bluuebunny/crossref_metadata_2025 huggingface dataset:
Dental procedures and endocarditis prophylaxis: experiences from 108 dental practices
Authors: GUTSGHIK ERNÖ , LIPPERT SÖREN
Published: October 2007

Abstract – In a previous survey, we analyzed a questionnaire to 220 patients, who underwent cardiac surgery with insertion of prosthetic heart valves in the period 1978–1982. Of the 147 patients with their own natural teeth, 136 gave us permission to contact their regular or casual dentists. Of the 108 dentists (79%), who responded to a questionnaire, two thirds were well aware that their patients had prosthetic heart valve and the vast majority of dentists believed that antibiotic prophylaxis is justified in connection with (certain) dental procedures. However, only 15 dentists (14%) prescribed prophylactic antibiotics, i.e. before scaling. The dosage route, frequency and duration of antibiotic administration used by more than half of the dentists was not in accordance with modern principles of antibiotic prophylaxis to prevent bacterial endocarditis. Proposals for antibiotic regimens have to be linked to better education/information of the patients, doctors and dentists, and should be linked to recommendations to ensure the highest level of dental care in risk patients.
Unilateral, isometric bite force in 8‐68‐year‐old women and men related to occlusal factors
Authors: BAKKE MERETE , HOLM BETTY , JENSEN BIRGIT LETH , MICHLER LARS , MÖLLER EIGILD
Published: October 2007

Abstract – Unilateral bite force was studied in 63 women and 59 men, 8‐68 yr of age. The subjects had a minimum of 24 teeth and no symptoms or signs of disorders of the craniomandibular system. Bite force was stronger in men (522 N) than in women (441 N). It increased with age until 25 yr (P<0.0001). The level decreased significantly after this age in women, whereas it only tended to decrease in men and not until after 45 yr of age. Body height was positively associated with force. However, the strongest correlation (r: 0.43–0.49,p<0.01) with adult bite force was occlusal contact. The normal bite‐force values with important determining factors provide reference data for screening of elevator muscle strength in routine examination of craniomandibular function.
Short‐ and long‐term fluoride release from glass ionomers and other fluoride‐containing filling materials in vitro
Authors: FORSTEN LENNART
Published: October 2007

Abstract – Test specimens of seven different glass ionomer filling materials and one fissure sealant were exposed to running water for 2 yr. One amalgam and one composite, both containing fluoride, were included for comparison. The fluoride release from the specimens was measured periodically after storing the specimens for 24 h or 1 wk in a small amount of water. The fluoride release From the glass ionomers decreased with time and a constant level was reached for most products during the 2‐yr period. The release was increased by lowering the pH of the storage solution. The release from the glass ionomers was clearly greater than from the amalgam and the composite.
Self‐administered use of fluoride among Danish chocolate workers
Authors: PETERSEN POUL ERIK
Published: October 2007

Abstract – In a group of 82 dentate chocolate workers (71% of sample) 61% reported to rinse with 0.2% NaF at least once a month; 75% responded positively to the use of fluoride in prevention of oral occupational disease. The use of fluoride was dominant among the dentally motivated workers. Thus, professionally applied fluoride should be considered for less motivated high risk groups.
Salivary conditions and cariogenic microorganisms in 55, 65, and 75‐year‐old Swedish individuals
Authors: FURE SOLVEIG , ZICKERT INGEGERD
Published: October 2007

Abstract – Secretion rate, buffer capacity, and cariogenic microorganisms of resting and stimulated whole saliva were examined in 208 55‐, 65‐, and 75‐yr‐old Swedes. The secretion rate for both resting and stimulated saliva decreased with age. When the use of drugs was taken into account the difference in terms of age group was significant for resting saliva alone (P<0.01). In 22%, the resting saliva was <0.1 ml/min, and in 5% the stimulated saliva was <0.7 ml/min. Persons with subjective dryness in the mouth had a lower salivary flow. Men had higher secretion rates than women irrespective of medication (P<0.05). The buffer capacity was strongly correlated to the secretion rate of both resting and stimulated saliva (r=0.39 and r=0.44, respectively). The number of mutans streptococci and lactobacilli increased with age, although significant in terms of age group for lactobacilli alone (P<0.05). The number of these microorganisms was lower in resting saliva than in stimulated saliva (P<0.0001). Individuals harboring both Streptococcus mutans and Streptococcus sobrinus had higher values of mutans streptococci in resting and stimulated saliva than those harboring only S. mutans (P<0.001). Actinomyces viscosus and Actinomyces naeslundii comprised 1% of the total CFU in 89% of the plaque samples. The corresponding figures for lactobacilli and mutans streptococci were 6% and 38%, respectively.
Growth conditions and outer membrane proteins of Fusobacterium nucleatum
Authors: BAKKEN VIDAR , HÖGH BENTE T. , JENSEN HARALD B.
Published: October 2007

Abstract – Fusobacterium nucleatum strains ATCC 10953, ATCC 25586, F1 F3, F6, and Fevl were grown in different media. The influence of growth conditions on the outer membrane proteins (OMPs) was analyzed by sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS‐PAGE). There were no apparent differences in the outer membrane protein profiles when cells in the same phase of growth in various rich media were compared. Differences, however, were observed between early logarithmic phase and stationary phase cells. Thus several proteins were only synthesized during late logarithmic and stationary phase. Synthesis of some of these proteins, in particular a 65K and a 14K protein, seemed to depend on the presence of peptides in the medium. In a complete medium, these proteins were synthesized after depletion of some amino acids, and peptides were then utilized.
Correlation between caries experience in primary and permanent dentition in birth‐cohorts 1950–70
Authors: HELM SVEN , HELM TOVE
Published: October 2007

