bluuebunny/crossref_metadata_2025 huggingface dataset:
Three‐year study of the effect of fluoride varnish (Duraphat) on proximal caries progression in teenagers
Authors: MODÉER THOMAS , TWETMAN SVANTE , BERGSTRAND FREDRIK
Published: October 2007

Abstract – The effect of sodium fluoride varnish (Duraphat) applications on proximal caries progression was studied during a 3‐yr period in 87 teenagers and compared to a control group (n= 107). In the fluoride varnish group the children were treated with fluoride varnish every third month during the experimental period. Caries lesions on the mesial surfaces of first premolars to the mesial surfaces of second molars were recorded annually on radiographs and an individual progression value was calculated. The study showed that topical application of fluoride varnish every third month significantly (p<0.05) reduced the progression of proximal caries lesions in premolars and molars. The most obvious reduction of caries progression was observed among children who developed between two and eight new proximal lesions during the test period. In the children with the highest caries activity (> nine new proximal lesions) Duraphat treatments did not significantly reduce proximal caries progression in premolars and molars.
Stimulated salivary flow rate, pH and lactobacillus and yeast concentrations in persons with different types of dentition
Authors: PARVINEN TUIJA
Published: October 2007

Abstract – The flow rate of stimulated whole saliva did not differ significantly in relation to dentition in men and premenopausal women in an unmedicated population. In the postmenopausal women the flow rate was lower in full denture wearers and in those having a highly reduced number of occluding pairs of teeth. Full denture wearers had salivary yeasts and lactobacilli more often and with higher counts than fully dentate persons, a group which in any case showed a difference in the yeast distribution between the sexes.
Dental features in congenital persistent renal tubular acidosis of proximal type
Authors: KOPPANG HANNA STRÖMME , STENE TORBJÖRN , SOLHEIM TORE , LARHEIM TORE A. , WINSNES ARNT , MONN EIRIK , STOKKE ODDVAR
Published: October 2007

Abstract –

The dental features in a hitherto unknown type of renal tubular acidosis (capillary blood pH 7.07–7.15) of proximal type are reported. The patient presented agenesis of three second premolars, delayed development and eruption of permanent teeth, delayed shedding of the primary dentition and severe enamel hypoplasia of the permanent teeth, Apart from exceptionally thin enamel, histologic, fluorescent and polarization microscopic and microradiographic investigation of three primary teeth did not reveal unusual findings. The changes are most probably due to a generalized, acidosis‐induced defect in several highly differentiated ectodermal tissues.
Extraction of enamel proteins
Authors: MOE DENNIS , SALLING ELISABETH , KIRKEBY SVEND
Published: October 2007

Abstract –

Two multi‐step extraction procedures were used to isolate matrix proteins from fetal bovine enamel. Using SDS‐PAGE and gel isoelectric focusing it was concluded that extraction procedures influence the number of protein bands in the gel, their pI, apparent molecular weight and staining intensity.
Inflammatory cell infiltrate in labial salivary glands of patients with rheumatoid arthritis with special emphasis on tissue mast cells
Authors: SYRjÄNEN STINA M. , SYRJÄNEN KARI J.
Published: October 2007

Abstract –

The labial salivary glands of 81 patients with rheumatoid arthritis (RA) and those of 45 control (CO) patients were biopsied. Mast cell counts were compared with the number of other inflammatory cells (B‐ and T‐lymphocytes and mononuclear phagocytes, stained with acid‐α‐naphthyl acetate esterase technique (ANAE) and to fatty change and fibrosis. Mast cells were directly related to the amount of fibrosis and fatty change in both series, supporting the recent theory that these changes are age‐related phenomena and not caused by RA per se. M ast cell counts increased slightly with increasing inflammatory cell infiltration, but no correlation could be Found between mast cell counts and B or T cells. Mononuclear phagocyte system (MPS) cells were fewer in the RA group than in CO patients, possibly suggesting an impaired phagocytizing capacity In their salivary glands. In many respects the results are consistem with the known function of tissue mast cells. There role in the labial salivary glands is dicussed in the light of current immunopathologic concepts of RA and lesions associated with it, i.e. Sjögren's syndrome
Incisor and jaw relationship in 27 persons with osteogenesis imperfecta
Authors: STENVIK ARILD , LARHEIM TORE A. , STORHAUG KARI
Published: October 2007

Abstract –

The incisor relation and craniofacial morphology, as evaluated from lateral cephalograms, were studied in 14 women and 13 men with osteogenesis imperfecta. A negative overjet was found in one woman and five men, and for the total material a mesial basal jaw relationship was observed. Data for both women and men indicated that skeletal discrepancies had been partially compensated for by the incisor inclination. Probably, persons with osteogenesis imperfecta may be regarded as a potential high‐risk group for development of malocclusion.
Regression analysis of electromyographic activity of masticatory muscles versus bite force
Authors: HAGBERG CATHARINA , AGERBERG GÖRAN , HAGBERG MATS
Published: October 2007

Abstract –

Electromyographic (EMG) activity of the superficial masseter and the anterior temporal muscles versus the bite force was studied in 10 young women. They were fully dentate and had no dysfunction of the stomatognathic system. The descending part of the trapezius muscle was also chosen for EMG registration. The average bite force between the first molars was 396 N (Newton). Steeper slopes for the EMG versus force regression curve at high contraction levels than at low contraction levels for the superficial masseter muscle may indicate that this muscle has a recruitment pattern that differs from that of the anterior temporal muscle. In the case of the anterior temporal muscle there was no difference between the slopes for the EMG‐force regression at low and high contraction levels. There was significantly increased activity in the descending part of the trapezius muscle mainly during high bite force levels in half the subjects.
Electron probe study of coronal dentin in red deer
Authors: HALS EINAR , TÖTDAL BARD
Published: October 2007

