inflammation

By |2019-01-05T21:41:53+00:00January 1st, 2014|Periodontal Disease|

Metals as a common trigger of inflammation resulting in non-specific symptoms: diagnosis and treatment.

BACKGROUND:
The multiple symptoms of chronic fatigue syndrome (CFS) and fibromyalgia resemble those described in patients suffering from autoimmune/inflammatory syndrome induced by adjuvants (ASIA). It has been suggested that chronic metal-induced inflammation might play a role both in CFS and fibromyalgia as well as in ASIA. Humans are exposed to metals mainly through the release of metal ions from corroding dental restorations and orthopedic implants, food, vaccines and jewelry. Metals readily bind to sulphur and other groups in the mitochondria, enzymes and cell proteins. Metal-bound proteins are recognized by the immune system of susceptible subjects and might trigger an abnormal immune response, including allergy and autoimmunity.

OBJECTIVES:
To study three subjects with CFS and two with fibromyalgia, all of whom suspected metal exposure as a trigger for their ill health.

METHODS:
We measured delayed-type hypersensitivity to metals (metal allergy) using a validated lymphocyte transformation test, LTT-MELISA. All patients except one were sensitized to metals present in their dental restorations. The remaining patient reacted to metals in his skull implant. The removal of sensitizing metals resulted in long-term health improvement. Nine healthy controls matched for gender and age showed only marginal reactivity to the metals tested.

CONCLUSIONS:
Patients with CFS and fibromyalgia are frequently sensitized to metals found in the environment or used in dentistry and surgery. This allergy to metals might initiate or aggravate non-specific symptoms in metal-sensitized patients.

By |2018-07-31T20:46:34+00:00January 1st, 2014|Mercury, Other|

Marketing strategies and warning labels on children’s toothpaste.

The overconsumption of toothpaste has negative consequences, particularly for children. This study’s objectives were to describe misleading marketing strategies used in selling children’s fluoridated toothpaste and identify warning label characteristics. Two researchers independently coded the packaging from 26 over-the-counter toothpastes that are specifically marketed for children. Aggressive marketing strategies targeting children were identified: every toothpaste in this sample displayed at least 1 children’s animated character, 50% had at least 1 picture of a food item, 92.3% stated they were flavored and 26.9% depicted a full swirl of toothpaste, directly contradicting dentist recommendations for young children. Further, on most toothpaste tubes, warnings regarding fluoride overconsumption for young children were only listed on the back and in very small font. Misleading marketing strategies are regularly used in selling children’s toothpaste as if it is a food product, while warnings regarding overconsumption among youth are minimized. Dental hygienists are in an important position to help parents of young children implement safe oral care practices.

By |2018-07-18T19:57:04+00:00January 1st, 2014|Fluoride|

Hypersensitivity reactions to titanium: diagnosis and management.

Titanium is notable for its biocompatibility and is used as biologic implant material across surgical specialties, especially in metal-sensitive individuals. However, rare cases of titanium hypersensitivity reactions are reported in the literature. This article discusses the properties and biological behavior of titanium and provides a thorough review of the literature on reported cases, diagnostic techniques, and approach to management of titanium hypersensitivity.

By |2018-08-03T18:55:56+00:00January 1st, 2014|Other|

Focus on fluorides: update on the use of fluoride for the prevention of dental caries.

BACKGROUND:
Fluoride is delivered to the teeth systemically or topically to aid in the prevention of dental caries. Systemic fluoride from ingested sources is in blood serum and can be deposited only in teeth that are forming in children. Topical fluoride is from sources such as community water, processed foods, beverages, toothpastes, mouthrinses, gels, foams, and varnishes. The United States Centers for Disease Control and Prevention (CDC) and the American Dental Association (ADA) have proposed changes in their long standing recommendations for the amount of fluoride in community drinking water in response to concerns about an increasing incidence of dental fluorosis in children. Current research is focused on the development of strategies to improve fluoride efficacy. The purpose of this update is to inform the reader about new research and policies related to the use of fluoride for the prevention of dental caries.

METHODS:
Reviews of the current research and recent evidence based systematic reviews on the topics of fluoride are presented. Topics discussed include: updates on community water fluoridation research and policies; available fluoride in dentifrices; fluoride varnish compositions, use, and recommendations; and other fluoride containing dental products. This update provides insights into current research and discusses proposed policy changes for the use of fluoride for the prevention of dental caries.

CONCLUSIONS:
The dental profession is adjusting their recommendations for fluoride use based on current observations of the halo effect and subsequent outcomes. The research community is focused on improving the efficacy of fluoride therapies thus reducing dental caries and lowering the amount of fluoride required for efficacy.

By |2018-07-19T18:32:44+00:00January 1st, 2014|Fluoride|

Uptake of environmental toxicants by the locus ceruleus: a potential trigger for neurodegenerative, demyelinating and psychiatric disorders.

This hypothesis proposes that environmental toxicants entering the locus ceruleus can give rise to a variety of CNS disorders. Proposals are made for experiments to gain further evidence for this hypothesis. If it is shown that toxicants in the locus ceruleus are responsible for these conditions, attempts can be made to prevent the toxicant exposures or to remove the toxicants from the nervous system.

By |2018-07-27T18:30:01+00:00January 1st, 2014|Mercury|

Effect of fluoridated sealants on adjacent tooth surfaces: A 30-mo randomized clinical trial.

A double-blind randomized clinical trial was performed in 6- to 7-yr-old schoolchildren to evaluate, in a 30-mo period, whether the caries increment on the distal surface of the second primary molars adjacent to permanent first molars sealed with fluoride release compounds would be lower with respect to those adjacent to permanent first molars sealed with a nonfluoridated sealant. In sum, 2,776 subjects were enrolled and randomly divided into 3 groups receiving sealants on sound first molars: high-viscosity glass ionomer cement (GIC group); resin-based sealant with fluoride (fluoride-RB group); and a resin-based sealant without fluoride (RB group). Caries (D1 – D3 level) was recorded on the distal surface of the second primary molar, considered the unit of analysis including only sound surfaces at the baseline. At baseline, no differences in caries prevalence were recorded in the 3 groups regarding the considered surfaces. At follow-up, the prevalence of an affected unit of analysis was statistically lower (p = .03) in the GIC and fluoride-RB groups (p = .04). In the GIC group, fewer new caries were observed in the unit of analysis respect to the other 2 groups. Incidence rate ratios (IRRs) were 0.70 (95% confidence interval: 0.50, 0.86; p < .01) for GIC vs. RB and 0.79 (95% confidence interval: 0.67, 0.89; p = .005) for fluoride-RB vs. RB [Corrected]. Caries incidence was significantly associated with low socioeconomic status (IRR = 1.18; 95% confidence interval: 1.10, 1.42; p = .05). Dental sealant high-viscosity GIC and fluoride-RB demonstrated protection against dental caries, and there was evidence that these materials afforded additional protection for the tooth nearest to the sealed tooth (clinical trial registration NCT01588210).

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