Mercury concentrations in blood from Danish dentists

Blood samples from a group of 130 dentists and a control group of 40 blood-donors were analyzed by cold vapor atomic absorption spectrophotometry in order to evaluate the extent of mercury exposure. The median blood concentration of mercury was 4.0 (range: 1.2-19.2) micrograms/l for dentists and 2.0 (1.1-4.6) micrograms/l for controls (2P less than 0.01). Practice characteristics obtained in a questionnaire showed no statistically significant relationship to blood mercury, but 49 dentists having one or more fish meals per wk, had a median concentration of mercury, which was 47% higher than dentists seldomly consuming fish (2P less than 0.01). It was concluded that none of the examined dentists had blood concentrations above the level (35 micrograms Hg/l) associated with the hygienic threshold limit.     

Mercury levels in urine and head hair of dental personnel

As dentists and their assistants are usually exposed to mercury in their clinical practices. The objective was to investigate the mercury level in these dental personnel. Urine and head hair samples were collected from 201 dental personnel and 57 unexposed controls for mercury analysis. The mercury content was analyzed by using cold vapour atomic absorption spectrophotometry. The results showed that mercury levels in the urine and head hair of dental personnel were significantly higher than in the controls (P less than 0.01). The urine mercury concentration of the unexposed controls ranged from 0.1-10.0 micrograms/l (means = 2.6 +/- 0.29 micrograms/l). The highest urine mercury level was found in the group of dental assistant (means = 17.1 +/- 2.44 micrograms/l). The mean urine mercury levels found in dentists, dental students and dental technicians were 10.1 +/- 1.42, 11.1 +/- 1.69 and 3.2 +/- 0.69 micrograms/l respectively. The amounts of urine mercury from dental assistants, dentists and dental students were 81.0%, 38.2% and 43.5% higher than the threshold limit value respectively. The mean head hair mercury concentration of unexposed controls ranged from 0.3-12.2 micrograms/g (means = 2.8 +/- 0.36 micrograms/g). The highest head hair mercury concentration was found in the group of dental assistant and 6th year dental students (means = 10.1 +/- 0.84 and 10.5 +/- 3.2 micrograms/g). The mean head hair mercury levels found in dental assistants, dentists, dental students and dental technicians were 10.1 +/- 0.84, 7.5 +/- 1.2, 6.5 +/- 1.54 and 2.8 +/- 0.53 micrograms/g respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparative study on mineralization-related intraoral parameters in periodontitis-affected and periodontitis-free adults

Abstract – The parameters related to an intraoral mineralization tendency in periodontitis-affected (P+) and periodontitis-free (P-) study subjects (16 adults, 46–74 yr, matched for sex and age) were compared. For this purpose the calcium (Ca) and phosphate (P) concentration of both plaque and saliva, resting pH and the acidogenic response of interdental plaque, plaque wet weight, salivary flow rate, buffering capacity and sucrase activity, interdental and salivary S. mutans levels as well as salivary lactobacilli and yeast levels were estimated. Plaque Ca (μg/mg protein, P <0.025) and P (μg/mg protein, P <0.05), saliva Ca (μg/ml, P <0.005) and the saliva Ca:P ratio ( P <0.005) were higher in the P+ than in the P- group. The resting pH values were higher ( P <0.025) and the acidogenic response of the interdental plaque was lower ( P <0.025) in the P+ group than in the P- group. The P+ group had lower S. mutans levels in saliva and interdental plaque. No differences were found in the wet weight of plaque and in the flow rate, buffering capacity or sucrase activity of saliva between the groups. The findings of the mineralization-related parameters in the two "extreme" groups of periodontal status suggest a higher intraoral mineralization tendency in periodontitis-affected persons than in periodontitis-free subjects. Ca and P accumulation of supragingival plaque seem to be connected with low acidogenicity of plaque and high salivary Ca concentration.     

