bluuebunny/crossref_metadata_2025 huggingface dataset:
Light microscopic and transmission electron microscopic study of initial phases of giant tubule formation in bovine dentin
Authors: DYNGELAND TROND
Published: October 2007

Abstract – Bovine tooth germs dissected from the mandible immediately after bleeding of the less than 1‐yr‐old calves (Bos taureus) were used to study the initial phases of giant tubule (GT) formation. Three stages could be discerned. Firstly, the initial manifestations were represented by loci about 150 μm apart in the axiomesiodistal plane along the pulpal border of the I00–200‐μm‐thick incisal dentin. Some of these loci showed only a blunt capillary loop and associated cells, whereas in most others there was a 50–100‐μm‐wide dense matrix consisting of coarse collagen fibrils and showing a metachromatic staining reaction to toluidine blue. Fibroblasts lined this matrix, and a capillary loop was always present underneath. Both kinds of GT origins were eventually circumvented by the odontoblasts situated incisal to them. The matrices became enclosed in the dentin. In the second stage, the GT grew in length as new dentin was formed. In this stage the vascular loops and the adjoining fibroblasts remained stationary within the GT lumina relative to the origins. In the third stage the GT vessels started to migrate pulpally relative to the origins. This seemed to be the result of a sequestration of the most incisal portions of the vascular loops. In this last stage the formation of collagen fibrils in the GT lumen incisal to the vessel loops started.
Column‐like structures following the course of dentinal tubules In bovine, red deer, and rat teeth
Authors: HALS EINAR , DYNGELAND TROND
Published: October 2007

Abstract – A material of bovine, red deer, and rat incisors was investigated, with emphasis on the bovine teeth. Both ground sections and paraffin wax sections of demineralized material were used. The sections were investigated by ordinary and polarized light microscopy and contact microradiography. In the bulk of the dentin irregular column‐like light structures, alternating with largely similar, but dark, columns, followed the course of the dentinal tubules from the pulpal border to just below the mantle dentin. Each column, 10–100 μm in diameter, contained a highly varying number of tubules. The difference between light and dark columns was mainly related to the intertubular dentin of the globules of which they were composed. Light columns were slightly more mineralized than the dark ones and seemed to contain fewer GAGs, but more glycoproteins. A difference in fiber direction between light and dark columns was also evident. To the authors' knowledge these structures have not attracted the attention of previous workers.
Oral lesions of lupus erythematosus patients in relation to other chronic inflammatory oral diseases: an immunologic study
Authors: SANCHEZ ROSARIO , JONSSON ROLAND , AHLFORS EVA , BÄCKMAN KERSTIN , CZERKINSKY CECIL
Published: October 2007

Abstract – The nature and distribution of mononuclear cells in non‐ulcerated oral lesions of discoid (DLE) and systemic lupus erythematosus (SLE), were investigated and compared to other chronic inflammatory oral diseases (lichen planus (LP), contact lesion (CL), unspecified inflammation (UI), geographic tongue (GT), and leukoplakia (LK). For this purpose an immunoperoxidase technique based on staining with monoclonal antibodies was employed. In most LE specimens examined infiltrating cells consisted predominantly of a mixture of T cells (Leu 3a+ and Leu 2a+) that were distributed in the lamina propria, the submucosa, and occasionally also in the epithelium. In general, only few B cells were detected while macrophages were more frequent. In all LE specimens examined β2‐microglobulin expression was observed on a large proportion of cells including infiltrating mononuclear cells as well as resident keratinocytes. In addition, most infiltrating cells displayed MHC Class II antigens according to a pattern HLA‐DR>DQ>DP. Interestingly, expression of Class II antigens was also observed on epithelial keratinocytes but was restricted to HLA‐DR and ‐DP gene products (DR> >DP). HLA‐DQ expression was never observed on keratinocytes. In most LE specimens studied a small proportion (<5%) of inflammatory cells had detectable interleukin‐2 receptors (IL‐2R) and/or transferrin receptors (transf‐R). However, expression of transf‐R was also observed on basal epithelial cells, being more pronounced in DLE than in SLE lesions. The above staining patterns observed in LE lesions, when compared to other chronic inflammatory oral lesions, did not disclose any striking differences that could support the specific diagnosis of LE. However, the findings of Class I and II MHC gene products on oral keratinocytes suggest an important accessory role for these cells in directing the migration of activated lymphoid cells in the epithelium in chronic inflammatory lesions of the oral mucosa.
Influence of dentin‐bonding agents and a glass‐ionomer base on the cervical marginal seal of Class II composite restorations
Authors: SHORTALL ADRIAN , ASMUSSEN ERIK
Published: October 2007

Abstract – The cervical dentin marginal seal of Class II composite resin restorations was assessed in vitro. Elimination of marginal contraction gaps by specific dentin‐bonding treatment led to a reduction in the extent of cervical microleakage as assessed by a silver staining method. The use of a “sandwich” technique employing a glass‐ionomer material to seal the cervical cavity margin did not prevent cervical microleakage occurrence.
Two complementary methods of assessing periodontal bone level in rats
Authors: KLAUSEN BJARNE , EVANS RICHARD TODD , SFINTESCU CORNELIA
Published: October 2007

