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Biomedical subjects

L Frithiof

Publications and source records attributed to L Frithiof.

At least 19 recordsLinked to original sources
PubMed2001

Relationship between oral health and mortality in cardiovascular diseases.

BACKGROUND, AIMS: The purpose of the study was to investigate the relationship between periodontal health and fatal cardiovascular diseases (CVD). METHODS: The investigation was conducted on a sample of 1393 individuals in the County of Stockholm. The subjects were examined in an epidemiological study in 1970 with respect to dental health. At a follow-up in 1997, the mortality rate of the sample during the years 1970-1996 was registered as well as cause of death according to the death certificate. Stepwise logistic regression analysis was performed in order to evaluate the influence of the investigated variables on the incidence of death from CVD. RESULTS: The interactional effect between plaque and oral health score (a sum of scores for number of missing teeth, apical lesions, caries lesions and marginal bone loss), adjusted for age, gender, smoking and CVD at baseline, was significantly correlated to fatal coronary events. For individuals younger than 45 years of age, the age-adjusted incidence odds ratio of death due to CVD was 2.7 (p=0.04) if subjects with mean marginal bone loss of >10% were compared with subjects with mean marginal bone loss < or =10 %. If the stratum of individuals <45 years of age is confined to smokers, the odds ratio was found to be 3.4 (p=0.03). CONCLUSION: Dental health was found to be a risk indicator of death due to CVD, especially in combination with another risk factor, smoking habits.

Adult↗
PubMed2001

Orthodontic tooth movement and de novo synthesis of proinflammatory cytokines.

Interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) are proinflammatory cytokines that are thought to play a role in bone remodeling, bone resorption, and new bone deposition. In the present work, in situ hybridization was performed to measure the messenger RNA expression of IL-1beta, IL-6, and TNF-alpha at 3, 7, and 10 days after the application of orthodontic force on the maxillary first molars of 12 rats. The contralateral side and 3 untreated rats served as controls. Measurements of the messenger RNA expression were selected as the means to investigate the role of orthodontic force in de novo synthesis of proinflammatory cytokines. After the application of force, the induction of IL-1beta and IL-6 was observed to reach a maximum on day 3 and to decline thereafter. No messenger RNA induction of either cytokine was measured in the control teeth. The messenger RNA expression of TNF-alpha was not detected at any time point of this study in the experimental or contralateral sides or in the control animals. Our data support the hypothesis that these proinflammatory cytokines may play important roles in bone resorption after the application of orthodontic force.

Animals↗
PubMed2001

The effect of hyaluronan on bone and soft tissue and immune response in wound healing.

BACKGROUND: The aims of this study were to investigate the anti-inflammatory effect and the effect on bone regeneration of hyaluronan in surgical and non-surgical groups. METHODS: In each of 15 individuals, 2 teeth with defects of similar character and magnitude in the upper or lower jaw were chosen. There were at least 2 teeth between the test and the control sites. In the surgical group, a bioabsorbable membrane was used for both test and control sites, and hyaluronan was placed in the intrabony pocket of the test site. In the non-surgical group, the periodontal pockets were scaled and hyaluronan was administered 3 times with an interval of 1 week in the test pockets. Alveolar bone height and bone healing patterns were analyzed using digital intraoral radiographs. Measurements of bone height were performed in the original digital black-and-white radiographs to obtain quantitative data on bone gain or loss. Bone healing patterns were studied with color-coded radiographs, using specially designed software in a personal computer with subsequent combinations of radiographs. Gingival crevicular fluid immunoglobulin (Ig)G, C3, and prostaglandin E2 (PGE2) responses; periodontal probing depth; bleeding on probing; and the presence of plaque were studied to evaluate the anti-inflammatory effect. Data were obtained at baseline before treatment, and at 2 weeks, and 1, 3, 6, and 12 months after treatment. RESULTS: For the surgical treatments, bone height was increased in the test group treated with hyaluronan (mean value 2.2%, corresponding to an average increase of approximately 0.5 mm) and reduced in the control group (mean value -1.8%, corresponding to an average decrease of approximately - 0.4 mm) (P<0.05) after 12 months. For the non-surgical treatments, bone height was reduced by a mean value of -1.1% (corresponding to an average decrease of approximately -0.25 mm) in the test group treated with hyaluronan and -3.3% (corresponding to an average decrease of approximately -0.75 mm) in the control group after 12 months (N.S.). According to the digital color-coded radiographs, the test sites in the surgical and non-surgical groups showed apposition of bone minerals. Immune responses showed no differences during the 12 months studied for the surgical and non-surgical sites. Mean periodontal probing depths were reduced between 2.5 mm and 4.1 mm in the surgical and non-surgical groups. CONCLUSIONS: The observed difference in bone height between test and control sites in the surgical group after 12 months was less than 1 mm, which was only detectable on radiographs. No statistical difference was found on radiographs in the non-surgical group, where a decrease in bone height was found for both groups after scaling. Probing depth reduction after the surgical treatment, as well as after scaling and root planing, was as expected. Hyaluronan in contact with bone and soft tissues had no influence on the immune system in this study. Further studies are needed to determine the extent to which hyaluronan can lead to clinically significant healing of periodontal lesions.

