| 1. |
- Almståhl, Annica, 1973, et al.
(författare)
-
Oral microflora in subjects with reduced salivary secretion
- 1999
-
Ingår i: Journal of Dental Research. - 0022-0345 .- 1544-0591. ; 78:8, s. 1410-1416
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract. It is generally assumed that a decreased salivary secretion rate will promote plaque accumulation and increase the risk for caries, gingival inflammation, and mucosal infections. In this study, the effect of hyposalivation on the oral microflora was examined. The following microorganisms were analyzed in rinsing samples from 14 subjects with hyposalivation: the total number of anaerobically growing micro-organisms, alpha-hemolytic streptococci, mutans streptococci, lactobacilli, Fusobacterium nucleatum, Prevotella intermedia/Prevotella nigrescens, Staphylococcus aureus, Candida albicans, and enterics. The study group, age 53 ± 7 years, had no history of radiation therapy and showed no signs of inflammation in their salivary glands on biopsy. All were dentate with a mean of 24 ± 3 teeth. Their salivary secretion rates were 0.03 ± 0.02 mL/min (unstimulated) and 0.84 ± 0.65 mL/min (stimulated). The control group was matched to the hyposalivation group according to age, sex, and number of teeth. There was a significantly increased number of lactobacilli, and a tendency, not statistically significant and with large variations within the groups, toward a higher proportion of mutans streptococci and a lower proportion of alpha-hemolytic streptococci in the hyposalivation group. The presence of micro-organisms associated with gingival inflammation and mucosal infections was comparable with that in the healthy controls. The results indicated that a low salivary secretion rate mainly promotes a flora associated with the development of caries.
|
|
| 2. |
- Brandsten, C, et al.
(författare)
-
Expression of collagen alpha1(I) mRNA variants during tooth and bone formation in the rat
- 1999
-
Ingår i: Journal of dental research. - : SAGE Publications. - 0022-0345 .- 1544-0591. ; 78:1, s. 11-19
-
Tidskriftsartikel (refereegranskat)abstract
- Collagen al(I) mRNA is composed of two variants of 5 and 6 kb, differing in the length of the 3' untranslated region. In this work, the nucleotide sequences of the two rat mRNA variants were compared, and their expression pattern in cells forming bone, dentin, and cementum were analyzed. The sequences were determined from cDNA inserts of tooth and bone libraries plus directly from PCR fragments, obtained from bone. A total of 5721 bases of the rat collagen α1(I) sequence from cDNA of tooth and bone was determined. All sequences of the short variant were represented in the long variant. Only the alternatively poly-A additions gave rise to the variants in hard tissue. Two oligonucleotides were chosen as probes, one of which recognized, on Northern blots, the two bands of 5 and 6 kb, and the other the 6-kb variant only. The oligonucleotides were used in in situ hybridization experiments, for study of the distribution of the variants in different extracellular matrix-forming cells. Osteoblasts, odontoblasts, and cementum-associated cells were closely examined in sections from rat maxillae from 2 to 25 days of age. A similar or identical pattern of mRNA expression was observed with both oligonucleotides, indicating that the two mRNA variants were co-expressed in all cases.
|
|
| 3. |
- Cederbrant, Karin, et al.
