bluuebunny/crossref_metadata_2025 huggingface dataset:
Iron staining of the acquired enamel pellicle after exposure to tannic acid or chlorhexidine: preliminary report
Authors: NORDBÖ HAKON , ERIKSEN HARALD M. , RÖLLA GUNNAR , ATTRAMADAL AUDUN , SOLHEIM HALVOR
Published: October 2007

Abstract – Extrinsic discoloration of teeth following a large consumption of tannin‐containing beverages or a prolonged use of chlorhexidine mouthrinses is a well known observation. Tannins as well as chlorhexidine are denaturing agents. Based on preliminary studies revealing the presence of iron in chlorhexidine discolored pellicle material, the ability of iron to stain the integument after pretreatmentwith the two denaturants was studied in a human model. The denaturing effect of an acidic environment was also included. Enamel slabs fixedto acrylie appliances were carried in the oral cavity and alternately exposed to the test solutions in different sequences in vitro. Pretreatment with chlorhexidine or tannic acid led to marked discolorations upon iron application during 5‐d tests, whereas the compounds individually had no such effect. A large content of the metal was found in the stained material. Stannous fluoride appeared to reduce the formation of the pigments, and strong oxidation completely bleached the established color. Possible mechanisms underlying the phenomena observed are discussed.
Orientation of orthogonal coordinate systems used for registration of cephalometric landmarks
Authors: McWILLIAM JOHN S.
Published: October 2007

Abstract – Accurate orientation of orthogonal coordinate systems facilitates repeated registration of cephalometric landmarks, addition of new data at a later date and the evaluation of superimposional methods in longitudinal analysis. The precision of a template designed to mark radiographs with four fiducial points was examined. It was found that the envelopes of error surrounding each point were circular, of similar magnitude and closely approached the previously established standard error of the measuring instrument employed. It was concluded that for most practical purposes the precision offered by the template was well matched to that of the coordinatograph used for registering cephalometric data and to the ability of the operator to align the instrument.
Observations on giant tubules in human coronal dentin by light microscopy and microradiography
Authors: HALS EINAR
Published: October 2007

Abstract – Human coronal dentin was studied by light microscopy and microradiography. The material comprised 50 permanent and 10 primary anterior teeth and microradiographs of 63 primary anterior teeth from a previous study. Both intact and worn teeth were examined. Ground sections in the long axes of the crowns in the buccolingual and mesiodistal planes were prepared, as well as transverse sections. A few crowns were also examined in toto. A system of giant tubules extending from the border of the pulpal cavity could be followed, though not continuously, through the secondary and primary dentin almost to the incisal dentinoenamel junction was observed. The lumina of the tubules were 5–40 μm wide and bordered by an approximately 10‐μm‐wide, usually hypermineralized rim of dentin in which only a few dentinal tubules were clearly discernible. The giant tubules were located along the mesiodistal axes of the teeth. The number of such tubules varied between 0 and 30.
Effect of xylitol and other carbon sources on the cell wall of Streptococcus mutans
Authors: TUOMPO HELENA , MEURMAN JUKKA H. , LOUNATMAA KARI , LINKOLA JAAKKO
Published: October 2007

Abstract – Transferring actively growing bacteria or Streptococcus mutans ATCC 27351 into a xylitol‐containing reaction mixture caused distinct alterations in bacterial ultrastructure without notable effect on the total viability of the strain. Incubations in media containing 50 mg/ml of glucose, fructose, sucrose, lactose, sorbitol or mannitol as the primary carbon source did not affect bacterial ultrastructure. These fermentations were reflected biochemically in the amounts of insoluble glucans, as expected. A negative correlation was found between the cell mass and the lipoteichoic acid formation. But these aspects could not be visualized in the electron microscope. In the xylitol series, however, degrading cells and autolysis, intracellular vacuoles and lamellated formations in the cytoplasmic membrane were frequently seen independent of the concentration of xylitol in the reaction mixtures. In freeze‐fracturing replicas, however, the membrane intercalated particles of the cytoplasmic membranes seemed to be unaffected and like those in the controls. Minor ultrastructural changes in the fracture‐faces were detected. Despite the alterations in ultrastructure of the xylitol‐incubated bacteria, there was no difference in their viability when compared to the controls.
Clinical, microscopical and biochemical investigation of synovial fluid from temporomandibular joints
Authors: KOPP SIGVARD , WENNEBERG BENGT , CLEMENSSON ELISABET
Published: October 2007

Abstract – The aim of this study was to investigate the relationship between pain and tenderness to palpation of the temporomandibular joint (TMJ), radiographic changes of the joint and signs of inflammation in the synovial fluid. Saline was injected into and aspirated from the TMJ of 29 patients with painful and tender TM joints and from five individuals with healthy joints. In another two patients synovial fluid could be aspirated without saline. The aspirated fluid was analyzed for inflammatory cells and for plasma proteins. A clinical examination of the stomatognathic system and a radiographic examination of the TMJ were performed before the aspiration. Besides tenderness to palpation of the TMJ, pain on mandibular movement and tenderness to palpation of the masticatory muscles were common. Erosion of the cortical outline of the joint surfaces was the most common radiographic finding. Inflammatory cells were present in the fluid of three patients but in none of the healthy individuals. Plasma proteins of inflammatory type could be detected in the fluid from seven of the patients. The results show that radiographic, cellular or biochemical signs of inflammation can frequently be found in the TMJ of patients with longstanding pain and tenderness of this joint.
Retention of Cu and Zn in the oral cavity following rinsing with aqueous solutions of copper and zinc salts
Authors: AFSETH JOHN , HELGELAND KRISTEN , BONESVOLL PER
Published: October 2007