Absorbable Implants↗
PubMed2000

Orthodontic movement induces high numbers of cells expressing IFN-gamma at mRNA and protein levels.

Cytokines are important signaling proteins that are liberated during immune challenges and exhibit many modulatory activities. However, their role in periodontal modeling during orthodontic tooth movement is not fully understood. The aim of this study was to analyze effects of mechanical force during orthodontic tooth movement, in the pressure zone, on the induction of interferon-gamma (IFN-gamma) as a proinflammatory cytokine of Th1 type and interleukin-4 (IL-4)/IL-10 as anti-inflammatory cytokines of Th2 type. In 12 Wistar rats 40-45 days old, the maxillary first molar was moved mesially by means of a closed coil spring for 3, 7, and 10 days. The contralateral side served as a control. IFN-gamma, IL-4, and IL-10 mRNA were determined by in situ, hybridization, and protein levels of IFN-gamma was measured by immunohistochemistry. Induction of IFN-gamma at both mRNA and protein levels was significantly higher on the experimental side than on the contralateral control side on day 3. The signal gradually became stronger on day 7 and remained high on day 10. Cytokines of the Th2 type (IL-4 and IL-10) were not detected at all examined time points in both pressure and contralateral control sides. Considering the potential immunoregulatory roles played by IFN-gamma, our data suggest that IFN-gamma may be involved in periodontium remodeling during orthodontic tooth movement.

Animals↗
PubMed1999

Chemokines are upregulated during orthodontic tooth movement.

In the early stage of orthodontic tooth movement, an acute inflammatory response characterized by the migration of leukocytes occurs. This response suggests the presence of specific chemotactic signals that may play a role in the mechanism of bone remodeling, in particular in resorption. The aim of the present study was to explore the induction of potential chemokines at the resorption side during orthodontic tooth movement. Monocyte chemoattractant protein-1 (MCP-1), regulated on activation normal T cell expressed and secreted (RANTES), and macrophage inflammatory protein-2 (MIP-2) were examined by in situ hybridization using radioactive synthetic oligoneucleotide probes. Mesial movement of the upper first molars was performed with a fixed appliance for 3, 7, and 10 days. The results demonstrated that MCP-1, RANTES, and MIP-2 were highly expressed during orthodontic movement. On day 3, MCP-1 showed maximum induction in the pressure zone, followed in intensity by RANTES and MIP-2, although not in the contralateral control side. The induction of these chemokines had declined on day 7 and reached low levels on day 10. Our data suggest that chemokines are induced early in the application of force, and such induction may contribute to the early inflammatory response that may be responsible in part for the ensuing bone remodeling.

Animals↗
PubMed1998

Augmented levels of macrophage and Th1 cell-related cytokine mRNA in submandibular glands of MRL/lpr mice with autoimmune sialoadenitis.

