Search

Objectives The question of health risks associated with dental materials, especially dental amalgam, has long been controversial and remains unresolved. For the past 10 years, people in Sweden with perceived adverse reactions to dental restorative materials have been entitled to apply to their local county council for subsidized replacement of restorative materials. The aim of the study was to investigate symptoms, perceived health changes over time and health-related quality of life ( HRQo L) in this population, comprising subjects with subjective health impairment, allegedly because of dental materials. A further aim was to compare their HRQo L with that of the general population. Methods A comprehensive questionnaire was sent to 515 people who had applied for subsidized replacement of dental restorations. The questionnaire covered general and oral symptoms, HRQo L, health ratings over time and dental restoration replacement. Results The response rate was 54.4% ( n = 280). Most (83.2%) answered that they had undergone replacement of restorative materials because of impaired health, perceived to be related to dental restorative materials. The most common symptoms were musculoskeletal pain (67.5%), sleep disturbance (60.0%) and fatigue (58.6%). The HRQo L of the study subjects was significantly lower than that of the Swedish population in general. Conclusions Subjects who had undergone subsidized dental restoration replacement reported persistent subjective symptoms and low HRQo L. The results indicate that replacement of restorative materials alone is insufficient to achieve improved health in patients with symptoms allegedly attributable to dental restorations. [ABSTRACT FROM AUTHOR]

The purpose of this study was to study the risk for injury and injury pattern in Swedish male elite football and to compare two different injury definitions. A prospective cohort study was conducted during 2001 on all 14 teams (310 players) in the Swedish top division. Injuries and individual exposure were recorded. Injury was defined as time-lost injury (715 injuries) and for comparison as tissue injury (765 injuries). No significant difference in the risk for injury between tissue injuries and time-lost injuries was found during matches (27.2 vs. 25.9 injuries per 1000 match hours,P=0.66) or training sessions (5.7 vs. 5.2 injuries per 1000 training hours,P=0.65). The risk for injury during training was significantly higher during the pre-season compared with the competitive season (P=0.01).Thigh strain was the single most common injury (14%). Knee sprain was the most common major injury (absence>4 weeks). Overuse injuries and re-injuries were frequent and constituted 37% and 22% of all injuries. Re-injuries caused significantly longer absence than their corresponding initial injuries (P=0.02). The risk for re-injury (P=0.02) and overuse injury (P<0.01) was significantly higher during the pre-season compared with the competitive season. [ABSTRACT FROM AUTHOR]

The Danish and Swedish male top football divisions were studied prospectively from January to June 2001. Exposure to football and injury incidence, severity and distribution were compared between the countries.Swedish players had greater exposure to training (171 vs. 123 h per season,P<0.001), whereas exposure to matches did not differ between the countries. There was a higher risk for injury during training in Denmark than in Sweden (11.8 vs. 6.0 per 1000 h,P<0.01), whereas for match play there was no difference (28.2 vs. 26.2 per 1000 h). The risk for incurring a major injury (absence from football more than 4 weeks) was greater in Denmark (1.8 vs. 0.7 per 1000 h,P=0.002). The distribution of injuries according to type and location was similar in both countries. Of all injuries in Denmark and Sweden, overuse injury accounted for 39% and 38% (NS), and re-injury for 30% and 24% (P=0.032), respectively.The greater training exposure and the long pre-season period in Sweden may explain some of the reported differences. [ABSTRACT FROM AUTHOR]

The Swedish male senior national football team was followed prospectively between 1991 and 1997. During these 6 years, the team played 73 official matches and had three training camps. The senior author (J. E.) attended 57 of these matches and the three training camps and these matches and training camps, are included in the present study. Exposure to football was recorded individually for each player. The team physician examined all injuries. Total exposure was 7245 h (6235 training and 1010 match hours) and there were 71 injuries (40 training and 31 match injuries). Five (16%) of the match injuries were major, with more than 4 weeks of absence from football. The injury incidence during training was 6.5/1000 h and the injury risk during matchplay was 30.3/1000 h. A significantly higher injury incidence was found for matches lost compared to matches won or drawn (52.5 vs. 22.7/1000 h, P=0.026). No statistically significant difference for injury was found between competitive matches and friendly matches. No difference was found between home and away matches or matches on neutral ground. The risk for injury when playing in a national team compares with previously reported figures for professional football at a high level. [ABSTRACT FROM AUTHOR]

