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Corticosteroid enhances the experimental induction of osteonecrosis in rabbits with Shwartzman reaction.

Bacterial endotoxic reactions can cause osteonecrosis in humans by disseminated intravascular coagulation. The authors first used a combination of the Shwartzman reaction and corticoid injections in rabbits to develop a new animal model of osteonecrosis. This model showed a significantly higher incidence and wider area of osteonecrosis in the femur and humerus than that found in rabbits with either Shwartzman reaction or steroid injection alone. Osteonecrosis was observed in several foci that were distributed from the diaphysis to the epiphysis in both bones. Histologically, the bone marrow cells underwent necrosis, whereas the bone trabeculae demonstrated either empty lacunae or pycnotic nuclei of osteocytes. Exogenous steroids appeared to potentiate the Shwartzman reaction and the magnitude of osteonecrosis, perhaps by increasing endothelial damage and hypercoagulability of those intraosseous and extraosseous vessels that subsequently thrombosed. This model may not only be useful in clarifying the etiology and early pathogenesis of human osteonecrosis after corticoid therapy, but also in designing pharmaceuticals for prevention and early treatment.

By Yamamoto T, Hirano K, Tsutsui H, Sugioka Y, Sueishi K.|2018-09-01T01:32:02+00:00January 1st, 1995|Other|

Evidence that mercury from silver dental fillings may be an etilological factor in multiple sclerosis.

This paper investigates the hypothesis that mercury from silver dental fillings (amalgam) may be related to multiple sclerosis (MS). It compares blood findings between MS subjects who had their amalgams removed to MS subjects with amalgams. MS subjects with amalgams were found to have significantly lower levels of red blood cells, hemoglobin and hematocrit compared to MS subjects with amalgam removal. Thyroxine levels were also significantly lower in the MS amalgam group and they had significantly lower levels of total T Lymphocytes and T-8 (CD8) suppressor cells. The MS amalgam group had significantly higher blood urea nitrogen and lower serum IgG. Hair mercury was significantly higher in the MS subjects compared to the non-MS control group. A health questionnaire found that MS subjects with amalgams had significantly more (33.7%) exacerbations during the past 12 months compared to the MS volunteers with amalgam removal. The paper also examines epidemiological correlations between dental caries and MS; as well as how mercury could be causing the pathological and physiological changes found in multiple sclerosis.

By Siblerud RL, Kienholz E.|2020-03-30T23:46:36+00:00January 1st, 1994|Mercury|

Impact of artificial fluoridation on salmon species in the northwest USA and British Columbia, Canada.

A review of literature and documentation suggests that concentrations of fluoride above 0.2 mg/L have lethal (LC50) effects on and inhibit migration of “endangered” salmon species whose stocks are now in serious decline in the US Northwest and British Columbia. Fluoride added to drinking water,”to improve dental health”, enters the fresh water eco-system, in various ways, at levels above 0.2 mg/L. This factor, if considered in “critical habitat” decisions, should lead to the development of a strategy calling for a ban on fluoridation and rapid sunsetting of the practice of disposal of industrial fluoride waste into fresh water.

By Foulkes RG, Anderson AC.|2018-07-20T21:26:33+00:00January 1st, 1994|Fluoride|

The beginning of oral pathology: Part I: First dental journal reports of odontogenic tumors and cysts, 1839–1860.

Literature reviews of oral lesions frequently lack an appropriate historic perspective, presuming that the mid- to late-twentieth century reports are the first valid reports available. The mid-nineteenth century dental journals, however, are replete with clinical, surgical, and microscopic descriptions of oral tumors and cysts. Most of these have never been referenced during the present century. The purpose of this article is to report the earliest dental journal references for a variety of odontogenic tumors and cysts. These references are derived from a canvass of all dental journals published from the first journal (American Journal of Dental Science) in 1839 to the appearance of Dental Cosmos and the organization of the American Dental Association in 1860.

By Bouquot JE, Lense EC.|2018-08-24T21:23:29+00:00January 1st, 1994|Periodontal Disease|

The effect of acid and fluoride release on the antimicrobial properties of four glass ionomer cements.

Glass ionomer cements reportedly bond to tooth surfaces by physicochemical interaction and slowly release fluoride. 1 Two mechanisms are involved in fluoride release, a rapid surface elution and a slower bulk diffusion of fluoride ions. 2, 3 The greatest release of fluoride reportedly occurs in the first 24 hr, and then remains constant for several months before it tapers off after 2 years.4, 5 Such slow release of fluoride from silicate cements has been shown to have an anticariogenic effect.6, 7 dependent primarily on the longevity of the release.8 Recent research also has reported an antimicrobial effect of glass ionomer cements in vitro 9 and in vivo.10, 11 The objectives of our in vitro experiments were to determine the fluoride and acid release of several glass ionomer cements over time, and the relationship of the fluoride and acid to the antibacterial effects of these cements. (Pediatr Dent 16: 1994)

By Fischman SA, Tinanoff N.|2018-07-20T21:04:40+00:00January 1st, 1994|Fluoride|

Reduction in operatory mercury levels after contamination or amalgam removal.