Abstract – Caries experience in the primary molars and canines at 8 yr of age and in the permanent dentition at 16 was correlated in every fourth birth‐cohort between 1950 and 1970 in a Danish community. Correlations between 0.44 and 0.56 were found. Cross‐tabulation of the data also revealed close association, but prediction of individual high caries risk children based solely on screening for caries experience in the primary dentition is hardly cost‐effective.
Non‐specific cleavage of collagen by proteinases in the presence of sodium dodecyl sulfate
Authors: BLEEG HENRY S.
Published: October 2007

Abstract – Proteolytic degradation of collagen normally requires specific collagenases of either mammalian or microbial origin. We have observed, among many detergents, a unique effect of sodium dodecyl (=lauryl) sulfate after preincubation of insoluble collagen (type I) with detergent. When treated fibrils were isolated and resuspended in detergent‐free buffer, they were very sensitive to cleavage by non‐specific proteases like trypsin, elastase, and subtilisin. We suggest that dodecyl sulfate causes a structural change in the collagen molecule which abrogates the resistance of collagen to most proteolytic enzymes. These observations may have implications for collagen and connective tissue research in general and especially to periodontal research. Lauryl sulfate (2‐5%) is included in the majority of toothpaste formulations as a foaming agent, and our results again raise the question whether toothbrushing with lauryl sulfate may accelerate periodontal destruction by synergism with bacterial and host proteases. It may also bind to the collagen in exposed root surfaces and thus affect the stability of their hard tissues.
Strength of bond with Comspan Opaque to three silicoated alloys and titanium
Authors: HANSSON OLA
Published: October 2007

Abstract – In Sweden high‐gold alloys or cobalt‐chromium alloys are used for resin‐bonded prostheses. The bond strength between a resin cement and different sandblasted or silicoated metals were measured before and after thermocycling; in connection with this some rapid thermocycling methods were studied. The effect of different storage times and different protection coatings on bond strength were tested. Finally, the influence of rubbing and contamination with saliva on bond strength were investigated. Silicoating increased the bond strength significantly. The highest bond strengths were these of silicoated Wirobond and titanium, unsusceptible to thermal stress; the bond strengths of the sandblasted metals were the weakest, and sensitive to thermocycling as well. The influence on bond strength for silicoated gold alloys, protected with an unpolymerized composite resin coating, stored in sealed plastic bags up lo 7 days, was negligible. Rubbing and contamination with saliva did not influence bond strength. Preferably, silicoated Wirobond and titanium should be used for resin‐bonded prostheses, but gold alloys may still be adequate for clinical use. The experimental method described for storing, sealing, and cleaning the silicoated metal surfaces in this article can be recommended for laboratory and clinical use.
Color stability of three composite resins used in the inlay/onlay technique
Authors: PEUTZFELDT ANNE , ASMUSSEN ERIK
Published: October 2007

Abstract – The color stability of three composite resins used in the inlay/onlay technique was determined by means of irradiation with UV‐light and by water storage. Generally, water storage resulted in greater changes in color than did UV‐light, but no correlation was found between the results of the two chromogenic procedures. The microfilled composite resin was the least color stable material, but none of the resins had alarmingly low color stability.
Presence of α‐naphthyl acetate esterase enzymes in dental and oral epithelium of guinea pig embryos
Authors: JUHL M. , VILMANN H.
Published: October 2007

Abstract – This study examines the distribution of α‐naphthyl acetate esterase enzymes in reduced enamel epithelium, i.e., post secretory ameloblasts (PSA) and external cells of reduced enamel epithelium (ERE) of continuously growing incisor and molar tooth germs and in the covering oral epithelium (OE). Jaws of guinea pig embryos, 25–50 days of gestation age, were pretreated, frozen, serially cut, and incubated with α‐naphthyl acetate as substrate and hexazotized pararosaniline as capture agent for demonstration of enzyme activity. In addition, sections were preincubated with various inhibitors of enzyme activity. A strong enzyme reaction, essentially unaffected by pretreatment procedures, was demonstrated in all cells of PSA and ERE, and in suprabasal cells of OE. Preliminary characterization of the α‐naphthyl acetate esterase enzymes by means of inhibitors suggests a prevailing presence of B‐esterase enzymes in both oral and dental epithelia, PSA were selectively stained when 2 × 10−3 M arsanilic acid was used as inhibitor, ERE were selectively inhibited by 10−5 M eserine, and cells of OE were selectively stained when 2 × 10−3 M HgCl2 was used as inhibitor. We therefore conclude that the α‐naphthyl acetate esterase enzymes in combination with inhibitors may serve as histochemical markers for discrimination of dental and oral epithelium in the guinea pig prior to eruption of teeth.
Six‐month study of the effect of a dentifrice containing zinc citrate and triclosan on plaque, gingival health, and calculus
Authors: SVATUN BJARNE , SAXTON CHARLES A. , RÖLLA GUNNAR
Published: October 2007