Abstract— Several methods have been applied to measure periodontal disease in rats. The purpose of the present study was to test the reproducibility of a morphometric and a radiographic method and to describe the correlation between the two methods. Periodontal bone loss on 25 denfleshed rat heads was assessed under microscope by measuring the distances from the cementoenamel junction to the alveolar bone crest at 36 buccal sites in each animal. On magnified radiographs from 25 rat mandibles periodontal bone support was expressed by the ratio apex‐deepest bony defect: apex‐cusp tip distally on first molars. All measurements were performed blind and in duplicate on two separate occasions. The bilateral 95% confidence limits for the error of method of measurement were estimated from the t‐distribution. In a second experiment 50 rat heads were assessed by both methods, and the correlation between the recordings was estimated by the Spearman rank correlation analysis. Compared to the considerable total variation in the material, the variations due to error of methods of measurement were small, i.e. the reproducibility of both methods was satisfactory. A significant correlation was found between the methods. Since the morphometric method mainly measures horizontal bone loss, whereas the radiographic method detects intrabony interproximal defects, it is concluded that future studies would benefit from applying both methods to assess alveolar bone loss in rats.
Outer membranous vesicles and leukotoxic activity of Actinobacillus actinomycetemcomitans from subjects with different periodontal status
Authors: TERVAHARTIALA BARBARA , UITTO VELI‐JUKKA , KARI KIRSTI , LAAKSO TUULA
Published: October 2007

Abstract – Strains of A. actinomycetemcomitans (A.a) from juvenile periodontitis patients (JP), adult periodontitis patients (AP), and 14‐yr‐old healthy children were tested for the correlation between leukotoxin activity and the number of outer membranous vesicles measured in electron micrographs. To determine the potential for connective tissue destruction following the interaction of polymorphonuclear leukocytes (PMN) with the bacteria, the lysosomal release of neutro‐phil elastase was assessed. The highest potential to kill leukocytes and to release lysosomal elastase from them was observed in the strains isolated from JP patients. No correlation existed between leukotoxic activity and the number of outer membranous vesicles per bacterium when the data from A.a. strains from all sources were combined. Furthermore, no significant differences were found between the numbers of outer membranous vesicles in the three groups tested. The only significant correlation between the number of vesicles and leukotoxicity was found in the A.a. strains derived from the mouths of healthy children.
Utilization of amino acids and peptides by Fusobacterium nucleatum
Authors: BAKKEN VIDAR , HÖGH BENTE T. , JENSEN HARALD B.
Published: October 2007

Abstract – Fusobacterium nucleatum strains ATCC 10953, Fevl, F1, F3, and F6 utilized amino acids, in particular glutamate, histidine, and aspartate were common to all strains. Strain differences were observed in the utilization of threonine, serine, lysine, tyrosine, and methionine, and only strain ATCC 10953 utilized all these amino acids. The glutamate and histidine pools were in all cases fully depleted before the other amino acids were attacked and at the same time all strains except 10953 started to utilize peptides at a noticeable rate. For strain Fevl, glutamyl‐and aspartyl‐containing peptides seemed to be of considerable nutritional importance, and this strain did not grow on a medium based on amino acids alone. On the other hand, strain 10953 did not utilize any peptides to a noticeable extent, and it could grow on an amino acid based medium.
Panoramic screening for dental anomalies assessed by professionals with identical and different backgrounds
Authors: HINTZE HANNE , WENZEL ANN , WILLIAMS STEPHEN
Published: October 2007

Abstract – The aim of the present study was to evaluate how dental professionals with identical and different backgrounds assess dental anomalies viewed on panoramic radiographs. 101 panoramic radiographs performed of 9‐to‐10‐yr‐old children were examined independently by three orthodontists and two radiologists. All observers agreed on the recording of number and identification of congenitally missing permanent teeth. The observers' assessments of malpositioned teeth, teeth in infraocclusion, and primary teeth with atypical/non root resorption varied, however, to a great extent. Two of the orthodontists seemed to report only major deviations from normality (in 38 and 51 of the children respectively) while one reported several more findings (in 85 children). The radiologists reported abnormal findings in 80 and 88 children respectively. In only three children were no dental anomalies reported by any observer. The inconsistent reporting of the majority of dental anomalies (except for agenesis) in children, even among members of subgroups with a similar educational background (e.g. orthodontists), substantiates the need for an evaluation of the expedience of panoramic screening.
Fluorescence from dentin and cementum in human mandibular second premolars and its relation to age
Authors: KVAAL SIGRID , SOLHEIM TORE
Published: October 2007