Abstract –

A topographic description of the concentration profiles of Ca, P, Mg, Zn, F, S and K in coronal dentin of red deer is given. The concentrations reported should be regarded as serniquantitative values. An area along the mesiodistal axis of the crowns showed lower concentrations of Ca and P and higher concentrations of Mg than the surrounding bulk of dentin. The inner dentin revealed downward slopes of the Ca, P and Mg profiles toward the pulpal cavity, whereas the Zn, F and usually also the S profiles showed elevations. Incidental findings were elevations of S and K profiles near the worn incisal edges. The walls of giant tubules, which are frequent in red deer dentin, showed in many cases modest elevations of the Ga, P, Mg and Zn profiles. The lumina of these tubules revealed in a few instances elevation of the S profiles.
Ultrastructure of lingual enamel epithelium in rabbit permanent incisors
Authors: GREVSTAD HANS J. , SELVIG KNUT A.
Published: October 2007

Abstract –

The recent observation thai the lingual surface of the permanent rabbit incisor, in contrast to the rodent incisor, is covered with enamel near the initially formed tip, initiated a histologic study of the enamel epithelium in this region. Tooth buds from fetal New Zealand white rabbits aged 27 and 30 days in utero were processed for transmission electron microscopy. Examination of longitudinal and cross‐sections revealed a transition of secretory ameloblasts to postsecretory amelobasts on the facial aspect of the enamel organ. Incisally. the facial ameloblast layer was continuous with postsecretory ameloblasts on the lingual aspect. More apically on the lingual surface, a gradual transition between postsecretory and reduced ameloblasts occurred. This study shows that by day 27 in utero., the ameloblasts on the lingua] aspect of the tooth are in the postsecretory and degenerative stages and that, by day 30, the enamel epithelium lingually has been replaced by cementum on the prismatic enamel and by connective tissue.
Activity of γ‐glutamyl transferase in developing teeth of the rat
Authors: AHLUND‐LTNDQVIST CATHARINA , LINDSKOG SVEN
Published: October 2007

Abstract –

γ‐Glutarnyl transferase activity was studied with an enzyme histochemical technique in rat molar teeth at different stages of development, The odontoblasts showed an increasing activity during formation of the crown. The secretory ameloblasts did not show any activity, while activity was intense in the postsecretory ameloblasts. This activity was confined to the apical part of the cell. In the reduced ameloblasts at the enamel free cusp tips a similar activity was noted. Since γ‐glutamyl transferase has been shown to be involved in endocytosis and transport of amino acids, the localization of the enzyme in developing teeth suggests an active uptake of amino acids from the enamel matrix by the ameloblasts during enamel maturation.
Snuff‐induced lesions in Finnish recruits
Authors: JUNGELL PETER , MALMSTRÖM MARIA
Published: October 2007

Abstract –

Snuff‐induced lesions from 21 snuff users were studied clinically, histologically and by electron microscopy. Clinically most lesions appeared coarsely wrinkled, grayish white and slightly elevated. All lesions were found in the upper vestibular area. Histologically, epithelial thickening, acanthosis, vacuolation of surface cells and a slight subepithelial inflammatory reaction were seen. The electron microscopic findings revealed an intact basement lamina, increased tonofilament concentration moving up towards the surface of the epithelium, widening of intercellular spaces in the spinous cell layer and partial keratinization of surface cells. The salivary flow of resting saliva showed a slightly significant increase compared to controls. That of stimulated saliva was not significantly increased among snuff users.
Dentin‐polymer bond mediated by glutaraldehyde/HEMA
Authors: MUNKSGAARD ERIK CHRISTIAN , ASMUSSEN ERIK
Published: October 2007

Abstract –

A restorative resin was bonded to EDTA‐treated dentin by means of a mixture of glutaraldehyde and HEMA. The bond exhibited a tensile strength of 17.5 ± 1.0 MPa (mean ± SEM) and was unaffected by water storage at 37°C for up to 6 months. The glutaraldehyde/ HEMA mixture was found to be most effective when the pH was between 2 and 5; an application time of 10 s was found to be sufficient for the glutaraldehyde/HEMA mixture as well as for the EDTA‐solution.
Fluoride retention in clean and plaque‐covered demineralized enamel in vivo after application of monofluorophosphate
Authors: ÖGAARD BJÖRN , GAFFAR ABDUL , BAHL MAHINDER K. , RÖLLA GUNNAR , HELGELAND KRISTEN
Published: October 2007