Abstract – In two previous studies gingival health was maintained for at least 12 months by a dentifrice containing zinc citrate and triclosan. The aims of the present study were to determine if a zinc/triclosan dentifrice would stabilize gingival health if a lower concentration of zinc was used and to investigate its effect on the formation of calculus. 101 men and women were given oral hygiene instruction and their teeth were professionally cleaned. Two balanced groups were then formed, based on the prestudy levels of gingival bleeding and calculus. One group used the zinc/triclosan dentifrice for 6 months, while the other used a control. Results were assessed after 3 months and 6 months. Following the oral hygiene instruction, plaque and gingival bleeding were assessed at the end of the 4‐wk period preceding the experimental phase, and both had been reduced. This improvement was not maintained by the control group, whereas the test group exhibited significantly lower plaque levels and a higher standard of gingival health throughout the 6 months. After 3 months, levels of calculus in the control group had returned to prestudy levels. At both the 3‐ and 6‐month assessments, significantly less calculus was observed in the test group. The improved plaque control, stabilized gingival health, and reduced calculus formation support the conclusion that a dentifrice containing 0.5% zinc citrate and 0.2% triclosan can contribute to oral care.
Comparative study on mineralization‐related intraoral parameters in periodontitis‐affected and periodontitis‐free adults
Authors: SEWÓN LIISI , SÖDERLING EVA , KARJALAINEN SÁRA
Published: October 2007

Abstract – The parameters related to an intraoral mineralization tendency in periodontitis‐affected (P+) and periodontitis‐free (P‐) study subjects (16 adults, 46–74 yr, matched for sex and age) were compared. For this purpose the calcium (Ca) and phosphate (P) concentration of both plaque and saliva, resting pH and the acidogenic response of interdental plaque, plaque wet weight, salivary flow rate, buffering capacity and sucrase activity, interdental and salivary S. mutans levels as well as salivary lactobacilli and yeast levels were estimated. Plaque Ca (μg/mg protein, P<0.025) and P (μg/mg protein, P<0.05), saliva Ca (μg/ml, P<0.005) and the saliva Ca:P ratio (P<0.005) were higher in the P+ than in the P‐ group. The resting pH values were higher (P<0.025) and the acidogenic response of the interdental plaque was lower (P<0.025) in the P+ group than in the P‐ group. The P+ group had lower S. mutans levels in saliva and interdental plaque. No differences were found in the wet weight of plaque and in the flow rate, buffering capacity or sucrase activity of saliva between the groups. The findings of the mineralization‐related parameters in the two “extreme” groups of periodontal status suggest a higher intraoral mineralization tendency in periodontitis‐affected persons than in periodontitis‐free subjects. Ca and P accumulation of supragingival plaque seem to be connected with low acidogenicity of plaque and high salivary Ca concentration.
Relationship between dental and skeletal maturation in Danish schoolchildren
Authors: HELM SVEN
Published: October 2007

Abstract – Spearman correlation coefficients between the number of emerged permanent teeth and RUS (TW2 method) skeletal maturity scores were calculated among 1412 boys and 1332 girls, aged 7–14 yr, divided into 3‐month age groups. “Moving averages” are presented of the correlation coefficients for every four 3‐month age groups at a time. The pattern of the correlations differed between the sexes. However, in general, weak associations were found (mean r = 0.15‐0.16), but correlations were significant at the 1%, level in 8.5‐9.5‐yr‐old girls and around 12 yr in both sexes. It is argued that skeletal, rather than dental, maturity should be assessed in adopted non‐European children of unknown chronologic age.
Localization of lysozyme mRNA in the labial salivary glands by in situ hybridization in Sjögren's syndrome
Authors: KONTTINEN YRJÖ T. , KULOMAA MARKKU , SEGERBERG‐KONTTINEN MARGARETHA , NORDSTRÖM DAN , KEINÄNEN RIITTA , GRÖNBLAD MATS , MALMSTRÖM MARIA
Published: October 2007

Abstract – In this study, lysozyme mRNA in labial salivary glands has been localized with in situ hybridization technique using 35S‐labeled hen lysozyme cDNA (cDNALZM) as a hybridization probe in normals and in patients with Sjögren's syndrome. 35S‐DNALZM:mRNA hybrids were detected only in acinar serous cells, although lysozyme was identified in ductal cells using immunohistochemical techniques. Our results suggest that the serous acinar cells are the only site of lysozyme synthesis in small salivary glands. The presence of lysozyme in ductal cells may be a result of reabsorption from the saliva or concentration from the blood or surrounding tissues.
High resolution scanning electron microscopy of the subplasmalemmal cytoskeleton in human odontoblasts
Authors: SÖGAARD‐PEDERSEN BO , BOYE HANS
Published: October 2007

Abstract – The subplasmalemmal cytoskeleton in human odontoblasts was studied by high resolution scanning electron microscopy. The odontoblast layer was isolated and exposed to formaldehyde, glutaraldehyde, and OsO4 for some specimens, while the membraneous structures and soluble proteins in the dental tissue were removed by Zenker's solution and 1% OsO4 for other specimens, without further fixation of the remaining components. The cytoskeletal elements comprised a dense network of interlacing filaments of different diameters in the cell body. Most cytoskeletal elements were parallel to the axis of the cell processes situated inside the dentinal tubules. The appearance and orientation of the investigated subplasmalemmal cytoskeletal elements was unaffected by the choice of method. Both methods confirm the presence of a subplasmalemmal cytoskeleton in human odontoblasts.
Column‐like structures following the course of tubules in human dentin
Authors: HALS EINAR
Published: October 2007