Antimony, arsenic, bromine and mercury in enamel from human teeth

ABSTRACT – The concentrations of antimony, arsenic, bromine, and mercury have been determined in enamel from ancient and contemporary human teeth. Fifty-two enamel samples were analyzed: 10 from 2300–1500 B.C., 8 from 400 B.C. - 200 A. D., 3 from 800–1100 A. D., 14 from 1100–1400 A. D., 5 from the 1850's, and 12 from the present time. All teeth were taken from dated skulls or young patients with no fillings. The samples weighed between 30 mg and 60 mg. The concentrations of the four elements were determined after neutron activation and radiochemical separation by means of a Nal(TI) scintillation well detector and a T. M. C. 400-channel analyzer. The ranges of concentrations were antimony: < 0.001–1.59 μg per g enamel; arsenic: < 0.001–0.406 μg per g; bromine: 0.87–7.3 μg per g; mercury: 相似文献   

Patients complaining about amalgam-related symptoms suffer more often from illnesses and chronic craniofacial pain than their controls

Abstract – All patients who during the academic year 1987–88 had come or were referred for investigation to the Institute of Dentistry, University of Oulu, because of their anticipated amalgam-related symptoms were included in the study. The group comprised 20 patients, 7 men and 13 women, 41.6 ± 11.1 yr old. For paired controls, 20 age and sex matched subjects were randomly selected among other patients at the Institute. The subjects' medical and dental history was taken, they were all examined clinically, and saliva analyses were done. The subjects were tested with standard patch test series of 25 common dental allergens. All patients were given the possibility to give a blood test for mercury concentration analysis, but only five were willing to do so. The results showed that the group of 20 patients suffered significantly more often from medical illnesses than the controls ( P <0.05). Chronic craniofacial pain was diagnosed significantly more often among the patients than in the controls ( P <0.01). The controls had more caries than the patients, but there was no difference in any other clinical, salivary chemical or microbiological findings between the groups. In the five patients who gave blood samples, both inorganic and organic mercury levels were below threshold values. No difference was observed between the patients and controls in the allergy test reactions.     

Factors affecting blood mercury concentrations in practicing dentists.

It has been suggested that mercury vapor may be transformed into highly toxic organomercury compounds by micro-organisms in the oral cavity and gastrointestinal tract. If this hypothesis is correct, practicing dentists might be expected to have concentrations of organic mercury in their blood higher than that found in non-dentists. Blood mercury concentrations of practicing dentists and non-dentists were determined by means of cold-vapor atomic absorption spectrophotometry. Potential sources of mercury exposure were identified in both dentists and non-dentists through a questionnaire completed at the time of sampling. Concentrations of total and inorganic blood mercury were significantly higher in dentists than in non-dentists. The organomercury concentrations of the two groups were not statistically different (p greater than or equal to 0.05). The high concentration of inorganic mercury in the blood of dentists was not related to the organomercury level, suggesting that biotransformation of inorganic mercury to organomercury does not occur in vivo. However, the concentration of blood organomercury was positively correlated with the frequency of fish consumption. There was no correlation between the number of amalgam restorations and the concentration of inorganic blood mercury for both groups. Accidental mercury spills in the dental operatory may contribute most to the concentration of inorganic blood mercury in the blood of dentists.     

On the mechanism of cytotoxicity of silver and copper amalgams in a cell culture system

ABSTRACT – Silver and copper amalgams show a pronounced cytotoxic effect on monolayer cultures of human epithelial cells (NCTG 2544). Analyses of the medium from silver amalgam cultures showed that, zinc was released in substantial amounts (14 μg/ml after incubation for 24 h). Small amounts of mercury and possibly also some silver were released, whereas release of copper and tin could not be. detected. Toxicity tests showed that 10 μg Zn²+/ml reduced the number of cells by 96% after incubation for 24 h. In the copper amalgam cultures about. 100 μ g copper and 5 μg, cadmium per ml medium were found after 24 h. Only small amounts of mercury were released, Toxicity tests showed an increasing effect of Cu²+ and Cd²+ with tune. With 50 μg Cu²+/ml the number of cells was reduced by 73% after incubation for 24 h, and after 3 d a similar effect was found with 25 μg/ml. With 10 μg Cd²+/ml no cells were left after 24 h, whereas after 3 d 1μg/ml reduced cell growth by more than 80 %.     