Abstract – Retention of Cu and Zn in the mouth after rinses with known volumes of aqueous solutions of the metal salts was measured by atomic absorption. The mean amounts retained in 10 subjects were 0.02 mg Cu and 0.22 mg Zn. These values represent approximately 31 % of the Cu and 15% of the Zn originally in the rinse. The intraindividual variation (s.d.), estimated by three mouthrinses at weekly intervals in three subjects averaged 2.1% for Cu and 2.3% for Zn. Following a rinse the salivary concentration of Cu and Zn decreased rapidly during the first 4 h, approaching premise levels.
Effects of therapeutic and pulp protecting materials on nerve transmission in vitro
Authors: BRODIN PÅL , ÖRSTAVIK DAG
Published: October 2007

Abstract – Effects of therapeutic and pulp protecting dental materials on nervous tissue were studied in an in vitro model utilizing the isolated left rat phrenic nerve. The nerve was placed in a buffer bath between two suction electrodes, one for electrical stimulation and one for recording. Evoked compound action potentials (cAP) were monitored in an oscilloscope. Fresh mixes of six commonly used pulp‐dentin materials were placed in contact with the nerve, and the cAP registered. Formocresol, zinc oxide‐eugenol (ZOE), Calasept® and Dycal® caused a complete depression of the nerve activity within 0.5 to 5 min of contact. The depression appeared irreversible with Formocresol and Calasept, reversible with Dycal, and reversible with ZOE when applied to nerves surrounded by adherent fatty tissue. De Trey Zinc® and Durelon® caused only a minor depression of the cAP within 30 min of contact.
Gastrointestinal and in vitro release of copper, cadmium, indium, mercury and zinc from conventional and copper‐rich amalgams
Authors: BRUNE DAG , GJERDET NILS , PAULSEN GUNNAR
Published: October 2007

Abstract – Particles of a conventional lathe‐cut, a spherical non‐gamma 2 and a copper amalgam have been gastrointestinally administered to rats for the purpose of evaluation of the dissolution resistance. The animals were sacrificed after 20 hrs. The contents of copper, cadmium, indium, mercury and zinc in kidney, liver, lung or blood were measured using nuclear tracer techniques. From a copper amalgam an extreme release of copper was demonstrated. This study simulates the clinical condition of elemental release from swallowed amalgam particles after amalgam insertion or after removal of old amalgam fillings. Specimens of the same types of amalgams were also exposed to artificial saliva for a period of 10 days. The amounts of copper and mercury released were measured with flame and flameless atomic absorption spectrophotometry respectively. The levels of copper and mercury released from the copper amalgam were approximately 50 times those of the two other amalgam types studied.
Histopathology of benign gingival fibroblastic lesions with special reference to odontogenic fibroma and recurrence rates
Authors: GÖRREL CECILIA , LARSSON ÅKE
Published: October 2007

Abstract – Histopathologic and clinical reexamination of 84 cases diagnosed as peripheral odontogenic fibroma showed 56 cases with no evidence of recurrence, 12 with possible single recurrence and 16 with verified single or multiple recurrences. An effort was made to correlate the histopathologic appearance with the recurrence rate. Three different types of lesions could be identified: fibrous epulis, calcifying fibroblastic granuloma and various types of “fibroma”, all showing a high recurrence rate. Our findings show that neither histomorphology nor recurrence rate can be used as a definite criterium to separate neoplasia such as odontogenic fibroma from other gingival fibrous overgrowths.
Three‐dimensional replicas of pit and fissure morphology in human teeth
Authors: JUHL MARIANNE
Published: October 2007

Abstract – Nuva Seal® replicas of pits and fissures from surgically removed unerupted human third molars and premolars, and from erupted premolars extracted for orthodontic reasons, were examined in the scanning electron microscope. The results confirm that the morphology on occlusal surfaces of third molars is extremely variable with numerous pits of considerable length positioned at various angles relative to the fissures. In contrast, the morphology of unerupted and erupted premolars is simpler with fewer and shorter pits positioned perpendicular to the fissure. It is pointed out that line details of the morphology are lost when reconstructions of the occlusal morphology are made from serial ground sections. However, such reconstructions seem to be less reliable in third molars than in premolars.
Polarized light study of giant tubules in human and red deer coronal dentin
Authors: HALS EINAR
Published: October 2007

Abstract – Previously described giant tubules in human and red deer coronal dentin have been subjected to a study by polarized light microscopy. Structure of the giant tubules was similar in both species. The lumen of each tubule was bordered by a 5–15‐μm‐thick collagenous mantle in which the fibers were orientated parallel to its long axis. In a circular dentin area encompassing the mantle, the course of the collagen fibers might be characterized as a winding of fibers around the cylindrical mantle. This structure of the giant tubules conforms with that described earlier in the rudimentary maxillary canine of a red deer. Thus, such tubules do not represent a rare anomaly, but occur regularly in both human and red deer coronal dentin.
Effect of SnF2, administered as mouthrinses or topically applied, on Streptococcus mutans, Streptococcus sanguis and lactobacilli in dental plaque and saliva
Authors: SVANBERG MONA , WESTERGREN GUDRUN
Published: October 2007