Abstract –

The retention of fluoride in clean and plaquc‐covcred demineralized enamel in vivo was measured 1 wk after a single application of a MFP solution with low or high content of free fluoride. Demineralization of the enamel was induced in vivo during a 4‐wk period prior to application of fluoride by applying orthodontic bands on a pair of premolars scheduled for extraction of orthodontic reasons. The band from one tooth of each pair was then removed and the tooth cleaned (clean enamel lesion). The band on the contralateral tooth (plaque‐covered enamel lesion) was left in place. The MFP solutions were applied and the teeth extracted after one more week. The chemical form of fluorine in the lesions was analyzed by conventional acid etching of the enamel combined with KOH dissolution and by a nondestructive surface analysis using ESCA to detect intact monofluorophosphate ions. The ESCA measurements showed that MFP was only present in the clean enamel lesions, indicating complete hydrolysis by dental plaque. Alkali soluble fluoride could be extracted from both plaque‐covered and clean enamel lesions. Conflicting results regarding the amount of fluoride uptake in the lesions were obtained with the acid etching and the ESCA technique. It was thus not clearly established whether plaque enhanced fluoride uptake in carious lesions after MFP application.
Evaluation of rat incisor mesenchymal cells in bleomycin injected animals fixed by immersion or perfusion
Authors: DAHL JON EINAR , KJAERHEIM ASMUND
Published: October 2007

Abstract –

Bleomycin was administered to four groups of rats in a single intravenous injection of 25 mg/kg, 50 mg/kg, 75 mg/kg and 100 mg/kg, respectively. The animals were killed by perfusion or by decapitation followed by immersion fixation at 24 h and 5 days after injection. Sections were made of maxillary incisors and evaluated by light microscopy. Bleomycin produced a transitory arrest of dividing cells resulting in an apparent synchronization of the cell population. Necrotic cells were found within the basal pulp and the preodontoblasts at 1 day observation time. After 5 days a dentinal lesion was observed at the two highest dose levels and the necrotic areas were filled in by proliferating adjacent cells. A better quality of fixation, especially of cells surrounded by dentin, was observed in perfusion fixed animals but the fixation procedure did not influence the alterations found in experimental animals.
Pattern of distribution of T lymphocytes, Langerhans cells and HLA‐DR bearing cells in normal human oral mucosa
Authors: REIBEL JESPER , DABELSTEEN ERIK , KENRAD BIRGIT , BUSCHARD KARSTEN
Published: October 2007

Abstract –

The tissue distribution of helper/inducer and suppressor/cytotoxic T cells, Langerhans cells (LC) and HLA‐DR bearing cells was determined in normal oral mucosa by use of monoclonal antibodies OKT4, OKT8, OK.T6 and OKIal, respectively. OKT4+ and OKT8+ cells were invariably present in normal oral epithelium and in the lamina propria. OKT8+ cells were consistently seen inside the basal cell layer of the epithelium. The distribution of LC in oral epithelium showed regional variation. In palatal epithelium LC were evenly distributed in the basal half of the epithelium, whereas in buccal mucosa the highest concentration of LC was seen in the epithelium overlying the tips of connective tissue papillae. OKIal stained dendritic cells in the epithelium and plump cells with small dendritic processes in the connective tissue. Some of the latter were located close to the basal cells of the epithelium. The consistent relationship between immunocompetent cells and the epithelium of the oral mucosa suggests the presence of a local immunologic defence barrier in the oral mucosa.
Comparative antibacterial effectiveness of seven hand antiseptics
Authors: MYKLEBUST STALE
Published: October 2007

Abstract –

Seven hand antiseptics (alcohol‐, iodophor‐ and chlorhcxidine preparations) were compared for antibacterial effectiveness using finger‐print contact sampling on blood agar in duplicate series with 18 students as test persons. Bacterial samples were obtained before and after handwashing (with unmedicated liquid soap) as well as after hand disinfection. Hibiscrub was tested without prewashing. The antiseptics were rubbed into the skin and the hands left uncontaminated for 2 min before sampling. Due to results showing unexpectedly low antibac‐terial effectiveness of 70% (v/v) ethanol, a series of supplementary experiments with ethanol (70% (v/v) and 80% (v/v)) and isopropanol (60% (v/v)) were performed with 10 laboratory staff‐members. These experiments confirmed the previously demonstrated weak antibacterial effect of 70% (v/v) ethanol on the normal hand flora. Alcoholic chlorhexidine solutions and Hibiscrub were the only preparations that gave significant, mean reductions (97.9‐99.9% and 80.3‐93.4%, respectively) in the number of colony forming units. According to the present study, these are the only test preparations that can be recommended for presurgical hand disinfection, and when hand disinfection is needed in general dental practice.
Tetracycline‐impregnated enamel and dentin: duration of antimicrobial capacity
Authors: BJORVATN KJELL , SKAUG NILS , SELVIG KNUT A.
Published: October 2007

Abstract – The present study was done in order to examine the durability of the tetracycline‐induced antimicrobial capacity, and also to assess the reproducibility of the bacterial growth‐inhibitory assay used. Standardized enamel and dentin specimens were impregnated in aqueous solutions of tetracycline HCl, oxytetracycline HCl or doxycyclinc HCl, rinsed in water, and stored dry for 200 days. Another series of specimens was impregnated in solutions of doxycychne HCl and then rinsed in tap water for varying periods up to 35 days. In addition, drug‐impregnated specimens were used for reproducibility tests without storage or prolonged rinsing. Impregnated specimens were tested for antimicrobial capacity on agar plates seeded with S. sanguis. After 24 h aerobic incubation in 10% CO2 atmosphere, the plates were inspected and the diameter of the bacterial growth inhibition zones measured. The drug‐impregnated enamel and dentin specimens consistently demonstrated growth‐inhibitory capacity. The results of the reproducibility tests showed moderate intrasample and day‐to‐day variation. Two hundred days of dry storage or 35 days soaking in water reduced, but did not eliminate, the bacterial growth‐inhibitory capacity of the impregnated dental specimens. The results show that a short‐term exposure of dental hard tissues to tetracyclines may result in a long‐lasting antibacterial capacity.
Pulpal blood flow in immature permanent dog teeth after replantation
Authors: HEYERAAS KARIN J. , MYKING ANNE M.
Published: October 2007