A study of the elimination of chlorhexidine from tthe oral cavity using a new spactrophotometric method

A method for the determination of chlorhexidine in saliva is described. The mean recovery rates observed with chlorhexidine digluconate added to saliva in the ranges 5–25,μg/ml and 25–200 μg/ml where 103.6 % and 102.8 % respectively. The lower limit of the method is in the vicinity of 5 μg of chlorhexidine digluconate. The accuracy was found to be ± 3 % and ± 1 % when the concentration of the samples were in the ranges 5–25 μg/ml and 25–200 μg/ml respectively. The method is not specific for chlorhexidine and the amount of interfering material in saliva was found to be equivalent to 3.45 ± 0.54 μg/ml of chlorhexidine digluconate. The rate of elimination of chlorhexidine digluconate from the mouth after one mouthrinse with 20 mg followed approximately the equation describing a process of the first order. The mean values of the half-times (t/2) and the initial concentrations (C_max) was found to be 63 ± 11 min and 153 + 27 μg/ml respectively. The concentration of chlorhexidine digluconate was higher than the proposed minimal inhibitory concentration for oral streptococci of 5 μg/ml for approximately 5 hours. The significance of this in relation to the clinical effect of mouthrinsing with chlorhexidine is discussed. The amount of chlorhexidine digluconate swallowed after one mouthrinse was estimated to be approximately 4 mg corresponding to 20 % of the dose.     

Effects of the anti-androgen finasteride on 5α-reductase activity in human gingival fibroblasts in response to minocycline

Abstract. In addition to their antimicrobial properties, tetracyclines have anti-inflammatory and pro-anabolic effects on the reparatory potential of connective tissue and bone. The physiologically active androgen 5α-dihydrotestosterone(DHT) implicated in matrix synthesis is formed in gingivae from androgen substrates. The aim of this investigation is to study the androgen metabolic response of gingivae to minocycline, in the presence or absence of the anti-androgen finasteride. Chronically inflamed gingival tissue derived from 12 subjects aged 30–50years and passaged fibroblasts derived from this source, were used for the experiments. Duplicate incubations were performed in Eagle's MEM with 14C-testosierone/14C-4-androstenedione in the presence or absence of minocycline (5–60 μg/ml) or finasteride for 24 h. The androgen substrate 14C-testosteronewas metabolised mainly to DHT and 4-androstenedione, while 14C-4-andros-tenedione was converted mainly to DHT and testosterone. Minocycline at 20–30 μg/ml stimulated the formation of these metabolites from both substrates by 13–25%. In the tissue incubations there were 3- and 2-fold increases in DHT and 4-androstenedione formation (n=12; p <0.01). The anti-androgen finasteride caused significant inhibition of 5α-reductase activity on both substrates at 0.1 & 1.0 μg/ml with total inhibition at 10 & 50 μg/ml (n=3; p <0.01). Minocycline-induced stimulation of 5α-reductase activity was also inhibited by finasteride (n=4; p <0.02). Since finastcride inhibition of 5α-reductase activity is specific for the type 2 isoenzyme associated with anabolic functions of target tissue, this enzyme activity may contribute to some of the cited anabolic tissue responses to minocycline.     