Abstract – Mouthrinsing with SnF2 reduced the Streptococcus mutans population in plaque and saliva and the proportion of Streptococcus sanguis in plaque. The effect was of short duration: 2 weeks after treatment the values of S. mutans in plaque and saliva were even higher than the pretreatment values. Topical SnF2 applications reduced the S. mutans population in plaque and saliva but did not reduce the proportion of S. sanguis in plaque. The eflect was more prolonged: 4 weeks after treatment the S. mutans population in interproximal plaque remained significantly reduced and the salivary levels of the organism had not fully returned to pretreatment levels. Both SnF2 treatments significantly increased the salivary levels of lactobacilli. The values of laclobacilli in saliva remained signilicantly increased 4 weeks after the SnF2 mouthrinsing but had almost returned to pretreatment levels within 2 weeks after the topical SnF2 applications. The findings suggest that the cariogenic potential of dental plaque is differently affected depending on whether a drug is administered as a mouthrinse or is applied topically.
Evaluation of glass ionomer luting cements
Authors: FINGER WERNER
Published: October 2007

Abstract – In the present study the three glass ionomer luting cements available on the Scandinavian market in June, 1982 were evaluated by comparison with a zinc phosphate and a zinc carboxylate cement. The following properties were tested: effective maximum grain size, retention, strength, bond strength to dentin, disintegration in and absorption of water and solubility in 0.001 n lactic acid. The glass ionomer cements proved to be fully acceptable luting materials.
Methylation of mercury from dental amalgam and mercuric chloride by oral streptococci in vitro
Authors: HEINTZE ULF , EDWARDSSON STIG , DÉRAND TORE , BIRKHED DOWEN
Published: October 2007

Abstract – The capacity of the oral bacteria Streptococcus mitior, S. mutans and S. sanguis to methylate mercury was investigated in vitro. Mercuric chloride and pulverized dental amalgam in distilled water, respectively, were used as sources of mercury. Methylmercury was found in the bacterial cells of all three tested strains. The results indicate that organic mercury compounds may be formed in the oral cavity.
Bonding of restorative resins to dentin by means of methacryloylchloride and methacryloyl‐R‐isocyanate
Authors: ASMUSSEN ERIK , MUNKSGAARD ERIK CHRISTIAN
Published: October 2007

Abstract – The bonding of restorative resins to dentin by means of an intermediary monomer containing a carboxylic acid chloride or an isocyanate group was investigated. Such intermediary monomers are supposed to react with the organic constituent of dentin. Bond strengths were enhanced by the use of the intermediary monomers, resulting in mean bond strengths of 0.13 kg/mm2. Bond strengths of this order of size are probably too low to be of clinical interest.
Abrasion of microfill restorative resins in Class 1 cavities
Authors: KNUDSEN MARIANNE BUNDGAARD , JÖRGENSEN KNUD DREYER
Published: October 2007

Abstract – Abrasion of Class 1 microfill restorations has been studied over a period of 2 years. The materials used were the commercial products Isomolar (Ivoclar, Liechtenstein) and Silar (3 M Co., U.S.A.). All fillings were placed in permanent mandibular first molars of Copenhagen schoolchildren. The abrasion for Isomolar (29 fillings) was found to be 9.8±10.3 (range −9 to 28) μm per year, and for Silar (27 fillings) 11.8±13.0 (range −5 to 41) μm per year. Statistically no difference could be demonstrated between the two products.
Effect of seven inhibitors on invertases in homogenates of human dental plaque
Authors: FIEHN N.‐E. , MOE D.
Published: October 2007

Abstract – Seven known α‐glucosidase/β‐fructosidase inhibitors were examined for inhibitory effect against invertases in pooled human dental plaque. The inhibitors used were acarbose, Trestatin, nojirimycin, 1‐deoxynojirimycin, glucono‐δ‐lactam, conduritol‐B‐epoxide, and Hoe 467A. Plaque homogenates were incubated with l4C‐labelled sucrose and invertase activity was assayed by determination of radio‐labelled monosaccharide after paper chromatography. Conduritol‐B‐epoxide, acarbose, and Trestatin reduced the invertase activity an average of 62%, 51%, and 35% respectively. The other inhibitors affected the enzyme activity negligibly. By combining conduritol‐B‐epoxide with acarbose or Trestatin in other plaque homogenates the inhibition of invertases increased from 35% to 61%. This observation supported the concept that the invertases in dental plaque consist of both α‐glucosidases and β‐fructosidases.
Deposits of immunoglobulins and complement factor C3 in human dental periapical inflammatory lesions
Authors: JOHANNESSEN ANNE C. , NILSEN RUNE , SKAUG NILS
Published: October 2007

Abstract – Thirty‐five human dental periapical lesions were studied by immunofluorescence technique using polyclonal anti‐IgG (F(ab)2), anti‐IgM (F(ab)2), anti‐IgA (F(ab)2), anti‐IgE and anti‐C3c as well as monoclonal anti‐IgE. Prewashed ethanol‐fixed specimens showed a great number of plasma cells staining for IgG. Cells containing IgA, IgM or IgE were also seen. Deposits of immunoglobulins and C3c suggestive of immune complexes were demonstrated using a double staining technique combining FITC‐labeled immunoglobulins with TRITC‐conjugated C3c. The complexes were located intracellularly in macrophages, as well as in vessel walls and in the basement membrane zone of proliferating epithelium. Immune complexes may be involved in the epithelial proliferation in those granulomas which lead to cyst formation. Monoclonal anti‐IgE demonstrated plasma cells and mast cells, as well as intercellular IgE in epithelial strands of granulomas. The role of IgE in the epithelium is obscure. The study strongly indicates the involvement of hypersensitivity reactions type I and III in periapical inflammatory lesions.
Radiographic evaluation of endodontic therapy and the influence of observer variation
Authors: REIT CLAES , HOLLENDER LARS
Published: October 2007