Abstract – Pulpal blood flow (PBF) was measured by H2‐gas clearance in 35 replanted (incisors and premolars) and 22 contralateral control dog teeth. The PBF measurements were taken 6, 10, 16, 21 and 28 days after replantation. At 6, 10 and 16 days after replantation there was no measurable blood flow in the coronal pulp of either replanted incisors or premolars. 21 days after replantation a considerable reduction in PBF was measured in all replanted teeth. On average, PBF was reduced to about one fifth of PBF in the simultaneously measured contralateral controls. Four weeks after replantation, a more than threefold increase in PBF was measured in premolars with two roots, while PBF in premolars with one root and incisors was consistently reduced to an average of 40% of the controls. The vascular pattern of the teeth 4 wk after replantation was identified with perfusion of silicon rubber. The measurements suggest that replanted multirooted teeth revascularize more easily than single‐rooted teeth, and that pulpal repair is restored by a gradual replacement and proliferation of new tissue.
Studies on the whole‐body distribution of 14C‐trithioparamethoxyphenylpropene in mice
Authors: ISACSSON GÖRAN , SINGER PETER
Published: October 2007

Abstract – The study was undertaken to map the whole body distribution of trithioparatnethoxyphenylpropene, TPMPP, a substance which is believed to stimulate salivaty secretion. Two series of male and pregtiant female mice were given 4.3 μCi 14C‐TPMPP by gastric intubation. The animals were sacrificed at various intervals, embedded in CMC and frozen. Sections were taken from all levels and wholebody autoradiography performed. Four hours after administration the isotope was located in the intestines, liver, gall bladder, kidney and urinary bladder. High concentrations of the isotope persisted for 12 h with the exception of the kidney which showed decreasing concentrations after 4 h. The isotope was not found in the fetus or placenta. 24 h after administration no activity could be detected in any of the above mentioned organs. If TPMPP plays a role in salivary secretion this must be secondary as it was not found in the salivary glands, or nerve structures.
Two‐year assessment of anterior resin restorations inserted with two acid‐etch restorative procedures
Authors: QVIST VIBEKE , STRÖM CARSTEN , THYLSTRUP ANDERS
Published: October 2007

Abstract Fifty‐two pairs of Class III restorations in a microfilled resin Silar were inserted in acid‐etched cavities. A bevel preparation was performed along the margin of one cavity (A) whereas the other cavity was treated with the surface‐active comonomer NPG‐GMA before filling (B). After finishing of the restorations, the surface of the type B filling was re‐etched and covered with a layer of non‐composite, low‐viscous resin. Following a 2‐yr observation period 65 restorations were classified as “good”, 33 were “adequate” and 4 were “unsatisfactory” or were replaced during the study period. The only significant difference between type A and type B restorations was marginal discolorations which most frequently were observed along the beveled type A restorations. The occurrence of such failures was increased by marginal deficiencies and occlusion/articulation on the restorations.
Electrochemical potentials of amalgam restorations in vivo
Authors: NILNER KRISTER , HOLLAND ROY I.
Published: October 2007

Abstract The potentials of 407 amalgam restorations have been determined in vivo. The measurements were performed with very high impedance equipment, and relative to a Ag/AgCl reference electrode. The readings varied from — 23 mV to —595 mV, with 90% of the readings confined to within — 127 mV to —431 mV and a mean value of —226.1 mV. Of the restorations, 394 were measured twice, and no significant difference could be found between the first and the second reading. During the study, eight new restorations were inserted. Their potentials varied from —180 mV to —565 mV, with a mean of —339.4 mV, which was significantly lower than that of the older restorations.
Effect of ethanol and NPG‐GMA on replica patterns on composite restorations performed in vivo in acid‐etched cavities
Authors: QVIST VIBEKE , QVIST JÖRGEN
Published: October 2007

Abstract 29 experimental Class V restorations using a chemically cured composite resin were inserted in human third molars in cavities which after acid‐etching had been treated with absolute ethanol. After extraction and demineralization of the teeth, the fillings were examined in SEM concerning their enamel and dentin replica patterns on the inner cavity‐faced surface. The SEM findings were compared with previous findings concerning the replica patterns on fillings from acid‐etched cavities and from cavities which after acid‐etching had been treated with an ethanol solution of the surface active comonomer N‐phenylglycine‐glycidyl methacrylate (NPG‐GMA). It was found that cavity treatment with absolute ethanol further improved the increased enamel replica patterns obtained with the NPG‐GMA/ethanol comonomer solution while only the NPG‐GMA/ethanol treatment improved the dentin replica patterns. Based on these results the effect of each of the two main components in the comonomer solution on replica patterns on resin restorations could be disclosed.
Effect of combining dentin bonding agents
Authors: MUNKSGAARD ERIK CHRISTIAN , ITOH KAZUO , ASMUSSEN ERIK , JÖRGENSEN KNUD DREYER
Published: October 2007