Cell generation within the interdental gingival septum of the rat

The aims of this investigation were to determine whether connective tissue progenitor cells in the interdental gingival septum (IGS) have a paravascular origin, and how the distribution of ³HTdR-labelled cells within the IGS changes with time after a single injection. 30 male hooded Lister rats aged 6 weeks, were killed in groups of ten, 3, 75 and 171 h after a single injection of tritiated thymidine. Autoradiographs were examined of 3 transverse Historesin sections of the papilla between second and third mandibular molars in 29 specimens, taken at equidistant intervals between the col and alveolar bone crest. At all times and levels, 73.9–93.0% of labelled cells and 72.0–79.0% of unlabelled cells lay within 50 μm of blood vessels (BVs). The highest percentages of labelled cells (PLCs) occurred within 5 μm of BVs (P < 0.001) although mean nuclear density here was lowest (P < 0.017), and there was a significant diminution of PLC (P < 0.05) with increasing distance from BVs, occurring most precipitously 5–10 μ from vessel walls. Sites of significantly increased PLC at 3 h also approximated to sites in which mean BV densities were greatest. At 3 h, a number of discrete sites with significantly increased PLCs (P < 0.05) were found within two zones, each equivalent to 40% of IGS volume and juxtaposed with each tooth. At later times, additional sites of raised PLC appeared throughout the IGS. Overall PLCs in the upper two levels and within 5 μm of BVs also increased over the timecourse (P < 0.01). These data are consistent with the existence of paravascular connective tissue progenitor cells within the outer zones of the IGS closest to the teeth. Labelled cell distributions at 75 h and 171 h did not provide firm evidence of translocation within the IGS.     

Dentin formation in formocresol pulpotomized primary monkey teeth studied by tetracycline and 3H-proline incorporation

Abstract – The influence of formocresol treatment on the pulp tissue of 24 primary monkey teeth was studied using tetracycline and ³H-proline labeling techniques. Six untreated monkey teeth served as controls. The tetracycline labeled teeth were examined between 352 and 600 d, following treatment. The ³H-proline labeled teeth were observed over a period of 22–607 d, the isotope being administered 15 d before extraction. The labeling was evaluated in the coronal, middle and apical area of the roots. Dentin formation as indicated by tetracycline labeling was observed in both control teeth and successfully treated teeth, as well as in some of the unsuccessfully treated teeth. The average dentin formation rate per day varied from 1 μm in the control teeth to 0.14 μm in the pulpotomized teeth ( P <0.01). Success of treatment was of significant importance for the amount of dentin formation ( P <0.001). Labeling with ³H-proline, indicating collagen synthesis, could be observed in the pulp and predentin of the majority of areas judged to be normal, degenerated or inflamed. Labeling was not observed in fixed or necrotic tissue. In degenerated pulp tissue the proline labeling was clearly reduced. The findings indicate that dentin formation and collagen synthesis may take place in formaldehyde influenced pulp tissue although at a decreased rate.     

Effects of areca nut, inflorescence piper betle extracts and arecoline on cytotoxicity, total and unscheduled DNA synthesis in cultured gingival keratinocytes

Betel quid (BQ) chewing has a strong correlation with oral leukoplakia, submucous fibrosis and oral cancer. For elucidation of its pathogenesis, we investigated the effects of areca nut (AN) and inflorescence piper betle (IPB) extracts and arecoline on the growth, total DNA synthesis (TDS) and unscheduled DNA synthesis (UDS) of cultured human gingival keratinocytes (GK). Arecoline and AN extract suppressed the growth of GK over 5 days of incubation in a dose-dependent fashion. At concentrations of 100, 200 and 400 μg/ml, AN extract suppressed the growth of GK by 31%, 46% and 90%, respectively. The IPB extracts exerted less inhibitory effect on the growth of GK. IPB extract (200–400 μg/ml) decreased cell numbers by 20–40% over 5 days of incubation. Moreover, at a concentration of 0.1, 0.2 and 0.4 mM, arecoline suppressed cell growth by 44%, 77% and 96%, respectively. However, only AN extract induced TDS and UDS in cultured GK within 6 h of exposure. Induction of UDS by AN extract was concomitant with the presence of apparent intracellular vaculoization. Arecoline was also toxic to GK, but did not induce intracellular vacuolization. At a concentration range of 200–1600 μ/ml, AN extract induced TDS by 2.1- to 6.5-fold. Furthermore, at a concentration of 400–1600 μ/ml, AN extract elevated the UDS by 2.4- to 5.5-fold more than that of untreated control. On the contrary, IPB extract (200–1600 μ/ml) and arecoline (0.2–1.6 mM) inhibited the TDS and UDS of GK to a different extent. Simultaneous exposure of confluent GK to AN extract, IPB extract and arecoline for 1 to 5 days led to different degrees of cytotoxicity that was dose-and time-dependent. These results indicate that AN, IPB and arecoline take part in the pathogenesis of BQ chewing-related oral mucosal lesions, possibly through both genotoxic and non-genotoxic mechanisms.     