Abstract – Investigations were carried out to study the fluorescent properties of human dentin and cementum and their relation to age. One hundred mandibular second premolars were ground according to the “half tooth” technique. The intensity to the red fluorescence was measured during illumination of dentin and cementum with a green light. The results were analyzed with the use of the SPSS. The intensity of the fluorescent light recorded from cementum was stronger than that recorded from dentin. A paired t‐test showed no statistically significant left/right difference in fluorescence. Pearson's correlation coefficient indicated a strong relationship between age and fluorescence from dentin (r = 0.73) and from cementum (r =0.77). The sex of the individual had no significant influence on the fluorescence. Teeth removed from decreased individuals emitted fluorescence with a slightly stronger intensity than did teeth extracted from living patients. Regression analysis indicated a linear relationship between age and the fluorescence from either dentin or cementum. There was strong correlation between the intensity of the fluorescence and color estimates from the same teeth and the partial correlation coefficient was still statistically significant whtn controlling for the effect of age.
Phenotypic characterization of mononuclear cells and Class II antigen expression in angular cheilitis infected by Candida albicans or Staphylococcus aureus
Authors: ÖHMAN S.C. , JONTELL M. , JONSSON R.
Published: October 2007

Abstract – In the present study we characterized the phenotypes of infiltrating mononuclear cells in angular cheilitis lesions to further explore the pathogenesis of this disorder. Frozen sections from lesions infected by Candida albicans and/or Staphylococcus aureus were subjected to immunohistochemical analysis utilizing monoclonal antibodies directed to subsets of T‐lymphocytes, B‐lymphocytes, and macrophages. In addition, the expression of Class II antigens (HLA‐DP, ‐DQ, ‐DR), the interleukin 2‐ and transferrin‐receptors was studied on resident and infiltrating cells. An intense infiltration of T‐lymphocytes was accompanied by expression of Class II antigens on the epidermal keratinocytes in lesion infected by Candida albicans. The Staphylococcus aureus infected lesions desplayed a diffuse infiltration of T‐lymphocytes but virtually no expression of Class II antigen by epidermal keratinocytes. These observations suggest that the cell‐mediated arm of the immune system is involved in the inflammatory reaction of lesions infected by Candida albicans. In addition, the present study confirms that epidermal expression of Class II antigens is closely related to the type and magnitude of the infiltrating T‐lymphocyte. Finally, these findings indicate that the type of inflammatory reaction in angular cheilitis is primarily dependent on the isolated microorganism, although the clinical pictures of the disorder are virtually identical.
Effect of a slow release transcutaneous scopolamine application on salivary flow, pH, buffering action, and salivary levels of Streptococcus mutans and lactobacilli
Authors: ARNEBERG PAL , STORHAUG KARI , SANDVIK LEIV
Published: October 2007

Abstract— A motion sickness plaster releasing a powerful antisialogogic agent, scopolamine, was tested in a double blind clinical trial for its effect on salivary parameters in 14 healthy young men. The agent caused a decline in salivary flow rates, which was most pronounced during unstimulated conditions. Salivary pH and buffer capacity were also reduced. Salivary levels of Streptococcus mutans and lactobacilli showed a tendency to increase during 2 days on the antisialogogic agent, but the effect on S. mutans levels was not statistically significant.
Decrease of γ1 lattice constant with time in dental silver amalgam
Authors: JENSEN STIG JORGO
Published: October 2007

Abstract— As a measure of the mercury content of the γ1 phase in dental silver amalgam, the lattice constant of this phase in different amalgams was determined at various times after trituration. The lattice constants of amalgams prepared from alloys with a high silver content have lower values and show a steeper decline with time than amalgams with a low Ag‐content. Therefore, since a higher lattice constant presumably is associated with increased mercury vapor, the mercury vapor emission from amalgams with a low Ag‐content probably is greater than from amalgams with a high Ag‐content, especially during the first weeks after trituration.
Effect of a moderate vitamin A deficiency on saliva secretion rate and some salivary glycoproteins in adult rat
Authors: JOHANSSON INGEGERD , LUMIKARI MARIANNE , ERICSON THORILD
Published: October 2007

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.
Presence of mutans streptococci and various types of lactobacilli in interdental spaces related to development of proximal carious lesions
Authors: CROSSNER CLAES‐GÖRAN , CLAESSON ROLF , JOHANSSON TOMMY
Published: October 2007

Abstract – During a 2‐yr study period samples from saliva, the tongue, and 276 interdental spaces were obtained from 23 7‐yr‐old children in order to (a) relate the presence of lactobacilli in various oral sites to the occurrence of lactobacilli in saliva, and (b) relate the presence of mutans streptococci and various types of lactobacilli interdentally to the development of proximal carious lesions. The results showed an increased number of interdental samples containing lactobacilli with an increasing number of salivary lactobacilli. Furthermore, lactobacilli were never found interdentally without the presence of mutans streptococci, and lactobacilli proved to be the more suitable microorganism for prediction of proximal carious lesions. Neither the number nor the differentiation into different species of interdental lactobacilli seemed to be of importance, but simply whether they were present. The presence of lactobacilli probably reflects a caries‐inducing environment (etiologic microflora + fermentable carbohydrates), thus explaining their high predictive ability compared to their rather limited etiologic importance in the initiation of decay.
Characteristics of‐neutral proteases present in inflamed human gingiva
Authors: SUOMALAINEN KIMMO , SORSA TIMO , UITTO VELI‐JUKKA , VAUHKONEN MATTI , LINDY SEPPO
Published: October 2007