MRL/Mp-lpr/lpr (MRL/lpr) mice spontaneously develop destructive inflammation of the salivary and lachrymal glands resembling Sjögren's syndrome (SS), representing an animal model to study this disease. We used in situ hybridization with synthetic radiolabelled oligonucleotide probes to examine expression of mRNA encoding pro- and anti-inflammatory cytokines in submandibular glands of 2, 3, 4 and 5-month-old MRL/lpr mice. Phenotypic composition of submandibular gland infiltrates was evaluated by immunohistochemistry. Cells expressing tumour necrosis factor-alpha (TNF-alpha), IL-1beta, IL-6 and IL-12 mRNA were strongly up-regulated at about the time of onset of sialoadenitis, suggesting a role of these cytokines in development of the disease. Interferon-gamma (IFN-gamma) and cytolysin mRNA-expressing cells were gradually up-regulated over the disease course up to 5 months of age, the time when sialoadenitis is at its height, favouring a role of these cytokines in progression of the disease as well. Low levels of IL-10 and transforming growth factor-beta (TGF-beta) mRNA-expressing cells were observed at 2, 3 and 4 months of age, and were almost undetectable at 5 months. Maximum levels of CD4+, CD8+ and interdigitating/dendritic cells, as well as of MHC class II and MHC class I expression were seen at 3 months, with CD4+ outnumbering CD8+ cells. Maximum levels of macrophages were seen at 4 months of age. These data argue for a major role of the proinflammatory cytokines TNF-alpha, IL-1beta, IL-6, IL- 12, IFN-gamma and cytolysin in initiation and perpetuation of autoimmune sialoadenitis in MRL/lpr mice, probably in conjunction with an insufficiency of the anti-inflammatory cytokines TGF-beta and IL-10.

Animals↗
PubMed1998

Coordinate up-regulation of the beta-chemokine subfamily in autoimmune sialoadenitis of MRL/lpr mice.

Mononuclear cell (MNC) infiltration of the salivary and lacrimal glands is a major feature in Sjogren's syndrome (SS) and its animal model, murine autoimmune sialoadenitis (MAS). To investigate factors that influence selective infiltration by MNC of submandibular glands in young and adult MRL/lpr mice with MAS, expression of mRNA encoding the beta-chemokines monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and regulated upon activation, normal T-cell expressed and secreted (RANTES) was investigated by in situ hybridization. MCP-1 protein production was also evaluated by immunohistochemistry. Young mice with MAS showed an early up-regulation of mRNA expression for MCP-1, MIP-1beta and RANTES, while MIP-1alpha mRNA expression was not affected. Adult mice with MAS showed a further up-regulation of mRNA expression for MCP-1, MIP-1beta and RANTES, and a remarkably strong up-regulation for MIP-1alpha. Immunohistochemistry revealed that MCP-1 protein production paralleled MCP-1 mRNA expression in both young and adult mice. These observations implicate MCP-1, MIP-1beta and RANTES as potential chemokines in induction of MAS, and MCP-1, MIP-1beta, RANTES and prominently MIP-1alpha in progression and perturbation of MAS.

Animals↗
PubMed1993

Significance of some variables on interproximal alveolar bone height based on cross-sectional epidemiologic data.

The objective of the study was to analyze the significance of some variables on interproximal alveolar bone height, based on cross-sectional epidemiologic data from a Swedish survey conducted in 1983-1984, in the northern medical care district of Alvsborg county. 723 dentate individuals (92% of the randomly selected dentate individuals) with complete anamnestic, clinical and radiographic documentation were included in the statistical analyses. The computerized method used to measure interproximal alveolar bone height as a % of root length (B/R) provided data at each measurable interproximal surface of the individual teeth. On the population basis, a multivariate linear regression analysis showed that: (i) mean B/R values did not differ significantly between men and women, (ii) B/R value decreased with increasing age at a linear rate of 0.26% (0.04 mm) per year of age, (iii) the higher the calculus index value, the lower the mean B/R value, (iv) the higher the plaque index value, the higher the mean B/R value, (v) level of education, dentist attendance frequency and prevalence of defective margins of dental restorations did not show any statistically significant association with B/R, (vi) individuals attending the dental hygienist less than once every 2 years had higher mean B/R value than individuals attending the dental hygienist at least once every two years, and (vii) current smokers exhibited significantly lower mean B/R value than former and non-smokers. Individuals smoking more than 5 g of tobacco per day had lower mean B/R values than individuals smoking between 1 and 5 g of tobacco per day. There was no statistically significant relationship between snuffing and B/R.

Adult↗
PubMed1993

The effect of changed smoking habits on marginal alveolar bone loss. A longitudinal study.