β-lactamase-producing strains in the species Prevotella intermedia and Prevotella nigrescens

A total of 96 strains were collected that included laboratory strains and clinical isolates classified Prevotella intermedia sensu lato and the type strains of the species P. intermedia sensu stricto and Prevotella nigrescens. Susceptibility to amoxicillin and amoxicillin-clavulanic acid was determined by the Etest. PCRDNA probe assays were used to speciate each strain as P. intermedia sensu stricto or P. nigrescens. By Etest, 71 strains (74%) were susceptible to both amoxicillin and amoxicillin-clavulanic acid with minimum inhibitory concentrations in the 0.016–0.064 μg/ml range. In contrast, amoxicillin minimum inhibitory concentrations of 25 strains (26%) were in the range of 1.5–96 μg/ml with concomitant amoxicillin-clavulanic acid minimum inhibitory concentrations in the low range 0.016–0.38 μg/ml, indicating a production of β-lactamase as confirmed by nitrocefin tests. Of these β-lactamase-producing strains, 20% (5/25) were identified as P. intermedia sensu stricto by the PCR-DNA probe assay and 72% (18/25) as P. nigrescens. Our results provide support for the major role of P. nigrescens in the failure of therapy using β-lactam antibiotics.     

Nicotine effects on PGE2 and IL-1β release by LPS-treated human monocytes

Cigarette smoking is a major risk factor in the development and further progression of periodontitis. However, little is known regarding the pathogenesis of smoking-related periodontal diseases. The purpose of this study was to examine the effects of nicotine, alone and in combination with lipopolysaccharide (LPS), on monocyte secretion of bone-resorbing factors, PGE₂ and IL-1β. Peripheral blood monocytes (PBM) were isolated by counterflow centrifugal elutriation from 15 healthy, non-smoking donors. PBM were incubated for 24 h in RPMI 1640 containing nicotine (0, 50 μg/ml, I μg/ml, 10 μg/ml and 100 μg/ml) with or without 10 μg/ml Porphyromonas gingivalis LPS or Escherichia coli LPS. Culture supernatants were assayed for PGE₂ and IL-1β by ELISA. None of the nicotine preparations resulted in significant PBM secretion of PGE₂ and IL-1β above that of unstimulated cultures. However, PGE₂ release was potentiated 1.7-fold by the combination of P. gingivalis LPS and 10 μg/ml nicotine relative to P. gingivalis LPS alone (p<0.05, one-way ANOVA). Prostaglandin E₃ release also was potentiated 3.5-fold by P. gingivalis LPS and 100 μg/ml nicotine relative to P. gingivalis LPS alone (p<0.00001, one-way ANOVA) and 3.1-fold by E. coli LPS and 100 μg/ml nicotine relative to E. coli LPS alone (p<0.00001, I. one-way ANOVA). IL-1β secretion was lower for either LPS plus 100 μg/ml nicotine relative to LPS alone, although not significantly. These data demonstrate upregulation of LPS-mediated monocyte secretion of PGE₂ by nicotine and suggest a potential role for nicotine in periodontal disease pathogenesis.     