Abstract – Sections, 60–180μm thick, of permanent teeth, intact or with minor fillings, were cut parallel or transversal to the course of the dentinal tubules. Some teeth were dermineralized, embedded in paraffin wax, cut in series, and stained with toluidine blue pH 5.6, hematoxylineosin, or PAS. Altogether, sections of 90 teeth were examined by ordinary and polarized light microscopy and contact microradiography. Alternating light and dark bands, usually 8–30μm wide, extended from the pulpal border along the course of the tubules, gradually increasing in width, fading in the mantle dentin. Cross‐sectioned bands appeared as dark and light “discs”. This was the background for the term “columns”. In the dark columns, usually exhibiting crowding of tubules, the intertubular dentin was dark and radiolucent; in the light columns, light and radiopaque. Dark columns contained a high amount of GAGs, assumed to have exerted an inhibitory effect on their mineralization. The columns probably represent structural elements in the architecture of dentin, possibly offering resistance against mechanical stress. It was suggested that the columns might depict functional differences in the matrix secretion and mineralization capacities of odontoblasts.
Further in vivo studies on the plaque‐inhibiting effect of chlorhexidine and its binding mechanisms
Authors: WAALER SONNI METTE
Published: October 2007

Abstract – The aim of the present study was to investigate the relative importance of chemical groups in the oral cavity which bind chlorhexidine of clinical significance. This was performed by clinical experiments where a test panel of 11 individuals rinsed with chlorhexidine at pH 7, pH 5.5, and pH 3. Rinsing with 0.02 M EDTA was performed prior to the chlorhexidine rinse, because this procedure has been shown to enhance the antibacterial effect of chlorhexidine in vitro. However, pre‐rinses with EDTA did not increase the clinical effect of chlorhexidine. Bacteriologic tests showed comparable antibacterial effect of chlorhexidine at pH 7 and pH 3. Mouthrinses of pH 7 and pH 5.5 had comparable plaque‐inhibiting effects, whereas the effect of a rinse of pH 3 was not different from that of the placebo. This finding is interpreted to suggest that primary phosphate (pK about 2) is an important receptor site for chlorhexidine, whereas secondary phosphate (pK = 7.0) is of negligible importance. Previous studies have clearly shown that phosphate binds chlorhexidine. The lack of clinical effect at pH 3 is probably due to precipitation of salivary proteins by hydrogen ions, making primary phosphate groups unavailable for interaction with chlorhexidine.
Errors in radiographic assessment of marginal bone height around osseointegrated implants
Authors: SEWERIN IB PAUL
Published: October 2007

Abstract – Radiographic assessment of marginal bone height is included in longitudinal control of osseointegrated implants. Previous studies have revealed a mean annual loss of less than 0.1 mm. The purpose of the present study was by means of an experimental model to analyze the influence upon alveolar bone height measures around osseointegrated implants of buccolingual bone dimensions as well as angulations of fixture axis to central X‐ray beam. Brånemark titanium implants were inserted into acrylic test blocks simulating alveolar ridges of various widths. 0.2 mm steel wires visualized buccal and lingual bone margins. Standardized radiographs were obtained by stepwise variation of projection angles. Separation of the wire images varied from 0.1 mm (buccolingual width 5 mm and 1° angulation) to 4.8 mm (width 13 mm and angulation 20°). In clinical cases distortion of buccal and lingual bone margins may result in overestimation of bone heights. The degree of overestimation is influenced by the buccolingual position of the fixture. Strict parallelism between fixture axes and film plane is essential to obtain valid results using single films.
Release of fluoride from conventional and metal‐reinforced glass‐ionomer cements
Authors: HÖRSTED‐BINDSLEV PREBEN , LARSEN MOGENS JOOST
Published: October 2007

Abstract – Fluoride was extracted by 1 or 50 ml deionized water from 0.3 ml samples of two conventional and three metal‐reinforced glass‐ionomer cements. The fluoride concentration was determined by electrode. It was found that the fluoride concentration around the glass‐ionomer cements ranged 2–3 ppm after 15 min and 3–5 ppm after 45 min. The maximum fluoride concentration attained within 24 h varied from 15–21 ppm, while the total amount of fluoride released during 100 days varied from about 2 mg fluoride to 12 mg fluoride per ml glass‐ionomer cement. An alloy reinforced cement and its conventional counterpart released the highest amount of fluoride whereas a glass‐cermet type released the lowest amount. Within the premises of this study it was concluded that composition and handling of the cements are of importance for the release of fluoride, and that a caries inhibitory fluoride concentration can be established in the surroundings of all of the cements.
Familial hypodontia associated with Dupuytren's disease
Authors: RANTA HELENA , KNIF JANNA , RANTA KARI
Published: October 2007