Abstract – In radiographic evaluation of the results of endodontic therapy the development or persistence of periapical radiolucencies often serve as criteria for therapeutic failure. In the present study the influence of inter‐ and intraexaminer variation on these results was investigated. Three endodontists and three radiologists interpreted periapical conditions and quality of root filling seal in radiographs of 119 endodontically treated roots. Consensus on the pretence of periapical lesion was reached in 27% of cases classified as pathologic. In 6% reports of increased width of the periodontal membrane space accorded. The examiners agreed completely on normal periapical conditions in 37% of the cases. On assessing the quality of root filling seal the opinions of observers differed even more. Complete agreement on cases with adequate and defective seal was reached in 25% and 12%, respectively. For the individual examiner the widened periodontal membrane space was the diagnosis most difficult to reproduce. The present study indicates that the large variation noted among clinical and radiographic studies on the results of endodontic therapy could partly be explained by difficulties in defining and maintaining criteria for radiological evidence of periapical disease.
Application of statistical decision theory to radiographic diagnosis of endodontically treated teeth
Authors: REIT CLAES , GRÖNDAHL HANS‐GÖRAN
Published: October 2007

Abstract – The presence or absence of periapical radiolucencies, after a predetermined healing period, have been used as a criteria for therapeutic success or failure in endodontic treatment. However, in radiologic diagnosis it has been shown that variations within and between examiners are substantial. In the present study six endodontists evaluated the periapical tissues in radiographs of 119 endodontically treated roots using a five‐graded rating scale. An earlier study on the same radiograph material served as reference and “true” states of the periapical tissues were established. True positive and false positive reports on the presence of periapical lesions could then be calculated. For each observer it was noticed that a higher true positive percentage always was coupled with a higher false positive percentage and vice versa. If pairs of true positive and false positive percentages were plotted on a two‐dimensional graph they corresponded well to a Receiver Operating Characteristic (ROC) curve. Variations between the observers could be explained by their adoption of different criteria of periapical disease resulting in different positions on the ROC curve. Influence of observer variation on reported frequencies of periapical lesions was greater, the lower the prevalence of the disease. The best Opportunities for revealing relative differences in disease prevalences was created when the examiner defined a strict criterion for disease and reported a positive finding only when absolutely certain.
Thermocamera studies of nitrous oxide dispersion in the dental surgery
Authors: CARLSSON PALLE , HALLÉN BÖRJE , HALLONSTEN ANNA‐LENA , LJUNGQVIST BENGT
Published: October 2007

Abstract – Nitrous oxide is used in dentistry for sedation and analgesia. Chronic occupational exposure of dental personnel to trace concentration of nitrous oxide has been reported as a potential health hazard. A new application of the thermocamera technique was used to study the dispersion of nitrous oxide during dental analgesia. Four breathing systems with different evacuation systems were tested and found to vary in scavenging efficiency. A local exhaust system ensured minimal exposure when nitrous oxide leaks contaminating the air in the dentist's breathing zone occur.
Regional variations in viable bacterial and yeast counts of 1‐week‐old denture plaque in denture‐induced stomatitis
Authors: BUDTZ‐JÖRGENSEN EJVIND , THEILADE ELSE
Published: October 2007

Abstract – Quantitative cultural studies of yeasts and bacteria were made from 1‐week‐old denture plaque accumulated on pieces of self‐adhesive tape stuck on the fitting surface of the maxillary denture in four well‐defined locations. A tape piece was also stuck on the buccal denture flange. The cultural examinations were made in 15 patients with denture‐induced stomatitis which affected most of the denture‐bearing mucosa. There was no significant difference of the bacterial counts from the different sampling areas although the variations between patients was significant. The yeast counts from the test area located on the buccal denture flange were significantly lower than those originating from the fitting denture surface. On the other hand, there was no significant variation of the yeast counts when comparing the test areas of the fitting denture surface. In 12/15 of the patients yeast counts of 103/cm2 were obtained from the fitting denture surface. The results indicate that the environmental conditions beneath a denture base predispose for yeast colonization and are different from those present on the buccal flange.
Histochemical demonstration of activity of acid phosphatase and β‐glucuronidase in bovine incisor tooth germs
Authors: KIRKEBY SVEND , SALLING ELISABETH , MOE DENNIS
Published: October 2007

Abstract – Activity of acid phosphatase and β‐glucuronidase was shown in bovine preodontoblasts and preameloblasts prior to the onset of secretion. In the preameloblasts the rather weak reaction consisted of small discrete granules dispersed in the cytoplasm apical, lateral, and proximal to the nucleus. After initiation of enamel formation, a change in localization and intensity of the colored reaction product was observed in the ameloblasts. The activity appeared stronger and was restricted to a narrow zone just apical to the nucleus. It is proposed that the acid hydrolases in the tooth forming cells are located to the Golgi complex. The differences in activity of acid hydrolases between bone and tooth forming cells are expounded.
Observer variability of and comparison between visual and central bearing point methods of evaluating denture occlusion
Authors: BERG EINAR , KNUDSEN GERHARD
Published: October 2007