Abstract – The existing forms of neutral proteases present in inflamed human gingiva were examined. Neutral 2 M KCl extracts of inflamed human gingival tissue were fractionated by gel filtration on Sephacryl S‐200 and the fractions were assayed for collagenase, trypsin‐, chymotrypsin‐, and elastase‐like proteases. Apparent molecular weights of 80–85 kDa were obtained for trypsin‐, chymotrypsin‐, and elastase‐like proteases, and 70–75 kDa for latent collagenase. Further fractionation of high molecular weight proteases on Con A‐Sepharose revealed that, unlike collagenase, chymotrypsin‐, and elastase‐like proteases, the trypsin‐like protease was bound by the affinity column. Native human placental type IV (basement membrane) collagen was degraded by chymotrypsin‐like and elastase‐like proteases but not by the trypsin‐like protease. This degradation was inhibited by phenylmethyl sulfonyl fluoride and EDTA. The serine proteases also degraded efficiently denatured type I collagen. No correlation of the activities of trypsin‐like protease and the other proteolytic enzymes was found in extracts of 18 individual gingival specimens. Significant correlation, however, was noted between collagenase and gelatinase. The gingival culture studies showed that, while the highest activity of the trypsin‐, chymotrypsin‐, and elastase‐like enzymes were measured in medium during first days of the culture, collagenase and gelatinase activities increased up to the fourth day of culture and stayed high until the end of the culture. These results suggest that the neutral proteases that may participate in the periodontal tissue destruction are produced by different cell types of gingiva.
Muscular tenderness evaluated by surface EMG frequency analysis of isometric contractions
Authors: HAGBERG CATHARINA , HAGBERG MATS
Published: October 2007

Abstract – Myoelectric power spectrum analysis was used to compare muscular activity in the masseter and anterior temporal muscles between patients with tender masseter muscles and healthy controls. Surface EMG was recorded for 28 patients and nine controls while they were biting on a bite force transducer during a period of 10–15 s up to maximal effort (100% MVC). The mean frequency (MF) was calculated as a single estimate of the myoelectric power spectrum. Regression analyses of MF's for the masseter muscles versus the force level 0–60% MVC showed significantly less steep slopes of regression for the patients compared interindividually with the controls. As regards the anterior temporal muscles there was no significant difference between groups. One explanation for the difference in MF's for the masseter muscles between patients and controls is that the patients suffered an inhibition or difficulty in recruiting motor units. Different firing rate properties for motor units at high force levels (60–100% MVC) could be one reason for a significantly smaller decrease in MF for the patients' elevator muscles than for the controls.
Mandibular condyle lesions, jaw movements, and occlusal status in 15‐year‐old children with juvenile rheumatoid arthritis
Authors: KARHULAHTI TEIJA , RÖNNING OLLI , JÄMSÄ TAPIO
Published: October 2007

Abstract – The purpose was to determine the number and severity of lesions in the temporomandibular area and their association with occlusal status and mandibular movements, in 15‐yr‐old children afflicted with juvenile rheumatoid arthritis (JRA). The series comprised 121 JRA children, 78 girls and 43 boys, and a control group of 104 schoolchildren, 70 girls and 34 boys, taken for clinical examination. Of the JRA children, 55% had roentgenologically detectable lesions in the TMJ area. Lesions were found in 60% of the girls and in 42% of the boys, the ratio thus being 3:2. The largest group had grave lesions (48%), the second largest displayed flattening of the condyle (43%) and the smallest a flattened condyle with a minor lesion (9%). There were more bilateral lesions in the children with the severest lesions. Tendencies for Class II malocclusion, small vertical overbite and open bite were visible in the JRA children. Reduced maximal opening capacity, maximal protrusion, lateral movements of the mandible and pain in the TMJ area proved to be reliable signs predicting temporomandibular joint involvement in JRA children. Maximal mouth opening capacity was significantly restricted in the patients showing condylar lesions as compared with patients having no lesions or with controls. JRA children should be divided according to sex and the severity of the lesions. The JRA children without TMJ lesions had normal values for mandibular movements and were thus comparable to healthy children.
Identification of connective tissue components in healing rat gingiva
Authors: GREVSTAD HANS JACOB
Published: October 2007

Abstract – The aim of the study was to examine connective tissue fiber organization during healing of an incisional wound in rat molar gingiva. Forty rats 50 days old were divided into 10 experimental groups each comprising four animals. Following interdental incisions, healing periods of 11‐20 days, and then 3H‐proline injection, the animals were sacrificed and specimens prepared for light microscopy, autoradiography, and transmission electron microscopy. Isotope labeling with 3H‐proline occurred over newly formed collagen in the path of incision, while preexisting tissue was unlabeled. Ultrastructurally, preexisting and new tissue were identified by measurement of collagen fibril thickness. The spatial relationship between new and remaining fibrous tissue in the transitional zone suggests that reunion is established by side‐by‐side alignment of new and severed fibrils.
Oral radiographic screening in Danish children
Authors: HINTZE HANNE , WENZEL ANN
Published: October 2007