Tobacco smoking is a factor claimed to be of influence on alveolar bone loss. The purpose of the present study was to investigate whether the effect of changed smoking habits is associated with the progress of proximal marginal alveolar bone loss as measured on intraoral radiographs. The study comprised 349 individuals with twenty or more remaining teeth examined in 1970 and 1980. The bone loss in the period was measured as the difference in the ratios "bone height/root length" at proximal tooth sides between the two examinations. It was found that the marginal bone loss in "Non smokers in 1970 and 1980" was as a mean 3.9 per cent of the root length. The corresponding value among "Smokers 1970 and 1980" was 6.0 per cent. The difference is statistically significant (p = 0.001). In individuals who had given up smoking during the 10-year period (bone loss: 4.4 per cent) as compared with those who had smoked regularly, the progression of bone loss was significantly (p < 0.05) retarded. The result is in agreement with the hypothesis that giving up smoking produces favourable effects also with regard to the attachment of the teeth in the jaw-bone.

Adult↗
PubMed1991

Marginal alveolar bone height in an adult Swedish population. A radiographic cross-sectional epidemiologic study.

The purpose of the present cross-sectional epidemiologic study was to assess the interproximal alveolar bone level within the dentition of 732 randomly selected adult individuals, stratified according to gender and age. Full mouth series of periapical radiographs were used for the assessments of the relation alveolar bone height/root length (B/R). A computer/digitizer recording method was utilized for the assessments. The results were presented as (i) mean values per age group and gender, (ii) mean frequency of subjects with sites exceeding certain thresholds of bone loss and (iii) cumulative frequencies of subjects with various number and percentual proportion of sites in relation to different B/R-ratio intervals. The results showed a reduction in mean alveolar bone/root ratio with age. The women had a significantly more favourable mean B/R-ratio than men in the ages above 40 years; the women had, however, more missing sites above age 60 years. By older age, there was observed an increased variation between individual mean B/R-ratios. Only a few subjects had a mean B/R-ratio less than or equal to 50%. A subfraction of the subjects in the different age groups had greater than 20% of their sites below a B/R-ratio of 60%. This fraction increased with age.

Adult↗
PubMed1991

Gingival fluid and tissues around successful titanium and ceramic implants. A comparative clinical, laboratory, and morphologic study.

The gingival tissue reactions around 19 titanium implants (Brånemark System) and 6 ceramic implants (Frialit) were studied by using established variables for monitoring periodontal status. Natural teeth in the same or the opposite jaw served as controls. Both clinical and laboratory examinations showed healthy gingival status. No differences in soft-tissue reactions between the two types of implant or between the implants and the natural teeth were registered.

Adult↗
PubMed1990

Spirochaetes and granulocytes at sites involved in periodontal disease.

Eighty-six men and 63 women with periodontitis participated in this investigation, at the start of which clinical indices were recorded and the pocket contents from one periodontally involved site for each patient were analysed. The numbers of spirochaetes, other motile microorganisms, non-motile filaments, rods or cocci and of granulocytes, monocytes and epithelial cells were determined. After non-surgical treatment 98 patients (P-group) were unsuccessfully and 51 (C-group) were successfully treated. At baseline the P-group had significantly higher numbers of spirochaetes (p = 0.0001) and polymorphonuclear leucocytes (p = 0.0256) than the C-group. The number of rods was statistically higher in the C-group (p = 0.0254). There was no significant difference between the groups with respect to the number of remaining teeth, plaque or calculus scores. Significantly higher values were found in the P-group for bleeding on probing (p = 0.0434), number of pockets greater than or equal to 5 mm (p = 0.0001), mean pocket depths (p = 0.0001), percentage bone loss per site (p = 0.0001) and the number of sites with greater than or equal to 20% bone loss on radiographs (p = 0.0001).

Bacteria↗
PubMed1990

The approximal bone height and intrabony defects in young adults, related to the salivary buffering capacity and counts of Streptococcus mutans and Lactobacilli.

Using a computerized technique the bone height and prevalence of approximal periodontal intrabony defects were assessed on posterior bite-wing radiographs from 151 young adults. The results were related to the buffering capacity and counts of Streptococcus mutans and lactobacilli in whole stimulated saliva. The mean distance from the cement-enamel junction to the alveolar bone crest was greater in the high buffering group than in the low buffering group (p less than 0.05), and particularly in non-smokers (p less than 0.01). Intrabony defects were more common in the low buffering group (p less than 0.05) and in women (p less than 0.001).