Abstract – Central bearing point and visual methods were used in the study of repeated recordings of occlusion in 30 patients with old complete dentures. The results were classified into di‐ and trichotomous categories. Intra‐ and interexaminer variability were generally high. In addition, significant differences were found between the examiners in the level of recording denture occlusion. The use of trichotomous categories increased the variability to an unacceptable level. The variability with the central bearing point method was higher than with the visual method. However, occlusal discrepancies were found with significantly higher frequencies with the central bearing point method than with the visual method.
Streptococcus mutans establishment and dental caries experience in children from 2 to 4 years old
Authors: ALALUUSUA SATU , RENKONEN OLLI‐VEIKKO
Published: October 2007

Abstract – 39 children were studied longitudinally at the age of 2, 3, and 4 yr for the colonization of S. mutans in plaque and saliva and for caries experience. S. mutans was found in 38% of the children, and the predominant serotype group was c/e/f. A total of 16 children got caries before the age of 4. Children who harbored S. mutans in their plaque at the age of 2, appeared to be the most caries‐active individuals. Their caries index values (number of decayed, missed and filled surfaces, dmfs = 10.6±5.3) at the age of 4 differed significantly from the values of children who harbored S. mutans later (dmfs = 3.4±1.8,P<0.005) or remained free from S. mutans infection (dmfs = 0.3±1.1, P<0.0003). It was thus concluded that the early establishment of S. mutans in the plaque of primary incisors indicated early and extensive caries attack in young primary dentition.
Isolation and ultrastructure of Bacteroides sp. with external cell‐wall layer (S‐layer) in periapical osteitis
Authors: RANTA HELENA , LOUNATMAA KARI , HAAPASALO MARKUS , RANTA KARI
Published: October 2007

Abstract – Bacteroides sp. was isolated in human periapical osteitis and shown to be biochemically closely related to B. ruminicola ssp. brevis and B. capillus. Electron microscopic examination revealed an external cell‐wall layer (S‐layer). The fractionation of cells by various methods gave partially purified sheets corresponding to the observed layer with a hexagonal molecular arrangement.
Comparison of two different methods of polishing porcelain
Authors: BESSING CHRISTER , WIKTORSSON ÅKE
Published: October 2007

Abstract – The surface roughness of polished porcelain was investigated. The results showed that no significant differences between the two polishing methods used were found. The two evaluation methods, surface roughness measurements and scanning electron microscopy (SEM), are discussed and some recommendations are given.
Rationale for consistency in the use of enamel surface terms: perikymata and imbrications
Authors: RISNES STEINAR
Published: October 2007

Abstract–

The use of the enamel surface terms perikymata and imbrications/imbrication lines in the dental literature is inconsistent and therefore confusing. Based on an analysis of these terms and their original use, the following system for their future use is recommended: the whole pattern of ridges and grooves on the enamel surface is termed perikymata or imbrications. Distinction between the two elements of the pattern is attained by adding ridge/crest or groove/furrow. In such combination terms perikymata should be used in its singular form, perikyma, e.g. perikyma ridge.
Influence of doxorubicin on rat incisor mesenchymal cells
Authors: DAHL JON EINAR
Published: October 2007

Abstract – Three groups of female Wistar rats were intravenously injected with the antineoplastic drug doxorubicin in a single dose of 5 mg/kg, 10 mg/kg and 20 mg/kg, respectively. The animals were killed 1 and 5 days after injection. Paraffin and Vestopal W embedded sections were prepared of the maxillary right and left incisors, respectively, and evaluated by light microscopy. Doxorubicin produced necrosis of single cells, of small groups of cells in the basal pulp and destroyed the preodontoblasts as evaluated 1 day after injection. On the 5th day of observation, the late preodontoblasts and basal pulp had regenerated, but the early preodontoblast zone remained absent, leading to an abnormal odontogenesis. This caused a marked reduction of dentin deposition in the apical part of the tooth and production of irregular predentin by cells in the pulp and by the young odontoblasts.
Degradation in vivo of the C3 protein of guinea‐pig complement by a pathogenic strain of Bacteroides gingivalis
Authors: SUNDQVIST GÖRAN K. , CARLSSON JAN , HERRMANN BJÖRN F. , HÖFLING JOSÉ F. , VÄÄTÄINEN ANNA
Published: October 2007