The threshold limit value (TLV) for occupational exposure to mercury can be exceeded in the dental operatory after a contamination event or during certain dental procedures. The objective of this study was to determine the time required for the mercury vapor levels to return to baseline in both non-ventilated and ventilated operatories after they had been contaminated with mercury to the TLV of 0.050 mg/m3; and to evaluate the efficiency of an activated charcoal filtering device for removing mercury vapor. The results showed that even in a poorly ventilated operatory, the mercury vapor level returned to background within 20-30 minutes after a contamination, and within 10-20 minutes when the operatory was ventilated. The filtering device reduced the level of mercury vapor by approximately 25% during a continuous contamination event, but did not clear the operatory faster than normal settling after a limited source contamination. The filter caused a significant reduction in mercury in the breathing zones of the patient and dentist during and after amalgam removal, but did not eliminate the exposure. This study demonstrated the difficulty in contaminating an operatory with mercury vapor and confirmed the limited time mercury remains airborne, presumably due to its density and affinity for surfaces.

By Ferracane JL, Engle JH, Okabe T, Mitchem JC.|2018-07-20T20:39:22+00:00January 1st, 1994|Mercury|

Case report: Mass fluoride poisoning, Hooper Bay, Alaska.

The death of a 41-year-old male and the illness of approximately 296 others on May 21-23, 1992, in Hooper Bay Alaska has been shown to be due to acute fluoride intoxication caused by malfunction of the fluoridation equipment of system 1 of the village’s two-system (well) water supply. Fluoride levels were reported to be as high as 150 ppm.

By Foulkes RG.|2019-06-25T19:38:31+00:00January 1st, 1994|Fluoride|

Value of epicutaneous patch testing in patients with oral, mucosal lesions of lichenoid character. .

The purpose of the present investigation was to determine, in patients with oral mucosal lesions of lichenoid character, whether it is possible with epicutaneous patch tests, to detect those who will react favorably to removal of amalgam. Of 48 patients, 19 (39.6%) showed positive patch test reactions to 1% mercury ammonium chloride, and 29 (60.4%) showed negative test results. The observation period varied from 3 months to 3 yr (mean value 1.5 yr). After treatment, 94.7% of the positive group and 86.2% of the negative group showed regression of lesions. Reactions exceeding the contact zone between amalgam restorations and lesions showed positive patch test results in 21% of the cases, as compared with 47% among those with lesions restricted to the contact areas; 85.7 and 93.9%, respectively, showed regression after removal of amalgam restorations. The results of the present study indicate that removal of amalgam usually affects the lesions favorably and that epicutaneous patch tests are of little prognostic value in patients with oral mucosal lesions of lichenoid character.

By Skoglund A.|2018-07-31T16:15:44+00:00January 1st, 1994|Mercury|

Acute fluoride poisoning from a public water system

BACKGROUND:

Acute fluoride poisoning produces a clinical syndrome characterized by nausea, vomiting, diarrhea, abdominal pain, and paresthesias. In May 1992, excess fluoride in one of two public water systems serving a village in Alaska caused an outbreak of acute fluoride poisoning.

METHODS:

We surveyed residents, measured their urinary fluoride concentrations, and analyzed their serum-chemistry profiles. A case of fluoride poisoning was defined as an illness consisting of nausea, vomiting, diarrhea, abdominal pain, or numbness or tingling of the face or extremities that began between May 21 and 23.

RESULTS:

Among 47 residents studied who drank water obtained on May 21, 22, or 23 from the implicated well, 43 (91 percent) had an illness that met the case definition, as compared with only 6 of 21 residents (29 percent) who drank water obtained from the implicated well at other times and 2 of 94 residents (2 percent) served by the other water system. We estimated that 296 people were poisoned; 1 person died. Four to five days after the outbreak, 10 of the 25 case patients who were tested, but none of the 15 control subjects, had elevated urinary fluoride concentrations. The case patients had elevated serum fluoride concentrations and other abnormalities consistent with fluoride poisoning, such as elevated serum lactate dehydrogenase and aspartate aminotransferase concentrations. The fluoride concentration of a water sample from the implicated well was 150 mg per liter, and that of a sample from the other system was 1.1 mg per liter. Failure to monitor and respond appropriately to elevated fluoride concentrations, an unreliable control system, and a mechanism that allowed fluoride concentrate to enter the well led to this outbreak.

CONCLUSIONS:

Inspection of public water systems and monitoring of fluoride concentrations are needed to prevent outbreaks of fluoride poisoning.

By Gessner BD, Beller M, Middaugh JP, Whitford GM.|2019-05-27T02:35:31+00:00January 1st, 1994|Fluoride|

Evidence that mercury from silver dental fillings may be an etiological factor in smoking.

The smoking habits of 119 subjects without silver/mercury dental fillings were compared to 115 subjects with amalgams. The amalgam group had 2.5-times more smokers per group than the non-amalgam group, which was highly significant. Because mercury decreases dopamine, serotonin, norepinephrine, and acetylcholine in the brain, and nicotine has just the opposite effect on these neurotransmitters, this may help explain why persons with dental amalgams smoke more than persons without amalgams.

By Siblerud RL, Kienholz E, Motl J.|2020-04-02T20:07:55+00:00January 1st, 1993|Mercury|

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About Yamamoto T, Hirano K, Tsutsui H, Sugioka Y, Sueishi K.