Abstract – A three‐generation Finnish family exhibited hypodontia associated with Dupuytren's disease (contracture). Of the known 32 members of the family, contracture has been diagnosed thus far in 5 individuals, 4 of these also with hypodontia. No other connective tissue involvement was found. For comparison, three other families were studied, also showing incomplete penetrance of hypodontia. Bearing in mind the genetic isolation of the Finnish population, this finding may be coincidental. The possibility of partially common genetic background cannot, however, be excluded.
Hydrophobicities of human polymorphonuclear leukocytes and oral Bacteroides and Porphyromonas spp., Wolinella recta, and Eubacterium yurii with special reference to bacterial surface structures
Authors: HAAPASALO MARKUS , KEROSUO EERO , LOUNATMAA KARI
Published: October 2007

Abstract – The hydrophobicities of human polymorphonuclear leukocytes (PMNLs) and Bacteroides buccae, B. oris, B. oralis, B.veroralis, B. buccalis, B. heparinolyticus, B. intermedius, B. denticola, B. loescheii, B. melaninogenicus, Porphyromonas gingivalis, P. endodontalis, Wolinella recta, and Eubacterium yurii were studied by the hexadecane method. The majority of the strains were equally or less hydrophobic than the PMNLs. Only in the case of E. yurii and the only strain of B. buccalis were all strains more hydrophobic than the PMNLs. However, some strains of B. intermedius, B. oris, B. denticola, and P. gingivalis were also more hydrophobic than the PMNLs. With the exception of B. intermedius and species with a crystalline surface protein layer (S‐layer), the strains of all other species with a thick capsule were more hydrophilic than the strains with little or no extracellular polymeric material. All strains of the S‐layer species were either quite hydrophilic or hydrophobic depending on the species, totally irrespective of the presence of the capsule. The results suggest that the S‐layers of oral anaerobic bacteria may be important determinants of cell surface hydrophobicity.
Effect of fluoride addition on ionized calcium in salivary sediment and in saliva containing various amounts of solid calcium fluoride
Authors: MATSUO SATOKO , RÖLLA GUNNAR , LAGERLÖF FOLKE
Published: October 2007

Abstract – The aim of the present study was to estimate the fluoride concentrations necessary for the precipitation of calcium fluoride or calcium fluoride‐like substances in saliva and salivary sediment, in the presence of various amounts of chemically pure calcium fluoride. Fluoride was added in increments to whole saliva to which solid calcium fluoride had been added. The ionized calcium concentration was determined immediately after centrifugation. In salivary sediments and saliva with no calcium fluoride added the ionized calcium concentration was nearly independent of the fluoride concentration added below 10 and 20 mmol/l, respectively, and at fluoride concentration above 15 and 25 mmol/l, respectively, nearly no ionic calcium was detected. In the presence of calcium fluoride the ionized calcium concentration decreased rapidly with increasing concentrations of fluoride. The more calcium fluoride added, the lower the ionized calcium concentration at a certain fluoride level. The results suggested that in the in vivosituation, caries preventive measures based on frequent oral exposure to low concentrations of fluoride may provide calcium fluoride or calcium fluoride‐like substances, which will serve as a reservoir for fluoride.
Effect of two organic phosphonates on protein adsorption in vitro and on pellicle formation in vivo
Authors: RYKKE MORTEN , RÖLLA GUNNAR
Published: October 2007

Abstract – Organic phosphonates have been introduced in dentifrices to reduce the formation of dental calculus. They may conceivably act as calcium sequestrants or crystal growth inhibitors, interfering directly with the calcium ions on the hydroxyapatite (HA) and enamel surfaces. The aim of the present study was to examine the effect of two organic phosphonates on protein adsorption to hydroxyapatite in vitro and on pellicle formation in vivo. The effect on protein adsorption in vitro was studied by adsorption of albumin to either untreated or phosphonate treated HA powder. Ion exchange chromatography was also performed with columns with untreated and phosphonate treated HA as bed materials and with linear gradients of either phosphate or phosphonates. The effect on pellicle formation in vivo was studied by scanning electron microscopy on untreated and phosphonate treated enamel fragments which had been carried in the mouth to acquire pellicle materials. The present study showed that phosphonate‐treated HA took up less protein. The adsorbed protein was, furthermore, less, firmly bound to phosphonate treated hydroxyapatite. Phosphonate‐treated enamel fragments carried in the mouth also exhibited a slower rate of pellicle formation as compared to the untreated enamel fragments.
Gingival inflammatory reactions in children with rhinoconjunctivitis due to birch pollinosis
Authors: MATSSON LARS , MÖLLER CHRISTIAN
Published: October 2007

Abstract – The present investigation was designed to study the degree of gingival inflammation in children with rhinoconjunctivitis due to birch pollinosis. Thirty‐four children, 8‐17 yr of age, participated. As controls, healthy classmates of the same age and sex were chosen. Dental examination was performed on three occasions: pollen season I (Spring 1987), off‐season (Autumn 1987) and pollen season II (Spring 1988). The controls were examined on one occasion, mixed with the allergic children at the off‐season examination. The degree of gingival inflammation was studied by determining the gingival bleeding tendency by standardized probing. Absence or presence of dental plaque was recorded after sulcular probing. In order to compensate for differences in oral hygiene level between the participants, the bleeding/plaque ratio according to Abbaset al. was calculated. The comparisons of the bleeding/plaque ratios revealed statistically significantly higher mean ratios in the allergic children during pollen seasons compared with offseason and with the controls. The results indicate that during the pollen season, children with allergic rhinoconjunctivitis exhibit an enhanced degree of gingival inflammatory reaction.
Evaluation of some electrical methods for objective assessment of oral mucosal dryness
Authors: HENRICSSON VINCENT , SVENSSON ALVAR , AXÉLL TONY
Published: October 2007