Abstract – The pathogenicity of five black‐pigmented strains of Bacteroides was tested in subcutaneously implanted Teflon cages in guinea pigs. The tissue reaction around the cages was registered and the contents of the fluid of the cages were analyzed. Two strains of B. intermedius produced a localized abscess around the cages, while one strain (381) of B. gingivalis and an asaccharolytic strain (BN11a‐f) different from B. gingivalis did not induce any signs of abscess formation. One strain (W83) of B. gingivalis caused extensive purulent breakdown of the tissues. When the inoculum of strain VV83 contained more than 109 cells, the animals were killed. Strain W83 was the only strain that increased in number in the cage. The fluid of cages inoculated with strain W83 was also remarkably different from the fluid of cages inoculated with the other strains. The fluid had a high proteolytic activity. No C3 protein of complement and only traces of immunoglobulins could be detected in the fluid. Both strain W83 and strain 381 had a high proteolytic activity against whole guinea‐pig serum and when bacteria of these two strains were incubated with guinea‐pig serum for 24 h, almost all serum proteins, including the C3 protein, were degraded. These two strains might thus have similar capacity in perturbing the host defence when inoculated into the tissue cages. The actual difference in pathogenicity between the strains might be explained by a recent finding that the pathogenic strain W83, but not strain 381, requires complement in activating polymorphonuclear leukocytes. The degradation of the C3 protein by the pathogenic strain W83 of B. gingivalis thus may be the crucial event in its perturbation of the host defence. A degradation of the C3 protein by strain 381 would be of no help in eluding the host defence, since this strain activates polymorphonuclear leukocytes in the absence of complement.
Attachment of Treponema denticola to cultured human epithelial cells
Authors: OLSEN INGAR
Published: October 2007

Abstract – The present electron microscopic study visualizes adherence of Treponema denticola, the most common treponeme of the gingival crevice in man, to human epithelial cells in vitro. The number of organisms adhering to the cells increased with increase in the treponemal concentration from 106 cells/ml through 108 cells/ml. Epithelial cells immediately after mitosis were particularly rich in treponemes. The number of adsorbing treponemes was reduced after pretreatment of the epithelial cells with hyaluronidase. The epithelial cells showed no predilection site of treponemal attachment. Treponemes attached preferably by their ends. Intracellularity of treponemes was not regularly attained. Treatment with ruthenium red, acidic bovine albumin or hyaluronidase indicated presence of acidic mucopolysaccharides on the treponemal and epithelial cell surface.
Factors predicting caries risk in children
Authors: HONKALA EINO , NYYSSÖNEN VILJO , KOLMAKOW SERGEI , LAMMI SEPPO
Published: October 2007

Abstract – Selection of caries‐risk groups is difficult and unreliable. In this study we analyzed the known correlates of caries and their interrelations. The subjects (n= 153) were seventh graders (13 yr old) from a school in Kuopio. Data were collected by mail survey (n= 150), from the clinical registers of the local health center (n= 135), and from a saliva test. In the first stage we computed the bivariate correlates between the D‐index and its traditionally defined determinants. In the second stage the predictors of caries risk were ranked using discriminant and multiple regression analyses. The bivariate correlates of caries were: DMF‐index of the previous year (r = 0.69), D‐index of the previous year (r = 0.59), lactobacillus count (r = 0.26), buffer capacity (r = 0.20), and toothbrushing frequency (r = 0.07). In discriminant analyses the DMF‐index among girls and the frequency of consumption of sweets among boys were the only significant discriminators. In the multiple regression analyses, however, the final model (P <0.001) for girls included: DMF‐index of the previous year (β= 0.64) and lactobacillus count (β= 0.31). The corresponding model for boys (P <0.001) included: DMF‐index of the previous year (β= 0.55) and frequency of consumption of sweets (β= 0.24). Using these variables, it is difficult to develop a reliable method for determining the caries susceptible groups, but of them, the DMF‐index seems the most reliable for predicting caries risk among children.
Initial corrosion of amalgams in vitro
Authors: BRUNE DAG , EVJE DAG MAGNAR
Published: October 2007

Abstract – The amounts of copper, mercury, silver or zinc released from two brands of freshly prepared, lathe cut amalgams and from one brand of dispersed phase type amalgam into artificial saliva have been measured. Samples were immersed in the solution a few minutes after the end of trituration and exposed statically for periods of up to about 4 days. The initial mercury release from such specimens could exceed the long term mercury release from old amalgams by more than two orders of magnitude. The measurements indicate that during the first day after insertion of two amalgam fillings, each with an assumed surface area of 1 cm2 and under presumably static conditions, mercury at the level of more than twice the mercury food and drink intake could be released in the oral cavity. This is, however, a situation which appears infrequently, e.g. following dental treatment once a year. The amounts of copper and zinc released initially were considerably lower than the corresponding food and drink intake values, while silver might be on the same level. The measurements were conducted using nuclear tracer techniques.
Fluoride retention in sound and demineralized enamel in vivo after treatment with a fluoride varnish (Duraphat)
Authors: ÖGAARD BJÖRN , RÖLLA GUNNAR , HELGELAND KRISTEN
Published: October 2007

Abstract – The retention of alkali soluble (CaF2) and alkali insoluble (fluorapatite) fluoride in sound enamel and demineralized enamel 2 wk after application of Duraphat was investigated in a group of orthodontic patients from whom pairs of homolog premolars were to be extracted. Demineralization of the enamel was induced during a 4‐wk period prior to application of fluoride by applying orthodontic bands to the premolars. The bands also remained attached to the teeth during and after application of fluoride (2 wk) to maintain a cariogenic environment. Three consecutive enamel layers (∼5 μm) were subsequently etched off. A significant uptake of fluoride in the first and second layer of sound enamel and in all the three enamel layers of demineralized enamel was found. More fluoride was found in demineralized enamel and a higher proportion of this fluoride was found to be in an alkali insoluble form compared with the fluoride in sound enamel. The SEM study showed a rough enamel surface after three consecutive acid etchings. The etching pattern differed within the etched area. It was suggested that the variation in etching pattern might be due to differences in orientation of the crystallites and the original surface morphology.
Variation in human oral lactobacilli following a change in sugar intake
Authors: CROSSNER CLAES‐GÖRAN
Published: October 2007