Abstract The wall‐to‐wall polymerization contraction of a light‐cured composite was measured in cylindrical dentin cavities treated with the bonding agents: Scotchbond, Clearfil Bond, Gluma/Scotchbond, Gluma/Silux Enamel Bond or Gluma/Clearfil Bond. Marginal gaps were prevented in 29 out of 30 cases when Gluma was used in combination with Clearfil Bond. This combination mediates a mean bond strength between composite and dentin of 20 MPa.
Immunoglobulin G in cystic lesions of rat enamel organ following fluoride intoxication
Authors: NORDLUND ANITA LANGE , LINDSKOG SVEN
Published: October 2007

Abstract –

Fluoride given as a high single dose to young rats with developing molars has earlier been shown to cause subameloblastic cysts with disorganized ameloblasts in the cystic wall and an irregular mineralization pattern of the underlying enamel. In the present study irnmunohist‐ochemistry has been employed to determine if an increased permeability of the enamel organ occurred at the areas of cell disturbances. For this purpose 5‐day‐old rats were injected with 60 mg sodium fluoride per kg body weight. They were decapitated after 24 h, the maxilla prepared histologically and paraffin sections incubated for the demonstration of IgG according to the avidin‐biotin‐peroxidase complex method. Staining for IgG was present in the cystic lumina and in areas of disorganized ameloblasts. No reaction was observed in areas of unaffected ameloblasts. It was suggested that the fluoride‐induced cell injury increased the permeability of the ameloblastic cell layer. Diffusion of IgG and most likely other substances as well, through the ameloblastic layer may have contributed to cyst formation and to the irregular mineral deposits that have been found in the ameloblastic layer and at the enamel surface.
Clinical and radiographic appearance of proximal carious lesions at the time of operative treatment in young permanent teeth
Authors: MEJÀRE INGEGERD , MALMGREN BARBRO
Published: October 2007

Abstract –

Clinical tissue changes were recorded during restorative treatment of proximal carious lesions of young premolars and molars. 60 proximal surfaces with radiolucencies in the inner half of the enamel or the outer half of the dentin were treated. The extent and character of the tissue changes were documented with photographs taken during drilling and evaluated after magnification. The maximum extent for each lesion was correlated to the extent of the radiographically observed lesion. The results showed that 70% of the restored surfaces were associated with a breakdown of the enamel surface. When the radiolucency did not extend deeper than into the inner half of the enamel, cavities were found in 61%; for lesions with a radiolucency extending into the outer half of the dentin the percentage was 78%. In the majority of cases the cavity was limited to the enamel. In all cases discoloration was observed in the enamel. The dentin was soft and discolored in 83%. Severe damage of tooth substance was found in 12% of the teeth.
An in vivo method for microhardness measurements on human teeth
Authors: FOSSE GISLE , ROSENGREN BENGT , SKAALE SIREN , LEKNES KNUT , WULFF LENA
Published: October 2007

Abstract –

A non‐destructive, in vivo method of measuring the enamel hardness directly on patients is described. Normal values on 39 students arc given and compared with those of five patients, one of whom suffered from abnormal oral acid concentration, and the others from the effects of various degrees of hyposialosis caused by radiologic treatment of tumors in head and neck. The difference between the two groups was significant below the 0.1% level. It was suggested that the method may be used to test the degree of salivary gland inactivation after radiologic treatment and the efficiency of different saliva substitutes used to alleviate the effects of hyposialosis.
Staining patterns of rodent squamous epithelia by monoclonal anti‐keratin antibodies
Authors: REIBEL JESPER , DABELSTEEN ERIK
Published: October 2007

Abstract –

Anti‐keratin staining patterns were examined by immunofluorescence in the epidermis, oral mucosa and forestomach of rats and mice by monoclonal antibodies AE1 and AE2. In contrast to human tissues enzymatic pretreatment of sections was necessary even when freshfrozen tissue was used, suggesting masking of the antigens in vivo. AE1 stained the cytoplasm of spinous cells in most epithelia, whereas basal cell staining varied. AE2 showed suprabasal cytoplasmic staining in epidermis, forestomach and palate, whereas the other epithelia were stained only in keratohyalin granules and membranes of cornified cells. In some epithelia a small number of irregularly distributed basal cells stained positive with AE2, indicating heterogeneity in the basal cell compartment. Thus, the anti‐keratin staining pallern varies both regionally and, as earlier shown in human epithelium, with the stage of maturation of cells within a given epithelium. The present study provides a basis for further studies of epithelial differentiation during normal and pathologic development.
In vitro activation of amphibian dermal melanocytes by nicotine
Authors: HEDIN C. ANDERS , LARSSON ÅKE
Published: October 2007

Abstract –

Epidemiologic investigations have shown that nicotine could be a factor causing oral melanin pigmentation in man. Nicotine was therefore tested on amphibian skin melanocytes. Cell reactions were registered by spectrophotometry, in vitro light microscopy, photomicrography and light and electron microscopy. It was found that dermal melanocytes in the toad Bufo bufo and the frog Rana arvalis were activated by nicotine and that this activation was not mediated via β‐adrenergic receptors in melanocytes.
Gingival and alveolar bone reaction to marginal fit of subgingival crown margins
Authors: SORENSEN S. E. , LARSEN I. BIRK , JÖRGENSEN K. DREYER
Published: October 2007