Abstract – The aim of this study was to evaluate different electrical methods (resistance, capacitance and polarization resistance) for clinical and objective registration of dryness of the oral mucosa. Measurements were performed in the buccal and in the lip mucosa before and every 30 min after injection of 1.0 ml methylscopolamine nitrate submucosally in the labial sulcus in 10 healthy subjects. For comparison, a dental mirror sliding test was used. About 1 h after injection, all three methods showed statistically significant decreases, of values in the buccal as well as the lip mucosa except for polarization resistance, which showed such a difference only in the buccal mucosa. The deviations from initial values in the individual subject showed no agreement between measurements with the electrical instruments and oral mucosal dryness assessed with the mirror test. Neither was there any agreement between values registered with the three electrical methods. It seems that these electrical methods are not suitable for registration of individual variations in oral mucosal dryness.
Evaluation of a new device for measuring oral mucosal surface friction
Authors: HENRICSSON VINCENT , SVENSSON ALVAR , OLSSON HÅKAN , AXÉLL TONY
Published: October 2007

Abstract – For the objective measurement of oral mucosal dryness or moisture, a device registering oral mucosal surface slide friction has been developed. Two prototypes, Probe I and Probe II, have been tested. Probe I was constructed for initial testing of the method and was based on easily accessible electrical components. Probe I was computerized and developed for more accurate registration and also for easy handling. Reliability and validity tests were carried out on Probe I as well as on Probe II. In repeated in vitro measurements, the probes showed good reproducibility. Validity was assessed on healthy subjects injected with methylscopolamine nitrate submucosally in the labial sulcus. All subjects experienced a pronounced oral mucosal dryness within half an hour. Registration with the surface slide friction device showed maximum friction values 1‐2 h after injection. These reliability and validity tests gave good results for both Probe I and Probe II, but Probe II had several practical advantages over Probe I. Both probes were considerably more sensitive to changes of the oral mucosal surface than the previously used simple friction test using the back of a mouth mirror.
Collagen fiber reunion in wound repair: transmission electron microscopic study of rat gingiva
Authors: GREVSTAD HANS JACOB
Published: October 2007

Abstract – The purpose of this study was to characterize connective tissue at the site of reunion following surgical injury of the transseptal fiber system in rat molars. Eight conventional albino rats aged 50 days were incised interdentally and the lesions allowed to heal for 14 days followed by specimen preparation for transmission electron microscopy. Four specimens with identifiable areas of fiber attachment at the light microscopic level of magnification were selected for a detailed ultrastructural examination. Transitional connective tissue consisted of thin (250‐375 Å) and thick (450 Å) collagen fibrils at a ratio of 41/59 mainly arranged as aggregates of uniformly sized fibrils. Fibril thickness in the vicinity of fibroblasts (n= 40) varied at a ratio of 65 (thin)/35 (thick). Distribution and spatial arrangement of fibrillar components indicate that the site of reunion is characterized by separate aggregates, of fibrils rather than alignment of individual collagen fibrils of varying thickness suggestive of covalent linkage.
Oral function in patients wearing fixed prosthesis on osseointegrated implants in the maxilla
Authors: LUNDQVIST STURE , HARALDSON TORGNY
Published: October 2007

Abstract – Bite force, chewing efficiency and tactile sensibility were investigated in 21 subjects with OIB (Osseointegrated Implant bridges) in the maxilla or in both jaws. Recordings were performed before treatment, approximately I wk and finally 3–6 months after treatment. The bite force was recorded in the incisor, canine, and premolar areas and was tested at gentle biting, biting as when chewing, and maximal biting. In the chewing tests the chewing time, the chewing velocity, the time to swallowing, and the Ci (Chewing Efficiency Index) were calculated. The occlusal thickness perception was tested in the front with a 12.8 × 10−3 mm thick plastic foil. The maximal bite force was more than doubled, the Ci improved about one index unit, and the occlusal thickness perception improved from on average 57.5 × 10−3 mm to 18.7 × 10−3 mm during the observation time. It is concluded that treatment with upper OIB has a very positive impact on oral function as reflected by improved bite force, chewing efficiency, and occlusal thickness perception.
Flexural and fatigue strengths of root canal posts
Authors: PEUTZFELDT ANNE , ASMUSSEN ERIK
Published: October 2007

Abstract – This study measured the flexural and fatigue strengths of root canal posts of different alloy, design, and diameter. Fixed posts were loaded up to a preset force and the number of loadings endured until fracture was recorded at each loading force. The flexural strength was defined as the maximum force a post could endure before fracture when loaded once. The fatigue strength was determined as the maximum force a post could endure when loaded 10000 times. Both modes of strength were found to increase with increasing diameter. Aluminum posts had lower flexural and fatigue strengths than posts of titanium, stainless steel, and a Ag‐Pd alloy, all of which had strength values of about the same magnitude. Among the investigated brands, Triax and Radix were stronger than the others at comparable diameters. The high strength of Triax may be explained by the design of the post, whereas a superior alloy may account for the high strength of Radix.
Marginal adaptation of resin in relation to application technique and use of a calcium hydroxide liner
Authors: HANSEN ERIK KEITH , ASMUSSEN ERIK
Published: October 2007