The long-term development of injury risk in Swedish male elite football was studied. Two prospective cohort studies from seasons 1982 and 2001 were compared with respect to exposure to football, injury incidence and injury severity. The mean number of training sessions during the season had increased by 68% between 1982 and 2001 (142 vs. 238, P<0.001), whereas teams played more matches in 1982 (49 vs. 41, P=0.02). The total exposure to football had increased by 27%. Three out of four players incurred an injury in both seasons. In 2001, players suffered more training injuries due to an increased training exposure. Accounting for risk exposure, there was no difference in injury incidence or severity between the two seasons. The incidence was 8.3 injuries/ 1000 h of total exposure (4.6 in training and 20.6 in matches) in 1982, compared to 7.8 1000 h−1 (5.2 in training and 25.9 in matches) in 2001. Major injuries accounted for 9% of all injuries, corresponding to an incidence of 0.8 /1000 h of football, in both seasons. A trend from semi-professionalism to full professionalism in Swedish elite football was seen during the last two decades. The injury risk did not change over the same period. [ABSTRACT FROM AUTHOR]

The current study was undertaken to analyse growth and differentiation-related functions of normal keratinocytes (NOK) and an SV40T-immortalized keratinocyte line (SVpgC2a) from buccal mucosa, viewing the latter cell line as a model of a dysplastic epithelium. Morphological and immunohistochemical assessments of organotypic epithelia generated from 10 or 17 d of culture showed three- to five-fold higher apoptotic and proliferative activity in SVpgC2a relative to NOK. Conditions with or without serum (up to 10%) did not significantly influence these parameters in NOK whereas serum supported proliferation of SVpgC2a. Both cell types showed basal expression of collagen IV and laminin 1, indicating basal lamina, as well as vimentin, indicating an activated, proliferative state. Reduced expression of keratin, including the non-keratinizing marker K13. was seen in SVpgC2a. Assessment of proliferative monolayer cultures by microarray showed that NOK transcribed tissue-specific keratins, but also the epidermal keratin K2a, several simple epithelial keratins and low levels of hair keratins. SVpgC2a transcribed keratins seen in epithelial dysplasia, and K2a and hair keratins, albeit at low level. Overall, the results implied aberrant apoptosis, proliferation and keratin expression in the immortalized state of SVpgC2a. Comparison of NOK and SVpgC2a under identical culture conditions may serve to model the progression from a normal to a pre-neoplastic state of buccal epithelium. [ABSTRACT FROM AUTHOR]

Fluoride was added in increments to pooled whole saliva. The ionized calcium concentration was determined in the saliva and the salivary sediment after centrifugation. The maxima of the ion product with respect to calcium fluoride were for salivary sediment and saliva found at 15 mmol/1 and 25 mmol/1 of fluoride, respectively. The study indicated that calcium fluoride may precipitate in the plaque matrix during and after topical application of fluoride. [ABSTRACT FROM AUTHOR]

The effect of fluoride ingestion on plasma and urinary cyclic AMP levels was studied in healthy volunteers, children undergoing prophylactic fluoride treatment and in rats. In the first series of experiments fluoride ingestion led to a 20-fold increase in plasma fluoride concentration, which was unrelated to changes in plasma cyclic AMP. The only significant effect on plasma cyclic AMP occurred prior to fluoride, an effect attributed to stress. In the second series performed in children increases in urinary F- of up to 200-fold were associated with slight but nonsignificant changes in cyclic AMP excretion. In rat experiments the blood sampling procedure was associated with a rise in plasma cyclic AMP. When this was prevented by pretreatment with propranolol (3 mg/kg), the effect of fluoride (50 ppm in the drinking water) was tested. A fall in urine production was not associated with any change in cyclic AMP excretion or in nephrogenic cyclic AMP. It is concluded that if fluoride alters cyclic AMP in rats and man the effect is small and easily masked by other factors such as catecholamine release following stress. [ABSTRACT FROM AUTHOR]

In a double blind cross-over study, 20 subjects were given either a sugar free chewing gum containing 0.25 mg fluoride or the same chewing gum without fluoride, eight times a day for 7 days. The pH of 3-day-old plaque was determined before and after each experimental period following a 30-s mouth-rinse with 10 ml 15% sucrose. The pH-decrease was significantly less pronounced after using the fluoride gum than after the placebo gum (P<0.001). In a second study, 20 subjects participated in a similar study. In this experiment the acid production activity from sucrose in dental plaque in vitro was determined with the aid of a titration method. In addition, the dental plaque wet weight and the total number of cultivable organisms, Streptococcus mutans and lactobacilli, expressed as the number of colonies per mg plaque, were determined. No significant effect was found on any of these parameters after using the fluoride gum compared to the placebo gum. Thus, the results indicate that slightly elevated levels of fluoride in saliva during daytime, achieved by repeated intake of fluoride gums for 7 days, are sufficient to influence the acidogenicity of dental plaque in vivo. [ABSTRACT FROM AUTHOR]