Abstract — Interproximal subgingival marginal discrepancies of full coverage restorations were compared with adjacent crevicular fluid flow and percentage radiographic periodontal bone loss. A total of 88 patients with 116 premolar crowns were evaluated. Patients were selected at random from student treatment records, Institute of Dental Prosthetics, Royal Dental College, Copenhagen, Denmark. Crevicular fluid collected on filter paper strips from the interproximal area was stained with 0.2% ninhydrin solution and the length of the area measured. Marginal fit was determined by measuring the marginal excess or deficit recorded in a polyether impression. The amount of bone around each crowned tooth was measured on five times magnified prints of radiographs. Percentage bone loss was calculated by dividing the distance from the alveolar crest to the most coronal level at which the periodontal space retained its normal width by the distance from the alveolar crest to the root apex. Correlating marginal fit with crevicular fluid within gingival index scores showed r = 0.32 (G.I.l) and r = 0.42 (G.I.2). Fit vs percentage bone loss showed r=0.68 and r = 0.59, respectively (P<0.001). Differentiation was further made within the 0.0–0.2 mm range discrepancy by categorizing the data in four groups. Comparing fit relative to crevicular fluid and bone loss, most of these groups were significantly different when analyzed statistically using the Mann‐Whitney U‐Test. Small defects <0.050 mm were associated with significantly less fluid flow and bone loss than defects exceeding this value.
Surface discoloration of restorative resins in relation to surface softening and oral hygiene
Authors: ASMUSSEN ERIK , HANSEN ERIK KEITH
Published: October 2007

Abstract — Restorative resins are susceptible to softening caused by organic acids produced in plaque. Consequently, plaque‐covered resin restorations may be liable to pronounced surface staining. In the clinical part of the study a relationship between surface staining and local oral hygiene was demonstrated. This may be explained by the results from the laboratory part of the study, in which a relationship between surface staining and softening was found.
Restraining factors affecting setting expansion of phosphate‐bonded investments
Authors: JÖRGENSEN KNUD DREYER , OKAMOTO AKIRA
Published: October 2007

Abstract — The effects of several factors on the setting expansion of a phosphate‐bonded investment used in a steel casting ring were studied. The results show that the setting expansion under the conditions analyzed can be characterized only as a most unreliable means to partly compensate for the solid thermal contraction of casting alloys in a precision‐requiring technique.
Clinical and scanning electron microscopic study of surface changes of incipient caries lesions after debonding
Authors: ÅRTUN JON , THYLSTRUP ANDERS
Published: October 2007

Abstract — The surface features of incipient caries lesions around bonded orthodontic brackets were assessed longitudinally. In standardized periods after debonding and clean‐up, color slides were made and silicone impressions were taken of two maxillary incisors on each of six adolescent patients. These teeth were characterized by varying degrees, of macroscopically visible demineralized white areas around the bonded brackets. The color slides were studied in a dark room. The positive surface replicas were studied in SEM. At the time of debonding heavy accumulations of dental plaque were observed in all areas corresponding to the white, demineralized areas. During the experimental period there was a reduction in these plaque deposits. The appearance of the lesions changed from chalky‐white at the time of debonding to a more diffuse opacity, particularly in the peripheral parts of the lesion. Examination of the surface replicas in the SEM revealed a general tendency toward leveling of the surface of the lesion indicating a loss of porous tissue. At higher magnification the lesions showed signs of wear. Four teeth were presented to illustrate typical examples of the time‐related changes at the surface. The present study confirmed that removal of cariogenic challenge results in arrest of further dermineralization. The gradual regression of the lesion at the clinical level was believed to be primarily a result of surface abrasion with some redeposition of minerals.
Nutrient and environmental growth factors for eight small‐sized oral spirochetes
Authors: FIEHN NILS‐ERIK , WESTERGAARD JYTTE
Published: October 2007

Abstract —The present investigation was carried out in order to obtain better information about the growth requirements for small‐sized oral spirochetes containing two endoflagella from each cell‐end. Eight strains of such spirochetes were isolated from subgingival plaqueinpatients suffering from advanced marginal periodontitis. The strains were maintained under anaerobic conditions in a fluid basal BHI medium with 15% inactivated rabbit serum, 0.07% Noble Agar and 5 μg/ml cocarboxylase. Firstly, the effect of trace amounts of oxygen in the atmosphere and pH in the medium on growth of the spirochete strains were examined. Secondly, the effect of different sera incorporated in the medium was examined, and thirdly, the effect of important growth factors in serum was studied by adding different serum components to the fluid basal medium instead of rabbit serum. Growth was always determined after 4 days' incubation at 35°C, either by counting numbers of spirochete cells in a Petroff‐Hauser counting chamber or by measuring the turbidity of the culture spectrophotometrically at 600 nm. There was no difference in growth by using an atmosphere containing 1 % oxygen or an anaerobic atmosphere. It was found that serum (rabbit or human) was an essential growth component, and no single growth factor could replace rabbit serum. Only a long chain fatty acid mixture and an amino acid solution could, to a minor extent, stimulate growth compared to the basal medium without rabbit serum. Sodium bicarbonate inhibited growth of all strains. Finally, none of the strains fermented a series of low molecular weight carbohydrates, but ail strains produced H2S and indole.
Electrodermal activity, dental anxiety, and fear of dentistry in a group of parenteral drug addicts
Authors: SCHEUTZ FLEMMING
Published: October 2007