(författare)
-
In vitro Lymphoproliferative Assays with HgCl2 Cannot Identify Patients with Systemic Symptoms Attributed to Dental Amalgam
- 1999
-
Ingår i: Journal of Dental Research. - : SAGE Publications. - 0022-0345 .- 1544-0591. ; 78:8, s. 1450-1458
-
Tidskriftsartikel (refereegranskat)abstract
- Dental amalgam is suspected, by some exposed individuals, to cause various systemic psychological, sensory, and neurological symptoms. Since not all amalgam-bearers experience such reactions, an individual characteristic—for example, a susceptible immune system—might explain these conditions. In vitro lymphocyte proliferation is a valuable tool in the diagnosis of allergy. With HgCl2 as the antigen, however, the test is hampered, because Hg2+ can cause unspecific lymphocyte proliferation, optimal at 1.4 to 9.5 μg HgCl2/mL. Recently, the use of suboptimal HgCl2 concentrations (≤ 0.5 μg/mL) has been suggested to circumvent these problems. The main aim of this study was to investigate whether patients with systemic symptoms alleged to result from the presence of dental amalgam differ from healthy controls, with reference to in vitro lymphoproliferative responses to HgCl2 ≤ 0.5 μg/mL. Three different test protocols—lymphocyte transformation test (LTT) in micro- and macro-cultures, and the memory lymphocyte immunostimulation assay (MELISA®)—were used. Other immune parameters—such as a standard patch test for dental materials, the number of T- and B-lymphocytes, monocytes, granulocytes, and NK cells in peripheral blood, allergic symptoms, and predisposition-were also investigated. Twenty-three amalgam patients, 30 healthy blood donors with amalgam, ten healthy subjects without amalgam, and nine patients with oral lichen planus (OLP) adjacent to dental amalgam and a positive patch test to Hg0 were tested. None of the investigated immune parameters revealed any significant differences between amalgam patients and controls. The sensitivity of in vitro lymphocyte proliferation ranged from 33 to 67%, with the OLP patients as a positive control group, and the specificity from 0 to 70% for healthy controls with a negative patch test to Hg°. Thus, despite the use of HgCl2 ≤ 0.5 μg/mL, a high frequency of positive results was obtained among healthy subjects with or without dental amalgam. Consequently, in vitro lymphocyte proliferation with HgCl2 cannot be used as an objective marker for mercury allergy in dental amalgam-bearers.
|
|
| 4. |
|
|
| 5. |
- Hägglin, Catharina, 1955, et al.
(författare)
-
Variations in dental anxiety among middle-aged and elderly women in Sweden: a longitudinal study between 1968 and 1996.
- 1999
-
Ingår i: Journal of dental research. - : SAGE Publications. - 0022-0345 .- 1544-0591. ; 78:10, s. 1655-61
-
Tidskriftsartikel (refereegranskat)abstract
- Cross-sectional studies have shown that older individuals are significantly less dentally anxious than younger ones. However, research has not been able to show if this is a cohort effect or an effect of fear declining with age. If it is a cohort effect, dental anxiety among the elderly may pose a greater-than-expected problem for the providers of dental services. With the exception of longitudinal studies in children and a three-year follow-up on adults, no truly longitudinal epidemiological studies concerning dental anxiety have been performed. The aim of this project was to investigate how dental anxiety changes with aging. In a longitudinal population study of women in Göteborg, Sweden, starting in 1968, 1462 women aged 38 to 54 participated. A representative subsample of 778 women took part in a psychiatric examination where an investigation of dental anxiety was included. The same questions were also included when these women were re-examined in 1974, 1992, and 1996. Three hundred seventy-five women were still eligible for investigation in 1996. In 1968-69, 48 (12.8%) of the participating women assessed themselves as "very afraid" or "terrified" when visiting the dentist, and in 1996 the frequency was 21 (5.6%) among the same women. In 1968-69, 180 women (48%) reported no dental anxiety when visiting the dentist, and 28 years later the frequency was 230 (61%). In the three youngest age groups, dental anxiety decreased significantly (p < 0.001) over the 28-year period. Older compared with younger women reported significantly less dental anxiety, and this was an age effect rather than a cohort effect. Thus, this longitudinal study supported the hypothesis that dental fear, like many other general and specific phobias, declines with age.
|
|
| 6. |
- Karjalainen, S, et al.