Abstract – The aim of the present study was to ascertain frequency and type of radiographic screening in the Danish Dental Service for children. A 5‐item questionnaire was sent to each department of public dentistry in the 275 communities of Denmark. A total of 269 questionnaires were returned, four unanswered. Radiographic screening examinations were done on 162 respondents. Of these, 25% had bitewing screening and 25% panoramic screening. Two types of routine radiographic examinations were performed on more than one third of the respondents. The most frequent combination for screening radiography was bitewing and panorama. Even though the risks included in the use of ionizing radiation for dental screening purposes may be considered negligible, it is still ethically correct to avoid unnecessary exposure by a careful selection of patients prior to radiography. As economic support for dental health care had been cut, the radiographic screening procedure must prove itself to be cost/effective to be kept unchanged.
Influence of heating rate in thermal expansion of dental phosphate‐bonded investment material
Authors: PAPADOPOULOS TRIANTAFILLOS , AXELSSON MARGARETA
Published: October 2007

Abstract – The thermal expansion of a phosphate‐bonded investment material was tested when three heating rates were used during the heating procedure. One of them was too low, one too high, and the third, in the middle. The examination was done through the fit of 12 MOD inlays and 12 full crowns in steel master dies. From the results it can be concluded that rates that are too fast must be avoided in the heating procedure, because they reduce the thermal expansion of the phosphate‐bonded investment material and thus produce castings with limited fit.
Glass ionomers in proximal cavities of primary molars
Authors: FORSTEN LENNART , KARJALAINEN SÁRA
Published: October 2007

Abstract – Proximal cavities with or without a dovetail were prepared in primary molars of 5‐7‐yr‐old children. The cavities were filled with either a traditional glass ionomer (Ketac‐Fil) or a cermet (Ketac‐Silver). A total number of 199 treated teeth were available for evaluation 5‐14 months after placement of the fillings. The percentage of success was 84% for Ketac‐Fil and 77% for Ketac‐Silver. There was no clear difference in rate success between the two different types of cavities.
Patients complaining about amalgam‐related symptoms suffer more often from illnesses and chronic craniofacial pain than their controls
Authors: MEURMAN JUKKA H. , PORKO CARITA , MURTOMAA HEIKKI
Published: October 2007

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.
Prevention of enamel demineralization adjacent to glass ionomer filling materials
Authors: FORSS HELENA , SEPPÄ LIISA
Published: October 2007

Abstract – In order to study the release of fluoride and prevention of enamel demineralization by different filling materials, standardized cavities were prepared in 80 extracted human molars. The cavities were filled as follows: 1. Fuji II F; 2. Ketac‐Fil; 3. Ketac‐Silver; 4. Silar. Twenty molars were used as controls (no filling). Enamel slabs with the fillings were subjected to 9 days of demineralization (30 min daily) and remineralization (artificial saliva, replaced daily). Fluoride release in the saliva was determined on days 1, 3, 5, and 9. Enamel fluoride content adjacent to the cavities was determined initially and after the de‐remineralization using the acid etch technique. On day 1, the largest amount of fluoride in the saliva was released by Fuji, but on day 9 the largest amount was released by Ketac‐Fil. Ketac‐Silver released significantly less fluoride than Fuji and Ketac‐Fil. The average initial fluoride content of enamel was 2200 ppm. After the test period, fluoride contents adjusted for biopsy depth were 1822, 1690, 1693, 1337, and 888 ppm in groups 1‐5, respectively. The amounts of phosphorus dissolved by the second acid etch were 28.9 (SE 2.6), 30.2 (2.0), 34.4 (2.8), 44.1 (2.7), and 42.2 (2.4) μg, respectively. Softening of surface enamel during the test period was clearly reduced in teeth filled with Fuji and Ketac‐Fil. The results show that glass ionomer materials release considerable amounts of fluoride and prevent demineralization of the adjacent enamel in vitro. Fuji and Ketac‐Fil seem to be more effective than Ketac‐Silver.
Effect of casting atmosphere on the quality of Ti‐crowns
Authors: SUNNERKRANTZ PÄR ANDERS , SYVERUD MORTEN , HERÖ HÅKON
Published: October 2007

Abstract – Ti has a strong affinity to elements like O, N, and C. During melting a non‐reacting crucible and vacuum and/or Ar‐gas protection therefore have to be used. If the impurity content becomes too high, the material turns hard and brittle. In the present work vacuum/Ar‐pressure casting of crowns has been carried out at different air pressure levels. Recording of hardness on cross‐sections of the castings and the degree of mold filling show that an air pressure level < 1 torr in the melting chamber and < 10 torr in the mold chamber is sufficient to obtain sound castings of a small size like a crown.
A 3‐year evaluation of Gluma and Gluma/Scotchbond for restoration of cervical erosions
Authors: VAN DIJKEN JAN W. V.
Published: October 2007