Abstract — The present study was undertaken in order to evaluate whether electrodermal activity was a useful tool with which to measure dental anxiety in a group of drug addicts. Electrodermal activity was compared to the subjects' self‐reported feelings during ordinary dental treatment sessions. In the first part of the study the level of electrodermal activity during treatment sessions was videotaped and recorded on paper by means of a polygraph. The patients were interviewed using a semi‐structured questionnaire dealing with the addicts' dental anxiety and fear. In connection with the interviews the addicts completed Corah's Dental Anxiety Scale (CDAS). There was no recognizable pattern in electrodermal activity when this was compared with the patients' feelings during the treatments. Median CDAS was 9.5. In the second part of the study, electrodermal activity was recorded on the polygraph only. This group also completed a CDAS questionnaire. No correlation between the patients' self‐reported highest level of anxiety and level of electrodermal activity, number of fluctuations or amplitude in relation to specific dental stimuli was found; agreement was found in two, three and none of 10 cases respectively. Median CDAS was 10.0. It could be concluded that, although the study revealed apprehension and situational anxiety among the addicts, no correlation to electrodermal activity was found. This discrepancy between the physiological and cognitive data probably reflects the uncertainty of these measures under the given circumstances.
Corrosion of dental amalgams in solutions of sodium chloride, sodium sulfide and ammonia
Authors: PALAGHIAS GEORGIOS
Published: October 2007

Abstract — Specimens were prepared from three different dental amalgams and were immersed in 0.5% aqueous solutions of sodium sulfide, ammonia and sodium chloride. Every month and over a 6‐month experimental period the solutions were replaced with fresh electrolyte and were analyzed in an atomic absorption spectrophotometer with respect to their content in silver, mercury, copper, tin and zinc. In sulfide solutions large amounts of tin and mercury were released from the amalgams while none of the other elements could be detected. Copper, tin and mercury were mostly dissolved in ammonia solutions. An increased silver dissolution could also be observed. Zinc was the first element to be released in sodium chloride solutions. After a 4‐month immersion, considerable amounts of copper and mercury could also be found in the same solutions.
Enamel apposition rate and the prism periodicity in human teeth
Authors: RISNES STEINAR
Published: October 2007

Abstract – A method is presented which allows the average daily rate of enamel apposition to be estimated based on measurements of the length of prisms in longitudinal ground sections, and on available data for the time of formation of the tooth crown. The method was applied on 21 sections of human maxillary premolars. The reproducibility of the method was satisfactory, the error of measurement being in the order of 3.8%. After corrections having been made for the deviation of prisms from a radial direction, the average daily rate of enamel apposition along the prisms for any maxillary premolar was estimated to be within a range of from 2.0 to 6.1 μm, while a more probable rate would be 2.7–4.6 μm. These results are in agreement with experimental data, and are also compatible with the observed cross‐striation prism periodicity. The present study supports the theory that there exists a relationship between the prism periodicity and a 24‐h rhythm in enamel apposition in human teeth.
Maxillary expansion of unilateral cross‐bite in preschool children
Authors: LINDNER ANDERS , HENRIKSON CARL O. , ODENRICK LARS , MODÉER THOMAS
Published: October 2007

Abstract – The influence of a low force appliance on the maxilla in correction of unilateral cross‐bite was studied clinically and radiographically in 29 preschool children following a standardized treatment schedule. Four weeks' expansion was followed by a 4‐wk retention and a 12‐wk postretention period. Inter‐ and intraobserver evaluations of the reliability of the measurements on radiographs were performed. In all children but one the cross‐bites were corrected after 4 wk of expansion. The mean maxillary expansion was 3.3 mm in the second molar and 1.3 mm in the canine region, but decreased to 1.5 mm and 1.0 mm, respectively, at the end of the postretention period without relapse of the corrected malocclusion. No significant remaining orthopedic effects could be registered on radiographs by this low force appliance used. The modified quad helix appliance was found to be suitable for correction of unilateral crossbite in the primary dentition and was well tolerated by the children.
Local immunoreactivity and human papillomavius (HPV) in oral precancer and cancer lesions
Authors: LIND P. O. , SYRJÄNEN S. M. , SYRJÄNEN K. J. , KOPPANG H. S. , ASS E.
Published: October 2007

Abstract – A retrospective longitudinal study was performed on 20 patients with oral leukoplakia, 10 of which developed an oral squarnous cell carcinoma, to assess whether any alterations in the local immunologic reactivity could be found of value in predicting the subsequent behavior of the lesions. During the major period of follow‐up, the relative frequency of in situ IgA‐producing plasma cells was significantly higher in biopsies from patients subsequently developing cancer than in patients showing no cancer development. Preceding the malignant transformation by 12 to 15 months, however, a remarkable shift from IgA to IgG plasma cell predominance was noticed in the biopsies of the cancer series, not detectable in the non‐cancer group. HPV group specific capsid antigens were found in seven cases of the cancer series and in six of the non‐cancer group. The possible diagnostic implications of these results are discussed.
Fluoride concentrations of the surface enamel of children living in an optimally fluoridated community
Authors: KONTTINEN MARJA‐LEENA , HANHIJÁRJVI HANNU
Published: October 2007