Adult↗
PubMed1990

The effect of systemic metronidazole after non-surgical treatment in moderate and advanced periodontitis in young adults.

The effect of adjunctive systemic metronidazole was studied in patients with moderate and advanced periodontitis recalcitrant to comprehensive non-surgical treatment. The material originated from a randomly selected part of the population aged 31 to 40 years. After non-surgical treatment of 149 patients, 98 with persisting pathological pockets greater than or equal to 5 mm (52 men and 46 women) became the subjects for the study. Clinical parameters were registered and pocket contents subjected to laboratory analysis. The subjects were randomized into two groups according to a code list known only by the manufacturer and the statistician. The test group took three 400 mg metronidazole tablets daily for 1 week and the control group took placebo tablets. Reassessment 6 months later showed statistically significant clinical improvement, with a reduction in the number of sites greater than or equal to 5 mm in both test and control groups. Complete healing, with no pockets greater than or equal to 5 mm, was noted in 30% of the test group and 9% of the control group. The difference is statistically significant and shows the supplementary effect of adjunctive metronidazole in non-surgical treatment of moderate and advanced periodontitis.

Adult↗
PubMed1989

Prevalence of interproximal periodontal intrabony defects in an adult population in Sweden. A radiographic study.

The aim of this study was to determine the prevalence and localization of interproximal periodontal intrabony defects (IPIDs) in the total adult population of a Swedish county. On each interproximal tooth surface (third molars excluded) in 733 randomly selected dentate individuals aged 20 years and over, one examiner recorded from x5-magnified periapical radiographs, the presence or absence of IPID with a width and depth of at least 5 and 10 mm, respectively, representing 1 and 2 mm unmagnified. Intra-examiner reproducibility determined from double recordings was substantial (kappa = 0.66). Recordings of IPID were compared with those performed by 24 specialist periodontists using their own diagnostic criteria. IPIDs were recorded in 32% of the 733 examined individuals; the number of defects per individual ranged from 1 to 15. The prevalence of IPID increased with increasing age and IPID occurred more frequently in men than in women. IPID was observed more frequently on mesial than on distal tooth surfaces, whereas there was no difference between maxillary and mandibular tooth surfaces. Symmetrical localizations of IPID in relation to the sagittal plane were observed.

Adult↗
PubMed1988

Measurement of gingival swelling from dental casts by generation of a moiré pattern with laser light.

The aim of the study was to develop a sensitive measuring method enabling direct evaluation of gingival swelling to be made as registered on dental casts. On two separate occasions, when different degrees of severity of gingival inflammation were present in the same subject, reversible hydrocolloid impressions were taken of the mandible. The casts obtained were located successively in identical three-dimensional relationships in a field of interference fringes generated by two intersecting beams of collimated helium-neon laser light, and were photographed. The evaluation of the moiré pattern obtained directly by superimposition of the two images of the surface studied indicated that a decrease in gingival height of 0.38 mm in the direction of the camera had occurred between the two occasions. The use of a computer-based image-processing system considerably improved the visibility of the pattern. The reproducibility of the impression technique, as well as the relocation and superimposing techniques, proved satisfactory at the moiré resolution used (0.19 mm). The method has potential application in clinical experimental research, and therefore warrants further evaluation.

Adult↗
PubMed1988

A computerized system to measure interproximal alveolar bone levels in epidemiologic, radiographic investigations. I. Methodologic study.

The aims of the study were to adapt a computerized system to epidemiologic conditions, for rapid full-mouth measurements of alveolar bone levels from X5-magnified periapical radiographs and to analyze the variations in measurement due to different system components. Full-mouth measurements of interproximal alveolar bone height in percentage of root and tooth lengths were completed within an average time of 15 min per set of radiographs. An analysis of variance showed that the examiner variation in measurement of a linear scale distance was 0.02 mm. The measurement accuracy was different for different distances; each distance (d) measured with this system should therefore be calibrated with the equation Y = -0.007-0.014 (log3d-1.50), where Y is the estimate of measurement accuracy. The present computerized system enabled rapid recordings and demonstrated good measurement precision and accuracy; these are valuable features in epidemiologic investigations.

Alveolar Process↗