Abstract – Gluma and Gluma/Scotchbond were used in cervical abrasion/erosion lesions mediating a bond between a resinous restorative material and dentin. The lesions were restored without acid etching of enamel and without use of an intermediary layer of an enamel bonding agent. 142 restorations were placed. The restorations were evaluated clinically using the USPHS‐system at the baseline and every half year during a 3‐yr period. After 36 months the Gluma and Gluma/Scotchbond restorations showed a 14.3% and 7.4%, cumulative loss of retention respectively. No secondary caries was observed during the evaluation period.
Glass ionomer and resin‐based fissure sealants: a clinical study
Authors: MEJÀRE* INGEGERD , MJÖR IVAR A.
Published: October 2007

Abstract – The aim of this study was to compare the retention rate of a glass ionomer cement formulated for fissure sealing with two resin‐based sealants. 208 occlusal fissures of permanent molars and premolars were sealed with either Fuji III, Delton or Concise WS by four dentists. Clinical assessments and a replica scoring technique were used to register the performance of the sealants at baseline, after 6–12 months, and then yearly up to 5 yr. As judged clinically, 61% of the glass ionomer sealants were lost within 6–12 months and 84% after 30–36 months. Although total loss was recorded clinically for the majority of the glass ionomer sealants, some retained sealant was observed in the tooth replicas in 93%, of them. The clinical evaluation of the resin‐based sealants showed an average complete retention rate of 90% after 4.5–5 yr. The corresponding figure with the replica technique was 58%. Caries was recorded in 5% of the resin‐based and in none of the glass ionomer sealed surfaces.
Transmission electron microscope observations on enamel following silver methenamine staining
Authors: SÖGAARD‐PEDERSEN BO , MATTHIESSEN MARTIN EBBE
Published: October 2007

Abstract – Transmission electron microscope observations on porcine enamel and secretory ameloblasts showed that silver methenamine material was located inside secretory vesicles in secretory ameloblasts and along the enamel crystals inside immature enamel. It is concluded that silver methenamine is able to stain enamel proteins selectively inside these tissues.
Effect of plasma on composition of human enamel and cementum pellicle
Authors: KAJISA LINDA , PRAKOBPHOL AKRAPORN , SCHIÖDT MORTEN , FISHER SUSAN J.
Published: October 2007

Abstract – Slabs of human enamel and cementum were incubated with plasma alone or with various mixtures of plasma and saliva. Proteins and glycoproteins that adsorbed to the surface of the slabs in 0 to 60 min were labeled by lactoperoxidase‐catalyzed 125I‐iodination and by mild periodate oxidation followed by NaB3H4 reduction. The labeled components were separated by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and visualized by autoradiography or fluorography. From plasma alone, a 58 and a 66 kDa protein (probably albumin) were adsorbed to the enamel surface in relatively equal amounts, but no 125I‐labeled components were detected on the cementum surface in the absence of saliva. Adding 10% saliva to the incubation mixture promoted the adsorption of the 58 and 66 kDa components to cementum. In addition, another set of proteins, including components of 44, 47, 29, and 25 kDa, was adsorbed to both cementum and enamel in the presence of saliva. These six proteins were the major 125I‐labeled species in all of the pellicles formed from mixtures of plasma and saliva. The electrophoretic mobility of the major 120 and 140 kDa 3H‐labeled sialoglycoproteins adsorbed to both cementum and enamel was similar to that of the low‐molecular‐weight mucin of submandibular/sublingual saliva.
Dental cementum apposition as an indicator of age
Authors: SOLHEIM TORE
Published: October 2007

Abstract –The purposes of the present investigation were to examine various ways of measuring cementum thickness, to study its relationship with age, and to consider what contribution this factor might offer in methods for age estimation. The amount of dental cementum apposition was studied in 1000 teeth, excluding molars, from a Caucasian population. Cementum thickness was estimated according to the scoring methods suggested by Gustapsonand by Johanson. In addition, the width of the cementum was measured at the apex and also at approximately one third of the root length from the apex. Statistical analyses using the SPSS package in a Cyber computer indicated a symmetric left/right distribution of cementum thickness. The sum of the cementum thickness on vestibular and lingual surfaces, measured at one third of the root length from the apex, showed the strongest correlation with age (r = 0.40 to 0.65). A reduced rate of cementum apposition was observed in the elderly. Also, maxillary teeth had more cementum on the lingual than on the vestibular surfaces. A tendency was noted for less cementum to occur in women than in men and on teeth removed from deceased persons or extracted for pathologic reasons. Correlation coefficients indicated that, for at least some types of teeth, the cementum thickness might give a significant contribution to statistical methods of age assessment.
Application of a new mechanical properties microprobe to study hardness of eroded bovine enamel in vitro
Authors: MEURMAN J. H. , TORKKO H. , HIRVONEN J. , KOSKINEN J. , RYTÖMAA I.
Published: October 2007

Abstract – A mechanical properties microprobe technique was used to study bovine tooth specimens that had been immersed in 50 ml of either cola beverage or sports drink for 1 min, 5 min, and 15 min. A Vickers diamond was used to analyze the test and control surfaces at 7V input. This corresponds to a 100 g load of a conventional indentation microhardness apparatus which was used for comparison. The results showed good agreement between the conventional and the microprobe hardness analyses. Enamel softening was found to be significant after 5 min immersion in both acidic drinks, while 1 min immersion did not cause softening. This shows that shorter immersion times than previously used can be applied in dental erosion studies in vitro. Compared with the conventional indentation microhardness measurements, however, the microprobe technique did not offer any advantage, such as assessment of the microelastic properties of enamel, probably because the biologic tissue did not allow reliable data collection during the loading and unloading phases of the instrument.
Intraindividual variations in counts of mutans streptococci measured by “Strip mutans” method
Authors: ISMAIL EL‐NADEEF MAI AHMED , BRATTHALL DOUGLAS
Published: October 2007