This paper summarizes some recent reports on mercury release from amalgam fillings and resulting concentrations in biological fluids, development of antibiotic resistance, and kidney function. In a series of studies of subjects with amalgam fillings, mercury (Hg)levels were followed in saliva, feces, blood, plasma, and urine before and until 60 d after removal of all of the fillings. The Hg concentrations in saliva remained elevated for at least 1 wk, suggesting that dissolved Hg vapor is not the major source of mercury in mixed saliva. An absorption phase of Hg was seen in plasma during 24 h after amalgam removal. After 60 d the plasma Hg concentration was reduced to 40% of the baseline level. The decrease per amalgam surface was 0.11 nmol/l(range 0.02-0.40). The Hg level in feces increased two orders of magnitude two days after amalgam removal. At day 60, the median Hg concentration was still slightly higher than the median value of the amalgam free control group. The resistance patterns of the oral and intestinal microflora in these subjects were also studied. In the intestinal microflora, the relative amount of intestinal microorganisms resistant to 50 μM HgCl[sub2] peaked 7 d after removal of the amalgam fillings, with a median value per sample of 6.1% compared to 1.3% in samples collected prior to the Hg exposure. However, no statistical differences in the resistance pattern of the oral microflora were detected between the control and the experimental groups. A number of sensitive kidney function parameters were measured 1 wk before and 1,2 and 60 d after amalgam removal. No effects on the various kidney parameters studied were recorded. According to the conclusions of independent evaluations from different state... [ABSTRACT FROM AUTHOR]

A micro-analytic method, capable of measuring the fluoride concentration in 5 nl of plaque fluid, was used to follow changes in fluoride concentration in saliva and plaque fluid at 6 single tooth-sites in 6 subjects for 180 mm after a 0.048 M fluoride rinse as a NaF or MEP (sodium monofluorophosphate) solution. The maximum fluoride concentrations in saliva after NaF was 13 × higher than with MFP. About 5% of the total amount of fluoride following the 20 ml NaF rinse was retained in the oral cavity. The corresponding figure following MFP was <1%. The saliva/plaque fluid fluoride ratios for upper molars and lower incisors were significantly higher than for the upper incisors and lower molars. There was a tendency for a decline in the ratios with respect to time for all sites. To characterize the plaque fluid fluoride intra-oral single- site distribution and clearance, fluoride concentration versus time (AUC) was calculated from 10 to 60 min after a rinse. The NaF AUC followed the order: upper incisor, lower molar, upper molar and lower incisors reflecting a different exposure and clearance pattern due to the different access of the plaque to saliva. The MFP AUC values varied more, but were all significantly lower than the NaF AUC values. Analysis of plaque fluid fluoride curves at various sites revealed an exponential decline in most cases. With NaF, the baseline plaque fluid fluoride levels were not reached within 3 h. It is concluded that NaF solutions result' in a significantly higher intra-oral fluoride exposure than MFP solutions. The fluoride distribution and clearance of fluoride from different sites in the oral cavity are linked to salivary access to these sites. These site-specific differences may have clinical consequences with regard to the dynamics of fluoride in the de- and remineralization processes. [ABSTRACT FROM AUTHOR]

The dissolution rate of CaF2 tablets in vitro and the degree of F absorption in vivo after tablet intake in man were investigated. 50% of total F was released in 0.1 N HCl after 45 min whereas virtually no release was seen in H2O or in 0.2 M PO4-buffer pH 6.8. In spite of the modest release of F in simulated gastric juice in vitro no F absorption as judged from the plasma fluoride concentration curve was seen within 6 h after intake of 4 mg F as CaF2 tablets. [ABSTRACT FROM AUTHOR]

The saliva and plasma fluoride (F) concentrations following intake of different doses of fluoride tablets were studied in six subjects. There was a close relationship between saliva F and plasma F and the ratio was 0.64±0.01 (s.e.). The plasma half life of F was 4-16 h. This results indicate that saliva F may be a useful substitute for blood sampling in studies concerning the pharmacokinetics of fluoride. [ABSTRACT FROM AUTHOR]