Influence of borneol on primary mice oral fibroblasts: a penetration enhancer may be used in oral submucous fibrosis

Background:  Borneol, a widely used food and cosmetics additive, has analgesic, anti-inflammatory, antibacterial and penetration enhancing effects. We try to use it as a penetration enhancer for a formula which we have used to treat oral submucous fibrosis (OSF). To assess its safety, we investigate its effects on primary mice oral fibroblasts.
Methods:  Primary mice oral fibroblasts were cultured, the effects of borneol on fibroblasts proliferation, cytotoxicity, collagen production, matrix metalloproteinases-2,9 (MMP-2,9) activities and tissue inhibitors of metalloproteinase 1 (TIMP-1) production were tested by methyl thiazolyl tetrazolium assay, lactic dehydrogenase activity assay, chloramine T method, gelatin zymography and enzyme-linked immunosorbent assay, respectively.
Results:  Borneol, from 18.75 to 300 μg/ml, could significantly ( P  < 0.05) decrease the growth of fibroblasts and very significantly ( P  < 0.01) inhibit collagen production in a concentration dependant manner. From 18.75 to 150 μg/ml, borneol had no cytotoxicity on mice oral fibroblasts. Moreover borneol could significantly ( P  < 0.05) decrease MMP-2 activity, and very significantly ( P  < 0.01) inhibit TIMP-1 production.
Conclusions:  This study indicates that borneol has anti-fibrosis activity and the mechanism may partly be relevant to its inhibiting effects on fibroblasts mitosis, collagen and TIMP-1 production. It can be safely used as a penetration enhancer for our formula to treat OSF.     

The relationship between amalgam restorations and mercury levels in male dentists and nondental health professionals

OBJECTIVES: The objectives of this study were: (1) to compare the mercury levels in general dentists with the mercury levels in other health professionals using toenail clippings as a biomarker, (2) to identify risk factors associated with high mercury levels, and (3) to compare practice characteristics of dentists with high and low mercury levels. METHODS: A sample of 579 men was randomly selected from the 33,737 men participating in the Health Professionals Follow-up Study who had provided toenail samples in 1987. A questionnaire was sent to these male subjects in 1991 to obtain information on fish consumption, toothbrushing frequency, number of teeth, number of amalgam restorations, general practice or specialty status, number of amalgam restorations placed and removed per week, mercury storage and handling procedures, and mercury spillage incidents. A measure of long-term mercury exposure was obtained from toenail samples using neutron activation analysis for the 410 respondents (71% response rate). The 90th percentile mercury level in toenails (0.88 ppm) was selected as the threshold for elevated toenail mercury level. RESULTS: No relationship was found between the number of dental amalgams and toenail mercury levels among general dentists, dental specialists, and nondental health professionals. General dentists were found to have more than twice the level of mercury in toenails than nondental health professionals (mean level = 0.94 vs 0.45) and 60 percent higher than dental specialists (mean = 0.59). The combined use of disposable capsules and water storage of scrap amalgam appeared to reduce the risk of elevated mercury levels. Regardless of professional status, consumption of tuna and saltwater fish were the primary exposure factors that were positively associated with toenail mercury levels. CONCLUSIONS: As shown by the associations with dental profession and fish consumption, the mercury content of toenails is a stable biomarker of cumulative long-term mercury exposure. The lack of association between nail mercury levels and number of amalgam restorations suggests that avoidance of mercury amalgam restorative materials cannot be justified by the presence of mercury released from dental amalgams.     

The in-vitro sensitivity of oral spirochaetes to metronidazole

Ten pure strains of oral spirochaetes, having the same morphological and cultural characteristics as Treponema denticola, were isolated from 8 patients with acute necrotizing ulcerative gingivitis (ANUG). Penicillin and Metronidazole were tested for their ability to inhibit growth of these ten strains in vitro. The visual end point was 0.0–0.001 μ/ml for Penicillin and 0.1–0.01 μg/ml for Metronidazole. The significance of these results is discussed in relation to the aetiology and management of ANUG.     