Abstract – The marginal adaptation of a restorative resin was examined in cone‐shaped cavities prepared in extracted human teeth. The use of a thin layer of a Ca(OH)2 liner in the bottom of the cavities did not influence the wall‐to‐wall (wtw) polymerization contraction and it did not affect the gap‐reducing efficacy of a dentin‐bonding agent. The wtw contraction was markedly increased when the restorative resin was applied in two layers parallel to the free surface of the cavity; the reason for this is supposed to be that the ratio between the volume of the filling (V) and the area of the cavity wall (A) is increased for the second layer compared to the V/A ratio found in cavities filled with one increment.
Presence of Streptococcus mutans and lactobacilli in saliva and on enamel, glass ionomer cement, and composite resin surfaces
Authors: VAN DIJKEN JAN , PERSSON STEN , SJÖSTRÖM STAFFAN
Published: October 2007

Abstract— The quantity of S. mutans, total streptococci, and lactobacilli on sound enamel surfaces and 1‐yr‐old glass ionomer cement and composite resin fillings with the cervical margins placed subgingivally was compared intraindividually. The amount of bacteria was compared to their number in saliva. The evaluation was done in a cross sectional study, where the patients continued to use their customary oral hygiene procedures and during a 14‐day period of experimental plaque formation. The number of lactobacilli and S. mutans recovered from the test surfaces indicated that the critical salivary concentrations necessary for the isolation of S. mutans and lactobacilli from glass ionomer cement and composite resin surfaces are the same as for the enamel surfaces. The fluoride levels in plaque adjacent to glass ionomer cement will not become high enough to inhibit the accumulation of the investigated bacteria.
Effect of vacuum and supertemperature on mold filling during casting
Authors: HERÖ HAKON , WAARLI MORTEN
Published: October 2007

Abstract— A comparison of the effect on mold filling of using vacuum vs. a protective gas of Ar during casting has been carried Out. A conventional gold casting alloy and a NiCr‐alloy without Be have been cast at three temperatures into two different mold patterns: a mesh screen and a cylindrical crown with a 30° sharp margin. In all cases the application of vacuum rather than a protective gas of Ar was found to be beneficial for the mold filling. A reduction of the back pressure due to the trapped gases in the last part of the mold to be filled with metal was assumed to be the major reason for this effect. A reduced surface tension of the melt may also contribute. An improved mold filling was also observed for both nets and crown margins with increasing supertemperature of the melt. Physical reasons for this effect have been suggested.
Availability of fluoride from glass‐ionomer luting cements in human saliva
Authors: REZK‐LEGA FELIPE , ÖGAARD BJÖRN , RÖLLA GUNNAR
Published: October 2007

Abstract— Fluoride availability from two glass‐ionomer luting agents, Ketac‐Cement and Aqua‐Cement, was monitored after a l‐h treatment in distilled water at pH 7. The recorded results were then compared to the ones obtained from those same cements, after l h, in saliva, in water pretreated with saliva (pH 7 and 4.5), and in albumen and phosphate buffer solutions (pH 7). The Mann‐Whitney two‐sample rank test was utilized in order to identify the differences. The presence of proteins and phosphate reduced fluoride availability. A reduction in the pH from 7 to 4.5 resulted in an increased rate of fluoride release, in water, from glass‐ionomers pretreated with saliva. The present study indicates that fluoride availability from glass‐ionomers, in vivo, is pH controlled. The rate controlling factors appear to be phosphate and proteins.
Use of potentiodynamic polarization technique for corrosion testing of dental alloys
Authors: HOLLAND ROY I.
Published: October 2007

Abstract— The number and in particular the diversity in types and composition of alloys used in dentistry are increasing, thus enhancing the need for predictive corrosion testing. No corrosion test is generally accepted as being both applicable to and relevant for all dental alloys. However, some methods have gained a certain recognition, and among these are the potentiodynamic polarization techniques. The purpose of the present work was to study the application, the reproducibility and the influence of some methodological variables on the results of potentiodynamic polarization corrosion testing. Embedded specimens of 18 different dental alloys, representing all major types, were subjected to anodic polarization scan within the potential range of – 700 mV to 1000 mV (SCE). Artificial saliva, with and without organic compounds, and sodium sulfide solution were used as electrolytes. The results were processed on a microcomputer using locally developed software. The curves of current density versus potential showed fair reproducibility, with great differences between some of the alloys, showing a clear relationship to nobility or passivity of the alloy. There were marked differences between the results obtained in artificial saliva and in sodium sulfide solution, while addition of organic components to the artificial saliva only had a minor effect. The potentiodynamic polarization corrosion test supplies detailed information such as anodic charge, and open circuit, rupture, and passivation potential. Furthermore, it indicates the passive range and sensitivity to pitting corrosion. These are all useful when evaluating the corrosion properties of a dental alloy. An analysis of variance of the results in this study showed that possible differences between the alloys were clearly detectable with this method. However, for alloys releasing non‐ionic products during corrosion/degradation, the method may be inappropriate. It is thus concluded that the method appears applicable as an in vitro corrosion test for most dental alloys, with the possible exception of amalgams.
Age estimation based on tooth development: a test of reliability and validity
Authors: STAAF VERA , MÖRNSTAD HÅKAN , WELANDER ULF
Published: October 2007