Abstract— Intraindividual variations in the mutans streptococci measured by Strip mutans, in a 1‐day and a 5‐day period, as well as the effect of toothbrushing, were investigated. 30 subjects participated, and their levels of salivary mutans were estimated by a scale containing four steps. With the exception of three comparisons, time intervals of different lengths did not cause a deviation of more than one step. Comparisons made before and after toothbrushing yielded the same score in 22 cases, whereas two subjects showed a discrepancy of two steps. Clearly, in a short‐term perspective, variations can certainly be found, but more pronounced discrepancies are rare.
Craniofacial growth in bone marrow transplant recipients treated with growth hormone after total body irradiation
Authors: DAHLLÖF GÖRAN , FORSBERG CARL‐MAGNUS , NÄSMAN MARGARETA , MATTSSON TORSTEN , MODÉER THOMAS , BORGSTRÖM BIRGIT , BOLME PER , RINGDÉN OLLE
Published: October 2007

Abstract— The effect of growth hormone (GH) treatment on craniofacial development was studied in five children exhibiting growth retardation following bone marrow transplantation. Linear and angular measurements were made on lateral radiographic cephalograms taken prior to the start of GH treatment and after an average treatment time of 1.2 yr. The results showed that the mean growth increments of mandibular length in the GH treated children, exceeded the corresponding values of the control group by 150% during the period of investigation. It is suggested that this dimensional increase in the patients was due to GH stimulation on the chondral growth process in the mandibular condyles.
Transmission electron microscopic appearance of dentin matrix in type II dentin dysplasia
Authors: WALTIMO JANNA , RANTA HELENA , LUKINMAA PIRJO‐LIISA
Published: October 2007

Abstract— Dentin matrix of demineralized primary and permanent teeth with type II dentin dysplasia was studied by transmission electron microscopy. The coronal dentin of a maxillary third molar exhibited a normal structure. In the radicular dentin, tubules were few in number; the major part of the dentin was composed of thick, curvy bundles of cross‐striated collagen fibers. In the most aberrant areas of the radicular dentin, coarse collagen fibers measuring up to 140 nm in thickness were observed. The dentin of the primary tooth showed a similar, but somewhat less irregular, structure.
Retrospective study of children with hypophosphatasia with reference to dental changes
Authors: LUNDGREN TED , WESTPHAL OTTO , BOLME PER , MODÉER THOMAS , NORÉN JÖRGEN G.
Published: October 2007

Abstract— In the present retrospective study different dental and medical parameters have been analyzed in 17 Swedish children with established hypophosphatasia (HP). It was demonstrated that the basis for the establishment of the diagnosis varied among different dentists and physicians, and that the diagnostic parameters studied among the children varied. The most reliable parameters for HP included raised levels of phosphoethanolamine in urine, and clinical and radiologic findings associated with the legs. These findings were found among the children more often than lowered values of alkaline phosphatase in serum. Histologic analysis of an extracted tooth made a valuable diagnostic complement. It is concluded that a better diagnostic uniformity is recommended. In a well functioning collaboration with well defined tasks, both dentists and physicians can contribute to a reliable diagnosis.
Combined inhibitory effect of lactoferrin and lactoperoxidase system on the viability of Streptococcus mutans, serotype c
Authors: SOUKKA TERO , LUMIKARI MARIANNE , TENOVUO JORMA
Published: October 2007

Abstract— We have studied the effects of iron‐free lactoferrin (apo LF) and lactoperoxidase system (lactoperoxidase, LP/SCN‐/H2O2), separately and together, on the viability of Streptococcus mutans (serotype c) in vitro. The bacteria were incubated in buffered KCl (pH 5.5) with and without the above components which were used at concentrations normally present in human saliva. Both apo LF and LP‐system had a bactericidal effect against S. mutans at low pH. Together they showed an additive, but not a synergistic, antibacterial effect against S. mutans. Apo LF enhanced the LP enzyme activity but decreased the yield of the antimicrobial component, hypothiocyanite (HOSCN/OSCN‐), when incorporated into the reaction mixtures. This decrease, which was most pronounced at low pH, was due to an LP‐independent reaction between apo LF and HOSCN/OSCN‐. Our study indicates that the LP‐system and apo LF can be combined to combat oral S. mutans.
Histoquantitative study of inflamed tongue mucosa
Authors: JÄRVINEN JAANA , KULLAA‐MIKKONEN ARJA , PESONEN ERKKI
Published: October 2007