Effect of a moderate vitamin A deficiency on saliva secretion rate and some salivary glycoproteins in adult rat

Abstract – The study presents the effect of a low vitamin A intake on saliva secretion rate and some salivary glycoproteins in the adult rat. Sixteen rats in the experimental group were fed a vitamin A deficient diet (0.11 μg retinol/g diet) and 14 rats in the control group a diet with adequate content of vitamin A (4.74 μg/g diet). At the end of the experimental period of 10 wk, whole saliva, blood, and liver samples were collected. No difference in the serum content of retinol was seen between the two groups. The liver values were significantly lower for the rats in the experimental group compared to the values in the control group. No difference was seen between the two groups in saliva secretion rate, salivary peroxidase activity, or the concentrations of total protein and markers for total glycoprotein secretion. However, the activity of a bacteria agglutinating glycoprotein, BAGP, was significantly reduced in the rats fed the vitamin A deficient diet.     

An in vivo Study of the chlorhexidine release profile of the PerioChipTM in the gingival crevicular fluid, plasma and urine

Abstract. The release profile of chlorhexidine from the PerioChip^TM (Chip), a biodegradable local delivery system that contains 2.5 mg of chlorhexidine gluconate (CHX) in a cross-linked hydrolyzed gelatin matrix, into the gingival crevice, was evaluated in an in vivo, open label, single-center. 10-day pharmacokinetic study conducted on 19 volunteers with chronic adult periodontitis. Each volunteer had a single chip inserted into each of 4 selected pockets, with probing pocket depths of between 5–8 mm. at time 0. Gingival crevicular fluid (GCF) samples were collected using filter paper strips prior to Chip placement and at 2 h, 4 h, 24 h and 2, 3, 4, 5, 6, 8, and 9 days post-Chip placement. The GCF volume was measured using a calibrated Periotron^TM 6000. Blood samples were collected at times 0, 1, 4, 8, 12 h and 5 days post-dosing. Urine was collected as a total 24-h specimen immediately post-dosing and 2 single samples at time 0, prior to dosing, and 5 days. The CHX was eluted from the paper strips and the CHX levels in GCF. blood and urine quantified using HPLC. The results indicate an initial peak concentration of CHX in the GCF at 2 h post-Chip insertion (2007 μ/ml) with slightly lower concentrations of between 1300–1900 μg/ml being maintained over the next 96 h. The CHX concentration then progressively decreased until study conclusion with significant CHX concentrations (mean=57 μg/ml) still being detectable at study termination. CHX was not detectable in any of the plasma or urine samples at any time point during the study. These results indicate that the PerioChip^TM can maintain clinically effective levels of CHX in the GCF of periodontal pockets for over 1 week with no detectable systemic absorption.     

Clinical study of oral galvanism: no evidence of toxic mercury exposure but anxiety disorder an important background factor

A total of 142 women and 76 men with self-diagnosed oral galvanism who were referred from dentists and medical doctors for clinical evaluation during the last 2 yr are described from the perspective of general medicine. No case of clinically suspected mercury intoxication was found. Mean concentration of mercury in whole blood (B-Hg) was 17.3 nmol/1, and no value exceeded 50 nmol/1. Amalgam burden and B-Hg were not associated with clinical signs or symptoms except for a significantly lower mean value of B-Hg in patients with psychologic main symptoms than in those without (mean 15.4 vs. 18.1 nmol/1). It was possible to make one or several diagnoses in all 218 cases as reasonable alternatives to the concept of oral galvanism. Mental disorder was the main diagnosis in 93 cases (42.7%), including 41 cases of generalized anxiety disorder and 12 cases of panic disorder. A total of 87 patients (40%) did not work because of medical reasons or unemployment. Amalgam removal was recommended in a total of 65 cases (29%), mainly on psychologic indications, but in 22 cases because of oral conditions. The clinical conditions behind the concept of oral galvanism seem to be explicable in terms of general medicine, and no generalized toxic effect of amalgam fillings need be suspected.