Abstract – For 19 wk oral lactobacilli was registered continuously in 10 dental hygienist students. During the study period these subjects were submitted to a change in between‐meals consumption, rinsing with chlorhexidine and determination of sugar clearance, flow rate and buffer effect of saliva. An increase in the frequency of sugar consumption increased the number of lactobacilli in saliva, and in particular of Lactobacillus casei. However, in spite of an hourly intake of sugar between 7 a.m. and 9 p.m. every day for 4 wk, this increase of lactobacilli was small. The probable reason for this was the very high dental health consciousness of the test subjects, with a perfect oral hygiene and a strong wish to have a clean taste in the mouth. The sugars were too rapidly eliminated to create such an acid oral environment as favors the aciduric lactobacilli. A week of twice daily rinsing with chlorhexidine had no obvious effect on the number of lactobacilli in saliva.
Effect of orthodontic treatment on prevalence of Streptococcus mutans in plaque and saliva
Authors: SCHEIE ANNE AAMDAL , ARNEBERG PÅL , KROGSTAD OLAF
Published: October 2007

Abstract – The effect of orthodontic treatment on the prevalence of Streptococcus mutans was investigated in 14 subjects. Insertion of appliances tended to give a transient decrease in S.mutans levels, in both plaque and saliva, possibly due to elimination of S.mutans reservoirs by the banding procedure. After 3 months of extensive banding, the S.mutans proportions surpassed pretreatment levels in saliva and on banded teeth, whereas unbanded surfaces only showed a slight increase. It was thus concluded that creation of new retentive areas favors the local growth of S.mutans, which in turn increases the general infection level of this organism. Time was, however, needed before elevated levels were reached. Insertion of appliances tended to eliminate the characteristic gradient of S.mutans levels within the dental arches.
Oral submucous fibrosis as a precancerous condition
Authors: PINDBORG J. J. , MURTI P. R. , BHONSLE R. B. , GUPTA P. C. , DAFTARY D. K. , MEHTA FALI S.
Published: October 2007

Abstract – An evaluation of the malignant potential of submucous fibrosis, based on observations of 89 patients with the disease in Ernakulam District, Kerala, India was done. Out of the 89 patients, 12 were referred patients and 77 were diagnosed in population based studies. At the time of first examination oral cancer was found to be coexistent in nine (10%) cases. For 66 patients follow‐up observations ranging from 4 to 15 yr (median 8 yr) were available. During this period malignant transformation was observed in three patients (4.5%). Considering malignant transformation and coexistence together, oral cancer was observed in 13% of the present material. Leukoplakia was found in 26% of the patients with submucous fibrosis. Out of 42 submucous fibrosis patients biopsied, 12% showed squamous cell carcinoma, 26% epithelial dysplasia, and 76% atrophic epithelium. These findings reinforced the hypothesis that submucous fibrosis is a precancerous condition.
IgA deposits in the oral mucosa of patients with dermatitis herpetiformis and linear IgA disease
Authors: HIETANEN JARKKO , REUNALA TIMO
Published: October 2007

Abstract – The oral mucosa of seven patients with dermatitis herpetiformis (DH) and one with linear IgA disease was studied. None of the patients with DH showed any macroscopic oral lesions, but direct immunofluorescence (IFL) examination of the buccal mucosa revealed granular IgA deposits in all patients. IgA deposits were found just below the basement membrane zone or slightly deeper in the connective tissue, i.e. a deposition pattern which is pathognomonic to DH. In three patients C3 deposits occurred in the same area as IgA. The patient with linear IgA disease had small white erythematous patches, nonspecific both clinically and histologically, on the palatal mucosa. However, oral IFL specimens showed heavy linear IgA deposits in the basement membrane zone, indicating that the oral mucosa is also involved in this rare disease. Buccal mucosal biopsy specimens were stained with four FITC‐conjugated lectins (Ulex europaeus I, soybean, peanut and lentil). The lectin staining was similar in patients with DH and linear IgA disease and did not markedly differ from normal oral mucosa. Our results show that buccal IFL examination is a useful diagnostic aid in both DH and linear IgA disease.
Enumeration of T cell subsets with monoclonal antibodies in minor salivary glands of patients with rheumatoid arthritis
Authors: SYRJÄNEN STINA M. , SYRJÄNEN KARI J.
Published: October 2007

Abstract – Labial salivary glands of 51 patients with rheumatoid arthritis and those of 25 control patients were examined by the ANAE (acid α‐naphthyl acetate esterase) technique to determine the percentages of B‐ and T‐lymphocytes and mononuclear phagocytes (MPS cells). Using monoclonal antibodies (OKT3 for all T cells, OKT4 for helper/inducer T cells, OKT6 for thymocytes, and OKT8 for suppressor/cytotoxic T cells) T cell subsets were enumerated. B‐ lymphocytes predominated in both series of salivary glands, and the percentages of B and T cells were equal in both series. The absolute cell counts in the salivary glands of rheumatics were significantly higher (P<0.001) than in those of healthy controls. The number of OKT4+ cells was increased in rheumatics, leading to an elevated OKT4+/OKT8+ ratio when compared with that in controls (P<0.01). The results suggest that the basic phenomenon behind the B cell hyperactivity noticed in rheumatics might be due to increased activity of T helper cells rather than reduced number of T suppressor cells, which were shown to remain almost unaffected in the salivary glands of patients with rheumatoid arthritis.
Salivary viscosity and lubrication: influence of pH and calcium
Authors: NORDBÖ HÅKON , DARWISH SAMIA , BHATNAGAR RAJENDRA SAHAI
Published: October 2007