Abstract— The precision and accuracy of three commonly used methods for age determination by teeth were studied in 541 children aged 5.5‐14.5 yr. These methods rely on estimation of tooth development as seen in radiographs compared with compiled dental charts. It was found that charts made from Scandinavian populations gave a rather good precision, while one from a Canadian population gave a consistent overestimate. Dependent on the method used, sex, and age, the 95% confidence interval for an individual prediction could be more than ±2 yr.
Influence of phenytoin on cytoplasmic free Ca2+ level in human gingival fibroblasts
Authors: MODÉER THOMAS , BRUNIUS GUSTAF , MENDEZ CARLOS , JUNTTI‐BERGGREN LISA , BERGGREN PER‐OLOF
Published: October 2007

Abstract— Influence of 5,5‐diphenylhydantoin (phenytoin;PHT) on the cytoplasmic free Ca2+ concentration, [Ca2+]i, was studied in fura 2 loaded adherent monolayers of human gingival fibroblasts derived from three patients before and after 9 months of PHT therapy. In the patient where gingival overgrowth developed during PHT medication (responder), addition of PHT to gingival fibroblasts derived before PHT medication induced a transient extracellular Ca2+ dependent increase in [Ca2+]i. In a non‐responder patient, where gingival overgrowth did not develop during the same period of PHT therapy, addition of PHT to gingival fibroblasts derived before the start of medication did not significantly affect [Ca2+]i. Under extracellular Ca2+ deficient conditions, addition of PHT to serum‐starved fibroblasts derived from the two categories of patients before the medication resulted in an increase in [Ca2+]i. In fibroblasts derived from the responder patient during PHT medication, in contrast to those from the non‐responders (n = 2), the basal level of [Ca2+]i was significantly decreased. The results indicate that, in the cases studied, there is a relationship between PHT induced alterations in [Ca2+]i in gingival fibroblasts and the clinical development of gingival overgrowth.
Hypersensitivity reactions to dental materials in patients with lichenoid oral mucosal lesions and in patients with burning mouth syndrome
Authors: SKOGLUND ANNIKA , EGELRUD TORBJÖRN
Published: October 2007

Abstract— Epicutaneous patch testing of a battery of 35 dental test substances was carried out in 24 patients with visible lichenoid oral mucosal lesions and in 24 patients with burning mouth syndrome (BMS) without any visible lesions. Reactions to mercury ammonium chloride were found in 33% (8/24) of the patients with visible lesions compared to 0% (0/24) of the patients with BMS. The difference was statistically significant. In 7 of the 8 patients who reacted to mercury, total or partial regression of the lesions was observed after removal of dental amalgam. Reactions to nickel sulfate were found in 21% (5/24) of the patients with BMS compared to 3% (1/24) of the patients with lichenoid lesions. This difference was also statistically significant. Nickel is a rare component in dental restorations, but the oral mucosa is daily exposed to nickel through food and water intake. Removal of nickel from the environment of the patient can therefore be hard to accomplish.
Short‐ and long‐term fluoride release from glass ionomer based liners
Authors: FORSTEN LENNART
Published: October 2007

Abstract— The aim of the study was to measure the fluoride release from glass ionomer based liners/bases after storing the specimens for 24 h and for 6 months in running water. The fluoride release was greater in the beginning than after half a year. From most liner materials the initial and the long‐term release was greater than from the glass ionomer filling material studied for comparison. From two liners the release was minimal, just at the detection limit.
Distortion of impression materials used in the double‐mix technique
Authors: PETERSEN GERT FORUM , ASMUSSEN ERIK
Published: October 2007

Abstract— According to the so‐called double‐mix technique for impression taking, a material of high and one of low viscosity set against each other. We found that a distortion of the joined materials occurred which may compromise the precision of the impression. The distortion of such combinations of materials of high and low viscosity was measured on beam‐like specimens. Significant differences between materials were observed. The phenomenon may be explained by a swelling of the material of low viscosity. The swelling may be associated with a diffusion of unreacted compounds from the material of high viscosity into the material of low viscosity. Measurements of the swelling of specimens immersed in the catalyst component of unset material showed an increase in length of 2‐5%.
Column‐like structures of human dentin in carious and artificial lesions
Authors: HALS EINAR
Published: October 2007

Abstract— Serial sections of 36 human teeth with minor to medium‐sized carious lesions, adequate sections from previous studies of artificial lesions adjacent to fillings of amalgam (AM), silicate cement (SI) and glass ionomer cement (GI) were studied by ordinary light microscopy and microradiography. Six artificial primary root lesions were included. In carious lesions, dentin columns were visible in the demineralization zone and partly also in the translucent/radiopaque zone. A typical feature of the artificial lesions adjacent to SI fillings was highly radiopaque columns alternating with radiolucent ones. In the GI group such columns were seen at the cavity wall and the advancing front of the outer lesion. In the AM group dark columns were unveiled as pegs in the latter localization. The findings led to the assumption that the dark columns of intact dentin are preferred pathways of acid diffusion in artificial and, possibly, carious lesions. Increased radiopacity of columns in the SI and GI groups is explained by continued exposure of the tooth surface to fluoride dissolved from these fluoride‐rich filling materials.