Abstract— A quantitative, semiautomatic analysis of hislologic features of the specific inflammatory changes occurring on the dorsum of human tongue was made for 37 tongues. Well‐documented hislologic differences belween clinically normal appearing tongue (control), atrophic, geographic and fissured tongue were shown quantitatively. The epithelium of atrophic tongue was thinner compared to the controls. Reduction of the thickness was due to the shortened or totally missing rete pegs. Epithelium of geographic and fissured longue showed irregular rete pegs. In fissured tongue heavy inflammation seemed to shorten the rete pegs. In atrophic tongue the connective tissue was thicker compared to the controls. This could be due to mild, chronic inflammation causing loose connective tissue described in atrophic tongue. Muscle cells of geographic tongue appeared lo be as in the controls, whereas in atrophic and fissured tongue the uppermost muscle cells were small and separated compared to the controls.
Light and transmission‐electron microscopy study of enamel organ cells in germectomized human third mandibular molars
Authors: EKSTRAND KIM RUD , BJÖRNLAND TORE , THYLSTRUP ANDERS
Published: October 2007

Abstract— Using nine serially sectioned germectomized mandibular third molars it was possible to examine light microscopical (LM) and transmission‐electron microscopical (TEM) features of maturing human enamel organ cells. The degree of enamel mineralization was estimated by quantitative imbibition studies in polarized light. It was possible to distinguish between three progressive stages of enamel mineralization. The most advanced stage was characterized by external enamel porosity. In the least advanced stages the enamel porosity appeared more extensive beneath a less porous surface layer. Ruffle‐ and smooth‐ended ameloblasts were identified corresponding to the maturing enamel. Smooth‐ended ameloblasts were the most frequently observed. However, no preferences for one of the two cell types could be observed in relation to the different stages of enamel mineralization. The maturing human enamel organ cells broadly revealed the same characteristics with respect to morphology features, intracellular organization, and junctional complexes as described in the maturation zone of the rat incisor enamel organ. Our findings therefore add to the view that the basic pattern of amelogenesis is identical in human and rat incisor enamel.
Effect of whole saliva on the rheologic behavior of extracellular water‐soluble glucan produced by Streptococcus mutans
Authors: RUNDEGREN JAN , ARNEBRANT THOMAS , LINDAHL LENNART
Published: October 2007

Abstract— The viscosity of mixtures of Streptococcus mutans water‐soluble glucan and stimulated whole saliva or buffer was measured at pH 5, 6, 7, and 8. The viscosity was measured as a function of shear rate in the range 15 s‐1‐230 s‐1. Though the centrifuged saliva had a viscosity close to that of water it increased the viscosity of the glucan up to 65% at pH 6 and 55% at pH 7 and at a shear rate of 20 s‐1, indicating an interaction between saliva components and glucan that could be an important part of the cohesive forces of plaque matrix. The interaction between saliva and glucan was less pronounced at pH 5 and 8, which indicates a charge‐dependent interaction. The viscosity increase at pH 6 and 7 was higher at low than at high shear rates, suggesting a higher contribution to plaque stability when weak as opposed to high mechanical forces are exerted on the plaque.
Interactions between and within Streptococcus mutans and Streptococcus sobrinus isolated from humans harboring both species
Authors: LINDQUIST BIRGITTA , EMILSON CLAES‐GÖRAN
Published: October 2007

Abstract— The prevalence of Streptococcus mutans and Streptococcus sobrinus was examined in plaque samples from small discrete areas of the buccal tooth surfaces of seven subjects. Strains of S. mutans and S. sobrinus were isolated and tested for bacteriocin‐mediated interactions between and within the two species, using the stab inoculation technique. S. mutans and S. sobrinus did not colonize each tooth surface uniformly and, in plaque from small discrete sites, S. mutans and S. sobrinus were either undetected or present in different interspecies proportions. Within the same subject, there were no bacteriocin‐mediated interactions between strains of the same mutans species and no difference in bacteriocin activity was found between the strains of S. mutans and S. sobrinus from different sites. When bacteriocin interactions were tested between isolated strains from all seven subjects a somewhat higher inhibition ability was found for producer strains isolated from plaque compared with those isolated from saliva. S. mutans appeared to be more bacteriocinogenic than S. sobrinus. Replacing the glucose in the medium with sucrose enhanced the bacteriocin activity of S. mutans towards other S. mutans strains but reduced the inhibitory interaction towards strains of S. sobrinus.
Interference of oral hygiene products with an adhesion‐based assay of salivary mutans streptococci
Authors: SÖDERLING EVA , KETOLA TANJA , PARVIAINEN TAPIO
Published: October 2007

Abstract – The effect of several oral hygiene products on an adhesion‐based assay for salivary mutans streptococci (Dentocult‐SM Strip Mutans) was studied in three women. The mutans streptococci levels were recorded for up to 24 h after a 1‐min rinse with the product. The chlorhexidine (0.05%) and stanno‐amine fluoride solutions (corresponding 0.025% F) interfered selectively with the adhesion‐based assay. No such effect was observed for a polyvidoneiodine solution (10 μg/ml) or two toothpastes containing either sodium lauryl sulfate or amine fluorides. The results indicate that antimicrobial agents showing retention in the oral cavity may interfere for several hours after their use with adhesion‐based assays of salivary mutans streptococci.