Abstract – The viscosity of human whole saliva and six salivary protein fractions was studied at different pH levels in the presence and absence of calcium. Changes in pH significantly influenced the viscosity of whole saliva, and centrifugation and filtration removed one of the viscous components. Calcium depletion made the viscosity particularly susceptible to acidification. The protein fractions were obtained from pooled parotid saliva by ion exchange and gel permeation chromatography procedures. Except for a glycoprotein, these fractions generally exhibited the lowest viscosity in the pH region around their isoelectric points. Calcium generally increased the viscosity of these proteins.
Stimulated salivary flow rate, pH and lactobacillus and yeast concentrations in non‐smokers and smokers
Authors: PARVINEN TUIJA
Published: October 2007

Abstract – The effect of smoking habit on flow rate, pH and lactobacillus and yeast counts of paraffin stimulated whole saliva was analyzed in an unmedicated adult population of 462 non‐smokers and 180 smokers. Regular but not immediate smoking was not associated with any significant changes in the salivary flow rate. The pH of stimulated whole saliva was in both sexes lower in smokers than in non‐smokers, the differences between the groups being statistically significant. Smoking did not affect salivary yeast counts, but smokers did show increased proportions of high lactobacillus counts.
Role of brushing technique and toothbrush design in plaque removal
Authors: BERGENHOLTZ AXEL , GUSTAFSSON LENNART B. , SEGERLUND NILS , HAGBERG CATHARINA , ÖSTBY PER NYGAARD
Published: October 2007

Abstract – Twenty‐four adults participated in an intraindividual crossover experimental study to compare the plaque removing ability of straight multitufted and V‐shaped brushes. Twelve of the participants had loss of periodontal tissue resulting in open but healthy interdental areas while the other 12 displayed no periodontal breakdown. In part 1 the participants were asked to brush their teeth using their own brushing technique and length over two 12‐day periods during which time they, at random, used one brush for the first and the other brush for the second period. In part 2 the participants were professionally brushed by two dental assistants using four brushing techniques (The Bass, The Roll, The Circular Scrub and The Horizontal Scrub) randomly assigned to the four quadrants of the mouth. Cleaning was performed once a day for two 5‐day periods, during which time the participants refrained from brushing and interdental cleaning. Initial toothbrush assignment was randomized. At the beginning of the study and each test period no plaque or gingival inflammation was visible. At the end of each period the accumulated plaque was registered. The results showed that there was no difference between the two brushes tested in the unsupervised part. The plaque removing ability when using either of the brushes varied between participants. When professionally used the straight multitufted and V‐shaped toothbrushes did not show any difference in plaque removal on buccal and lingual surfaces. Interproximally the V‐shaped toothbrush was better at plaque removal than the straight one. However, plaque still remained after brushing with the V‐shaped toothbrush, which indicates that toothbrushing always must be supplemented with interdental aids and that the shape of brushes as well as the techniques used are of little importance. Interproximal areas with tissue breakdown and loss of interdental papillae accumulated more plaque than those with no periodontal tissue breakdown.
Histology, innervation and radiographic appearance of fetal rat tooth germs developing in oculo
Authors: GRANHOLM ANN‐CHARLOTTE
Published: October 2007

Abstract – Rat molar and incisor tooth germs from gestational days 18–21 were homologously grafted to the anterior eye chamber of adult recipients. The fetal tooth transplants survived and grew considerably in the eye, attached to and vascularized from the anterior surface of the host iris. Grafts were examined histologically and compared with in situ controls after up to 6 months in oculo. Radiographic examinations of the grafts showed a normal rate of mineralization and a distinct enamel/dentin border after intraocular development. The size of the tooth grafts was somewhat smaller than in situ but the grafted teeth attained a form much resembling in situ incisors and molars. Light microscopy revealed a regular dentin and predentin, a distinct dentin/enamel border and a well innervated and vascularized pulp. No degenerative changes in dentin or enamel layers could be found in long‐term grafts (6 months). Thus, intraocular tooth grafts in rats develop many histologic and anatomic features typical of normal teeth, emphasizing the importance of intrinsic regulatory mechanisms in tooth development.
Surgical treatment of ankylosed and infrapositioned reimplanted incisors in adolescents
Authors: MALMGREN BARBRO , CVEK MIOMIR , LUNDBERG MARGARETA , FRYKHOLM ANDERS
Published: October 2007

Abstract – A method for preserving the alveolar ridge of ankylosed and infrapositioned incisors and improving conditions for a subsequent prosthetic therapy is described and evaluated clinically and radiographically. The method involves removal of the crown and root filling from the root, which is retained and covered with a mucoperiosteal flap. Clinically, there were no postoperative complications and after the follow‐up a satisfactory prosthetic restoration was performed in all cases, regardless of the degree of infraposition before treatment. Radiographically, no pathologic changes were observed apart from a continuous resorption and replacement of lost root substance by bone. Alveolar bone level shifted only slightly between postoperative and 12‐month follow‐up radiographs, in a majority of cases in a coronal direction.