(författare)
-
Salivary cholesterol of healthy adults in relation to serum cholesterol concentration and oral health
- 1997
-
Ingår i: Journal of Dental Research. - : SAGE Publications. - 0022-0345 .- 1544-0591. ; 76:10, s. 1637-43
-
Tidskriftsartikel (refereegranskat)abstract
- Salivary lipids are mostly glandular in origin, but some are believed to diffuse directly from serum. This diffusion and the role of salivary lipids in oral health have scarcely been studied. Therefore, the serum and saliva cholesterol concentrations and oral health were analyzed in a group of healthy adults (n = 139; 64 men and 75 women; 34.2 +/- 5.2 yrs). Paraffin-stimulated whole saliva was collected, centrifuged (10,000 x g; 30 min, 4 degrees C), and lyophilized, and the cholesterol and other neutral lipids were extracted, separated by thin-layer chromatography, and quantified. The mean +/- SD (range) of saliva cholesterol concentration was 1.20 +/- 0.75 (0.02-5.46) mumol/L, and the saliva cholesterol level of men (1.36 +/- 0.85 mumol/L) was significantly higher than that of women (1.06 +/- 0.64 mumol/L; p < 0.05). Weak positive correlations between saliva and serum cholesterol concentrations and saliva cholesterol and serum non-high-density lipoprotein cholesterol concentrations were found (r = 0.22, p < 0.05; r = 0.28, p < 0.005, respectively). The saliva cholesterol assay detected subjects with high (> or = 6.5 mmol/L) serum cholesterol values, with sensitivity and specificity values of 100% and 29%, respectively. A positive correlation between the body mass index and the level of saliva cholesterol concentration was also found (r = 0.31 p < 0.01). Oral health, microbial counts, or saliva flow rate revealed no differences in subjects with low and high salivary cholesterol level. We conclude that, in healthy adults, saliva cholesterol concentration reflects serum concentration to some extent and can be used to select individuals with high serum cholesterol levels.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Nilsson, JA, et al.
(författare)
-
Toxicity of formaldehyde to human oral fibroblasts and epithelial cells: influences of culture conditions and role of thiol status
- 1998
-
Ingår i: Journal of dental research. - : SAGE Publications. - 0022-0345 .- 1544-0591. ; 77:11, s. 1896-1903
-
Tidskriftsartikel (refereegranskat)abstract
- The toxicity of formaldehyde, a monomer released from certain polymeric dental materials, was studied in cultured human oral fibroblasts and epithelial cells. The influences of growth conditions were evaluated for both cell types, as well as the role of the internal and external thiol states. A one-hour exposure to formaldehyde decreased the colony-forming efficiency (CFE) of both cell types in a concentration-dependent manner, although the toxicity varied up to 100-fold with the conditions. Clearly, the presence of serum and the thiol cysteine counteracted the toxicity in fibroblasts. Similarly, pituitary extract and cysteine, or a mixture of amino acids and ethanolamines, counteracted the formaldehyde toxicity in serum-free cultures of epithelial cells. In contrast, a growth-promoting surface matrix of fibronectin and collagen did not influence the formaldehyde toxicity, as shown by both the CFE assay and a dye reduction assay. Further, a short-term change to the various growth media per se with or without the supplements serum or cysteine did not significantly alter the CFE. Analysis of the thiol state demonstrated significant differences between epithelial cells and fibroblasts, i.e., comparatively lower cellular levels of the free low-molecular-weight thiols glutathione and cysteine in fibroblasts. This result correlated to significantly higher formaldehyde toxicity in the fibroblasts than in the epithelial cells. Taken together, the results indicated the cytoprotective function of both intracellular and extracellular thiols toward formaldehyde, as well as the usefulness of thiol-free and chemically defined conditions for toxicity assessments in oral epithelial cells and fibroblasts. We conclude that the combined use of a controlled external milieu and the presumed target cell type may be advantageous in evaluations of oral toxicity mechanisms or the toxic potency of dental materials, particularly those which, like formaldehyde, may react with thiols or amines.
|
|
| 10. |
|
|