Abstract – The present study was undertaken in a community, where the tap water has been optimally fluoridated since 1959 (1.0–1.2 ppm). The material consisted of 92 children and adolescents including 30 sibling‐couples. The mean age of the participants was 11.8 ± 2.45 (SD) yr. 56 children had consumed fluoridated water all their life, the others only a part of the developmental period of their permanent dentition. Enamel biopsies were taken from 212 permanent teeth and 33 primary teeth by etching the tooth surface for 6 or 30 s. The etch depth was calculated from the mean of dissolved enamel calcium and phosporus. The fluoride concentration in the outermost enamel was almost similar in the teeth of the lifelong residents and the rest of the children. Towards the deeper layers the amount of fluoride decreases depending on its availablity during the development of the enamel. There was no striking similarity neither in the fluoride concentration nor in the amount of dissolved enamel between the siblings when compared with the other children. The posteruptive incorporation of fluoride takes place only on the outermost surface of the enamel. The results suggest that in subsurface layers the fluoride exposure during tooth formation is the dominating determinant of enamel fluoride concentration.
Amalgam‐related oral lichenoid reaction
Authors: LIND PETTER O. , HURLEN BJÖRN , LYBERG TORSTEIN , AAS EIGIL
Published: October 2007

Abstract – In 52 patients with oral lichen planus topographically related to amalgam restorations, the fillings were replaced by other materials in 18, 16 of whom experienced complete remission of the lessions within 1–12 months. These results are discussed in relation to the results of epicutaneous patch tests for possible allergy to a number of mercury compounds. The term “oral lichenoid reaction”, is suggested to describe these lesions.
Effect of effervescent vitamin C preparations on bovine teeth and on some clinical and salivary parameters in man
Authors: MEURMAN J. H. , MURTOMAA H.
Published: October 2007

Abstract – Eight effervescent preparations and one chewable vitamin C preparation were tested with regard to dental erosion by immersing bovine tooth specimens for 100 h in 100 ml of the test solutions. For comparison, two effervescent calcium preparations were studied. All the vitamin C products caused distinct erosion and disclosure of dentin in the specimens which could not be found in calcium preparations. Calcium release from the bovine teeth varied from 1.08 to 12.99 μg Ca/rnm2/h. Softening of the dental tissue assessed as the Vickers hardness units, was most prominent among the specimens where most calcium release was observed. A crossover clinical trial using a test pannel assigned to 1‐week periods of excellent vs no mechanical cleaning, and with a consumption of 6.6 times more vitamin C tablets than the recommended daily use, revealed no particular impact of the preparation on a variety of oral health parameters. Except for a slight stimulation of the subjects' salivary flow rate 30 min after consuming the vitamin C, all other differences observed could be explained by the accumulation of plaque during the period without mechanical cleaning. Thus, in patients with normal salivary flow rate a short‐term consumption of vitamin C preparations, even in excess, may be regarded as harmless from the dental point of view. However, all the studied preparations are potentially erosive if left in direct contact with the teeth.
Biological activity of lipopolysaccharides from oral Selenomonas
Authors: HOFSTAD TOR , NAESS VIGFRID , SKAUG NILS
Published: October 2007

Abstract – Lipopolysaccharides (LPSs) were extracted by phenol‐water From three oral strains of Selenomonas. The preparations were tested for the ability to induce a blastogenic response in cultures of spleen cells from normal and nude BALB/c mice, to activate guinea pig complement and the clotting enzyme system of Limulus polyphemus amoebocytes, and to kill Actinomycin‐D treated mice. The capacity of the three LPSs was comparable to that of enterobacterial LPS.
Reduction of body doses in rotational panoramic radiography by means of reduced beam width in combination with rare earth intensifying screens
Authors: AAGAARD ANETTE , SEWERIN IB
Published: October 2007

Abstract – The absorbed doses in the body of a Rando‐Alderson phantom were measured in rotational panoramic radiography (OP‐5) with LiF‐700 crystals using conventional intensifying screens and standard collimator, as well as rare earth intensifying screens and a collimator slit of reduced width. The reduction of the absorbed doses obtained by using the latter combination was calculated. The reduction range in different regions was 0–50%. The greatest reduction was obtained in the cranial part of the phantom. In the caudal part little or no reduction was observed, probably because leakage radiation contributes substantially to the absorbed doses in this area. The average dose equivalent was calculated for organs in which measurements were made in several locations. The reduction was about 50% for these organs except for the gonads (8%). Compared to the estimated average annual dose equivalent originating from the natural background radiation sources, the dose equivalent resulting from this X‐ray examination was very small except in the thyroid gland. In this organ the dose equivalent from one exposure corresponded to 36 days of natural background radiation, but it could be reduced to 18 days by using rare earth intensifying screens in combination with reduced beam width.
Immunohistochemical studies on colloid bodies (Civatte bodies) in oral lesions of discoid lupus erythematosus
Authors: REIBEL JESPER , SGHIÖDT MORTEN
Published: October 2007

Abstract – By electron microscopy colloid bodies have been shown to be derived from epithelial cells. It has been suggested, however, that connective tissue cells or components from the basement membrane zone contributed to the formation of colloid bodies. In order to examine these possibilities we stained oral lesions of discoid lupus erythematosus (DLE) with antibodies against intermediate filaments (keratin, vimentin), basement membrane components (laminin, collagen type IV) and fibronectin. IgM was used as a marker for colloid bodies. Colloid bodies were stained positive for keratin, whereas vimentin was never found in colloid bodies. Laminin and collagen type IV were occasionally seen in their periphery probably owing to adherence of basement membrane fragments during apoptosis. Fibronectin was frequently seen at the entire periphery of colloid bodies which may facilitate their elimination by macrophages. In conclusion, connective tissue cells or basement membrane components do not seem to contribute to the formation of colloid bodies in oral DLE.